EP2131625B1 - Cooking device with a cooking plate with a thermocouple element - Google Patents

Description

The present invention relates to a cooking appliance.

Thermocouples, each as part of a control or regulating circuit of a heating device for heating a container wall, are well known in the art. For example, the EP 1 722 661 B1 a device for heating liquids, in particular milk, in a container connected to a heating element which, over time, provides variable power output as a function of the temperature reaching the liquid, the heating element being adapted to close the bottom of the container Heat and reduce the supply current over time with increasing temperature of the liquid. Between the heating element and the container, a thermal diffusion element is provided to distribute the heat generated by the heating element. Moreover, in the EP 1 722 661 B1 a thermocouple in the form of a heat sensor, which is connected to the heating element to separate it when a certain temperature is reached. For this purpose, the thermal sensor is in contact with the container through an opening in the thermal diffusion element.

Also in itself heating plates are well known in the art, in which case in particular the WO 2005/032214 A2 to indicate. There, the construction of a heating plate, which is releasably attached to a cooking appliance, preferably the bottom of a crucible, fastened disclosed. More specifically, a heating plate for a cooking appliance, in particular for direct or indirect heating of at least one item to be cooked, described, the at least one carrier layer, at least one at least partially directly or indirectly adjacent to the carrier layer Heizelementschicht, at least one electrical contact or conductor element and at least one resilient locking element, which is connected or connectable to the electrical contact or conductor element comprises, wherein the electrical contact or conductor element via the spring force of the resilient locking element at least temporarily in contact with at least one heating resistor and / or at least one contact point of the heating element layer brought is.

From the US 4,241,289 A For example, a thermocouple is known to provide an electrical signal representative of a device temperature on a surface, wherein the thermocouple is operably engageable with the surface by a biasing spring.

The DE 1 141 395 B describes a temperature sensor containing a temperature-dependent temperature sensor, which serves to obtain a temperature-dependent current and for the automatic control of the temperature of an electric heating device, wherein the sensor is separated from the body to be sensed by a thin thermal insulation.

From the EP 0 021 107 A1 a heating element for a cooking unit with a temperature sensor in the edge region of a heating unit is known, wherein a heat transfer element covers a part of the edge region of the heating element and acts on a projecting out of this outer portion of the heat transfer element arranged outside the heating element temperature sensor.

The US 2,727,974 A describes an electric heater with an arrangement for controlling and regulating the average electrical energy.

The WO 2006/082383 A1 discloses an electrical heating device with a temperature sensor device, wherein the temperature sensor device comprises a temperature-sensitive electrical element, such as a thermocouple, a thermistor or a temperature-dependent resistor, and that the temperature measuring device is contactable via a spring bias.

Cooking appliances are also basically known in the prior art in various embodiments. Thus, in particular, cooking bars, such as those sold under the trade name Va-rioCookingCenter®, with a heating plate for heating a crucible bottom are known in the prior art.

Object of the present invention is to provide a cooking appliance, with which the surface temperature of a wall of a cooking chamber, in particular a crucible bottom, can be detected with high accuracy.

This object is achieved by the features of claim 1.

Advantageous developments are described in claims 2 to 19.

The invention is based on the surprising finding that in a cooking appliance, a contact surface of a sensor of a thermocouple with a wall, the surface temperature is measured, in particular by applying a defined contact force completely, contactable, and lateral temperature influences on the sensor, in particular by thermal radiation of a heating element heating the wall, as well as thermal bridges, as between the sensor and a thermocouple to the wall holding fastener, can be substantially avoided by arranging the sensor on a holding member having a poor thermal conductivity, ie from a thermal insulation material, so that the Surface temperature of the wall can be measured with high accuracy. The thermoelement according to the invention thus has a defined contact surface for contacting said wall. The holding member of the thermocouple also presses the sensor under spring tension on the wall in the manner of a punch.

