GB2329467A - Cooking Oven - Google Patents

Abstract

A cooking oven with a cooking compartment 1, heat insulation 5 and an outer casing which comprises a U-shaped shell 6 and a top cover 8. The cover 8 comprises a tray 40 and a profile member 45. The profile member 45 has apertures 52 for the intake of air for cooling purposes.

Description

IMPROVEMENTS TO DOMESTIC COOKING OVENS OF BUILT-IN TYPE The present invention relates to domestic cooking ovens for being built into a space in a kitchen unit. The terms used herein 'cooking ovens of built-in type' also includes so-called 'oven units;', on the control panel of which are also disposed the devices for regulating the electrical and/or gas heating elements of a cooking hob disposed thereabove.

Ovens of built-in type are widespread, which are structurally typified by the provision of the following: - at least one cooking compartment (referred to as a muffle), generally of enamelled iron plate, which contains various functional components in such a way that their terminal portions project form the walls thereof, for example the female terminal portion of the meat probe, - a door for closing the front mouth opening of the muffle, - a heat insulation which encloses the muffle, - a control panel, - a structural support frame structure (chassis), and - an outer protective casing formed by a plurality of metal parts, generally cut and bent panels of steel sheet.

Another structural configuration is also known in which the outer casing is at least partially produced with drawn or dished sheet in such a way as, in the absence of the above-mentioned frame structure, to provide not only a protective function but also a structural support function for the oven by virtue of the enhanced mechanical strength thereof.

The parts of the outer casing are in any case shaped and joined together in such a way as to provide the flow paths for the air which, by virtue also of the possible use of at least one tangential motor-driven fan, ensures cooling of the oven.

Both the above-indicated structural configurations suffer from the following inadequacies: - the parts which make up the outer casing are relatively numerous and therefore production management is complicated and involves high cost levels; - in the event of damage, operations involving technical assistance in relation to functional components having the terminal portions projecting to the exterior of the muffle and protected by the outer casing are complicated and inevitably of long duration. It is necessary firstly to withdraw the oven from the space in the kitchen unit, then detach at least one wall of the outer casing, effect the necessary repair and finally re-fit the previously detached wall and re-insert the oven into the kitchen unit; and - manually moving an oven without packing is difficult and generally impractical especially in the case of particularly heavy models, for example those combined with a microwave.

Therefore the aims of the present invention are as follows: a) rationalise the process for the production of ovens of built-in type with a reduction in the number of parts which form the casing thereof; b) facilitate technical assistance operations; c) optimise cooling of the ovens without increasing the power of the tangential motor-driven fan or increasing the insulation of the muffle; d) reduce the volume and weight of the transportation packings; e) making manual movement without packing easier, to begin with insertion of the ovens in the appropriate spaces in kitchen units.

According to the present invention there is provided a domestic cooking oven of built-in type having at least one cooking compartment with heat insulation on five sides, an outer casing of sheet material of which the bottom wall and the lateral walls are produced in one piece in the form of a U-shaped shell and are removably joined to at least one top cover wall and to a perforated back, wherein said top cover consists substantially of a tray and a profile member which rises from the bottom of the tray and is of a length equal to the distance between the lateral edges of the tray.

To permit the present invention to be better understood a preferred embodiment will now be described with reference to the accompanying drawings in which: Figure 1 is an exploded view showing the more relevant structural parts of a domestic cooking oven of built-in type according to the invention; Figure 2 is a perspective view of the top cover of the outer casing of the oven; Figure 3 is a partial vertical section, at the end of assembly of the oven, in the vertical central plane thereof, to show the upper and rear parts thereof; Figure 4 is a partial section of just the outer casing taken along line X-X in Figure 3; Figure 5 is a partial perspective view of the outer casing to show the fixing of the spacer runners; Figure 6 is a vertical section of the lower zone of the outer casing taken along the vertical central plane to show how it is fixed to the base of the oven transportation packing; Figure 7 is a side view of the zone of the outer casing, which comprises a cover portion and is defined by a dash-dotted circle in Figure 1; and Figures 8 to 11 show the sequence of the operations required for technical assistance in relation to a functional component of the oven protected by the cover portion in Figure 6.

