EP2131625A1 - N.a. - Google Patents

Abstract

The element (100) has a sensor for detecting surface temperature of a wall (1) of a cooking chamber by contacting the wall with a contact surface. The wall is heated by a heating plate (10). Holding elements (101, 102) are detachably connected with the wall by interconnecting a spring clip (110) for pressing the contact surface at the wall. The holding elements are made of thermally insulated material i.e. ceramic such as stealan, to control temperature influence from outside of the contact surface at the sensor. The contact surface is made of a stainless steel panel (103). Independent claims are also included for the following: (1) a heating plate for heating a wall of a cooking device (2) a cooking device comprising a cooking chamber.

Description

The present invention relates to a thermocouple, a heating plate with such a thermocouple and a cooking appliance with such a heating plate.

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 described in the form of a thermal 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, 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 can be brought.

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

Object of the present invention is to provide a thermocouple, 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 a thermocouple with at least one sensor for detecting a surface temperature of a heatable at least one heater wall, in particular a cooking chamber, by contacting the wall with a contact surface and a holding member which is releasably connectable to the wall with the interposition of a spring device is to press the contact surface of the sensor on the wall, and at least partially made of a thermal insulation material to reduce temperature influences from outside the contact surface on the sensor.

It is preferred that the contact surface of the sensor is substantially circular, and / or the contact surface of the sensor is provided by a metal plate, in particular stainless steel plate, and / or the contact surface of the sensor can be passed through the center of a plate-shaped heating element of the heater.

It is also proposed that the holding member is formed of a ceramic, in particular Stealan, and / or at least two, in particular releasably, interconnectable components.

It can again be provided that the first component comprises a bearing surface for the sensor, in particular the metal plate, and / or is formed like a stamp, and / or at least partially inserted into the second component.

The invention additionally proposes that the first component comprises a first, substantially cylindrical region with a first cross section and a second, essentially cylindrical region with a second cross section, which is smaller than the first cross section, wherein the first region the bearing surface and at least a recess, preferably in the form of a slot extending along the first area over the entire first area, for at least one cable of the sensor.

Embodiments of the invention can also be characterized in that the metal plate of the sensor can be contacted with two cables, wherein preferably the cables are welded on the side facing away from the contact surface of the metal plate and / or in the slot, in particular in two diametrically opposed slots, the extend at least partially into the second region of the first component, are guided by the bearing surface of the first component and at least partially between the first and second components.

With the invention it is further proposed that the second component of the holding member having two open ends and an inner diameter which is larger than the second cross section of the second region of the first component and smaller than the first cross section of the first region of the first component, sleeve-like, in particular is formed in the form of a hollow cylinder, and the first component is insertable with its second region in the second component, so that at one end of the second component, the first region of the first component is arranged and from the second end of the second component, the cable of the sensor led out.

In addition, it can be provided that the second component of the holding member provides a stop for engaging the spring device, in particular in the form of a collar, wherein preferably the hollow cylinder of the second component is formed with a radially outwardly extending circumferential enlargement in the region of the stop.

According to the invention, it is also proposed that the spring device can be attached to the wall, in particular releasably, by means of a fastening device, wherein the fastening device preferably also serves for fastening the heating element of the heating device to the wall and / or provides a screw connection.

The invention also provides a heating plate for at least partially heating the wall, in particular a cooking chamber of a cooking appliance, with a first fastening device for fastening at least one heating element to the wall and with a second fastening device for fastening at least one thermocouple according to the invention on the wall.

In this case, an embodiment may be characterized by a carrier layer which can be applied to the wall, in particular in the form of a graphite foil, on which the heating element rests on the side opposite the wall, at least in sections, directly or indirectly, and which homogenizes the heat input from the heating element the wall serves, and / or an insulating layer arranged at least in regions on the heating element on its side opposite the wall, which preferably leaves a recess free at least for a contacting device of the heating element.

