GB2478021A

GB2478021A - A liquid heating vessel

Info

Publication number: GB2478021A
Application number: GB1017391A
Authority: GB
Inventors: David Andrew Smith; Robert Henry Hadfield; Antonio Martin Gaeta; Ian Geoffrey White; Robin Keith Moore; Yuan An; Peter Hallam Wright; Jeremy Francis Siddons; Andrew Hunt; Paul Boundy; Simon M Whiteley
Original assignee: Otter Controls Ltd
Current assignee: Otter Controls Ltd
Priority date: 2010-02-18
Filing date: 2010-10-14
Publication date: 2011-08-24
Also published as: EP2536317A2; GB2478163A; GB2478163B; GB201008015D0; GB201002777D0; JP5950829B2; GB201019649D0; JP2013519485A; GB2477944A; CN102762135B; GB2478026A; GB201021926D0; GB201003471D0; GB2477944B; GB201003611D0; CN102762135A; GB201017391D0; WO2011101642A2; WO2011101642A3

Abstract

A liquid heating vessel comprising a removable and replaceable component 150 which includes a lid and a hinge mechanism integrated with the component. The component may include an integral handle and/or spout, and there may be sealing means for sealing the component to the vessel. Other aspects relate to a sealing means for selectively sealing against an outlet for dispensing liquid from a chamber of the vessel, means for controlling the temperature of the liquid depending on a comparison of the temperature sensed by sensors and a spill-inhibiting apparatus for the vessel. In a further aspect the vessel has a capacitive liquid level sensor, in another it comprises an optical beam detector for detecting boiling and simmering of the liquid. Other aspects also relate to a cordless electrical appliance with an optical coupling between the appliance and a base of the appliance, a cordless electrical connector having an optically transmissive main moulding arranged to provide an electrical coupling and a user interface for a liquid heating appliance.

Description

Electrical Appliances

Field of the Invention

[0001] The present invention relates to electrical appliances and components therefor. Some aspects of the invention are directed to cordless electrical appliances. Other aspects are directed to liquid heating appliances with safety features to reduce or eliminate spillage if the appliance is accidentally tipped or knocked over. Other aspects are directed to liquid level sensors for liquid vessels.

Background of the Invention

[0002] In a cordless appliance, the appliance proper includes a cordless connector that is operable to cooperate with a corresponding cordless connector on a power base. Thus, when the appliance proper is mounted on the power base, power may be supplied to the appliance proper. Such arrangements allow a power base to be connected to a domestic power supply (such as by a plug), whilst further allowing the appliance proper to be removed from the base for various operations, such as dispensing heated liquid from a cordless liquid heating appliance. The above types of cordless electrical connectors have also found use on other domestic appliances, such as food processors, blenders and the like. This arrangement provides an advantage that the processed/blended food can be more easily dispensed by a user.

[0003] 360° cordless connectors, as described for example in WO-A-94/06185, allow the appliance proper to be rotated freely relative to the power base, so that the appliance proper may be positioned on the power base with any azimuthal orientation.

[0004] However, as will be appreciated, appliances such as food processors, blenders and, to a lesser extent kettle jugs, need regular cleaning. In particular, cordless appliances for containing food or liquids other than water require cleaning after each use. Such a task is time consuming and may be difficult to perform manually.

[0005J It would be desirable to provide a cordless appliance where the detachable part of the appliance can be washed in a dishwasher, by immersion in water or otherwise easily cleaned. Sealing arrangements for such a washproof appliance are disclosed in WO-A-09/109762.

[0006] It would be preferable to minimize the components in the appliance proper that need to be seated, such as electrical components. For example, electrical power switching components may be located in the power base, but this requires some means of signalling the state of the appliance proper to the power base, so that power may be switched in response to the state of the appliance proper.

[0007] One way of signalling from the appliance proper to the power base is to provide additional electrical contacts therebetween, for example as disclosed in GB-A-2378818 or in WO-A-01/282294. However, these additional contacts must themselves be sealed if the appliance proper is to be washable. Moreover, any debris on the low voltage contacts may prevent electrical contact from being made, and the debris will not be burnt away as might occur on high-voltage contacts.

[0008] WO-A-2008/155538 discloses a cordless appliance with wireless signalling between the appliance proper and the base, for example by means of a circular light guide concentric with a cordless electrical connector. Whilst this arrangement is advantageous in that it allows signalling between the appliance proper and the base while allowing the use of 3600 cordless connectors, the arrangement requires additional optical connecting components which add to the complexity of the arrangement.

[0009] With electrical liquid heating appliances, there is a risk of spillage of hot liquid if the appliance is accidentally tipped or knocked over. Since the liquid may be at or close to boiling, such spillage can cause severe scalding to the user or bystanders.

[0010] There have been many proposals in the state of the art to reduce or inhibit such spillage, most of which are impractical or at least have never been incorporated into commercial products. The solutions proposed in the state of the art are generally one of two types: automatic types in which liquid can only be poured out when the appliance is in a particular orientation, and manual types in which liquid can only be poured out when an interlock is manually released. The state of the art is mostly directed to domestic water boiling appliances, referred to hereafter as safety kettles.

[0011] One particular problem common to both types is the need to allow pressure release, particularly to release steam pressure within the appliance. For example, JP-A-2008212315 discloses a manual type safety kettle with a separate venting outlet for steam. In tests of a Tiger' brand kettle commercially available in Japan and based on the disclosure of that patent application, boiling water spurted vigorously from the venting outlet when the kettle was tipped onto its side. However, if the heating vessel were completely closed by the interlock, as for example in GB-A-2272629, there is a risk that steam pressure will build up inside the vessel until it explodes. GB-A-2305353 discloses a safety kettle with a steam valve that closes when the kettle is tipped over. However, in the case of a corded kettle, the water may continue to boil after the kettle is tipped over, so that steam pressure builds up inside the kettle. In the case of a cordless kettle, the temperature difference between the heating element and the water may cause boiling to continue for a short while after the kettle is knocked over, so that pressure would also build up to some degree.

[0012] Automatic-type safety kettles generally do not address the problem of pressure build-up. For example, GB-A-2 189378 discloses a spout flap that closes automatically if the kettle is not orientated correctly for pouring. DE-A-197408261 discloses a kettle lid that can only be opened when the kettle is upright.

[0013] Another problem to be addressed in safety kettles and the like is the need to allow easy filling and pouring. In the state of the art, the safety features intended to inhibit spillage also tend to make pouring or filling more difficult.

[0014] Another problem to be addressed is the reliable detection and/or indication of liquid level in a vessel when the vessel is at a substantial angle from the vertical, such as when the vessel is tipped forwards or backwards for filling. WO-A-2008/155538 discloses a magnetic float arranged to actuate one or more of a series of reed switches at different heights; alternatively, an array of electrodes or capacitive level sensors may be used. WO-A- 2008/119966 discloses the use of a capacitive level sensor array positioned around the perimeter of a kettle, either within or outside the water reservoir, to measure the water level when the kettle is at an angle.

[0015] A problem with liquid heating appliances, particularly ones where the user may control the volume of liquid to be dispensed and/or heated, and the temperature to which the liquid is to be heated, is that the user interface becomes complex and unintuitive, particularly where separate user-actuable controls are required to set the volume and the temperature.

[0016] A problem with liquid heating appliances that heat a small quantity of liquid is the need to dispense all the water that has been boiled in a speedy manner to minimise the energy wastage.

[0017] Another problem with liquid heating appliances that heat a small quantity of liquid is the difficulties in sensing and controlling the liquid temperature. WO-A-2009/060 192 discloses a method of detecting boiling or simmering in a liquid heating vessel by emitting electromagnetic radiation towards the surface of the liquid and detecting reflection of the radiation from the surface, or transmission of the radiation through the surface, either of which are affected by turbulence in the surface, characteristic of simmering or boiling.

[0018] There is a need to implement this method in a manner that is tolerant to the characteristics of the liquid as it is heated and tolerant to different appliance types, particularly where the appliance types are partially or completely manufactured from a transparent or internally reflective material.

[0019] In addition, the method should preferably operate across a range of liquid levels and a range of translucency of the liquid, either as an inherent characteristic of the liquid or a transient state of translucency of the liquid, for example due to aeration. The method also needs to be tolerant of the characteristics of components and the effect of usage and aging in the appliance, for example scale build up on the emitters and receivers.

[0020] There is a need to save energy when heating liquids for domestic use. It is known that energy can be saved in the following manner: * Heating only the amount of liquid required (e.g. Hot Water on Demand) * Heating the liquid to the required dispensing temperature.

* Quickly dispensing all the liquid heated.

Whereas the above solutions are well known, the practical implementation, particularly for volumes as low as 1 50m1 in high power appliances, is difficult to achieve.

[0021] In particular, there are problems to overcome in sensing or controlling the liquid temperature, particularly the temperature lag between the heating means and the liquid to be heated, and the resultant overshoot of the heat into the liquid after the heater has been de-energised.

[0022] WO-A-20 10/094945 discloses methods to alleviate the overshoot by adding additional liquid into the vessel after the liquid has boiled and also discloses methods to mix cooler liquid with boiled liquid so that the dispensed liquid is at a temperature below boiling.

Statement of the Invention

[0023] According to one aspect of the present invention, there is provided a user interface for a liquid heating appliance, the interface being rotationally actuable to select first and second parameter value settings for the appliance.

[0024] The interface may be arranged to cycle through discrete values of the first parameter setting, while changing the value of the second parameter setting on each said cycle, in response to said rotational user actuation.

[0025] Alternatively, the user interface may be responsive to a further user actuation by switching between changing the first and second parameter value settings in response to said rotation user actuation.

[0026] The user interface may include means for indicating the selected first and second parameter value settings; this may comprise a display located within a rotationally actuable portion of the user interface.

[0027] A portion of the user interface may be mechanically rotatable, and/or touch sensitive.

[0028] The first parameter may comprise a temperature to which liquid is to be heated. The second parameter may comprise a volume of heated liquid to be dispensed.

[0029J According to another aspect of the present invention, there is provided a user interface for a liquid heating appliance, having a rotational user actuator to select at least first and second parameter settings for the appliance.

[0030] According to another aspect of the invention there is described means to control and dispense small volumes of liquid.

100311 According to another aspects of the invention there is described an appliance that heats and dispenses small volumes of liquid.

[0032] According to another aspect of the invention, there is provided a spill-inhibiting apparatus for a liquid heating vessel having an outlet for dispensing liquid, the apparatus having a valve through which the liquid can be dispensed, the valve being arranged to close when the vessel is tipped to one side relative to the outlet, and to open when the vessel is tipped towards the outlet. This provides a convenient arrangement for reducing spillage, without requiring the user to manually open the vessel for dispensing. The arrangement may include a valve sealing or operating member that moves to one side or the other under gravity.

[00331 According to another aspect of the present invention, there is provided a spill-inhibiting apparatus for a liquid heating vessel having a valve through which liquid can be dispensed, the valve being arranged to open under steam pressure within the vessel, and being arranged to close when the vessel is tipped over. In this way, a single valve provides both steam venting and spill prevention from the vessel.

[0034] The valve may comprise an overcentre mechanism that closes the valve when the vessel is tipped.

[0035] Preferably, the valve is arranged to be normally closed when the vessel is in an upright orientation. In this way, thermal losses through the valve can be reduced. The valve may have first sealing faces that close when the vessel is in an upright orientation, and second sealing faces that close when the vessel is tipped.

10036] The valve may be prevented from closing when the vessel is tipped by a user-actuated mechanism, to allow dispensing of liquid through the valve. Alternatively or additionally, the valve may be prevented from closing when the vessel is tipped in a specific orientation, without the need for user actuation of the valve.

[0037] According to another aspect of the invention, there is provided a spill-inhibiting apparatus for a liquid heating vessel having an outlet for dispensing liquid from the vessel, and a user actuated mechanism arranged to open the dispensing outlet for dispensing when actuated. The user-actuated mechanism may be biased to a closed position so that liquid cannot be dispensed through the dispensing aperture. In one embodiment, in the closed position the dispensing outlet is open to a steam passage that opens towards an opposite side of the vessel from the dispensing outlet. In another embodiment, there is provided a separate steam outlet from the dispensing outlet. The separate steam outlet may be closed by a valve that opens under steam pressure, but may close when the vessel is tipped.

100381 According to another aspect of the invention there is described a removable lid assembly that incorporates a hinge lid part.

[0039] According to another aspect of the invention there is described a removable lid assembly that incorporates a hinge lid part and spill inhibiting features.

[0040] According to another aspect of the present invention, there is provided a liquid vessel having a liquid reservoir and a capacitive liquid level sensor for sensing the liquid level within the reservoir, the sensor comprising a plurality of capacitor plates each extending in a vertical direction of the reservoir and making a capacitive coupling with liquid within the reservoir through a portion of the wall of the reservoir, the capacitor plates being mutually spaced apart around the circumference of the reservoir such that the combined capacitance through the capacitor plates is representative of the volume of liquid within the reservoir, substantially independently of the angle of tipping of the reservoir.

[0041] Preferably, the vessel has an outer wall outside the wall of the reservoir.

[0042] The vessel may include means for indicating the volume of liquid within the reservoir in response to the liquid level sensor. The means for indicating may be substantially continuously variable, or may be responsive to one or more liquid level thresholds being exceeded.

[0043] According to another aspect of the present invention, there is provided a cordless electrical appliance comprising an appliance proper and a power base connectable together by means of respective cordless electrical connectors, the appliance proper having a component sealed therein by means of a seal and being arranged to communicate with the power base by means of electromagnetic radiation conveyed through the seal. Preferably, the electromagnetic radiation comprises light and the seal is arranged to act as a light guide for the light.

[0044] Advantageously, this arrangement allows wireless signalling between the appliance proper and the base without the need for an additional light guide, thereby allowing the appliance proper to be made washable with fewer components.

[0045] The seal may be concentric with the cordless electrical connector on the appliance proper, and the power base may include optical communication means arranged to interact with the seal when the appliance proper and the power base are connected electrically together, regardless of the relative rotation of the cordless electrical connectors.

Advantageously, this arrangement allows the use of 360° cordless connectors. The seal may be arranged to seal the cordless electrical connector within the appliance proper.

100461 The seat within the appliance proper and/or the power base may include an optical transmitter and/or receiver located within the seal, for example within a pocket in the seal.

This arrangement improves the optical coupling between the seal and the transmitter and/or receiver.

[0047] An additional light guide may be positioned in optical communication with the seal and within the power base and/or electrical appliance.

[0048] According to another aspect of the present invention, there is provided a cordless electrical appliance comprising an appliance proper and a power base, wherein a first, unidirectional signalling link is provided between the appliance proper and the power base, and a second, discrete signalling link is provided between the appliance proper and the power base.

10049] The second signalling link may be unidirectional, in a direction opposite to that of the first signalling link. One of said first and second signalling links may be an optical signalling link, while the other one may be an electrical signalling link. The electrical signalling link may be through one or more power terminals of a cordless electrical connection between the appliance proper and the base.

[0050] According to another aspect of the present invention, there is provided a liquid heating vessel, comprising: a. an emitter arranged to direct an optical beam towards the surface of liquid within the vessel; b. a receiver aligned with said optical beam to receive said optical beam passing through said surface; and c. a detector for detecting variations in the level of the received optical beam so as to detect simmering or boiling of the liquid; wherein the emitter is arranged above the surface of the liquid and the detector is arranged below the surface of the liquid.

[0051] According to another aspect of the present invention, there is provided a liquid heating vessel, comprising: a. an emitter arraiiged to direct an optical beam towards the surface of liquid within the vessel; b. a receiver aligned with said optical beam to receive said optical beam passing through said surface; and c. a detector for detecting variations in the level of the received optical beam so as to detect simmering or boiling of the liquid.

wherein the emitter is arranged to direct the beam substantially orthogonally to said surface.

[0052] According to another aspect of the present invention, there is provided a method of detecting simmering or boiling of a liquid in a liquid heating vessel, the method comprising: a. illuminating the surface of the liquid with an optical signal; b. detecting the optical signal as received from the surface; c. determining a normalised level of variation of the received optical signal; and d. comparing the normalised level of variation with a predetermined criterion so as to detect simmering or boiling of the liquid.

[0053] According to another aspect of the present invention, there is provided a method of detecting simmering or boiling of a liquid in a liquid heating vessel, the method comprising: a. illuminating the surface of the liquid with a modulated optical signal; and b. detecting the optical signal as received from the surface, so as to detect simmering or boiling of the liquid; wherein the modulation of the modulated optical signal is adjusted so as to maximize the detected optical signal.

