GB2128876A - Cooking-devices - Google Patents

Abstract

A top-of-stove oven comprises a hollow container 10 which is placed on a gas ring 20 and the base of the container has a number of openings 18 through which the hot gases from the burner pass in an upward and radially outward direction into the container, the openings terminating near the outer periphery of the container. The container has a lid 14 and a heat spacer plate 30 is positioned above the openings and spaced from the base of the container. A pan 34 or the like containing food to be cooked can rest on the heat spacer plate which does not get too hot and so burn the food since it is not in direct contact with the base of the container or in the direct flowpath of the hot gases. The plate 30 is of aluminium, and has dimples 32 and a reflective lower surface 31. <IMAGE>

Description

SPECIFICATION Improvements in cooking devices This invention relates to cooking devices and in particulartop-of-stove ovens.

Conventional ovens are relatively large and occupy a lot of space. Also they consume a lot of energy to heat up the relatively large volume ofthe oven. They are reasonably efficient in cooking food when the oven is full but are very inefficient and wasteful of energy if only one or two items of food are being cooked. Also ovens are not easy to clean after use.

It is therefore an object of this invention to provide a cooking device which will simulate cooking in an oven but which can be smaller and so more energy efficient than an oven.

According to the invention there is provided a cooking device comprising a hollow container in which items are placed for cooking and which is intended to be heated from beneath by being placed on, for example, a gas ring, the container having a base in which are provided a number of openings terminating nearthe outer periphery ofthe container and through which the hot gases pass into the container, a removable lid which fits over the base, and a heat spacer plate positioned above the openings and spaced upwardlyfrom the base which is in direct contact with the gas flame whereby a pan orthe like containing food to be cooked can rest on the heat spacer plate and hot gases can pass upwardly th rough the openings around the edge of the spacer plate and upwardly into the restofthecontainerto cookfood in a pan resting on the heat spacer plate.

Such a device can be very efficient for use in cooking food since it can be smallerthan an oven and also has the advantagethat because it uses as its heat source a conventional gas ring or burner, it can be used entirely in place of an oven if space is at a premium.

Alternatively, it can be used on a gas burner on the top of a cooking stoveattimeswhen only a relatively small amount of food is to be cooked.

We also find that the food which is cooked in this device is cooked in a manner simulating normal roasting in an oven. Thus, well browned meat can be achieved without burning of the base of the meat.

According to one prior proposal for a top-of-stove oven, a device having a central upward funnel-like passage is provided for the hot gases and the food is arranged in an annular portion surrounding the central funnel. Whilst such a proposal has managed to achieve cooking of the top surface offood contained in the annular portion, it has also resulted in burning of that portion ofthefood resting on the base ofthe device in direct contact with the base which it is directly heated by the gas flame. In the device of the invention, the spacer plate helps to avoid direct contact of the food with very hot surfaces and the shape ofthe cooking area is not limited by a central opening.

To avoid an excessive build-up of steam in the hollow container, one or more small air vents are preferably provided through the top of the lid.

Also, to allowthe user to watch the progress of the cooking, it is desirable forthe lid to have a glass or other transparent portion or if not, to made wholly of transparent material.

The heat spacer sheet prevents direct contact between the roasting pan and the very hot base of the device so preventing burning of the lower surface of the food being cooked and also drying up of anyjuices and resulting carbonisation or burning of them.

Additionally, this sheet desirably has a reasonably reflective undersurface so that it also acts to reflect downwardly away from the roasting pan direct radiant heatfrom the gas flame and the base ofthe device.

The presence ofthe openings in the base seems to promote heat and air cirulation within the container and as a resultthe general airtemperature seemsto be increased in the centre aroundthefood. Also this circulation reduces the temperature gradient existing through the height of the container since the objective is not to cookthefood by heat applied beneath the foodbuttocookthefood by heat from the hot air around the food. The optimum number, size and shape of these openings for a particular size of device can be found by experiment. The openings should however conduct the hot gases in an upward and radially outward direction.

The openings in the base of the device can be in the form of a number of radially arranged flutings. In this way, the hot gases which enter the device are conducted upwardly and outwardly towards the edge or periphery of the container and do not directly impinge on the underneath ofthe heat spacer sheet.

The invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a half-plan view of the body of a cooking device according to the invention; Figure 2 is an upright section taken on line 2-2 of Figure 1; Figure 3 is a section taken on line 3-3 of Figure 1; and Figure 4 is a section taken on line 4-4 of Figure 1.

A cooking device 10 shown in the drawings comprises a bowl-shaped body 12 provided with a removable lid 14.

The base 15 is slightly domed and four radial upwardly raised ribs 16 are provided. These ribs stiffen the base 15 and are of an inverted "U" section as best shown in Figure 2.

