GB2144846A

GB2144846A - Gas cooking appliances

Info

Publication number: GB2144846A
Application number: GB08316990A
Authority: GB
Inventors: Arthur Floyd
Original assignee: TI Domestic Appliances Ltd
Current assignee: TI Domestic Appliances Ltd
Priority date: 1983-06-22
Filing date: 1983-06-22
Publication date: 1985-03-13
Also published as: GB8316990D0; GB2144846B

Abstract

A gas cooking appliance has a grill chamber (1) which can also be used as an oven, the grill chamber (1) having a grill burner located therein adjacent the roof (14) thereof, and an oven burner (11) housed in a combustion chamber (3). A substantial proportion of the grill chamber floor (2) is heated by the oven burner (11), the products of combustion of which are discharged from the combustion chamber (3) via an opening (9) into the grill chamber (1). The products of combustion travel forwardly towards an opening (27) in a partition (25) supported below the grill burner and flow towards an exhaust flue (18) via a space between the roof of the grill chamber (1) and the partition (25). When used for grilling, the partition (25) rests on the floor (2) of the grill chamber (1) in an inverted position and provides location for a grill pan (33), and fumes flow directly to exhaust (18). <IMAGE>

Description

SPECIFICATION Gas cooking appliances This invention relates to gas cooking appliances and has particular although not exclusive reference to gas cooking applicances for domestic use.

Many conventional gas cooking appliances have a grill chamber sometimes but not always located beneath the top burners of the appliance in which culinary grilling operations are carried out. Such grill chambers are usually of relatively small capacity. Baking, roasting and similar cooking operations are carried out in the oven of the cooking appliance, the capacity of the oven being substantially greater than that of the grill chamber although for many such cooking operations that larger capacity is not required. It would be an advantage if the grill chamber of a gas cooking appliance could be used also as a small capacity oven but this has not previously been successfully accomplished because of difficulties encountered in obtaining the even heating of the grill chamber which is necessary for its successful use as a small oven.

According to the present invention, a gas cooking appliance has a grill chamber with an entrance at one end, a roof and a floor, a grill burner, and, to enable the grill chamber to be used as an oven, an oven burner located in a combustion chamber having a roof extending over a substantial part of the grill chamber, the oven burner being arranged to heat the roof of the combustion chamber and to discharge its products of combustion into the grill chamber at the other end thereof, an exhaust system for exhausting combustion products from the grill chamber to atmosphere, and means for adapting the exhaust system according to whether the grill burner or the oven burner is to be used.

The combustion chamber may be positioned beneath the floor of the grill chamber, the floor then forming the roof of the combustion chamber.

The combustion chamber may extend from adjacent the entrance to adjacent the other end of the grill chamber, the oven burner being positioned in the combustion chamber adjacent the entrance and, in use, firing towards an outlet, at the other end of the combustion chamber, for combustion products, the outlet communicating with the grill chamber at the other end thereof.

In one embodiment of the invention, the exhaust system includes a combustion products exhaust located at the other end of the grill chamber and sized to accommodate combustion products from the grill burner, and in which the means comprises a removable partition with an opening adjacent one edge thereof and sized to determine the flow of the combustion products from the oven burner to the exhaust, means being provided within the grill chamber for supporting the partition below the roof of the grill chamber with the opening adjacent the entrance and in a position that prevents access to the exhaust except via the opening and a space between the roof of the grill chamber and the partition.

In another embodiment of the invention, the exhaust system includes a first combustion products exhaust located at the other end of the grill chamber and sized to accommodate combustion products from the grill burner and a second combustion products exhaust located at the one end of the grill chamber and sized to determine the rate of flow of combustion products of the oven burner from the chamber and means for closing a selected one of the first and second exhausts according to whether the oven burner or the grill burner is to be used.

Each exhaust may incorporate a butterfly valve operatively linked in such manner to gas supply control means for controlling the supply of gas to the grill and oven burners that actuation of the supply control means to supply gas to one of the burners effects closure of the exhaust of the other burner.

In those embodiments which incorporate a removable partition, the latter may be supported adjacent the grill burner between the latter and the interior of the grill chamber.

Preferably, in that case, the grill burner is of the surface combustion type.