[0054] According to another aspect of the present invention, there is provided a method of detecting simmering or boiling of a liquid in a liquid heating vessel, the method comprising: a. illuminating the surface of the liquid with an optical signal; and b. detecting the optical signal as received from the surface, so as to detect simmering or boiling of the liquid; wherein the level of the received optical signal is adjusted so as to improve detection of simmering or boiling.

[0055] According to another aspect of the invention there is provided a water proof or washproof liquid heating appliance including any or all of the other inventions described herein.

Brief Description of the Drawings

[0056] There now follows, by way of example only, a detailed description of preferred embodiments of the present invention, with reference to the figures identified below.

Figure 1 is a schematic cross-section of a cordless liquid heating appliance in an embodiment of the invention.

Figure 2 is a schematic diagram of the electrical and optical components of the cordless liquid heating appliance.

Figure 3a is an isometric view of a waterproof cordless connector for a vessel body in an embodiment of the invention.

Figure 3b is an exploded view of the underside of the waterproof cordless connector for the vessel body.

Figure 4a is an isometric view of a waterproof cordless connector for a power base in an embodiment of the invention.

Figure 4b is an isometric view of the underside of the waterproof cordless connector for the power base.

Figure 4c is an exploded view of the waterproof cordless connector for the power base.

Figure 5 is a cross-section of the waterproof cordless connectors for the vessel body and the power base, connected together.

Figure 6 is a side view of a waterproof cordless connector for the vessel body, in an alternative embodiment.

Figure 7 is a side view of a waterproof cordless connector for the vessel body, in another alternative embodiment.

Figure 8a is a schematic cross-section of a liquid heating appliance with a spill-inhibiting safety feature in an embodiment of the invention.

Figures 8b to 8e show details of the safety feature, respectively in rest, boiling, pouring and tipping positions.

Figures 9a to 9c show details of an alternative safety feature, respectively in boiling, pouring and tipping positions.

Figures lOa to lOc show details of another alternative safety feature, respectively in boiling, pouring and tipping positions.

Figure 11 a is a schematic cross-section of a liquid heating appliance with a spill-inhibiting safety feature in another embodiment of the invention.

Figure 1 lb is a cut-away perspective view of a lid chamber arrangement of the embodiment of Figure 11 a.

Figures ii c and lid are schematic cross-sections of a venting arrangement of the embodiment of Figure 11 a, with the user actuator in a normal position and actuated position respectively.

Figures lie and 11 f are schematic cross-sections of an alternative venting arrangement of the embodiment of Figure 1 la, with the user actuator in a normal position and actuated position respectively.

Figures 11 g and 11 h are schematic cross-sections of another alternative venting arrangement of the embodiment of Figure 11 a, with the user actuator in a normal position and actuated position respectively.

Figures 11 i, 1 lj and ilk are schematic cross-sections of yet another alternative venting arrangement of the embodiment of Figure 11 a, in upright, pouring and tipping configurations respectively.

Figures 111 and 1 im are schematic cross-sections of another alternative venting arrangement of the embodiment of Figure 1 la, with the user actuator in a normal position and actuated position respectively.

Figure 12a is a schematic cross-section of a liquid heating appliance with a spill-inhibiting safety feature in another embodiment of the invention.

Figure 1 2b is a perspective view of a lid chamber arrangement of the embodiment of Figure 12a, with the upper part of the lid removed.

Figures 12c and 12d are schematic cross-sections of the pouring aperture of the embodiment of Figure 1 2a, respectively in open and closed configurations.

Figure 13a is a schematic cross-section of a liquid heating appliance with a spill-inhibiting safety feature in another embodiment of the invention.

Figure 13b is a perspective cut-away view of the pouring aperture of the embodiment of Figure 13a.

Figure 13c and 13d are schematic cross-sections of the valve arrangement of the embodiment of Figure 13a, respectively in rest and pouring configurations.

Figures 13e to 13g are schematic cross-sections of an alternative valve arrangement of the embodiment of Figure 13a, respectively in rest position, pouring position and tilted to one side, viewed from the rear of the appliance.

Figure 1 4a is an exploded diagram of a lid with a spill-inhibiting safety feature in another embodiment of the invention.

Figure 14b is a perspective view of the lid in a pouring position.

Figure 14c is a perspective view of the lid when tipped over on one side.

Figure iSa is an exploded diagram of a lid with a spill-inhibiting safety feature in another embodiment of the invention.

Figure lSb is a close-up perspective view of a pendulum of the lid.

Figure lSc is a cut-away cross-section of the lid in pouring position.

Figure 1 Sd is a cut-away cross-section of the lid when tipped over on one side.

Figures 1 6a and 1 6b are plan views of a lid in another embodiment of the invention, including a venting feature.

Figure 17 is an exploded diagram of a lid with a spill-inhibiting safety feature in another embodiment of the invention.

Figures 1 8a and I 8b are plan views of the lid of Figure 17, in pouring and tipped over positions respectively.

Figures 1 9a and 1 9b are cut-away isometric views corresponding to Figures 1 8a and 18b respectively.

Figures 20a and 20b are respectively exploded and cut-away isometric views of a spill-inhibiting lid in another embodiment of the invention.

Figures 21 a and 2 lb are respectively a perspective and a cross-sectional view of a waterproof appliance with a removable lid, in another embodiment of the invention.

Figure 22 is a cross-sectional view of a waterproof appliance with a removable lid, in another embodiment of the invention.

Figure 23a is a schematic diagram of a liquid vessel with a single strip capacitance level sensor.

Figure 23b is a graph showing the capacitance of the double strip capacitance sensor with fill level.

Figure 24a is a schematic diagram of a liquid vessel with a double strip capacitance level sensor.

Figure 24b is a graph showing the capacitance of the double strip capacitance sensor with fill level.

Figure 24c is a schematic diagram showing the effect of tilt on the double strip capacitance level sensor.

Figure 24d is a graph showing the effect of tilt on the capacitance of single strip and double strip capacitance level sensors.

Figure 25 is a circuit diagram of a circuit for generating a frequency as a function of the capacitance of the level sensor.

Figure 26 is a circuit diagram of a circuit for detecting electronically whether the capacitance of the level sensor is above a first or a second threshold.

Figure 27 shows a rotationally actuable user interface component in an embodiment of the invention.

Figures 28a to 28d illustrate display states of the component with varying selected temperatures.

Figures 29a to 29d illustrate display states of the component with varying selected volumes.

Figures 30a and 30b are graphs of detected optical signal amplitude in a turbulence detection method, respectively without and with scale deposit.

Figure 31 is a graph of the gain and phase response of typical band-pass filter.

Figure 32 is a graph of a transmitted signal (square wave) at centre frequency of a band-pass filter.

Figure 33 is a graph of the transmitted signal (square wave) at 95% of centre frequency of a band-pass filter.

Figure 34 is a graph of the transmitted signal (square wave) at 105% of centre frequency of a band-pass filter.

Figure 35 is a graph illustrating a quadrature measurement method.

Figure 36 is a graph illustrating a fixed phase measurement method.

Figure 37a is an isometric cross-section of a vessel including a turbulence detector.

Figure 37b is an isometric view of the underside of the vessel of Figure 37a.

Figure 37c is an isometric view of the vessel of Figure 34a with the top part of the handle removed.

Figure 38 is a cross-sectional view of a vessel for heating and dispensing small volumes of water, in an embodiment of the invention.

Figure 39a is a cross sectional view of an alternative embodiment to that of Figure 38.

Figures 39b and 39c are cross-sectional views of alternative sealing arrangements in the embodiments of Figure 38 or 39a.

Figure 39d and 39e are cross-sectional views of optional support means in the embodiments of Figure 38 or 39a.

Figure 40 is a cross sectional view of an alternative embodiment to that of Figure 38 or39a.

Figure 41a, 41b, 42a and 42b are cross sectional views of further alternative embodiments.

Figure 41 c is a perspective view of an intermediate part of the embodiment of Figure 41b.

Figures 43 and 44 are respectively elevation and perspective views of an appliance incorporating one or more of the embodiments described herein.

Figures 45a is a side elevation of another appliance incorporating one or more of the embodiments described herein.

Figure 45b is a perspective view of the appliance of Figure 45a, with the reservoir separated.

Detailed Description of the Embodiments

[0057] In the following description, functionally similar parts carry the same reference numerals between different embodiments. The drawings are intended to be schematic, and dimensions and angles may not be determined accurately from them.

Cordless Electrical Appliance with Optical Coupling 100581 Figure 1 shows schematically a jug kettle with an electronic control, as an example of an appliance to which embodiments of the invention may be applied. In this example, the kettle is a cordless kettle comprising a vessel body 1 and a power base 2 having respective body and base cordless connectors 3 and 4, such as 360° cordless connectors of the type described in patent publication WO-A-94/06285 and/or as sold by Otter Controls Ltd. under the CS4/CS7 (power base socket) and CP7 or CP8 (appliance plug) references. The power base is connectable by a power cord 13 to an electrical power outlet (not shown).

[0059] The vessel body 1 comprises a reservoir 5 for containing liquid to be heated, and a base section 6 having a sub-base 19, which forms the bottom surface of the vessel body 1.

The vessel body 1 is formed as a jug kettle and therefore has a spout 7, a lid 8 and a handle 9. Liquid is heated by an element plate 12 forming the base of the reservoir 5, and including a heating element on the underside (i.e. facing towards the base section 6), connected to receive electrical power from the body cordless connector 3. The element plate 12 may be fitted into the vessel body using the Easifix (RTM) fitting as described in WO-A-99/17645.

The element may comprise a sheathed element and/or a thick film element. Preferably, the element plate is composed of stainless steel. Most preferably, the element plate is substantially as described in WO-A-06/83 162. However, at least some embodiments of the present invention are applicable to liquid heating vessels having an immersed heating element, rather than an element plate.

[0060] A sensor 14 is arranged to sense the state of liquid in the reservoir 5. The sensor 14 is connected to an appliance control 15 which communicates with a base control 10 by means of an optical signal which is conveyed (as shown by a dashed line) through the cordless connectors 3 and 4. A user interface 11 allows the user to operate the vessel, and may provide a display of the operational state of the vessel. The user interface may be provided in the vessel body 1 and/or in the power base 2.

[0061] The operational state of the vessel is controlled in response to the sensor 14 and the user interface 11, by means of communication between the appliance control 15 and the base control 10. One example will now be described with reference with Figure 2.

[0062J The optical communication link between the vessel body I and the base 2 comprises an optical emitter and/or detector 31 in the base 2, which communicate respectively with an optical emitter and/or detector 31 in the vessel body 1, by means of an optically transmissive seal 21 which allows 360° of relative rotation between the base 2 and the body 1.

[0063] A power control 18 is provided in the vessel body 1 and is arranged to switch the supply of electrical power to the element plate 12, under the control of the vessel control 15.

A vessel PSU (power supply unit) 17 provides a low voltage power supply to the vessel control 15, which may be a microcontroller. A base PSU 16 provides a low voltage power supply to the base control 10, which may be a microcontroller.

[0064] The user interface 11 may be divided between the base 2 and the vessel body 1 as follows. The base 2 includes LED status indicators ha, user input means 1 lb (such as push buttons or switches) and/or audible output means 11 c, such as a piezoelectric sounder. The vessel body 1 may include lighting means 11 d arranged to illuminate a part of the vessel body 1 and/or the contents of the reservoir 5, so as to indicate the state of the vessel and/or to provide an aesthetic effect.

[0065] Hence, in this embodiment it is necessary for the base control 10 to communicate with the vessel control 15, for example to switch the power to the element plate 12 in response to a user input at the user input means 1 lb. This communication is provided by means of the optical communications link.

[0066] In other embodiments, the power control 18 may be provided in the base 2, so that it is necessary for the vessel control 15 to communicate with the base control 10 in order to switch power in response to an input from the sensor 14. In this embodiment, the optical communication may be unidirectional from the body 1 to the base 2, which is advantageous in that the optical communications link is simplified. However, the optical communication between the vessel body 1 and the base 2 may be unidirectional or bi-directional, depending on what information needs to be communicated. The same optical communications link may be used to support multiple functions between the power base 2 and the vessel body 1.

[0067] In general, it is easier to implement unidirectional communication than bidirectional communication through a particular communications link. Hence, where bidirectional communication is required between the power base 2 and the vessel body 1, an optical coupling as described above may be used for communication in one direction, and an alternative method of communication may be used in the other direction. The alternative method may comprise electrical signalling through the power terminals of the cordless connectors 3 and 4, for example as described in WO-A-07/101998, or through additional electrical signalling terminals.

[0068] In one preferred embodiment, optical signalling is used for communication from the vessel body 1 to the base 2, while electrical signalling is used for communication in the opposite direction. This is advantageous particularly for signalling over the power terminals, which is more easily implemented at the power supply side.

10069] In an alternative embodiment, the vessel control 15 may simply communicate the output of the sensor 14 optically to the base control 10. In yet another embodiment, the vessel control 15 may be dispensed with altogether, and the sensor 14 may provide a direct optical output. For example, the sensor 14 may be arranged to detect light reflected off or passing through the surface of liquid in the reservoir 5, as described for example in WO-A- 2009/060 192, or in further embodiments described hereafter. Light may also be conveyed to the surface of the liquid through the optical interface between the vessel body 1 and the base 2. In this embodiment, the sensor 14 may simply comprise a light guide, which therefore provides a very simple sensing arrangement within the vessel body 1.

[0070] It will be apparent from the above discussion that control, power switching, user interface and sensing functions may be distributed in many different ways between the body 1 and the base 2, any of which may require unidirectional or bidirectional optical communication between the body 1 and the base 2.

Cordless Optical Communication through Seal [0071] The cordless connector 3 of the vessel body 1 will now be described in more detail with reference to Figures 3a, 3b and 5. The cordless connector 3 is attachable to the sub-base 19 by attachment means such as bosses 3a. A seal 21 is provided around the circumference of the connector 3 for sealing against the sub-base 19 to prevent liquid entering the base portion 6. The seal 21 preferably comprises a main body 22 that fits against the outer side wall of the connector 3, and one or more circumferential protrusions or fins 23 extending between the connector 3 and the sub-base 19. As shown in Figure 5, the fins 23 deform against a side wall of the sub-base 19 and thereby seal the gap between the connector 3 and the sub-base 19, which gap may be variable in size depending on the tolerances and/or thermal expansion of the components.

[0072] At least the main body 22 of the seal 21 comprises a material that is both resilient and optically transmissive, such as a translucent silicone material. One possible material is disclosed in JP-A-2008291 124, in the context of a light conductive plate for illuminating the keypad of a mobile phone. The fins 23 need not be optically transmissive and may be made of a different material selected for resilience, for example.

[0073] The seal 21 may be a preformed seal that is assembled onto the connector 3, alternatively, the seal may be formed in the gap between the connector 3 and the sub-base 19, for example using a liquid sealant that sets within the gap. Alternatively, the seal 21 could be formed as part of the sidewall of the connector 3, such as a twin-shot seal.

[0074] The main moulding of the connector 3 includes one or more light emitter/receiver housings 32, each of which may hold a respective light emitting and/or receiving device 31, such as an LED or a photosensor. The wavelength of light that is transmitted and received may be in the visible range, or infrared for example. The wires of the or each device 31 are preferably held in place by wire supports 34 forming part of the main moulding. The wires are connected to the vessel controller 15.

[0075] As best shown in Figure 3b, the cordless connector 3 also includes live, neutral and earth terminals for connection to the element power control 18 and/or directly to the heating element.

[0076] The cordless connector 3 may be provided as a discrete component together with the seal 21 and optionally with the device(s) 31, for assembly into any suitable form of sub-base 19.

[0077] The cordless connector 4 of the power base 2 will now be described in more detail with reference to Figures 4a, 4b and 5. The cordless connector 4 includes an outer moulding 53 that fits within the cordless connector 3 of the vessel body 1. The live and neutral terminals of the cordless connector 4 are protected by a shutter seal 54 that is displaced by the cordless connector 3.

[0078] The cordless connector 4 includes an annular light transmitter 41 that is fitted onto an outer moulding 53, for example by means of corresponding click or bayonet fittings 43, 56. The annular light transmitter 41 is made from optically transparent or translucent material. Light emitting and/or receiving optical devices 31 are received in pockets or housings 42 in the annular light transmitter 41, to ensure good optical coupling between the devices 31 and the annular light transmitter 41. The housings 42 extend through apertures 55 in the outer moulding 53 and the devices 31 are held in place against housing abutments 57 in the outer moulding 53 when the light transmitter 41 is fitted onto the outer moulding 53. A seal 44 is also held between the annular light transmitter 41 and the outer moulding 53, to prevent liquid ingress to the devices 31. The seal 44 in this case is not arranged to conduct light between the devices 31 and the light transmitter 41.

