GB2141920A - Automatic kettles - Google Patents

Abstract

A kettle having a handle (11) moulded from a steam resistant material, e.g. a thermoplastics material, so as to define, in a first end portion (40), a steam duct (46) which extends through the first end portion (40) to direct steam from a steam vent (44) towards a mechanism (13). The steam vent is disposed in a body wall (15) of the kettle at a position which is higher than the position at which an aperture is provided in said body wall to receive a fastener (41) securing said first end portion to said body wall. <IMAGE>

Description

SPECIFICATION Automatic kettles This invention concerns electric kettles, of the kind known as automatic kettles, which incorporate a mechanism responsive to being subjected to steam to actuate an electrical switch to switch off a power supply to a heater of the kettle.

In some automatic kettles, a steam tube extends downwards within a body of the kettle from above the maximum water level to an immersion heater assembly, and through part of the latter assembly to the mechanism. However the use of a steam tube has well known disadvantages.

In other automatic kettles, the need for a steam tube is avoided by providing a steam vent or opening in an upper part of a side wall of the body of the kettle, to allow steam to escape from the body, and by positioning the mechanism, or part of the mechanism, close to the steam vent or opening so that escaping steam impinges on the mechanism.

The use of a steam vent or opening incurs several disadvantages such as the need to leave a large headspace above maximum water level within the kettle: the need to employ a handle having a metal endpiece or a plurality of fasteners for securing an end of the handle to a part of the wall above the level of or spaced apart from the steam vent or opening; the other constraints imposed by the position of the steam vent or aperture upon the designing and manufacturing of the kettles.

An object of the invention is to provide an improved automatic kettle which can be constructed so as to reduce these disadvantages.

According to the present invention there is.

provided an automatic kettle comprising a vessel having a body wall; a handle having spaced apart end portions secured by fasteners to the body wall; a mechanism responsive to being subjected to steam to actuate an electrical switch electrically connected to a heater of the kettle; and a steam vent in said body wall to allow steam to flow from within the vessel to said mechanism, and characterised in that:: (a) the handle is moulded from a steam resistant material, e.g. a thermoplastics material, so as to define, in a first one of said end portions, a steam duct which extends through the first end portion to direct steam from said steam vent towards said mechanism, and (b) the steam vent is disposed in said body wall at a position which is higher than the portion at which an aperture is provided in said body wall to receive one of said fasteners securing said first end portion to said body wall.

The steam duct is preferably constituted by one part of an opening moulded into said first end portion, and said opening preferably comprises a further part which is shaped to receive said one of the fasteners.

The invention will be described further, by way of example, with reference to the accompanying diagrammatic drawing, which shows part of a kettle of the invention in vertical cross-section.

The kettle comprises a vessel 10, a handle 11, an immersion heater assembly 12, a mechanism 13, and a cover 14.

The vessel 10 has a metal wall 15 integral with a bottom 16. The immersion heater assembly 12 is of known form and comprises an element 20 which is secured to a metal head 21 which extends through a lower aperture in the wall 1 5.

The head 21 has a flange 22 and an internally threaded ring 23 engages an externally threaded cylindrical part of the head 21 so as to cause a sealing ring 24 and a portion of the wall 15 around the aperature to be clamped between the flange 22 and the ring 23. The immersion heater assembly 12 is provided with a switch assembly 25 incorporating a switch (not shown) actuable by means of a push rod 26. The switch assembly is secured to the head 21 and provides a socket extension 27 to receive an electrical supply connector (not shown). The switch is electrically connected in series between the element and at least one electrical input terminal of the switch assembly.

The mechanism 13 comprises a lever 30 mounted on a pivot 31 carried by a support 32; and a heat responsive member, such as a bimetal 33, carried by an upper part 34 of the support 32.

The part 34 is engaged by a spring 35 which provides an over-centre bias for the lever 30.

The handle 11 is moulded from a thermoplastics material which is resistant to degradation by steam. A front end portion (not shown) of the handle is secured to the wall 15 adjacent to a spout (not shown) of the vessel; and a rear end portion 40 of the handle is secured to the wall 15 above the heater assembly 12 by means of a fastener 41 which extends through a hole 42 in said wall and through a shaped part of an opening 43 moulded into the portion 40.

The wall 15 is provided with a steam vent 44 disposed above the level of the hole 42 and between the hole 42 and a lid opening 45.

The lid opening 45 is disposed centrally at the top of the vessel. The opening 43 has a further portion which overlies the vent 44 and extends through the rear end portion 40 of the handle 11 to serve as a steam duct 46 which, in use, directs some of the steam issuing from the steam vent 44 generally towards the upper part 34 and the metal 33 for actuation of the mechanism 13. In relation to a vertical centre line 47 of the vessel 1 0, the distance of the vent 44 from the centre line 47 is considerably less than the distances of the hole 42 and said shaped part of the opening 43 from the centre line, so that the vent 44 can be disposed higher up the wall 15 than the hole 42 and the lowermost part of the rear end portion 40.

This arrangement of the steam vent 44 and the provision of the steam duct 46 to direct steam rearwards above and past the top of the fastener 41 , enables the vessel to be filled with water to a very high level to minimise the headspace between maximum water level (indicated by line 48) and the top of the wall 15, so that, for a given water capacity, the size and cost of the vessel can be reduced considerably.

Furthermore, said arrangement of the steam vent and the steam duct removes some of the aforementioned constraints imposed upon the design of the kettle. For example, said end portions of the handle may be made similar in shape and configuration in a manner employed for handles for some non-automatic, whereby to enable one set of moulding tools to be use for making handles for non-automatic and automatic kettles provided that a removable tool insert is provided to mould the steam ducts. Also, because the steam vent is closer to the centre line, the portion of the wall around the lower aperture may be displaced inwards to move the switch assembly and the mechanism towards the vessel thereby enabling a smaller cover having a reduced rearwards projection to be employed; and the span of the handle relative to the diameter of the vessel may be increased to enable a larger lid to be employed, as indicated partially in broken lines, to give further cost savings.

Claims (5)

1. An automatic kettle comprising a vessel having a body wall; a handle having spaced apart end portions secured by fasteners to the body wall; a mechanism responsive to being subjected to steam to actuate an electrical switch electrically connected to a heater of the kettle; and a steam vent in said body wall to allow steam to flow from within the vessel to said mechanism, and characterised in that:: (a) the handle is moulded from a steam resistant material, e.g. a thermoplastics material, so as to define, in a first one of said end portions, a steam duct which extends through the first end portion to direct steam from said steam vent towards said mechanism, and (b) the steam vent is disposed in said body wall at a position which is higher than the position at which an aperture is provided in said body wall to receive one of said fasteners securing said first end portion to said body wall.

2. An automatic kettle as claimed in Claim 1, wherein the steam duct is constituted by one part of an opening moulded into said first end portion.

3. An automatic kettle as claimed in Claim 2, wherein said opening comprises a further part which is shaped to receive said one of the fasteners.

4. An automatic kettle as claimed in Claim 1,2 or 3, wherein the mechanism is separate from said handle.

5. An automatic kettle substantially as hereinbefore described with reference to the accompanying drawing.