Preferably, the holding member is formed in two parts, with a partially insertable into a sleeve stamp, which carries the sensor in the form of a metal plate on his stamp head. Two cables may be welded to the metal plate, on the side opposite the contact surface of the metal plate. The cables can also be separated from each other to avoid multiple measurement points are first performed in slots of the stamp head and then between the stem of the punch and the sleeve. So the cables can also hold the sleeve on the stamp.

To press the sensor under spring tension on the wall, a spring clamp or leaf spring can be used, which is preferably attachable via a fastening device of the heating element on the wall. To attach the thermocouple to the spring clamp or leaf spring, the latter preferably has a double hole, wherein a first, larger portion of the double hole the insertion of the thermocouple and a second smaller portion serves to clamp the thermocouple by engaging a collar of the sleeve.

Figur 1

eine Teilschnittansicht durch ein erfindungsgemäßes Gargerät im Bereich eines Tiegelbodens mit einer Heizplatte und einem Thermoelement;

Figur 2

eine perspektivische Ansicht des Tiegelbodens samt Heizplatte und Thermoelement von Figur 1;

Figur 3

eine Seitenansicht des Thermoelements der Figuren 1 und 2;

Figur 4

eine Seitenansicht einer Komponente des Thermoelements von Figur 3; und

Figur 5

eine perspektivische Ansicht einer Federklemme zur Fixierung des Thermoelements gemäß den Figuren 1 bis 4.

Further features and advantages of the invention will become apparent from the following description in which an embodiment of the invention by way of example with reference to schematic drawings is explained in detail. Showing:

FIG. 1

a partial sectional view through an inventive cooking appliance in the region of a crucible bottom with a hot plate and a thermocouple;

FIG. 2

a perspective view of the crucible bottom, including heating plate and thermocouple of FIG. 1 ;

FIG. 3

a side view of the thermocouple of FIGS. 1 and 2 ;

FIG. 4

a side view of a component of the thermocouple of FIG. 3 ; and

FIG. 5

a perspective view of a spring clip for fixing the thermocouple according to the FIGS. 1 to 4 ,

As FIG. 1 can be removed, has a cooking appliance according to the invention, which may be a garden bar, as it is available, for example, under the trade name VarioCookingCenter®, a crucible bottom 1, to which a heating plate 10 is attached with a thermocouple 100, on.

The heating plate 10 in turn comprises a graphite foil 11 as a carrier layer and heat diffusion layer on the crucible bottom 1, a heating element 12 on the side remote from the crucible bottom 1 side of the graphite foil 11 and an insulating layer 13 on the side facing away from the graphite foil 11 of the heating element 12. The insulating layer 13 has two recesses 13a for two contact elements 18, see FIG. 2 in which current can be applied to the heating element 12 via the contact elements 18 via a current source (not shown) as a function of output data of a control device (not shown) connected to the thermocouple 100. The contact elements 18 are each attached via a screw connection to the crucible bottom 1, wherein each screw has a screw 21, a nut 20 and washers 19a to 19c. The contact elements 18 are on two opposite sides of the heating plate 10, the in turn, has a substantially rectangular circumference, arranged on a center line of the rectangle of the heating plate 10.

The heating plate 10 is in turn attached via a fastening device to the crucible bottom 1, which is a screw connection with four screws 15, in each case in operative connection with a nut 17 and two washers 14, 16. The rectangle of the heating plate 10 is divided into four rectangular sections, in each of which a screw 15 extends centrally, so as to achieve a uniform pressure of the heating plate 10 on the crucible bottom 1. To further even out the pressure of the heating plate 10 on the crucible bottom 1, at least one of the washers is formed enlarged, namely, the washer 14 is provided with a circular circumference extending over a majority of the respective rectangular portion of the rectangle of the heating plate 10, as shown in FIG FIG. 2 shown.

The thermocouple 100 is located centrally within the heating plate 10, equidistant from each of the four screws 15, as well as best in FIG FIG. 2 you can see.

