METAL COOKING SUPPORT THAT CAN BE HEATED BY INDUCTION

Abstract

- The invention relates to a metal cooking support (10) compatible with induction heating, having a cooking face and a heating face (12), comprising a metal substrate (2) made of aluminum or aluminum alloy, as well as an expanded metal insert (3) made of ferritic stainless steel, said expanded metal insert (3) being inserted at least partially into the metal substrate (2) on the side of the heating face (12). - According to the invention, the expanded metal insert (3) has a strand thickness of between 0.45 and 1 mm, preferably between 0.5 and 0.6 mm, and a front transparency of less than or equal to 50%, preferably less than or equal to 40%, more preferably less than or equal to 30%. - The invention also relates to a culinary article and an electrical cooking appliance comprising such a metal cooking support (10). - Figure for abstract: Figure 1

Description

Title of the invention: METAL COOKING SUPPORT CAPABLE OF BEING HEATED BY INDUCTION

[0001] The present invention relates to the technical field of metal cooking supports compatible with induction heating, for cooking or heating food. Such metal cooking supports can be used with an induction heating device such as an induction hob placed on or integrated into a worktop, or an induction heating zone integrated into an electrical cooking appliance.

[0002] The present invention relates in particular, but not exclusively, to metal cooking supports forming a cooking container.

[0003] The present invention also relates to culinary articles comprising a metal cooking support associated with at least one gripping member. If desired, the gripping member(s) may be removable or detachable relative to the metal cooking support.

[0004] The present invention also relates to electrical cooking appliances comprising a metal cooking support associated with an induction heating device.

[0005] It is known to produce kitchen articles comprising a metal body made of aluminum, which are compatible with induction heating, using a metal insert made of ferromagnetic metal assembled with the bottom of said metal body.

[0006] Document EP0509860 describes, for example, in the embodiment illustrated in Figure 12, a metal insert made in the form of a perforated sheet. Such a construction makes it possible to produce cookware compatible with induction heating, which heat satisfactorily.

[0007] A disadvantage of this type of embodiment, however, lies in the fact that it is necessary to have a press having a relatively large striking tonnage in order to correctly assemble said metal body with said insert. Another disadvantage of this type of embodiment also lies in the fact that it is difficult to reduce the thickness of the metal body below 3 mm, while maintaining deformations of the bottom which remain acceptable over the course of uses.

[0008] Document EP0509860 also describes in the embodiment example illustrated in Figure 15 a metal insert made of expanded metal. However, this document does not present any particular advantage associated with the use of such a metal insert.

[0009] Document US2015 / 090725 discloses a culinary article comprising an insert in expanded metal in the bottom of said cookware, to achieve compatibility with induction heating. This document mentions in particular inserts with a thickness of 0.5 to 1 mm, with a strand width of 0.5 to 1 mm, and openings of 3 to 4 mm wide. However, the use of such inserts does not lead to sufficiently satisfactory induction heating performance.

[0010] Various aspects of the present invention aim to overcome the drawbacks of the prior art by proposing a metallic cooking support compatible with induction heating, which is easy to produce, and which has satisfactory coupling on induction heating plates designed to operate mainly with cooking supports comprising a solid base made of ferritic stainless steel.

[0011] A first aspect of the present invention relates to a metal cooking support compatible with induction heating, having a cooking face and a heating face, comprising a metal substrate made of aluminum or aluminum alloy, as well as an expanded metal insert made of ferritic stainless steel, said expanded metal insert being inserted at least partially into the metal substrate on the heating face side, due to the fact that the expanded metal insert has a strand thickness of between 0.45 and 1 mm, preferably between 0.5 and 0.6 mm, and a front transparency of less than or equal to 50%, preferably less than or equal to 40%, more preferably less than or equal to 30%.These provisions appear necessary to ensure satisfactory coupling on induction heating plates designed to operate mainly with cooking supports comprising a solid base of ferritic stainless steel, usually in the form of a perforated plate.

[0012] Preferably the frontal transparency is greater than or equal to 20%, more preferably greater than or equal to 24%.

[0013] The expanded metal insert may in particular have a strand width of between 0.5 mm and 1 mm. These strand width values are usual for the strand thicknesses envisaged.

[0014] The expanded metal insert may in particular have an inter-strand opening diameter less than or equal to 2.3 mm, preferably less than or equal to 1.8 mm, more preferably less than or equal to 1.1 mm. These inter-strand opening diameter values are usual for the strand thicknesses envisaged. For higher inter-strand opening diameter values, cases of unstable operation have been noted.

