EP2650897A1 - Temperature-sensitive electrical switch and method for producing the same - Google Patents

Abstract

The switch has a thermal double-metal snapping element i.e. snapping disk, and a spring element (6) designed as a movable contact section. The contact section is moved against a fixed contact section (12). A pressure pin acts as an effective connection between the snapping element and the spring element. A switch bridge unit is arranged in a housing and provided with a switch bridge and a plastic component (16). The bridge comprises two parts that form respective connecting sections (10, 11). The parts are embedded in the component and connected with one another by the component. The parts of the switch bridge are designed as a stamping part made from metal. An independent claim is also included for a method for manufacturing a temperature-sensitive electrical switch.

Description

FIELD OF THE INVENTION

The invention relates to a temperature-sensitive electrical switch comprising a snap element, preferably a snap disc made of bimetallic strip and a spring element as a movable contact portion, a fixed contact portion against which the movable contact portion for closing the contact is movable, a pressure pin as operative connection between the snap element and spring element, a pin guide , a housing and a hood.

Moreover, the invention relates to a method for producing a temperature-sensitive electrical switch according to the invention.

STATE OF THE ART

Temperature-sensitive electrical switches are used for the temperature-dependent switching or closing and / or interruption of an electrical circuit, for example as a disconnection device in a kettle, as overload protection or in regulators for boilers. Therefore, the term thermostat is common for these switches.

The structure of these thermostats includes a snap-action element made of bimetallic strip, which is usually designed as a snap-action disc as a temperature-sensitive element. The snap disc may be circular or have other shapes, e.g. square, rectangular etc.

The snap disc has a curvature, for example in the form of a flat spherical cap, which changes abruptly at a lower and an upper snap temperature. In this case, a spring element is moved, which contacts a fixed contact element in a buckling state of the snap disk and has no contact with the fixed contact element in the other curvature state. As an operative connection between the snap-action disc and the spring element, a pressure pin guided in a pin guide is used, which is preferably designed to be electrically insulating. In order to avoid a transmission of an initially slow ("analogue") stroke of the snap-action disc snap-fitting into the other curvature state on the spring element, the pressure pin does not simultaneously touch the snap disc and the spring element in a buckling state of the snap disc. Only when following the slow, sudden ("digital") stroke of the snapping snap-action disc the pressure pin touches the snap disc and the spring element simultaneously. As a result, sparking is avoided.

Thermostats known from the prior art have the following structure, wherein the spring element basically contacts the fixed contact element. First, in order to allow a satisfactory contact, a contact rivet is attached to the spring element. The spring element is subsequently riveted by means of a connecting rivet with a connector or terminal and a housing of the thermostat, wherein the housing is usually made of plastic. Another contact rivet will be on Fixed contact element mounted. Then another terminal is also riveted to the fixed contact element in the housing with a connecting rivet.

As a result, the pin guide is placed and determines the distance between the pressure point of the spring element and the support of the snap-action disc. Now a pressure pin with appropriate length is installed. As the last manufacturing step, the disc is used and a hood to the housing, preferably by crimping, connected.

A disadvantage of the structure described above, especially the high number of items to call. Furthermore, the design of the parts is not very suitable for automated production. In addition, the bias or contact force of the spring element can not be readjusted and is dependent on the tolerance of several components. In this context, the riveting of the terminals to call the spring element and fixed contact element through the plastic housing, which loosens experience with time. This leads to a poor electrical transition and a switching behavior that deviates from the original setting.

OBJECT OF THE INVENTION

The object of the present invention is to provide a thermostat or a method for its production, wherein the abovementioned disadvantages are avoided. In particular, a reduction of the individual parts and an improvement of the automation possibilities in production should be achieved. In addition to a permanently stable connection, both in mechanical and in electrical terms, between terminals and a fixed contact element or a spring element of temperature-sensitive electrical switch can be realized.