[0079] In an alternative embodiment, the annular light transmitter 41 may be integrated with the outer moulding 53, for example by means of a twin shot process, or the outer moulding may be substantially or entirely composed of optically transmissive material.

10080] When the cordless connectors 3 and 4 are connected together as shown in Figure 5, light is conducted between the devices 31 of the power base 2 and of the vessel body 1 through the seal 21 and the annular light transmitter 41, regardless of the relative rotation of the cordless connectors 3 and 4. Precise alignment is not required between the optical devices 31 of the power base 2 and of the vessel body 1, because the seal 21 and/or the annular light transmitter 41 act as light guides or diffusers.

[0081] In order to provide a 360° optical coupling, it is not essential that both the optical connections on the power base 2 and the vessel body 1 subtend 360°; only one or neither of the connections may do so, provided that there is always some optical coupling between them, for example as a result of overlap between them. For example, in an alternative embodiment, each of the three emitters acting through the seal 21 in the appliance may have an effective range or spread of 120° in which case the sensor 31 in the base 2 can be positioned at any point beneath the seal 21, and there would be no need for an annular light transmitter 411 in the base 2.

[0082] In other embodiments, in which there are an equal number of symmetrically positioned transmitters 31 and receivers 31, for example three sensors 31 separated by 1200, there will be a relative rotational position at which each receiver 31 is at the point of weakest transmission. This can be alleviated by positioning one set of receivers 31 or transmitters 31 asymmetrically, such as three separated by 70° such that there is a spacing of 220° between the outside ones, so that at least one of the corresponding sensors is opposite to a hotspot' where the transmitted signal is enhanced. In this case the appliance control 15 or base control 10 may be programmed to search for the strongest signal received. This arrangement may work equally well with any number of sensors 31 and also with single or two-way communication.

100831 In other embodiments additional optical receivers 31 or transmitters 31 may be installed in the vessel body 1 or particularly the base 2 to provide redundancy in case, for example, one of the devices 31 is damaged.

[0084] Figure 6 shows a variant of the cordless connector 3 of the vessel body 1, in which the seal 21 includes a pocket 24 into which the optical device 31 fits, so as to improve the optical coupling between the device 31 and the seal 21.

[0085] Figure 7 shows another variant of the cordless connector 3 of the vessel body 1, in which an annular light transmitter 46 is disposed between the optical device 31 and the main body 22 of the seal 21, so as to improve the optical coupling between the device 31 and the main body 22 of the seal 21. The annular light transmitter 46 has a housing 45 into which the optical device 31 fits, so as to improve the optical coupling between the device 31 and the annular light transmitter 46.

[0086] In each embodiment, the optical device(s) 31 and any housing 45 or pocket 24 therefor may be arranged at an angle to the annular light transmitter 41, 46 or the seal 21 respectively, to improve the optical coupling thereto, or to enhance the light guiding effect of the annular light transmitter 41, 46 or the seal 21 [0087] In the above embodiments, the cordless connectors 3 and 4 could be reversed, so as to be provided respectively in the power base 2 and the vessel body 1. Alternatively, the power base 2 and the vessel body 1 may both have cordless connectors in which a seal is used to provide an optical coupling.

[0088] In an alternative embodiment, a seal other than that around the cordless connector may be used to provide an optical coupling between the power base 2 and the vessel body: for example, a seal between the sub-base 19 and the side wall of the vessel 1.

[0089] As an alternative to optical communication through the seal, the main moulded part of the connectors 3 and 4 may be made of optically transparent material, so as to form an optical coupling therebetween. Hence, as with the optical coupling through the seal, no additional parts are required to provide the optical coupling.

[0090] Some of the light generated by the optical device(s) 31 may be diffused in such a way as to be visible to the user when the vessel 1 is connected to the power base 2, for example to indicate to the user that optical communication is taking place, or for aesthetic effect.

Safety Lid [0091] Figures 8a to 8e illustrate a spill-inhibiting safety feature in an embodiment of the invention, in a twin wall cordless electric keffle. However, the safety feature is applicable to single wall electric kettles and other liquid heating appliances. All the embodiments of the spill-inhibiting safety feature are shown within a removable or openable lid assembly but are equally applicable in portable liquid heating appliances without removable lids.

[0092] In some embodiments the lid assembly may include a complete pouring mechanism so that the vessel body 1 in which it is installed would not require a spout, which may advantageously improve the sealing of the lid into the vessel.

[0093] As shown in Figure 8a, the lid 8 comprises a lid chamber 71, the floor of which comprises a lower lid surface 66 that is removably sealed against the upper end of the reservoir 5 by a reservoir seal 63. The lid 8 including the lid chamber 71 can be removed from the reservoir 5, to allow filling or cleaning of the reservoir 5. Alternatively or additionally the lid 8 may be attached to the vessel body 1 by a hinge.

[0094] The lid chamber 71 acts as a passage for liquid from the reservoir 5, which enters the lid chamber 71 through an aperture 86 in the lower lid surface 66. Liquid may then be poured out from the lid chamber 71 through the spout 7. Optionally, a spout filter 65 is arranged between the lid chamber 71 and the spout 7. Optionally the reservoir 5 can be filled through the spout 7. Optionally, there may be a flap (not shown) arranged in the spout 7 to assist with heat retention; the flap may open both inwardly and outwardly to allow filling and pouring. The flap may also be arranged to be opened by the user operated actuator 75.

[0095] The lid chamber 71 also acts as a passage for steam from the reservoir 5. When liquid boils in the reservoir 5, steam passes through the aperture 86 into the lid chamber 71.

Some of the steam then passes through a steam tube 70 from the lid chamber 71 to a steam-sensitive control 60 arranged to switch off or reduce heating when steam is detected. In this case, the control 60 is an integrated cordless connector and control. The steam sensitive control 60 may include a thermally sensitive actuator, such as a snap-acting bimetallic actuator, onto which steam is directed from the steam tube 70 when the liquid in the reservoir 5 boils. The outer surface of the steam tube 70 is removably sealed against the lower lid surface 66 by a seal 67.

[0096] Alternatively, the steam-sensitive control 60 may be mounted in or adjacent to the lid chamber 71, in which case no steam tube 70 is necessary, but a connection of some type then needs to be made from the control 60 to the heater.

10097] In this specific embodiment, the vessel body 1 has an outer wall 61 spaced apart from an inner wall 62, the latter forming the wall of the reservoir 5. The steam tube 70 passes through the space between the inner wall 62 and the outer wall 61, for example as described and claimed in the applicant's granted patents GB-B-2365752 and CN-C-1239 116.

[0098] The flow of liquid and steam through the aperture 86 is governed by flow management means 80, embodiments of which are described in detail below. The flow management means 80 allows steam to escape from the reservoir 5, but prevents liquid from escaping from the reservoir 5 when the vessel body 1 is tipped over. In at least some embodiments, the flow management means 80 allows liquid to escape from the reservoir S when actuated by a user-operable actuator 75 that is normally biased away from the flow management means 80. The user-operable actuator 75 may be a spring-biased pusher rod slidably mounted in the handle 9, and projecting beyond the handle 9 to present a portion for pushing by the user so as to engage the flow management means 80. Alternatively, the user actuable portion of the actuator 75 may be arranged to be pulled so that another part of the actuator 75 engages the flow management means. The user-actuable portion may be connected to the engaging portion by one or more gears. The user-actuable portion may comprise a trigger.

[0099] A first embodiment of the flow management means 80 is illustrated in Figures 8b-8e.

Figures 8b-8e also show the sealing arrangement between the outer wall 61 and inner wall 62 by means of seal 64 and between lower lid surface 66 and inner wall 62 by seal 63.

[00100] At the upper side of the aperture 86 is located an upper lid sealing face 82, forming a valve seat in which sits an upper part 89 of a valve member 81, having an upper valve sealing face 83 which seals against the upper lid sealing face 82. Both the upper lid sealing face 82 and the upper valve sealing face 83 are upwardly diverging frustums, and preferably conical frustums so that the valve member 81 may be positioned in the aperture 86 with any azimuthal orientation; other shapes such as pyramidal frustums may be used, however. The lower lid sealing face 82 diverges upwardly at a greater angle than the upper valve sealing face 83, so that in the rest position of Figure 8b, with the lower lid surface 66 horizontal, the upper lid sealing face 82 seals against the upper valve sealing face 83 only at the lower ends thereof [00101] In the rest position of Figure 8b, the aperture 86 is substantially closed, to prevent thermal losses through the aperture 86. Optionally, one or more ventilation apertures 87 may be located between the upper lid sealing face 82 and the floor 66, to allow pressure equalization between the reservoir 5 and the lid chamber 71.

[00102] The valve member 81 has a lower part 90 that extends below the aperture 86 and has an upwardly facing lower valve sealing face 85 for sealing against a lower lid sealing face 84, as will be described below. The lower part 90 in this embodiment has the form of an inverted shallow cup or dome.

[00103] In the boiling position of Figure 8c, liquid steam pressure in the reservoir 5 lifts the valve member 81 SO that upper valve sealing face 83 moves apart from upper lid sealing face 82 and allows steam to escape into the lid chamber 71 and thence through the spout 7 or steam tube 70. The steam pressure is insufficient to bring the lower valve sealing face 85 into contact with the lower lid sealing face 84.

[00104] Tn the pouring position of Figure 8d, the upper valve part 89 tends to pivot about a contact point A on the upper lid sealing face 82. However, the user actuates the actuator 75 so as to limit to movement of the upper valve part 89 SO that the upper and lower valve sealing faces 83, 85 seal against the respective upper and lower lid sealing faces 82, 84 at one side only, leaving a crescent-shaped passage for the liquid to pass the valve member 81 at the other side.

[00105] If the vessel body 1 is tipped without the actuator 75 being actuated, as shown in Figure 8e, the valve member 81 rotates so that the upper valve sealing face 83 lies flat against the upper lid sealing face 82, on the side towards which the vessel body 1 is tipped. This brings the lower valve sealing face 85 completely into contact with the lower lid sealing face 84, thus sealing the aperture 86 and preventing spillage of liquid therethrough. In other words, the valve member 81 acts as an overcentre mechanism that closes the valve if tipped.

[00106] The lower valve part 90, though wider than the aperture 86, may be sufficiently flexible to be forced through the aperture 86 if steam pressure builds up sufficiently, thus releasing the pressure. Tn this way, the valve member 81 acts as a safety valve. However, as an alternative or additional feature, a separate pressure relief valve may be provided in the lower lid surface 66, for relieving excess pressure in the reservoir 5 into the lid chamber 71. In either case and in other embodiments, it may be advantageous to provide some means for directing steam and/or liquid exhausted through the pressure relief valve away from the spout 7, for example by means of a baffle or shroud in the lid area, or the pressure relief valve may exhaust via the steam tube 70 to the control 60. The means for directing exhausted steam and/or liquid may form part of the valve member 81, and may be formed by the shape of the lower valve part 90 and/or the aperture 86.

[00107] The ability to pass the lower valve part 90 through the aperture 86 also allows easy fitting and replacement of the valve member 81. Alternatively, the upper and lower valve parts 89, 90 may be fitted or clicked together from either side of the aperture 86 to facilitate assembly.

[00108] In the specific embodiment, the aperture 86 is positioned towards the spout 7, while the steam tube 70 is positioned away from the spout 7 and opens towards the upper part of the lid chamber 71, as described and claimed in the applicant's granted patent GB-B- 2332095. As a result, any liquid leaking through the aperture 86 will tend not to enter the steam tube 70 if the vessel body 1 is knocked over and lies on one side, resting on the handle 9 or spout 7. This is because either the steam tube 70 or the spout 7 will be above a horizontal plane through the centre of the vessel body. Furthermore the hollow lid assembly 150 may act as an additional reservoir for any liquid that enters through the aperture 86 before the liquid level reaches the steam tube 70.

[00109] An alternative embodiment of the flow management means 80 is shown in Figures 9a to 9c. In this embodiment, the upper valve part 89 is connected through the aperture 86 to the lower valve part 90 by a pivoting joint 88, which is preferably a universal joint enabling the upper valve part 89 to pivot about any horizontal axis. The lower valve part 89 is constrained to move perpendicularly to the lower lid surface 66 by guides 91.

[00110] In the boiling position as shown in Figure 9a, as in the embodiment of Figure 8c, upper valve sealing face 83 moves apart from upper lid sealing face 82 and allows steam to escape into the lid chamber 71.

[00111] In the pouring position of Figure 9b, the upper valve part 89 pivots about a contact point B on the upper lid sealing face 82, on a side opposite to the actuator 75.

However, the actuator 75 limits the extent to which the upper valve part 89 can rise up and thereby lift the lower valve part 90, so that liquid is able to flow around the lower valve part 90 and the upper valve part 89, through the aperture 86.

[00112] In the tipped position of Figure 9c, the upper valve part 89 is not constrained by the actuator 75, which is not actuated and is biased away from the valve member 91. The upper valve part 89 is able to pivot further about the contact point B, thereby lifting the lower valve part 90 so that the lower valve sealing face 85 seals against the lower lid sealing face 84 and closes the aperture 86, thus preventing leakage of liquid.

[00113] Another alternative embodiment of the flow management means 80 is shown in Figures lOa to lOc, which show respectively the boiling, pouring and tipped positions. In this embodiment, the upper valve part 89 and lower valve part 90 are spherical, but the valve member 91 functions similarly to that of the embodiment of Figures 8a to 8e. The upper and lower valve parts 89 and 90 may be joined by a universal joint as illustrated in the embodiment of Figures 9a to 9c.

[00114] Figure ha shows an alternative embodiment in which the lid chamber 71 may be separated into a front chamber 94 and a back chamber 95, as shown in more detail in Figure 1 ib, and/or may include a venting arrangement as shown in Figures 1 ic and lid, or Figures lie and 1 if, or Figures 1 lg and 1 lh, or Figures lii, 1 ij and ilk, or Figures 111 and lim.

[001151 As shown in more detail in Figure 1 ib, the front chamber 94 includes the aperture 86, which in this embodiment is used for dispensing liquid from the reservoir 5.

Steam and/or air are vented through a steam vent 92 in the lower lid surface 66, into the back chamber 95. The front chamber 94 is thermally insulated from the back chamber 95 by a moveable flap 93 that is normally closed, but opens under sufficient pressure from steam in the back chamber 95, to release the steam pressure into the front chamber 94 and through the spout 7. This embodiment is particularly suited to filling through the spout 7, as the flap 93 would help prevent the liquid entering the back chamber 95. In alternative embodiments with a separate pressure relief valve (for example pressure relief 170 below), the partition between the front chamber 94 and the back chamber 95 may be fixed, in which case the pressure relief valve may exhaust via the steam tube 70 to the control 60.

[00116] The aperture 86 is normally closed by the actuator 75, which in this embodiment is biased towards the spout 7. When a trigger 99 is pulled by the user, the actuator 75 is pulled back towards the handle 9 and opens the aperture 86 to allow pouring through the spout 7. The actuator 75 may be slidably mounted in the lid chamber 7, for example by means of one or more slots in the lower lid surface 66, so as to make a seal against the lower lid surface. If the vessel body 1 is tipped over, liquid is substantially prevented from leaking through the aperture 86 by the sealing of the actuator 75 against the lower lid surface 66.

[001171 In the venting arrangement of Figures ii c and lid, the steam vent 92 is always open, even when the actuator 75 is pulled back. Hence, the steam vent 92 allows air to enter the reservoir 5 as liquid is poured out, thereby equalising the pressure within the reservoir 5. If the vessel body 1 is tipped over, liquid may leak from the reservoir 5 into the back chamber 95 but may be partially retained within the back chamber 95. If liquid enters the steam tube 70, it can be drained away from a steam sensor by the use of a steam chamber as disclosed for example in the applicant's granted UK patent GB-B-23 18452 and its Chinese equivalent CN-C-1149046.

[00118] Tn the alternative venting arrangement of Figures lie and hf, the steam vent 92 has an aperture seal 96, for example comprising silicone flaps, that opens under steam pressure from within the reservoir 5 and seals when the steam pressure is reduced. When the vessel body 1 is tipped over, the aperture seal 96 inhibits leakage of liquid through the steam vent 92. The aperture seal 96 will also open inwardly to equalise pressure as the interior of the reservoir 5 cools, and may allow pressure equalisation during pouring.