[0015] Preferably the inter-strand opening diameter is greater than or equal to 0.8 mm, more preferably greater than or equal to 0.9 mm.

[0016] The metal substrate may in particular have a substrate thickness less than or equal to 3.4 mm, preferably less than or equal to 3 mm, more preferably in less than or equal to 2.5 mm. Compared to an insert made in the form of a perforated plate, the use of an insert made of expanded metal makes it possible to reduce the efforts required to implant the insert in the metal substrate, which makes it possible to reduce the thickness of the metal substrate.

[0017] Preferably the substrate thickness is greater than or equal to 2 mm, more preferably greater than or equal to 2.2 mm.

[0018] If desired, the metal substrate can be made from recycled alloy. Recycled alloys are in fact harder than the corresponding new alloys.

[0019] The expanded metal insert can in particular be made of type 430 stainless steel.

[0020] According to one embodiment, the strand thickness is 0.6 mm.

[0021] According to one embodiment, the strand width is 1 mm.

[0022] According to one embodiment, the inter-strand opening diameter is 1 mm.

[0023] The metal cooking support may have a bottom configured to rest on an induction heating device.

[0024] According to one embodiment, the bottom is flat.

[0025] A side wall may rise around the bottom to form a cooking vessel.

[0026] The metal substrate may carry a non-stick coating forming a cooking surface of the cooking face. The non-stick coating may in particular be a PTFE type coating, or a ceramic type coating, or a sol-gel type coating, or a silicone resin-based coating, or a silicone-polyester resin-based coating. The non-stick coating may be single-layer or multi-layer. If desired, other non-stick coatings compatible with food contact may be considered.

[0027] The metal substrate and the expanded metal insert may carry a protective coating forming a heating surface of the heating face. The protective coating may in particular be a PTFE type coating, or an enamel type coating, or a lacquer type coating, or a ceramic type coating, or a sol-gel type coating, or a silicone resin-based coating, or a silicone-polyester resin-based coating. The protective coating may be single-layer or multi-layer. If desired, other protective coatings may be considered.

[0028] A second aspect of the present invention relates to a culinary article comprising a metal cooking support and a gripping member mounted on the metal cooking support, in which the metal cooking support conforms to at least one of the aforementioned characteristics.

[0029] A third aspect of the present invention relates to an electrical cooking appliance comprising a metal cooking support associated with an induction heating zone, in which the metal cooking support conforms to at least one of of the aforementioned characteristics.

[0030] Other characteristics and attributes of the present invention will appear more clearly on reading the following detailed description of exemplary embodiments and variants, taken without any limitation being implied, illustrated in the appended figures, in which:

[0031] [Fig.l] represents a bottom view of an exemplary embodiment of a metal cooking support according to the invention,

[0032] [Fig.2] represents a partial schematic view of an expanded metal insert used in the metal cooking support illustrated in [Fig.l].

[0033] [Fig.3] represents a partial schematic sectional view of the metal cooking support illustrated in [Fig.l].

[0034] [Fig.4] shows a partial schematic sectional view of a metal cooking support comprising the expanded metal insert illustrated in [Fig.2].

[0035] [Fig. 5] represents a schematic view in elevation and in cross-section of an exemplary embodiment of a culinary article comprising a metal cooking support according to the invention.

[0036] [Fig. 6] represents a schematic view in elevation and in cross-section of an exemplary embodiment of an electrical cooking appliance comprising a metal cooking support according to the invention.

[0037] [Fig.l] illustrates an exemplary embodiment of a metal cooking support 10 compatible with induction heating. The metal cooking support 10 has a cooking face 11 and a heating face 12. The heating face 12 has a bottom 13 configured to rest on an induction heating device. Depending on the induction heating device used, the bottom 13 may be flat, or not, for example curved.

[0038] The metal cooking support 10 comprises a metal substrate 2 made of aluminum or aluminum alloy. The metal substrate 2 may in particular be made of recycled alloy, such alloys usually being harder than the corresponding new alloys.

[0039] The metal cooking support 10 comprises an expanded metal insert 3 made of ferritic stainless steel. The expanded metal insert 3 may in particular be made of type 430 stainless steel. The expanded metal insert has a mesh network of strands 30 defining inter-strand openings 31.