PRESENTATION OF THE INVENTION

According to the invention, a reduction of the individual parts of a temperature-sensitive electrical switch, which comprises a snap element made of bimetallic strip and a spring element, a pressure pin as operative connection between snap element and spring element, a pin guide, a housing and a hood, achieved by the use of a switching bridge unit, which in turn only a few Has individual parts. Specifically, the switching bridge unit consists of a switching bridge, which in turn consists of only a first and a second part, and a plastic part. The first and second part of the switching bridge are embedded in this plastic part and are thereby mechanically connected to each other, electrically isolated from each other and fixed in position to each other. The switching bridge unit can be attached to a - depending on the desired switching path and the length of the pressure pin predetermined position - in the housing.

The first part comprises a first terminal section and a fixed contact section. The second part has a connection section for a spring element and a second terminal section. That the first terminal portion and the fixed contact portion and the second terminal portion and the terminal portion are each made in one piece.

The spring element is a movable contact portion and can be moved to close the contact against the fixed contact portion. Here, the pressure pin acts as an operative connection between the snap disc and the spring element. Therefore, it is at a temperature sensitive electrical switch, comprising a snap element, preferably a snap disc made of bimetallic strip and a spring element as a movable contact portion, a fixed contact portion against which the movable contact portion for closing the contact is movable, a pressure pin as an operative connection between the snap element and spring element, a pin guide, a housing and a hood, according to the invention provided that a mounted in the housing switching bridge unit is provided, which consists of a switching bridge and a plastic part, that the switching bridge consists of a first and a second part, wherein the first part of a first terminal portion and the fixed contact portion and the second part a second terminal portion and a terminal portion to which the spring member is fixed, formed, and that the first and the second part embedded in the plastic part and connected by the plastic part and Lagef to each other ixed.

So that the terminal sections can act as connecting pieces, they protrude out of the plastic part. The fixed contact portion also projects out of the plastic part to be contacted by the spring element can. Accordingly, it is provided in a preferred embodiment of the switch according to the invention that at least the first and the second terminal portion and the fixed contact portion protrude from the plastic part.

The material used for the first and second parts of the switching bridge is metal. This is on the one hand electrically conductive, on the other hand, the first and the second part can be stamped in one step on a metal strip, which simplifies production. Accordingly, it is provided in a preferred embodiment of the switch according to the invention, that it is the first and at second part of the switching bridge is in each case a stamped part made of metal.

After punching, the first part initially has a substantially flat and in the broadest sense L-shaped form. One segment of the L-shape is formed by the first terminal portion and a first center portion, another segment of the L-shape by the fixed contact portion. The fixed contact portion thus forms an end region of the first part of the switching bridge.

For use in the switch according to the invention, the fixed contact section is bent out of the plane of the first center section and bent again at its end pointing away from the first center section. The bent fixed contact portion thus forms an L-shape. Together with the first center section of the fixed contact portion forms a U-shape with a first leg, a center segment and a second leg. Here, the first center section forms the first leg. The fixed contact section forms the center segment adjoining the first leg and the second leg, which runs essentially parallel to the first leg, ie, except for a maximum deviation of 5 °. Preferably, the first leg with the center segment and the center segment with the second leg in each case forms a right angle. Accordingly, it is provided in a preferred embodiment of the switch according to the invention that the fixed contact portion forms an end portion of the first part of the switching bridge, wherein the first part of the first terminal portion, a first center portion and the fixed contact portion is that the fixed contact portion L-shaped out of the plane the first center portion is bent, and that the fixed contact portion and the first center portion form a U-shape having a first leg, a center segment and a second leg, wherein the first Center portion forms the first leg and the fixed contact portion to the first leg substantially parallel second leg and the center segment.

Thus, after the bending of the fixed contact element, a characteristic shape of the first part results, which results from the bending of the fixed contact element around bending lines extending parallel to the longitudinal axis of the first terminal section, in the case where the first terminal section is in the same plane how the first center section lies, ie before a possible bend of the first terminal section. The latter is initially given immediately after the punching process, where also the fixed contact element section lies in the same plane as the first center section. Accordingly, it is provided in a preferred embodiment of the switch according to the invention that the center segment is bent relative to the first leg to a first bending line which is parallel to the longitudinal axis of the first terminal portion, and that the second leg is bent relative to the center segment to a second bending line, which runs parallel to the first bending line.