[00119] In the further alternative venting arrangement of Figure hg and 1 lh, the steam vent 92 has an aperture flap 97 that opens under steam pressure from within the reservoir 5 and seals when the steam pressure is reduced. The aperture flap 97 allows pressure equalisation during cooling of the reservoir 5 and pouring, but may only be partially effective in preventing liquid leakage when the vessel body 1 is tipped over.

[00120] In the further alternative venting arrangement of Figures lii to ilk, the steam vent 92 is closed by a valve arrangement in a similar manner to the embodiment of Figures lOa to lOc. The actuator 75, in the pulled back position of Figure hlj, prevents the valve member 81 from rising up, and therefore prevents the lower valve part 90 from sealing completely against the lower lid sealing face 84. Alternatively, a valve arrangement as disclosed in Figures 9a to 9c or 8b to 8e may be used.

[00121] In a further alternative venting arrangement shown in Figures 111 and 1 im, a conical valve member 98 is seated against a lower lid sealing face 84 when the vessel body 1 is horizontal. Steam pressure forces the valve member 98 upwardly so as to release steam pressure through the steam vent 92. When the vessel body is tipped, as shown in Figure 11 m, the upper face of the valve member 98 seals against the steam vent 92 and thereby prevents liquid leakage. One or more small, permanently open vents may be provided around the steam vent 92, to allow a degree of permanent venting.

[00122] Figures 12a to 12d show a further embodiment of the invention, in which a steam path is integrated within a hollow moulding 100 of the actuator 75. The steam tube 70 is in communication with the hollow interior of the moulding 100, with a cap 101 also forming part of the moulding 100. The moulding 100 includes one or more vents 102 at an end towards the handle 9.

[00123] In the rest position of the actuator 75, the aperture 86 is connected to the hollow interior 100, so that steam escaping from the aperture 86 passes into the steam tube or through the vents 102. If the vessel body 1 is tipped over, liquid will flow through the vents 102 into the lid chamber 71 and may escape through the spout 7. However, if the vessel body 1 lies on its side, then either the vents 102 or the spout 7 are raised above the plane of symmetry of the vessel body 1, thereby restricting the volume of leakage.

[00124] When the user actuates the actuator 75 by pulling the trigger 99, the aperture 86 is opened to the lid chamber 71, allowing liquid to be poured out through the spout 7.

[00125] Figures 13a to 13d show a further embodiment of the invention, in which the aperture 86 acts as an outlet for both liquid and steam, and includes a valve arrangement similar to that of Figures 111 and urn. In this embodiment, no user actuation is required to allow pouring. Instead, the valve seat includes an inwardly projecting portion 103 located towards the spout side of a lower lid valve wall 104, which prevents the conical valve member 98 from sliding upwards and closing the aperture 86 when the vessel body 1 is tipped forwards for pouring. However, if the vessel body 1 is tipped forward suddenly, the valve member 98 will jump past the projecting portion 103 and seal against the upper lid sealing face 82. Tf the vessel body 1 is tipped sideways or backwards, the valve member 98 will not be engaged by the projecting portion 103 but will seal against the upper lid sealing face 82, thereby closing the aperture 86. At the upper end of the lower lid valve wall 104 are provided one or more venting slots 87, which allow venting of the reservoir 5 when the valve member 98 is in its rest position, towards the bottom of the lower lid valve wall 104.

For improved thermal insulation, the spout 7 may include a spout flap (not shown) that opens when the vessel body 1 is tipped forward for pouring; additionally the spout flap may open inwards to allow filling via the spout 7.

[00126] Figures 13e to 13g show an alternative embodiment of the valve arrangement, in which the inwardly projecting portion is located towards the lower end of the wall 104, and engages with a circumferential groove 105 towards the lower end of the valve member 98.

[00127] In each of the previously described flow management and venting arrangements, surfaces to be sealed may have their sealing properties improved by one or both of the surfaces including a localised portion or layer of sealing material, for example a silicone or rubber compound.

[00128] Figure 14a shows an exploded view of a lid 8 comprising a lid chamber 71, in another embodiment. The lid 8 comprises an inner lid moulding 158 which has an aperture 86 through the lower lid surface 66, an aperture 155 in a side that cooperates with the spout (not shown), and a projecting portion 156 that acts as a spout baffle. A top lid portion 157 covers the inner lid moulding 158 and the baffle 156.

[00129] Within the inner lid moulding 158, a pendulum 159 is pivotally mounted about a substantially vertical axis Y-Y, and supported by pendulum supports 154. The pendulum 159 is acted on from opposite sides by respective springs 151 so as to centre the pendulum 159 when the vessel body I is upright or tipped forward towards the spout 7. The force of the springs 151 is sufficient to overcome any friction between the pendulum 159 and the pendulum supports 154 so that the pendulum 159 is in equilibrium. A central recess 160 in the pendulum 159 allows liquid through the aperture 86 into the lid chamber 71, and subsequently through the aperture 155 into the spout 7, when the vessel body 1 is tipped towards the spout 7 for pouring.

[00130] Tn other embodiments where for example the pendulum 159 is moulded in plastic, metal or other resilient material, then the pendulum 159 may incorporate the springs 151 as part of the moulding of the pendulum 159. The springs 151 may be coil springs. Tn other embodiments the springs 151 may be bistable so that the pendulum 159 resists small forces but reacts quickly to larger forces.

[00131] As in the previous embodiments, the lid 8 may be hinged or removed for filling the reservoir 5 and fitted or locked into place for the liquid heating process.

[00132] Figure 14b shows the lid 8 in the pouring position. The force of the liquid may centre the pendulum 159 around the aperture 86 if the vessel body 1 is tipped at a slight angle to one side. The recess 160 or the aperture 86 may be shaped or dimensioned to facilitate this effect.

[00133] As shown in Figure 14c, if the vessel body 1 including the lid 8 is tipped over, then the pendulum 159 rotates so that the central recess 160 is not aligned with the aperture 86 and the front part of the pendulum 159 covers and seals against the upper lid sealing face 82. Hence, in this embodiment the pendulum 159 acts as a valve. The weight of the pendulum 159 is sufficient to overcome the upward spring force of the spring 151, shown as arrow X. Dependent upon the material of the pendulum 159, additional weights (not shown) may need to be added to the pendulum 159 to achieve this effect.

[00134] The pendulum 159 may incorporate a built-in filter above or around the front part to filter liquid as it is poured out. Either the filter or the pendulum 159 may be arranged to be removable easily for cleaning.

[00135] When the vessel body 1 is replaced upright or tipped forward towards the spout 7, then the forces of the springs 151 will be sufficient to return the pendulum 159 back to the centre position of equilibrium.

[00136] The pendulum 159 is symmetrical about a plane passing through the pivotal axis Y-Y and the central recess 160, so acts to seal the aperture 86 irrespective of which side the vessel body 1 falls onto.

[00137] The pendulum 159 may be slidably held against the aperture 86 to enhance the sealing effect, for example by a slot or groove to one or both sides of the aperture 86.

[00138] Figure iSa show an exploded view of a lid 8 comprising a lid chamber 71, in another embodiment. The assembly includes a pendulum 159 and springs 151 as in the embodiment of Figures 14a-c, but the pendulum 159 cooperates with a conical valve 98.

The conical valve 98 is similar to that shown in Figures 111 and 11 m, but is prevented from closing in a pouring configuration by interaction with the pendulum 159, in a manner similar to the actuator 75 in the embodiments of Figures 8a to lOc and lii to ilk, but without the need for user actuation.

[00139] The radially outer end of the pendulum 159 includes a cross member 161 extending at a low level across a central recess 160. The conical valve 98 includes an upwardly extending portion 98a that extends through the aperture 86. When the vessel body 1 is in the pouring position as shown in Figure 15c, the cross member 161 abuts the upwardly extending portion 98a and prevents the valve 98 from lifting fully, so that liquid can pass through the aperture 86 and central recess 160 into the spout 7.

[00140] The radially outer end of the pendulum 159 includes a ramp portion 163 at either side of the central recess 160 which lead onto raised portions 162. if the vessel body 1 is tipped over as shown in Figure 15d, then the pendulum 159 rotates so that either of the raised portions 162 is positioned above the valve 98, and do not restrict the upwardly extending portion 98a, so that the valve 98 can rise up and seal the aperture 86.

[00141] Tt can be seen that the pendulum 159 acts in a similar manner to the actuator 75, but the function of restricting the valve 98 whilst pouring is carried out automatically rather than by the user. In this embodiment, the upwardly extending portion 98a is narrow so that the liquid is less restricted, and the upwardly extending portion 98a does not include a sealing face. However, any of the valves disclosed in Figures 8a to lOc and lii to ilk may be modified to interface with the pendulum 159 rather than the user actuator 75.

[00142] In a variant of embodiment of Figures iSa to 15d, the pendulum supports 154 may form camming surfaces that rise up at either side of the equilibrium position, so that the distance between the pendulum 159 and the lower lid surface 66 increases as the pendulum 159 rotates away from the equilibrium position. In this case, the radially outer end of the pendulum 159 may have a lower profile. The embodiments of Figures 14 and 15 may include means in the lid 8 to centre the pendulum 159 when the lid 8 is placed on the reservoir 5, so that the aperture 86 is opened and pressure caused by placing the lid 8 on the reservoir 5 is released. However in some instances the appliance may be energised whilst the vessel body I is tipped over, or the user does not take the lid 8 off before re-energisation, so that some form of venting or pressure relief will be necessary.

[00143] Figures 16a and 16b show an additional venting feature that may be applied to the embodiments of Figures 14 and 15, in which the pendulum 159 blocks one or more vents when the aperture 86 is open, for example in pouring configuration, and opens the one or more vents when the aperture 86 is sealed, for example when the vessel body 1 is tipped to one side.

[00144] Tn this embodiment, the lower lid surface 66 has two vents 165 that open into the reservoir 5. An extension 167 of the pendulum 159 covers the vents 165 when the aperture 86 is exposed. However, when the vessel body 1 is tipped over one or the other of the vents 165 are exposed through a corresponding of the apertures 166 in the pendulum extension 167. This arrangement is particularly advantageous as the vent 165 that is exposed is higher than the centre plane of the vessel body 1 when tipped on one side, so that the risk of leakage is reduced and may be avoided altogether if the kettle is overfilled. Figure 16a shows one of the vents 165 and 166 corresponding when the appliance is tipped; in an alternative embodiment both the vents 165 could be covered by the pendulum 159 and then one or other may become completely exposed as the pendulum rotates.

[00145] Figures 17 to 19b show a further embodiment that differs from that of Figures 16a and 16b in that the pendulum 159 is suspended below the lower lid surface 66.

This is advantageous in that when the vessel body 1 is tipped over, the pressure of the liquid within the vessel body 1 acts to push the pendulum 159 against the lid base 66 so as to improve the liquid sealing capabilities. An additional sub base 164 may be placed beneath the pendulum 159 which supports the pendulum 159 against the lid base 66 and also protects the mechanism, for example the springs 151, from damage when the lid assembly is removed from the vessel body 1. The pendulum 159 may include small pips' or protrusions on the underside to reduce friction against the sub base 164. Alternatively the pendulum 159 or sub base 164 may include a camming means so that the pendulum 159 is free to rotate until it reaches the extreme of movement. The sub base 164 may be manufactured in a material, such as stainless steel, that will capable of constant use above boiling liquid with the minimum of distortion. The sub base 164 preferably incorporates apertures 171 and 172 that correspond with the apertures 86, 165 and 166 in the sub base 66 and the pendulum 159. The aperture 171 may include a mesh or filter.

[00146] This embodiment may also include a steam path moulding 100 as described in previous embodiments and may also include a flap 93 or moulding (not shown) so that the front chamber 94 and the back chamber 95 are partitioned.

[00147] The steam path moulding 100 may be formed as a separate moulding and/or may be part of the lid inner moulding 158 or the lid cover moulding 157.

[00148] Figures 18a and 18b show how the pouring, ventilation, steam path and pressure relief aspects are achieved in this embodiment. Figures 19a and 19b are corresponding isometric cut-away views.

[00149] Figure 1 8a illustrates the lid assembly 150 in the heating and pouring mode (seen from below, with the sub base 164 removed). The pendulum 159 is recessed so that the front part of the aperture 86 is not restricted. Furthermore the apertures 165 and 166 in the lid base 66 and the pendulum 159 are lined up in the position shown in this Figure so that they act to allow steam into the rear part of the steam path moulding 100 and they also allow pressure to equalise in reservoir 5 when the vessel body 1 is in the filling or pouring mode. In the case that the steam moulding 100 is partitioned, then one or more of the apertures 165 may be positioned towards the rear of the steam path moulding 100.

[00150] Figure 18b illustrates the lid assembly 150 in tipped mode (seen from below, with the sub base 164 removed) when the vessel body 1 is laid on its side. The pendulum 159 has rotated so that it now covers the aperture 86. For safety purposes, the pendulum 159 incorporates two pressure relief valves 170 so that, whichever side the appliance is tipped, one of the pressure relief valves 170 is positioned above the rear part of the aperture 86, thus ensuring the reservoir 5 can be vented if for example the element 12 continues to heat the liquid after the vessel body 1 has tipped over. n this embodiment the pressure relief valves 170 are illustrated as self-sealing diaphragms, but any pressure relief valve including those already described may be employed. In other embodiments the pressure relief valve(s) 170 could be situated directly in the lid base 66 as previously described. If this were the case then the lid sub base 164 would require corresponding apertures.

[00151] Figure 20a and 20b show a further embodiment in which a single spring 151 acts on the pendulum 159. The pendulum 159 is positioned over a boss 153 on the lid bottom moulding 291. One end of the rear part of the spring 151 incorporates a flat sided aperture which sits over a corresponding flat at the end of the boss 153. The spring 151 may include a twist at the point 290 so that the plane of the front part of the spring 151 is 90° to the plane of the rear part, so the front part can be positioned in a corresponding slot 286 in the pendulum. Alternatively the spring 151 may have a flat profile and be keyed in an upright position into the boss 153.

[00152] The pendulum and spring assembly is secured by a screw 297 and washer 285 tightened against the boss 153. The pendulum 159 is then free to rotate about the boss 153 when the kettle is tipped over and the spring bias will return the pendulum 159 to the centre position when the kettle is upright. An optional spacer 287 may be incorporated between the pendulum 159 and the washer 285. The apertures 86, 165 and 293 in the lid bottom moulding 291 have raised edges to provide a flat surface for sealing. The raised portions around the apertures 86, 165 and 293 along with raised portions between the apertures also help to reduce the friction between the pendulum 159 and the lid 291.

[00153] The lid assembly consisting of a lid cover 157, lid inner moulding 158, steam guide 100, lid bottom moulding/pendulum subassembly and an (optional) sub base 164 may be clamped together with screws 288 or other suitable clamping means. Each of the mouldings may include spacer bosses for example 282 to provide further integrity to the lid assembly. Each of the functional plastic parts may be separate mouldings or may be integral with adjacent mouldings for example the lid cover 157 and the steam guide 100 may be all part of one moulding. During the assembly a near water tight seal is achieved between the steam moulding 100 and the bottom lid moulding 291 which may form one or more isolated or segregated chambers 294 within in the lid assembly. The lid assembly is attached to the hinge support 296 and as with previous embodiments the whole assembly including an optional seal 64 can then be placed onto a suitable vessel of any material for example, plastic, glass, ceramic or stainless steel. Tn this embodiment the spout (not shown) is formed within the vessel, however as with previous alternative embodiments the spout may be formed as part of one of the lid assembly mouldings, for example the sub base 164, or alternatively as a separate moulding or part and clamped into position during the lid assembly procedure.

[00154j This embodiment differs over previous embodiments in the manner in which the steam and liquid is managed.

[00155] Figure 20b shows a cut away view of the lid assembly in the boiling and pouring position without the sub base 164. The pendulum is centralised, which allows liquid to pour through the aperture 86. Apertures 165 and 166 are also aligned to vent into the steam path moulding 100. The aligned apertures 165 and 166 may be separated by a feature for example a partition moulding 295 or a flap 93 (not shown) so that the rear portion 95 acts to provide steam to the steam sensor and both sets of apertures act to provide pressure equalisation in the vessel when pouring. The moulding 295 may provide complete or partial segregation so as to minimise water from the spout area entering the rear portion 95. Any water that does enter the rear portion of 95 will subsequently drain through aperture 165 into the vessel. The rear portion 95 may also include additional features to prevent any water that enters this area from entering the steam tube (not shown).