The partition may have a transverse ridge adjacent the opening which, when the partition is supported by the support means, extends downwardly into the interior of the grill chamber.

The partition may also have a platform at one end thereof remote from the opening, the platform also extending downwardly into the interior of the grill chamber when the partition is supported upon the support means.

By way of example only, a grill chamber suitable for use also as an oven will now be described in greater detail with reference to the accompanying drawings of which: Figure 1 is a section in diagrammatic form of the chamber in use as a grill chamber, and, Figure 2 is a section in diagrammatic form of the chamber in use as an oven.

The drawings show a grill chamber 1 that is positioned below the top burners (not shown) of a gas cooking appliance and above the main oven (not shown) of the cooking appliance.

The grill chamber 1 has a removable floor member 2 below which is a combustion chamber 3 of elongate tray-like form having a floor 4, side walls, a front wall 5 with rows of air inlet apertures 6, 7 and a rear wall 8. The floor member 2 acts as a roof for the combustion chamber 3. The rear wall 8 of the combustion chamber 3 slopes upwardly as shown towards an exit 9 formed between an up turned lip 10 at the inner end of the floor member 2 and the upper end of wall 8. Seen in plan, the combustion chamber 3 is rectangular and extends across almost the full width of the grill chamber.

Housed in combination chamber 3 adjacent front wall 5 is a gas burner 11 acting as an oven burner with a burner mouth 1 2 of elon gate form extending across the full width of the combustion chamber. The mouth 1 2 of the oven burner 11 faces towards the rear wall 8.

The oven burner 11 is fed from a header 1 3 and is spaced from the floor 4 to allow the circulation of secondary air both above and below the burner mouth 1 2.

The roof 14 of the grill chamber 1 is stepped as at 1 5 to accommodate a grill burner 1 6 of the surface combustion type, the mesh surface of the burner being indicated at 1 7. Towards its inner end, the roof 14 of the grill chamber 1 slopes upwardly towards the entrance 1 8 of an exhaust flue (not shown) through which combustion products pass to atmosphere. The roof 14 of the grill chamber 1 is also apertured at 1 9 to allow passage of an operating lever 20 of a safety interlock system associated with the gas taps controlling the flow of gas to the oven burner 11 and grill burner 16.

The detail of the safety interlock system is found in the Specification of co-pending U.K.

Patent Application No. 8316989 and will not be described further herein. The principal function of the interlock is to allow a user to operate only the gas valve controlling the grill burner 1 6 when a grilling operation is to be carried out, and only the gas valve controlling the oven burner 11 and when chamber 1 is used as an oven.

Both burners are supplied with gas via a gas rail 21, the valves being mounted on the undersurface of the rail. One such valve is shown in the drawings under reference 22.

The grill chamber 1 has a door 23 hinged along its lower edge to the main structure of the cooker and movable between a fuliy-open position shown in Fig. 1 and a fully closed position shown in Fig. 2. A sealing strip 24 round the entrance to the chamber 1 prevents ingress of air into the latter when the door 23 is fully closed.

Fig. 1 also shows a partition 25 resting on the floor member 2. The partition 25 is of generally rectangular form with a lip 26 at one end and a transverse opening 27 located between the lip 26 and an adjacent transverse ridge 28. The function of the opening 27 will be described below. At its other end, the partition has a locally raised portion 29 with an inclined front wall 30 and curved end wall 31. When in the position shown in Fig. 1, the raised portion 29 seats over the upturned lip 10 so closing the opening 9 effectively, that action being assisted by the curved wall 31.

When a grilling operation is to be carried out, the food to be grilled is placed on a grill tray 32 of a grill pan 33 and the latter is inserted into the chamber 1 until the end of the pan 33 abuts the inclined wall 30. In that position, the grill pan 33 is located directly beneath the grill mesh 17. To and fro move ment of the grill pan is limited by the ridge 28 and the wall 30.

The door 23 cannot be closed fully during a grilling operation because operation of the interlock system has resulted in lever 20 be ing pivoted to and held in the position shown in Fig. 1 and the door 23 comes into contact with the end of the lever before the closed position is reached. The door is so mounted that if a user, having moved the door to the position shown in dotted lines in Fig. 1, then releases the door, it returns to its fully opened position.

