HEATING SYSTEM AND COOKING APPLIANCE WITH THE SAME

Description

TECHNICAL FIELD OF THE INVENTION

[0001] The invention relates to a hob-type heating system intended, in particular, for cooking appliances. STATE OF PRIOR ART

[0002] Currently, there are professional electric cooking appliances that allow food to be cooked directly on a hob, generally made of stainless steel or chrome, without using a frying pan or saucepan. The food cooked in this way is meat, fish, or vegetables. Such a device is known, for example, from US 5,413,032.

[0003] These hobs operate using shielded heating resistors. These are mounted just below the hob. These resistors have the disadvantage of having a long temperature rise time due to the envelope present around the resistive film, as well as a small contact surface allowing heat exchange with the hob and a high thermal inertia. These heating resistors are composed of a heating resistive film made of nickel-chromium alloy centered in a tube (made of copper, stainless steel, incoloy or inconel) filled with an insulating material (magnesium oxide) ensuring heat transfer and electrical insulation.

[0004] Furthermore, the temperature regulation and distribution of these cooking plates are not optimized. STATEMENT OF THE INVENTION

[0005] An aim of the invention is to provide an optimized hob type heating system with low thermal inertia allowing a rapid rise in temperature while having optimal temperature distribution and regulation.

[0006] To this end, according to the invention, there is provided a heating system comprising a cooking plate having a lower surface, heating means positioned under the cooking plate opposite the lower surface, characterized in that the heating means comprise a heat diffuser resting on the lower surface of the cooking plate and extending opposite the latter in a complementary manner, and a heating element resting on a lower face of the heat diffuser and extending opposite a part of the lower face of the heat diffuser.

[0007] Advantageously, but optionally, the heating system according to the invention has at least one of the following technical characteristics: the cooking plate is a thin plate having a small thickness; the cooking plate is made of refractory material; the heat diffuser is made of a thermally conductive material, in particular aluminum or copper; the heating element comprises a flat resistive film; the heating element comprises a support plate on which the flat resistive film extends; the heating system further comprises means for holding the plate, the heat diffuser, and the heating element in position; the heating means comprise a series of heating elements distributed over the lower face of the heat diffuser; and, the heating means further comprise a thermal sensor associated with the heating element.

[0008] Also provided according to the invention is a cooking appliance intended for the direct cooking of food comprising a heating system having at least one of the preceding technical characteristics. BRIEF DESCRIPTION OF THE FIGURES

[0009] Other characteristics and advantages of the invention will emerge from reading the following description of an embodiment of the invention. In the attached drawings: there Figure 1 is a three-dimensional view of a heating system according to the invention; Fig. 2 is a bottom view of the heating system of the Figure 1 ; there Figure 3 is a side view of the heating system of the Figure 1 ; there Figure 4 is an exploded three-dimensional view of the heating system of the figures 1 to 3 ; there Figure 5 is a three-dimensional view of a heating element of the heating system according to the invention.

[0010] For clarity, identical or similar elements are identified by identical reference signs throughout the figures. DETAILED DESCRIPTION OF AN EMBODIMENT

[0011] In reference to the figures 1 to 4 , we will describe a heating system 1 according to the invention.

[0012] The heating system 1 according to the invention comprises a stack formed of a cooking plate 10, a heat diffuser 20, one or more heating elements 30. The heat diffuser 20 and the heating element(s) 30 are part of the heating means of the heating system 1 according to the invention. Furthermore, the heating system 1 according to the invention comprises means 12, 50 for holding the stack thus formed in position.

[0013] The cooking plate 10 is here a rectangular cooking plate. The cooking plate 10 comprises an upper cooking surface 13 intended to directly receive food to be cooked such as meat, fish or vegetables. The cooking plate 10 has a lower surface 14. In one embodiment, the cooking plate 10 is a thin plate having a small thickness. The cooking plate 10 is made of a refractory material. For example, the cooking plate is made of refractory stainless steel.

[0014] Projecting from the lower surface 14, the cooking plate 10 comprises a first series of studs 11 distributed over the lower surface 14. This first series of studs 11 allows the heating system 1 according to the invention to be mounted on a cooking appliance (not shown). For example, the studs 11 are threaded rods welded onto the lower surface 14 of the cooking plate 10. The studs 11 are made of stainless steel. Here, in the figures, the series of studs 11 comprises twenty studs 11. Other numbers and distributions of these studs are possible depending on the configuration of the heating system 1 according to the invention.

[0015] Similarly, the cooking plate 10 comprises a second series of studs 12 forming part of the means for holding in position 12, 50 the stack formed of the cooking plate 10, the heat diffuser 20 and the heating element(s) 30, the second series of studs 12 extends projecting from the lower surface 14 of the cooking plate 10. As for the first series, the studs of the second series of studs 12 are, for example, added threaded rods welded to the lower surface 14. The studs of the second series of studs 12 are made of copper for example. Here, in the figures, the series of studs 12 comprises forty-eight studs. Other numbers and distributions of these studs are possible depending on the configuration of the heating system 1 according to the invention, in particular depending on the number of heating elements 30 installed.It should be noted that the second series of studs 12 receives, once said stack has been formed, clamping means 50, which are here nuts which screw onto the studs. These nuts 50 can be made of brass for example.

