ceramic glass cooktop with display window fixed by overmolding

Abstract

The present invention relates to a cooking plate (10) for a fixed or mobile cooking appliance comprising a base plate (11), at least one cooking zone, and at least one control and / or information zone, said control and / or information zone being formed by a window (140) separated from said base plate by at least one seal (182) made of synthetic material, characterized in that said window is fixed to the base plate by a fastening system (18) comprising said seal arranged between said window and the base plate and a connecting support (180) forming, with the base plate and the window, a mold into which the material forming said seal is injected. Fig 4

Description

Title of the invention: Glass ceramic hob with display window fixed by overmolding

[0001] The present invention relates to glass-ceramic plates or worktops. Prior art

[0002] There are various ways to display LCD screens in the display / control panel area through a glass-ceramic substrate. The KeraResin® product (transparent glass-ceramic with an opacifying layer on the underside to mask the heating elements) allows LCD screens to be used by creating a resin-free saving zone in this area. The opacity and deep black color are not always sufficient for users and the solution is not always compatible with radiators.

[0003] Another method is to use the KeraVision® substrate with opacifier but due to the transmission and coloring of the glass ceramic, a high brightness screen and color adjustment are often necessary (most screens do not have sufficient brightness and the colorimetric rendering of the LCD screen is impacted by the coloring of the substrate).

[0004] One solution envisaged is to provide the presence of a window at the level of the glass-ceramic plate, also called the main plate. Such a window consists of a transparent plate arranged in an opening of the glass-ceramic plate. Under the window, control panels or LCD screens are arranged. This window must then be fixed to the main plate. One solution envisaged is the use of a seal made of synthetic material between the main plate and the window. This seal may include systems for fixing the control panels or LCD screens.

[0005] The disadvantage of such a system is that it must withstand fairly significant constraints. A first constraint is the force applied by the user to the window. Indeed, vitroceramic hobs are tactile, involving pressure from the user on the hob to activate or deactivate functions. As the window is not integral with the main hob, the pressure exerted by the user involves a constraint on the means of fixing the window to the main hob. The hobs must also meet mechanical resistance standards (in particular standard NF EN 60335-1), in particular to withstand impacts that can simulate the falling of objects on the surface. The assembly solution must withstand other mechanical stresses such as abrasion with scouring sponges or repeated movements of kitchen utensils.The solution must be chemically resistant to repeated exposure to food and / or cleaning products. This fixing must therefore be solid and durable over time.

[0006] Second, the material used for the seal must be temperature resistant because the window is generally located close to a heating zone and therefore close to a hot cooking utensil. The seal must therefore be able to withstand the temperature of the cooking utensil placed close to or even placed on the window.

[0007] There is therefore a need for a system allowing the installation of a display window on a glass-ceramic plate ensuring mechanical resistance and thermal resistance. Summary of the invention

[0008] The present invention aims to overcome the drawbacks of the prior art by providing a cooking plate provided with a control zone which is resistant to mechanical stresses and thermal stresses.

[0009] To this end, the invention relates to a cooking plate for a fixed or mobile cooking appliance comprising a base plate having at least one cooking zone and comprising at least one control and / or information zone, said control and / or information zone being formed by a window separate from said base plate, characterized in that said window is fixed to the base plate by a fixing system comprising said seal arranged between said window and the base plate and a connecting support forming, with the base plate and the window, a mold into which the material forming said seal is injected.

[0010] According to one example, the connecting support is a profile.

[0011] According to one example, the connecting support(s) extend over the entire joint length.

[0012] According to one example, the connecting support comprises means for centering the window relative to the base plate.

[0013] According to one example, the centering means comprise at least one stud.

[0014] According to one example, the connecting support comprises means for holding a control and / or information module to the connection medium.

[0015] According to one example, the connecting support is arranged under the cooking plate.

[0016] The invention further relates to a cooking module comprising a plate according to the invention, said cooking module comprising at least one heating element arranged under the cooking zone of said cooking plate and at least one control and / or information module arranged under the window.

