GB2349457A

GB2349457A - Cooking appliance

Info

Publication number: GB2349457A
Application number: GB0009427A
Authority: GB
Inventors: Mark Neil Hope; Gregory Robert Carns
Original assignee: Stoves Group PLC
Current assignee: Stoves Group PLC
Priority date: 1999-04-30
Filing date: 2000-04-18
Publication date: 2000-11-01
Anticipated expiration: 2020-04-18
Also published as: GB0009427D0; GB2349457B

Abstract

A cooking appliance has a control panel (106) mounted above a door (103) to an oven (304). A duct (211) is located above the oven and a fan (209) is mounted at the rear end of the duct, adjacent to an air inlet (210). A number of outlets (108) to the duct are provided below the control panel. In use, the fan provides a flow of air through the duct (211) and out of outlets (108). The flow of air transports heated air from the duct (211) and steers heated air rising from the door (103) away from the control panel (106). By arranging for the fan to be specific to this purpose, the throughput of air required is reduced compared to that of existing appliances. The fan is preferably an axial flow fan. The fan is activated by the activation of the oven heating means. The duct (211) may be located below a gas hob.

Description

A Cooking Appliance The present invention relates to a cooking appliance in which the control panel is cooled by directed air.

In order to perform their function, ovens produce heat and some is inevitably lost to the surrounding parts of the cooker. If some parts become hot, they may present a hazard to the user or, if the parts themselves are sensitive to temperature, they may become damaged by the heat. In order to control temperatures of particular parts of cookers, it is known to provide chambers and ducts around the oven cavity, or cavities, into which cooling air is pumped in or'sucked through'by fans. An example of such a system is described in United Kingdom Patent 2 255 632. However, this system uses blown air to cool many surfaces in the cooker and, as a result, a powerful fan is required to produce the necessarily large throughput of air. If a cooker of this kind is used, the user will become aware of the large quantity of warmed air blowing into the kitchen, but if the throughput of air were to be reduced, then the emergent air would become too hot.

According to a first aspect of the present invention there is provided a cooking appliance having an oven cavity with heating means; an outer panel located at the rear of said cooking appliance ; a duct above said oven cavity having an inlet located in said outer panel at a first end of said duct, and at least one outlet at said second end of said duct; a fan located at said first end of said duct and aligned with said inlet ; and control means for controlling said heating means, said control means being located at a second end of said duct; wherein when said fan is activated, said fan draws air into said duct; and said duct is configured such that substantially all air drawn through said inlet passes through said outlet.

The invention therefore provides a means for cooling the control means of the cooking appliance such that only a small throughput of air is required.

According to second aspect of the present invention there is provided a method of fabricating a cooking appliance having an oven cavity with heating means and control means for controlling said heating means, including the steps of attaching an outer panel to the rear of the cooking appliance; defining a duct above said oven cavity; providing an inlet, in said outer panel, at a first end of said duct; locating a fan at said first end of said duct such that said fan is aligned with said inlet and when said fan is activated, said fan draws air into said duct; locating said control means, at a second end of said duct; and providing at least one outlet at said second end of said duct, wherein said duct is configured such that when said fan is activated substantially all air drawn through said inlet passes out through said outlet.

The invention will now be described by way of example only with reference to the following drawings.

Figure an eiectric cooker which is fitted into kitchen furniture; Figure 2 provides a rear view of the cooker in Figure 1 ; Figure 3 provides a cross-sectional view of the installe cooker shown in Figure 1 ; Figure 4 shows a free-standing cooker which embodies the present invention.

Figure 5 provides an exploded view of the cooker in Figure 4.

Figure 6 provides a cross-sectional view of the cooker in Figure 4.

Figure 7 shows a detailed view of the top of the cooker as shown in Figure 6.

A domestic electric cooker 101, is shown in Figure 1, fitted into kitchen fumiture 102. The cooker has an oven door 103, which opens to allow access to an oven cavity where food may be cooked. When the oven is being used, heat escaping from the cooker will cause warming of the surrounding air. An optional air vent 104, has been fitted into work surface 105, to assist the removal of hot air from around the cooker.

A control panel 106, is situated directly above the oven door and contains various electrical components including a microchip within a digital clock 107. The control panel will also tend to warm up, as it is above the oven and the oven door. The temperature of the control panel needs to be kept below a predetermined limit, otherwise the control panel would become dangerously hot to handle and the heat would damage the electrical components it contains. In order to keep the control panel relatively cool, cooiing air is blown out of outlets 108.

A rear view of the cooker in Figure 1, is provided in Figure 2. The cooker has been removed from the kitchen furniture and part of back panel 201, which covers the top and rear of the cooker, has been cut away. The back panel is a single folded sheet of steel having a vertical portion 202, a horizontal portion 204 and an angled portion 203, orientated at an angle to the horizontal portion 204.