[0040] As best seen in [Fig.2], the expanded metal insert 3 has a strand thickness EB, a strand width LB, and an inter-strand opening diameter OB. The expanded metal insert 3 also has a frontal transparency which corresponds to the ratio of the open surface between the strands to the total surface.

[0041] The expanded metal insert 3 is inserted at least partially into the substrate me metal 2, on the side of the heating face 12, in order to make the metal cooking support 10 compatible with induction heating.

[0042] [Fig. 3] schematically illustrates the expanded metal insert 3 inserted into the metal substrate 2. As best seen in [Fig. 3], the metal substrate 2 has a substrate thickness ES. The substrate thickness ES is advantageously less than or equal to 3.4 mm, preferably less than or equal to 3 mm, more preferably less than or equal to 2.5 mm. Preferably the substrate thickness ES is greater than or equal to 2 mm, more preferably greater than or equal to 2.2 mm.

[0043] As best seen in [Fig. 3], a side wall 16 (partially shown) rises around the bottom 13 to form a cooking container 20.

[0044] As shown in [Fig. 3], the expanded metal insert 3 extends only in the area of the bottom 13 without reaching the side wall 16. More particularly, the expanded metal insert 3 extends throughout the area of the bottom 13. It should be noted that the representation in [Fig. 3] is schematic and that the expanded metal insert 3 does not entirely cover the bottom 13. In other words, the metal substrate 2 is visible through the inter-strand openings 31 of the expanded metal insert 3. As a variant, the expanded metal insert 3 does not necessarily extend over the entire bottom 13. As a further variant, the expanded metal insert 3 could extend over at least a portion of the side wall 16.

[0045] [Fig. 4] illustrates an alternative embodiment in which the metal cooking support 10 comprises a non-stick coating 1 and a protective coating 5. The non-stick coating 1 forms a cooking surface 14 of the cooking face 11. The protective coating 5 forms a heating surface 15 of the heating face 12. The metal substrate 2 carries the non-stick coating 1 on the side of the cooking face 11. The metal substrate 2 and the expanded metal insert 3 carry the protective coating 5 on the side of the heating face 12. The expanded metal insert 3 is inserted into the metal substrate 2 on the side of the heating face 12. Due to the inter-strand openings 31 between the strands 30 of the expanded metal insert 3, the expanded metal insert 3 does not completely cover the metal substrate 2 in the area of the bottom 13.

[0046] The non-stick coating 1 is for example a PTFE (PolyTetraFluoroEthylene; in other words, a PTFE-type fluorinated resin-based coating), or a ceramic-type coating, or a sol-gel-type coating (in other words, a coating synthesized by sol-gel method). The non-stick coating 1 may be single-layer or multi-layer. The non-stick coating 1 may also be a coating(s) based on silicone resin or silicone-polyester resin.

[0047] The protective coating 5 is for example a PTFE type coating (in other words, a fluororesin based coating of PTFE type), or an enamel type coating, or a lacquer type coating, or a ceramic, or a sol-gel type coating (in other words, a coating synthesized by sol-gel method). The protective coating 5 may be single-layer or multi-layer. The protective coating 5 may also be a coating(s) based on silicone resin or silicone-polyester resin.

[0048] Tests were carried out with cooking supports 10 comprising different expanded metal inserts 3 to evaluate their coupling performance on several induction heating plates.

[0049] Table 1 summarizes the characteristics of samples #1 to #4 of expanded metal insert 3 which were inserted into metal substrates 2 of diameter 28 cm and thickness 2.4 mm made of aluminum alloy to obtain cooking supports 10 Ref. 1 to Ref.4.

[0050] [Tables 1] EB (mm) LB (mm) OB (mm) TF (%) #1 0.6 0.6 3.10 55 #2 0.6 0.6 2.25 46 #3 0.6 0.8 1.75 39 #4 0.6 1 1.00 26

[0051] Table 2 shows the different induction heating plates used and the results of the tests carried out with the cooking supports 10 Ref.1 to Ref.4.

[0052] [Tables2] MIELE® BRANDT® BSH® BSH® Ref KM6114 BPI6320X PIJ631FB1E PIJ631FB1E 0 inductor (mm) 270 270 210 210 Position P9 PBoost P9 PBoost Nominal power (W) 1800 2200 2200 3700 Power Ref.l (W) 520-548 1560-1570 1680-1737 2200-2700(*) Power Ref.2 (W) 870-885 1750-1750 1776-1865 3070-3070 Power Ref.3 (W) 845-1125 1730-1860 1860-1990 3065-3065 Power Ref.4 (W) 1500-1590 2000-2020 2070-2100 3300-3300

[0053] (*) unstable operation oscillating between 2200 and 2700 W.

