GB2197457A - Cooking appliances - Google Patents

Abstract

To simplify and cheapen the construction of a cooking appliance, the latter comprises an oven chamber structure formed from panels. The oven structure is mounted directly upon an apertured front panel member (30) having an aperture (31) giving access to the interior of the oven chamber structure. The latter structure is also directly mounted upon outer side panels (39, 40) and is supported thereby and by the front panel member (30). An additional cooker chamber also of panel construction may also be provided and in this case the front panel member (30) has a second aperture (32) giving access to the interior of the additional chamber while is also secured directly to the front panel member (30) and the outer side panels (39, 40) which support it. <IMAGE>

Description

SPECIFICATION Cooking appliances and methods of manufacturing the same This invention relates to cooking appliances and to methods of manufacturing the same.

The invention has particular but not exclusive reference to cooking appliances for domestic use.

Domestic cooking appliances having an oven, grill chamber and/or second oven and top burners and/or electric heating units usually have a core framework or chassis to which are secured side panels and on which are mounted doors for the oven and grill chambers.

The need for the core framework or chassis adds to the cost of materials and also adds to production costs. The presence of the core framework or chassis also militates against the easy introduction of variants of a standard appliance design.

According to the present invention, a cooking appliance comprises an oven chamber structure formed from panels and having a front opening giving access to the interior of the oven, the oven structure being mounted directly on an apertured front panel member and directly on outer side panel members and being supported thereby, the aperture being aligned with the opening.

The cooking appliance may further comprise an additional cooking chamber structure formed from panels and having a front opening giving access to the interior of the additional structure, and in which the front panel member has an additional opening, the additional chamber structure being mounted directly on the front panel member and the outer side panels and being supported thereby, the additional aperture being aligned with the front opening of the additional chamber.

The outer side panel members may have projections that co-act with apertures in the oven chamber structure or oven chamber structure and additional chamber structure to support the latter.

The projections may be integral with a channel-shaped extension of the outer side panel members.

The oven chamber structure and oven chamber structure and additional chamber structure may be contoured to mate with the extensions and may have a back wall or back walls contoured to mate with the extensions.

The panels may be of sheet-like form.

Some of the panels may have connectors that locate in apertures in other panels to secure the panels together and the connectors may be integral with the panels.

The connectors may be tags that are adapted to be distorted for the purpose of securing panels together.

Alternatively, the connectors and/or the apertures may be resilient at least in part, that part being distorted during location of a connector in an aperture and restoring to its original form thereafter to retain the connector in position.

The front opening of the oven chamber structure may have a peripheral flange by means of which the structure is located on the front panel member.

Similarly, when an additional chamber is incorporated, its opening may have peripheral flanges by which it is located on the front panel member.

The aperture or both the apertures may be located in a recessed portion of the front panel member, the recessed portion being sized to accommodate an oven door or an oven door and a chamber/oven door.

The peripheral flanges may be contoured to receive and support a door seal.

The outer side panels may also support a hob structure and may include extensions between which the hob structure is mounted and to which it is secured.

The hob structure may be secured by means of co-operating holes and projections.

The panels and/or panel members or some of them may be of sheet metal or they may be of a high strength inorganic material based on hydraulic cement.

Embodiments of the invention and methods of manufacturing these will now be described in greater detail with reference to the accom-.