The thermocouple 100 consists of a sleeve 101, a punch 102, a stainless steel plate 103 and cables 104a, 104b, see Figures 3 and 4 , More precisely, the stainless steel plate 103, which is essentially circular in plan view and represents the actual sensor, is arranged on a resting surface of a head 102a1 of the punch 102. The stainless steel plate 103 has on its side opposite the support surface of the head 102a1 side a contact surface for contacting the crucible bottom 1, as in FIG. 1 is shown on. On the stainless steel plate 103, two cables 104a are further welded on the side facing the support surface, which, isolated with PTFE, in regions 102b of the punch 102 are partially guided. After leaving the slots 102b, the cables 104b are further insulated and protected by a sheath of silicone and extend between a stem 102a2 of the punch 102 and the sleeve 101 to finally exit the sleeve 101, see FIG. 3 , The cables 104a, 104b thus also serve to hold the sleeve 101 on the punch 102, namely in the region of the stem 102a2, which has a significantly smaller cross-section than the head 102a1 of the punch 102.

The stamp 102 together with stainless steel plate 103 and cables 104a is in FIG. 3 to see introduced into the sleeve 101. Accordingly, the head 102a1 of the punch 102 is located on one end of the Sleeve 101 on. The sleeve 101 is formed substantially hollow cylindrical, thus has a hollow cylinder 101b, with an inner diameter which is smaller than the outer diameter of the head 102a1 of the punch 102, but large enough for the harboring of the stem 102a2 of the punch 102 together with cable 104a. In addition, the sleeve 101 has an area with an enlarged diameter, which is referred to below collar 101 a.

The thermocouple 100 is fixed via a spring clip 110 relative to the crucible bottom 1, as in FIG. 1 shown. The heating plate 10 has for this purpose in addition to recesses 10a for the screws 15 a recess 10b for the thermocouple 100, so that the stainless steel plate 103 can contact the crucible bottom 1 with a defined contact surface. The spring clip 110 presses against the collar 101a of the sleeve 101 and thus ensures a defined contact pressure, while the design of the sleeve 101 and the ceramic stamp 102 ensures that lateral temperature influences on the thermocouple 100 by the heating plate 10 are negligible , In addition, the sleeve 101 and the punch 102, due to their poor heat conduction, ensure that substantially no thermal bridges can roll over the spring clip 110 to the stainless steel plate 103.

The spring clip 110 is in FIG. 5 presented in detail and then includes seven subareas. Of these seven subregions, three are substantially planar and constitute pressure regions 111a, 111b1, 111b2, which are connected via bending edges 112a1 to 112b22 with prestressed, further subregions, two of which are substantially V-shaped in FIG. 5 extend upwards. At its two ends, the spring clip 110 thus has a respective pressure region 111b1, 111b2 with a hole 110b for fixing between washers 14 and 17 of the fastening device with nuts 15 tightened on the corresponding screws 15, see FIG. 1 , A partial region extending away from the heating plate 10 adjoins these first pressing regions 111b1, 111b2 via a bending edge 112b11, 112b12, to which, after another bending edge 112b21, 111b22, another subregion adjoins, which is inclined again to the heating plate 10 , The two subregions inclined to the heating plate adjoin via bend edges 112a2 and 112a1 to a second, flat pressure region 111a. In the second pressing portion 111a is a Section 110a2 of a second hole or double hole 110a arranged in which the thermocouple 100 in FIG. 1 is shown fixed.

For fixing the thermocouple 100 in the hole portion 110a2, the thermocouple 100, with its stainless steel plate 103 at first, is to be inserted into a first portion 110a1 of the second hole 110a until the collar 101a has passed through the first hole portion 110a1 of the spring clip 110. Then, the thermocouple 100 can be shifted into the second hole portion 110a2, so that the spring clip 110 rests on the collar 101a in the second pressing portion 111b, see FIG FIG. 1 , The spring clip 110 may be preassembled with either the thermocouple 100 and then secured between the washers 14 and 17. Alternatively, the spring clip 110 may be preassembled between the washers 14 and 17, but not clamped tightly, so that then the thermocouple 100 is connectable to the spring clip 110, and then by tightening the nuts 16 on the respective screws 15, the spring clip 110 firmly can be clamped.