[0017] The invention further relates to a method for manufacturing a cooking plate for a fixed or mobile cooking appliance comprising a base plate having at least one cooking zone and comprising at least one control and / or information zone, said control and / or information zone being formed by a window separated from said base plate by at least one seal made of synthetic material, characterized in that said window is fixed to the base plate by a fixing system comprising said seal and a connecting support at least partially overmolded on said seal, said method comprising the following steps: - Provide the base plate and the window, said base plate comprising an upper face which is the visible face of the plate once mounted and a lower face; - Provide at least one connecting support; - Place the base plate on an assembly table with its upper face facing said assembly table and place the window in the opening of the base plate so as to create a gap extending between the base plate and the window; - Place the connecting bracket in contact with the window and the base plate to form at least one cavity between the gap and the connecting bracket; - Take the material forming the seal and inject it into the cavity and then let it harden

[0018] According to one example, the injection of the material forming the seal into the cavity is done through at least one opening arranged in the connecting support.

[0019] According to one example, the window and the injection plate are placed on an assembly table and in that the injection of the material forming the seal is done through at least one opening arranged on the assembly table, the window and the base plate being arranged so that the gap is opposite said at least one opening of the assembly table.

[0020] According to one example, the method comprises, before the step of injecting the material forming the seal, a step consists of placing an overmolding mold including the connecting support on the lower face in order to form at least one cavity between the overmolding mold and the connecting support.

[0021] According to one example, the overmolding mold comprises an opening through which the material forming the seal is injected. Brief description of the drawings

[0022] Other features and advantages will become clear from the description given below, for information purposes only and in no way limiting, with reference to the attached drawings, in which:

[0023] - figures 1 and 2 represent a cooking appliance according to the invention;

[0024] - [Fig.3] represents a cooking appliance mounted on a box;

[0025] - [Fig.4] represents a cooking plate of a cooking appliance mounted on a box;

[0026] - [Fig.5] represents a cooking plate provided with a window according to the invention.

[0027] - [Fig.6a] and 6b represent a window attached to a base plate with the fixing means according to the invention.

[0028] - figures 7a, 7b and 8 represent a connecting support according to the invention.

[0029] - Figures 9 to 12 represent the steps of a first embodiment of a method of fixing a window fixed to a base plate according to the invention.

[0030] - Figures 13 to 16 represent the steps of a first embodiment of a method of fixing a window fixed to a base plate according to the invention.

[0031] - Figures 17 to 18 represent a variant of the method according to the invention.

[0032] - figures 19 to 21 represent a variant of the connecting support with means centering according to the invention.

[0033] - [Fig.22] represents a cooking plate provided with a window of the supports of connection capable of carrying an information or control module according to the invention. Detailed description

[0034] In [Fig.l] a cooking appliance 1 is shown. This cooking appliance 1 comprises a cooking plate 10. This cooking plate 10 comprises a base plate 11 which may be, in particular, a glass-ceramic plate. This base plate 11 has a rectangular shape, seen from above. It may also have a circular or trapezoidal or square shape. The base plate 11 has a flat outer or upper surface 11' intended to be placed horizontally and on which the cooking utensils to be heated rest. The base plate 11 then comprises an inner or lower surface 11”, opposite the outer surface.

[0035] The base plate 11 comprises at least one cooking or heating zone 13 as seen in [Fig.2]. This cooking zone 13 is an area of ​​the base plate under which a heating element 15 is arranged. It is then understood that the heating element 15 is arranged opposite the inner surface 11”. This heating element 15 is a radiant or halogen element or a gas burner or an induction heating coil.

[0036] The base plate 11 further comprises at least one control and / or information zone 14. This control and / or information zone 14 is the place where it is possible to control the operation of the cooking zone(s) and / or where it is possible to display information relating to the operation of the cooking zone(s). However, it is possible to have a separate control zone and information zone 14 or to have one control and information zone per cooking zone. Thus, for two cooking zones 13, it is possible to have two control and information zones 14. Under each control and / or information zone, a control and / or information module is arranged.

[0037] It is then understood that the assembly of the cooking plate 10 with at least one heating element 15 and at least one control and / or information module makes it possible to obtain a cooking module.

[0038] The cooking plate 11 is capable of being placed on a structure 2, as seen in [Fig.3], according to several embodiments.

[0039] In a first embodiment, the cooking plate 10 has a single cooking function. In a first case, the cooking plate is arranged directly on the structure, this structure comprising an upper opening which is closed by the cooking plate.

[0040] In a second case, the cooking plate 10 is arranged on a structure 2 by means of a work surface. This work surface comprises an opening allowing said cooking plate to be placed on the work surface.

[0041] In a second embodiment, the cooking plate 10 has a worktop function. In this case, the cooking plate 10 is directly placed on a structure 2 to close its upper opening. The difference here is that a cooking plate acting as a worktop has a larger surface area, more than one square meter.

