EP2935998B1

EP2935998B1 - Method for attaching an oven seal and oven seal

Info

Publication number: EP2935998B1
Application number: EP13826961.8A
Authority: EP
Inventors: Fabio Gambardella
Original assignee: Whirlpool EMEA SpA
Current assignee: Whirlpool EMEA SpA
Priority date: 2012-12-19
Filing date: 2013-12-18
Publication date: 2020-07-15
Anticipated expiration: 2033-12-18
Also published as: WO2014097180A3; EP2935998A2; WO2014097180A2

Description

The present invention relates, in a general aspect thereof, to a method for fastening an oven seal and to a seal of an oven. The oven may be an embedded oven, i.e. a self-standing household appliance which is inserted into a piece of furniture, or it may be a part of a bigger household appliance, such as a gas cooker, although the present invention is also applicable to microwave ovens and the like (i.e. not necessarily gas ovens).
The ovens which have been taken into consideration herein are muffle-type ones, i.e. those with a body having a substantially cubic or parallelepiped shape, which circumscribes the cavity where the foods to be cooked must be introduced, and which is closed at the front by a door; depending on the adopted solution, the latter is normally vertically or horizontally hinged to the muffle.
In order to prevent heat dispersion from the inside of the muffle towards to outside environment, due to the hot air tending to flow out by convection, it is known to add a seal to prevent air leaks between the oven door and the muffle.
The seals used for oven applications are generally made of a soft synthetic material and have an inner channel that allows the formation of an air cushion: the latter increases the softness of the seal, thereby improving its sealing effect, even' after the door and the muffle have undergone differential thermal deformations.
Furthermore, a seal thus conceived can dampen the contact of the door against the muffle when it is closed; in this respect, it must be pointed out that oven doors are usually mounted by means of hinges that have an elastic behaviour, so that they are kept firmly closed with some force.
One example of this type of seal is known from German patent application DE 102009026932 . Another example of such a seal is revealed in European patent application EP 0 697 568 A2 .
The prior art describes a seal of the above-mentioned type, in which holes are provided through its entire thickness, which constitute air passages from/to the inside of the seal.
The latter is secured to the oven muffle by engaging a number of protruding teeth, presumably into matching cavities provided along the edge of the mouth of the muffle.
Although effective, this solution appears to be costly in that the seal has a very complex profile, which is due to the presence of the teeth for fastening it to the muffle, of the inner channel and of the air passage holes. Furthermore, the shape of the seal suggests that the oven muffle should have cavities for inserting the teeth of the seal's attachment base, thus requiring complex manufacturing steps.
In fact, muffles are usually made of metal sheet, and therefore it is not clear how cavities having a profile suitable for engaging the teeth of the seal's attachment base can be made.
One technical problem at the basis of the present invention is therefore to provide a method for fastening a seal for the door of a muffle-type oven, the implementation characteristics of which allow it to overcome the limits of the prior art; it is however worth pointing out that the seal may be fastened either to the door or to the muffle.
The general idea that solves this problem is to apply the seal without using any external fastening means, such as screws, rivets, adhesives, brackets or the like: this will simplify the assembly operations and will reduce the costs thereof.
More specifically, the idea that solves the above-mentioned problem is to provide systems for joining the seal to the oven's components, whether the door, the muffle or any other part: in this manner, mounting the seal will be simpler also because, in addition to not requiring any external fastening means such as screws, rivets, adhesives, etc., it will take less time.
It is also possible that the seal is arranged between the muffle and the frame mounted frontally thereto, where the oven's controls are usually located.
This will allow fastening the seal while applying the frame to the muffle, thus reducing the number of oven assembly steps.
The seal of the invention may also have a simplified shape, since it is de facto sufficient that it has a base portion that prevents it from detaching from the muffle and the frame of the oven, and another portion, connected to the base portion, to provide a sealing action against the oven door.
The implementation steps of the seal fastening method according to the invention, as well as the features of a seal according to the invention, are specifically set out in the claims appended to this description.
The invention will become more apparent from the following description of one preferred but not limiting example of embodiment thereof as shown in the annexed drawings, wherein:

