MUFFLE FOR CONVECTION OVEN AND OVEN COMPRISING SAID MUFFLE

Description

[0001] This invention concerns convection ovens for cooking food or semi-finished food products, and in particular a muffle with a back having a parabolic profile. In the following, specific reference will be made to an electric convection oven, but it is clear that what is being said can be applied to other types of oven (e.g. gas oven) in which there is a circulation of hot air, possibly also for the heat treatment of non-food products.

[0002] It is well known that the term "muffle" usually indicates the inner chamber of a food oven and the like, suitable for receiving food to be heated or cooked, and there are currently known and widespread muffles consisting of two parts substantially in the shape of a C whose respective concavities are turned towards each other, so as to form a cooking chamber that is closed at the rear by a back and at the front by a door used for the insertion and removal of food.

[0003] The two C-shaped parts are connected to each other and to the back by means of corresponding peripheral flaps, which are coupled through connecting means generally consisting of continuous welding, spot welding or fastening elements such as screws, rivets and the like, possibly with the interposition of appropriate gaskets. Examples of this type of muffle are described in EP 1655544 and ES 2332555, among others.

[0004] Another example of a similar structure is found in EP 2781840 that discloses a muffle comprising a bottom panel, two side panels, a top panel and a back panel that are provided along their edges with fasteners suitable for working together initially by insertion and then by sliding so as to form a pre-assembled structure. The back panel has a central flat zone connected to front edges for fastening to the other panels, the peripheral portion between the central flat zone and the front edges having a uniform curved shape with a section in a plane perpendicular to the back panel that is shaped substantially as a quarter of a circle.

[0005] A drawback of these traditional muffles is that they do not allow a good circulation of hot air flows due to the flat shape of the back that causes pressure losses and unproductive swirls, therefore this shape is not optimal to circulate the air efficiently inside the cooking chamber. As a result, the cooking time and therefore the energy consumption of the oven are rather high, and the cooking is not perfectly uniform because the hot air is not evenly distributed inside the cooking chamber.

[0006] The purpose of this invention is therefore to provide a muffle that is free from said drawbacks. This object is achieved with a muffle equipped with a back having a substantially parabolic profile in the area of air circulation as defined in the independent claim.

[0007] A first important advantage of this muffle is that it considerably improves the circulation of air flows, so that cooking is faster and more uniform, saving time and energy.

[0008] A second notable advantage of this muffle resides in the fact that the greater efficiency of the heating system allows to reduce the use of motors, impellers and resistances that generate and diffuse the hot air, thus obtaining, with the same performance, a considerable economic saving both in the production phase and in the maintenance of the oven.

[0009] Further advantages and characteristics of the muffle according to the present invention will be evident to those skilled in the art from the following detailed description of an embodiment thereof with reference to the annexed drawings, in which:

Fig.1 is a front view of the back of the aforesaid muffle;

Fig.2 is a sectional view of the back along the vertical symmetry plane II-II of Fig.1; and

Fig.3 is a sectional view of the back along the horizontal symmetry plane III-III of Fig.1.

[0010] The attached figures show an exemplifying embodiment of a muffle according to the present invention constituted by two parts substantially in the shape of C whose respective concavities are facing each other, not shown but like those of the above-mentioned prior art, so as to form a cooking chamber that is closed at the rear by a back 1 and at the front by a door (not shown) used for the insertion and the removal of the food. The back 1 is connected to the two C-shaped parts by means of peripheral flaps 2 which are coupled through known connecting means to corresponding flaps present on said two parts.

[0011] The novel aspect of the present muffle lies in the shape of back 1, that is substantially rectangular when seen from the front, in which the part between the outer perimeter and the central circular zone 3, where at least one heating element and a motor that drives a impeller are fixed so as to circulate the hot air inside the oven, is made up of two flat side portions 5 that intersect a horizontal symmetry plane perpendicular to back 1 with lines of intersection having an inclination smaller than 90° with respect to a vertical symmetry plane perpendicular to back 1, two flat top and bottom portions 6 that intersect said vertical symmetry plane with lines of intersection having an inclination smaller than 90° with respect to said horizontal symmetry plane, and four radiused portions with radii 4 connecting said side portions 5 to said top and bottom portions 6. The radiused portions generate lines of intersection that have a substantially parabolic profile when they intersect a plane perpendicular both to back 1 and to any of two diagonal planes passing through the intersection of said symmetry planes and through respective pairs of opposite corners of said rectangular shape, also said diagonal planes being perpendicular to back 1. This profile of back 1 can be obtained by deep drawing from a mould or folding press and subsequent welding of the parts, in any case providing for radii 4 between portions 5 with horizontal inclination and portions 6 with vertical inclination, in order to minimize pressure losses.

