EP2381176B1

EP2381176B1 - A method for producing oven muffles, an oven muffle and an oven comprising such oven muffle

Info

Publication number: EP2381176B1
Application number: EP10003524.5A
Authority: EP
Inventors: Tobias Weber; Willi Kranz; Richard Wiesinger; Michael Wittmann; Bernd Heisswolf
Original assignee: Electrolux Home Products Corp NV
Current assignee: Electrolux Home Products Corp NV
Priority date: 2010-03-31
Filing date: 2010-03-31
Publication date: 2019-01-09
Anticipated expiration: 2030-03-31
Also published as: EP2381176A1; WO2011120674A1

Description

The present invention relates to a method for producing oven muffles, an oven muffle and an oven comprising such oven muffle.
Ovens and particularly ovens for domestic use usually are designed to have standard dimensions so that the oven can be used in a kitchenette or built-in kitchen, in which the individual components such as cabinets and devices usually are provided with certain dimensions. Thus, most ovens for domestic use are designed to have an overall width of 60 cm, wherein some manufacturers also offer ovens with a width of 90cm.
It is an objection of the present invention to provide for a further standardization in the manufacturing of such ovens.
In accordance with the present invention this object is solved by a method for producing oven muffles, wherein a muffle door, a muffle top wall, two opposing muffle sidewalls and a muffle rear wall is provided, wherein said muffle sidewalls are provided with means for supporting food preparation trays at a plurality of discrete heights by alternatively integrally forming a plurality of tracks in the muffle sidewalls, or by providing for each muffle sidewall a tray rack comprising a plurality of tracks and providing means for attaching said racks to said muffle sidewalls, and wherein said muffle rear wall is connected to the muffle floor, the muffle top wall and the muffle sidewalls. In accordance with the present invention in such method a dimensioning and shaping is selected for the components of the oven muffle such that the clear width for insertion of trays at the tray support means of opposing muffle sidewalls is independent of the choice selected for the manner for providing the muffle sidewalls with means for supporting food preparation trays.
In US 3 585 360 A there is disclosed a method for producing oven muffles, comprising:

(a) providing a muffle floor, a muffle top wall, two opposing muffle side walls and a muffle rear wall,
(b) providing the muffle side walls with means for supporting food preparation trays at a plurality of discrete heights, by integrally forming a plurality of tracks (30) in the muffle side walls, and
(c) connecting the muffle rear wall to the muffle floor, the muffle top wall and the muffle side walls.

Furthermore, in WO 2009/107016 A1 there is disclosed a method for producing oven muffles, comprising:

(a) providing a muffle floor, a muffle top wall, two opposing muffle side walls and a muffle rear wall,
(b) providing the muffle side walls with means for supporting food preparation trays at a plurality of discrete heights, by providing for each muffle side wall a tray rack comprising a plurality of tracks and providing means for attaching said racks to the muffle side walls, and
(c) connecting the muffle rear wall to the muffle floor, the muffle top wall and the muffle side walls. Furthermore, DE 197 37 833 A1 also discloses a domestic cooking oven comprising an oven muffle.