Altematively the horizontal portion may be made as a separate item to the back panel. Furthermore, the angled portion of the back panel may be made as a separate item to the vertical portion.

A chamber 205, behind the oven cavity, contains air which is warmed by heat leakage from the oven. Convection currents lift the warmed air, which escapes through upper holes 206, in the back panel. The warmed air is replace by cooler air drawn into the chamber, through lower holes 207 or base panel holes, described later with reference to Figure 3.

A safety cut-off switch 208, which is normally in the closed condition, is located on the back of the oven cavity. This will close and shut down the electricity supply to the oven if its temperature exceeds 300 C.

The angled portion 203, of the back panel, supports an axial fan 209 sold by Sunonwealth Electric Machine Co. Ltd., under Reference DP203A, Part Number 2123 LST. Fans of this type produce an air flow predominantly in the direction of the axis of rotation and so may be said to provide an axial flow. The fan is mounted on the inner surface of the back panel and is aligned with an air inlet 210 located in the angled portion of the back panel. It may be seen in Figure 2 and Figure 3 that the inlet has a diameter which approximates the distance across the fan's blades. Therefore the inlet provides little resistance to air flow when the fan is activated. When activated, the fan draws air into a duct 211. Sides of the duct are defined by a duct floor 212, side panels 213 and the horizontal portion 204 of the back panel. The side panels 213 constitute the outermost panels on either side of the appliance. The duct is therefore as wide as it may be, within the limits set by the dimensions of the cooking appliance and so the width of the duct is such that it provides little resistance to the flow of air when the fan is activated.

Air passing through the duct leaves through the outlets 108, in a front panel 214. The duct floor is a panel which is located in a horizontal plane above the oven cavity and extends continuously from the back panel to the front panel and between the opposing side panels.

The duct has, therefore, an upper wall defined by the horizontal portion 204 and a lower wall defined by the duct floor 212 which is also horizontal. Thus the upper and lower walls of the duct are parallel to each other. Since the duct is sufficiently large so as to contain the fan, it has a height which provides little resistance to the air flow caused by the fan when activated.

The height and width of the duct, the parallel nature of its sides and the large diameter of the inlet all provide for little resistance to air flow when the fan is activated. Furthermore, the only requirement of the fan is to produce a flow of air through the duct. It is not required to blow or suck air around a number of routes within the cooker, as is required of many fans in existing cooking appliances. The fan 209 is of a type that provides a volume of air flow that is just sufficient for this purpose. Therefore the invention allows a fan to be used which would have insufficient power in many similar existing applications.

The fan is activated by switching on the oven at the control panel or when the temperature of a thermostat 215, exceeds 70 C. The thermostat, which is mounted on the duct floor, is a temperature operated switch, that closes at temperatures above 70 C and re-opens when its temperature drops below 45 C. Therefore, once the temperature of the thermostat goes beyond 70 C, the fan will remain activated until the thermostat temperature drops below 45 C. This allows the fan to continue in operation after the oven has been switched off at the control panel.

In an alternative embodiment the fan is activated by switching on the oven and deactivated by switching the oven off. In a further alternative embodiment, a time delay circuit is included in the cooking appliance such that the fan is deactivated ten minutes after switching off the oven. Thus, the cooker has time to cool down before the fan is deactivated.

Figure 3 provides a cross-sectional view of the installed cooker shown in Figure 1. The cooker is resting on a plinth 301, above a kitchen floor 302, in front of a wall 303 and under the work surface 105.

In operation the oven cavity 304 is heated by one or more electric heating elements 305, and air is drawn into the duct 211 through the fan 209, from several sources. In this example an air vent 104, has been fitted into the work surface and provides a first source of air. A second source is provided by a gap 306, between the control panel and the work surface, which allows air to enter the fan via an upper space 307, above the cooker. A third source is provided by front apertures 308, which allow air to pass into a lower space 310, below the cooker. This air may then enter a backspace 311, behind the cooker, via rear apertures 309 or enter the chamber 205 via base panel holes 312. As previously mentioned, air movement within the chamber 205, takes place by convection and the air within the chamber will emerge through upper holes 206. All air emerging into the back space, behind the cooker may be drawn into the fan. The door 103, has an outer panel 313 and an inner panel 314, between which, there is a passageway 315, open at the top and at the bottom of the door. When the oven is operated, air within the passageway becomes warm and rises, escaping from the passageway at the top of the door. Cooler air is therefore drawn in at the bottom of the door, and by means of this convection current, the outer panel of the door is kept tolerably cool.

