GB2061091A

GB2061091A - An electrically heated cooking pot

Info

Publication number: GB2061091A
Application number: GB7936776A
Authority: GB
Original assignee: Pifco Ltd
Current assignee: Pifco Ltd
Priority date: 1979-10-23
Filing date: 1979-10-23
Publication date: 1981-05-13
Also published as: GB2061091B

Abstract

An electrically heated cooking pot of the slow cooker type comprises a dish (4) which is located within an outer casing (1) of the pot. The dish (4) is adapted to receive food to be cooked, preferably by means of a second removable dish (5), and has attached to the exterior side of its base an electrical element (6) for heating the food. A baffle plate (13) is located between the element (6) and the casing (1) which plate (13) covers the element (6) in order to reflect radiant heat from the element (6) towards the dish (4) and thereby protect the casing (1) from direct radiant heat. Variation of wattage produced by the element (6) may be achieved by using a central tapping or by selective connection in series to a resistance diode. <IMAGE>

Description

SPECIFICATION An electrically heated cooking pot The present invention relates to an electrically heated cooking pot of the type currently known as "slow cookers".

In conventional cooking pots of this type food can be slowly cooked over periods of several hours by the heating of the pot electrically using less than, for example two hundred Watts. Hence, these cooking pots are economical to use and suitable for use where it is possible and convenient to cook food over a long period of time.

According to the present invention there is provided a cooking pot adapted to be heated electrically and comprising a first dish which is located within an outer casing of the pot and which is adapted to receive food to be cooked, the base of the dish on its exterior side being attached to an electrical element for the heating of the dish and thereby the food and a baffle plate being located between the element and the casing to coverthe element and thereby reflect radiant heat from the element towards the dish to protect the casing from direct radiant heat.

Preferably, the casing is dish-shaped to contain said first dish which is attached at its rim to the casing, an air gap being provided between the side walls and the base of the dish and the casing.

Preferably also, the first dish is made of a good heat conducting material and is adapted to receive a removable second dish in which food can be placed for cooking.

The present invention will now be described by way of example with reference to the accompanying drawings in which: Fig. lisa cross-sectional view through a cooking pot according to the present invention; Fig. 2 is a view of the interior of a controls box for the cooking pot as shown in Fig. 1; Fig. 3 is a plan view of an electrical element for use in the cooking pot shown in Fig. 1 with a portion broken away to show the interior structure thereof; and Fig. 4 is a circuit diagram of a modified electrical circuitforthecooking pot shown in Fig. 1.

The cooking pot shown in Fig. 1 comprises a dishshaped outer casing 1 which is connected at its rim 2 to the rim 3 of a first dish 4. The first dish 4 is adapted to contain a removable casserole dish 5 within which food can be placed for cooking. The first dish 4 is heated by an electrical element 6 which is attached thereto and which is supplied with electrical current from a controls box 7 attached to the casing 1.

The casing 1 can be made of any suitable material but is preferably made of a heat resistant plastics material such as a high-temperature polypropylene.

As is described below, one of the advantages of the present invention is that radiant heat is nottransmit- ted directly from the element 6 to the casing 1 so that plastics materials can be used for the latter. The casing 1 is provided with a foot 8 at one side of its base and is attached to the controls box 7 at the other side via screws 9 so that the base 10 of the casing 1 does not rest directly on a supporting surface for the pot but is retained level when the pot rests on a horizontal surface. At the centre of the base 10 of the casing 1 is an inwardly recessed portion 11 which defines a circular aperture 12 through which the casing 1 is connected to a baffle plate 13 and thereby indirectly to the first dish 4.

The first dish 4 is preferably made of a good heat conducting material such as pressed aluminium. The rim 3 of the dish 4 is curved over outwardly of the dish and locates over the edge of the casing 1 into a rebated portion 14 of the rim 2 so that the dish 4 is positioned within the casing 1. The dish 4 is adapted to receive the casserole dish 5, which is of a slightly smaller size than the dish 4 so that the side wall 15 of the dish 5 does not contact the side wall of the dish 4 directly, and the base 16 of the dish 4 is provided with a pair of concentric circular ridges 17 to support the base 18 of the dish 5 to leave an air gap 19 between adjacent surfaces of the dishes 4 and 5.

Attached by bolts 20 to the exterior of the base 16 of the dish is the electrical element 6 so that heat can be transmitted directly to the dish 4 by radiation and conduction. The bolts 20 also locate the baffle plate 13 which is spaced from the element 6 to leave an air gap 21 but which completely covers the element 6.

The baffle plate 13 is preferably made so that its upper surface 22 is reflective to reflect back radiant heat emitted by the element towards the dish 4 and away from the casing 1. The lower surface 23 of the baffle plate 13 is preferably painted black. To prevent the dish 4 from being removed from the casing 1 by accident, the baffle plate 13 is provided at its centre with recessed portion 24 which is screwed to a clamping washer 25 that engages the exterior rim of the aperture 12 in the casing 1. The screw 26 that passes through the aperture 12 to attach the baffle plate 13 to the casing 1 passes through a sleeve 27 which acts as a spacer so that the screw 26 cannot be overtightened. In this way, the dish 4 is attached to the casing 1 so the element 6 cannot be accidently exposed.