panying drawings of which: Figure 1 shows oven panels in end elevation, Figure 2 is a perspective view of the oven panels shown in Fig. 1, Figure 3 is a perspective view on an enlarged scale of a joint between adjacent panels, Figure 4 is a perspective view of a part completed oven structure, Figure 5 is a perspective view of the structure of Fig. 4 at a later stage of assembly, Figure 6 is a perspective view of a grill chamber/second oven structure, Figure 7 is a perspective view partly in exploded form of a cooker at one assembly stage, Figure 8 is a side elevation of the parts of the cooker shown in Fig. 7, Figure 9 is a perspective view of part of the cooker at a later assembly stage, Figure 10 is a perspective view of part of the cooker, Figure ii is an exploded view of the cooker at a later assembly stage, Figure 12 is a perspective view in exploded form of upper part only of the cooker, Figure 12A is a scrap view on an enlarged scale, Figure 13 is an end view of another form of oven structure in exploded form, Figures 14, 14A, 15 and 16 are scrap views of parts of the structure of Fig. 13, Figure 17 is an end view of the structure of Fig. 13 at a later assembly stage, Figures 18 and 18A are, respectively, a front elevation and section along line XVIII XVIII of Fig. 18 of an oven back panel, Figure 19 is an end view in exploded form of a grill chamber, Figures 20 and 20A are respectively a front elevation and section along line XX-XX of Fig. 20 of a grill chamber back panel, Figure 2 1 is a schematic side view of the oven structure of Fig. 13 and part of an outer front panel, Figures 21A and 21B are scrap views on an enlarged scale of details of Fig. 21, Figure 22 is a schematic section on horizontal plane of the oven structure of Fig. 13 and part of an outer front panel and outer side panel, Figures 22A and 22B are scrap views on an enlarged scale of detail of Fig. 22, Figure 23 is a vertical section of a cooking appliance embodying the invention, Figure 24 is a vertical section of another cooking appliance embodying the invention.

The cooking appliance now to be described is a domestic cooker and is built up from sheet metal panels. As will become clear below, the basic construction is readily capable of adaptation to produce different variants of the basic design.

Figs. 1 and 2 show the method of constructing the cooker oven. The oven includes a floor panel 1 of sheet metal and sheet metal side panels 2, 3.

The floor panel 1 has a peripheral, downwardly-extending flange 4, the lower parts of the flange along the sides of the panel 1 being out-turned as shown at 5.

The side panels 2, 3 have pressed-out shelf support ledges 6 and spaced guides 7. Each side panel also has deep front and back flanges 8, 9 and upper and lower flanges 10, 11 which are less deep than the flanges 8, 9.

Spaced tags 12 are pressed upwardly out of the upper and lower flanges 10, 11.

When the floor and side panels are aligned prior to being secured together, the tags 12 on the lower flanges 11 mate and engage with slots (not shown) in the out-turned parts 5 of the flanges 4 along the sides of the floor panel 1. To secure the floor and side panels together, the tags are twisted to lock over the parts 5 and thereby secure the panels together.

Fig. 3 shows, on a larger scale, detail of the tag and the way in which it is twisted to secure adjacent panels together.

In Fig. 3, tag T is pressed out of flange F, the resultant aperture in the flange being indi cated at A. The tag T is inserted through a mating hole H in the flange of an adjacent panel, and is then twisted to prevent withdrawal of the tag from the hole H and thereby secure the panels together.

Fig. 4 is a perspective view of the oven structure at a later assembly stage. A back panel 13 of sheet metal has been added. The panel 13 has a central area 14 raised with respect to the remainder of the panel and surrounded by a peripheral ledge on which seat the rear flanges 9 of the side panels 2, 3 and that length of the flange 4 round the floor panel 1 that lies along the rear edge of the latter panel.

Formed externally of the ledge and along the vertical sides of the back panel 13 are flanges 1 5 that are cranked rearwardly and outwardly as can be seen in Fig. 7. Additionally, and as shown in Fig. 4, the back panel extends uopwardly and downwardly beyond the side panels 2, 3 as indicated at 16.

The manner in which the back panel 13 is secured in place will be described below.

To complete the oven structure, a roof panel 17 is added, the structure then being as shown in Fig. 5. The panel 17 also of sheet metal has a peripheral flange, the side portions of which have holes in which the tags 12 in the upper flanges 10 of the side panels 2, 3 are engaged and secured in the manner described above.

The roof panel 1 7 has a central recessed area 18 within which is located an inverted wedge shaped depression 19 that projects downwardly into the interior of the oven structure. The purpose of the depression 19 that is pressed from the roof panel is to assist the circulation of heated air within the oven.