As illustrated in Figure 1 the basic structural parts of a built-in oven according to the invention are as follows: an enamelled cooking compartment (muffle) 1 of substantially parallelepipedic shape with a pair of lugs 2, a rear load-bearing transverse portion 3, and enamelled front flange 4, a U-shaped shell 6, a perforated back 7, a top cover 8 and a panel 9 for the controls of the oven (not shown) which are protected by a plate 10. The muffle 1 is enclosed on five sides by a thermal insulation 5 made of fibreglass which remains secured in position by the transverse portion 3 after the latter in per se known manner is secured by screws or other fixing elements (not shown) to the lugs 2 and thus to the compartment 1.

The shell 6, the back 7, the top cover 8 and the plate 9 which are all parts made from iron sheet form the socalled outer casing of the oven. While the back 7 and the plate 10 are of conventional design so that a more detailed description thereof is not necessary, the other two parts of the outer casing will be described herein in greater detail since a leading feature of the present invention resides therein.

The U-shaped shell 6 which constitutes the top surface 61 and the lateral surfaces 62 and 63 of the outer casing of the oven is produced by cutting and drawing a single sheet of plate metal. The lateral surfaces 62 and 63 are drawn or dished in the proximity of their upper horizontal edges 64 and 65 which are in turn bent in an Lshape and in their central zone 66 and 67 in such a way as to impart substantial structural strength to the oven. Along the upper edges 64 and 65 the lateral surfaces 62 and 63 are provided with openings 68 and 69 which are set inwardly with their edges, see Figures 1 and 4.

The top cover 8 substantially consists of a tray or dish 40 of substantially rectangular shape which constitutes the front portion thereof and a profile member 45 in the form of an inverted U which rises from the bottom 41 and constitutes the rear portion of the top cover 8.

The tray 40 which has a flat bottom 41 is provided with a front edge 42 and two lateral edges 43 and 44 which are all bent in the shape of an inverted L. In oppositely disposed positions the lateral edges 43 and 44 have elongate openings 49 and 50 which are set outwardly with their edges, see Figure 2. The profile member 45 which extends above a tangential motor-driven fan 55 - see Figure 3 - is of a length equal to the distance between the lateral edges 42 and 43 of the tray 40. It is defined by a front step 47 which serves to hold its horizontal surface 46 raised from the bottom 41 of the tray 40, and a rear edge 48 which is directed rearwardly and bent in the shape of a L. The horizontal surface 46 of the profile member 45 is stiffened over substantially the entire length thereof by a rib 51 produced by stamping.

As can be clearly seen from Figures 2 and 3 the step 47 which is of smaller height than the edges 42, 43 and 44 of the tray 40 is provided with a plurality of holes 52 through which the air, after having cooled the walls of the oven, are drawn by a tangential fan 55 to be expelled into the ambient atmosphere by way of a conduit 54 which emerges in known manner in the front region of the oven.

To produce the outer casing of the oven the top cover 8 is fitted on top of the U-shaped shell 6 in such a way that, for example by means of screws (not shown), the lateral edges 43 and 44 of the tray 40 can be fixed to the above-mentioned upper horizontal edges 64 and 65, the front edge 42 to the plate 10 for protecting the controls of the oven, and the rear bent edge 48 of the profile member 45 to the back 7. For final assembly, the openings 49, 68 50 and 69 are disposed in adjacent relationship, as shown in Figure 4, so as to give rise, on the right-hand and left-hand surfaces of the outer casing, to two robust and absolutely secure gripping configurations insofar as the edges are taken off and are not sharp, for manual movement of the oven. It is moreover always possible in per se known manner to insert protective caps made of plastics material into said two pairs of openings.

The construction of the outer casing of the oven as described hereinbefore enjoys the following advantages: - the presence of the holes 52 on the vertical step 47 of the profile member 45 optimises the efficiency of suction effect of the tangential fan 55; - the fact that the horizontal surface 46 of the profile member 45 is raised with respect of the bottom 41 of the tray 40 of the top cover 8 prevents the occurrence of unpleasant electromagnetic noise due to the motor (not shown) of the tangential fan 55; and - the rib 51 on the horizontal surface 46 of the profile member 45, together with the drawn upper edges 64 and 65 of the U-shaped shell 6 imparts to the outer casing a high level of mechanical resistance to the lateral thrust forces of the arms of the lift trucks with which the ovens are moved, for example in distribution warehouses. In that way, it is possible to reduce the mass of the transportation packing, with resulting advantages in terms of environmental protection.

