GB2328143A

GB2328143A - A domestic electrical appliance removable from a base

Info

Publication number: GB2328143A
Application number: GB9717311A
Authority: GB
Inventors: Darren Prosser; William Porter
Original assignee: Kenwood Marks Ltd
Current assignee: Kenwood Marks Ltd
Priority date: 1997-08-16
Filing date: 1997-08-16
Publication date: 1999-02-17
Anticipated expiration: 2017-08-16
Also published as: GB2328143B; GB9717311D0

Abstract

The invention relates to so called "cordless" domestic electrical appliances, such as jug kettles,in which the appliance 1 itself is separable from a base unit 3 and can rotate freely relative to its base about the axis of co-operative parts 4,5 of a coaxial connector. The invention provides means whereby a functional parameter of the appliance differs and/or is implemented differently in dependence upon its rotational position relative to the base. In one example, the appliance is a kettle which carries a circuit arrangement 6 capable of giving an audible warning when the kettle's contents have boiled, and the operation of that circuit arrangement is enabled or disabled in dependence upon the rotational position Magnets 8 and suitably responsive reed switches 7 may be used to effect the selective enabling and disabling. Alternatively, power settings or cut-off temperatures may be varied by the rotational position, or an electric descaling device may be enabled. The different positions may be indicated by visual or tactile means.

Description

Domestic Electrical Appliances This invention relates to domestic electrical appliances, and it relates in particular to kitchen appliances such as (for example) jug kettles.

It is well known to provide domestic electrical appliances in which the appliance itself is separable from a base unit that may, for example be attached to a source of electrical power for the appliance. In such cases, it is common to refer to the appliance as "cordless" since, although the base unit is connected to the electricity supply by means of a power cord, or cable, the appliance is free of the cord when separated from the base unit. In the case of a jug kettle, for example, this permits of convenient, single-handed usage of the appliance for pouring out its contents once they have been raised to the desired temperature. The user does not have to trail the cord or disengage the cord from the appliance.

It is axiomatic that the act of disengagement of the appliance from its base must be quick and easy to achieve, preferably by the user doing no more than lifting the appliance off of the base, whilst at the same time ensuring reliable, positive and safe electrical interconnection between the appliance and the base. The manufacturers of such bases have developed various forms of base/appliance interconnect to meet the above objectives, and a form that has become increasingly popular in recent years is the socalled 360 degree base described, for example, in International patent application No.

PCT/GB94/02010 (publication No. WO 95/08204), the content of which is incorporated herein by reference. In essence, the base and appliance carry co-operative parts of a three-terminal coaxial connector that permits the appliance to be placed upon or removed from the base at any rotational angle with respect to the base (in a plane intersected substantially orthogonally by the connector/appliance axis). This has proved to be effective and popular in use.

This invention is particularly concerned with appliance/base configurations of the general kind described above in the sense that it relates to such configurations as permit relative rotation through a significant angle (preferably though not necessarily 360 degrees) between the appliance and the base, but it is to be understood that it is not limited to configurations in which the base is used solely to supply power to the appliance, and provides a new operational principle, namely the provision of means whereby a functional parameter of the appliance differs and/or is implemented differently in dependence upon its rotational position relative to the base.

According to the invention there is provided a domestic electrical appliance, a base for said appliance, means permitting relative rotation between said appliance and said base, and means responsive to the rotational position of said appliance relative to said base to cause said appliance to operate or function differently at one such relative rotational position, or range of positions, as compared with the operation or function of said appliance at at least one other such relative rotational position or range of positions.

In order that the invention may be clearly understood and readily carried into effect, one embodiment thereof will now be described by way of example only, with reference to the accompanying drawings of which: Figure 1 shows in part cross-sectional side elevation a jug kettle/base configuration in accordance with one example of the present invention, and Figure 2 shows a section on arrows AA of the configuration of Figure 1.

Referring now to the drawings, ajug kettle shown in outline at 1 contains inter alia, as is known, a plate 2 in its base which supports a heating element which is not shown in detail, as it could take any of a number of forms, but is generally indicated at 2a. The appliance 1 is associated with a power base 3 to which it is releasably coupled, so that it can be readily lifted therefrom, and so as to be free to rotate thereon as described hereinbefore, and as described in more detail in the aforementioned international patent application. The coaxial connector components, carried in part by the appliance 1 and in part by the base 3, are shown in outline at 4 and 5 respectively.

In part of the area of the housing of the appliance 1 beneath the plate 2 and surrounding the connector part 4, there is provided an electrical circuit shown as a block 6 which performs, as described in our patent No. GB-B 2228353, to give an audible warning when the liquid in the jug kettle 1 has boiled. Operation of the circuit 6 is dependent upon the condition of a normally open magnetically operable reed switch 7, however, and is inhibited unless the switch 7 is closed.