During grilling, radiant heat is emitted from the burner 1 6 as indicated by arrows 34 to grill food on grill tray 32 while products of combustion leave the grill chamber via the entrance 1 8 of the exhaust flue as indicated by arrows 35.

When it is desired to use the grill chamber 1 as an oven, the grill pan 33 and the partition 25 are removed. The partition 25 is then inverted and re-inserted into the grill chamber adjacent the burner 1 6 as shown in Fig. 2. The partition 25 is supported upon side runners not shown in Fig. 2. The aperture 9 is now exposed and access to the entrance 1 8 is permitted only by way of transverse opening 27 and the space between the partition 25 and the roof 14.The crosssectional area of the slot 27 is less than that of the entrance 1 8 thereby effectively restricting the latter to a value appropriate to the thermal output of the burner 1 2. As the partition is inserted, the lip 26 now extending upwardly contacts the lower end of the lever 20 and withdraws it into the chamber allowing the door 23 to be fully closed at the commencement of a cooking operation as an oven so preventing the ingress of air via this route.

The gas valve controlling the oven burner is then operated and gas leaving the latter is ignited. Secondary air for combustion is drawn into the combustion chamber 3 via the rows of apertures 6 and 7 and flows forwardly above and below the burner mouth 1 2. Radiant heat from the burner flames, diluted to some extent by cool air from inlets 6, heats a substantial proportion at least of the floor member 2 of the grill chamber as indicated by the arrows 36. Combustion products flow along the combustion chamber 3 to the opening 9 from whence they are discharged into the grill chamber 1 at the inner end thereof.

The flow of combustion products is turned towards the outer end of the grill chamber 1 by the rear wall 37 of the latter as indicated by arrow 38, the flow moving forwardly in proximity to the partition 25. On meeting the transverse ridge 28, the flow of combustion products is deflected downwardly and a part is drawn backwards as indicated by arrow 39, the remainder passing out of the grill chamber 1 via the opening 27 and flows to atmosphere via the space between the dome 25 and the roof 14 and exhaust duct as indicated by the arrow 40. The size of the opening 27 determines the rate of flow of combustion products of the oven burner from the grill chamber.

In that way, the interior of the grill chamber 1 is evenly heated and the grill chamber can be used efectivly as a small oven.

Even heating results from the use of an elongate combustion chamber beneath the floor member 2 of the grill chamber 1 and the positioning of the burner 11 at the outer end, and the combustion products outlet 9 at the inner end of the combustion chamber 3, together with the extended flow path for combustion products within the grill chamber 1 arising from the relative positions of the outlet chamber 1 arising from the relative positions of the outlet 9 and opening 27. Movement of combustion products from outlet 9 to opening 27 is guided by the partition 25.

The elongate form of the combustion chamber 3, that is to say the spacing of the burner mouth 1 2 from the aperture 9, allows adequate mixing of combustion products and secondary air together with a considerable reduction in the forward velocity of those products before they reach the opening 9.

The presence of the ridge 28 enhances the heating of the combustion products at the outer end of the grill chamber 1 by deflecting downwardly a portion of such products as indicated.

The partition 25 also shields the mesh surface 1 7 of the burner 1 6 from contamination by deposits that would otherwise occur as a result of cooking operations when the grill chamber 1 is used as an oven. The partition also limits considerably the extent to which the burner 1 6 will act as a flue by which combustion products may leave the grill chamber 1.

It is found that during a cooking operation involving the baking of a test arrangement of small cakes 41, all are evenly cooked and no over- or under-cooking of any cake occurs.

With other forms of grill burner, a shield is not as essential and the partition need not be located between the grill burner and the interior of the grill chamber 1 but could be located between the roof of the grill chamber 1 and the grill burner.

Combustion products may be ducted away from the grill chamber in ways other than that described above. For example, combustion products from the grill burner may be conveyed from the grill chamber via an opening at the rear thereof and sized to accommodate the combustion products from the grill burner.

Another opening located in the roof of the grill chamber adjacent the entrance thereof is provided to carry away combustion products of the oven burner and functions in a similar manner to opening 27 described above. Both openings are fitted with butterfly valves that are spring loaded into a position closing the aperture and interconnected to the gas taps controlling gas to the grill and oven burners in a manner such that actuation of one of the taps of a burner moves the butterfly valve of the opening associated with the selected burner to its open position.