The oven structure shown in Figs. 1, 2 and 4 is suitable for an electrically-heated oven, the location and manner of mounting of oven heating elements being described below.

The oven structure shown in Fig. 5 is suitable for a gas heated oven. The floor panel 1 has an opening 20 adjacent its rear wall to permit entry into the oven of products of combustion from an oven burner aligned with the aperture and a mounted upon a support below the floor panel. The floor panel 1 also has a central portion 21 that is recessed slightly with respect to the remainder of the panel and serves to strengthen the latter.

The cooker also includes a grill chamber/second oven structure that is of a construction generally similar to that of the oven structure described above.

The grill chamber structure is shown in perspective view in Fig. 6, It consists of a floor panel 22 of sheet metal, side panels 23, 24 also of sheet metal, and a back panel and roof panel 25, 26 respectively that are also of sheet metal.

The form of the panels that make up the grill chamber structure is generally similar to that of the panels that make up the oven structure and they are secured together in a similar manner. Thus, Fig. 6 shows the side flanges 27 along the front and back of the side panels 23, 24 and the side flanges 28 on the back panel 25. Tags joining the side panel 23 to the floor panel 22 are indicated schematically at 29. The manner in which the back panel 25 is secured in place will be described below.

The grill chamber structure just described may be modified as necessary to accommodate a grill burner which may be of the surface combustor type. Such modifications may include the provision of an aperture or apertures in the roof panel 26 to permit entry into the chamber of air to support combustion and to enable fuel supply connections to be made to the grill burner.

In the case of an electric cooker, the grill chamber/second oven structure may have a grill element as well as heating elements that are brought into operation only when the second oven feature is to be used.

The oven and grill chamber structures are located one above the other in alignment with corresponding openings in a front panel.

Fig. 7 shows the arrangement in perspective form prior to the structures being engaged in the openings of and secured to the front panel. Fig. 8 shows the arrangement in side elevation.

The front panel 30 also of sheet metal has a major rectangular opening 31 giving access to the interior of the oven structure and a minor rectangular opening 32 giving access to the interior of the grill chamber structure. The openings 31 and 32 are bounded by flanges 33 and 34 respectively that extend from the front panel 30 into the mouths of the oven and grill chamber structures respectively.

The apertures 31, 32 are themselves located in an area 35 of the front panel 30 that is recessed with respect to the remainder of the panel. The recessed area permits the use of oven and grill chamber doors that can be flush mounted with respect to the remainder of the front panel.

Above the upper aperture 32, the front panel 31 has a flat area 36 that provides a control panel for the cooker. Area 36 is apertured as at 37 to allow the passage through the panel of the spindles of control knobs and/or switches described below. The area 36 also carries information relating to the operation of the knobs and/or switches.

Round the periphery of the front panel 30 is a deep flange 38 which, when the various parts are assembled, locates against the corresponding flanges on outer side panels.

Each outer side panel is of sheet metal with a flange 41 along its front, rear and bottom edges. The upper edge of each panel is extended as at 42, the front and rear edges of the extension being inclined as indicated at 43 and, together with the upper edge having a flange 44 that, in effect, forms a continuation of the flange 41. The edges 43 commence at locations spaced by a short distance from the front and back edges of the outer side panel.

The flanges 41 along the rear edges of the outer side panels are inturned as indicated at 45 to enable them to clamp the flanges 15 and 28 on the oven and grill chamber structures respectively.

Additionally, the flanges 41 along the rear edges of the side panels 39, 40, have a series of spaced projecting tongues along the lengths of the flanges. Those tongues co-operate with appropriately positioned slots in the flanges 15 and 28 of the grill chamber and oven to locate the rear of those components and also to support them.

Fig. 9 shows one such tongue 65 entered through a slot 66 in a flange which is either that 15 of the oven structure or that 28 of the grill chamber.