The inventive thermocouple 100 has a low mass of the individual components and is easy to assemble to measure with high accuracy, the surface temperature of the crucible bottom 1, so that on the crucible bottom 1, on the heating plate 10 side facing away, arranged, not shown Gargut, such as scrambled eggs or the like, on the crucible bottom 1 is uniformly heated.

The features disclosed in the foregoing description, the claims and the drawings may be essential both individually and in any combination for the realization of the invention in its various embodiments.

Claims (19)

1. A cooking device with a cooking chamber in the shape of a crucible, said cooking chamber comprising at least one wall (1) with at least one cooking plate (10) for heating the wall (1), at least in sections, wherein
   the cooking plate (10) has a first attachment means (14-17) for attaching at least one heating element (12) to the wall (1) and a second attachment means (14-17, 110) for attaching at least one thermocouple element (100) to the wall (1) and
   the thermocouple element (100) comprises at least one sensor (103) for detecting a surface temperature of the wall (1) by contacting the wall (1) with a contact surface and a holding element (101, 102) which can be detachably connected with the wall (1) by interconnecting a spring means (110), for the purpose of pressing the contact surface of the sensor (103) to the wall (1), and which is made, at least partially, of a thermally insulating material to reduce the influence of temperatures outside the contact surface on the sensor (103),
   and the cooking device has an open-loop or closed loop control unit for adjusting the heat output of the cooking plate (10) which can be connected to the cooking plate (10) and to at least one thermocouple element (100).
2. The cooking device of claim 1, characterized in that
   the wall is formed by a crucible bottom (1),
   the open-loop or closed-loop control unit can be connected to the cooking plate (10) via its contacting means (18) and/or to the thermocouple element (100) via its cable,
   the contact surface of the sensor (103) is essentially circular, and/or
   the contact surface of the sensor is provided as a metal panel, in particular a stainless steel panel (103), and/or
   the contact surface of the sensor (103) can be led through the center of a plate-shaped heating element (12) of the heating means (10).
3. The cooking device of claim 1 or 2, characterized in that
   the holding element is made of a ceramic material, in particular stealan, and/or of at least two components (101, 102) which can be connected, in particular detachably, to each other.
4. The cooking device of claim 3, characterized in that
   the first component (102) comprises a resting surface for the sensor (103), in particular the metal panel, and/or is piston-shaped, and/or can be inserted, at least partially, into the second component (101).
5. The cooking device of claim 4, characterized in that
   the first component (102) comprises a first, essentially cylindrical-shaped, area (102a1) with a first cross-section and a second, essentially cylindrical-shaped, area (102a2) with a second cross-section which is smaller than the first cross-section,
   wherein the first area (102a1) has the resting surface and at least one recess, preferably in the shape of a slot (102b) extending longitudinally along the complete first area (102a1), for at least one cable (104a) of the sensor (103).
6. The cooking device of claim 5, characterized in that
   the metal panel of the sensor (103) can be contacted by two cables (104a),
   wherein the cables (104a) are preferably welded onto the side of the metal panel facing away from the contact surface and/or led away from the resting surface of the first component (102), and initially partially between the first and second component (102, 101), through the slot (102b), in particular through two diametrically opposed slots, which extend, at least partially, into the second area (102a2) of the first component (102).
7. The cooking device of claim 5 or 6, characterized in that
   the second component (101) of the holding element is tube-shaped, in particular in the shape of a hollow cylinder (101b), with two open ends and an inner diameter which is larger than the second cross-section of the second area (102a2) of the first component (102) and smaller than the first cross-section of the first area (102a1) of the first component (102), and the first component (102) can be inserted with its second area (102a2) into the second component (101) in such a way that the first area (102a1) of the first component (102) is arranged at one end of the second component (101) and the cables (104b) of the sensor (103) are led out of the second end of the second component (101).
8. The cooking device of any one of claims 3 to 7, characterized in that the second component (101) of the holding element provides a catch for engaging the spring means (110), in particular in the form of a flange (101a),
   wherein the hollow cylinder (101b) of the second component (101) preferably has a perimeter that enlarges outwardly in a radial direction in the area of the catch.
