Temperature controller

Abstract

A temperature controller including a housing, a temperature sensor with an expansion element which generates a movement stroke as a function of the temperature. The controller includes a switching system having a switching spring on a switching spring base, upon which there acts the expansion element. An end remote from the spring contact of the switching spring is fastened to the switching spring base, an end remote from the fastening of the switching spring of the switching spring base is held securely and immovably on the temperature controller housing, the switching spring base working together with an adjustment element. To adjust the switching point of the switching system, the switching spring base together with the switching spring can be moved relative to the expansion element and/or to the actuating element.

Claims

1. A temperature controller comprising: a temperature controller housing (5), a temperature sensor (2) with an expansion element (6) which generates a movement stroke in a direction of action (AT) as a function of temperature, a first switching system (4) having a first switching spring (19) at a first switching spring base (16) on which the expansion element (6) or an actuating element (8) moved by said expansion element acts in order to switch the first switching system (4), wherein the first switching spring base (16) has a first end (16.2) of the switching spring base (16) on a first side of the expansion element (6) or the actuating element (8) and a second end (16.1) on a second side of the expansion element (6) or an actuating element (8) and a spring contact (21) disposed on the first switching spring (19) and the first switching spring base (16) is fastened to the first switching spring (19) at a point of attachment, wherein the first switching spring base (16), at the second end (16.1) is disposed on the temperature controller housing (5) and the first switching spring base (16) interacts with an adjustment element (24), one end (24.1) of said adjustment element disposed on a region (5.1) of the temperature controller housing (5) and a second end (24.2) of said adjustment element disposed against the first switching spring base (16), and by means of which, in order to adjust a switching point of the first switching system (4), the first switching spring base (16) together with the first switching spring (19) can be moved relative to the expansion element (6) and/or to the actuating element (8) upon change of a distance between the region (5.1) of the temperature controller housing (5) and the first switching spring base (16), characterized in that the adjustment element (24) is an elongate element having a longitudinal direction (A), wherein the adjustment element (24), for adjusting in an adjustment direction (J), can be permanently deformed transverse to its longitudinal direction (A) upon change of the distance between the first end (24.1) and the second end (24.2).

2. The temperature controller according to claim 1, further comprising: a second switching system (3) controlled by the temperature sensor (2), said second switching system comprising a second switching spring (12) and a second switching base (9).

3. The temperature controller according to claim 1, characterized in that the adjustment element (24) rests with the second end (24.2) of said adjustment element (24) against a side of the first switching spring base (16), said side facing away from the first switching spring (19).

4. The temperature controller according to claim 1, characterized in that the adjustment element (24) is composed of a metallic material.

5. The temperature controller according to claim 1, characterized in that the adjustment element (24) is provided, between the first end (24.1) and a second end (24.1) of said adjustment element, a curved region (24.3) that can be deformed to change a distance between the first end (24.1) and the second end (24.2).

6. The temperature controller according to claim 5, characterized in that the curved region (24.3) can be deformed upon increasing the distance between the first end (24.1) and the second end (24.2).

7. The temperature controller according to claim 6, characterized in that the curved region (24.3) has a U or V shape.

8. The temperature controller according to claim 2, characterized in that the first switching system (4) and the second switching system (3) are arranged successively in the direction of action of the expansion element (6) in the temperature controller housing (5).

9. The temperature controller according to claim 1, characterized in that the first switching spring base (16) is provided with a predetermined bending point in the form of a tapering, wherein the tapering is provided in a region of the first switching spring base (16), which region is adjacent to the end (16.1) of the first switching spring, at which end the first switching spring base (16) is secured on the temperature controller housing (5).

10. A method for adjusting the temperature controller of claim 1, comprising the steps of: a) providing the temperature controller (1, la) according to claim 1, b) fixing said temperature controller (1, la) according to claim 1 in an adjusting device, c) moving an adjusting plunger (25) towards the adjustment element (24), d) performing a first electrical contact test using connectors (18, 23) of the first switching system (4) of the temperature controller (1, 1a), e) saving the position of the adjusting plunger (25) as soon as the electrical contact test indicates a negative signal, f) moving the adjusting plunger (25) in a direction away from the adjustment element (24), g) performing a second electrical contact test using the connectors (18, 23) of the first switching system (4) of the temperature controller (1, 1a).