[0012] In the example shown, portions 5 generate lines of intersection that have an inclination of 51°±10% with respect to the vertical symmetry plane II-II (Fig.3), while portions 6 generate lines of intersection that have an inclination of 6°±10% with respect to the horizontal symmetry plane III-III (Fig.2). The inclination is in practice the angle formed by the line that in said symmetry planes connects the peripheral edge of back 1, where flaps 2 are formed, to the edge of the central flat part 3 where the active elements of the oven (resistance, motor, impeller) are fixed.

[0013] However, it is clear that these values can be modified according to specific construction requirements depending on the shape and size of the muffle, therefore the value of these angles is purely indicative of a specific embodiment that is susceptible to many variations, in addition to those already mentioned above. For example, the central zone 3 could have a different shape instead of a circular one and could accommodate a variable number of resistances and/or motors and/or impellers. Furthermore, the connection between back 1 and the other parts of the muffle could be made by different means that do not require the presence of flaps 2.

Claims

1. Muffle comprising a plurality of parts connected to form a cooking chamber, said plurality of parts comprising a back (1) provided with a central flat zone (3) capable of accommodating at least a resistance, a motor and an impeller, said back (1) being substantially rectangular in shape when seen from the front and having perpendicular thereto a horizontal symmetry plane, a vertical symmetry plane and two diagonal planes passing through the intersection of said symmetry planes and through respective pairs of opposite corners of said rectangular shape, characterized in that the part between the external perimeter of the back (1) and said central flat zone (3) is made up of two flat side portions (5) whose lines of intersection with said horizontal symmetry plane have an inclination smaller than 90° with respect to said vertical symmetry plane, two flat top and bottom portions (6) whose lines of intersection with the vertical symmetry plane have an inclination smaller than 90° with respect to the horizontal symmetry plane, and four radiused portions with radii (4) connecting said side portions (5) to said top and bottom portions (6), the lines of intersection resulting from the intersection of said four radiused portions with a plane perpendicular both to the back (1) and to any of said two diagonal planes having a substantially parabolic profile.

2. Muffle according to claim 1, characterized in that the lines of intersection of the two flat side portions (5) with the horizontal symmetry plane have an inclination of 51°±10% with respect to the vertical symmetry plane and the lines of intersection of the two flat top and bottom portions (6) with the vertical symmetry plane have an inclination of 6°±10% with respect to the horizontal symmetry plane.

3. Muffle according to any of the previous claims, characterized in that the back (1) is provided with peripheral flaps (2) suitable to be coupled to corresponding peripheral flaps present on the parts of the muffle adjacent to the back (1).