[0054] The 4 cooking supports 10 Ref.l to Ref.4 tested are lighter than conventional cooking supports comprising an insert made of ferromagnetic material in the form of in the form of a perforated plate, due to the smaller quantity of material used to produce the expanded metal insert 3, as well as due to the reduced thickness of the metal substrate 2.

[0055] The 4 cooking supports 10 Ref.1 to Ref.4 tested have satisfactory resistance to deformation, although the thickness of the metal substrate 2 is thinner than that usually used with perforated plate type ferromagnetic inserts, due to the lower mechanical strength of the expanded metal insert 3 compared to a perforated plate. This results in less sensitivity of the cooking supports 10 to deformations due to the differential expansion of the materials of the metal substrate 2 and the expanded metal insert 3. The expanded metal insert 3 also requires a lower insertion force in the metal substrate 2 than the force necessary to implant a perforated plate in said metal substrate 2, which also makes it easier to reduce the thickness of the metal substrate 2.

[0056] The cooking support 10 Ref.l has unsatisfactory performances with absorbed powers which can be notoriously lower than those of the other cooking supports 10 Ref.2 to Ref.4, and with a problem of coupling at high power in booster position. It should be noted that the frontal transparency TF of the cooking support 10 Ref.l, of the order of 55%, is the most important of the 4 cooking supports 10 Ref.l to Ref.4.

[0057] The cooking support 10 Ref.2 with a front transparency TF of the order of 46% presents more satisfactory performances, even if behind the performances of the cooking supports 10 Ref.3 and Ref.4.

[0058] The cooking support 10 Ref.3 with a front transparency TF of the order of 39% presents even more satisfactory performances, even if behind the performances of the cooking support 10 Ref.4.

[0059] Finally, the cooking support 10 Ref.4 with a front transparency TF of the order of 26% presents the most satisfactory performances of the 4 cooking supports 10 Ref.1 to Ref.4 tested, these performances being close to the nominal powers of the cooking plates (by comparison, the performances of the articles with solid stainless steel bottom can go beyond the nominal powers of the cooking plates, approximately 5% above said nominal powers).

[0060] Thus in the samples tested, the strand thickness EB is advantageously between 0.45 and 1 mm, preferably between 0.5 and 0.6 mm. The front transparency TF is advantageously less than or equal to 50%, preferably less than or equal to 40%, more preferably less than or equal to 30%. Preferably the front transparency is greater than 20%, more preferably greater than or equal to 24%. The strand width LB is advantageously between 0.5 mm and 1 mm. The inter-strand opening diameter OB is advantageously less than or equal to 2.3 mm, preferably less than or equal to 1.8 mm, more preferably less than or equal to 1.1 mm. Preferably the inter-strand opening diameter OB is greater than or equal to 0.8 mm, more preferably greater than or equal to 0.9 mm.

[0061] According to an advantageous embodiment, the strand thickness EB is 0.6 mm, the strand width LB is 1 mm, the inter-strand opening diameter OB is 1 mm. Such a geometry corresponds to a front transparency TF of 26%, which presents very satisfactory induction heating performances.

[0062] Figures 5 and 6 illustrate a metal cooking support 100 having a heating face 110. The metal cooking support 100 may in particular be formed by the metal cooking support 10 illustrated in Figures 1 and 3 or by the metal cooking support 10 illustrated in [Fig.4]. The metal cooking support 100 comprises a side wall 123 rising around a bottom 122 of the heating face 110 to form a cooking container 124. As a variant, the metal cooking support 100 does not necessarily form a cooking container 124. The metal cooking support 100 may in particular form a cooking plate.

[0063] [Fig. 5] illustrates a culinary article 140 comprising a metal cooking support 100 forming the cooking container 124 and a gripping member 150 mounted on the cooking container 124. In the exemplary embodiment illustrated in [Fig. 5], the gripping member 150 is fixed to the cooking container 124 by at least one rivet 151. For this purpose, the rivet 151 is mounted in a hole made in a side wall 123 of the cooking container. If desired, several rivets 151 may be used to secure the gripping member 150 to the cooking vessel 124. Preferably, between two and four rivets 151 are used to secure the gripping member 150 to the cooking vessel 124. Alternatively, the gripping member 150 could be secured to the side wall 123 by welding or by screwing onto a stud welded to the side wall 123.If desired, another gripping member can be fixed to the side wall 123 of the cooking container 124 by means of at least one other rivet, by welding or by screwing onto a stud welded to the side wall 123.