11. The method according to claim 10, characterized in that after step g), the following steps are carried out: h) moving the adjusting plunger (25) towards the adjustment element (24) if the electrical contact test performed in step g) indicates a positive signal, i) performing a third electrical contact test using the connectors (18, 23) of the first switching system (4), j) saving the position of the adjusting plunger (25) as soon as the third electrical contact test performed in step i) indicates a negative signal, k) moving the adjusting plunger (25) in a direction away from the adjustment element (24), l) performing a fourth electrical contact test using the connectors (18, 23) of the switching system (4).

12. The method according to claim 11, characterized in that after step l), the steps h) to l) are repeated several times until the electrical contact test performed in step l) indicates a negative signal.

13. The method according to claim 12, characterized in that prior to step c), an adjusting platelet (26) is arranged between the actuating element (8) and the first switching spring (19).

14. The method according to claim 13, characterized in that the adjusting platelet (26) arranged between the actuating element (8) and the first switching spring (19) is removed when one of the second or fourth of the electrical contact tests using the connectors (18, 23) of the first switching system (4) indicates a negative signal.

15. The method according to claim 11, characterized in that prior to step c), an adjusting platelet (26) is arranged between the actuating element (8) and the first switching spring (19).

16. The method according to claim 15, characterized in that the adjusting platelet (26) arranged between the actuating element (8) and the first switching spring (19) is removed when any one of the electrical contact tests performed immediately after any step of moving the adjusting plunger (25) in a direction away from the adjustment element (24) and before a subsequent step of moving the adjusting plunger (25) towards the adjustment element (24), indicates a negative signal.

17. The method according to claim 12, characterized in that the adjusting platelet (26) arranged between the actuating element (8) and the first switching spring (19) is removed when any one of the electrical contact tests performed immediately after any step of moving the adjusting plunger (25) in a direction away from the adjustment element (24) and before a subsequent step of moving the adjusting plunger (25) towards the adjustment element (24), indicates a negative signal.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention is explained below in greater detail by means of exemplary embodiments in connection with the drawings. In the figures:

(2) FIG. 1 shows in a schematic illustration and a side view a temperature controller according to the invention;

(3) FIG. 2 shows in an individual illustration and in a side view a biasing or adjustment element of the temperature controller of FIG. 1;

(4) FIG. 3 shows in an enlarged partial illustration a further embodiment of the temperature controller according to the invention.

WAYS OF CARRYING OUT THE INVENTION

(5) The temperature controller generally designated by 1 in FIG. 1 is intended, for example, for use in an electric hob, e.g. in an electric glass ceramic hob and, for this purpose, comprises two electric switching systems 3 and 4 which are controlled or actuated in a temperature-independent manner via a rod-shaped temperature sensor 2. A first switching system 3 thereof, which serves, for example, as protection against overheating of the hob or the respective electric heating element, has a switching point, e.g., in the range between 500 C. and 600 C. Upon reaching this switching point, the switching system 3 interrupts the electric current flow to the heating element. The second switching system 4 serves, for example, for controlling or switching a residual heat warning indicator of the hob and has a switching point, e.g., between 50 C. and 80 C. The second switching system 4 opens only at a temperature that lies below this switching point.

(6) The temperature controller 1 comprises a temperature controller housing 5 which is made from an electrically insulating material, e.g., ceramic, at least in such sections in which electrical insulation is required. The rod-shaped temperature sensor 2 projects beyond the outside of the temperature controller housing 5. The temperature sensor 2 is formed in a known manner from a rod-shaped expansion element 6 and a tube section 7, wherein the tube section 7 encloses the rod-shaped expansion element 6 in such a manner that a relative movement of the expansion element 6 within the tube section 7 is possible. At one end, the tube section 7 is fixed on the temperature controller housing 5.

(7) At the temperature sensor's 2 other end located remote from the temperature controller housing 5, the expansion element 6 and the tube section 7 are connected to one another. The rod-shaped expansion element 6 extends into the interior of the temperature controller housing 5 and interacts there with the switching systems 3 and 4, namely via an actuating element 8 attached onto the free lower end of the expansion element 6. The materials used for the expansion element 6 and the tube section 7 are selected such that the thermal expansion coefficient of the rod-shaped expansion element 6 is significantly greater than the thermal expansion coefficient of the tube section 7.

(8) The switching system 3 is substantially composed of a switching spring base 9 formed as an elongated tongue and made from a metallic material and which, with its longitudinal extent being oriented transverse or perpendicular to an axis AT of the rod-shaped temperature sensor 2, is fixed at its ends at 10 in the temperature controller housing 5. One end of the switching spring base 9 is connected to an electrical connector 11. The switching system 3 further comprises a switching spring 12 which is arranged at that side of the switching spring base 9 that faces towards the temperature sensor 2 and extends almost over the entire length of the switching spring base 9 and is fastened with one end to the switching spring base 9 near the end thereof.