Figure 1 shows an axonometric view of a muffle of an oven;
Figure 2 shows a front view of the muffle of Figure 1, with a frame applied frontally thereto;
Figure 3 is a sectional view along line A-A of Figure 2 of the muffle according to the invention;
Figure 4 is an enlarged view of a detail of Figure 3;
Figure 5 shows an axonometric view of a muffle in accordance with a second embodiment of the invention;
Figure 6 is a front view of the muffle of Fig. 5;
Figure 7 is a sectional view along line A-A of Figure 6 of the muffle;
Figures 8 and 9 show respective enlarged views of details concerning the installation of the seal on the muffle of Figures 5 to 7;
Figure 10 is a front view of an oven door;
Figure 11 is an enlarged sectional view along line A-A of Fig. 10;
Fig. 12 is a sectional view along line B-B of the oven door of Fig. 10;
Fig. 13 is an enlarged view of a detail of Fig. 12.

With reference to the above-listed drawings, particularly to Figures 1 to 4, 1 designates as a whole a muffle of an oven in accordance with the present invention; said muffle, which can be manufactured by using any method known in the art, has a substantially cubical shape, with a top wall or ceiling 2, a bottom 3, two opposed side walls 4 and 5, and a back wall 6, which circumscribe a cooking cavity 7.
The muffle 1 has an opening 8 at the front to allow access to the inner cavity 7, on the edge of which a seal 10 according to the invention is applied; said seal is more clearly visible in Figures 2 and 4, which show its elongated tubular extension, with a channel 11 extending longitudinally and a lip 12 projecting outwards from the muffle.
The seal 10 also has an attachment base 14 to be attached to the edge 9 of the mouth 8 of the muffle, and a frame 15; the edge 9 is preferably made of metal sheet with a substantially C-shaped profile, with a folded flap 9a on which a portion 14a of the attachment base 14 of the seal is applied.
The other portion 14b of the base 14 of the seal engages with an edge 15a of the frame 15 which, when the latter is applied to the muffle 1, is coupled to the edge 9.
As can be seen, when the frame 15 is assembled to the muffle 1, the portions 14a, 14b of the base 14 of the seal 10 engage with the flaps 9a, 15a, respectively, of the muffle and of the frame, thus preventing the seal from moving outwards.
Advantageously, the seal further comprises a flat intermediate section 17 that connects the attachment base 14 to the area where the channel 11 is located.
In addition to acting as a connection between the base 14 and the front region of the seal, this intermediate section also serves as a sealing element between the muffle 1 and the frame 15, thereby preventing them from coming into direct contact and also, thanks to the elastic characteristics of the seal material, compensating for differential thermal expansions.
The seal 10 is thus kept secured to the edge 9 of the opening 8 of the muffle without needing any further means, such as adhesives, screws or the like.
It follows, therefore, that the installation of the seal 10 on the muffle 1 is a rather simple operation, which can be carried out either manually or automatically and which only requires, as a matter of facts, that the portions 14a, 14b of the base be coupled to the flaps 9a, 15a of the edge of the muffle and of the frame.
After that, the seal will stay trapped between the latter, without any possibility of being removed from the front, thanks to the attachment base 14, or from the back, thanks to the presence of the channel 11.
This result is attained without applying any fastening means to the seal, such as screws, clamps, adhesives or the like, since de facto it is the frame 15 itself that acts as a seal fastening means.
In this context, it is worth highlighting the advantageous action exerted by the lip 12 of the seal, whose projecting configuration allows it to elastically dampen the shocks against the oven door (not shown in the drawings) through an action similar to that of the channel 11 but, unlike the latter, not requiring any air vent apertures, since the lip 12 is de facto an appendix without a closed inner space.
It can be easily understood from the above description how the method for fastening the seal 10 can solve the technical problem addressed by the invention.
In fact, the seal 10 can be fastened without having to provide a complex arrangement, since it only requires a base 14 which is sufficiently thick to not be allowed to pass through the space between the frame 15 and the muffle 1, so that it cannot come off.
This can be done very easily, and the possible embodiments are not limited to the preferred embodiment shown in the drawings, with the two portions 14a, 14b having a groove-like shape into which the edges of the flaps 9a, 15a are engaged, since such channels may be absent.
At the same time, it must be pointed out that no particular processing or shape is required for the muffle or the frame, e.g. by pressing or another mechanical machining (shearing, bending, etc.).