In the known oven muffles as there are presently on the market, individual food preparation trays, such as baking sheets, baking trays, pans or racks, had to be provided for each oven model, and even for oven of the same model, which only differ by the type of tray support means. This results from the fact that the oven muffles for a certain type of oven are designed to have certain outer dimensions and hence to have a given width. In an oven muffle, wherein the tracks for supporting food preparation trays are integrally formed in the muffle sidewall, the entire width of the oven muffle is available for insertion of trays. In contrast thereto, in an oven wherein the trays are supported by a tray rack, there always is less space available for insertion of trays, because commonly used racks always have some vertical fixture which connects the individual tracks so as to avoid the need for having to provide for fixtures for every single track to the muffle sidewall. However, such vertical fixture necessarily limits the clear width for insertion of trays, because the trays during insertion at the tracks have to pass the vertical fixture. For this reason, manufacturers of ovens had to provide for each oven model all the various food preparation trays, such as baking sheets, baking trays, pans or racks, in two different widths, i.e. in a smaller width for ovens with tray racks, and in slightly wider width for ovens with integral tray racks.
In accordance with the present invention, the components of the oven muffle are designed such that the clear width for insertion of trays at the tray support means of opposing muffle sidewalls is independent of the type of tray support means. Although in oven muffles of the present invention, in which the means for supporting food preparation trays are provided by integrally forming a plurality of tracks in the muffle sidewalls, the oven muffle generally thus will have a slightly smaller width than in conventional ovens, the concept suggested herein provides for substantial cost savings, because one and the same food preparation tray can be used independently from the type of tray support means. While thus at the side of the manufacturer capital costs for manufacturing tools of such oven inserts as well as costs for manufacturing, storing and distributing such trays are saved, the concept suggested herein also is of advantage for the consumers, because the number of different widths at which a certain tray is available is reduced.
The above object is correspondingly solved by an oven muffle as it is defined in claim 9 as well as by an oven comprising such muffle as it is defined in claim 10.
Preferred embodiments of the present invention are defined in the dependent claims.
In particular, when integrally forming tracks in the muffle sidewalls, such tracks preferably are formed by deep-drawing a plurality of elongated plateaus, which are raised towards the interior of the oven muffle, wherein the clearance between adjacent plateaus defines the tracks. In order to provide for the same clear width for insertion of trays in such an oven muffle as compared to an oven muffle in which a tray rack is provided, at least one additional plateau can be formed in the muffle sidewall, the height of which plateau corresponds to the extent by which the tray rack narrows the clear width between opposing muffle sidewalls. By providing such a plateau in the muffle sidewall, the overall appearance of the muffle sidewall is similar as in known oven muffles, that is, for the general design for forming the tracks the former designs still can be applied.
In providing oven muffles for ovens which differ only by the type of tray support means, i.e. for oven muffles of product variants of one and the same oven, preferably the same muffle floor, the same muffle top wall and the same muffle rear wall are used. In this manner, the manufacturing costs for the oven muffles can be kept at a minimum, because also for producing ofen muffles comprising different types of tray support means only one type of muffle floor, one type of muffle top wall and one type of muffle rear wall has to be produced.
In an oven muffle in which a plurality of tracks is integrally formed in the muffle sidewalls, the clear width of such oven muffle generally could be adapted to that of a corresponding oven muffle comprising a tray rack, by providing for correspondingly higher plateaus between the individual tracks. Instead of providing for individual higher plateaus, it is preferred to first provide for a single additional plateau in the muffle sidewall, in which additional plateau then a plurality of tracks is formed by integrally forming a plurality of plateaus, similarly as has been done in the prior art muffles. Providing for a single plateau on the one hand minimizes the number of additional bends or impressions that are to be formed into the oven muffle side wall, which thus improves the cleanability of the oven muffle, and on the other hand avoids a larger local deformation of the material during forming.
If the tray rack is made of metal bars, said additional plateau provided by integrally forming a plurality of tracks in the muffle sidewall preferably has a height which corresponds to the diameter of the round stock used for the tray rack. Thus, the additional plateau compensates the restriction in the clear width for insertion of tray as it caused by the tray rack comprising sections where a tray which is inserted into the oven muffle has to pass any bars which rest against the muffle sidewall, such as a vertical bar which connects the bars forming the track.
If for supporting food preparation trays the muffle sidewalls are provided with tray racks, preferably means are provided for removably attaching the racks to the muffle sidewalls, so that the racks can be taken out of the oven muffle for cleaning purposes. In order to provide for means for removably attaching the racks to the muffle sidewalls, the racks can be provided with means to hook the rack into the muffle sidewall.
To this end openings can be provided in the muffle sidewall, where the rack can be hooked in by means of bar sections which project from the tray rack towards the muffle sidewall.
Preferred embodiments of the invention are described below by reference to the drawings, in which:

FIG. 1: is a perspective view of an oven muffle made in accordance with the present invention, wherein a tray rack is provided at the muffle sidewalls for supporting trays;
FIG. 2: is perspective view of an oven muffle made in accordance with the present invention, wherein a plurality of tracks in integrally formed in the muffle sidewalls;
FIG. 3: is a cross-sectional view of the muffle of FIG. 1;
FIG. 4: is a cross-sectional view of the muffle of FIG. 2; and
FIG. 5: is a sectional view of a conventional oven muffle.

