WO2008050169A1

WO2008050169A1 - Immersion water heater particularly for preparing hot beverages and the like

Info

Publication number: WO2008050169A1
Application number: PCT/IB2006/002959
Authority: WO
Inventors: Michael Von Seidel
Original assignee: Individual
Current assignee: Individual
Priority date: 2006-10-22
Filing date: 2006-10-22
Publication date: 2008-05-02
Anticipated expiration: 2009-04-22

Abstract

An immersion heater assembly (1 ) is provided comprising an immersion heating element (4) configured for introduction into an open topped mug (3) or the like and a carrier (5) for supporting the heating element (4) in a generally- upright operative orientation with the carrier uppermost. An electric circuit for operatively supplying electrical energy to the heating element (4) includes a switch (6) for opening and closing the electric circuit, and temperature activated means (7) for causing opening of the electric circuit when a predetermined temperature of at least 75 degrees centigrade and less than the boiling point of water is detected in a body of liquid in which the heating section of the element is located. Various arrangements and configurations of immersion heater assemblies are provided including separate stands (15,2S) for holding them in their operative positions.

Description

IMMERSION WATER HEATER PARTICULARLY FOR PREPARING HOT

BEVERAGES AND THE LIKE

FIELD OF THE INVENTION

This invention relates to an immersion water heater that is particularly suitable for preparing hot beverages and the like and that is of the type having a heating element that operatively extends downwards into a liquid in a container from the top of the liquid. Such an immersion heater may be used for heating water contained in a cup, mug or other suitable vessel (herein referred to collectively as a mug) to enable a beverage such as tea or coffee, soup or some other liquid product (collectively termed beverage herein) to be made in a small quantity, typically a single mug thereof.

It is to be noted that in this specification the "boiling point of water" is used as a definitive term and is relevant in determining the scope of the invention. As the boiling point of water decreases with increasing altitude, and is therefore somewhat variable, some of the preset temperatures mentioned may be higher than the boiling point of water at such high altitudes and the yardstick of the boiling point of water is intended to override any mention of specific temperatures higher than the boiling point at any particular high altitudes. Applicant is, however, aware that the vast majority of people live at altitudes below about 8000 feet (2438 metres) above sea level at which the boiling point of water is approximately 92 degrees centigrade, and that about 97 percent of people live at altitudes of less than about 5000 feet (about 1524 metres) above sea level where the boiling point of water is about 95 degrees centigrade. BACKGROUND TO THE INVENTION

The most typical way in which a single mug of beverage is prepared at a personal or domestic level is to boil a quantity of water in an electric kettle and then pour the required amount into the mug. This is accompanied by at least two disadvantages.

The first is that substantially more water is generally boiled than is required to fill a single mug. The second is that the boiling water that is poured into the mug immediately gives up heat to the mug itself thereby going through an initial rapid cooling from boiling point the a temperature that may be about 5 to 20 degrees centigrade lower, depending on the nature, size and heat capacity of the mug and the quantity of boiling water introduced into it.

The first of these disadvantages simply translates into a waste of the electrical energy that was used to boil water in excess of that required for the single mug and, for that matter, the electrical energy spent in heating the kettle itself. The amount of excess water boiled may be as much as one, two, or even more times the amount of water actually used. Accordingly, up to two, three or more times the amount of the electrical energy that would have been required to boil a single mug-full of water may be consumed. A contributing factor to this disadvantage is that it is often not practical or feasible to boil a single mug-full of water in a kettle due to the minimum water level requirement that is often already in excess of the amount of water required for the single mug. Taking into account the very many single mugs of beverage that are generally made in any electrical supply region, the amount of wasted electrical energy must be considerable.

This situation is exacerbated in that most electric kettles are fitted with a heat operated automatic switch that serves to turn the kettle off when the water boils, and wherein a bimetallic component of the switch is heated by steam generated by the boiling activity. Whilst some of these switches require only a small amount of steam to be generated, others require substantially more to be generated before the switch is activated. It appears to applicant that the smaller the amount of water boiled in a kettle the more steam must often be generated in order to activate the switch. All of the electrical energy consumed to generate that steam is also wasted. Indeed the use of electric kettles, in applicant's view, is a highly inefficient way of heating water for use in small quantities for producing beverages.

