GB2520975A

GB2520975A - Spill-proof liquid heating vessels

Info

Publication number: GB2520975A
Application number: GB1321501.7A
Authority: GB
Inventors: Andrew Hewins; Nicholas Gibbs; Andrew Winstanley
Original assignee: Strix Ltd
Current assignee: Strix Ltd
Priority date: 2013-12-05
Filing date: 2013-12-05
Publication date: 2015-06-10
Also published as: JP3189742U; KR20150002255U; KR200485448Y1; GB201321501D0; CN203709810U

Abstract

A sealing mechanism 14 is disclosed for a substantially vertical steam tube 12 of a liquid heating vessel. The sealing mechanism comprises connection means for connecting the sealing mechanism to the steam tube and a weighted member or pendulum 16, mounted for pivotal movement relative to the connection means. The weighted member comprises an opening 22 which is in alignment with an opening in the connection means to provide a passage to the steam tube when the liquid heating vessel 2 is substantially vertical, wherein said opening in the weighted member moves out of alignment with the opening in the connection means when the weighted member pivots as a result of the kettle being tilted or knocked over. The sealing mechanism may also comprise one or more pads for closing the opening in the connection means.

Description

SPILL-PROOF LIQUID HEATING VESSELS

This application relates to liquid heating vessels, in particular kettles, which remain substantially safe from spillage even when they are accidentally knocked over.

Kettles are used worldwide to boil water, for example for use in making tea.

However, as kettles become more lightweight and portable, they are also more likely to be displaced, for example by knocking them over. Overturning a kettle which is currently or recently in use can cause hot water to be poured out, creating a health and safety hazard. It is therefore desirable to have safety measures to prevent water pouring from an overturned kettle. This desire is particularly prevalent in countries where kettles are used on the floor, for example during the serving of tea in some parts of the world.

In order to be classified as spill-proof, a device must typically lose less than 50 ml of liquid in 10 seconds when tipped over. By measuring the water leakage over this time, the level of spill-proofing can be easily determined. In order to reduce water spillage, a number of different methods can be used, ensuring that any gaps or holes on the kettle have been sealed, either due to manufacturing methods or by adding extra mechanisms to close necessary holes e.g. the lid and spout. For example, the spout may be held in a closed position by default, and only opened when water needs to be poured out. This can help to reduce the chance of water spillage if the kettle is overturned.

Liquid heating vessels which are designed to boil water will typically have a steam-sensitive switch mechanism to switch off a heater in the vessel once the water has boiled. The steam-sensitive switch is normally located outside the main chamber of vessel which holds the water and thus a steam tube is necessary to convey steam from the main water chamber to the steam switch. Such a steam-tube thus represents a possible escape path for water if the vessel is tipped over and so must also be sealed if a vessel is to be made spill-proof.

When viewed from a first aspect, this invention provides a sealing mechanism for a substantially vertical steam tube of a liquid heating vessel, the sealing mechanism comprising connection means for connecting the sealing mechanism to the steam tube and a weighted member mounted for pivotal movement relative to the connection means, the weighted member comprising an opening which is in alignment with an opening in the connection means to provide a passage to the steam tube when the liquid heating vessel is substantially vertical, wherein said opening in the weighted member moves out of alignment with the opening in the connection means when the weighted member pivots as a result of the liquid heating vessel being displaced from vertical.

Thus it can be seen that the weighted member acts as a pendulum, moving with the orientation of the vessel. As a result of its pivotal mounting the weighted member will maintain an approximately vertical orientation, causing it to move relative to the steam tube when the vessel is tipped over. By providing an opening in the weighted member which is in alignment with an opening in the connection means to provide a passage to the steam tube while the vessel is vertical, the vessel can operate as normal, allowing steam from the heating chamber to pass through the steam tube to a steam switch. However, if the vessel is displaced from vertical, the weighted member pivots relative to the steam tube, closing the steam tube by moving the openings out of alignment and preventing water from entering the steam tube and so leaking out of the vessel while it is overturned.