Oven muffle 10 shown in FIG. 1 comprises a muffle floor 12, a muffle top wall 14, two opposing muffle sidewalls 16 and a muffle rear wall 18, which are arranged to form a muffle cavity which is open at its front side where in the fully assembled oven an oven door is located. Muffle rear wall 18 is connected to muffle floor 12, muffle top wall 14 and muffle sidewalls 16, for example, by welding.
Oven muffle 10 is formed of sheet metal which preferably is formed by deep drawing. At least the interior surfaces of the oven muffle are provided with a heat- and corrosion-resistive coating, such as an enamel layer, which provides a hard protective surface layer which further facilitates cleaning of the oven muffle. In the embodiment shown in FIG. 1, although muffle sidewall 16 has a centrally located shallow depression 70, muffle sidewall 16 is substantially flat. For supporting trays, muffle sidewall 16 is provided with a tray rack 20 which comprises five tracks where a food preparation tray can be inserted into the oven muffle. Rack 20 is made of metal bars such as stainless steel or the like and comprises two vertical bars 22 and 24 and for each tray position two horizontal bars 26 between which the lateral edge of a tray can be held.
In order to attach tray rack 20 at muffle sidewall 16, tray rack 20 is provided with four projections, which in the embodiment shown in FIG. 1 are provided at the upper horizontal bar 42 of the central tray rack as well as at the two ends of the rear vertical bar 24. For illustrative purposes, in FIG. 1 the projection and the upper end of vertical bar 24 has been designated by reference sign 28. Muffle sidewall 16 is provided with respective openings which accommodate the projections of tray rack 20 when mounted to the muffle sidewall. Thus, for example, the projection at the front end of the upper horizontal bar 42 of the central track is accommodated within an opening 30 which is provided near the front edge of muffle sidewall 16.
FIG. 2 shows an embodiment of an oven muffle, in which muffle sidewall 32 is provided with a plurality of tracks, which are integrally formed in muffle sidewall 32, for example by deep drawing. Tracks 34 are provided within a plateau 36, which extends over the majority of muffle sidewall 32 and which has been formed by providing, preferably by deep-drawing, for a stepped bend 38 which extends about the perimeter of muffle sidewall 32.
FIG. 3 shows a cross-section of the oven muffle shown in FIG. 1. As shown in FIG. 3, when tray rack 20 is attached to muffle sidewall 16, vertical bar 22 of tray rack 20 rests against the inner side of muffle sidewall 16, wherein a projection 40 which for the example shown in FIG. 3 is an extension of the upper horizontal bar 42 of the central tray rack, is inserted through an opening 30 provided in muffle sidewall 16. As is best seen in FIG. 3, tray rack 20 narrows the clear width for insertion of trays between the opposing muffle sidewalls by a distance 44 which in the embodiment shown in FIGS. 1 and 3 corresponds to the diameter of the round material of which the tray rack 20 is made.
FIG. 5 is a cross-sectional view of a conventional oven muffle in which a plurality of tracks 46 is formed in a muffle sidewall 48. Tracks 46 are formed by deep drawing a plurality of plateaus 50, which are raised towards the interior of the oven muffle, wherein the clearance between adjacent plateaus 50 defines the tracks 46. In such a conventional oven muffle the clear width for insertion of trays corresponds to the width of the oven muffle in regions where no plateaus 50 are provided, such as in the regions above and below the tray support region.
By comparison of the sectional view of FIGS. 3 and 5 it will be readily understood that in such a conventional oven muffle as it is shown in FIG. 5, when all other components of the muffle such as muffle floor, muffle top wall and muffle rear wall are identical to a similar oven muffle in which the tracks are supported by a tray rack, such as it is shown in FIG. 3, different trays were required for the oven muffle of FIG. 5 as compared to as is used in the oven muffle of FIG. 3. In particular, the trays used in an oven muffle as shown in FIG. 3 had to have a smaller width than those used in the oven muffle shown in FIG. 5 and in particular had to be narrower by twice the distance 44.
FIG. 4 is a cross-sectional view of oven muffle 52 shown in FIG. 2. In order to be able to use in oven muffle 52 the same trays as they are used in the oven muffle of FIG. 3, in oven muffle 52 the central region of muffle sidewall 32 is similar to that of muffle 48 shown in FIG. 5. Thus, oven muffle 52 comprises a plurality of tracks 54 which are formed by providing a plurality of plateaus 56. However, in contrast to the conventional muffle shown in FIG. 5, in the embodiment of the invention shown in FIG. 4 a double bend 38 is formed about the tray support region so as to form plateau 36, in which then plateaus 56 are formed so as to provide tracks 54. In order to provide in muffle 52 for the same clear width for insertion of trays as in muffle 10, the height 58 of plateau 36 corresponds to the distance 44 by which tray rack 20 narrows the clear width for insertion of trays.
While FIG. 2 shows an embodiment wherein the muffle floor 60 and the muffle rear wall 62 have a different design then the respective elements 12 and 18 of the embodiment shown in FIG. 1, it should be noted that since the dimensions of muffle sidewall 52 of the FIG. 2 embodiment are identical to those of muffle sidewall 16, the same muffle floor, the same muffle top wall and the same muffle rear walls can be used for providing both the flat cavity design shown in FIG. 1 and the molded cavity design shown in FIG. 2. In this manner, substantial savings in manufacturing costs can be achieved.