The contacting of the fixed contact portion by the spring element is preferably carried out on the second leg. The spring element is in turn attached in a particularly preferred embodiment of the switch according to the invention with one end to the connection portion of the second part of the switching bridge and thus electrically connected to the second terminal portion.

In order to enable a particularly secure contacting of the spring element with the fixed contact portion, it is provided in a particularly preferred embodiment of the switch according to the invention that the spring element and the fixed contact portion each have a contact profile is attached, wherein the two contact profiles each other in a contact position - preferably flat - contact. That is, in the contact position, the spring element and the fixed contact portion are electrically conductively connected to each other.

The connecting portion of the second part of the switching bridge is located in a particularly preferred embodiment of the switch according to the invention in the same plane as the first center portion of the first part of the switching bridge. In this case, the connection section is arranged opposite the region of the fixed contact section or the center segment adjoining the first center section. Since the contacting of the fixed contact section is effected by the spring element on the second leg and the second leg is not in any case in the same plane as the first center section, the spring element has a U-shaped bend. That In a particularly preferred embodiment of the switch according to the invention it is provided that the spring element is bent in a U-shape. On the one hand, this ensures that a free end of the spring element, with which the contacting of the fixed contact section takes place, lies in a plane which lies substantially parallel to the plane of the second leg and is significantly less spaced therefrom than the plane of the first center section. On the other hand, the U-shaped bend allows an approximately perpendicular engagement of the pressure pin on the spring element, i. the longitudinal axis of the pressure pin is substantially perpendicular to that surface of the spring element which the pressure pin mechanically contacts. This guarantees a particularly good operative connection between snap disc and spring element and thus a reliable switching.

Accordingly, it is provided in a particularly preferred embodiment of the switch according to the invention that the spring element has a free end to contact the fixed contact element. At the free end can to better contact a contact profile be appropriate. This is also useful in the case where the spring element is not bent in a U-shape, but projects, for example, obliquely away from the connection section towards the fixed contact section or the second leg.

Alternatively, it would of course also conceivable that the connection section protrudes from the plane of the first center section in the direction of the second leg. In this case, the spring element could be made only strip-shaped and planar and would then lie in a plane parallel to the plane of the first center section, with the free end near the second leg.

It should also be noted that a protruding of the connecting portion could be realized in particular by bending the connecting portion - in an analogous manner to the above-described bending of the fixed contact portion. That taken by itself, a correspondingly bent connecting section would have an L-shape or a correspondingly curved connecting section would form a U-shape with at least one area of the second part of the switching bridge.

In a particularly preferred embodiment of the switch according to the invention, the spring element is basically in the contact position, since this guarantees a particularly stable electrical transition. When snapping the snap disc of the pressure pin presses against the spring element, whereupon the electrical contact is interrupted. In this case, it is inventively provided that a contact profile is mounted on that side of the second leg which faces the first leg. Accordingly, the free end of the spring element between the first and the second leg is arranged. The U-shaped bend in this case causes a particularly good pressing of the free end of the spring element attached contact profile on the contact profile of Fixkontaktabschnitts.

Of course, an embodiment of the switch according to the invention is conceivable in which the spring element is basically not in the contact position to possibly make the necessary bending operations of the fixed contact portion and the spring element easier. In this case, when snapping the snap disc of the pressure pin presses against the spring element and closes the electrical contact. Assuming that the contacting takes place on the second leg, the second leg is arranged between the first leg and the free end of the spring element. Accordingly, it is provided in one embodiment of the switch according to the invention that the free end of the spring element has a side which faces the first and the second leg simultaneously. Of course, it is advisable to attach a contact profile for better contacting on this side of the free end of the spring element - and, analogously, a contact profile on that side of the second leg which faces the free end of the spring element.