The second disadvantage indicated above may mean that, at least in instances in which considerable heat is extracted by the mug itself with a corresponding rapid drop in temperature of the water, infusion, hydration or dissolution that is necessary to produce the required beverage may be inhibited, insufficient or incomplete. This effect may be more significant at high altitudes where the boiling point of water is depressed below 100 degrees centigrade.

All of these disadvantages can be overcome, at least to some extent, by the careful use of the simple portable immersion heater of the type having a handle fitted to a cold end of an electric heating element and a hook fixed to the handle whereby the heater can be suspended on the rim of a mug with a hot coil of the heating element immersed in the contents of the mug.

However, such an immersion heater is not generally convenient and is usually only used by persons travelling or otherwise away from their usual amenities as a convenient way of making a beverage at any stopover or transit place.

As regards the heating of small quantities of water or beverage, the prior art shows that various proposals have been put forward primarily for the purpose of providing convenience and facility for travellers at stopover points. Most relevant to the present invention, as far as applicant can determine, is the device described and illustrated in United States patent no 3,121 ,783. That patent proposes an immersion heater carried by a swing arm to allow for its introduction into a container of water or beverage from the top and its retraction when the water has boiled or the beverage has been heated adequately. A thermostatic switch is provided for interrupting the flow of electrical energy to the heating coil when a required predetermined temperature is reached or when heating has been effected for a predetermined period of time. The flow of current to the heating coil is enabled or interrupted according to the position of the heating element, namely, when it is in its lowermost terminal operative position the circuit is closed and when it is retracted to a raised inoperative position the circuit is open. It must be taken that either water is heated to boiling point or beverage is heated to a drinking temperature generally in the range of about 50 to 60 degrees centigrade. No specific temperatures are mentioned, nor is any aim of saving electricity. The device described appears to be simply an appliance of convenience for use by travellers. Applicant is unaware of whether or not such an item was made available commercially.

OBJECT OF THE INVENTION

It is an object of this invention to provide an immersion heater of the general type indicated above that is more conducive to general use with the aim of achieving at least some of the accompanying benefits indicated above, in particular, at least some saving in electrical energy consumption.

SUMMARY OF THE INVENTION

In accordance with one aspect of the invention there is provided an immersion heater assembly comprising an immersion heating element having an operatively lower heating section configured for introduction into an open topped mug or the like and cold sections communicating therewith wherein the cold sections have attached thereto a carrier for supporting the heating element in a generally upright operative orientation with the carrier uppermost, an electric circuit for operatively supplying electrical energy to the heating element, a switch in the electric circuit for opening and closing the electric circuit, and temperature activated means for causing opening of the electric circuit when a predetermined temperature is detected in a body of liquid in which the heating section of the element is located, the immersion heater assembly being characterised in that the temperature activated means is operative to cause opening of the electric circuit to the heating element, in use, when a temperature of at least 75 degrees centigrade and less than the boiling point of water is detected in a body of liquid in which the heating section of the element is located.

Further features of this aspect of the invention provide for the temperature at which the temperature activated means is adapted to cause opening of the electric circuit to be in the range of from about 80 to about 95 degrees centigrade; preferably from about 85 to 95 degrees centigrade and generally at about 90 degrees centigrade; for the switch to be manually closable with the temperature activated means operatively causing opening of the switch when the required temperature is reached; and for the temperature activated means either to be adapted for immersion in a body of liquid simultaneously with immersion of the heating section of the heating element in the manner of a probe or, alternatively, for the temperature activated means to have associated therewith a thermal sensor adapted for immersion in such body of liquid.

