GB2140672A - Griddle unit - Google Patents

Abstract

A griddle unit comprises a base unit (10) which houses an electrical heating element (12) and a removable tray unit (14) supported on the base unit over the heating element, with an air space between the tray unit and heating element. The heating element (12) is of low wattage and is energised from the mains supply, without internal variable voltage or current control, so as to operate at all times using "black" heat. Air gaps (74) are provided between the removable tray (14) and the base unit (10) to provide a path for the escape of hot air from the interior of the base unit. <IMAGE>

Description

SPECIFICATION Griddle unit The present invention relates to griddle units.

A griddle unit for use on a domestic cooker is known from our U.K. Patent No. 14488878, which comprises a metal tray of generally rectangular form having an upper surface for receiving food for cooking and having formations thereon upon which such food is supported in use so as to permit drainage of fats and juices therefrom, and heat-resistant non-metallic stand portions attached to opposite ends of the tray and arranged to support the tray on a surface of the cooker so that the underside of the tray is spaced a predetermined distance above a heating element of the cooker.

This known unit has, of course, the disadvantage that it does not include its own primary heat source so that it must be used in association with another piece of equipment which provides the necessary heat, such as a conventional cooker.

It is therefore one object of the present invention to provide a griddle unit having the advantages of the unit of U.K Patent No. 1488878 with the additional facility of being self-contained with regard to its heat source.

It is another object of the present invention to provide a self-contained griddle unit which operates with only a simple on/off switch and achieves the correct temperature for cooking without the necessity for complicated and expensive electrical controls.

In accordance with the present invention, there is provided a griddle unit comprising a base unit which contains an electrical heating element and a removable tray unit adapted to be supported on the base unit over the heating element, with an air space between the tray unit an heating element, the heating element being arranged to be energised from the main's supply, without iriternal variable voltage or current control, so as to operate at all times using "black" heat.

In this manner, it can be arranged that the temperature of the cooking surface of the tray does not rise substantially above a predetermined temperature, preferably 1 900 C, the latter temperature being well below the smoking and flash points of virtually all proprietary cooking oils and fats.

Advantageously, the construction of the base unit is such as to establish a continuous air flow over at least some of the side walls of the base unit, the latter air flow serving to assist in maintaining a substantially constant operating temperature for the griddle unit.

It is also advantageous for air gaps to be provided between the removable tray and the base unit to provide a path for the escape of hot air from the interior of the base unit.

The invention is described further hereinafter, by way of example only, with reference to the accompanying drawings, in which: Fig. 1 is a perspective view of one embodiment of a griddle unit in accordance with the present invention; Fig. 2 is a perspective view corresponding to Fig. 1 but with a metal tray part of the unit removed to expose the electrical heating element; and Fig. 3 is a transverse section on line Ill-Ill of Fig. 1.

The illustrated griddle unit comprises essentially a base unit 10 (Fig. 2) containing an electrical heating element 12 over which a removable tray unit 14 is adapted to be supported in a manner described in detail below.

The base unit 10 comprises a shallow dishshaped member 16 formed from sheet metal and having a horizontal base 18, side walls 20, 22 and end walls 24. The base wall is arranged to be spaced from a surface on which the unit 10 is standing by means of a pair of transverse spacer beams 26, made of wood or a plastics material, having feet 28. The underside of the base wall 1 8 carries a junction box 30 for receiving an electrical mains cable 32. Side wall 22 carries an indicator lamp 34 to show when the unit is activated.

Above the member 16, there is disposed a channel-shaped member 36 which is also pressed from metal sheet and which has a horizontal base 38 and upstanding side walls 40, 42. The base 38 carries a plate 44 of electrically insulating material to which the outer metal sheath of the electrical heating element 10 is rigidly attached. The two ends of the heating element extend through the plate 44 and terminate at two solder tags 48, 50 disposed therebeneath. Electrical lead wires connect the tags 48, 50, and hence the heating element, to the junction box 30 (via an on/off switch - not shown) also they are coupled directly to the mains lead 32.One or more upstanding members 52 (Fig. 2) can be provided on the base 38 for supporting the heating element 10 in a fixed horizontal attitude.

Disposed longitudinally of the unit, alongside but slightly spaced by respective air gaps 53 from the outer surfaces of the side walls 40, 42, are a pair of hollow side panels 54, 56, which again can be formed from pressed metal sheeting. When the side walls 40, 42 heat up in use, an air flow is set up over these walls by virtue of the existance of the latter air gaps 53 and this assists in keeping the walls 40, 42 relatively cool. At the same time, the panels 54, 56 themselves remain cool and can therefore be used, if required, for assisting the lifting or manoeuvring of the unit. This removal of heat from the side wall region of the base unit also assists in preventing overali overheating of the griddle unit.

The top edges of the upstanding, longitudinally extending side walls 40, 42 of the channel-shaped member 36 provide supports for engaging under the longitudinal side edges of the removable tray unit 14, as best seen in Fig. 3. The tray unit 14 is formed as a pressing from metal sheet and has a plurality of ribs 60 across its width adjacent one end and a planar surface portion 62 adjacent the other end. The ribs 60 are designed to support certain types of food when being cooked so as to permit drainage of fats and juices therefrom. The planar surface portion 62 may be formed with one or more shallow, part spherical recesses 64 for use in frying eggs or the like.

As can be seen from Fig. 3, the removable tray unit 14 is formed along one or both longitudinal marginal edges with gutters 66 into which cooking oil or fat can drain in use and be used for basting.

The tray unit is preferably completely covered on all sides in a non-stick material, such as Teflon.

