GB2311716A - Kettle with visual indicator reactive to temperature - Google Patents

Abstract

A kettle 10 comprises a thermally insulated housing 11, a heating element in its base 17 and an indicator 51 providing visual indication of when the contents of the kettle exceed a specified temperature. Preferably the indicator consists of a heat responsive strip 51 which changes colour, eg from green to black, at the specified temperature. The visual indicator may be formed on a contents level gauge 50, the gauge consisting of a dial 52 coupled to a float (54, Fig 6) within the kettle, the float being attached to and rotating around a helical strip (53, Fig 6) and thus rotating the dial on the gauge. The kettle may be located upon an electrical pod 20, the pod having an upstanding boss (21, Fig 3) connecting with the kettle, the shape of the pod and kettle being such that the kettle receives electricity through the pod regardless of the orientation of the kettle on the pod. The kettle housing may be double walled with an air space between the walls so as to improve thermal insulation.

Description

Kettle This invention relates to a domestic kettle and in particular relates to an electric kettle with energy saving characteristics.

Electric kettles prove a very popular means of boiling water for use in the preparation of beverages such as tea and coffee. One problem with electric kettles is that they are often not thermally insulated, which means that once the water is boiled there is rapid loss of heat through the wall of the kettle. Thus, with ongoing use there is often a need to re-turn on the kettle to re-boil its contents.

Many electric kettles have a plug-in lead that has to be removed to allow the kettle to be filled with water. The placing of an electrical lead in close proximity to water is inherently dangerous. Most kettles provide no indication of the temperature of the kettle's contents. It is these disadvantages that have brought about the present invention.

According to the present invention there is provided a kettle comprising a thermally insulated housing with an electrical heating element positioned in the base characterised in that the exterior of the kettle carries an indicator that provides a visual indication when the contents exceed a predetermined temperature.

An embodiment of the present invention will now be described by way of example only with reference to the accompanying drawings in which: Figures 1 and 2 are perspective views of the kettle taken from opposite sides, Figures 3 and 4 are perspective views of the kettle with the kettle body removed from an electrical pod, Figure 5 is a plan view of the kettle, Figure 6 is a sectional view taken along the lines 6-6 of Figure 5, and Figure 7 is a sectional view taken along the lines 7-7 of Figure 5.

The kettle 10 illustrated in the accompanying drawings is molded in plastics, and comprises a body 11, having a centrally positioned handle 12, an open top 13 and pouring spout 14. A cover 15 sits across the open top and across an aperture 16 in the pouring spout 14. The base 17 of the kettle 10 is arranged to be supported on an electrical pod 20. As shown in Figures 3 and 4 the electrical pod 20 is of circular cross-section with a centrally positioned upstanding boss 21. The pod 20 has a cable 22 that can be plugged into a source of mains electricity and the current is coupled to the base 17 of the kettle body through the upstanding boss 21 which is arranged to seat in electrical contact with a suitably profiled recess 25 in the base 17 of the kettle as shown in Figure 3. The electrical pod 20 and kettle 10 are designed so that power flows to the kettle no matter which way the kettle is placed on the pod 20. Thus it is a simple matter to remove and re-attach the kettle to the pod and ensure flow of power.

The kettle body 11 has an outer cylindrical casing 30 and an inner walled structure 31 that forms the interior 32 of the kettle. The outer wall 30 has a outwardly projecting downward skirt 34 that houses the recess 25 for the boss 21 of the pod 20 and includes a support plate 35 that extends across the base 17 of the body to facilitate stable seating of the kettle on the pod 20. The twin walled structure of the kettle body provides an air gap 36 between the inner and outer walls 31 and 32 to improve the insulation of the kettle. The interior 32 of the kettle houses an electrical element 40 in the form of a coil that is in electrical contact with the electrical supply through the pod 20 via the interconnection between the boss 21 and the recess 25 of the pod and kettle base respectively. The electrical coil 40 is positioned in the base of the interior 32 of the kettle to ensure that it is always submerged in water when in use.

The handle 12 of the kettle is positioned centrally of the cylindrical wall and comprises inner and outer arcuate surfaces 45, 46 profiled to fit comfortably into the hand of the user. The outer surface 46 of the handle supports an on/off switch 48 that is a fulcrum type of switch to pivot downwardly into the 'on' position. There is also a small warning light 49 that is illuminated when the power is 'on'. The kettle also incorporates an automatic cut-out that is activated by the generation of steam to switch the kettle off as soon as it boils. The operation of the switch and the automatic cut-out are considered to be well known to those skilled in this art and are not described in detail in this specification.