The steam tube may be used to convey steam from the main body of a liquid heating vessel to a steam sensor. This sensor may take any form, e.g. comprising a snap-acting bimetal.

In a set of embodiments, the sealing mechanism is designed for permanent connection to the steam tube. The connection means might therefore comprise part of the sealing device over-moulded onto, or otherwise bonded to, the steam tube. However, in an alternative set of embodiments, the sealing mechanism is removably connected to the steam tube. For example it could be screwed, snap-fitted or simply friction-fitted onto the end of a steam tube. In either case by fitting to the end of a steam tube, the sealing mechanism described herein can easily be added to existing designs of vessel without re-tooling or any other significant re-engineering being necessary.

The connection means may be resilient -e.g. formed from rubber, such that it can be easily fitted to the steam tube.

The weighted member may be made from or comprise metal. In a set of embodiments it comprises a metal weight encased in plastic.

In a set of embodiments, the opening in the weighted member has the same shape as the opening in the connection means providing passage to the steam tube. For a steam tube with a circular cross-section, the opening in the weighted member may have substantially the same diameter as the steam tube. This allows the steam tube to be closed quickly when overturning occurs, as any rotation of the weighted member begins to close the steam tube. This will therefore ensure that by the time the vessel reaches an angle at which water could begin to pour into the tube, the steam tube has been closed off sufficiently.

In a set of embodiments, the weighted member comprises one or more pads for closing the opening in the connection means. These pads may be arranged around the opening in the weighted member such that when the vessel is overturned the movement of the weighted member brings the pad or one of the pads into contact with the connection means to engage over its opening. In a set of embodiments there are two pads, arranged on either side of the opening in the weighted member.

In a set of embodiments, the weighted member comprises a cover spaced from and over the opening. This may provide a barrier to prevent liquid entering the steam tube directly, either during filling of the vessel or due to dripping of condensation from the lid.

Some embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which: Fig. 1 shows an exemplary kettle with which the invention may be used; Fig. 2 shows the internal design of the kettle of Fig. 1; Fig. 3 shows a sealing device in accordance with the invention; Fig. 4 shows a cross-section through the sealing device arrangement; Fig. 5 shows the upper portion of the sealing device of Fig. 3; Fig. 6 shows the sealing device arrangement when the kettle has overturned; Fig. 7 shows a cross section of the arrangement of Fig. 6; and Fig. 8 shows an alternative embodiment of the invention in which an alternative sealing device is used.

Fig. 1 shows an exemplary liquid heating vessel in the form of a kettle 2 with which a sealing device in accordance with the invention may be used. The kettle 2 has a substantially cylindrical body 4 with a rounded lid 6. A handle 8 extends rearwardly from the top of the body 4, near the connection to the lid 6. On the opposite side to the handle 8 is a spout 10, from which liquid can be poured.

Fig. 2 shows a cross-section through the kettle 2. Inside the main body 4 of the kettle, there is a steam tube 12. This steam tube 12 is connected at one end to a space containing a steam switch 13, which switches off the heater of the kettle 2 when water has boiled. At the other end of the steam tube 12 is mounted a sealing device 14 which will be described below. A further sealing device 16 can also be found on the inside of the spout 10, preventing water from pouring out of it in the event of oveiturning.

The sealing device 14 can be seen in more detail in Figs. 3 and 4. The sealing device 14 takes the form of a pendulum, with weights 16 hanging either side of the steam tube 12. However, in alternative embodiments there may be only one weight 16. These weights are suspended by a yoke arrangement 18 mounted on a pivot 20. An opening 22 is defined in the top of the yoke 18 which in the normal orientation shown in Figs. 3 and 4, is aligned with a corresponding opening in a bung 24 which acts as a connecting means connecting the sealing device 24 to the top of the steam tube 12. This allows steam to enter the steam tube 12 under normal circumstances.