This results in a shape of the second part with a fixed spring element, which fails analogously to the characteristic shape of the first part with a bent fixed contact portion. In essence, there is a mirrored shape of the second part with attached spring element to the characteristic shape of the first part with bent fixed contact portion. Here, depending on the embodiment, the normal distance between the free end of the spring element and the first center section is smaller or larger than the normal distance between the second leg and the first center element, wherein the normal distances are measured normal to the first center section. In the case of a U-shaped bent spring element, it is therefore in a particularly preferred embodiment the switch according to the invention provides that the opening of the U-shape of the spring element to the opening of the formed by the first leg, the center segment and the second leg U-shape.

In the event that the spring element is not bent in a U-shape, it can be said by analogy with the above that the connection section forms an end region of the second part of the switching bridge, the second part consisting of the second terminal section, a second center section and the connection section , A U-shape is formed here by the spring element, the connection section and the second center section. Accordingly, it is provided in a particularly preferred embodiment of the switch according to the invention that the connection portion forms an end portion of the second part of the switching bridge, wherein the second part of the second terminal portion, a second center portion and the connection portion consists, and that the second center portion, the connection portion and the spring element forming a U-shape, the opening to the opening of the formed by the first leg, the center segment and the second leg U-shape. It should be noted that in this embodiment, the spring element can in principle be very well bent and not necessarily be executed flat.

The analogy to the shape of the first part is completed in a further particularly preferred embodiment of the switch according to the invention by providing that the second terminal section is arranged parallel to the first terminal section. In this case, the terminal sections are arranged in particular in alignment.

• Stanzen eines ersten und zweiten Teils einer Schaltbrücke an einem Metallstreifen mittels eines Stanzmoduls, wobei der erste Teil einen ersten Terminalabschnitt sowie einen Fixkontaktabschnitt ausbildet und der zweite Teil einen zweiten Terminalabschnitt sowie einen Anschlussabschnitt für ein Federelement;
• Befestigen des Federelements mit einem Ende am Anschlussabschnitt;
• teilweises Umspritzen des ersten und zweiten Teils mit Kunststoff;
• Biegen des Fixkontaktabschnitts in eine mit einem ersten Mittenabschnitt des ersten Teils U-förmige Position, wobei der erste Mittenabschnitt einen ersten Schenkel bildet und der Fixkontaktabschnitt einen zum ersten Schenkel im Wesentlichen parallelen zweiten Schenkel sowie ein Mittensegment.

According to the above statements, it is provided according to the invention in a method for producing a temperature-sensitive electrical switch that the Method comprising the following steps to allow an optimized construction with a reduction of the individual parts of the switch:

• Punching a first and second part of a switching bridge on a metal strip by means of a punching module, wherein the first part forms a first terminal portion and a fixed contact portion and the second part forms a second terminal portion and a connection portion for a spring element;
• Attaching the spring member to one end at the terminal portion;
• partially encapsulating the first and second parts with plastic;
• Bending the fixed contact section into a U-shaped position with a first center section of the first section, the first center section forming a first leg and the fixed contact section forming a second leg substantially parallel to the first leg and a center segment.

Punching on the metal strip means that the first and second parts are still connected after punching with the metal strip and not completely separated from it. By leaving the first and second part of the metal strip, a very fast and accurate positioning and easy further transport to and in other tool modules is made possible. The tool for producing the temperature-sensitive electrical switch thus consists of individual modular components, which are arranged one behind the other, wherein the number and order can be predetermined.

To carry out the method according to the invention, for example, the following construction is possible: the punching module for punching the first and second parts on the metal strip; a welding assembly module for securing the spring element; another welding assembly module for attaching contact profiles on the spring element and the fixed contact portion; a bending module for bending terminal wings; an injection molding module for partially encapsulating the first and second parts with plastic; a flexural modulus for bending the spring element; another bending module for bending the fixed contact portion; and finally, a punching module for punching the first and second parts out of the metal strip.