9. The cooking device according to any one of the preceding claims, characterized in that the spring means (110) can be attached, in particular detachably, to the wall (1) via an attachment means (14-17),
   wherein the attachment means preferably also facilitates the attachment of the heating element (12) of the heating means (10) to the wall (1) and/or provides a bolted connection.
10. The cooking device according to any one of the preceding claims, characterized by a carrier layer, in particular in the form of a graphite sheet (11), that can be applied to the wall (1), with the heating element (12) resting, at least in sections, directly or indirectly, on the side of said carrier layer which is facing away from the wall (1), said carrier layer providing for a more uniform heat input from the heating element (12) into the wall (1), and/or
    an insulation layer (13) arranged, at least in sections, on the side of the heating element (12) which is facing away from the wall (1), said insulation layer preferably having at least a notch (13a) for sustaining a contacting means (18) of the heating element (12).
11. The cooking device according to any one of the preceding claims, characterized by at least a first notch (10b) through which at least a part of the thermocouple element (100) can be led, and/or
    at least a second notch (10a) through which at least a part of the first attachment means (14-17) can be led.
12. The cooking device according to any one of the preceding claims, characterized in that the first attachment means (14-17) provides at least a part of the second attachment means (14-17, 110), and/or
    the second attachment means (14-17, 110) comprises the spring means (110).
13. The cooking device of claim 12, characterized in that
    the first attachment means comprises at least two screws (15), preferably each in cooperation with a nut (17), and/or at least two bolts, through which the heating element (12), preferably the carrier layer (11), the heating element (12) and the insulation layer (13), can be pressed against the wall (1), in particular with insertion of at least one washer (14, 16), respectively.
14. The cooking device of claim 13, characterized in that
    the spring means (110) for pressing the contact surface of the sensor (103) of the thermocouple element (100) against the wall (1) can be attached by the screws (15) and/or the bolts.
15. The cooking device according to any one of the preceding claims, characterized in that the cooking plate (10) has an essentially rectangular perimeter,
    wherein the rectangle of the cooking plate (10) can be preferably subdivided into four rectangular sections of equal size, a screw (15) or a bolt of the first attachment means (14-17) is arranged in each of said sections, and the spring means (110) is arranged between two screws (15) or bolts arranged on a diagonal of the rectangle of the cooking plate (10) and connected to said screws or bolts, in order to maintain the thermocouple element (100) in the center of the rectangle of the cooking plate (10).
16. The cooking device according to any one of the preceding claims, characterized in that the spring means comprises at least one spring clip or leaf spring (110) which has a first first area (111b1) at its first end for engaging the first attachment means (14-17) and a second first area (111b2) at its second end for engaging the first attachment means (14-17), wherein a first hole (110b1, 110b2), through which a screw (15) or a bolt can be led, is preferably provided in each of the first and second first areas (111b1, 111b2) and/or the first and second first area (111b1, 111b2) each constitute a planar contact pressure area.
17. The cooking device of claim 16, characterized in that
    the thermocouple element (100) can be connected to the spring clip or leaf spring (110), preferably by attaching it in a second hole (110a), in a second area (111a) of the spring clip or leaf spring (110) which is preferably arranged essentially centered between the first and the second first area (111b1, 111b2).
18. The cooking device of claim 17, characterized in that
    the second hole (110a) comprises a double hole with a first section (110a1) having an inner diameter which is at least equal to the outer diameter of the flange (101 a) of the second component (101) of the holding element, and with a second section (110a2) having an inner diameter which is smaller than the outer diameter of the flange (101a) and at least equal to the outer diameter of the hollow cylinder (101b) of the second component (101).
19. The cooking device of claim 18, characterized in that
    the second area (111a) of the spring clip or leaf spring (110) constitutes a planar contact pressure area adjacent to the second section (110a2) of the second hole (110a), wherein the spring clip or leaf spring (110) preferably extends essentially V-shaped, in particularly in the direction away from the heating element (12), between two adjacent planar contact pressure areas (111a-111b2).

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