Fig. 5 shows the upper portion of the sealing device 14 in more detail. From this it may be seen that the pivot 20 is provided by the bung 24, which in this embodiment is a friction fit connection to the steani tube 12. This ensures that the weights 16 and yoke 18 can pivot about the top of the steam tube 12. Above the opening 22 is a cover 26. This may prevent water from falling directly into the steam tube 12 during normal use.

Figs. 6 and 7 show what happens when the kettle 2 is accidentally knocked over.

The steam tube 12 is fixed relative to the main body 4 of the kettle and so is now tilted from the vertical. As a result the sealing device 14 has pivoted about the pivot 20 such that the opening 22 is no longer in line with the opening in the end of the bung 24 in the steam tube 12. This can be seen clearly in Fig. 7, where the cross-sectional view shows the steam tube 12 is closed off by the yoke 18. The yoke 18 can rotate through an angle of 60 to 700 before being stopped by the bung 24 in the steam tube 12 (as can be seen in Fig. 7, where the yoke 18 has reached its maximum angle of rotation). This prevents water from entering the steam tube 12, and then being able to leak out from there. Together with other devices such as spout seals, the kettle is then prevented from unintentionally leaking any significant amount of water.

Fig. 8 shows an alternative embodiment in which two pads 28 are used to close the opening in the top of the bung 24. These pads 28 are arranged adjacent to the opening in the yoke. If the kettle 2 is accidentally knocked over, the sealing device 14' will pivot relative to the steam tube 12, causing one of the pads 28 to move into alignment with the opening in the end of the bung 24' in the steam tube. The pads 28 are shaped such that the steam tube is sufficiently closed when the kettle 2 is overturned to prevent too much leakage. The shape of the pads 28 is also used to prevent over-rotation of the sealing device 14'. By using two pads 28, friction between the pads 28 and the bung 24' is reduced in comparison with using the yoke 18 for sealing. This is because the pads 28 are not permanently in contact with the opening in the bung 24'. In addition, there is only edge contact between the bung 24' and the pads 28, minimising the chance of sticking when the kettle 2 is returned to vertical. This provides sufficient contact for closure of the steam tube, while reducing the chance of the steam tube gefting jammed in a closed position, causing problems for the operation of the kettle.

Claims

Claims 1. A sealing mechanism for a substantially vertical steam tube of a liquid heating vessel, the sealing mechanism comprising connection means for connecting the sealing mechanism to the steam tube and a weighted member mounted for pivotal movement relative to the connection means, the weighted member comprising an opening which is in alignment with an opening in the connection means to provide a passage to the steam tube when the liquid heating vessel is substantially vertical, wherein said opening in the weighted member moves out of alignment with the opening in the connection means when the weighted member pivots as a result of the liquid heating vessel being displaced from vertical.
2. The sealing mechanism as claimed in claim 1 wherein the steam tube is used to convey steam from a main body of the liquid heating vessel to a steam sensor.
3. The sealing mechanism as claimed in claim 2 wherein the sensor comprises a snap-acting bimetal.
4. The sealing mechanism as claimed in any preceding claim wherein the sealing mechanism is permanently connected to the steam tube.
5. The sealing mechanism as claimed in any preceding claim wherein the sealing mechanism is removably connected to the steam tube.
6. The sealing mechanism as claimed in any preceding claim wherein connection means is resilient.
7. The sealing mechanism as claimed in any preceding claim wherein the weighted member comprises a metal weight encased in plastic.
8. The sealing mechanism as claimed in any preceding claim wherein the opening in the weighted member has the same shape as the opening in the connection means to provide the passage to the steam tube.
9. The sealing mechanism as claimed in any preceding claim wherein the weighted member comprises one or more pads for closing the opening in the connection means.
10. The sealing mechanism as claimed in claim 9, comprising two pads, arranged on either side of the opening in the weighted member.
11. The sealing mechanism as claimed in any preceding claim wherein the weighted member comprises a cover spaced from and over the opening in the weighted member. r r r