[0042] The control and / or information zone 14 is formed by a window 140 which is made of a material of chemical composition different from that of the base plate 11 as visible in [Fig.5]. The cooking plate 10 then comprises the base plate 11 and the window 140. It is understood by this that the material of the window can be a vitroceramic but undergoing a different treatment from that forming the base plate or can be a different material such as PMMA or a glass, soda-lime or borosilicate, tempered or hardened. Preferably, the window has a transparency and optical transmission greater than that of the base plate as well as a blur index allowing the readability of the displays / screen. The choice of the material of the window depends on the proximity of the latter to the cooking zone (compatible resistance to thermal shocks).This is because the closer the window is to the cooking area, the more likely it is to be subjected to the temperatures of hot cookware.

[0043] This window 140 has a shape similar to that of a through hole or opening 111 made on the base plate 11 as visible in [Fig.4]. The dimensions of the opening 111 made on the base plate 11 are significantly larger than the dimensions of the window. This difference in dimensions allows the presence of a gap 112 between the window 140 and the base plate 11 allowing the installation of a seal between the base plate 11 and the window 140, this seal is made of synthetic material.

[0044] The edges of the window and the edges of the opening of the base plate can be straight / flat or rounded, chamfered, beveled.

[0045] According to the invention, the window 140 is fixed to the base plate 11 by means of a fixing system 18 as visible in FIGS. 6a and 6b. This fixing system 18 comprises a connecting support 180 and a seal 182.

[0046] The fastening system 18 is arranged to allow the connection between the base plate 11 and the window 140 which is physically operated by the seal. The connection support 180 is associated with the seal 182 to provide additional mechanical strength for the entire assembly system. The connection support 180 is arranged at the lower surface of the base plate 11, i.e. under the cooking plate 10.

[0047] The seal 182 is made of a synthetic material which has adhesion characteristics with the base plate, the window and the material of the connecting support. The seal 182 can thus be a silicone-based, epoxy-based, single-component or two-component adhesive, such as for example adhesives of the novasil® brand with the references S44, S76, SP61-16, or of the Elkem® 7252 brand.

[0048] More particularly, the connecting support 180 is in the form of a flat or complex profile, that is to say having a main portion from which extends like a U-shaped or L-shaped or C-shaped profile. This profile is visible in Figures 6a and 6b. The connecting support 180 is arranged to, once placed, extend between the window, the gap and the base plate. The connecting support 180 is made of a material of the metal type or one of its alloys, carbon, a plastic or polymer or any other possible material. The material chosen is preferably resistant to a maximum temperature reached on the lower face of the vitroceramic, for example when moving a heated empty pan (for a vitroceramic 4 mm thick, the material must withstand 100°C max continuously) or for example during continuous heating.

[0049] It is then understood that the material of the connecting support, the material of the base plate and the material of the window are chosen to compensate for the differences between the different coefficients of thermal expansion of these materials.

[0050] The connecting support 180 then makes it possible to fix, to mechanically attach the window to the base plate 11.

[0051] In a first embodiment, the fixing system 18 comprises a connecting support 180. This connecting support 180 is then unique and therefore extends along the gap between the window and the base plate. The connecting support 180 is adapted to the dimensions of the window, itself designed to adapt to the size of the control / display area. The connecting support is then annular or forms a loop or frame as visible in Figures 7a, 7b.

[0052] In a second embodiment, the fixing system 18 comprises at least two connecting supports 180. The at least two connecting supports 180 are arranged to form the equivalent of an annular part as visible in [Fig.8]. then includes that the at least two connecting supports 180, when installed, extend along the entire gap between the window and the base plate. The connecting supports 180 are then identical or not, regularly distributed or not.

[0053] Furthermore, the seal 182 and the connecting support 180 cooperate so that the seal ensures the maintenance of the connecting support.

[0054] This association or cooperation is due to the method of installing the fixing system 18. The method of installing the fixing system 18 consists of molding the connecting support 180 with the seal 182.

[0055] Thus, the connecting support 180 is configured to be able, in cooperation with the base plate and the window, to serve as a mold.

[0056] The installation of the window for the manufacture of the cooking plate according to the present invention can be done in different ways.

[0057] The first step, visible in [Fig.9] consists of providing the base plate 11 and the window 140 and placing them on an assembly table. The base plate and the window are positioned so as to have the outer surface 11' resting on said assembly table. The window is arranged in the opening of the base plate previously made.