It will be appreciated that the invention may be embodied in small, portable gas cooking appliances which heretofor have comprised simply one or two top burners and a grill chamber beneath them. By incorporating an oven burner as described above, the grill chamber may also be used as an oven.

The invention may also be embodied in the so-called "built-in" ovens.

Claims

1. A gas cooking appliance having a grill chamber with an entrance at one end, a roof and a floor, a grill burner, and, to enable the grill chamber to be used as an oven, an oven burner located in a combustion chamber having a roof extending through a substantial part of the grill chamber and arranged to heat the roof of the combustion chamber and to discharge its products of combustion into the grill chamber at the other end thereof, an exhaust system for exhausting combustion products from the grill chamber to atmosphere, and means for adapting the exhaust system according to whether the grill burner or the oven burner is to be used.

2. A gas cooking appliance as claimed in claim 1 in which the combustion chamber is positioned beneath the floor of the grill chamber.

3. A gas cooking appliance as claimed in claim 2 in which the combustion chamber extends from adjacent the entrance to adjacent the other end of the grill chamber, the oven burner being positioned in the combustion chamber adjacent the entrance and, in use, firing towards an outlet. at the other end of the combustion chamber, for combustion products, the outlet communicating with the grill chamber at the other end thereof.

4. A gas cooking appliance as claimed in claim 1, 2 or 3 in which the exhaust system includes a combustion products exhaust located at the other end of the grill chamber and sized to accommodate combustion products from the grill burner, and in which the means comprises a removable partition with an opening adjacent one edge thereof sized to determine the flow of combustion products from the oven burner to the exhaust, means being provided within the grill chamber for supporting the partition below the roof of the grill chamber with the opening adjacent the entrance and in a position that prevents access to the exhaust except via the opening and a space between the roof of the grill chamber and the partition.

5. A gas cooking appliance as claimed in claim 1, 2 or 3 in which the exhaust system includes a first combustion products exhaust located at the other end of the grill chamber and sized to accommodate combustion products from the grill burner, and a second combustion products exhaust located at the one end of the grill chamber and sized to regulate the flow of combustion products from the oven burner and means for closing a selected one of the first and second exhausts according to whether the oven burner or the grill burner is to be used.

6. A gas cooking appliance as claimed in claim 5 in which each exhaust incorporates a butterfly valve, and in which the butterfly valves are operatively linked in such manner to gas supply control means for controlling the supply of gas to the grill and oven burners that actuation of the supply control means to supply gas to one of the burners effects closure of the exhaust of the other burner.

7. A gas cooking appliance as claimed in claim 4 in which the support means support the partition adjacent the grill burner and between the latter and the interior of the grill chamber.

8. A gas cooking appliance as claimed in claim 7 in which the grill burner is of the surface combustion type.

9. A gas cooking appliance as claimed in claim 7 or 8 in which the partition has a transverse ridge adjacent the opening which, when the partition is supported by the support means extends downwardly into the interior of the grill chamber.

10. A gas cooking appliance as claimed in any one of claims 7, 8 or 9 in which the partition has a platform at one end thereof remote from the opening, the platform also extending downwardly into the interior of the grill chamber when the partition is supported upon the support means.

11. A gas cooking applicance having a grill chamber with an entrance at one end and an exhaust for combustion products at the other end, a grill burner located within the grill chamber adjacent the roof thereof, and, to enable the grill chamber to be used as an oven, an oven burner, in which the oven burner is housed in an elongate combustion chamber extending from adjacent the entrance to adjacent the other end of the grill chamber, the oven burner being positioned in the combustion chamber at that end thereof adjacent the entrance and, in use, firing towards a combustion product outlet at the other end of the combustion chamber, the combustion products outlet communicating with the interior of the grill chamber at the other end thereof, a removable partition with an opening at one end thereof, and means for supporting the partition beneath the roof of the grill chamber with the opening adjacent the entrance and in a position between the grill burner and the interior of the grill chamber which prevents access from the interior to the exhaust except via the opening and a space between the roof and the partition.

1 2. A gas cooking appliance having a grill/oven chamber substantially as herein described with reference to and as illustrated by the accompanying drawings.