GB2190486A - Air flow insulated ovens - Google Patents

Abstract

An oven assembly 1 comprises an oven having a front access opening and being enclosed by side, rear, and upper cladding elements 9, 11. The oven is positioned within the assembly such that an upper space is defined between the oven and the upper cladding element, a lower space is defined between the oven and the bottom of the assembly, and side spaces 10 are defined between the side cladding elements 9 and the sides of the oven. The side spaces 10 define air flow chambers providing communication between the upper space and lower space.The lower space has an air inlet and the upper space has an air outlet. In use of the assembly, heat from the oven causes air to be drawn through the inlet into the lower space, to pass through the chambers 10 into the upper space and to be exhausted through the outlet. The assembly preferably also includes a vaned exhaust chamber 14 and a flue 20. <IMAGE>

Description

SPECIFICATION An oven The present invention relates to an oven assembly.

There is a growing demand for small gas cookers (incorporating ovens) such as in caravans, boats, one-person flats etc. The ovens of such cookers incorporate a burner but there is generally no thermostatic control. The ovens are however required to comply with relevant British Standards with regard to 'heat-up' time, i.e. the time required for the oven to heat to a particular temperature. To comply with these Standards, a rapid heat inputfrom the burner is required. It is also general practice to insulate the oven to preventthe external surfaces of the oven from unwanted heating which could be dangerous and result in burns to people who accidentally touch these surface.Howeverthis insulation causes an undesirable increase in the maximum temperature of the because, in the absence of a thermostat, the burner continues its heat inputto the oven giving rise to a higher centre oven temperature which also leads to higher external temperatu res for the oven.

It is an object of this invention to obviate or mitigatetheabovementioned disadvantage.

According to the present invention there is provided an oven assembly comprising an oven having a front access opening and being enclosed by side, rear and upper cladding elements, said oven being positioned within the assembly so that an upper space is defined between the oven and the upper cladding element, a lower space is defined between the oven and the bottom of the assembly, and said side spaces are defined between the side cladding elements and the sides of the oven, said side spaces defining air flow chambers providing communication between said upper and lower spaces, said lower space being associated with an air inlet, and said upper space being associated with an air outlet whereby in use of the assembly heatfrom the oven causes air to be drawn through the inlet into the lower space, to pass through said chambers into the upper space, and to be exhausted through the outlet.

The provision ofthe side chambers allows air to pass up the sides of the oven thereby ensuring that the outer surfaces of the assembly do not become too hot. Nevertheless, the lackofinsulation panels at the sides of the oven ensures that rapid heat up times are possible.

It is preferred that the oven has a secondardy aerated burnerand it is also highly preferred to provide a vaned exhaust chamber within the assembly on the top ofthe oven. The interior ofthe oven will communicate with the chamberthrough which a portion of the hot gases from the oven will follow a tortuous path to effect a degree of cooling thereof. The vaned exhaust chamber preferably has an outlet aperture in its upper surface. Preferably this upper outlet aperture communicates with a flue extending acrossthe upperspace. Such afluemay have an inlet atthe rear of the assembly and an outlet atthefrontthereof. Gases from the oven pass into the flue (after passing through the exhaust chamber) and are further cooled by entrained air drawn through the inlet of the flue.

The provision of the flue makes it possible forthe airoutletforthe upper space to be provided at the frontofthe assembly since all gases passing through the outlet will be comparatively cool so there is no dangerto a person stood atthefrontoftheoven.

This air outlet may be provided as a grill on a fascia panel which (because there are no hot gases) may be of plastics material. The controlsforthe oven may be mounted on this fascia panel.

The invention will be further described byway of example onlywith reference to the accompanying drawings in which: Figure lisa partially cut-away perspective view of one embodiment of oven assembly in accordance with the invention; Figure 2 is a part sectional plan view ofthe assembly shown in Figure 1 taken on the line ll-ll of Figure.

Figure 3 is a sectional view along the line Ill-Ill of Figure 2; and Figures 4and 5showvarious constructions of cooker based on the oven assembly of the invention.

The oven assembly 1 illustrated in Figure 1 comprises an open-fronted pre-fabricated oven box 2 mounted on two front corner extrusions 3 and two rear corner extrusions 4. Front extrusions 3 each have four mutually perpendicular limbs 3a-d with limbs 3a and 3e bei ng off-set from each other as are limbs 3b and 3d. Rearextrusions 4 are simply L-shaped (with limbs 4a and 4b).