[0058] The assembly table P is, optionally, previously covered with a work sheet. This is a sheet whose adhesion properties are different from the work surface, preferably less adhesive.

[0059] Secondly, the method consists of providing at least one connecting support 180 as visible in [Fig. 10].

[0060] Next, the window 140 is centered relative to the base plate 11. This third step therefore consists of manipulating the window to ensure that the gap is constant along its entire length. Shims can be used and positioned to ensure such consistency.

[0061] After that, the connecting support 180 is placed to be laid on the base plate 11 and on the window 140, to form a mold.

[0062] Finally, the seal is put in place. The seal 182 is in the form of an injectable material which, by polymerizing or hardening, will form the seal 182.

[0063] According to a first embodiment, the connecting support 180 comprises at least one opening 181 or filling channel to allow the insertion of a filling or injection nozzle as visible in [Fig. 11]. Thus, the connecting support 180 placed on the base plate 11 and on the window 140 and the assembly table then form a cavity C. As the connecting support 180 extends over the entire length of the gap between the base plate 11 and the window 140, the cavity extends along said gap. The injected material then fills this cavity and the opening 181 as a whole as visible in [Fig. 12].

[0064] The advantage of this first embodiment is that it allows, in a single step, the connection support and the seal to be put in place while ensuring that the seal has an adequate level of finish, i.e. without the need for heavy operations to rework said seal.

[0065] According to a second embodiment visible in figures 13 to 16, the assembly table is provided with openings PI used for injection. This opening PI allows an injection nozzle to be inserted therein. The gap between the base plate and the window is arranged opposite these openings. This allows the injection nozzle to inject the material to fill the cavity.

[0066] Of course, the connecting support 180 can comprise several openings 181, filling channels distributed along its length and of different sizes so that the filling of the cavity is done more quickly and more homogeneously.

[0067] In a variant, the profile is completely overmolded. This total overmolding is carried out by the use of an overmolding mold 20 as visible in Figures 17 and 18. This overmolding mold is designed to be placed on the base plate 11 to encompass the connecting support 180. A cavity is then created between the mold 20 and the connecting support 180. The overmolding mold 20 then comprises at least one opening allowing the cavity between the overmolding mold and the connecting support to be filled with the material forming the joint. The overmolding mold can be the negative form of the connecting support 180. The connecting support 180 is then overmolded.

[0068] In the case of the first embodiment of the method, said at least one opening 181 in the connecting support allows the material of the seal to fill the cavity between the overmolding mold and the connecting support and the cavity between the connecting support and the assembly table.

[0069] In the case of the second embodiment of the method, said at least one opening in the connecting support allows the material of the seal to fill the cavity between the overmolding mold and the connecting support while the opening at the level of the assembly table allows the cavity between the connecting support and the assembly table to be filled.

[0070] The advantage of at least partially overmolding the connecting support with the material forming the seal is to allow said material to maintain the connecting support. By polymerizing, hardening, the material forming the seal adheres to the walls with which it is in contact. This adhesion is improved in the case where the connecting support comprises a surface orthogonal to the interior surface of the base plate and / or the window.

[0071] The presence of the connecting support makes it possible to provide additional rigidity to the joint. Furthermore, this makes it possible to use, for the joint, a temperature-resistant material without worrying about its mechanical properties, these being provided by the support of link 180.

[0072] In a variant, the connecting support 180 comprises centering means 184 as visible in Figures 19 to 22. These centering means consist of at least one stud 185. This stud extends from the connecting support. This stud 185 is made of the same material as the connecting support or attached to it. The stud 185 has a circular or square or rectangular section. The stud is punctual or extends over at least part of the length of the connecting support.

[0073] The pad 185 comprises a constant or non-constant width. In the case of a non-constant width, the pad narrows at its end, for example in a conical shape. This shape is advantageous in that it makes it possible to free up space between the pad and the base plate and / or the pad and the window.

[0074] Preferably, the fixing system 18 comprises at least two centering means 184. These at least two centering means 184 are arranged on adjacent sides or are angularly offset. These two centering means make it possible to wedge the window relative to the base plate and thus obtain a gap between said window and the base plate which is constant over its entire length as visible in [Fig. 16].