In fact, the shapes shown in the drawings are those commonly used in known applications.
Of course, the invention as described so far may be subject to variations; one of such variations will be described below with reference to Figures 5 to 13, wherein the various items are designated by reference numerals followed by an apostrophe.
Therefore, 1' indicates as a whole a muffle of an oven in accordance with this variation of the present invention; said muffle, which may be manufactured by using any method known in the art, has a substantially cubical shape, with a top wall or ceiling 2', a bottom 3', two opposed side walls 4' and 5', and a back wall 6', which circumscribe a cooking cavity 7'.
The muffle 1' has an opening 8' at the front to allow access to the inner cavity 7', on the edge of which a seal 10' according to the invention is applied; said seal is more clearly visible in Figures 8 and 9, which show its elongated tubular extension, with a channel 11 extending longitudinally and a lip 12' extending outwards from the muffle.
The seal 10' also has an attachment base 14' to be attached to the edge 9' of the mouth 8' of the muffle; the edge is made of metal sheet with a substantially C-shaped profile, on which the seal 10' is applied.
To this end, the base 14' of the seal has openings 16' arranged at a predetermined distance of a few centimetres, depending on the dimensions of the muffle, into which a tab 18' projecting from the edge 9' of the mouth of the muffle engages.
In accordance with the invention, the tab is obtained by pressing the metal sheet used for making the muffle, so as to form a fastening system to be engaged with the seal.
Advantageously, when the tab 18' is folded in order to secure the seal 10', a seat 19', juxtaposed to the opening 16' in the base 14' of the seal, will be formed on the metal sheet of the muffle 1': this will allow a free air flow to and from the channel 11' of the seal.
The seal 10' will thus be kept secured to the edge 9' of the opening 8' of the muffle without needing any further means, such as adhesives, screws or the like.
It follows, therefore, that the installation of the seal 10' on the muffle 1' is a rather simple operation, which can be carried out quickly, whether manually or automatically, and which only requires, as a matter of facts, that the tabs 18 be inserted into the openings 16'.
Optionally, the tabs may then be folded subsequently to clinch the seal 10 to the muffle .
Furthermore, the openings 16' in the base 14' of the seal also act as vent holes for the air contained therein, in accordance with an already known teaching: however, unlike the prior art, in the present invention the openings 16 also serve as seal fastening elements, thereby performing a dual function and leading to clear advantages in terms of efficiency and costs.
In addition to these advantageous effects, it is necessary to point out that the seats 19' which are formed on the metal sheet when folding the tabs 18' promotes the flow of air to and from the inner channel 11' of the seal.
In this context, it is also worth highlighting the advantageous action exerted by the lip 12' of the seal, whose projecting configuration allows it to elastically dampen the shocks against the oven door (not shown in the drawings) through an action similar to that of the channel 11' but, unlike the latter, not requiring any air vent apertures, since the lip 12' is de facto an appendix without a closed inner space.
It can be easily understood from the above description how the method for fastening the seal 1 can solve the technical problem addressed by the invention.
In fact, the seal 10' can be fastened without having to provide a complex arrangement, since it only requires the presence of openings 16' in the base 14', which can be made easily and which also act as air passage holes.
The same applies to the tabs 18', which can be easily obtained from the metal sheet used for making the edge 19' of the muffle, e.g. by pressing or another mechanical machining (shearing, bending, etc.).
The above description of the invention is also applicable to the case wherein the seal 10 is applied to the door 20' of the oven, as opposed to the muffle 1.
In fact, with reference to Figures 10-13, where items structurally or functionally equivalent to the previous ones are designated by the same reference numerals, it can be observed that also in this case the seal 10' is fastened to the door 20' by means of tabs 18' formed thereon, which engage into openings 16' provided in the base 14' of the seal.
Therefore, the same considerations expressed above in regard to the advantageous results achieved by the invention will still apply, with the addition of the possibility of installation on both the muffle 1 and the door 20', thus obtaining a clear economical advantage compared to the typical situations where different seals must be used for muffles and doors.