[00156] In a tipped position the pendulum, which may be weighted, rotates and covers the apertures 86, 165 and the lower of the two apertures 293. It is expected that, providing the kettle is not overfilled, the higher of the two apertures 293 will be above the level of the water when the vessel is on its side. Any water that does splash out of the aperture 293 will be contained in the segregated areas 294. This segregated area will also act to contain additional boiling water (after boil) and steam that may be emitted through the aperture 293 during or shortly after the appliance has been overturned. Any water that does enter the segregated area 294 will subsequently drain through aperture 293 into the vessel when the vessel is up righted.

[00157] The optional sub base 164 includes apertures 171, 172, 292 for venting and pouring and may include apertures 284 for screw attachment.

[00158] As with previous embodiments the lid assembly need not incorporate a hinge, furthermore in all embodiments the lid assembly can be appropriately shaped to suit the vessel aperture.

[00159] As a further feature of the embodiments of Figures 14 to 20, the springs 151 may be arranged to bias the pendulum 159 to one side of the centre line when the vessel body 1 is in an upright position, thereby closing the aperture 86, for greater thermal efficiency. In the embodiment of Figure 16, the reservoir 5 would then be vented through one of the vents 165. When the vessel body 1 is tipped forward towards the spout 7, the gravitational force on the pendulum 159 overcomes the bias of the springs 151 so that the aperture 86 is uncovered, thereby allowing liquid to be poured out.

[00160] In an alternative embodiment, the pivoting pendulum 159 is replaced by a member that slides from one side to another under gravity, but is biased towards a central equilibrium position by springs 151. In this case, the sliding member may uncover an upper one of the vents 165 as it slides downwards.

1001611 In each of the previously described pendulum arrangements, surfaces to be sealed may have their sealing properties improved by one or both of the surfaces including a localised portion or layer of sealing material, for example a silicone or rubber compound.

[00162] Furthermore each of the previously described embodiments may include an alarm to warn the user that the vessel body 1 has tipped over. In its simplest form this alarm may cooperate mechanically with the pendulum 159, such as a bell. Alternatively, the alarm may be an electronic or electromechanical warning system triggered by the flow management mechanism 80 or a tilt switch and powered by a battery or capacitor.

[00163] Alternatively or additionally, each of the previously described embodiments may include a switch that disconnects power to the heater 12 and/or other electrically powered components when the vessel body 1 is tipped over.

100164] Tn each of the embodiments having the pendulum 159 or its equivalent, there may be provided means to lock the pendulum 159 in its closed valve position, the lock being releasable by user actuation, for example of the actuator 75. In this way, the valve stays securely closed as the vessel body 1 is picked up after being tipped over, until the user needs to fill or pour from the vessel body 1.

[00165] In all the embodiments the relationship between the lid assembly 150, the spout 7 and the flow management means 80 and 159 may assist in preventing liquid splashing out of the spout 7 as the liquid boils, thus allowing for the height of the vessel body 1 to be reduced.

[00166] In other embodiments the flow management means 80 may be positioned within the spout, which may assist in reducing the overall height of the vessel body 1.

Removable Lid Assembly 1001671 The concept of a removable and/or replaceable lid assembly that incorporates a hinged lid and optionally a spout and/or filter is in itself novel and can be incorporated with or without the safety lid mechanism into many vessel types. This arrangement is particularly suitable for vessels in which, for various reasons, push fit lids are employed, for example, stainless steel kettles or for vessels where spouts are difficult to form, for example glass: in which case the whole lid assembly may be a watertight (but removable) fit and the opening lid part is, for example, more convenient for filling. The lid assembly may include seals, latches and catches for attaching onto the vessel and the lid part may incorporate any of the standard or proprietary lid opening mechanisms including sprung and slow acting mechanisms.

1001681 The ability to remove the complete hinged lid assembly would also be particularly useful for vessels that require access for example for internal cleaning or for example vessels that are to be placed upside down for drainage or for placing in a dishwasher.

[001691 Figures 21a, 21b and 22 illustrate specific waterproof appliance embodiments in which a removable hinged lid assembly 150 is incorporated, the removable assembly incorporating the hinge.

[001701 Figure 21a illustrates a cross section of water proof stainless steel kettle operated from a user interface 11 in the cordless base 2. The hinged lid assembly 150 includes attachment features (not shown) to secure the assembly onto the vessel body during use and is removable for cleaning purposes. In this embodiment the sealing means 248 remains attached to the vessel 1; however as previously described the sealing means may be a part of the lid assembly 150.

[001711 The lid assembly includes a user actuable lid release 251 and may also include a damping means so the lid opens in a more controlled manner.

[00172] In this embodiment the spout 7 is part of the vessel I but as previously described the spout 7 may be an integral part of the lid assembly 150.

[001731 The cordless connector 3 is sealed into the sub base 243 using Easifix® type sealing means 21 and the sub base 243 is sealed against the inside wall of the vessel 1 with a similar Easifix® type sealing means 242, so that the complete water heating vessel part is waterproof. In other embodiments the vessel body could be plastic, or any suitable material and the components may be sealed into the vessel by alternative sealing means.

[00174] The 3600 cordless connector system 3 and 4 may include optical communication means, for example optical emitter/detector 31 and annular light transmitter 41 as previously described and suitable electronics in the kettle base 6 and cordless base 2 so that the kettle responds to the user interface 11. In this embodiment the water temperature is sensed by a thermistor 249, however the appliance may be controlled by alternative means, for example the previously described Turbulence detection means.

[001751 In other embodiments the communication from the base 2 to the vessel 1 may be via other means for example additional pins on the cordless connector.

[00176] Figure 22 illustrates a waterproof appliance in another embodiment, incorporating the previously described lid assembly 150, in which the user interface 253 is in the vessel part and there is no requirement for communication between the vessel 1 and the base 2.

100177] Tn this embodiment the kettle is controlled by an electro mechanical thermostat 244 positioned in a moulding 252 in the top part of the vessel 1. The moulding 252 has a wet side 252a and a dry side 252b. The sensing part of the thermostat 244 is sealed into the wet side 252a by sealing means 245. The wet side 252a may communicate with the outside of the vessel to assist with air circulation so that the thermostat may reset quicker.

[00178] The user actuator 253 may be part of the lid assembly 150 and interfaces or may be joined onto push rod 246 which in turn interfaces with the thermostat 244. The pushrod 246 is sealed (not shown) as it enters the dry side of the moulding 252b. There may more than one actuator and linkage, for example one for one and one for off 100179] A tube 240 for electrical wiring (not shown) communicates through the element plate 12 into the dry side of the moulding 252a. Alternatively, this tube 240 may be a moulded component. In a double-walled appliance, the wiring could pass between the inner and outer walls.

[00180] In this embodiment there is no requirement for optical communications and the cordless connector 3 is sealed into the sub base 243 using Easifix® type sealing means 21 and the sub base 243 is sealed against the inside wall of the vessel 1 with a similar Easifix® type sealing means 242, 50 that the complete water heating vessel part is waterproof [00181] Alternatively, the thermostat 244 may be positioned in the base 2, or in a recess in the handle 9.

[00182] In both embodiments of Figures 21 and 22, the sub base 243 may be attached to the vessel 1 by screws 241 or by alternative means for example a click fit.

[00183] Additional features and components such as illumination means are preferably sealed so that they can be immersed in water.

[00184] It is preferred that the handle 9 is moulded, for example as a solid part, so that there is no opportunity for water ingress when submerged in water, or as a hollow part with means to allow drainage of water fi-om the interior. The handle 9 may be foldable against the vessel body or removable to allow easier placement into a dishwasher.

[00185] In further embodiments the handle 9 may be manufactured as part of the lid assembly 150 and the whole assembly may be removably attached to the kettle by, for example, a bayonet fix method.

Capacitive Level Sensing [00186] Figures 23a, 23b and 24a-24d illustrate capacitive level sensors for the reservoir 5 of a liquid vessel 1; this may be a liquid heating vessel, but the application of this embodiment is not restricted to liquid heating vessels.

[00187] In the example of Figures 23a and 23b, a single electrically conductive strip is positioned outside the wall of the reservoir, and an electrical connection is made through the electrically conductive element plate 12 at the bottom of the reservoir 5 to the liquid in the reservoir 5, which liquid is itself electrically conductive. The electrically insulating wall of the reservoir 5 then acts as the dielectric in a capacitor in the overlap area between the liquid and the electrically conductive strip.

[00188] However, as shown in Figure 23b, the capacitance of this capacitor varies by as much as 40% when the vessel body 1 is tilted up to 20° forward and backward i.e. away from and towards the strip 110. A tilt of 20° is normal during filling of the vessel, but it is at this time that an indication of fill volume is most needed. Hence, the arrangement with a single strip 110 is not suitable for capacitive detection of fill volume in these circumstances.

[00189] In the embodiment of Figures 24a-24d, the effects of tilt are substantially avoided by having a plurality of conductive strips mutually spaced apart, and measuring the capacitance between conductive strips rather than between the conductive strip 110 and the element plate 12.

[00190] First and second electrically conductive strips 1 lOa, 1 lOb are positioned at opposite sides of the reservoir 5, on the outside of the wall of the reservoir 5. The vessel body 1 advantageously have a double walled construction as in the embodiment of Figure 8a or 1 la for example, in which case the conductive strips 1 lOa, 1 lOb are located on the outside of the inner wall 62 and are protected and/or obscured by the outer wall 61. The use of capacitive level sensing is particularly advantageous for double-walled vessels, since otherwise a liquid window might be needed to view the level within the reservoir 5, which reduces the advantage of thermal insulation of the double walled construction.

[00191] The capacitance is measured between the conductive strips llOa, liOb. The walls of the reservoir 5 are electrically insulating and act as a dielectric, while the liquid within the reservoir 5 acts as an electrical conductor between the walls of the reservoir 5.

Hence, the capacitance between the first and second conductive strips 1 lOa, 1 lOb is that of two capacitances in series: CTotal = (Ci X C2)/(C1 + C2) (1) where C1, C2 are the capacitances between the first and second conductive strips 1 lOa, 1 lOb respectively and the liquid in the reservoir 5, through the dielectric wall.

[00192] The capacitances C1, C2 depend on the liquid level adjacent the corresponding conductive strips llOa, ilOb, as follows: C = CrC0A/d (2) where Cr is the permittivity of free space ( 8.85 x 1012 Fm') c0 is the relative permittivity of the reservoir wall (typically 2.25) d is the thickness of the reservoir wall (typically 2.6 mm) A is the area of overlap between the conductive strip 11 Oa, 11 Ob and the liquid adjacent the conductive strip llOa, liOb within the reservoir 5.

[00193] The variation of capacitance with fill level of a cylindrical reservoir 5 in an example is shown in Figure 24b, in which the reservoir 5 is kept upright. The capacitance increases linearly with fill level, and is proportional to A. [00194] When the vessel body 1 is tilted, as shown in Figure 24c, the liquid level increases at one conductive strip 11 Oa, and decreases at the other conductive strip 11 Ob. The changes in capacitance at each strip 1 lOa, 1 lOb do not cancel out, because the total capacitance is not the sum of the individual capacitances, as shown in equation 1 above.

However, as shown in the example of Figure 24d, the variation of the capacitance due to tilting up to 18° either forwards or backwards is less than 5%, compared to a 40% variation in the case of a single conductive strip.

100195] During filling, the liquid in the reservoir 5 may be turbulent, which can cause further uncertainty in the detected fill level. However, by using two or more conductive strips 11 Oa 11 Oh at different locations, the variations in fill level caused by turbulence are averaged out.

[00196] The detected capacitance may be used to indicate a fill level, either to a control within the vessel body 1 or to a user. The indication may represent a substantially continuously variable fill level, or merely that the fill level has exceeded one or more thresholds.

[00197j A simple oscillator circuit for indicating the fill level as a frequency signal is shown in Figure 25, in which the capacitance C is the total capacitance CTotal of the conductive strips 11 Oa, 11 Ob as given by equation 1 above. The frequency f of the frequency signal is given by f= 1/(RC) (3) where R is the (constant) resistance of the resistor in the oscillator circuit.

The frequency f is inversely proportional to the capacitance C (=CT01a1), from which the fill level can be calculated.

[00198] The frequency signal may be output to a microcontroller or dedicated circuit which calculates and displays or otherwise indicates the fill level, for example as a digital display of the number of cups or volume. Alternatively, the frequency signal f may be amplified and output directly to a speaker, so that the user can judge the fill level from the pitch of the sound.

[00199] Figure 26 shows an alternative circuit in which the capacitance is measured by one or more threshold detectors Dl, D2, providing respective outputs to a microcontroller MC which generates an indication (such as a sound and/or light effect) of the thresholds being exceeded; for example, a low beep or when crossing a low fill level threshold, and a high beep when crossing a high fill level threshold. This arrangement is particularly advantageous when filling a kettle, as the user does not need to watch the level of liquid in the reservoir 5, but simply fills until the relevant indication is given.

[00200] Preferably, the vessel body includes a power supply such as a battery or capacitor, for powering the level sensing circuitry while the vessel body 1 is separated from the base 2 for filling.

User Interface [00201] Figure 27 illustrates an intuitive rotational user interface component 280 for the user interface 11, or for another liquid heating appliance, for example an Eco' kettle as described in WO-A-2008/139173, a flow through heater as described in WO-A- 2008/139205 or a liquid heater as described in PCT/GB2O1O/050135, or any type of coffee or tea maker. The user interface component 180 includes a portion rotatable by a user, preferably comprising an outer portion 181 and an intermediate portion 182. The outer portion 181 may have a knurled edge so that it is easy to turn. Alternatively or additionally, the intermediate portion 182 may be raised to assist rotation. Tn another alternative, the component 180 is not mechanically rotatable, but is sensitive to a rotational actuation by the user; for example, the outer portion 181 and/or intermediate portion 182 may be touch sensitive.

[00202] A centre portion 183 of the user interface component 180 includes an indicator, preferably comprising a liquid temperature indicator 184 and a liquid level indicator 185, 186.

[002031 Rotational actuation of the component 180 is converted, for example by user interface electronics, to control signals for controlling the operation of the liquid heating appliance, particularly the temperature to which the liquid is to be heated and/or the volume of liquid to be heated and/or dispensed. Hence, two parameters may be controlled by a single user actuation. This may be achieved by cycling through each of a plurality of discrete values for the first parameters, and progressively changing the value of the second parameter for each cycle of the first parameter. The selected values of the first and second parameters may be displayed in the centre portion 183.

[00204] Alternatively, a further, distinct user actuation of the component 180 may be used to switch the effect of the rotational actuation between the first and second parameters.

For example, the centre portion 183 may be touch sensitive, such that touching the centre portion switches between adjustment of the first and second parameters. The parameter being adjusted may be indicated in the centre portion 183, for example by a flashing indication.

[00205] In one specific embodiment, the user rotationally actuates the user interface component 180 to choose the temperature of a fixed volume of liquid to be dispensed, while the selected temperature and the volume of liquid to be heated and dispensed are displayed, as shown in Figures 28a to 28d. Alternatively, the selection may be of a discrete value of the volume to be dispensed for a fixed temperature, as illustrated in Figures 29a to 29d. If for example the liquid dispensing is available in four different volumes and four different temperatures then there would be 16 options that the user could intuitively choose by a simple rotation of the user interface.

[00206] In the illustrated embodiment, volume is indicated by level markings 186 in an image 185 of a cup, and temperature is indicated numerically 184. In alternative embodiments the temperature indicator 184 and volume indicator(s) 185, 186 could be indicated by different images; for example volume may be indicated by varying sizes of cup. Lighting effects may be incorporated in the portions 181, 182 and/or 183 to indicate different volumes and temperatures. The display or lighting effects may include animated images. It is also known that water boils at different temperatures due to, for example, variation in atmospheric pressure; therefore it may be advantageous to replace the numerical indication of 1000 with an image or the word Boil' for example.

[00207] The portions 181, 182 may rotate about the central portion 183, and may include a transparent or translucent cover over the central portion 183. The portions 181, 182 may themselves be transparent or translucent, for example so that illumination effects may be seen through them. Alternatively, there need not be separate portions 181, 182 and 183; instead, the display and the user actuable portions may be completely integrated, for example by providing a touch-sensitive screen over or around the display.

[00208] As an alternative to a rotationally actuable portion, the component 180 may include a two-dimensional touchpad arranged so that movement by the user in one orthogonal direction controls the setting of one parameter value, and movement in the other orthogonal direction controls the setting of the other parameter value.

[00209] The component 180 may be used to control the setting of more than two parameter values, using analogous methods to those described above. For example, the component may be used to control brew strength in a tea or coffee maker, in addition to liquid volume and temperature.

[00210] An additional indication or display may be used to indicate, for example, that the liquid is already warm enough to dispense or alternatively to show that there is no (or not enough) liquid to dispense.