Adjacent the top of the outer surface 46 of the handle is a contents gauge 50 in the form of an arcuate strip 51 of plastics that supports a centrally positioned dial 52 that is rotatable from a left hand position which designates that the kettle is empty to a right hand position which designates that the kettle is full. The dial 52 is driven by a helical metallic strip 53 that is mounted vertically against the internal wall 31 of the kettle as shown in Figure 6, and is caused to rotate as an arcuate float 54 moves as the level of the water of the kettle changes. The float 54 is made of hollow foam plastics and floats on the top of the surface of the water to move from the base position shown in Figure 6 when the kettle is empty to an upper position shown in dotted profile where the kettle is full. Vertical movement of the float 54 causes the helical strip 53 to axially rotate to thus in turn rotate the dial 52 on the outer surface of the handle.

The arcuate plastics strip 51 that supports the dial 52 is manufactured of a heat responsive material so that when the contents of the kettle reach a temperature of above 860C the colour of the arcuate strip 51 turns from green to black. It is considered that in the making of tea or coffee the water temperature should be at least 860C and thus as long as the temperature indicator is coloured black the user of the kettle knows that the water is at the required temperature and thus there is no need to re-boil the water. This feature, coupled with the fact that the kettle is an insulated plastic structure means that the kettle offers substantial energy savings in that there is no need to constantly re-heat the contents as is usual in more conventional kettles. The positioning of the level gauge 50 also provides a ready indication of the contents of the kettle whichever hand is used to pick up the kettle.

This is viewed as an advantage over other kettles where the contents can only be accurately ascertained by removing the lid which can be dangerous in that an escape of steam can cause scalding, or if the portion of the side wall of the kettle is transparent to show the contents of the kettle this can often only be viewed when the kettle is picked up with either the left or right hand.

Other features of the kettle relate to the design of the pouring spout 14 which is sufficiently wide in plan as shown in Figure 5 to allow the kettle to be filled via the spout 14 without the necessity of removing the cover 15.

The cover 15 also includes a downwardly extending perforated plastics filter 56 that extends across the spout 14 to ensure that debris within the kettle does not escape with the contents. The filter 16 also assists in ensuring that the hot air above the water in the kettle does escape via the spout 14 thus improving the heat retention capacity of the kettle.

Although the preferred embodiment of the kettle comprises a body that seats onto a 3600 pod it is understood that the kettle could be of the kind to have a retractable plug that fits into the base of the kettle.

The kettle described above is easy to use, provides a number of important safety features and in particular, is energy efficient. The twin walled insulated construction together with a readily visible temperature indicator allows the kettle to be boiled once and then left in a free standing mode without the need to constantly re-boil the contents.

Claims (10)

CLAIMS.

1. A kettle comprising a thermally insulated housing with an electrical heating element positioned in the base characterised in that the exterior of the kettle carries an indicator that provides a visual indication when the contents exceed a predetermined temperature.

2. The kettle according to claim 1 wherein a strip of heat responsive material is positioned in proximity to the contents of the kettle, the heat responsive material changing colour when the temperature of the contents exceeds a predetermined threshold.

3. The kettle according to either claim 1 or claim 2 wherein the kettle body supports a gauge that provides a visual indication of the level of the contents of the kettle.

4. The kettle according to claim 3 wherein the gauge comprises a dial that is coupled to a float within the kettle whereby the dial rotates independent of the position of the float.

5. The kettle according to claim 4 wherein the float is coupled to a helical strip so that as the float moves up and down the helical strip, the strip rotates to rotate the dial.

6. The kettle according to any one of the preceding claims wherein the kettle is molded in plastics and has a centrally positioned handle on one side opposed to a pouring spout on the other, a removable cover covering the open mouth of the kettle body.

7. The kettle according to any one of the preceding claims wherein the kettle housing is twin walled with an air space between the walls.

8. The kettle according to claim 6 wherein the handle supports an arcuate strip of heat sensitive plastics, the dial being mounted centrally over the strip.

9. The kettle according to any one of the preceding claims wherein the base of the kettle is adapted to be coupled to an electrical pod, the electrical pod having an upstanding boss which is arranged to be in electrical connection with a recess and the base of the kettle so that positioning the kettle body onto the pod causes flow of electricity from the pod to the kettle.

10. A kettle substantially as described with reference to the accompanying drawings.