Still further features of this aspect of the invention provide for the carrier to assume the form of a base plate or chassis (hereinafter referred to as a base irrespective of its construction) extending transversely to the straight sections of the heating element and wherein the base preferably carries the temperature activated means that is either embodied in a probe extending from the base to terminate in the general region of the heating section of the heating element or, alternatively, is fixed to the base and is electrically connected to a probe in which a temperature sensor is present; for the base to have a cover forming an enclosure therewith for the electrical components of the assembly; for the manually closable switch to be accessible externally of the cover; for the assembly to have means for indicating when the temperature activated means has caused opening of the switch; for an electrical supply cord for connection to an electrical supply outlet to extend directly from the enclosure; and for support means to be provided for supporting the base relative to a supporting worktop with the heating section of the heating element at a predetermined height from the worktop in the operative position.

The support means for the base could assume one of many different types but will generally be divided into two categories, namely, support means that render the immersion heater assembly free standing on a supporting worktop, such as three legs extending from the base or cover so as to be located on the outside of a mug in which liquid is to be heated, and support means that involve the use of a separate stand with respect to which the immersion heater may either be loosely associated; or be held captive or retractable relative to the stand and movable between operative and inoperative positions.

The invention therefore also provides, as a second aspect of the invention, an immersion heater assembly comprising an immersion heating element having an operatively lower heating section configured for introduction into an open topped mug or the like and cold sections communicating therewith wherein the cold sections have attached thereto a base for operatively supporting the heating element in a generally upright operative orientation with the base uppermost, an electric circuit by way of which electrical energy is operatively supplied to the heating element, a switch in the electric circuit for opening and closing the electric circuit, and temperature activated means for causing opening of the electric circuit when a predetermined temperature is detected in a body of liquid in which the heating section of the element is located, the immersion heater assembly being characterised in that it has support means whereby it can be supported in a generally upright orientation in free standing manner on a worktop, independently of any mug in association with which it is to be used, and in that the base also supports said switch and temperature activated means for opening and closing the electric circuit.

In accordance with third aspect of the invention there is provided an immersion heater assembly comprising an immersion heating element having an operatively lower heating section configured for introduction into an open topped mug or the like and cold sections communicating therewith wherein the cold sections have attached thereto a carrier for supporting the heating element in a generally upright operative orientation with the carrier uppermost, an electric circuit for operatively supplying electrical energy to the heating element, a switch in the electric circuit for opening and closing the electric circuit, and temperature activated means for causing opening the electric circuit when a predetermined temperature is detected in a body of liquid in which the heating section of the element is located, the immersion heater assembly being characterised in that the electric circuit has terminals adapted to cooperate with cooperant terminals on a separate supporting stand to connect the immersion heater assembly with an electrical current supply in the operative position.

Further features of this aspect of the invention provide for the electric circuit terminals to be configured similarly to those of so-called cordless kettles to render the immersion heater assembly cordless in nature with the electrical energy supply communicating by way of the supporting stand.

The invention is also provides an appliance comprising an immersion heater assembly defined above as the third aspect of the invention in combination with a supporting stand wherein the stand and immersion heater assembly have cooperating contacts for connecting the electric circuit of the immersion heater assembly with an electrical power supply by way of the stand.

In accordance with a fourth aspect of the invention there is provided an immersion heater assembly comprising an immersion heating element having an operatively lower coiled heating section configured for introduction into an open topped mug or the like and generally straight sections that include cold sections extending away from the coiled heating section communicating therewith wherein the cold sections have attached thereto a carrier for operatively supporting the heating element in a generally upright orientation with the carrier uppermost, the immersion heater assembly being characterised in that the overall length of the immersion heating element is in excess of three times the outer diameter of the coiled heating section.

Preferably, the overall length of the immersion heating element is about three and a quarter to three and a half times the outer diameter of the coiled heating section and up to about four times.

In accordance with a fifth aspect of the invention there is provided an appliance characterised in that it comprises at least two independently operable immersion heater assemblies of the general nature defined above formed into a single appliance.