[0016] The heat diffuser 20 is here a rectangular-shaped plate. The heat diffuser has an upper face 23 and a lower face 24. It further comprises, here, a peripheral rim 25 which projects from the lower face 24. Furthermore, the heat diffuser 20 has a first series of through-holes 21 whose number and positioning correspond to the number and positions of studs 11 that the series of through-holes 21 is intended to receive during an assembly of the heating system 1 according to the invention. Furthermore, the heat diffuser 20 has a second series of through-holes 22 whose number and positioning correspond to the number and positions of studs of the second series of studs 12 that the series of through-holes 22 is intended to receive during an assembly of the heating system 1 according to the invention.Thus, once assembled, the heat diffuser 20 extends opposite the lower surface 14 of the cooking plate 10 and the upper face 23 comes to bear on the lower surface 14 of the cooking plate 10. In addition, the heat diffuser 20 has a shape complementary to the latter so as to cover a maximum surface of the latter. This makes it possible to obtain an optimal heat exchange surface between the heating means and the cooking plates 10.

[0017] The rim 25 makes it possible to protect the heating element(s) 30 which are positioned resting against the lower face 24 of the thermal diffuser 20 and which we will now describe.

[0018] In reference to the Figure 5, the heating element 30 comprises a support plate 34 on which a flat resistive film 33 extends. The flat shape of the flat resistive film 33 makes it possible to have a large heat exchange surface. At each end of the flat resistive film 33, the latter comprises an electrical connection terminal 31. Here, the flat resistive film 33 is U-shaped. On the other hand, the heating element 30 comprises, here, three flat resistive films 33 which are mounted in parallel with each other. It should be noted that the number and shape of the flat resistive films 33 may be different depending on the configuration of the heating element 30 as well as the desired heating regulation.

[0019] The support plate 34 further comprises a series of through-holes 32, here eight in number. These through-holes 32 are configured so as to receive, during assembly of the heating system 1 according to the invention, all or part of the studs of the second series of studs 12. Thus, once assembled, the heating element 30 extends opposite the lower surface 24 of the heat diffuser 20 and comes to bear on said lower surface 24 of the heat diffuser 20.

[0020] As illustrated here in the figures, the heating system 1 according to the invention comprises a series of six heating elements 30 distributed on the lower face 24 of the heat diffuser 20. Again, the number and position of the heating elements 30 depend on the desired configuration of the heating system 1 according to the invention. Having several heating elements 30 makes it possible to simply and easily create different cooking zones at the upper cooking surface 13 of the cooking plate 10. The maximum number of these cooking zones is equal to the number of heating elements 30 installed. Indeed, with such a structure, it is possible to supply the heating elements present 30 differently and independently of each other. In addition, thermal sensors 40 are provided: there is a thermal sensor 40 associated with each of the heating elements 30.This makes it possible to control the temperature of each of the heating elements 30 independently and therefore the cooking temperature of the associated cooking zone. The thermal sensor 40 is for example a thermocouple which is brazed and insulated on one of the studs of the second series of studs 12 passing through the support plate 34 of the associated heating element 30.

[0021] Such a heating system 1 according to the invention is intended to be mounted on a cooking appliance which further comprises a unit for controlling and supplying the heating elements 30 connected, on the one hand, to the supply terminals 31 of the heating elements 30 and, on the other hand, to the thermal sensors 40.

[0022] The use of a heating system 1 according to the invention makes it possible to obtain rapid temperature increases due to its low thermal inertia while having independent multi-point or multi-zone regulation of the heating (and therefore cooking) temperature. In addition, such a heating system 1 according to the invention makes it possible, due to its structure, to have temperature homogeneity at the level of the upper cooking surface 13 of the cooking plate 10.

[0023] This way, electrical energy consumption is controlled due to the possibility of managing several cooking zones: for example, heating only part of the cooking plate without having to heat the entire cooking plate. The efficiency of the system is thus improved.

[0024] Of course, it is possible to make many modifications to the invention without departing from its scope.

Claims

1. A heating system (1) comprising a cooking plate (10) comprising a bottom surface (14), heating means (20, 30, 40) positioned under the cooking plate facing the bottom surface, the heating means comprising a thermal diffuser (20) bearing on the bottom surface of the cooking plate and extending facing the latter in a complementary manner, characterized in that the heating means comprise a series of heating elements (30) distributed and bearing on a bottom face (24) of the thermal diffuser and extending facing a part of the bottom face of the thermal diffuser.

2. The heating system as claimed in claim 1, characterized in that the cooking plate is a thin plate having a small thickness.

3. The heating system as claimed in claim 1 or 2, characterized in that the cooking plate is made of a refractory material, notably of refractory stainless steel.

4. The heating system as claimed in one of claims 1 to 3, characterized in that the thermal diffuser is made of a thermally conductive material, notably of aluminum or copper.

5. The heating system as claimed in one of claims 1 to 4, characterized in that the heating elements comprise a flat resistive film (33).

6. The heating system as claimed in claim 5, characterized in that the heating elements comprise a support plate (34) over which the flat resistive film extends.

7. The heating system as claimed in one of claims 1 to 6, characterized in that it further comprises means (12, 50) for maintaining the position of the plate, the thermal diffuser and the heating element.

8. The heating system as claimed in one of claims 1 to 7, characterized in that the heating means further comprise a thermal sensor (40) associated with the series of heating elements.

9. The heating system as claimed in claim 8, characterized in that the heating means comprise a series of thermal sensors (40) associated with the series of heating elements, each heating element of the series of heating elements comprising a thermal sensor of the series of thermal sensors.

10. A cooking appliance intended for the direct cooking of foods, characterized in that it comprises a heating system as claimed in one of claims 1 to 9.