The tray unit 14 has a depending peripheral skirt portion 68 which, when the tray unit is applied to the base, unit, sits over and around the upstanding side walls 40,42, as best seen in Fig.

3. The longitudinal ends of the tray unit 14 carry respective plastic end pieces 70, 72 which serve firstly to enable the tray unit to be lifted off the base unit by hand and secondly to provide a small air space 74 at each end of the tray unit for the entry and exit of air to the interior chamber containing the heating element. For this purpose, the bottom surfaces of the plastics end pieces 70, 72 have downwardly extending projections 76, 78 which engage in respective recesses 79 in the upper surface of further plastics end pieces 80, 82 attached to the two longitudinal ends of the base unit 10. The latter plastics end pieces 80, 82 provide the parts by which the base portion can be picked up by hand when the unit is activated or deactivated but still hot.

In use, the heating element is energised by connection to the mains supply via on/off switch (not shown). It is advantageous to use a heating element of less than 1 Kw rating, 850w being the prefered maximum value in order to save energy and to enable the element to work on "black" heat (i.e. it does not glow red hot) which greatly increases element life and minimizes service problems. By limiting the loading to 850 watts, it also enables the unit to be safely used on an extension lead for barbecues and patio cooking.

The underside of the tray unit is heated by radiation and convection from the heating element and it is found that, by limiting the power rating of the element as described above, near perfect surface temperatures are obtained for griddling all suitable types of food, without the necessity for variable control of the element temperature. At the same time, it has been found to be virtually impossible to obtain overheating of the tray, thereby substantially eliminating smoking of cooking fats and oils. The establishment and maintenance of such advantageous cooking temperatures is assisted by the abovedescribed provision of the air flow over the side walls 40,42 established by the air gaps between these walls and the side panels 54, 56 and the provision of the air gaps 74 at the longitudinal ends of the tray.

Home Office research has shown that proprietary vegetable cooking oils, lard and hydrogenated cooking fats usually have smoke points above 2100C and flash points above 2400C. Results of tests with the present griddle unit have shown that within six minutes of switchon the cooking surface reaches 149 , this being suitable for dry frying for which the griddle is primarily intended. After about eight minutes the surface temperature is ideal for cooking eggs, etc.

and after 15 minutes toasting temperature is reached. Thereafter, the surface temperature remains substantially constant at about 1900 and there is no further appreciable rise of temperature with time.

When cooling is finished, it will be appreciated that cleaning of the tray unit is extremely easy as it can be simply lifted off an immersed entirely for cleaning without any risk of damage whatsoever.

A major advantage is thus that the griddle cannot be abused and will not attain temperatures significantly in excess of 1900 C. As this is well below the curing temperature of the non-stick covering (3700C) there will be none of the problems sometimes experienced in this type of appliance (infra-red cookers etc.) due to overheating. If non-stick is constantly subjected to high temperatures at about 3000C upwards then this can cause a softening of the material. This can lead to fat impregnation and a possibility of peeling, or the non-stick becoming tacky. None of these problems are likely with the present appliance.

As discussed above, the surface temperature of the griddle remains well below the flash point and ignition temperatures of all standard oils and cooking fats, even when the appliance is abused and left on for considerable periods of time. The appliance also proves to be relatively smoke free, operating as it does at a temperature below that of the smoke point for most fats. It is, therefore, relatively clean to use in comparison with known appliances.

As it operates on a simple on/off switch, the use of complicated and expensive controls is avoided.

The pressed metal parts can be made from a convenient low weight material, such as aluminium or an aluminium alloy.

Claims (9)

1. A griddle unit comprising a base unit which contains an electrical heating element and a removable tray unit adapted to be supported on the base unit over the heating element, with an air space between the tray unit and heating element, the heating element being arranged to be energised from the mains supply, without internal variable voltage or current control, so as to operate at all times using "black" heat.

2. A griddle unit as claimed in claim 1, wherein the base unit comprises a channel-shaped, pressed-metal member having upstanding side and end walls and containing the heating element.

3. A griddle unit as claimed in claim 2, wherein a respective side panel is disposed alongside but spaced by an air gap from both said upstanding side walls, whereby to promote, in use, a continuous air flow over these side walls via said air gaps.

4. A griddle unit as claimed in claim 3, wherein the side panels are hollow and are formed form pressed-metal sheet.

5. A griddle unit as claimed in claim 1, 2, 3 or 4, including one or more air gaps between the removable tray and the base unit to provide a path for the escape of hot air from the interior of the base unit.

6. A griddle unit as claimed in claim 2,3 or 4, wherein the tray unit has a depending peripheral skirt and is supported on the base unit so that there is an air gap between the upper edges of the upstanding end walls of the channel-shaped member and respective end portions of said depending peripheral skirt.

7. A griddle unit as claimed in claim 6, wherein the longitudinal ends of the tray unit are formed by respective plastics end pieces having downwardly extending projections which engage in respective recesses in the base unit whereby to support the tray unit above the base unit with said air gaps between the upstanding end walls of the channelshaped member and said end portions of the depending peripheral skirt.

8. A griddle unit comprising a base unit which contains an electrical heating element, and a removable tray unit adapted to be supported on the base unit over the heating element with an air space between the tray unit and the heating element, said air space communicating permanently with the atmosphere via air gaps disposed between the tray unit and base unit at opposite-ends of-the griddle unit, the heating element being arranged to be energised from the mains supply, without internal variable voltage or current control, so as to operate at all times using "black" heat.

9. A griddle unit substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.