GB1601690A - Fan assisted grill oven - Google Patents

Description

(54) FAN ASSISTED GRILL OVEN (71) We, BELLING & COMPANY LIMITED, a British Company of Bridge Works, Southbury Road, Enfield, Middlesex, do hereby declare the invention, for which We pray that a patent may be granted to us, and the method by which it is to be perfermed, to be particularly described in and by the following statement: This invention relates to an oven.

More particularly the invention provides an oven which may be used for grilling baking or roasting food by circulated hot air, which comprises an oven chamber defined by a roof, side walls ,a floor, a rear wall and a hinged door, an electrical heating element positioned within the oven immediately below the roof in spaced parallel relationship thereto, an impeller for circulating air within the oven and in fluid communication therewith via an outlet duot opening to the oven close to its roof and an inlet duct also opening to the oven close to its roof but below the outlet duct, a tray which slideably engages support means within the oven so that it may be inserted at a selected one of a plurality of vertical levels between the level at which the inlet duct opens to the oven and the level defined by the floor of the oven with the periphery of the tray closely spaced from the adjoining portions of the oven chamber to define an upper space which during grilling baking or roasting by circulated hot air is heated by the circulating air and a lower space which is substantially unheated thereby, and a baffle plate which fits within the oven below the heating element to conceal the heating element and define with the roof of the oven a flow passage along which air from the outlet duct is directed in heat-transferring contact with the heating element, the baffle plate being formed with spaced perforations and deflector ribs for deflecting some of the air downwardly into the space above the tray at intermediate positions along the flow passage.

An embodiment of the invention will now be described by way of example only with reference to the accompanying drawings in which: Figure 1 is a diagrammatic front sectional view of a grill oven; and Figure 2 is a diagrammatic side sectional view of the grill oven shown in Figure 1.

In the drawings a grill oven chamber is defined by side walls 1 and 2, a roof 3, a floor 4, a rear wall 5 and a hinged door 6. The roof, floor and side walls are formed with outwardly directed flanges 7 against which the door 6 closes, an intermediate sealing gasket maintaining an air-tight seal between the door and the side walls when the door is closed. The side walls 1 and 2 are swaged to form support ribs 9 extending into the oven chamber and engaging horizontally directed side flanges 11 of a removeable food pan or tray 10 for supporting the food tray at one of a number of possible levels within the chamber. Food to be cooked can rest on a wire grill 12 which stands on the floor of the food tray 10.

The roof, floor, rear wall and side walls of the oven chamber may be positioned within a thermally insulated sheet metal housing.

A serpentine electrical heating element 13 is fastened within the oven chamber in spaced parallel relationship to the roof 3 and extends across substantially the whole of the width of the roof and across a major portion of the depth of the roof.

An impeller 14 within the oven chamber is positioned centrally of the rear wall 5 and closely spaced therefrom. It is driven via a drive shaft 15 extending through the rear wall 5 by means of an electric motor 16 mounted thereon externally of the oven chamber. An inner deflector plate 17 mounted within the oven chamber on the rear wall 5 in spaced parallel relation ship thereto defines with the rear wall an impeller space which has an air inlet constituted by an aperture 18 in the face of the plate If positiòned in front of the hub 19 of the impeller and an air outlet 20 directed towards the roof 3 and constituted by an upper portion of the plate 17.

An outer deflector plate 21 mounted on the inner deflector plate 17 in spaced parallel relationship thereto defines with the upper end of the plate 17 an air inlet channel opening to an upper portion of the oven adjacent its rear wall and leading to the air inlet aperture 18. Thus there are formed an air outlet duct opening to the oven chamber close to the roof 3 and an air inlet duct also opening to the oven chamber close to the roof 3 but below the outlet duct. A scroll 22 (Figure 1) fixed within the impeller cavity directs the flow of air from the impeller so that it impinges on the roof 3 of the oven at a pcsi- tion such that the air circulates approximately uniformly over the width of the oven.

The inner edge of the food tray 10 is formed with a flange 23 for abutment with the outer deflector plate 21. The outer edge of the food tray 10 is formed with an offset 24 which abuts against or is closely spaced from the door 6. As a result the roof 3, base of the tray 10, door 6 and plate 21 together define a cooking space in which a circulation of air can be produced by the impeller 14, relatively little of the circulated air passing into the pace within the oven chamber beneath the tray 10. In effect the tray 10 acts as the floor of the oven. Depending upon the nature of the food being cooked, the tray 10 can be inserted at an upper portion of the oven chamber as shown in Figure 2 for grilling and it can also be inserted in one of a number of lower positions as shown in Figure 1, most usually for baking or roasting.

A removable baffle plate 25 is inserted into the oven chamber below the heating element 13 and parallel to the roof 3 during grilling baking or roasting food by circulated air. The baffle plate conceals thc heating element 13 and defines a flow channel along which air from the outlet 20 is directed over the heating element 13 and it has spaced perforations and deflector ribs 26 for deflecting some of the air passing along the flow channel in the direction of the door through the said perfora- tions into the space above the tray 10. The baffle plate may be removed for grilling by radiant heat.

A bead 27 of arcuate cross-section is positioned along the top outer edge of the oven chamber adjacent the door. It deflects the flow of air along the top of the oven downwardly, assists in establishing a circulation of air through the oven and elminates excessive turbulence at this point.