As shown in Fig. 3, the element 6 comprises a clamping plate 28 via which the element 6 is attached to the dish 4 by means of the bolts 20.

Located between the plate 28 and the dish 4 is a wire wound element 29 with a central neutral tapping 30 and two end live tappings 31. The element 29 is wound so that when one end tapping 31 and the central neutral tapping 30 are used approximately 140 Watts can be generated when the cooking pot is connected to a mains electrical supply but when the other end tapping 31 and the central tapping 30 are employed only 75 Watts is generated. This permits the cooking pot to have a high and a low setting so that the cooking time can be varied.

The tappings 30 and 31 are connected in to the controls box 7 by leads which pass between the casing 1 and the dish 4 and into the box 7 via an aperture (not shown) in the casing 1. Within the controls box 7, as shown in Fig. 2 a mains lead 32 is clamped as at 33 and the live, neutral and earth wires 34,35, 36 respectively are connected into a 3-way terminal block 37. The earth wire 36 is connected via the block 37 to a wire 38 which is attached to one of the bolts 20 by a ring terminal 39 so that the dish 4, baffle plate 13 and washer 25 are all earthed.The live and neutral wires 34 and 35 are connected into a circuit comprising a neon light arrangement 40 so that a user can be warned when the mains supply is con nected to the cooking pot and to a switch arrangement 41 whereby the user can select a high our a low voltage via the end and centre tappings 30 and 31.

In a modification as shown diagrammatically in Fig. 4, the whole of the element 29 may always be utilised and the central tapping 30 dispensed with. In this case, a diode 42 is connected into the circuit attached to the block 37 and the switch arrangement 41 arranged such that if the diode 42 is connected into the circuit the wattage of the element 29 is reduced by approximately one half.

In use, the casserole dish 5 is filled with food to be cooked and placed within the dish 4. The user then connects the cooking pot to a mains electricity supply and selects eitherthe high or the low setting to cook the food faster or slower as desired. The casserole dish 5, which is preferably made of a heat resistant glass, is heated via the dish 4 which, in turn, is heated by the element 6. The air gap between the dish 4 and the casing 1 prevents heat from being conducted to the casing 1 so that the latter is not heated and always remains capable of being handled. The casing 1 is also protected from radiant heat by the baffle plate 13 which reflects radiation back towards the dish 4 and also acts as a heat sink so that heat can be stored and not wasted. Thus the use of the baffle plate 13 and the aforesaid air gap enables the cooking pot to be constructed without the need for a solid insulating material to be packed between the dish 4 and the casing 1 and enables the casing 1 to be made of plastics material as described.

Claims

1. A cooking pot adapted to be heated electrically and comprising a first dish which is located within an outer casing ofthe pot and which is adapted to receive food to be cooked, the base of the dish on its exterior side being attached to an electrical element for the heating of the dish and thereby the food and a baffle plate being located between the element and the casing to cover the element and thereby reflect radiant heat from the element towards the dish to protect the casing from direct radiant heat.

2. A cooking pot as claimed in claim 1, in which the casing is dish-shaped to contain said first dish which is attached at its rim to the casing, an air gap being provided between the side walls and the base of the dish and the casing.

3. A cooking pot as claimed in claim 2, in which the casing is made substantially of a plastics material.

4. A cooking pot as claimed in any one of claims 1 to 3, in which the first dish is made of a good heat conducting material and is adapted to receive a removable second dish in which food can be placed for cooking.

5. A cooking pot as claimed in any one of claims 1 to 4, in which the baffle plate is connected to the first dish and to the outer casing.

6. A cooking pot as claimed in claim 5, in which the baffle plate is attached to the first dish by the same means as the electrical element, an air gap being provided between the baffle plate and the electrical element

7. A cooking pot as claimed in any one of claims 1 to 6, in which the electrical element is a wire wound element with two end tappings and a central tapping so that a first wattage can be generated to heat the first dish when one end tapping and the central tapping are employed and a second wattage different from the first wattage can be generated when the other end tapping and the central tapping are employed.

8. A cooking pot as claimed in any one of claims 1 to 6, in which the electrical element is connectable in series with an electrical resistance whereby when the element alone is connected to an electricity supply a first wattage can be generated to heat the first dish and when the element and the resistance connected in series are connected to an electricity supply a second wattage different from the first wattage can be generated to heat the first dish.

9. A cooking pot as claimed in claim 8, in which the electrical resistance comprises a diode.

10. A cooking pot adapted to be heated electrical substantially as hereinbefore described with referpence to Figs. 1 and 2 and Fig. 3 or 4 of the accompanying drawings.