A second feature of the present embodiment resides in the outer casing of the oven. The lowered lateral edges 71 and 72 of the bottom wall 61 of the U-shaped shell 6 are provided with a plurality of seats 73 and 74 for the quickrelease insertion of the tangs 16 and 17 of two spacer runners 14 and 15 made of self-lubricating plastics material, for example nylon, see Figure 5. The runners 15 perform the function of holding the oven upwardly in the space in the kitchen unit and in addition, being easily slidable on the bottom of that space during the operations of inserting and removing the oven, they considerably reduce the amount of exertion required by the person dealing with installation and/or technical assistance.

A third feature of the embodiment lies in the fact that integrally provided in the central zone of the bottom wall 61 of the U-shaped shell 6 are bridge portions 20 capable of being retained by recesses 24 provided on the internal surface of and in a central position on the base 22 of the transportation packing which is made of rigid expanded material and provided with reinforcing ribs 23 and 24, see Figure 6.

That characteristic provides that, besides holding the base 22 of the packing in contact with the casing of the oven during transportation from the manufacturing establishment to the point of installation, it is advantageously possible to use the base 22 of the packing which is made of expanded material in the form of a halfshell portion with stiffening ribs 23 to constitute the platform on which, in the production establishment, assembly of the oven is effected, an operation which can thus be implemented with a high level of production and quality efficiency.

A further feature of the embodiment is aimed at facilitating the operations involving technical assistance on the oven in the event that functional components of the oven which are only accessible from the outside of the cooking compartment 1 have to be repaired or possibly replaced. By way of example the following description refers to the case of the female terminal portion of the meat probe which is not shown but which is disposed under the left-hand surface 62 of the U-shaped shell 6 of the outer casing of the oven just behind the mouth opening of the compartment 1, see Figure 1.

The invention provides for producing, by means of cutting of the metal sheet with which the entire shell 6 is produced (including the above-mentioned left-hand surface 62), a cover portion 25 of substantially square section which is dished at the centre - see Figure 1 - which, on the finished oven, is in a position exactly over the terminal portion of the meat probe and thus protects it.

The detail features of the cover portion are shown on an enlarged scale in Figure 7.

The cutting line 26 which defines the perimeter of the cover portion has along the upper side 27 two pairs of transverse enlargements 28 and 29, 30 and 31 which define a pair of brace or straps 32 and 33 of V-shaped configuration.

By means of the portions 32 and 33, the cover portion 25 remains locally joined to the above-mentioned left-hand surface 62 of the U-shaped shell 6. On the lower side 35 opposite to the first side, the cutting line 26 has two further transverse enlargements 36 and 37 which, together with an elongate hole 38, define two tongue portions 39 and 40. In that way the tongue portions 39 and 40 constitute a further localised join for the cover portion 25 to the lateral wall 62 and have predetermined fracture points in the metal sheet. Outside the perimeter of the cover portion 25 the lateral wall 62 has a circular hole 81 which is disposed in the immediate vicinity of the above-mentioned elongate hole 38 but is of a reduced diameter.

The operations which are performed by the technical assistance service personnel in the event of damage to the above-mentioned female terminal portion of the meat probe which is under the cover portion 25 will now be described.

First of all it is sufficient for the oven to be only partially withdrawn from the space in the kitchen unit in which it is fitted, in practice to the point at which the entire periphery of the cover portion 25 is accessible. The tip of a screwdriver S is then forced into the two enlargement portions 36 and 37 on the bottom side 35 of the cutting line 26 - see Figure 8 - in such a way as to cut the tongue portions 39 and 40 (predetermined facture points).