It is a feature of this invention that a modified kettle type of steam operated switch could be employed as the thermally operated switch with the addition of a small heating element that is associated with the bimetallic component of the switch. The small heating element would be connected into a control circuit including a thermally operated switch, typically in the form of a sensor within a probe arranged to supply a relatively low current electrical supply to the heating element once the required temperature is detected. The heating element could be a simple thermal resistor. Heating of the bimetallic component is thus achieved using the small heating element as a replacement for heating by means of steam.

In the alternative, it is envisaged that a heat conductive rod or tube may be arranged to conduct heat from the operatively lower region of the heating element to a position in the region of the carrier and the elevated temperature of the external end of the conductive rod or tube employed to operate a thermally operated switch such as a bimetallic disc type of switch. In such an instance the portion of the conductive rod or tube not generally immersed in liquid in use, would be heat insulated.

It is also within the scope of the invention that an electronic switch such as a triac could be employed for directly controlling the circuit to the heating element in which instance a temperature sensing probe would be employed to operate the triac.

In order that the above and other features of the invention may be more fully understood various different embodiment thereof will now be described with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:-

Figure 1 is a schematic side elevation illustrating one embodiment of the invention;

Figure 2 is a schematic front elevation thereof;

Figure 3 illustrates schematically an alternative basic configuration of immersion heating element; Figure 4 illustrates schematically, in exploded relationship, one simple embodiment of immersion heater assembly and an optional associated storage receptacle;

Figure 5 illustrates schematically an embodiment of the invention employing a separate immersion heater assembly and stand therefor;

Figure 6 illustrates an alternative stand assembly to that illustrated in Figure 5;

Figure 7 illustrates an embodiment of the invention similar to that illustrated in Figure 5 wherein the immersion heater assembly is held captive relative to its associated stand;

Figure 8 illustrates an embodiment of the invention in which the immersion heating element is vertically retractable;

Figure 9 illustrates schematically another embodiment of the invention in which the immersion heating element is retractable;

Figure 10 illustrates an appliance including two separate immersion heater assemblies; and,

Figure 11 is one arrangement of circuit diagram of an immersion heater assembly according to the invention.

DETAILED DESCRIPTION WITH REFERENCE TO THE DRAWINGS

Referring firstly to Figures 1 and 2 of the drawings, an immersion heater assembly according to the first aspect of the invention, generally indicated by numeral (1), comprises an immersion heating element having an operativeiy lower vertically coiled heating section (2) configured for introduction into an open topped mug (3) or the like and operativeiy generally upright cold sections (4) attached at their upper ends to a transverse baseplate (5) for supporting the heating element in a generally upright operative orientation.

In order to ensure that the coiled section is immersed in liquid, in use, irrespective of whether a tall and squat mug is being employed (both of which are illustrated in dotted lines (3)), the overall length of the heating element needs to be greater than currently available ones of which applicant is aware and, indeed, the overall length of the heating element is preferably about three and a half times the outer diameter of the coiled heating section. As a typical coiled heating section has an outer diameter of about 35 millimetres this proportion enables mugs having a height ranging from about 60 to about 130 millimetres to be used (with a suitable quantity of water therein).

It is to be mentioned that a generally vertically coiled heating section is described herein as applicant understands it to be the most convenient form from a manufacturing point of view. However, as may be appropriate, a generally horizontally coiled heating section (2a), as illustrated in Figure 3, may be preferable.

An electric circuit for operativeiy supplying electrical energy to the heating element comprises a manually closable switch (6) and temperature activated means embodied in a probe (7) for causing opening the electric circuit when a predetermined temperature is detected in a body of liquid in which the heating section of the element is located. As provided by the first aspect of the invention, the temperature activated means is adapted to cause opening of the electric circuit to the heating element at a temperature of less than the boiling point of water and preferably about 90 degrees centigrade. Of course, the physical location of the temperature activated means will need to be selected relative to the position of the coiled heating section in order to ensure that a representative temperature is detected and not that of a "hot spot" or "cold spot".