The flanges 41 along the front edges of the outer side panels 39, 40 locate against the edges of the flange 38 on the sides of the front panel 30, the flanges 8 on the side panels 2, 3 of the oven structure and those 27 of the side panels 23, 24 of the grill chamber structure abutting the inner surface of the recessed area 35 of the front panel 30.

The front panel 30 is secured to the flanges 41 on the outer side panels 39, 40 by selftapping screws that pass through prepared holes in the flanges. The holes in the front panel member are indicated at 50A in Figs. 7 and 10.

Thus, the screws prevent separation of the side panels 39, 40 from the front panel 30 and separation of the side panels 39, 40 from the rear walls 14 and 25 of the oven and grill chamber respectively.

The front panel will also be provided with holes for the reception of screws that secure door hinges to the panel. Such hinges support an oven door and a grill chamber door. The doors may be of the drop-down kind or they may be hinged about vertical axes on the left or right hand side of the door to give side opening doors. Doors are indicated diagrammatically in Fig. 11 at D1 and D2 but are not shown fixed in position.

Fig. 10 is a perspective view of the cooker after the front panel 30 and outer side panels 39, 40 have been secured in position.

The outer side panels 39, 40 are spaced from the adjacent side wall of the oven and grill chamber thus leaving a gap in which is located thermal insulation placed round the oven and grill chamber structures at an appropriate stage in the construction of the cooker.

In the case of an electrically heated oven, the heating elements are also located in that space.

Located between the upper parts of the outer side panels 39, 40 is a hob assembly shown in exploded schematic form in Fig. 11.

The hob assembly comprises a spillage tray 45 which is configured to receive pan supports 46 which rest upon the spillage tray 45.

Each pan support is associated with a gas burner 47 which seats upon one of the burner bosses 48 in the spillage tray. Secured to the underneath surface of the spillage tray 45 is a member 49 formed to provide, with the spillage tray, gaseous fuel supply passages leading from each of the burner bosses 48 to injectors mounted upon a gas rail (not shown) but which is located behind the part 36 of the front panel 30. Also mounted upon the gas rail are control valves that control the supply of fuel from the gas rail to the fuel supply passages. The operating spindles of the taps extend through the apertures 37 in the area 36 of the front panel and have control knobs secured to their outer ends.

The gas rail is joined at one end to a gas supply line that terminates at the back of the cooker and will be connected on installation to a gas supply point.

The way in which the hob assembly is secured to the upper parts of the outer side panels 39 and 40 is shown in Figs. 12 and 12A which shows only the spillage tray 45 with the burner bosses 48 and the upper parts of the outer side panels 39, 40 and of the front panel 30.

The extensions 42 of the outer side panels 39, 40 have spaced apertures 42A. Those apertures are positioned to mate with dimples 45A pressed in a side flange 45B formed round the periphery of the spillage tray 45.

Fig. 12A is a scrap view through one of the apertures 42A with a dimple 45A located therein.

The aperture 42A and the dimples 45A are sufficient to hold the spillage tray 45 in place.

However, for extra security and safety in electric hobs, the spillage tray 45 has a flap 458 midway of its front edge apertured to receive a fixing screw 45C that passes through a hole in the area 36 as shown of the front panel 30.

An alternative form of cooker oven and a method of assembling the alternative form will now be described in more detail with reference to Figs. 13-22.

As can be seen from Fig. 13, the oven includes two side panels 46, 47, a bottom panel 48 and a top panel 49. The panels are all pressed from sheet metal, during which process the side panels are formed with curved portions along two parallel edges-being the top and bottom edges as indicated at 50, 51, flanges 52, 53 along the top and bottom edges respectively and shelf supports 54. At spaced intervals along the length of the flanges 52, 53, there are formed tongues 55 seen in more detail in Figs. 14 and 14A.

The tongues are pressed out from the flanges and have a short limb 56 by which they are joined to the flange and a horizontal limb 57.

The tongues have raised areas 58, and the limbs 57 are of generally concave form as indicated at 59.