The hole 38 is transformed into a recess 43 in the lower (free) edge 42 of the perimeter of the cover portion 25 which nonetheless remains connected to the left-hand surface 62 of the U-shaped shell 6 by means of the portions 32 and 33. At that point the cover portion 25 is opened by pulling it upwardly with a rotary movement in the direction indicated by the arrow in Figure 9 in such a way that it rotates about an imaginary hinge line Z-Z which extends along the first side 27 of the cutting line 26 of the cover portion 25, that is to say along the apexes of the V-shaped configurations of the portions 32 and 33. At that point the cover portion remains open insofar as it is held in that position by the portions 32 and 33 and it is possible to effect the repair operation since an opening 45 remains open in the left-hand surface 62, that opening making the subjacent functional component to be repaired easily accessible, see Figure 9.

Once the repair operation is completed the shaped portions 32 and 33 are flattened and consequently elongated by means of a pair of pliers P - see Figure 10 - and then the cover portion 25 is closed by a rotary movement about the imaginary line Z Z in the opposite direction to that shown in figure 9, see Figure 11. At the end of that second rotary movement the cover portion 25 is disposed displaced a little more downwardly from the initial position due to the effect of the rapid elongation of the portions 32 and 33 in such a way as to close the opening 45. With the cover portion 25 in that new position the recess 43 in the lower edge 42 thereof is disposed adjacent the circular hole 81 in the lateral wall 62 of the U-shaped shell 6. A screw 46 provided with a toothed washer 47 is then tightened with the screwdriver S in the hole 81, passing through the recess 43, in such a way as to press against the tongue portions 39 and 40. That ensures that the cover portion 25 is closed in such a fashion as to conform with the safety standards which prohibit access to voltage-bearing electrical components without the use of tools. At that point the oven is re-inserted into the space in which it is built into the kitchen unit from which, as already stated hereinbefore, it was only partially withdrawn.

Claims (9)

1. A domestic cooking oven of built-in type having at least one cooking compartment with heat insulation on five sides, an outer casing of sheet material of which the bottom wall and the lateral walls are produced in one piece in the form of a U-shaped shell and are removably joined to at least one top cover wall and to a perforated back, wherein said top cover consists substantially of a tray and a profile member which rises from the bottom of the tray and is of a length equal to the distance between the lateral edges of the tray.

2. An oven according to claim 1 and provided with a tangential motor-driven fan for expelling the cooling air by way of a conduit which emerges in the ambient atmosphere at the front zone of the oven, wherein provided on a step which defines at the front the profile member of the top cover is at least one opening for intake of the cooling air from said motor-driven fan and that the horizontal surface of the profile member is integrally provided substantially over its entire length with a stiffening rib means.

3. An oven according to claim 1 or claim 2 wherein provided on the lateral edges of the tray and along the upper edges of the lateral surfaces of the U-shaped shell are respective elongate openings with edges displaced in opposite directions in such a way as to give rise to grip means which serve to implement manual movement of the oven.

4. An oven according to any one of the preceding claims wherein a cover portion is integrally provided on at least one wall of its outer casing, which cover portion is capable of protecting at least one functional component protruding towards the exterior of the cooking cavity, which remains peripherally retained only by way of at least one tongue portion with a predetermined fracture point and, in a zone in opposite relation thereto, by at least one shaped deformable strap.

5. An oven according to claim 4 wherein, by virtue of fracture of said tongue portion, the cover portion can be opened with a rotary movement about a hinge line Z-Z perpendicular to said shaped strap and parallel to the plane of the lateral wall on which the cover portion was provided, to permit access to the subjacent functional component by way of the resulting opening in the lateral wall.

6. An oven according to claim 5 wherein after the cover portion has been opened it can subsequently be closed by means of flattening of said shaped strap which causes downward displacement thereof.

7. An oven according to any one of the preceding claims wherein the lateral edges of the bottom wall of said U-shaped shell are lowered and provided with a plurality of seats for the insertion, preferably in snap-action engagement, of tangs of spacer runners.

8. An oven according to any one of the preceding claims wherein at least one bridge portion is integrally provided on the bottom wall of said U-shaped shell, the bridge portion being capable of being retained by a recess provided in the inside surface of the base of the transportation packing.

9. An oven substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.