(9) The switching spring 12 has at its other end a switching or spring contact 13 which interacts with a stationary contact 14 which is provided on the temperature controller housing 5 and is connected to an electrical connector 15. The two electrical contacts 11 and 15 extending out of the temperature controller housing 5 form the connectors of the switching system 3 and, e.g., are integral part of an electrical circuit for supplying the heating element of the hob.

(10) Furthermore, the arrangement is made such that the switching spring 12 is in the normal state, i.e., in its state not actuated by the temperature sensor and in its position closing the switching system 3, in which the spring contact 13 rests against the stationary contact 14, and the switching spring 12 opens the switching system 3 only upon reaching the temperature corresponding to the switching point by moving away or displacing the spring contact 13 from the contact 14. For this purpose, the actuating element 8 acts upon the switching spring 12 in the sense of this spring approaching the spring base 9.

(11) The switching system 4 comprises a spring base 16 which, again, is made in a tongue-like or elongated manner from a metallic material with spring properties and, with its longitudinal extent, is oriented transverse or perpendicular to the axis AT. Only one end 16.1 of the spring base 16 is fixed at 17 on the temperature controller housing 5 and is connected there to a connector 18 that extends out of the temperature controller housing 5. Near the other end 16.2, which is located remote from the fastening 17, the one end of a second switching spring 19 is fastened at 20 on the spring base 16. The switching spring 19 is located at that side of the switching spring base 16 that faces away from the temperature sensor 2 and has at its free end a spring contact 21 which interacts with a fixed contact 22 which is provided on the temperature controller housing 5 and is connected to an electrical connector 23.

(12) The two connectors 18 and 23 form the connectors of the switching system 4. The latter is configured such that after adjusting the temperature controller 1 of the switching system 4, it is open in the initial state, i.e., the switching spring 19 is deflected or moved towards its switching spring base 16 by the actuating element 8 to such an extent that the spring contact 21 is spaced apart from the stationary contact 22. The switching system 4 is closed, i.e., the spring contact 21 rests against the contact 22, only at a temperature at the temperature sensor 2 that corresponds to or exceeds the switching point of the switching system 4.

(13) The rod-shaped expansion element 6 extends through the switching spring base 16 and the switching spring 19. The actuating element 8 attached onto the lower end of the expansion element 6 is located between the two switching springs 12 and 19. The latter are each composed of a material which is electrically conductive and suitable for switching springs and, in addition, are each designed for a snap-in movement or for quick opening and closing of the switching systems 3 and 4.

(14) 8.1 designates a spring which acts upon the lower end of the actuating element 8 shown in FIG. 1 and secures the actuating element 8 on the rod-shaped expansion element 6 by an axial force which acts upwards in the illustration of FIG. 1.

(15) The characteristic of the temperature controller 1 is the biasing or adjustment element 24 for the switching spring base 16 which is made in a flap- or strap-like manner from a permanently deformable material, for example metal, and which is fixed with one section or end 24.1 on a region 5.1 of the temperature controller housing 5, for example by clamping, and acts with its other section or end 24.2 on that end of the switching spring 16 that is remote from the fastening 17 and therefore adjacent to the fastening 20.

(16) In detail (see FIG. 2), the adjustment element 24 in the illustrated embodiment is configured such that it has a curved region 24.3 which is situated between its two ends 24.1 and 24. 2 and, in the illustrated embodiment, is configured to be angular or V-shaped, namely having two legs 24.3.1 and 24.3.2 enclosing an angle of at least 90, preferably an angle greater than 90 between one another, and having a section 24.3.3 that connects these legs.

(17) Due to a permanent deformation of the adjustment element 24 perpendicular to its surface sides at the region 24.3, a change of the distance between the ends 24.1 and 24.2 and therefore a displacement of the end 16.2 of the switching spring base 16 and an adjustment of the switching point of the switching system 4 in the ways as described in greater detail below is possible. In the embodiment illustrated, this adjustment is carried out upon partial reforming of the curvature of the region 24.3 by means of an adjusting plunger 25 acting on the convex side thereby increasing the distance between the ends 24.1 and 24.2, wherein the free end 16.2 of the switching spring base 16 is moved against the internal elasticity of said base in the direction of the arrow A, i.e. towards the actuating element 8. The adjustment element 24 rests with its end 24.2 only against the upper side of the switching spring base 16, which upper side faces towards the temperature sensor 2.