It should be noted that the sequence of certain steps or modules can be changed. For example, the bending of the terminal wings can also take place at a later time. Likewise, it is sometimes advantageous to carry out the punching at a later time in order to first transport the switching bridge unit on the metal strip for further processing to other machines / tools or tool modules.

Since the fixed contact portion and the first terminal portion are integrally formed with each other by the first part of the switching bridge, a best possible stable connection, both in mechanical and in electrical terms, guaranteed. The use of failure-prone rivets is omitted here.

In a particularly preferred embodiment of the method according to the invention, the first and the second part of the switching bridge are generated simultaneously by means of the punching module. As a result, time and a or, if one thinks of possibly necessary steps for positioning the first and second parts to each other, saved several production steps.

When punching holes and / or tabs can also be formed on the first and second part of the switching bridge. These guarantee an optimal hold in the plastic, with which the first and second part are overmoulded. By the Injection molding the first and second parts are positioned very precisely to each other and fixed in position.

In order to realize a permanently stable connection, both mechanically and electrically, between the spring element and the connection section, it is provided in a particularly preferred embodiment of the method according to the invention that the fastening of the spring element to the connection section by spot welding or by a compression Press-joining process takes place. On the use of trouble-prone rivets, which would represent even more items, can thus be dispensed with.

In order to improve the electrical contact contact profiles are provided. Accordingly, it is provided in a particularly preferred embodiment of the method according to the invention that before the partial encapsulation in each case a contact profile is attached to a free end of the spring element and the fixed contact portion.

Analogously, it is provided in a particularly preferred embodiment of the method according to the invention that the fastening of the contact profile on the spring element and / or on the fixed contact section by a welding operation, for example, spot welding or laser welding takes place. On the use of trouble-prone rivets, which would represent even more items, can thus be omitted here, although their use is not excluded in principle.

In order to guarantee a connection possibility to the terminal sections and not to adversely affect the contact of the spring element on Fixkontaktabschnitt and thus not adversely affect the switching behavior of the switch, it is provided in a particularly preferred embodiment of the method according to the invention that during partial encapsulation of the first and second Part of the switching bridge at least the first and the second terminal portion and the fixed contact portion are not encapsulated. That is, the first and second terminal portion and the fixed contact portion protrude from a plastic part, which arises during encapsulation, out.

In order to protect the connection of the spring element with the connection portion, it is provided in a particularly preferred embodiment of the method according to the invention that the partial end of the spring element is also encapsulated during partial encapsulation.

In addition, holes and / or tabs can be provided at the connected end of the spring element, which guarantee optimum hold in the plastic. In any case, the positioning of the connected end of the spring element is optimized relative to the first and the second part of the switching bridge by encapsulating and the connected end of the spring element is additionally fixed in position - in addition to the attachment to the connection section.

In order to realize an embodiment of the switch, in which a particularly stable electrical transition between the spring element and fixed contact portion is guaranteed, the fixed contact portion is bent so that it contacted the spring element in principle. That The spring element is thus basically in a contact position. When snapping the snap disc of the pressure pin presses against the spring element, whereupon the electrical contact is interrupted.

Accordingly, before bending the fixed contact section, bending of the spring element in the direction of the fixed contact section takes place in a mold, preferably a U-shape. Therefore, it is provided in a preferred embodiment of the method according to the invention, that the spring element in the direction of the fixed contact portion, in a, preferably U-shaped shape is bent and that the bending of the spring element takes place prior to bending of the fixed contact portion.

Accordingly, then the fixed contact portion must be bent so that the free end of the spring element between the first and the second leg is arranged and preferably the contact profiles contact each other surface. Therefore, it is provided in a particularly preferred embodiment of the method according to the invention that when bending the fixed contact portion, the free end of the spring element between the first and the second leg is brought into a contact position in which the contact profiles contact each other. By bringing both the fixed contact portion and the spring element by means of bending operations in the contact position, a contact force with which the spring element presses against the fixed contact portion or press the two contact profiles against each other, specifically influenced and adapted to the existing requirements.