[0064] [Fig. 6] illustrates an electrical cooking appliance 160 comprising a metal cooking support 100 associated with an induction heating zone 170. The metal cooking support 100 forming the cooking container 124 is arranged in a heating base 175 comprising the induction heating zone 170. The bottom 122 rests on the induction heating zone 170. If desired, the cooking container 124 may comprise at least one gripping member 155. In the exemplary embodiment illustrated in [Fig. 6] the cooking container 124 comprises two opposite gripping members 155. The or each gripping member 155 is fixed to the cooking container 124 by at least one rivet 156. For this purpose, the rivet 156 is mounted in a hole made in the side wall 123. If desired, several rivets 156 can be used to fix the or each gripping member 155 on the cooking container 124. Preferably between two and four rivets 156 are used to fix the or each gripping member 155 on the cooking container 124. Alternatively the or at least one of the gripping members 155 could be fixed on the side wall 123 by welding or by screwing onto a stud welded on the side wall 123.

[0065] As a variant, the metal cooking support 10 does not necessarily include a non-stick coating 1 forming a cooking surface 14 of the cooking face 11, and a protective coating 5 forming a heating surface 15 of the heating face 12.

[0066] Various modifications and / or improvements obvious to those skilled in the art may be made to the exemplary embodiments of the invention described in the present description without departing from the scope of the invention defined by the appended claims.

Claims

Claims

1. A metal cooking support (10) compatible with induction heating, having a cooking face (11) and a heating face (12), comprising a metal substrate (2) made of aluminum or aluminum alloy, and an expanded metal insert (3) made of ferritic stainless steel, said expanded metal insert (3) being inserted at least partially into the metal substrate (2) on the side of the heating face (12), characterized in that the expanded metal insert (3) has a strand thickness (EB) of between 0.45 and 1 mm, preferably of between 0.5 and 0.6 mm, and a front transparency of less than or equal to 50%, preferably less than or equal to 40%, more preferably less than or equal to 30%.

2. Metal cooking support (10) according to claim 1, characterized in that the expanded metal insert (3) has a strand width (LB) of between 0.5 mm and 1 mm.

3. Metal cooking support (10) according to one of claims 1 or 2, characterized in that the expanded metal insert (3) has an inter-strand opening diameter (OB) less than or equal to 2.3 mm, preferably less than or equal to 1.8 mm, more preferably less than or equal to 1.1 mm.

4. Metal cooking support (10) according to one of claims 1 to 3, characterized in that the metal substrate (2) has a substrate thickness (ES) less than or equal to 3.4 mm, preferably less than or equal to 3 mm, more preferably less than or equal to 2.5 mm.

5. Metal cooking support (10) according to one of claims 1 to 4, characterized in that the expanded metal insert (3) is made of type 430 stainless steel.

6. Metal cooking support (10) according to one of claims 1 to 5, characterized in that the strand thickness (EB) is 0.6 mm.

7. Metal cooking support (10) according to one of claims 1 to 6, characterized in that the strand width (LB) is 1 mm.

8. Metal cooking support (10) according to one of claims 1 to 7, characterized in that the inter-strand opening diameter (OB) is 1 mm.

9. Metal cooking support (10) according to one of claims 1 to 8, characterized in that it has a base (13) configured to rest on an induction heating device.

10. Metal cooking support (10) according to claim 9, characterized in that the bottom (13) is flat.

11. A metal cooking support (10) according to one of claims 9 or 10, characterized in that a side wall (16) rises around the bottom (13) to form a cooking container (20).

12. Metal cooking support (10) according to one of claims 1 to 11, characterized in that the metal substrate (2) carries a non-stick coating (1) forming a cooking surface (14) of the cooking face (11).

13. Metal cooking support (10) according to one of claims 1 to 12, characterized in that the metal substrate (2) and the expanded metal insert (3) carry a protective coating (5) forming a heating surface (15) of the heating face (12).

14. Culinary article (140) comprising a metal cooking support (100) and a gripping member (150) mounted on the metal cooking support (100), characterized in that the metal cooking support (100) conforms to one of claims 1 to 13.

15. Electrical cooking appliance (160) comprising a metal cooking support (100) associated with an induction heating zone (170), characterized in that the metal cooking support (100) conforms to one of claims 1 to 13.

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