A permanent magnet 8 is disposed in the base 3, at a position where it can influence the switch 7 so as to close it when the rotational position of the appliance 1 relative to the base 3 is such as to bring the magnet 8 into sufficient proximity with the switch 7. This will occur only over a limited range of the 360 degree rotation relative to the base 3 of which the appliance is capable, and at other positions, the magnet 8 will not influence the switch 7 and the operation of circuit 6 will be inhibited. Thus the user can select, by the angle at which the appliance adopts relative to the base, whether to have the audible waming supplied by circuit 6 or not. The base of the appliance and/or the power base can be sectorally marked to indicate the range over which the circuit 6 will or will not operate, and such marking may be visual and/or tactile in nature. If desired, there may be provided co-operative mouldings on the appliance 1 and the base 2 designed and configured to cause the appliance to preferentially adopt a particular angular position relative to the base, but one from which it can be readily disturbed by rotation if desired.

In one example, the preferential position is that which locates the magnet 8 under the reed switch 7, so as to activate the circuit 6. However, appliance and base may alternatively be constructed to operate in the inverse situation, with the preferential position corresponding to the disabling of circuit 6.

It will be understood that one or more other magnets may be placed at different locations around the power base to provide plural sectors over which the circuit 6 is rendered operational. In this respect, the shaded ring 9 in Figure 2 shows the general area in which magnets such as 8 may be located to best effect in this embodiment. Further, circuits having different functions may be incorporated into the appliance 1 instead of or as well as the audible warning circuit 6.

It will also be evident that, if desired, the active circuitry such as 6 may be incorporated into the power base whilst the selector components, such as the magnet 8 would then be attached to or otherwise located in the appliance.

It will further be understood that the communication between the appliance 1 and the base 3 with regard to enabling and disabling the operation of circuits such as 6 may be effected by various means other than magnets and reed switches. Communication based upon optical, inductive or capacitive operation, for example, can be used instead if desired.

It will also be appreciated that the invention is not limited by any means to the use of an audible warning circuit such as 6. It may alternatively be used, for example, to switch between different power settings for an appliance and in particular to select a "keep warm" function and/or a fast heat-up function for certain kinds of appliance. With kettles in mind, the invention may be used to provide a convenient means of selectively operating an electric descaling device. In a further embodiment, the invention can be used to select a particular voltage supply range for the appliance. It can also be used to select a particular operating or cut-off temperature for the appliance.

The invention provides in general a new capability for appliance/base configurations capable of relative rotation over a sufficient angle to render sectoral selectivity of the kind described herein practical, and is not limited to any particular appliance or to any particular means of sectoral communication or control or to any particular functionality.

It is not essential that the base is a power base, although usually it will be, and, if a power base is used, it need not be of the kind described in the aforementioned international patent application.

Claims

1. A domestic electrical appliance including a base from which said appliance is removable, means permitting relative rotation between said appliance and said base, and means responsive to the rotational position of said appliance relative to said base to cause said appliance to operate or function differently at one such relative rotational position, or range of positions, as compared with the operation or function of said appliance at at least one other such relative rotational position or range of positions.

2. An appliance according to claim 1 wherein the relative rotation between said appliance and said base can extend through 360 degrees.

3. An appliance according to either of claims 1 or 2 wherein said base is connectable to an electrical supply and conveys electrical power to said appliance when the appliance is mounted thereon.

4. An appliance according to any preceding claim wherein one of said base and said appliance includes an actuator device and the other of said appliance and said base includes a responder means responsive to said actuator device; said actuator device and said responder means being disposed and arranged to cause said appliance to effect said different operation or function.

5. An appliance according to claim 4 wherein said actuator device comprises a magnetic device and said responder means includes switchable means sensitive to said magnetic device.

6. An appliance according to claim 4 or claim 5, wherein said actuator device is located in said base and said responder means is located in said appliance; the actuator means occupying a particular position on said base which is juxtaposed with said responder means only when the appliance and the base adopt a particular relative rotational disposition, or range of such dispositions.

7. An appliance according to any preceding claim wherein said different operation or function comprises the capability of providing an audible warning associated with the operation of said appliance.

8. An appliance according to any preceding claim wherein the arrangement is such that the same operation or function difference are caused to occur at each of a plurality of different relative rotational dispositions of said appliance and said base.

9. An appliance according to any preceding claim wherein the arrangement is such that a plurality of different operation or function differences are caused to occur at each of a plurality of different relative rotational dispositions of said appliance and said base.

10. An appliance according to any preceding claim comprising a kettle, wherein there is provided an electrical circuit arrangement for providing an audible indication that water in the appliance has boiled, and means for rendering the circuit arrangement effective or ineffective in dependence upon the rotational disposition of said kettle relative to said base.

11. An appliance according to any preceding claim wherein the base and the appliance carry visual markings to indicate relative rotational dispositions at which said appliance is caused to operate or function differently.

12. An appliance according to any preceding claim wherein the base and the appliance are formed with respective co-operative shapes to cause preferential adoption of a particular rotational disposition therebetween.

13. An appliance according to any preceding claim wherein the base and the appliance are configured to provide tactile indication of their relative rotational disposition.

14. An appliance according to any preceding claim and substantially as herein described.