The manually closable switch can conveniently be operated by means of an elongate pushbutton (8) the outer surface of which can have a brightly coloured region that is exposed when the pushbutton is in its outwardly extending position corresponding to the switch being open, as shown in Figure 1 , and that is obscured when the pushbutton is in a depressed position corresponding to the switch being closed, as shown in Figure 2. It will thus be easy to observe when a switch that has been closed has opened after reaching the temperature. Of course, it is within the scope of the invention to include an indicator light (9) for indicating when the required temperature has been reached and the switch has opened.

Electrical energy is applied to the circuit described above, in this instance, by an electrical supply cord (10) connected directly to the immersion heater assembly. A cover (11) extending over the base forms an enclosure therewith for the electrical components of the assembly.

The above forms one embodiment of basic immersion heater assembly provided by the first aspect of the invention and it may be deployed for use in numerous different forms.

Thus, as illustrated in Figure 4, the base and cover assembly (12) could be provided with three equally angularly spaced legs (13) supporting the heater assembly directly on a worktop. This would probably be the most inexpensive and simplest form of the invention. As an accessory to this form, a receptacle (14) for receiving the heating element and probe may be provided for storage purposes in order to maintain an hygienic condition of the heating element. Alternatively, as illustrated in Figure 5, a separate stand (15) may be provided for supporting the immersion heater assembly (1) in position relative to a mug supporting platform (16) provided on the stand. This stand has a separate compartment (17) for storing the heating element and probe when not in use. In both of these positions the immersion heater assembly is to be supported on an elevated generally horizontal panel (18) with the heating element and probe extending through apertures (19) therefor.

Figure 5 also illustrates the instance in which an electrical supply cord (20) communicates with the stand that is provided with contacts (21) adjacent the aperture positioned over the platform for engagement by cooperating contacts (22) provided on the base of the immersion heater assembly. These contacts may, as indicated above, be configured similarly to those of so-called cordless kettles. In this instance the base would normally be provided with an on / off switch (23) (see Figure 11). This arrangement has the advantage that electrical energy can only be supplied to the heating element when it is in its operative position and at no other time, for example if the assembly is left lying on a worktop. Also, manipulation of the immersion heater assembly is not impaired in any way by the cord.

Figure 5 also illustrates the fact that upright side walls (24) of the stand can be provided with formations, in this instance horizontal dovetail formations (25), that enable a plurality of stands to be interconnected next to each other neatly for use in heating the contents of a plurality of mugs at the same time.

Figure 6 illustrates a simplified stand (26) of the type illustrated in Figure 5 in which the elevated panel has only one aperture (27) over the platform (28) and the storage compartment is defined by a removable receptacle that, in this instance, assumes the form of a jug (29). For storage purposes the jug (or other receptacle) would be present and act as the storage compartment; it can be removed to enable liquid in a mug to be heated; or it could be used to contain liquid to be heated for use elsewhere, for example for cooking purposes. The stand in this instance is much smaller than that illustrated in Figure 5.

Figure 7 illustrates an embodiment similar to that illustrated in Figure 5 and wherein the immersion heater assembly (1) is held captive relative to the stand (30) by means of a telescopically extensible column (31). In this instance the contacts can be embodied within the column to enable electrical energy to be supplied to the immersion heater assembly. The column is located centrally between the two apertures so that the immersion heater assembly can be raised; rotated through 180 degrees; and lowered into the other of the two possible positions.

Figure 8 illustrates an embodiment in which the immersion heating element (32) is vertically retractable relative to a housing (33) and also forms a stand.

Figure 9 illustrates schematically a retractable version in which the immersion heating element is movable between an elevated generally horizontal inoperative orientation indicated by numeral (34a), and a lowered generally vertical operative orientation indicated by numeral (34b). Numerous different mechanisms can be employed for guiding the heating element assembly for movement between the two positions. This arrangement has the benefit that a housing of lesser height will be required than in the event of the vertically retractable immersion heating element of Figure 8.

Figure 10 simply illustrates the fact that a single stand (35) may be produced to support a plurality of immersion heater assemblies (1).