Towards the outside of the base 15 are eightfluted openings 18. These have been formed by severing the material of the base along the lines 19 and pressing outthese openings so that the openings 18 have open ends 18a.The openings 18 are equally angularly spaced at 45" to one another and are of fluted shape, having a prógressively increasing width in the radial direction and, as best shown in Figure 2 are inclined upwardly in a radially outward direction. Thus, hot gasesfromthe gasflames 20 are guided in an upward and outward direction into the hollow interior 21 ofthe cooking device 10.

Thenumberandsizeoftheopenings l8canbe determined by suitable experimentation. We have found however that a convenient number is eight with the axes of adjacent pairs being angled at about 45" to one another and the sum of the radial angles ofthe opening being approximately 1800. There could be more or less openings, e.g. 6to 10 openings but it appearsthatthe sum of their radial angles ofopening should be around 1800 and preferablyfrom 100to 260".

It is also desirable, but not essential that the openings be relatively short in the radial direction, e.g.

have a radial length approximately 25% of a radius, and moregenerallyfrom 20to 30% of a radius. This ensures that they are themselves relatively rigid in construction and thatthe base 15 is kept rigid. The tops of the fluted openings can therefore be used to supportthe weight of food to be cooked as will be described in due course. It is also important thatthe open ends 18aoftheopenings 18terminate nearthe outside of the container, e.g. within 20 to 30%, and preferably about 25% of a radial length from the outer periphery of the pan.

Itwill be noted that the ribs 16 merge into four ofthe eight openings 18. These ribs help to stiffen the base 15 and also assist in conducting some hot gases from the centre of the base to some of the openings.

Spaced upwardly from the base of the body 12 is a heat spacer and/or reflector sheet 30. This is a sheet of metal which can rest freely on the tops of the fluted openings 18.

The sheet 30 preferably has an underside 31 which is reasonably heat reflective and its spacing from the base of the body which isincontactwiththegasflame optionally together with this reflective surface ensures that the spacer plate 30 does not become overheated.

Also, it will be noted that the shape of the openings 18which conductthe hot gases in an upward and outward direction ensuresthatthevery hot gases from the flames 20 do not impinge directly on the underside of the heat spacer sheet 30 other than at its outer edges.

The heat spacer sheet 30 is desirably not perforated by any holes and is provided with a number of upwardly raised dimples 32 and a roasting pan 34 in which food is cooked rests on these so that it is not in intimate heat contact with the sheet 30. The roasting pan is preferably not permanently connected to the sheet 30 so that it can be removed easily from the device 10. The roasting pan 34 can be of any convenient material such as metal or heat-resistant glass.

Inthetop ofthe lid are provided one or more small airvents 36, e.g. having a radial extent of opening of 30", to prevent the accumulation of steam and the like and to help promote circulation of the hot airwithin the device 10. The lid is provided with a knob 38 to allowthe ready removal of the lid and, to enablethe userto watch the progress of the cooking, a central transparent glass disc40 is provided.

The lid, body 12 and spacer plate 30 are preferably made of metal such as aluminium which can readily be cleaned.

In use, the food to be cooked in the roasting pan is placed within the device 10 Which is in turn placed over a gas burner. The hot gases from the burner pass upwardly into the hollow device 1 0through the openings 18 and the hot gases are deflected by the openings so thatthey pass upwardly around the periphery ofthe device 10 and circulate in the direction ofthe arrows 50. Because they do not impinge directly on the heat spacer and reflector sheet 30, the area of the roasting pan 34 does not become overheated and so good roasting is achieved by the presence of the very hot gases within the device 10.

Claims (8)

1. A cooking device comprising a hollow container in which items are placed for cooking and which is intended to be heated from beneath by being placed on,forexample,a gas ring, the container having a base in which are provided a number of openings terminating nearthe outer periphery of the container and through which the hot gases pass, a removable lid which fits overthe base, and a heat spacer plate positioned above the openings and spaced upwardly from the base which is in direct contact with the gas flame whereby a pan orthe like containing food to be cooked can rest on the heat spacer plate and hot gases can pass upwardly through the openings around the edge of the spacer plate and upwardly into the rest of the container to cook food in a pan resting on the heat spacer plate.

2. A cooking device as claimed in Claim 1 in which one or more small air vents are provided through the lid.

3. A cooking device as claimed in Claim 1 or Claim 2 in which at least part ofthe lid is transparent.

4. A cooking device as claimed in any preceding claim inwhichtheundersideoftheheatspacerplate has a heat reflective surface.

5. Acooking device as claimed in any preceding claim in which the total ofthe radial extent of the openings is from 100 to 2600.

6. Acooking device as claimed in any preceding claim in which there are from 6to 10 angularly spaced openings.

7. Acooking device as claimed in Claim 5 which there are eight openings, each approximately 45" in radial extent.

8. A cooking device substantially as herein described with reference to the accompanying drawings.