Furthermore, embodiments are proposed with the invention, which are characterized by at least a first recess for passing at least a portion of the thermocouple and / or at least a second recess for passing at least a portion of the first fastening device.

Furthermore, it can be provided that the first fastening device provides at least a part of the second fastening device, and / or the second fastening device comprises the spring device.

It can also be provided that the first fastening device comprises at least two screws, preferably in each case in cooperation with a nut, and / or at least two bolts, over which, in particular each with the interposition of at least one washer, the heating element, preferably the carrier layer, the Heating element and the insulating layer, against the wall is pressed.

It is proposed that the spring means for pressing the contact surface of the sensor of the thermocouple against the wall via the screws and / or bolts can be attached.

According to the invention it can also be provided that the heating plate has a substantially rectangular circumference, wherein preferably the rectangle of the heating plate is divisible into four equal rectangular sections, in each of these sections a screw or bolt of the first fastening device is arranged and the spring means between two arranged on a diagonal of the rectangle of the heating plate screws or bolts, connected to the latter, is arranged to hold the thermocouple in the center of the rectangle of the heating plate.

Embodiments of the invention may also be characterized in that the spring device comprises at least one spring clip or leaf spring having at its first end a first first region for engaging the first fastening device and at its second end a second first region for engaging the first fastening device wherein in each case in the first and second first region in each case a first hole for passing a screw or a bolt is provided and / or the first and second first region each represents a flat pressing region.

Furthermore, it can be provided that the thermocouple in a second region of the spring clamp or leaf spring, which is preferably arranged substantially centrally between the first and second first region, is connectable to the spring clamp or leaf spring, preferably by attachment in a second hole.

According to the invention, it can again be provided that the second hole has a double hole with a first section, which has an inner diameter which corresponds at least to the outer diameter of the collar of the second component of the retaining member, and a second section, which has an inner diameter which is smaller than that Outer diameter of the collar and at least as large as the outer diameter of the hollow cylinder of the second component is included.

Special embodiments of the invention may be further characterized in that the second region of the spring clip or leaf spring adjacent to the second portion of the second hole is a flat pressure region, wherein the spring clip or leaf spring preferably between two adjacent planar Andrückbereichen substantially V-shaped, in particular away from the heating element.

Finally, the invention also provides a cooking appliance with a cooking chamber, in particular in the form of a crucible, comprising at least one wall, in particular a crucible bottom, with at least one heating plate according to the invention, and with a control or regulating device for adjusting the heating power of the heating plate, with the Heating plate, in particular via the contacting device and with a thermocouple according to the invention, in particular its cable, is connectable.

The invention is based on the surprising finding that a contact surface of a sensor of a thermocouple with a wall whose surface temperature is to be measured, in particular completely by contacting a defined contact force, can be contacted, and lateral temperature influences on the sensor, in particular by thermal radiation of a wall heating element, as well as thermal bridges, as between the sensor and a thermocouple on 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, preferably via a fastening device of the Heating element is attachable to the wall. For attachment of the thermocouple to the spring clip or leaf spring, the latter preferably has a double hole, a first, larger portion of the double hole serving to insert the thermocouple and a second smaller portion 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 erfindungsgemäßen Heizplatte und einem erfindungsgemäßen Thermoelement;

Figur 2

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

Figur 3

eine Seitenansicht des erfindungsgemäßen 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 heating plate according to the invention and a thermocouple according to the invention;

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 the invention 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 pot, as he for example under the trade name VarioCookingCenter® is available, a crucible bottom 1, on which a heating plate 10 according to the invention is mounted with a thermocouple 100 according to the invention 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 arranged on two opposite sides of the heating plate 10, which in turn has a substantially rectangular periphery, on a center line of the rectangle of the heating plate 10th

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 rests on an end of the sleeve 101. 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 112a. In the second pressing portion 111 a, a portion 110 a 2 of a second hole or

Double hole 110 a 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.