As shown above, the punching on the metal strip has the advantage that the first and second part are still connected to the metal strip and can be easily and quickly transported to other tool modules, without changing their position to each other. That Steps for a new positioning of the first and second parts to each other in the next tool module omitted, whereby the number of process steps is minimized.

Therefore, it is provided in a further preferred embodiment of the method according to the invention that the fastening of the spring element takes place in a welding assembly module on the metal strip.

Analogously, it is provided in a further preferred embodiment of the method according to the invention that the fastening the contact profiles is carried out in a welding assembly module on the metal strip.

Accordingly, it is also provided in a particularly preferred embodiment of the method according to the invention that the partial encapsulation with plastic takes place on the metal strip in an injection molding module.

As already mentioned, the terminal wings can be bent on the metal strip. It is therefore provided in a further preferred embodiment of the method according to the invention that terminal wings of the first and second terminal sections are bent in a bending module on the metal strip.

Finally, the terminal sections can be bent into a predefinable end position in which they are available for the connection. Accordingly, it is provided in a preferred embodiment of the method according to the invention that the first and second terminal portion are bent into an end position, preferably in a bending module on the metal strip.

BRIEF DESCRIPTION OF THE FIGURES

The invention will now be explained in more detail with reference to an embodiment. The drawings are exemplary and are intended to illustrate the inventive idea, but in no way restrict it or even reproduce it.

Fig. 1

eine axonometrische Ansicht eines temperaturempfindlichen elektrischen Schalters

Fig. 2

eine Aufsicht auf einen temperaturempfindlichen elektrischen Schalter

Fig. 3

eine Schnittansicht eines temperaturempfindlichen elektrischen Schalters entsprechend der Schnittlinie A-A in Fig. 2

Fig. 4

eine Schnittansicht eines temperaturempfindlichen elektrischen Schalters entsprechend der Schnittlinie B-B in Fig. 2

Fig. 5

eine Aufsicht auf eine Schaltbrücke bestehend aus einem gestanzten ersten und zweiten Teil

Fig. 6

eine axonometrische Ansicht einer Schaltbrücke mit befestigtem Federelement sowie befestigten Kontaktprofilen

Fig. 7

eine axonometrische Ansicht einer Schaltbrückeneinheit mit befestigtem Federelement sowie befestigten Kontaktprofilen

Fig. 8

eine axonometrische Ansicht einer Schaltbrückeneinheit mit Federelement und Fixkontaktabschnitt in einer Kontaktposition und Terminalabschnitte in einer Endposition, mit dem Fixkontaktabschnitt im Vordergrund

Fig. 9

andere Perspektive der Fig. 8, mit dem Federelement im Vordergrund

Showing:

Fig. 1

an axonometric view of a temperature sensitive electrical switch

Fig. 2

a plan view of a temperature-sensitive electrical switch

Fig. 3

a sectional view of a temperature-sensitive electrical switch according to the section line AA in Fig. 2

Fig. 4

a sectional view of a temperature-sensitive electrical switch according to the section line BB in Fig. 2

Fig. 5

a plan view of a switching bridge consisting of a punched first and second part

Fig. 6

an axonometric view of a switching bridge with fixed spring element and fixed contact profiles

Fig. 7

an axonometric view of a switching bridge unit with attached spring element and fixed contact profiles

Fig. 8

an axonometric view of a switching bridge unit with spring element and fixed contact portion in a contact position and terminal portions in an end position, with the fixed contact portion in the foreground

Fig. 9

different perspective of Fig. 8 , with the spring element in the foreground

WAYS FOR CARRYING OUT THE INVENTION

In Fig. 1 an axonometric view of a temperature-sensitive electrical switch 1 according to the invention is shown, which is also referred to as a thermostat. This has a preferably made of plastic housing 4, which is closed on one side by means of a hood 7. In this case, the hood 7 is preferably made of a metal, for example aluminum, made and connected by crimping with the housing 4. Furthermore are in Fig. 1 a first 10 and a second terminal portion 11 can be seen, which serve for electrical connection from the outside.