4. Oven characterized in that it includes a muffle according to any of the previous claims.

Ansprüche

1. Muffel, umfassend eine Mehrzahl von Teilen, die verbunden sind, um einen Garraum zu bilden, wobei die besagte Mehrzahl von Teilen eine Rückseite (1) umfasst, die mit einem zentralen flachen Bereich (3) versehen ist, welcher in der Lage ist, wenigstens einen Widerstand, einen Motor und einen Impeller aufzunehmen, wobei die besagte Rückseite (1) bei Betrachtung von vorne eine substantiell rechteckige Form aufweist, und rechtwinklig dazu eine horizontale Symmetrieebene, eine vertikale Symmetrieebene sowie zwei diagonale Ebenen, die durch die Schnittlinie der besagten Symmetrieebenen hindurchgehen sowie durch entsprechende Paare von gegenüberliegenden Ecken der besagten rechteckigen Form, dadurch gekennzeichnet, dass das Teil zwischen dem äußeren Umfang der Rückseite (1) und dem besagten, zentralen flachen Bereich (3) aus zwei flachen seitlichen Bereichen (5) besteht, deren Schnittlinien mit der besagten, horizontalen Symmetrieebene eine Neigung von weniger als 90° gegenüber der besagten, vertikalen Symmetrieebene aufweisen, aus zwei flachen oberen und unteren Bereichen (6), deren Schnittlinien mit der besagten vertikalen Symmetrieebene eine Neigung weniger als 90° gegenüber der horizontalen Symmetrieebene aufweisen, und aus vier gerundeten Bereichen mit Radien (4), welche die besagten, seitlichen Bereiche (5) mit den besagten oberen und unteren Bereichen (6) verbinden, wobei die Schnittlinien, die aus dem Schnitt der besagten, vier gerundeten Bereiche mit einer Ebene rechtwinklig zu sowohl zur Rückseite (1) als auch zu jeder der zwei besagten, diagonalen Ebenen resultieren, ein substantiell parabelförmiges Profil aufweisen.

2. Muffel gemäß Anspruch 1, dadurch gekennzeichnet, dass die Schnittlinien der zwei flachen seitlichen Bereiche (5) mit der horizontalen Symmetrieebene eine Neigung von 51°±10% gegenüber der vertikalen Symmetrieebene aufweisen, und die Schnittlinien der zwei flachen oberen und unteren Bereiche (6) mit der vertikalen Symmetrieebene eine Neigung von 6°±10% gegenüber der horizontalen Symmetrieebene aufweisen.

3. Muffel gemäß einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass die Rückseite (1) mit randseitigen Laschen (2) versehen ist, welche dazu geeignet sind, mit entsprechenden randseitigen Laschen an den an die Rückseite (1) angrenzenden Teilen der Muffel verbunden zu werden.

4. Ofen, dadurch gekennzeichnet, dass er eine Muffel gemäß einem der vorhergehenden Ansprüche aufweist.

Revendications

1. Moufle comprenant une pluralité de parties raccordées pour former une chambre de cuisson, ladite pluralité de parties comprenant une partie arrière (1) prévue avec une zone plate centrale (3) pouvant loger au moins une résistance, un moteur et une hélice, ladite partie arrière (1) ayant une forme sensiblement rectangulaire lorsqu'elle est observée depuis l'avant et étant perpendiculaire à un plan de symétrie horizontal, un plan de symétrie vertical et deux plans diagonaux passant par l'intersection desdits plans de symétrie et par des paires respectives de coins opposés de ladite forme rectangulaire, caractérisé en ce que la partie entre le périmètre externe de la partie arrière (1) et ladite zone plate centrale (3) est composée de deux parties latérales plates (5) dont les lignes d'intersection avec ledit plan de symétrie horizontal ont une inclinaison inférieure à 90° par rapport audit plan de symétrie vertical, deux parties supérieure et inférieure plates (6) dont les lignes d'intersection avec le plan de symétrie vertical ont une inclinaison inférieure à 90° par rapport au plan de symétrie horizontal et quatre parties arrondies avec des rayons (4) raccordant lesdites parties latérales (5) auxdites parties supérieure et inférieure (6), les lignes d'intersection provenant de l'intersection desdites quatre parties arrondies avec un plan perpendiculaire à la fois à la partie arrière (1) et à l'un quelconque desdits deux plans diagonaux ayant un profil sensiblement parabolique.

2. Moufle selon la revendication 1, caractérisé en ce que les lignes d'intersection des deux parties latérales plates (5) avec le plan de symétrie horizontal ont une inclinaison de 51° ±10% par rapport au plan de symétrie vertical et les lignes d'intersection des deux parties supérieure et inférieure plates (6) avec le plan de symétrie vertical ont une inclinaison de 6° ±10% par rapport au plan de symétrie horizontal.

3. Moufle selon l'une quelconque des revendications précédentes, caractérisé en ce que la partie arrière (1) est prévue avec des rabats périphériques (2) appropriés pour être couplés aux rabats périphériques correspondants présents sur les parties du moufle adjacentes à la partie arrière (1).

4. Four caractérisé en ce qu'il comprend un moufle selon l'une quelconque des revendications précédentes.

Drawing