(18) The adjustment of the switching point of the first switching system 3 is usually carried out by moving the rod-shaped expansion element 6 by a required setting or adjusting stroke corresponding to the desired switching point and by subsequently fixing the rod-shaped expansion element 6 at the tube section 7. After adjusting the switching point of the first switching system 3, the switching system 4, which is not adjusted yet, is also in a closed state although the temperature at the temperature sensor 2 lies below the switching point of the switching system 4.

(19) In order to adjust the switching point of the switching system 4, the temperature controller 1 is clamped with its temperature controller housing 5 in an adjusting device, and the curved region 24.3 of the adjustment element 24 is deformed by means of the adjusting plunger 25 by advancing the adjusting plunger 25 and thereby increasing the distance between the ends 24.1 and 24.2 until the switching system 4 opens, i.e., until the spring contact 21 lifts off from the contact 22, which can be detected and/or controlled without any problems with an electrical contact test or an electrical measuring circuit connected to the connectors 18 and 23. As soon as the switching system 4 opens, the current position of the adjusting plunger 25 is saved. The adjusting plunger 25 is moved back and it is checked whether the switching system 4 continues to remain open. Since there is always an elastic component involved when reforming the curvature of the curved region 24.3, moving the adjusting plunger 25 backwards normally results in closing the switching system 4 again. In a further adjusting step or when advancing the adjusting plunger 25 again, the position of the adjusting plunger 25 reached and saved during the preceding adjusting step is exceeded by a small stroke or amount (offset). Thereafter, saving of the current position of the adjusting plunger 25 and monitoring whether the switching system 4 remains open after the back movement of the adjusting plunger 25 is carried out again.

(20) If necessary, this method can be repeated several times until the switching system 4 remains open and thus a sufficient, non-elastic or permanent deformation of the adjustment element 24 is achieved. So, the switching system 4 would open at a temperature that corresponds to that temperature that is detected by the temperature sensor 2 during the adjustment. If this is, for example, the normal ambient temperature and opening the switching system 4 is already desired at a switching point above the normal ambient temperature, for example at the switching point between 50 C. and 80 C., the adjustment then is carried out in such a manner that the adjustment element 24 is deformed in a first step only to such an extent that first, the switching system 4 actually opens, but closes again after the adjusting plunger 25 is moved back. Proceeding from the saved position of the adjusting plunger 25 at the end of the first adjusting step, another movement of the adjusting plunger 25 by a small stroke or amount (offset) takes place again. The latter is set in such a manner that this movement is not enough to keep the switching system 4 open after the adjusting plunger 25 is moved back, but that it moves the end 16.2 only to such an extent that the desired switching point above the ambient temperature is reached.

(21) Furthermore, when adjusting the switching system 4, there is also the possibility to provide a spacer, e.g. in the form of an adjusting platelet 26 between the actuating element 8 and the switching spring 19, wherein the thickness of this platelet then corresponds to the temperature difference (temperature offset) between the transition temperature during the adjustment and the temperature of the desired switching point. Adjusting is carried out in at least one, but preferably in at least two steps in such a manner that the switching system 4 remains open after adjusting and retracting the adjusting plunger 25. Then, the spacer is removed. For setting the temperature offset as precisely as possible, the ambient temperature can also be taken into account during the adjustment and can be compensated accordingly.

(22) FIG. 3 shows as a further embodiment in a partial illustration a temperature controller la which differs from the temperature controller 1 substantially only in that the adjustment element 24, which rests with its lower end 14.2 against the upper side of the switching spring base 16, is not oriented at an angle, but perpendicular or substantially perpendicular with respect to the switching spring base 16.

REFERENCE LIST

(23) 1, 1a temperature controller 2 temperature sensor 3, 4 switching system 5 temperature controller housing 6 rod-shaped expansion element 7 tube section 8 actuating element 8.1 spring 9 switching spring base 10 fastening point of switching spring base 11 connector 12 switching spring 13 spring contact 14 contact 15 connector 16 switching spring base 16.1, 16.2 end of switching spring base 16 17 fastening point 18 connector 19 switching spring 20 fastening of switching spring 19 on the switching spring base 16 21 spring contact 22 contact 23 connector 24, 26 adjustment element 24.1, 24.2 end of adjustment element 24.3 curved region of the adjustment element 24.3.1, 24.3.2, 24.3.3 leg 25 adjusting plunger A longitudinal direction of the adjustment element J adjusting direction AT axis of the temperature sensor 2