Claims

A method for producing oven muffles (10; 52), comprising:
(a) providing a muffle floor (12; 60), a muffle top wall (14), two opposing muffle side walls (16; 32) and a muffle rear wall (18; 62),

(b) providing said muffle side walls (16; 32) with means for supporting food preparation trays at a plurality of discrete heights, by alternatively
(i) integrally forming a plurality of tracks (34; 54) in the muffle side walls (32), or

(ii) providing for each muffle side wall (16) a tray rack (20) comprising a plurality of tracks and providing means (28, 30, 40) for attaching said racks to said muffle side walls; and

(c) connecting said muffle rear wall (18; 62) to said muffle floor (12; 60), said muffle top wall (14) and said muffle side walls (16; 32);
in which method a dimensioning and shaping is selected for the components of the oven muffle (10; 52) such that the clear width for insertion of trays at the tray support means of opposing muffle side walls (16; 32) is independent of the choice selected in step (b), in order to provide for the same clear width for insertion of trays into said oven muffle as compared to an oven muffle in which a tray rack (20) is provided,
characterized in that
said tray racks (20) provided in step (b) (ii) are made of metal bars, and wherein at least one additional plateau (36) is formed in the muffle side wall (32) in step (b) (i), wherein said plateau (36) has a height (58) which corresponds to the diameter of said metal bars.
The method of claim 1, wherein in step (b) (i) said tracks (34; 54) are formed by deep-drawing a plurality of elongate plateaus (56) which are raised towards the interior of the oven muffle (10; 52), wherein the clearance between adjacent plateaus defines the tracks.
The method of claim 2, wherein in step (b) (i) the at least one additional plateau (36) is formed in the muffle side wall (32), the height (58) of which plateau (36) corresponds to the extent (44) by which a tray rack (20) narrows the clear width between opposing muffle side walls (16) .
The method of claim 2, wherein the same muffle floor (12; 60), the same muffle top wall (14) and the same muffle rear wall (18, 62) are used for producing oven muffles comprising either type of tray support means.
The method of claim 3 or 4, wherein a single plateau (36) is formed in the muffle side wall (32), in which plateau said plurality of tracks (34; 54) is formed.
The method of any one of the preceding claims, wherein step (b)(ii) comprises providing means (28, 30, 40) for removably attaching said racks (20) to said muffle side walls (16).
The method of claim 1, wherein for producing an oven muffle (52) in which a plurality of tracks (34; 54) is integrally formed in the muffle side walls (32), a muffle floor (12), a muffle top wall (14) and a muffle rear wall (18) is used, which have a smaller width than a muffle floor, a muffle top wall and a muffle rear wall which are used for producing an oven muffle provided with tray racks (34; 54).
An oven muffle (10; 52) that is obtained according to the method of one or more of claims 1 to 7.
An oven, comprising:
(a) an oven muffle (10; 52) as defined in claim 8; and

(b) at least one food preparation tray, wherein the food preparation tray has a single standard width irrespective of the type of tray support means.
The oven of claim 9, wherein said food preparation tray comprises a baking sheet, a baking tray, a pan or a rack.