As indicated by Figure 3, duct 211, is substantially enclose, such that almost all of the air drawn in through inlet 210, by fan 209, flows through the duct 211 and passes out through outlets 108, situated below the control panel 106. Therefore, the majority of the air, drawn in through the fan, is used to transport away the heat escaping from the top of the oven. As a result, the temperatures of the duct floor and the rear of the control panel are kept below predetermined limits.

The outlets 108, are positioned below the control panel and just above the top edge of the door. This allows the air exiting the duct, through the outlets, to keep the front of the control panel cool. Hot air rising from the front of the oven, particularly from the passageway in the oven door, is steered away from the control panel by the relatively cool air leaving the duct.

A free-standing cooker providing an alternative embodiment of the present invention is shown in Figure 4. The cooker has two electrically heated oven cavities, each having a corresponding oven door 401 and 402.

On the top of the cooker is an arrangement of gas hobs 403. In an alternative embodiment the gas hobs may be replace with electric hobs. A control panel 404 is located above the upper oven door 401. Control knobs 405 are located on the control panel 404, and they are used to control the ovens and the gas hobs. During use the hot air rising from the oven cavities through oven doors 401 and 402 rises and tends to heat up the control knobs 405. An air outlet 406 is located below the controls so that cooling air may be blown through for the purpose of cooling the control knobs 405.

An exploded view of the cooker in Figure 4 is provided in Figure 5. A hob plate 501 which supports gas bumers 502 and pan supports 503 has been removed to provide a view of a duct 504 in the top of the cooker. An axial fan 505 is located at the rear of the duct 504 and adjacent to an inlet 506. The axial fan 505 is sold by Sunonwealth Electric Machine Company Limited under reference DP203A, part number 2123LST. The fan 505 is an axial fan which is mounted on to the rear plate 507 of the cooker. When operated, the fan 505 has the effect of drawing air through the inlet 506, which is then blown through the duct 504 and out through the outlet 406.

It may be seen if Figure 5 that the duct has sides defined by left and right sides of the cooker 508, the hob plate 501 and a duct floor 509.

A cross-sectional view of the cooker in Figure 4 is provided in Figure 6. The lower oven cavity 601, which has the door 402, is electrically heated by means of heating element 602. The upper oven cavity 603, which has upper oven door 401, is electrically heated by means of heating elements 604 and 605. The heating element 605 may be used for the purposes of grilling food, and so the oven cavity 603 may also be used as a grilling cavity.

The duct 504 is located above the upper oven cavity 603. At the rear end of the duct 504 is located the axial fan 505 and at the opposite end of the duct is located the air outlet 406. The air outlet 406 is located directly beneath the control panel 404 on to which are mounted the controls. The control knobs 405, by which means the controls may be manually adjusted, are located in front of the control panel 404. A part of the controls is located at the rear of the control panel 404 and within the duct 504. A rear part of a control 606 is shown in Figure 6, and this includes electrical components for the purpose of controlling the electrical supply to heating element 602.

An enlarged view of the top of the cooker shown in Figure 6 is provided by Figure 7. When either of the two oven cavities are heated, the fan 505 is automatically activated. In Figure 7, the upper cavity is being heated and so the fan has been activated. This has the effect of drawing air in through the fan as indicated by arrows 701, blowing air through the duct 504 and out through the outlet 406 as indicated by arrows 702. The door 401 has an inner and outer panel separated by a passageway 703. Air within the passageway 703 becomes heated by heat escaping from the oven cavity 603. The heated air within the passageway 703 is able to escape from the top of the door since the passageway is open at the top and bottom of the door. Air in contact with the front surface 704 of the door is also heated by heat escaping from oven cavity 603. Heat escaping from the passageway of the door and air heated at the front surface of the door tends to rise up towards the control knobs 405. However, air passing through outlets 406 and indicated by arrows 702 steers the heated air away from the control knobs.

The air within the duct 504 is warmed by heat escaping from oven cavity 603 through the duct floor 509. By blowing air through the duct 504, the whole of the duct, which is hatched, is cooled. The rear part of the controls such as a part 606, are therefore surrounded by air which is cooler than would otherwise be. Electrical components within the controls, therefore operate at temperatures lower than they otherwise would. This has the effect of increasing the reliability and life of the electrical components.

Claims

1. A cooking appliance having an oven cavity with heating means; an outer panel located at the rear of said cooking appliance ; a duct above said oven cavity having an inlet located in said outer panel at a first end of said duct, and at least one outlet at said second end of said duct; a fan located at said first end of said duct and aligned with said inlet ; and control means for controlling said heating means, said control means being located at a second end of said duct; wherein when said fan is activated, said fan draws air into said duct; and said duct is configured such that substantially all air drawn through said inlet passes through said outlet.

2. A cooking appliance according to claim 1, wherein said fan is attached to said outer panel.

3. A cooking appliance according to claim 1 or claim 2, wherein side panels of said cooking appliance define sides of said duct.