Fig. 2 shows a plan view of the switch 1 of Fig. 1 with indicated section lines AA and BB and arrows indicating the respective viewing directions.

Fig. 3 shows a sectional view along the section line AA in Fig. 2 , In this case, a curved snap disc 2, which is made of a bimetallic strip and has a circular outline, can be seen in a first curvature state. In this, which is present at an initial temperature, the snap disc 2 rests on an inner shoulder 27 of the housing 4.

A pressure pin 5 does not touch the snap disc 2 in this position or in this curvature state scarcely and is supported on a spring element 6, without exerting on the spring element 6 a pressure. As in Fig. 4 which is a sectional view along the section line BB in Fig. 2 In this case, contacts the spring element 6 in a contact position 18 a fixed contact portion 12. More specifically, is a two-dimensional contact of a contact profile 14 which is fixed to a free end 25 of the spring element 6, with a contact profile 15, which on a Fix contact portion 12 is fixed, before.

The spring element 6 is bent in a U-shape and fastened with its other end 26 to a connection section 13. The connection section 13 is located on a second part 9 of a switching bridge 3 (cf. Fig. 5 ), as well as the second terminal portion 11. That is, the spring element 6 is electrically connected to the second terminal portion 11.

The fixed contact portion 12 in turn is located on a first part 8 of the switching bridge 3 (see. Fig. 5 ), as well as the first terminal portion 10. That is, the fixed contact portion 12 is electrically connected to the first terminal portion 10. In the contact position 18, the two terminal sections 10, 11 are thus connected to one another in an electrically conductive manner.

The first 8 and second part 9 of the switching bridge 3 are embedded in a plastic part 16. On the one hand, the first 8 and the second part 9 are electrically insulated from each other by the plastic part 16. On the other hand, the plastic part 16 positions the first 8 and second part 9 to each other and fixes their position. Finally, the housing 4 is attached to the plastic part 16. The first part 8, the second part 9 and the plastic part 16 form a switching bridge unit 20.

Changes the snap disk 2 at a certain, usually compared to the initial temperature raised first temperature their curvature state abruptly, so the snap disc 2 presses against the hood 7 and on the pressure pin 5, which in turn depresses the spring element 6. In this way, the electrical contact between the first 10 and the second terminal section 11 is interrupted. The pressure pin 5 is in this movement of a pin guide 17 (see. Fig. 3 ) guided.

In another, usually compared to the first temperature significantly lower temperature jumps the snap disc 2 back into the in FIG. 3 and FIG. 4 shown vaulting state. The spring element 6 can now spring back into the contact position 18 and pushes the pressure pin 5 through the pin guide 17 in the in FIG. 3 and FIG. 4 shown position.

Fig. 5 shows a plan view of the switching bridge 3, immediately after the first 8 and second part 9 by means of a Punching module (not shown) were simultaneously punched on a metal strip (not shown). The first part 8 forms here as the second part 9 is a planar element and lies with this in the same plane.

In Fig. 5 It can be clearly seen that the first part in the broadest sense has the form of an L 'rotated by 90 °, the fixed contact section 12 forming a segment of the L' s. Another segment of the L's is formed by a first center section 21 and the first terminal section 10. In this case, wings 28 of the first terminal portion 10 can be seen, which are subsequently bent by dashed lines drawn bending lines 30 by 180 °. Analog are in Fig. 5 Also corresponding wing 29 of the second terminal portion 11 can be seen, which are subsequently bent by dashed lines drawn bending lines 31 by 180 °.

Fig. 6 shows an axonometric view of the switching bridge 3, wherein the fixed contact portion 12, the contact profile 15, preferably by spot welding or laser welding is attached. At the connection section 13, the spring element 6 is fastened to the end 26, preferably by spot welding or by a compression-press-joining or toxing process. At the free end 25 of the spring element 6, in turn, the contact profile 14, preferably fixed by spot welding or laser welding.