[00211] The user interface 11 may be programmed to return to a preset temperature and/or volume setting once the liquid has been dispensed or alternatively return to the previously chosen option. A memory may be provided to store one or more favourite setting, whether set by the user or determined from previous settings, and, in a selected favourites mode, rotational actuation may cycle through the favourite settings rather than all possible settings.

100212] Tn the alternative embodiment in which the user interface component 180 is touch sensitive, the user may choose the option required by keeping a finger on a touch-sensitive portion as the display cycles through different options, and removing the finger when the required setting is displayed, or alternatively by moving the finger on the touch-sensitive portion, for example the intermediate portion 182, until the desired setting is displayed.

[00213] The diameter of the user interface component 180 may range from 25 to 75 mm dependent upon the appliance for which the component 180 is to be used.

[00214j The user interface component 180 may include an Eco' or sleep' setting to reduce the power drawn by the component when not in use, for example by dimming illumination of the display. The component 180 may leave this mode in response to an initial user actuation, such as a touch or rotation. When leaving the sleep' mode, the user interface component may revert to the previous parameter settings.

Turbulence Detection [00215] The following embodiments are concerned with methods of detecting boiling or simmering in a liquid heating vessel by emitting electromagnetic radiation towards the surface of the liquid and detecting reflection of the radiation from the surface, or transmission of the radiation through the surface, either of which are affected by turbulence in the surface, characteristic of simmering or boiling. In the preferred embodiment, an optical beam is transmitted substantially perpendicularly through the liquid surface and is detected by a detector substantially aligned with the beam.

[00216] Preferably, there is provided a least one pair of an optical transmitter and optical receiver, each of which is coupled with a lens. It is preferred that the lens has a flat top which is finished flush with or just above the surface in which the lens is provided, such as the element plate. The lens is preferably tubular so that the transmitter is held firmly, and may have a rounded, pointed or preferably flat end as shown in Figure 30a. Preferably, the lens is sealed against ingress of water or condensation to prevent moisture inside the lens interfering with the direction and strength of the optical signal.

[00217] The optical transmitter(s) can be installed below or above the liquid surface, with the corresponding optical receiver(s) being installed respectively above or below the liquid surface. The present inventors have found that optical receivers are less tolerant than optical transmitters to beads of condensation or splashed water when fitted above the liquid surface, so it is preferred that the optical receiver(s) is positioned below the liquid surface and the corresponding optical transmitter(s) above the surface. To further alleviate the effect of splashes of liquid, it is preferred that the optical transmitter is situated as high as possible above the maximum liquid level.

[00218] Tn a specific embodiment, suitable for small domestic water heating appliances in use in normal kitchen environments, the preferred transmission frequencies are in the range of 800 nm to 950 nm peak wavelength and with a preferred transmission beam angle of 15 -40°, preferably approximately 300. The transmitter may be a narrow bandwidth source such as an encapsulated LED. It has been found that this transmitter type is tolerant of beads of condensation or splashed water that may accumulate on the outside of downwardly facing lens installed above the water level. Nevertheless, turbulence can be sensed across a range of electromagnetic frequencies and the principles described herein are applicable to all suitable frequencies and suitable liquid types.

[002191 The preferred receiver(s) are in the same range of wavelengths as the transmitter: 800 nm to 950 nm peak wavelength. It is preferred to broadly match the wavelength of peak sensitivity to the dominant wavelength of the transmitter, with a total angle of sensitivity of 15 -40°.

[00220] The optical transmitter(s) and receiver(s) cooperate with an electronic control system and enable the system to assess the level of turbulence and optionally other data, for example the ambient illumination level, at different stages of the heating process.

[00221] The ambient illumination level provides an indication of the saturation of the chosen bandwidth that the optical receiver is experiencing. The ambient illumination level within the reservoir 5 is dependent upon the type of appliance, and in particular on the material of the vessel wall, for example stainless steel, plastic or glass. The detected ambient illumination level is also dependent upon the size and type of water windows and on the proportion of the ambient illumination level within the bandwidth of the receiver(s). Tn extreme cases the receiver can become blinded' or saturated if the ambient illumination is too high, hence the importance of specifying the correct bandwidth for each application type. The ambient illumination level is measured so as to calculate the level of turbulence, but may alternatively or additionally be measured for other purposes, for example to determine whether to inhibit heating if the ambient illumination level is above a predetermined threshold and/or to detect whether the lid is open.

[00222] The control system should detect a flat or gradually increasing fluctuation or turbulence signal during the pre boil stages of the heating process and a rapid increase in the signal as the liquid approaches boiling point. Tn preferred embodiments it is expected that the level of turbulence at boiling will be a minimum of five times the level of turbulence of the liquid at the beginning of the heating cycle.

[00223] Tn its simplest form, the method of turbulence detection comprises the comparison of minimum and maximum amplitudes of the received optical signal, until these amplitudes have reached a level at which the liquid is determined to be boiling. However, given the erratic nature of turbulence in that liquid that is being heated, then it is desirable during the heating process to compensate for at least some known and predictable variables such as: 1) liquid level 2) opacity of the liquid 3) expected external sources of electromagnetic radiation 4) scale build up on components in contact with water 5) tolerance of the electronic components 6) aging of the components 7) time since last boil 8) length of boil required 9) heat loss for a keep warm' process 10) overboil of liquid due to heat build up in heating elements, particular sheathed heating elements.

[00224] It is also desirable to compensate for transient variables and anomalies such as: 1) formation and movements of bubbles 2) movement caused by heat conduction 3) the appliance being knocked accidentally in use 4) unexpected external source of electromagnetic radiation 5) aeration of the liquid 6) tolerance of the components [00225] In order to compensate for the variables in a controlled manner the collection and analysis of the data is broken down into analysis segments of duration Ti. Each segment's time or analysis method can be modified during programming and/or operation to improve the performance of the appliance at different stages of the heating cycle. An analysis period (AP) of duration T2 is made up of two or more analysis segments Ti.

100226] For every analysis segment of duration Ti, the amplitude is measured using one or more methods, including the quadrature amplitude method as described in WO-A- 2009/060192, or a fixed phase method. Following the analysis period (AP) of duration T2, it is possible to determine the following data: * The maximum amplitude measured during the analysis period of all segments.

* The minimum amplitude measured during the analysis period of all segments.

* The average or mean amplitude measured during the analysis period of all segments.

[002271 The difference between the maximum and the minimum is stored as Raw Turbulence (RT) and this indicates how much the amplitude is seen to vary during the analysis period. The raw turbulence tends to increase as the liquid temperature increases. A predetermined threshold level may be set, above which the liquid is considered to be boiling and the appliance is switched off or into a keep warm mode.

1002281 As previously described, the measurement on which the raw turbulence is derived is dependent upon a number of variables which can significantly affect the data, so much so that the raw turbulence seen in 1.7 litres of water at boiling when the appliance is new (without scale) may be a factor of 10 higher than in the same appliance on minimum water level with lenses being subjected to scale. Therefore it is not preferred to set a standard threshold across a range of conditions based on the raw turbulence signal as measured. Instead, it is preferable to normalise the raw turbulence measurements so that the data is proportional across the whole range of conditions on a day-to-day basis and over the lifetime of the appliance.

[00229] Figures 30a and 30b illustrate how the amplitude may degrade if, for example, a lens becomes dirty or scaled. Each graph shows the same early stage of the heating process over an arbitrary period, but in Figure 30a the lens is clean whereas in Figure 30b it has become scaled, such that the level of amplitude is considerably lower. The centre portion of the graph is truncated for illustration purposes.

[00230] In Figure 30a: Mini = 3100 Maxi = 3200 Meani = 3150 InFigure30b: Min2 = 1033 Max2 = 1067 Mean2 = 1050 If we compare the Raw Turbulence (i.e. Max -Mm) for each example then RT1 = 100 and RT2 =34 RT1 is 300% larger than RT2 and this will be proportional across the heating process, thus causing difficulties in setting a threshold that would be suitable across both conditions.

[00231] One method of normalising' the raw turbulence is by calculating the ratio of the raw turbulence and mean amplitude during the analysis period, in which case Normi = RT1 / Meani = 0.032 Norm2 = RT2 / Mean2 = 0.032 Normi and Norm2 may then be multiplied by a predetermined constant based on the average of the expected Mm and Max over the length of the boil and over all the expected conditions, for example 2,000, so that the Normalised Turbulence is in the same numerical range as the Raw Turbulence e.g. Normi =64 Norm2 =64 The normalised data is again proportional across the heating process and thus allows one predetermined threshold to be set for most conditions.

[00232] It has been found that during the heating process it is quite likely that a spike' may occur in which the normalised turbulence in one or more analysis periods reaches a higher level than the preset threshold. These spikes may be caused by a large bubble forming on the heating element or the appliance being accidentally knocked and it is important that this does not cause the appliance to be switched off prematurely.

[002331 Given these conditions, it is desirable that the appliance should not be programmed to switch off each time the normalised turbulence reaches the threshold in any individual analysis period; instead, it is preferred to look for a succession of occasions when the normalised turbulence reaches the threshold, which is stored as a Boil Count'.

[00234] To calculate the target boil count it will be desirable to identify the characteristics of the water heating appliance and the required performance.

[00235] The following example is based on a Turkish teamaker with a mechanical (i.e. sheathed) element where it is expected that the appliance will switch off after three seconds on first boil and after one and half seconds on subsequent boils or in the keep warm mode.

[00236] The above criteria have been used as a basis for a significant amount of test work where each individual segment' has been optimised for consistency, tolerance and accuracy over all water levels and voltage ranges and to ensure the required distinct change is present in the normalised turbulence when the appliance reaches boiling point.

[00237] Tt is preferred that the amplitude is measured using a combination of the quadrature amplitude method as described in WO-A-2009/060192 and a fixed phase method. The preferred range for segment Ti is 5 ms to 15 ms. The preferred range for segment T2 is 25 to 75 times Ti. A preferred range for the analysis period (AP) is 0.25 to 0.75 seconds for a Ti of i0rnS.

[00238] If for example the analysis period is set at 0.5 seconds, then to achieve a three second first boil, the boil count would be need to hit a target of six and to achieve a one and a half second reboil or keep warm, then the boil count target would be three.

[00239] In some conditions there may be more than one spike' during a heating cycle which may cause nuisance tripping of the appliance if the cumulative number of spikes was greater than the target boil count; therefore it is desirable for the method to differentiate between a number of separate spikes not indicative of boiling and the pattern of normalised spikes seen at boiling. This can be achieved by giving a positive value to counts above the threshold and a negative value to any subsequent analysis periods that are below the threshold, so that the boil count would revert to nought immediately after a single spike, and therefore the boil counts above the threshold would need to be successive, not just cumulative, in order for the appliance to switch off [00240] One example would be to give equal values of boil count increment and decrement for each analysis period that results in a normalised turbulence above and below the threshold respectively. However it has been found that if an appliance is reboiled continuously, then the turbulence can become even less predictable (slower but larger amplitude "macro" turbulence as opposed to rapid but lower amplitude "micro" turbulence) and the normalised turbulence can fluctuate above and below the threshold. In that case, it is desirable to allocate a larger increment value than decrement value, for example plus 1.0 and minus 0.2 respectively, so that providing there was at least 1 normalised turbulence measurement above the threshold for every 5 normalised turbulence measurements below the threshold, then the boil count value would still have a net increase and eventually reach the target value.

[00241] It has also been found, particularly with large mass elements, that the turbulence continues for a short while after the appliance has switched off; however it is desired by some users that a jug kettle should be able to be manually resettable (i.e. switched on) immediately if desired. Tn order that the user is able to reboil immediately, irrespective of the state of the appliance, the boil count may revert to nil when the heater is reenergised.

[00242] Tt is also proposed that the method recognises an immediate reboil and reduces the target boil count in response thereto, to save energy. Recognition of an immediate reboil could be based on the time lapse since the last boil event and providing the reboil was within the preset time limit then the target boil count would be reduced.

[002431 Keep warm may be achieved by reenergising the appliance a set time after the boil event, and the target boil count can be reduced relative to that for initial boil, according to requirements. The keep warm method may also include a time limit, such as two hours, after which the appliance would be de-energised.

[00244] It is expected that this method of optimising the data will work for periods outside the preferred ranges for Ti, T2, and the Analysis Period, in particular, if the vessel shape or volume of the liquid is different.

[00245] The user may have two selectable options: the first option is to allow the water to reach a predetermined state of turbulence and then de-energise the heating element 39; with the second option the element 39 will de-energise after the first predetermined state of turbulence has been reached and then re-energise periodically until a second predetermined state of turbulence has been reached. In this embodiment the re-energisation will take place on a timed basis, for example, every minute so that the system acts as a energy regulator. The element may be reenergised at full power or reduced power, or alternatively a separate heating element (not shown) may be utilised to for re-energisation.

In an alternative embodiment a thermistor (not shown) may be utilised to act a lower temperature indicator and trigger the element to reenergise.

[00246] Tn other embodiments only one of the above two options may be made available.

[00247] In addition to the above there are hardware and software tolerance issues to be aware of which can be overcome as follows.

Phase Locking [00248] The receiver is programmed to deduce the optimum instances at which the amplitude of the received signal is to be sampled (for example, at the peaks of a filtered sinusoid). This has a large benefit in reducing the influence of external changing light sources such as that from artificial lighting whilst maximising the measurement resolution.

The timing of the sampling is kept at a precise phase with respect to the transmitted infrared signal.

Receiver sensitivity to modulation frequency [00249] Tt is preferable to implement a band-pass filter, or phase-locked-loop filter in the receiver to minimise the influence of other light sources and to improve signal-to-noise ratio. A suitable band-pass filter however can be subject to a typical tolerance of ±10% for its centre frequency. Over time, that tolerance can be as wide as ±20%. To ensure optimum performance, maximum measurement resolution, maximum signal-to-noise ratio and minimum influence from external light sources, the modulation frequency of the transmitted signal can be adjusted by the method. The frequency is automatically adjusted continuously to obtain the maximum possible received amplitude, thereby ensuring the intended signal is a close as possible to the centre frequency of the band-pass filter.

[00250] Tn one embodiment, the transmitted infra-red signal is modulated, at a typical frequency of 2.5 kHz. The system will be more tolerant to external light sources if the band width of the receiver (band-pass filter) is narrow, for example 2.5 kHz ±5%. However the tolerances of electronic components, together with the effects of temperature and ageing can yield an overall tolerance of centre frequency of ±20%. This can result in the frequency of the transmitted signal being outside the bandwidth of the band-pass filter, resulting in a poor received signal amplitude.

[00251] The inventors overcome this by adjusting the transmitted modulation frequency to ensure that the transmission frequency matches as closely as possible to the centre frequency of the band-pass filter in the receiver. This results in a working frequency that is dynamic' as opposed to preset. The frequency is adjusted in small steps (approximately 1% steps) every 500mS, ensuring that the optimum frequency is maintained even during rapid temperature changes or other influences on band-pass performance.

Band-Pass Filter Behaviour [00252] In one preferred embodiment, a band-pass filter is used to reduce the influence of external light sources and to maximise signal-to-noise ratio of the received signal. The centre frequency is chosen to match the frequency of modulation of the transmitted signal. Figure 31 illustrates how the filter's gain is maximum when the signal frequency is at the centre of the response curve. Additionally, the phase relationship is plotted on the same figure and shows that the phase of the input signal to the output signal is 00 (in phase). This is illustrated also in Figure 32.

[00253] Tf the signal frequency is slightly low (-5%) compared to the centre frequency of the band-pass filter, the filtered signal amplitude is significantly reduced and its phase relative to the input signal is no longer 00.

[00254] Similarly, if the signal frequency is slightly high (+5%) compared to the centre frequency of the band-pass filter, the filtered signal amplitude is significantly reduced and its phase relative to the input signal is no longer 00.

[00255] To maximise the received signal-to-noise ratio, it is preferable to use a transmitted frequency which is as close as possible to the centre frequency of the band-pass filter.

Fixed Phase Amplitude Measurement [00256] The fixed phase measurement method offers improved rejection of external influences such as artificial lighting. This method is only effective however if the precise phase relationship between the transmitted infra-red modulation and the received signal from the band-pass filter is known. The phase relationship is known precisely when the frequency of modulation is the same as the centre frequency of the band-pass filter. When the modulation frequency is not very close to the centre frequency of the band-pass filter, the phase of the received signal shifts considerably with respect to the phase of the transmitted signal.

[00257] The principle of fixed phase measurement is shown in Figure 36. Samples of the signal's amplitude are captured at the precise instances that the signal is at a positive and negative peak. The amplitude is simply the value of one peak subtracted from the other peak. This is only valid if the times at which the samples are taken is very precisely on the peaks of the sinusoid.