Claims

Method for fastening an oven seal (10), comprising the following steps:
- providing a seal (10) comprising an attachment base (14) with first and second portions (14a,14b) having: a respective substantially groove-like shape to be attached to a muffle (1) and/or a door (20) of the oven, a channel (11) extending along the longitudinal direction, an intermediate section (17) extending between said attachment base (14) and said channel (11), and a lip (12) on said channel (11) extending therefrom;

- applying a frame (15) to the muffle (1) by interposing the intermediate section (17) of the seal (10) between respective edges (9a, 15a) of the muffle (1) and of the frame (15),

- fastening the seal by engaging it with the edges (9a, 15a) of the muffle (1) and of the frame (15), and by keeping the lip (12) projecting outwards from the muffle,
thereby avoiding and/or limiting the use of screws, rivets, adhesives, brackets and/or other traditional fastening means.
Oven for carrying out the method according to claim 1, comprising a muffle (1) in which there is a cavity (7) for cooking foods, a door (20) for closing the muffle (1), a frame applied frontally to the muffle, a seal (10) for sealing between the door (20) and the muffle (1) in the closed condition thereof, and wherein a substantially flat intermediate section (17) of the seal is at least partially interposed between an edge (15a) of the frame (15) and an edge (9a) of the muffle (1),
the seal (10) comprising an attachment base (14) with first and second portions (14a,14b) which have a respective substantially groove-like shape, and are engaged with the edges (9a, 15a) of the muffle (1) and of the frame (15), respectively, so that the edge (15a) of the frame (15) is coupled to the edge (9a) of the muffle (1); a channel (11) extending along the longitudinal direction of the seal,
characterized in that the seal (10) comprises a lip (12) on said channel (11) and projecting outwards from the muffle (1).
Oven according to claim 2, wherein the muffle (1) and the frame (15) comprise respective folded flaps (9a, 15a) where their edges engage the attachment base (14) of the seal (10).
Oven according to claim 2 or 3, wherein the seal comprises a lip (12) projecting from the muffle (1), against which the door (20) abuts.
Seal of an oven according to any one of claims 2 to 4, having an elongated tubular shape or extension and comprising an attachment base (14) to be attached to a muffle (1), a channel (11) extending in the longitudinal direction, and an intermediate section (17) extending between the attachment base (14) and the channel (11), which is substantially flat, wherein
the attachment base (14) comprises first and second portions (14a, 14b) having a respective substantially groove-like shape, into which the edges of the flaps (9a, 15a) of the muffle (1) and of the frame (15), respectively, engage, characterized in that the seal (10) comprises a lip (12) on said channel (11) and projecting outwards from a muffle (1), when the seal is in operation on the oven.
Seal of an oven according to claim 5 , comprising an attachment base (14') to be attached to a muffle (1') or to a door (20') of the oven, a channel (11') longitudinally extending inside the seal, a plurality of openings (16') arranged along the attachment base (14') to allow fluidic communication between the channel (11') and the outside of the seal, characterized in that it comprises a lip (12') projecting on the side opposite to that of the attachment base (14').