In circulated air grilling, baking or roasting the tray 10 is inserted into the oven at the appropriate level, the heating element 13 is energised and the motor 16 is switched on. The impeller produces a recirculating current of air through the cooling space, the air circulating in a clockwise direction as seen in Figure 2.

The oven door 6 may be kept closed during grilling as well as during baking. The current of air from the impeller 14 is directed along the roof 3 and travels transversely of the heating element 13. Hot air is then deflected by the bead 27 and by the ribs 26 of the baffle 25 into the space above the tray 10 where it circulates around food supported on the grid 12. Air is withdrawn from the cooking space via the passage between the plates 21 and 17 and is returned to the impeller 14 for recirculation.

The grill oven described above has the advantage that it is versatile, being capable of operating as a grill and as a conventional baking and roasting oven. It requires a single heating element whereas previous designs of grill oven required separate heating elements to perform the functions of a grill and of an oven. The fact that the food pan or tray acts as the floor of the oven means that only the cooking space is heated and as can he seen from Figure 2 when only a small quantity of food is to be cooked, the cooking space is relatively small compared with the overall volume of the grill oven. Consequently the oven heats up rapidly and is economical in its consumption of electricity.

It is an advantage of the oven described herein that the volume of the cooking space is flexible and may be varied by the user in accordance with the amount and type of food to be cooked. The food need not be turned during grilling and because of the forced air circulation the food is evenly cooked. The temperature of the heating element may be lower than that of a conventional grill so that it will tend to have a longer life and there is also a reduced risk of fire when the oven is used compared to when a conventional grill is in use.

Various modifications to the embodiment described above may be made without departing from the invention. For example, instead of using a heating element whose limbs or coils are evenlv spaced with respect to the depth of the oven, the heating element could have limbs whose spacing increases or decreases with distance from the impeller so as to vary the heat transfer characteristics between the stream of air and the heating element. Instead of having the ribs 26 all the same size, they could be made of different sizes.

For example, the size of the ribs 26 could increase with increasing distance from the impeller. Instead of mounting the impeller on the rear wall of the oven it could be mounted on one side wall and this could be an advantageous layout if the opportunity were taken to position the motor behind the control panel of the oven. Instead of being a small free-standing table-top unit, the grill oven may be incorporated into a conventional freestanding cooker or into an oven unit for fitting into built-in kitchen furniture.

WHAT WE CLAIM IS: 1. An oven which may be used for grilling baking or roasting food by circulated hot air, which comprises an oven chamber defined by a roof, side walls, a floor, a rear wall and a hinged door, an electrical heating element positioned within the oven immediately below the roof in spaced parallel relationship thereto, an impeller for circulating air within the oven and in fluid communication therewith via an outlet duct opening to the oven close to its roof and an inlet duct also opening to the oven close to its roof but below the outlet duct, a tray which slidably engages support means within the oven so that it may be inserted at a selected one of a plurality of vertical levels between the level at which the inlet duct opens to the oven and the level defined by the floor of the oven with the periphery of the tray closely spaced from the adjoining portions of the oven chamber to define an upper space which during grilling baking or roasting by circulated hot air is heated by the circulating air and a lower space which is substantially unheated thereby, and a baffle plate which fits within the oven below the heating element to conceal the heating element and define with the roof of the oven a flow passage along which air from the outelt duct is directed in heat-transferring contact with the heating element, the baffle plate being formed with spaced perforations and deflector ribs for deflecting some of the air downwardly into the space above the tray at intermediate positions along the flow passage.

2. An oven according to Claim 1 in which the baffle plate is removable to allow cooking by direct radiant heat.

3. An oven which may be used for grilling food by radiant heat or for grilling, baking or roasting food by circulated hot air, substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (3)

**WARNING** start of CLMS field may overlap end of DESC **. this could be an advantageous layout if the opportunity were taken to position the motor behind the control panel of the oven. Instead of being a small free-standing table-top unit, the grill oven may be incorporated into a conventional freestanding cooker or into an oven unit for fitting into built-in kitchen furniture. WHAT WE CLAIM IS:

1. An oven which may be used for grilling baking or roasting food by circulated hot air, which comprises an oven chamber defined by a roof, side walls, a floor, a rear wall and a hinged door, an electrical heating element positioned within the oven immediately below the roof in spaced parallel relationship thereto, an impeller for circulating air within the oven and in fluid communication therewith via an outlet duct opening to the oven close to its roof and an inlet duct also opening to the oven close to its roof but below the outlet duct, a tray which slidably engages support means within the oven so that it may be inserted at a selected one of a plurality of vertical levels between the level at which the inlet duct opens to the oven and the level defined by the floor of the oven with the periphery of the tray closely spaced from the adjoining portions of the oven chamber to define an upper space which during grilling baking or roasting by circulated hot air is heated by the circulating air and a lower space which is substantially unheated thereby, and a baffle plate which fits within the oven below the heating element to conceal the heating element and define with the roof of the oven a flow passage along which air from the outelt duct is directed in heat-transferring contact with the heating element, the baffle plate being formed with spaced perforations and deflector ribs for deflecting some of the air downwardly into the space above the tray at intermediate positions along the flow passage.

2. An oven according to Claim 1 in which the baffle plate is removable to allow cooking by direct radiant heat.

3. An oven which may be used for grilling food by radiant heat or for grilling, baking or roasting food by circulated hot air, substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.