LIST OF REFERENCE NUMBERS

1

crucible bottom

10

heating plate

10a, 10b

recess

11

graphite foil

12

heating element

13

insulation layer

13a

recess

14

washer

15

screw

16

mother

17

washer

18

contact element

19a, 19b, 19c

washer

20

mother

21

screw

100

thermocouple

101

shell

101

collar

101b

hollow cylinder

102

stamp

102a1

head

102a2

stalk

102b

slot

103

stainless steel plate

104a-104c

electric wire

110

spring clip

110a, 110b1, 110b2

hole

110a1, 110a2

hole section

111 al-111b22

pressing area

112a1 - 112b22

bending edge

Claims (21)

Thermocouple (100)
with at least one sensor (103) for detecting a surface temperature of a wall (1) which can be heated via at least one heating device (10), in particular a cooking chamber, by contacting the wall (1) with a contact surface and
with a holding member (101, 102) detachably connectable to the wall (1) with interposition of a spring means (110) for pressing the contact surface of the sensor (103) against the wall (1) and at least partially from a thermal Insulating material is made to reduce temperature influences from outside the contact surface on the sensor (103). Thermocouple according to claim 1, characterized in that
the contact surface of the sensor (103) is substantially circular,
and or
the contact surface of the sensor is provided by a metal plate, in particular stainless steel plate (103), and / or
the contact surface of the sensor (103) can be passed through the center of a plate-shaped heating element (12) of the heating device (10). Thermocouple according to claim 1 or 2, characterized in that
the holding member of a ceramic, in particular Stealan, and / or at least two, in particular releasably, interconnectable components (101, 202) is formed. Thermocouple according to claim 3, characterized in that
the first component (102) comprises a bearing surface for the sensor (103), in particular the metal plate, and / or is formed like a stamp, and / or at least partially insertable into the second component (103). Thermocouple according to claim 4, characterized in that
the first component (102) comprises a first substantially cylindrical portion (102a1) having a first cross section and a second substantially cylindrical portion (102a2) having a second cross section which is smaller than the first cross section, the first portion (102a1) has the support surface and at least one recess, preferably in the form of a slot (102b) extending over the entire first region along the first region (102a1), for at least one cable (104a) of the sensor (103). Thermocouple according to claim 5, characterized in that
the metal plate of the sensor (103) can be contacted with two cables (104a), wherein preferably the cables (104a) are welded on the side of the metal plate facing away from the contact surface and / or in the slot (102b), in particular in two diametrically opposite slots, which at least partially extend into the second region (102a2) of the first component (102), are guided by the bearing surface of the first component (102) and initially partially between the first and second component (102, 101). Thermocouple according to claim 5 or 6, characterized in that
the second component (101) of the retaining member having two open ends and an inner diameter larger than the second cross section of the second region (102a2) the first component (102) and smaller than the first cross section of the first region (102a1) of the first component (102), sleeve-like, in particular in the form of a hollow cylinder (101b) is formed, and the first component (102) with its second region (102a2) in the second component (101) is insertable, so that at one end of the second component (101) of the first region (102a1) of the first component (102) is arranged and from the second end of the second component (101) Cable (104b) of the sensor (103) are led out. Thermocouple according to one of claims 3 to 7, characterized in that
the second component (101) of the holding member provides a stop for engaging the spring means (110), in particular in the form of a collar (101a), preferably the hollow cylinder (101b) of the second component (101) having a radially outwardly extending circumferential enlargement Area of the stop is formed. Thermocouple according to one of the preceding claims, characterized in that
the spring device (110) can be attached to the wall (1), in particular releasably, by a fastening device (14-17), wherein the fastening device preferably also serves to fasten the heating element (12) of the heating device (10) to the wall (1) and / or provides a screw connection. Heating plate (10) for at least partially heating a wall (1), in particular a cooking chamber of a cooking appliance,
with a first fastening device (14-17) for fastening at least one heating element (12) to the wall (1) and