During the pressing process, the top and bottom panels 49 and 48 are also formed with curved edge portions 60 along two parallel sides, flanges 61 being formed at the ends of the edge portions 60. Fig. 14 shows a front lip 49A on the top panel 49. At a suitable point in the forming process, the lip 49A is turned upwardly (as seen in Fig. 14) to form a flange 49B. Panel 48 has a similar flange along its front edge and both panels 48 and 49 have similar flanges along their rear edges.

A similar flange is formed along the front edge of the bottom panel 49.

It should be noted that the side panels 46 and 47 also have front lips of which only one 47A on flange 47 is shown in Fig. 14. The lips on the side panels are left in the orientation shown in Fig. 17 and are not upturned in the manner of lips 49A. Central raised areas 62, 63 are also pressed into these components.

Along the length of each of the flanges 61 and at locations corresponding with those of the tongues 55 is a series of spaced slots 62.

One such slot is shown in Fig. 14. The slots 62 are formed in a slightly raised elongate area 62A of the flanges and it will be observed from Fig. 14 that the slot 62 does not extend along the complete length of the raised area 62A, there being a closed position 62B at one end of the raised area.

The flanges are so orientated with respect to the general surface of the panels that two adjacent panels are assembled by inserting the tongues 55 of one flange through the corresponding slots 62 of the other flange and then adjusting the positions of the panels so that the tongues are at the forward end of the slots as shown in Fig. 14.

Assembly is effected by a process illustrated in Figs. 15 and 16. The flanges and edge portions are so orientated that, on passing the tongues 55 on one side panel-panel 47 in Fig. 15-into the slots 62 in top panel 49 until the flanges abut, the curved edge portions 50 and 60 do not lie precisely in positions which permit the side and top panel to lie in planes substantially at right angles.

There is a discrepancy of about 10" as indicated in Fig. 15. A similar discrepancy arises when the bottom panel 48 is fixed to the side panel 47. However, to secure the remaining side panel in position, the free ends of the top and bottom panels must be pressed towards each other in the direction of the arrow in Fig. 16 before the tongues on the remaining side panel can be engaged in the slots on the bottom panel.

After assembly, there is thus a degree of tension in the curved edge portions and this assists in maintaining the rigidity of the oven structure.

As described above, to insert a tongue into a slot, it is necessary to align the limb 57 accurately with the slot and then force the former into the latter. The height of the area 58 slightly exceeds the width of the slot 62.

Withdrawal of the tongue from its slot is prevented by the raised portion 58 and by the overlap of one end of the horizontal limb 57 and the slot produced as the panels are moved slightly to align their edges.

The assembled panels of the oven are shown in Fig. 17 and it will be observed that the ends of the oven are of substantially rectangular form.

The assembly of Fig. 17 has a back panel 63 is seen in Figs. 18 and 18A. The back panel 63, also of sheet metal, has a central raised area 64 which locates in the open rear end of the oven, and channel-shaped extensions 65 along its vertical and horizontal (as seen in Fig. 18) sides. A central depression 64A imparts a degree of strength and enables the back panel to withstand thermal cycling without flexing. A series of spaced slots 66 are formed in one wall of the extensions 65 along the vertical edges and those slots are also shown in Fig. 18 and referenced 66. The extensions 65 also have rectangular apertures 65A midway of their ends. The apertures 65A permit the passage through the extensins 65 of an electric wiring harness when the oven is part of an electric cooker.

The rear edge of the side, top and bottom panels of the oven are cranked to accommodate the raised area 64 and Fig. 21B shows the configuration of the crank at 4813.

When the cooker includes a grill chamber, this is of a construction similar to that of the oven, as can be seen from Fig. 19. The grill chamber is built up from four panels 69A, 69B, 69C and 69D of a configuration generally similar to that of the oven panels 46, 47, 48 and 49 respectively. The panels 69A-69D are secured together by means of tongues and slots in side flanges in the manner shown in Fig. 14 and described above, the arrangement maintaining the rigidity of the grill chamber structure.