Quadrature Amplitude Measurement [00258] The quadrature method can provide an amplitude measurement irrespective of the relative phase between the transmitted signal and the received signal. Quadrature measurement relies on 3 samples per sinusoidal cycle, each separated by 90° (1/4 cycle).

The absolute phase of the 3 samples however is completely unimportant. Figure 35 illustrates the principle of operation for quadrature amplitude measurement. Quadrature measurement however is a little less immune to influence from external light sources.

[00259] For one preferred embodiment, the quadrature method is used to assess the received amplitude over a span of modulation frequencies (where the relative phase between received and transmitted signals is unknown). The highest amplitude then relates to the centre frequency of the band-pass filter.

[00260] The fixed phase measurement method, which measures the amplitude by precisely sampling at the positive and negative peaks of the received signal, is then used to determine turbulence measurements.

[00261] In order to assess the best frequency to use during the appliance operation, the response of the filter can be determined by sweeping the transmitted frequency from 20% to +20% of the nominal centre frequency of the band-pass filter. The amplitude of the received signal however cannot be reliably measured using the fixed phase method if the transmitted frequency is not very close to the centre frequency of the band-pass filter, so quadrature measurement is used.

[00262] When the best operating frequency is determined, the system uses fixed phase measurement for assessment of turbulence.

Optical gain [00263] The optical measurement system comprises a series of filters and amplifiers which can be optimised to each appliance type at the programming stage, with the receiver amplification being increased if the received JR level is too low; this is known as optical gain. Alternatively or additionally, the intensity of the emitted light may be adjusted.

[00264] The inventors recognise that this aspect could also be dynamic, for example monitored over the life of the appliance and/or certain light conditions and the gain and/or intensity increased or decreased as required if the mean amplitude of the received signal falls outside a certain level.

Threshold [002651 Given the capability of the method to recognise and diagnose problems, the threshold could also become dynamic. For example the method could self-calibrate on first use, so that the threshold is set at the optimum point. Throughout the life of the appliance, the method could analyse the average levels of turbulence at known points, for example switch on' and switch off, and compare against the current threshold, at which time the method could then modify the threshold up or down as required to maintain optimum performance.

[00266] Alternatively the threshold could be calibrated separately for each boiling cycle, based on a running average of the mean or raw turbulence so that the boil count starts if the measured threshold is say 100% (determinable for each appliance type) higher than the average of the previous three analysis periods. The average of these three periods then becomes the base line for the boil count which would continue to count upwards providing the turbulence either increased continued at this level. This same base level could then be used as the base level for keep warm and reboil. The base level would be reset if the appliance was not energised for say 5 minutes or if removed from the appliance base for filling or pouring.

Computer program [00267] The above turbulence detection and boiling/keep warm control methods may be implemented in hardware, software and/or firmware, and may be implemented as a computer program comprising program steps for implementing the method. The computer program may be designed for execution in a microcontroller, such as the microcontrollers 10 and/or 15. The computer program may be stored on a carrier for loading into an appliance at the time of manufacture, or as an upgrade or modification. The computer program may be transmitted as a wireless or wired signal over a suitable communications link.

Emitter and Receiver Installation [00268] Figure 37a illustrates an isometric cross section of a vessel 1 which includes an optical emitter 190 at the top of the vessel 1 and an optical receiver 191 positioned at the bottom of the vessel 1. Each of the emitter 190 and the receiver 191 is mounted in a lens 192 which makes a waterproof seal flush with, or slightly protruding through, the respective water proof housing 26 and element plate 12. The emitter 190 and receiver 191 are aligned vertically and are positioned to one side of the water window 25. The appliance includes a power supply 17 for the electronic control 60 positioned beneath the element plate 12 and a user interface 11 positioned in the handle 7. The vessel 1 includes an integrated 360° control/connector 60, for example an Otter Al 1 which interfaces with a corresponding connector in the base 2. In alternative embodiments the power supply 17 and user interface 11 may be in the base 2 in which case the cordless connector 60 may be optically coupled thereto, for example as described in the Cordless' section above or may employ an alternative method to communicate between the vessel 1 and the base 2. The vessel 1 may be waterproof or dishwasher proof.

[00269] The vessel 1 is designed for use with a lid (not shown) or alternatively may be used in conjunction with a separate teapot positioned in the aperture 20, for example for use as a Turkish teamaker.

[00270] For a 1.7 litre jug kettle it has been found that the optimum position for the emitter 190 and the receiver 191 are as follows: the transmitter 190 is positioned as high as possible above the maximum water level facing downwards at 900 to the water level in still conditions and the receiver 191 is positioned on the base of vessel 1 facing upwardly at 90° to the water level, with the transmitter 190 immediately above the receiver 191.

[00271] Figure 37b illustrates the underside of vessel 1 in this embodiment. The element plate 12 is provided with a sheathed heating element 39 in which the cold tails 40 have been spaced apart so that there is sufficient space for the power supply unit 17; however in other embodiments the heating element 39 may be a thick film printed element, a diecast element or other suitable heating means. The power supply mounting points 37 share the same mounting points 36 as the control 60. The triac 38 is separate to the power supply and can be mounted (as illustrated) onto the mounting point 36 or alternatively onto the element plate 12, either of which mounting points will act as the required heatsink.

[00272] The lower part of the lens 192 and receiver 191 may be attached to the power supply 17 or alternatively these may be supported by other means, for example the appliance base 2. If supported by another means, the power supply 17 may still provide interim or temporary support for the lens 192 and/or receiver 191 during assembly.

[00273] Figure 37c is an isometric view of a vessel 1 with the top part of the handle 7 removed to illustrate the user interface 11 and the user input means 1 lb. Additional functions [00274] The vessels disclosed above may, where applicable, have one or more additional features, such as a keep warm' feature, in which the liquid is maintained around a predetermined temperature, preferably after boiling; this may be done by intermittent activation of the main heating element, or by intermittent or continuous activation of a secondary heating element (not shown). The predetermined temperature may be just below boiling point, or a lower temperature such as 80°C, and may be selectable by the user.

[00275] Another heating feature is a sub-boil feature, in which the liquid is heated up to a predetermined temperature below boiling, such as 80°C for making coffee, and the heating power is then switched off or reduced, for example to activate a keep warm mode.

The predetermined temperature may be selectable by the user.

[00276] Another heating feature is a prolonged boil feature, whereby the liquid is heated to boiling and then boiled for at least a predetermined time, such as 30 seconds to 2 minutes, to sterilize the liquid.

[00277] The vessels described above may be designed for heating liquids such as milk, soup and/or sauces instead of or as well as water. The vessel may form part of an appliance including additional functions or components, for example an electrical motor for pumping, blending, chopping or frothing the contents of the vessel. The functions may include a user interface.

[00278] Additional example appliances may include food processors, blenders, irons, wasserkochers, coffee and espresso makers, juicers, smoothie makers, pans, soup makers, sauce makers, steamers, tea makers, chocolate fountains, fondues, slow cookers and milk frothers. It will be appreciated that the above list is not exhaustive.

Heating, Controlling and Dispensing Small Volumes of Liquid [00279] The following embodiments improve the functionality of appliances when heating small volumes of liquid. The specific embodiments show a metal pot arrangement with a sheathed element attached to, or die cast into the pot; however this is schematic only and the embodiments are also applicable to plastic, glass or ceramic vessels incorporating underfloor or immersed elements of any type and fixture method.

Volume Related Temperature Sensing 1002801 Tn a vessel of 150mm diameter, the liquid height for a volume of 50m1 is only 10mm and it has been found that there can be a temperature differential of up to 20°C across the volume of the liquid. This temperature differential makes it more difficult to ascertain the average (or dispensed) temperature of the liquid.

[00281] One method to improve this differential is to provide a more uniform heat distribution across the element in the base of the vessel. In the case of a mechanical element this can be achieved by elongating the sheath so that the sheath covers a greater surface area of the surface to be heated.

[00282] Another method to improve the differential is to utilise a highly conductive material for the pot, for example aluminium.

1002831 Another method to improve the differential is to create a flow in the liquid so that it is mixed as it is heated. This can be achieved by a pump to circulate the liquid or an impellor to stir the liquid. Alternatively or additionally the liquid can be introduced into the heating chamber at different stages through out the heating cycle so as to agitate the water.

Furthermore the liquid inlet may be positioned horizontally towards the bottom of the heating vessel so that introduction of the liquid may encourage circulation.

[00284] The above methods will assist in providing a constant temperature across the liquid to be heated, but there are further issues to overcome in sensing or controlling the liquid temperature particularly the temperature lag between the heating means and the liquid to be heated, and the resultant overshoot of the heat into the liquid after the heater has been de-energised.

[00285] It has been found that improved performance can be achieved by the use of one or more thermistors attached to, or through, the element so that the required temperature can be accurately controlled by measuring a combination of temperature reached and time elapsed.

[00286] Figure 38 illustrates an underfloor element with five thermistor positions: 214a which passes, in a sealed arrangement, through the substrate into the liquid, 214b which is close to the top surface of the substrate, 21 4c which is close to the bottom surface, 214d which is on the bottom surface and 214e which is on a raised portion below the bottom surface. The thermistors furthest away from the water are influenced more by the temperature of the sheath and vice versa. Experimentation has shown that each thermistor position is subjected to a finite range of temperatures over a given time when the element is energised in different conditions.

[002871 For example, when the element is energised without liquid each thermistor on the dry side reaches its peak temperature faster than when liquid is present. When energised with, for example, 300m1 of liquid the rate of rise of the thermistor closest to the liquid (214b) is slower than the rate of rise of the thermistor furthest away (215e). When energised with 150m1 of liquid the rate of rise at 214b will be faster than when energised with 300m1 of liquid. When refilled and reenergised immediately after boiling, the heatsink effect of the added liquid will be greater at 214b than 215e and both will have a higher start point than when heating from cold.

[00288] So it can be seen that it is possible to compile a sequence of temperatures related to the different thermocouple positions, the volume of liquid and the length of time since the heater has been energised. This data can be compiled from a combination of empirical measurements in known conditions and extrapolations based on the empirical measurements so that a database is available for all conditions, in which case an algorithm can be configured to control the liquid temperature in the appliance to a user requested value dependant upon the relative temperatures of the thermistors during different stages of the heating process.

[00289] The above embodiment can be optimised by a production line or software check on the resistance of the element or the current drawn during the heating process.

[00290] The above embodiment can be further optimised by the control software measuring the voltage of the electrical supply so that any variance in power can be factored into the control sequence.

[00291] The above embodiment can be further optimised so that the final part of the heating process will utilise the heat stored in the element.

[00292] The inventors understand that installing five thermistors is unlikely to offer a cost effective solution. However it has been found that an acceptable results can be achieved using either two or three thermistors.

[00293] Tn appliances as described in WO 2010/09495, where a known volume of liquid is heated, then the number of thermistors could be reduced to one providing that the thermistor can provide data to show the starting temperature of the element before the liquid is added and also a rate of rise influenced by liquid being heated.

[00294] In embodiments where the volume and start temperature of the liquid are known, then the control sequence may be a simple matter of a timed energisation based on some or all of the following six criteria: * Start temperature of the liquid * Volume of liquid * Start temperature of the element * Resistance of element * Voltage * Volume of liquid [00295] In embodiments where liquid is pumped from a reservoir 187 into a heating chamber, the heating chamber may include a liquid level sensor for example as previously described in or around the heating chamber or the reservoir 187 so that the pump is de-energised when the preset volume is reached.

Quickly Dispensing the Heated Liquid 100296] Upon the liquid reaching the required temperature it is important that the liquid is dispensed quickly without any of the heated liquid being retained in either the heating part or the dispensing part of the liquid heating vessel. For optimum energy efficiency all vessels, sumps or tubes used in the liquid heating process should be completely purged during the dispensing cycle.

[00297] Tt is also important to ensure that there are no unheated areas of liquid in the system at the end of the heating process (for example isolated between the heating chamber and dispensing valve), otherwise it will not be possible to dispense liquid at or near to boiling point.

[00298] It should also be understood that in a wide diameter heating vessel, for example 150mm, small volumes of liquid require an outlet diameter of a minimum 15mm and preferably 22mm to achieve an acceptable flow rate due to the reduced head of pressure.

A separate dispensing valve of this size, either manual or electromechanically activated, is bulky and more likely to provide a slug of unheated water between the vessel and the valve.

100299] Tn a first embodiment schematically illustrated in Figure 38 there is provided a heating vessel 1, which may be utilised in an appliance designed to supply Hot Water on Demand as described in WO 2010/094945. The heating vessel 1 is provided with a separate lid 226, which may be removable. The base part includes a heating plate 12 and element means 39.

[00300] The base part of the vessel incorporates an integral outlet 216 which may be formed or moulded as part of the vessel or as part of or attached to a separate heating element. The top of the outlet 217 forms a sealing face against a conical sealing means 218.

The sealing face of the outlet 217, which may include an additional localised portion of sealing material (not shown), is level with or marginally lower than the vessel base and there is no cold slug of liquid formed, so that all the liquid is dispensed from the vessel under gravity when the sealing means 218 is removed.

[00301] The sealing means 218 can be manually activated or preferably is electro-mechanically activated via a mechanical connector, such as a pushrod 212 through the lid of the vessel. In the preferred embodiment the pushrod 212 is attached or part of a solenoid actuator 211 with a solenoid coil (not shown) provided in a removable housing 210 attached to the lid 226. The pushrod 212 is preferably of a food grade material and is positioned through a lid aperture which may include seals 230 to help prevent heated liquids and gases entering the solenoid coil.

[00302] The entire lid 226 or the solenoid housing 210 may be removable so that the sealing means and sealing face 217 and 218 may be cleaned if required.

[00303] Figures 39b and 39c show alternative sealing arrangements where the sealing means 218 may be profiled or flat, respectively. The sealing means 218 may be located substantially within the chamber, or the pushrod 212 may extend partly or completely through the outlet 216 so as to seal against the sides and/or lower end of the outlet 216. Tt should also be understood that any suitable sealing means, for example a ball shaped seal, may be employed.

[00304j In some cases for example if the distance between the solenoid and the sealing means is too long then support means 220 and or 221 as illustrated in Figures 39d and 39e may be provided for the pushrod 212 and the sealing means 218. The support means 220 may be a tube in which the pushrod passes through and may be used to prevent water splashing through the lid 226 into the solenoid housing 210. The sealing means supports 221 should be discontinuous so that they do not prevent the liquid from discharging through the outlet 216 [00305] A void 222 is provided above the maximum water level 225 for expansion during the heating process and a vent 215 with optional baffle 227 is provided for venting any gases produced during the heating process. The vent 215 will act as an over flow if the vessel is overfihled and also to act as a depressurisation means when the liquid is being dispensed.

[00306] The vent 215 may discharge into a reservoir 187 within the appliance or preferably discharges through the outlet 216 so that any steam can be utilised to preheat the user's vessel 219 for example a cup or mug. Additionally the user would be made aware immediately a fault condition occurs and the heating vessel overflows. The vent may communicate with outlet 216 outside the vessel 215a or through the vessel 215b as illustrated in Figure 40.

[00307] Any of the vent arrangements may also act to provide steam to a steam sensor (not shown) for example to switch off the appliance when the liquid has boiled.

[00308] In alternative embodiments the vessel 1 may be sealed so that the liquid is dispensed though the outlet by the force of the build up of pressure. The vessel may include an additional one way valve (not shown) to act as depressurising means and should include a pressure relief valve (not shown). A pressure activated valve may be used as the means to activate the solenoid valve [00309] Figures 39a and 40 show alternative lid arrangements 226 where the void 222 is reduced in volume and/or the void 222 is provided around the solenoid housing 210.

[00310] Figure 41a shows an alternative embodiment where the void 222 communicates directly to the outlet 216 through a hollow pushrod 228 and sealing means 218. Excess liquid and gas can be evacuated through an aperture 224 in the pushrod and during the dispensing mode air can enter the heating vessel in the opposite direction. The aperture 224 may be protected by a baffle (not shown) to prevent liquid splashing through the aperture 224 during the heating cycle.

[003111 Figure 41b shows an alternative arrangement to Figure 41a where a combined pushrod and sealing means 234 is formed from the same material, which will enable a larger volume of air or water to pass through the centre. The combined pushrod and seal 234 may incorporate an aperture 224 or a series of apertures 224 or may incorporate an intermediate part 232, as shown in Figure 41c, that acts to attach the combined push rod and sealing means 234 to the actuator 224 through an aperture 229.