[0075] In another variant visible in [Fig.22], the connecting support comprises holding means 186 in order to hold, fix the control and / or information module 17. This holding function makes it possible to do without the use of specific means for holding said control and / or information module. This holding function is ensured by a specific shape of the connecting support. The connecting support comprises at least one holding hook 187. This holding hook 187 extends parallel to the plane of the window in the direction of the window. This holding hook is arranged so that the control and / or information module is inserted between said hook and a support surface. This support surface may be the window or may be a portion of the connecting support.

[0076] The advantage of this variant is that it allows for a single step in which the connecting support is put in place as well as the putting in place of the control and / or information module 17 via the holding means 186. This single step makes it possible to simplify the assembly process.

[0077] In an alternative, the holding means 187 comprise a support tab pierced for the passage of a screw allowing the control and / or information module to be screwed to the connection support.

[0078] In a variant of the method, the connecting support(s) comprise centering means. In this case, the centering step is superfluous. Indeed, when fixing the connecting support(s), the centering means, in the form of at least one stud, are inserted into the gap between the window and the base plate. This insertion allows automatically move the window to obtain a constant gap.

[0079] In a variant, the window 140 comprises an opacifying layer on its upper or lower surface. This opacifying layer is arranged at the periphery of said window. This opacifying layer makes it possible to hide the fixing system 18 arranged under the cooking plate 10. This opacifying layer therefore has a width defined to operate such a function of masking the fixing system. This opacifying layer is a paint, an enamel or any other layers which would fulfill this function.

[0080] In a variant of the method, the placement on the assembly table consists of placing the connecting support on said assembly table. Then the base plate and the window are placed on said assembly table so that the connecting support is positioned under the gap between said base plate and the window. Shims are possible to support the base plate and the window. A cover placed on the base plate and the window makes it possible to form a cavity. The cover comprises at least one opening through which the material of the seal 182 is injected. In this case, the connecting support does not comprise an opening 181.

[0081] Of course, the present invention is not limited to the illustrated example but is susceptible to various variants and modifications which will appear to those skilled in the art.

Claims

Claims

1. Cooking plate (10) for a fixed or mobile cooking appliance comprising a base plate (11) at least one cooking zone and comprising at least one control and / or information zone, said control and / or information zone being formed by a window (140) separated from said base plate by at least one seal (182) made of synthetic material, characterized in that said window is fixed to the base plate by a fixing system (18) comprising said seal arranged between said window and the base plate and a connecting support (180) forming, with the base plate and the window, a mold into which the material forming said seal is injected.

2. Plate according to claim 1, in which the connecting support (180) is a profile.

3. Plate according to one of claims 1 or 2, in which the connecting support(s) (180) extend over the entire length of the gap.

4. Plate according to one of claims 1 to 3, in which the connecting support comprises means for centering the window relative to the base plate.

5. Plate according to the preceding claim, in which the centering means comprise at least one stud.

6. Plate according to one of claims 1 to 5, in which the connection support comprises means for holding a control and / or information module on the connection support.

7. Method for manufacturing a cooking plate for a fixed or mobile cooking appliance comprising a base plate having at least one cooking zone and comprising at least one control and / or information zone, said control and / or information zone being formed by a window separated from said base plate by at least one seal made of synthetic material, characterized in that said window is fixed to the base plate by a fixing system comprising said seal and a connecting support at least partially overmolded on said seal, said method comprising the following steps: - Providing the base plate and the window, said base plate comprising an upper face which is the visible face of the plate once mounted and a lower face; - Providing the at least one connecting support; - Place the base plate on an assembly table with its upper face facing said assembly table and place the window in the opening of the base plate so as to create a gap extending between the base plate and the window; - Place the connecting support in contact with the window and the base plate to form at least one cavity between the gap and the connecting support; - Take the material forming the joint and inject it into said cavity then harden it

8. Manufacturing method according to the preceding claim, in which the injection of the material forming the seal into the cavity is done through at least one opening arranged in the connecting support.

9. Manufacturing method according to claim 7, in which the window and the injection plate are placed on an assembly table and in that the injection of the material forming the seal is carried out through at least one opening arranged on the assembly table, the window and the base plate being arranged so that the gap is opposite said at least one opening of the assembly table.

10. Manufacturing method according to one of claims 7 to 9, in which it comprises, before the step of injecting the material forming the seal, a step consisting of placing an overmolding mold including the connecting support on the lower face in order to form at least one cavity between the overmolding mold and the connecting support.

11. A manufacturing method according to claim 10, wherein the overmolding mold comprises an opening through which the material forming the seal is injected.

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