Box 2 is open-fronted but is otherwise defined by upper, lower and rear sides designated as 2u, 21, 2s and 2r respectively. Rear side 2r is of a heightgreater than the height of sides 2s, as will be seen from Figure 1. Front corner flanges 5 are formed at each vertical front corner edge of box 2, and similar flanges 6 are provided as the rear vertical corner edges (see also Figure 2). These flanges 5 and 6 project outwardly of box 2 at right angles to the sides 2s.

In the assembly of the unit 1 ,the rear extrusions 4 are arranged such that one limb 4a is directed towards the front of the unit 1 whereas the front extrusions 3 are arranged such thattheir limbs 3b point to the rear of the unit, the outer surfaces ofthe limbs 3b and 4a being flush with each other. The front flanges 5 of the oven box 2 are affixed to the front surfaces of arms 3a (of extrusions 3) whereas the rearflanges 6 are affixed (e.g. by bolts-not shown) to the rear surfaces of limbs 4b (of extrusions 4).

It should at this point be noted that extrusions 3 and 4 are of a length greater than the height of box 2 whereby they project both above and belowthe box.

Thus with the oven unit stood on a level surfacethere is a space 7 below the lowerface 21 of the box 2.

Similarly, there is a space 8 above the oven-box 2.

Any required electrical equipment (not shown) for the oven may be located in space 7.

Side panels 9 are provided at each side ofthe assembly 1 and are affixed to the outer surfaces of the limbs 4a (of extrusions 4) and the limbs 3b (of extrusions 3). Thus these panels 9 extend overthe full height of extrusions 3 and 4 and define chambers 10 (communicating with spaces 7 and 8) between themselves and the sides 2s of box 2.

The rear of assembly 1 is formed from a panel 11 and insulation 12 is provided between this panel and the rear side 2r ofthe oven box 2, which, as mentioned above, is of greater heightthan the sides 2s. Upwardly projecting bounding flanges 13 are provided atthe top of box 2 and define a shallowtray in which a vaned exhaust chamber 14(see below) is a close fit. Provided towards thefront ofthe upperside 2u of box 2 is an aperture 15 and a similar aperture 16 is provided towards the rear. A further aperture 17 is positioned towards the rear of the lower side 21 of box2adjacentasecondaryaerated gas burner (not shown)-seeFigure3.Finally, (although not illustrated in the drawings) box 2 is clad with reflective aluminium foil (whereofthe 'shiny' surface is in contact with the outer surface of the box.

The vane exhaust chamber 14 has two lower apertures 1 8 each of which registers with an aperture 15 or 16 in the upper side 2u of the oven-box 2. The upperface of exhaust chamber 14 has a single aperture 19. Within chamber 14 (although not specifically illustrated in the drawing) are a plurality of vanes or baffles which define a tortuous fluid flow path for gases passing through the chamber 14from aperture 18 to outlet aperture 19.

An L-shaped flue 20 of width narrowerthan that of oven-box 2 has one limb 20a extending within upper space8 overthetop of chamber 17 and its other limb 20b extending partway down the rear of the assembly 1 .The panel 11, insulation 12 and rearside 2r of the oven have upper cut-out portions which allowtheflueto be located in the position illustrated.

Limb 20a is open towards its rear undersurface and has flanges 21 arranged such that all gases from aperture 19 pass into the flue 20. The limb 20b is open at its lower end, as clearly illustrated in Figures 1 and 3.

The limb 20a offlue 20 extends to the front of oven-box 2 and its front end lies against a plastics frontfascia panel 21 (supported on the extrusions 3) having a grill formation 22 which extends across the beyond the sides of limb 20a.

The illustrated oven unit is provided with a top panel 23 (having internal insulation not shown) and will also have a lower grill (not shown) across the front of space 7).

In operation ofthe illustrated oven unit 1, several airflow pathways are generated.

Firstly, the chamber 10 at the side ofthe unit 1 will be heated by the oven box 2 with resultant upward convection ofairthroughthese chambers. This results in an airflow pathway in the direction of arrows A, i.e. air enters the space 7 below the oven box 2, passes upwardly through the side chambers 10 and into the space 8 before passing along the sides of limbs 20a offlue 20 and exiting through the grill 22 (see Figure 1).

It should also be noted that a portion ofthe air entering lowerspace7 passes through aperture 17 in the lower side 21 of the oven-box and serves to aerate the burner.