1003121 As an additional feature (not shown), means for stirring or agitating the liquid during heating may be provided around or associated with the pushrod 228, and may be connected to a motor for driving the means for stirring or agitating. For example, the motor may drive a rotatable hollow shaft provided around the pushrod 228, the shaft having an impeller for stirring the liquid. Alternatively, there may be a reciprocable member mounted on the pushrod 228, reciprocally driven by the motor. The motor may be provided on or in the lid 226. Alternatively, the solenoid may be coupled to the agitator/stirrer.

Alternatively, the push rod 226 may be rotatable relative to the sealing means 218, with agitating or stirring means attached to the push rod 228.

[003131 Figures 42a and 42b show alternative embodiments where the valve housing 231 is moulded as part of a plastic vessel.

[00314] Tn Figure 42a an aperture 233 is formed in the side of the vessel and is sealed by a horizontal acting sealing means activated by a manual (not shown) or electro mechanical actuator for example a solenoid 210 or motor (not shown). The vent tube 215c also communicates through the side of the vessel 1 either along side or above the aperture 233 with any overflow of liquid or gas exiting around the pushrod 212 through into the outlet 216.

[00315] Figure 42b illustrates an alternative to Figure 42a in which the sealing means 218 is slidable across an aperture 233 in the bottom of the vessel 1. In this embodiment the vent tube 215d communicates through the bottom of the vessel alongside the aperture 233.

1003161 Each of the above embodiments integrates the function of the heating vessel 1 and the dispensing valve housing so that the overall height of the appliance is optimised, the liquid flow rate is increased and cold slugs avoided in comparison to a separate vessel and dispensing valve housing.

[00317] Tn alternative embodiments the liquid temperature may be regulated by turbulence detection as previously (or subsequently) described. In which case for temperatures lower than boiling additional liquid will need to be mixed with the boiling liquid to provide the required temperature.

[00318j Figures 43 and 44 illustrate the outward appearance of an On Demand' hot water appliance 200 that includes a water heating generator as described above. The appliance 1 includes a wrap around reservoir 187 that may include markings 201 to indicate the water available for use.

[00319] The appliance as illustrated includes an on-off user actuator 11, a rotatable temperature indicator 180 and a slidable cup volume selector 202 and may include a lighting sequence to show which option has been chosen.

[00320] Tn operation the user selects the temperature and volume of water required and places a cup 219 onto the drip tray 188. The appliance may incorporate a sensor or switch 189 so that a cup 219 needs to be in place before the heated water is dispensed. Once selected and actuated the pump (not shown) fills the heating chamber I to the required level from the reservoir 187 and the heating cycle commences. Once the heated water has been dispensed the user selected options may remain in place for subsequent use without the need to reset.

[00321] In its simplest form the appliance 200 may be controlled by a steam sensor (not shown) linked to the solenoid 210 so that when the sensor is switched on the sealing means 218 is activated and the heating means 12 is energised. On sensing boiling the steam sensor would de-energise both the heating means 12 and the solenoid coil 210 so the heated water is dispensed.

[00322] The appliance of Figures 45a and 45b includes a wrap around reservoir 187 that is removable for filling. The removable reservoir also includes a pump (not shown) that delivers the required amount of water into the heating chamber (not shown) through an outlet 193. The reservoir 187 also includes an inlet to receive an overflow pipe from the heating chamber. Both the inlet 194 and outlet 193 are positioned above the water level in the reservoir 187 so that no additional sealing means are required when the reservoir is removed from the main appliance. Power is supplied to the removable reservoir via a cordless connector 3 from the main appliance part.

In other embodiments the pump may be positioned in the main appliance in which case there will be no need for the cordless connector 3.

[00323] Tn this embodiment the user interface 11 comprises a series of buttons but this and other embodiments may utilise any of the previously described user interface arrangements including the rotational user interface 180 may include all the functions required to select and operate the appliance 200.

[003241 In the appliances of Figures 43 to 45, the main appliance body including the reservoir 187 may be rotatably mounted about a substantially vertical axis, to facilitate access to the reservoir 187 for removal and/or replacement. The rotatable mounting may comprise a 3600 connector, or alternatively a turntable without a power connection.

Alternative Embodiments [00325] The embodiments described above are illustrative of rather than limiting to the present invention. Alternative embodiments apparent on reading the above description may nevertheless fall within the scope of the invention.

Claims

Claims 1. A removable and replaceable component for a liquid heating vessel, the component including a lid and a hinge mechanism integrated within the component.
2. The component of claim 1, ftirther including an integral spout.
3. The component of claim 1 or 2, further including an integral handle.
4. The component of any preceding claim, including attachment means for removably attaching the component to the vessel.
5. The component of any preceding claim, including sealing means for sealing the component to the vessel.
6. The component of any preceding claim, including spill-inhibiting means.
7. The component of any preceding claim, including user actuable lid opening means.
8. A waterproof appliance including the component of any preceding claim.
9. A liquid heating and dispensing apparatus, comprising a liquid heating chamber, an outlet for dispensing liquid from the chamber, and sealing means for selectively sealing against the outlet.
10. The apparatus of claim 9, wherein the sealing means is arranged to seal at a position substantially at or below the bottom of the chamber, such that substantially all of the contents of the chamber is dispensed when the valve is opened.
11. The apparatus of claim 9 or 10, wherein the sealing means is electromechanically actuable.
12. The apparatus of claim 11, wherein the sealing means is actuated by a solenoid.
13. The apparatus of any one of claims 9 to 12, including a vent connected to the outlet from above the liquid level in the chamber.
14. The apparatus of any one of claims 9 to 13, wherein the sealing means is actuable by a mechanical connector extending through the chamber.
15. The apparatus of claim 14, wherein the mechanical connector extends substantially vertically through the chamber.
16. The apparatus of claim 14 or 15, wherein the mechanical connector includes a passage extending from above the surface of liquid within the chamber to the outlet, so as to provide a vent through the sealing means.
17. The apparatus of any one of claims 14 to 16, wherein the mechanical connector provides said sealing means.
18. The apparatus of any one of claims 14 to 17, including a stirrer or agitator provided on or around the mechanical connector.
19. The apparatus of any one of claims 9 to 18, wherein the valve is actuable by means mounted in or on a lid of the chamber.
20. A liquid heating apparatus, comprising a liquid chamber, a heater for heating liquid within the chamber, a plurality of temperature sensors having mutually different thermal coupling with the heater and/or with liquid within the chamber, and control means for controlling the temperature of liquid within the chamber dependent on a comparison of the temperatures sensed by the sensors at different times during heating.
21. The apparatus of claim 20, arranged to switch off or reduce heating of the liquid before boiling, so that residual heat in the heating element heats the liquid to boiling.
22. A liquid heating apparatus, comprising a liquid chamber, a heater for heating liquid within the chamber, means for filling the liquid chamber to a predetermined volume, at least one temperature sensor arranged to sense the temperature of the heater and/or the liquid within the chamber, and control means for controlling the temperature of liquid within the chamber dependent on a comparison of the temperature sensed by the one or more sensors at different times during heating.
23. The apparatus of any one of claims 20 to 22, wherein the control means predetermines an energisation time for the heater.
24. A spill-inhibiting apparatus for a liquid heating vessel having an outlet for dispensing liquid, the apparatus having a valve through which the liquid can be dispensed, the valve being arranged to close when the vessel is tipped to one side relative to the outlet, and to open when the vessel is tipped towards the outlet.
25. The apparatus of claim 24, including a member moveable under gravity when the vessel is tipped to one side, so that the valve closes.
26. The apparatus of claim 25, wherein the member includes a valve sealing face that closes the valve when the vessel is tipped to one side.
27. The apparatus of claim 25, wherein the member is arranged to cooperate with the valve such that the valve is closed when the vessel is tipped to one side.
28. The apparatus of any one of claims 25 to 27, wherein the member is biased to open the valve when the vessel is tipped towards the outlet.
29. The apparatus of claim 28, wherein the bias is provided by biasing means integrated with the member.
30. The apparatus of claim 28, wherein the bias is provided by a single resilient member.
31. The apparatus of any one of claims 25 to 30, wherein the member includes a pressure relief valve arranged to relieve excess pressure when the first said valve is closed.
32. The apparatus of any one of claims 25 to 31, wherein the member includes a filter arranged to filter liquid as it is dispensed through the outlet.
33. The apparatus of any one of claims 25 to 32, wherein the member is movable over a supporting surface.
34. The apparatus of claim 33, wherein at least one of the member and the supporting surface has one or more protrusions extending into contact with the other, so as to reduce friction therebetween.
35. The apparatus of claim 33, including a carnming arrangement between the member and the supporting surface, such that the member is free to move until it reaches a position at which the valve is closed.
36. The apparatus of any one of claims 33 to 35, wherein the supporting surface comprises a lower lid surface.
37. The apparatus of claim 36, wherein the member is mounted above the lower lid surface.
38. The apparatus of claim 36, wherein the member is mounted below the lower lid surface.
39. The apparatus of any one of claims 25 to 38, wherein the member is pivotally mounted about a substantially vertical axis of the vessel in an upright position, the member being arranged to pivot under gravity when the vessel is tipped to one side.
40. The apparatus of any one of claims 25 to 39, wherein the member is arranged to open a vent when the vessel is tipped to one side.
41. The apparatus of claim 40, wherein the vent is opened at an upper side of the vessel when the vessel is tipped to one side.
42. The apparatus of claim 40 or 41, further including a chamber, segregated from the outlet, for containing liquid escaping through the vent.
43. The apparatus of claim 42, wherein the chamber is arranged to drain into the vessel when the vessel is in the upright position.
44. The apparatus of any one of claims 24 to 41, wherein the valve is arranged to close when the vessel is in an upright position.
45. The apparatus of any one of claims 24 to 41, wherein the valve is arranged to open when the vessel is in an upright position.
46. The apparatus of any one of claims 24 to 45, wherein the valve is arrange to be locked in the closed position until released by user actuation.
47. The apparatus of any one of claims 24 to 46, including a steam passage for conveying steam indirectly from the vessel.
48. A spill-inhibiting apparatus for a liquid heating vessel having an outlet for dispensing liquid, the apparatus including a vent arranged to be at an upper side when the vessel is tipped to one side, the vent opening into a chamber, segregated from the outlet, for containing liquid escaping through the vent.
49. The apparatus of claim 48, wherein the chamber is arranged to drain into the vessel when the vessel is in the upright position.
50. A spill-inhibiting apparatus for a liquid heating vessel, the apparatus having a valve through which liquid can be dispensed, the valve being arranged to open under steam pressure within the vessel, and being arranged to close when the vessel is tipped over.
51. The apparatus of claim 50, wherein the valve includes an overcentre mechanism responsive to tipping of the vessel.
52. The apparatus of claim 50 or claim 51, wherein the valve is arranged to be normally closed when the vessel is in an upright orientation.
53. The apparatus of claim 52, wherein the valve has first sealing faces that close when the vessel is in an upright orientation, and second sealing faces that close when the vessel is tipped.
54. The apparatus of any one of claims 50 to 53, including a user-actuable mechanism that, when actuated, prevents the valve from closing when the vessel is tipped, to allow dispensing of liquid through the valve.
55. The apparatus of any one of claims 50 to 54, wherein the valve is arranged to remain open when the vessel is tipped in a predetermined orientation.
56. The apparatus of any one of claims 24 to 55, wherein at least one sealing face of the valve comprises a localised portion or layer of sealing material so as to improve the sealing properties of the valve.
57. The apparatus of any one of claims 24 to 56, including an alarm for indicating that the vessel is tipped over.
58. The apparatus of any one of claims 24 to 57, including means for disconnecting electrical power to the vessel in response to the vessel being tipped over.
59. A spill-inhibiting apparatus for a liquid heating vessel having an outlet for dispensing liquid from the vessel, the apparatus comprising a user actuable mechanism arranged to open the dispensing outlet for dispensing when actuated, the user-actuated mechanism being biased to a closed position so that liquid cannot be dispensed through the dispensing outlet, the apparatus further comprising a steam passage for conveying steam indirectly from the vessel.
60. The apparatus of claim 59, wherein in the closed position the dispensing outlet is open to the steam passage.
61. The apparatus of claim 59 or 60, wherein the steam passage opens towards an opposite side of the vessel from the dispensing outlet.
62. The apparatus of claim 59, wherein the steam passage is separate from the dispensing outlet.
63. The apparatus of claim 62, wherein the steam passage includes a valve that opens under steam pressure.
64. The apparatus of claim 63, wherein the valve is arranged to close when the vessel is tipped.
65. A component for a liquid heating vessel, comprising the apparatus of any one of claims 24to64.
66. The component of claim 65, including a lid for the liquid heating vessel.
67. The component of claim 66, including a hinge for the lid.
68. The component of any one of claims 64 to 67, including a spout for the liquid heating vessel.
69. The component of any one of claims 64 to 68, including a handle for the liquid heating vessel.
70. A liquid vessel having a liquid reservoir and a capacitive liquid level sensor for sensing the liquid level within the reservoir, the sensor comprising a plurality of capacitor plates each extending in a vertical direction of the reservoir and making a capacitive coupling with liquid within the reservoir through a portion of the wall of the reservoir, the capacitor plates being mutually spaced apart around the circumference of the reservoir such that the combined capacitance measured through the capacitor plates is representative of the level or volume of liquid within the reservoir, substantially independently of the angle of tipping of the reservoir.
71. The vessel of claim 70, wherein the vessel has an outer wall outside the wall of the reservoir.
72. The vessel of claim 70 or 71, whereinthe vessel includes means for indicating the level or volume of liquid within the reservoir in response to the liquid level sensor.
73. The vessel of claim 72, wherein the means for indicating is substantially continuously variable.
74. The vessel of claim 72, wherein the means for indicating is responsive to one or more liquid level thresholds being exceeded.
75. A cordless electrical appliance comprising an appliance proper and a power base, the appliance having a component sealed therein by means of a seal arranged to provide an optical coupling between the appliance proper and the power base.
76. The appliance of claim 75, wherein the component comprises a cordless electrical connector.
77. The appliance of claim 76, wherein the seal is concentric with the cordless electrical connector.
78. The appliance of any one of claims 75 to 77, wherein the component is sealed within the appliance proper.
79. The appliance of any one of claims 75 to 78, including at least one an optical device optically coupled to the seal.
80. The appliance of claim 79, wherein the at least one optical device is located within the seal.
81. The appliance of claim 79 to 80, including a plurality of said optical devices mutually spaced apart in azimuthal position with respect to the optical coupling.
82. The appliance of claim 81, wherein the plurality of optical devices are evenly spaced apart.
83. The appliance of claim 81, wherein the plurality of optical devices are unevenly or asymmetrically spaced apart.
84. The appliance of any one of claims 81 to 83, wherein at least one of the plurality of optical devices is redundant, such that the optical coupling is operable if said redundant optical device is non-operable.
85. The appliance of any one of claims 75 to 84, including a light guide optically coupled with the seal.
86. The appliance of any one of claims 75 to 85, wherein the appliance proper includes an optical transmitter arranged to communicate through the seal to an optical receiver in the power base.
87. The appliance of claim 86, wherein the optical transmitter is arranged to communicate a sensed property of the appliance proper to the optical receiver.
88. The appliance of claim 87, wherein the power base is arranged to switch power to the appliance proper in response to said sensed property.
89. An electrical component having a seal for sealing the component within an appliance and/or power base, and optical communication means for optical communication through the seal.
90. The component of claim 89, comprising a cordless electrical connector.
91. A cordless electrical connector having an optically transmissive main moulding arranged to provide an optical coupling.
92. The appliance, component or connector of any one of claims 76 to 91, wherein the cordless electrical connector is a 3600 cordless connector.
93. The appliance, component or connector of claim 92, wherein the optical coupling is a 360° optical coupling.
94. A cordless electrical appliance comprising an appliance proper and a power base, wherein a first, unidirectional signalling link is provided between the appliance proper and the power base, and a second, discrete signalling link is provided between the appliance proper and the power base.
95. The appliance of claim 94, wherein the second signalling link is unidirectional, in a direction opposite to that of the first signalling link.
96. The appliance of claim 94 or 95, wherein one of said first and second signalling links is an optical signalling link.
97. The appliance of any one of claims 94 to 96, wherein one of said first and second signalling links is an electrical signalling link.
98. The appliance of claim 97, wherein said electrical signalling link is through one or more power terminals of a cordless electrical connection between the appliance proper and the base.
99. A user interface for a liquid heating appliance, the interface having a single user actuator for selecting at least first and second parameter settings for the appliance.

Claims are truncated...