The grill chamber also has a back panel 100 shown in Figs. 20 and 20A. The back panel has a central rectangular depression 102 formed in a central area 101 but is otherwise of the same general configuration as the oven back panel shown in Figs. 18 and 18A. The depression 102 provides a degree of strength to the back panel and enables it to withstand thermal cycling without flexing. Panel 100 has channel-shaped extensions 103 along its vertical sides and those are apertured at 104 and slotted at 105. The aperturs 104 serve the same function as the apertures 65A in the oven back wall.

When used as part of a cooker, the oven, just described with reference to Figs. 13-17, is supported, together with a grill chamber and a hob assembly, by a front panel similar to panel 30 referred to above and by outer side panels similar to outer side panels 39, 40 referred to above.

Figs. 21, 21A, 21B, 22, 22A and 22B illustrate how the front of the oven chamber locates on to the front panel and how the outer side panels mate with and support the rear of the oven chamber.

The front panel 67 is generally similar to front panel 30 described above. Panel 67 has major and minor openings of which Figs. 21 and 22 show only the major opening at 68.

Opening 68 is bounded by a flange 69 which extends round the opening and which fits into a slot 70 in a door seal 71 that extends round the opening. The lips on the oven side panel 46, 47 are positioned against the adjacent face of the seal 71. Fig. 22A shows the positioning of lip 47A of oven side panel 47. It will be observed that the lips are cranked to accommodate part of the seal 71, this being indicated at 47B for lip 47A.

The flanges form from the lips at the front of the upper and lower oven panels 48, 49, i.e. lip 49A shown in Fig. 14, are also positioned against the face of the seal. The lips are also cranked to accommodate part of the seal 7 1 as indicated at 49C.

Figs. 21, 21A, 218, 22, 22A and 22B also illustrate the way in which the back panels are located on and secured to the respective chambers and the manner in which the outer side panels 67A support the chambers.

The raised central area 64 of the back panel 63 locates within tongues along the rear edges of the side panels 46 and 47. One of those tongues is shown at 47C in Fig. 22B which also shows the cranked contour of the tongue at 47D to accommodate the area 64.

The flanges at the rear edges of the upper and lower panels 48, 49 are cranked to accommodate the raised area 64 of the back panel 63. Fig. 218 shows the contour of the flange 48A, the cranked area being referenced 48B.

Each outer side panel 67A is of sheet metal with a peripheral flange along its front, back and bottom edges. As has been explained above, the flanges along the back edges of the side panels are channelled to mate with the extensions 65 of the back panel 63 of the oven and with extensions 103 of the back panel 100 of the grill chamber. In addition, the flange has a series of tongues spaced over that part of its length that mates with the extensions 65 and 103 and these tongues locate in the slots 66 and 105 to support the oven and grill chamber on the outer side panels.

Self-tapping screws are used to secure the front panel to the outer side panels and thus consolidate the entire structure as is explained above. One such screw is shown at 678 in Fig. 22.

The oven described above with reference to Figs. 13-17 may also be used in "built-in" form in addition to the free-standing form shown in Fig. 10.

In built-in form, the oven may be used in conjunction with a grill chamber on its own.

Fig. 23 shows a built-in form comprising the oven 68 located beneath a grill chamber 69 housed in a compartment bounded by upper and lower walls 70, 71 and a rear wall 72.

The oven is gas-fired and Fig. 23 shows an oven burner located in a burner housing 73 beneath the bottom panel 74 of the oven.

The bottom panel 74 is apertured above the burner and the products of combustion leave the oven cavity by way of an aperture in the top oven panel 76.

The grill chamber 69 has a top panel 77 adapted to receive a grill burner 78 and is otherwise of a construction similar to that described above with reference to Fig. 19.