Secondly, there isthe normal air circulation within the heated oven (arrows B). Thirdly, some ofthe heated airwithinthe oven passes through apertures 15 and 16 in the top of the oven-box into the vaned exhaust chamber 14within which the air follows a tortuous path (the general flow direction being depicted by arrows C) before exiting through aperture 19 into flue 20.

Fourthly, the flow of airfrom aperture 19 serves two entrain cool air which enters flue 20 (arrows D) through the lower end of its limb 20b. This cool air mixes with the warm air entering fluid 20 via aperture 19 and provide additional cooling before the air exits through fascia panel 21.

It should be appreciated that the illustrated oven assembly has a number of advantages. Firstly, all gases exiting throughtthe grill 22 are comparatively cool (allowing a plastics grill to be used) and do not pose a danger two a user of the cooker. Since the grill is maintained cool, it is possible to mount controls for the oven directly onto the fascia panel 21.

Secondly the provision ofthe chambers 10 atthe sides ofthe assembly avoid the need for substantial insulation at the sides of the assembly. The absense of side insulation, coupled with the reflective foil provided around the oven box 2, provide for rapid heat up times of the oven.

Figures4and5illustratetwoembodimentsof cooker based on the oven assembly of the invention.

Claims (14)

1. An oven assembly comprising an oven having a front access opening and being enclosed by side, rearand upper cladding elements, said oven being positioned within the assembly so that an upper space is defined between the oven and the upper cladding element, a lower space is defined between the oven and the bottom of the assembly, and side spaces are defined between the side cladding elements and the sides ofthe oven, said side spaces defining airflow chambers providing communication between said upper and lower spaces, said lower space being associated with an air inlet, and said upper space being associated with an air outlet whereby in use of the assembly heat from the oven causes air to be drawn through the inlet into the lower space, to pass through said chambers into the upper space, and to be exhausted through the outlet.

2. An oven assembly as claimed in claim 1, having an exhaust chamber positioned on top ofthe oven, said chamber being in communication with the interior of the oven, and said exhaust chamber having an outlet and having interiorvanes or baffles to direct the flow of gas passing through the chamberto its outlet.

3. An oven assembly as claimed in claim 2, wherein the upperside of the oven has a first aperture positionedtowardsthefrontofthe oven and a second aperture positioned towards the rear of the oven, and said exhaust chamber is a box-like structure with two apertures in the lower side thereof, said two apertures ofthe exhaust chamber each registering with one aperture of the oven.

4. An oven assembly as claimed in claims 2 or3, having a flue extending through said space above the oven, the flue has an inletforambientairandan air outlet, and the interior of the exhaust chamber communicates with said flue.

5. An oven assembly as claimed in claim 4, wherein the flue inlet is at or towards the rear ofthe assembly and the flue outlet is at the front ofthe assembly.

6. An oven assembly as claimed in claim 5, wherein the flue is generally L-shaped whereof a first limb extends downwardly behind the oven and is open at its lower end to provide said flue inlet and the second limb extends through said space above the oven.

7. An oven assembly as claimed in claim 6, wherein a portion of the lower side of said second limb is open and the portion is located over an aperture in the top of said exhaust chamber thereby providing said communication between the exhaust chamber and the interior oftheflue.

8. An oven assembly as claimed in claim 1, having a flue extending through said space above the oven, the flue has an inlet for ambient air and an air outlet, and interior ofthe oven communicates with said flue.

9. An oven assembly as claimed in claim 8, wherein theflue inlet is at ortowards the rear ofthe assembly and the flue outlet is at the front of the assembly.

10. An oven assembly as claimed in claim 9, wherein the flue is generally L-shaped whereof a first limb extends downwardly behind the oven and is open at its lower end to provide said flue inlet and the second limb extends th rough said space above the oven.

11. An oven assembly as claimed in any one of claims 1 to 10, wherein the front of the upper space is covered by a grill in which the air outletforthe upper space is provided.

12. An oven assembly as claimed in claim 11, when dependent on any one of claims 5 to 10, wherein the outlet of the flue locates behind said grill.

13. An oven assembly as claimed in any one of claims 1 to 12, wherein the oven has a secondary aerated burner.

14. An oven assembly substantially as hereinbefore described with reference to Figures 1 to 3, or Figure4 or Figure 5 of the accompanying drawings.