4. A cooking appliance according to any of claims 1 to 3, wherein said duct has an upper wall and a lower wall and said walls are substantially parallel.

5. A cooking appliance according to any of claims 1 to 4, wherein said fan is mounted on the inner surface of said outer panel.

6. A cooking appliance according to any of claims 1 to 5, wherein said fan is configured to provide axial flow.

7. A cooking appliance according to any of claims 1 to 6, wherein said fan is activated by the activation of said heating means.

8. A cooking appliance according to any of claims 1 to 7, wherein a part of said control means is located within said duct.

9. A cooking appliance according to any of claims 1 to 8, wherein said outlet is located below said control means and above said oven cavity.

10. A cooking appliance according to any of claims 1 to 9, wherein said cooking appliance is a cooker configured to be located within kitchen furniture.

11. A cooking appliance according to claim 10, wherein said oven cavity has a door, said door having an inner panel and an outer panel spaced apart by a passageway, in which said passageway is cooled by convection currents.

12. A cooking appliance according to claim 10 or claim 11, wherein said fan is activated by temperature sensing means.

13. A cooking appliance according to any of claims 10 to 12, wherein said cooking appliance includes a chamber behind said oven cavity, said chamber being cooled by convection currents.

14. A cooking appliance according to any of claims 10 to 13, wherein said duct has an upper wall which is a portion of an outer panel of said cooking appliance.

15. A cooking appliance according to any of claims 1 to 9, wherein said cooking appliance includes a plurality of hobs disposed above said duct.

16. A cooking appliance according to claim 15, wherein said hobs are supported by a hob plate and said hob plate defines an upper side of said duct.

17. A cooking appliance according to claim 15 or claim 16, wherein said hobs includes gas burners.

18. A method of fabricating a cooking appliance having an oven cavity with heating means and control means for controlling said heating means, including the steps of attaching an outer panel to the rear of the cooking appliance ; defining a duct above said oven cavity; providing an inlet, in said outer panel, at a first end of said duct; locating a fan at said first end of said duct such that said fan is aligned with said inlet and when said fan is activated, said fan draws air into said duct; locating said control means, at a second end of said duct; and providing at least one outlet at said second end of said duct, wherein said duct is configured such that when said fan is activated substantially all air drawn through said inlet passes out through said outlet.

19. A method of fabricating a cooking appliance according to claim 18, including the step of attaching said fan to said outer panel.

20. A method of fabricating a cooking appliance according to claim 18 or claim 19, including the step of attaching side panels to said cooking appliance, such that said side panels define sides of said duct.

21. A method of fabricating a cooking appliance according to any of claims 18 to 20, wherein said duct is provided with an upper wall and a lower wall which are substantially parallel.

22. A method of fabricating a cooking appliance according to any of claims 19 to 21, wherein said fan is mounted on the inner surface of said outerpanel.

23. A method of fabricating a cooking appliance according to any of claims 18 to 22, wherein said fan is configured to provide axial flow.

24. A method of fabricating a cooking appliance according to any of claims 18 to 23, wherein said fan is configured to be activated by the activation of said heating means.

25. A method of fabricating a cooking appliance according to any of claims 18 to 24, wherein a part of said control means is located within said duct.

26. A method of fabricating a cooking appliance according to any of claims 18 to 25, wherein said outlet is located below said control means and above said oven cavity.

27. A method of fabricating a cooking appliance according to any of claims 18 to 26, wherein said cooking appliance is configured to be located within kitchen furniture.

28. A method of fabricating a cooking appliance according to claim 27, including the step of providing said oven cavity with a door having an inner panel and an outer panel spaced apart by a passageway.

29. A cooking appliance according to claim 27 or claim 28, wherein said fan is configured to be activated by temperature sensing means.

30. A method of fabricating a cooking appliance according to any of claims 27 to 29, including the steps of defining a chamber behind said oven cavity, and configuring said cooking appliance such that said chamber is cooled by convection currents when said oven is used.

31. A method of fabricating a cooking appliance according to any of claims 27 to 30, including the step of attaching an outer panel to said cooking appliance, such that said outer panel defines an upper wall of said duct.

32. A method of fabricating a cooking appliance according to any of claims 18 to 26, including the step of locating a plurality of hobs above said duct.

33. A method of fabricating cooking appliance according to claim 32, including the step of locating a hob plate above said duct, such that said hob plate defines an upper side of said duct.

34. A method of fabricating a cooking appliance according to claim 32 or claim 33, wherein said hobs includes gas burners.

35. A cooking appliance substantially as herein described with reference to Figures 9 to 3, or to Figures 4 to 7.

36. A method of manufacturing a cooking appliance substantially as herein described with reference to Figures 1 to 3, or to Figures 4 to 7.