The oven 68 and grill chamber 69 are supported in the cavity by a front outer panel 79 generally similar to panel 30 and by side outer panels similar to panels 67A (not shown) described above. The front panel 79 fits closely against the front edges of the walls bounding the cavity.

In a manner similar to that described above, the front outer panel 79 has a major rectangular opening giving access to the oven cavity and a minor rectangular opening giving access to the grill chamber cavity. Those openings are bounded by flanges (not shown) that fit into the mouths of the oven and grill chamber cavities and are also located in an area of the front panel 79 that is recessed with respect to the remainder of the front of the front panel so enabling oven and grill chamber doors to be flush mounted in the front outer panel.

Above the minor opening, the front panel 79 has a flat area 80 that forms a control panel for the unit. Extending through the control panel are the spindles of the controls for the oven and grill burners. The control panel may also support a timer unit.

Fig. 24 shows a built-in form incorporating an oven only. The oven 81 is gas-fired and is generally similar to oven 68 described above.

Oven 81 is shown supported in a cavity bounded by upper and lower walls 82, 83 and by a rear wall 84. The oven is supported in the cavity by an outer front panel 85 and by outer side panels. Front panel 85 is generally similar to panel 79 but only one rectangular opening which gives access to the cavity of the oven 81. Outer side panels are similar to panel 67A but of a smaller overall height.

Outer front panel 85 has a flat area 86 at its upper end which forms a control panel whose function is similar to that of panel 80 referred to above.

In the embodiment described above with reference to Figs. 23 and 24, the outer side panels not only support the oven and grill chamber or oven but also act as heat shields between the oven-grill chamber structures and adjacent surfaces.

The outer side panels may be slotted or otherwise apertured to facilitate air flow between the panels and the oven-grill chamber structures, and between the panels and adjacent surfaces.

It will be appreciated that the cookers described above are made up using a series of panels easily produced by sheet metal presses. The panels are conveyed to an assembly line where the individual panels are secured together to form first the oven structure, then the grill chamber/second oven structure if required. Those structures are then assembled to the front and outer side panels after which the hob is added if required.

Finally, doors are mounted in the recessed portion of the front panel 30.

It will be understood that the sheet metal panels prior to arrival at the assembly line have been subjected to the usual surface treatment processes including the application of vitreous enamel or paint coatings where applicable. The panels forming the oven and/or grill chamber structures may have "selfclean" coatings on the appropriate surfaces.

Such self-clean or catalytic coatings are well known.

The surface treatment of individual panels avoids many of the problems associated with the surface treatment of structures, for example the latter require large drain holes when surface treatments include dipping techniques. Furthermore, inspection of panels prior to assembly is a relatively easy matter as is the replacement of a damaged panel. It is necessary to replace only the damaged panel and not the entire structure of which the panel forms a part.

Panel assembly is readily adapted to the use of robots.

The principles of construction described above are applicable to other more elaborate forms of cooker, merely by using panels of appropriate configuration.

The oven structure may be that of a microwave oven in which case the junctions between panels may need to be made proof against radiation leakage such as for example by the use of a metallic mesh seal and/or a silicone loaded with metallic particles.

For example, the back panel 14 of the oven structure may be such that it supports an oven fan which circulates air within the oven.

By using suitable front panels, the cooker may be of the "slot-in" variety, or the "eye-level" variety, in addition to the "built-in" and "freestanding" embodiments already described.

It is not essential to have separate oven and grill chambers, the latter may be incorporated in the oven chamber. In such a case, the front panel 30 will have only the larger aperture giving access to the interior of the oven structure.

Again, the cooker may be of the electric variety in which case oven heating elements are located and supported externally of the side panels of the oven structure between that structure and the outer side panels. The hob may have electric heating units which may be radiant rings or hot plates or infra-red heaters or a combination of some or all of such alternatives.

The cooker may be of the "mixed" fuel variety. Thus, the oven and grill chambers may be heated by gas burners and the hob may have electric heating units. Other combinations are possible, the hob may have both electric heating units and gas burners.