It will be understood that numerous variations are possible to each of the different aspects of the invention without departing from the scope hereof.

Claims

CLAIMS:

1. An immersion heater assembly (1) comprising an immersion heating element having an operatively lower heating section (2) configured for introduction into an open topped mug (3) or the like and cold sections

(4) communicating therewith wherein the cold sections have attached thereto a carrier (5) for supporting the heating element in a generally upright operative orientation with the carrier uppermost, an electric circuit for operatively supplying electrical energy to the heating element, a switch (6) in the electric circuit for opening and closing the electric circuit, and temperature activated means (7) for causing opening of the electric circuit when a predetermined temperature is detected in a body of liquid in which the heating section of the element is located, the immersion heater assembly being characterised in that the temperature activated means is operative to cause opening of the electric circuit to the heating element, in use, when a temperature of at least 75 degrees centigrade and less than the boiling point of water is detected in a body of liquid in which the heating section of the element is located.

2. An immersion heater assembly as claimed in claim 1 in which the temperature at which the temperature activated means is adapted to cause opening of the electric circuit is in the range of from about 85 to about 95 degrees centigrade.

3. An immersion heater assembly as claimed in either one of the preceding claims in which the switch is manually closable with the temperature activated means operatively causing opening of the switch when the required temperature is reached.

4. An immersion heater assembly as claimed in any one of the preceding claims in which the carrier assumes the form of a base extending transversely to the straight sections of the heating element and wherein the base carries the temperature activated means that includes a probe extending from the base to terminate in the general region of the heating section of the heating element.

5. An immersion heater assembly comprising an immersion heating element having an operatively lower heating section configured for introduction into an open topped mug or the like and cold sections communicating therewith wherein the cold sections have attached thereto a base for operatively supporting the heating element in a generally upright operative orientation with the base uppermost, an electric circuit by way of which electrical energy is operatively supplied to the heating element, a switch in the electric circuit for opening and closing the electric circuit, and temperature activated means for causing opening of the electric circuit when a predetermined temperature is detected in a body of liquid in which the heating section of the element is located, the immersion heater assembly being characterised in that it has support means (13) whereby it can be supported in a generally upright orientation in free standing manner on a worktop, independently of any mug in association with which it is to be used, and in that the base also supports said switch and temperature activated means for opening and closing the electric circuit.

6. An immersion heating element having an operatively lower heating section configured for introduction into an open topped mug or the like and cold sections communicating therewith wherein the cold sections have attached thereto a carrier for supporting the heating element in a generally upright operative orientation with the carrier uppermost, an electric circuit for operatively supplying electrical energy to the heating element, a switch in the electric circuit for opening and closing the electric circuit, and temperature activated means for causing opening of the electric circuit when a predetermined temperature is detected in a body of liquid in which the heating section of the element is located, the immersion heater assembly being characterised in that the electric circuit has terminals (22) adapted to cooperate with cooperant terminals (23) on a separate supporting stand (15, 26) to connect the immersion heater assembly with an electrical current supply in the operative position.

7. An appliance characterised in that it comprises an immersion heater assembly as claimed in claim 6 in combination with a supporting stand wherein the stand and immersion heater assembly have cooperating contacts for connecting the electric circuit of the immersion heater assembly with an electrical power supply by way of the stand.

8. An immersion heater assembly comprising an immersion heating element having an operatively lower coiled heating section configured for introduction into an open topped mug or the like and generally straight sections that include cold sections extending away from the coiled heating section communicating therewith wherein the cold sections have attached thereto a carrier for operatively supporting the heating element in a generally upright orientation with the carrier uppermost, the immersion heater assembly being characterised in that the overall length of the immersion heating element is in excess of three times the outer diameter of the coiled heating section.

9. An immersion heater assembly as claimed in claim 9 in which the overall length of the immersion heating element is from three and a quarter times to about four times the outer diameter of the coiled heating section.

10. An appliance characterised in that it comprises at least two independently operable immersion heater assemblies as claimed in any one of claims 1 to 4 or 6 formed into a single appliance.