with a second fastening device (14-17, 110) for fastening at least one thermoelement (100) according to one of the preceding claims to the wall (1). Heating plate according to claim 10, characterized by
a carrier layer, which can be applied to the wall (1), in particular in the form of a graphite foil (11), on which, on the wall (1) opposite side, at least in sections, directly or indirectly, the heating element (12) rests and the equalization of Heat input from the heating element (12) in the wall (1) is used, and / or
an insulating layer (13) arranged at least in regions on the heating element (12) on its side opposite to the wall (1), which preferably leaves free a recess (13a) at least for a contacting device (18) of the heating element (12). Heating plate according to claim 10 or 11, characterized by
at least one first recess (10b) for passing at least a part of the thermocouple (100) and / or
at least one second recess (10a) for passing at least a part of the first fastening means (14-17). Heating plate according to one of claims 10 to 12, characterized in that
the first fastening device (14-17) provides at least part of the second fastening device (14-17, 110), and / or the second fastening device (14-17, 110) comprises the spring device (110). Heating plate according to claim 13, characterized in that
the first fastening device comprises at least two screws (15), preferably each in cooperation with a nut (17), and / or at least two bolts, via which, in particular in each case with the interposition of at least one washer (14, 16), the heating element (12 ), preferably the carrier layer (11), the heating element (12) and the insulating layer (13), against the wall (1) is pressed. Heating plate according to claim 14, characterized in that
the spring means (110) for pressing the contact surface of the sensor (103) of the thermocouple (100) against the wall (1) via the screws (15) and / or bolts is attachable. Heating plate according to one of claims 10 to 15, characterized in that
the heating plate (10) has a substantially rectangular circumference, wherein preferably the rectangle of the heating plate (10) can be divided into four equally sized rectangular sections, in each of these sections a screw (15) or a bolt of the first fastening device (14-17) and the spring means (110) is disposed between two screws (15) or bolts disposed on a diagonal of the rectangle of the heating plate (10), connected to the latter, around the thermocouple (100) in the center of the rectangle of the heating plate (10) hold. Heating plate according to one of claims 10 to 16, characterized in that
the spring means comprises at least one spring clip or leaf spring (110) having at its first end a first first region (111b1) for engaging the first attachment means (14-17) and at its second end a second first region (111b2) for engaging the first one Fastening device (14-17), wherein preferably in the first and second first region (111b1, 111b2) respectively a first hole (110b1, 110b2) for passing a screw (15) or a bolt is provided and / or the first and second first portion 111b1), 111b2) one each level pressing area represents. Heating plate according to claim 17, characterized in that
the thermocouple (100) is connectable to the spring clip or leaf spring (110) in a second region (111a) of the spring clip or leaf spring (110), which is preferably located substantially centrally between the first and second first regions (111b1, 111b2) , preferably by attachment in a second hole (110a). Heating plate according to claim 18, characterized in that
the second hole (110a) has a double hole having a first portion (110a1) having an inner diameter at least equal to the outer diameter of the collar (101a) of the second component (101) of the support member, and a second portion (110a2) having a first portion Inner diameter which is smaller than the outer diameter of the collar (101 a) and at least as large as the outer diameter of the hollow cylinder (101 b) of the second component (101) comprises. Heating plate according to claim 19, characterized in that
the second portion (111a) of the spring clip or leaf spring (110) adjacent the second portion (110a2) of the second hole (110a) constitutes a flat pressing portion, the spring clip or leaf spring (110) preferably being sandwiched between two adjacent planar pressing portions (111a-111b2) ) substantially V-shaped, in particular away from the heating element (12). Cooking appliance
with a cooking chamber, in particular in the form of a crucible, which comprises at least one wall, in particular a crucible bottom (1), with at least one heating plate (10) according to one of claims 10 to 20, and
with a control or regulating device for adjusting the heating power of the heating plate (10), with the heating plate (10), in particular via the contacting device (18), and with at least one thermoelement (100) according to any one of claims 1 to 9, in particular via the cable (104b), is connectable.

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