It is also envisaged that the cooker may be retailed as a kit of parts which the purchaser assembles. Because of the use of panels, the kit can be packaged as a flat pack.thereby reducing storage space and easing transportation.

Although the panels referred to above are of sheet metal construction, it is envisaged that some or all of them could be made from high strength inorganic materials based on hydraulic cement. Suitable materials are those described in European Patent Applications Nos.

80.301909.0 and 81.301228.3. The panels may, where necessary, be secured together using a suitable heat-resistant adhesive.

A hob unit employing those materials is described in U.K. Patent Application No.

85.17785.

Claims (21)

1. A cooking appliance comprising an oven chamber structure formed from panels and having a front opening giving access to the interior of the oven, the oven structure being mounted directly on an apertured front panel member and directly on outer side panel members and being supported thereby, the aperture being aligned with the opening.

2. A cooking appliance as claimed in claim 1 and further comprising an additional cooker chamber structure formed from panels and having a front opening giving access to the interior of the additional structure, and in which the front panel has an additional opening, the additional chamber structure being mounted directly on the front panel member and the outer side panels and being supported thereby, the additional aperture being aligned with the front opening of the additional chamber.

3. A cooking appliance as claimed in claim 1 or 2 in which the outer side panel members have projections that co-act with apertures in the oven chamber structure or oven chamber structure and additional chamber structure to support the latter.

4. A cooking appliance as claimed in claim 3 in which the projections are integral with a channel-shaped extension of the outer side panel members.

5. A cooking appliance as claimed in claim 4 in which the oven chamber structure or oven chamber structure and additional structure is or are contoured to mate with the extensions.

6. A cooking appliance as claimed in claim 5 in which the oven chamber structure or oven chamber structure and additional structure has or have a back wall or back walls contoured to mate with the extensions.

7. A cooking appliance as claimed in any one of the preceding claims in which the panels are of sheet-like form.

8. A cooking appliance as claimed in any one of the preceding claims in which some of the panels have connectors that locate in apertures in other panels to secure the panels together.

9. A cooking appliance as claimed in claim 8 in which the connectors are integral with the respective panels.

10. A cooking appliance as claimed in claim 9 in which the connectors are tags that are adapted to be distorted for the purpose of securing panels together.

11. A cooking appliance as claimed in claim 9 in which the connectors and/or the apertures are resilient at least in part, that part being distorted during location of a connector in an aperture and restoring to its original form thereafter to retain the connector in position.

12. A cooking appliance as claimed in any one of the preceding claims in which the front opening of the oven chamber structure has a peripheral flange by means of which the structure is located on the front panel member.

13. A cooking appliance as claimed in claim 2 or any one of the preceding claims when appended to claim 2 in which the front openings have peripheral flanges by means of which the oven chamber structure and the additional chamber structure located on the front panel member.

14. A cooking appliance as claimed in any one of the preceding claims in which the firstmentioned aperture or the first mentioned aperture and the second aperture is or are located in a recessed portion of the front panel member, the recessed portion being sized to accommodate an oven door or an oven door and a chamber/oven door.

15. A cooking appliance as claimed in claim 14 in which the peripheral flanges are contoured to receive and support a door seal.

16. A cooking appliance as claimed in any one of the preceding claims in which the outer side panels also support a hob structure.

17. A cooking appliance as claimed in claim 16 in which the side panels include extensions between which the hob structure is mounted and to which the latter is secured.

18. A cooking appliance as claimed in claim 17 in which the hob structure is secured by means of co-operating holes and projections.

19. A cooking appliance as claimed in any one of the preceding claims in which some at least of the panels and/or panel member are of sheet metal.

20. A cooking appliance as claimed in any one of claims 1-18 in which some at least of the panels and/or panel members are of a high strength inorganic material based on hydraulic cement.

21. A cooking appliance substantially as herein described with reference to and as illustrated by Figs. 1-12A or Figs. 13-22 or Fig.

23 or 24 of the accompanying drawings.