In the axonometric view of the Fig. 7 the first 8 and second part 9 of the switching bridge are already encapsulated with plastic or embedded in the plastic part 16, with which they form the switching bridge unit 20. To support the housing 4, the plastic part 16 also support elements 32, which from the plane of the first center section 21 (see, eg Fig. 6 ) and on which an inner side 33 of the housing 4 is supported (cf. Fig. 3 ).

In the axonometric view of the Fig. 8 the fixed contact portion 12 and the spring element 6 are bent into the contact position 18. For this purpose, the fixed contact portion 12 along a first bending line 34 (see. Fig. 5 ) is bent out of the plane of the first center section 21 by 90 ° and then by a further 90 ° along a second bending line 35 (cf. Fig. 5 ). Thus, the first center portion 21 now forms a first leg 22 and the fixed contact portion 12 a center segment 23 and a second leg 24 of a U-shape. The first bend line 34 may be considered as a fictitious boundary between the first center section 21 and the fixed contact section 12 for the purpose of simple viewing. Both the first 34 and the second bending line 35 run parallel to a longitudinal axis 39 of the first terminal section 10, as long as it is not bent out of the plane of the first center section 21, cf. Fig. 5, Fig. 6 and Fig. 7 ,

The spring element 6 in turn is bent starting from its attached end 26 U-shaped, so that the free end 25 is disposed between the first 22 and the second leg 24. In this case, the spring element 6 presses the attached at its free end 25 contact profile 14 against the attached fixed contact portion 12 contact profile 15. In the preparation of the illustrated embodiment, the bending of the spring element 6 takes place before bending the fixed contact portion 12th

Fig. 9 shows an axonometric view of the subject of the Fig. 8 under a different viewing direction, with the fixed end 26 of the spring element 6 in the foreground. The terminal sections 10, 11 are in this case in an end position 19. Opposite the Fig. 6 the terminal sections 10, 11 are each bent by 90 °, namely antiparallel to the support members 32. The bend runs for the first terminal portion 10 to a bending line 37 and for the second terminal portion 11 to a Bend line 38, see Fig. 5 , The bending line 37 can be regarded as a fictitious boundary between the first terminal section 10 and the first center section 21 for the purpose of simple viewing. Similarly, for ease of viewing, bend line 38 may be considered a fictitious boundary between second terminal portion 11 and a second center portion 36 of second portion 9. <U> LIST OF REFERENCES </ u> 1 switch 2 snap disk 3 jumper 4 casing 5 pushpin 6 spring element 7 Hood 8th First part of the switching bridge 9 Second part of the switching bridge 10 First terminal section 11 Second terminal section 12 Fixkontaktabschnitt 13 Connection section for spring element 14 Contact profile of the spring element 15 Contact profile of the fixed contact section 16 Plastic part 17 pin guide 18 contact position 19 End position of the terminal sections 20 Switching bridge unit 21 First middle section 22 First leg 23 middle segment 24 Second thigh 25 Free end of the spring element 26 Attached end of the spring element 27 Inner shoulder of the housing 28 Wing of the first terminal section 29 Wing of the second terminal section 30 Bend line for wings of the first terminal section 31 Bend line for wings of the second terminal section 32 support element 33 Inside of the housing 34 First bending line of the fixed contact section 35 Second bending line of the fixed contact section 36 Second middle section 37 Bend line of the first terminal section 38 Bend line of the second terminal section 39 Longitudinal axis of the first terminal section

Claims (15)

Temperature sensitive electrical switch (1) comprising a snap element, preferably a snap disc (2) made of bimetallic strip and a spring element (6) as a movable contact portion, a fixed contact portion (12) against which the movable contact portion for closing the contact is movable, a pressure pin ( 5) as an operative connection between snap element and spring element (6), a pin guide (17), a housing (4) and a hood (7), characterized in that in the housing (4) fixed switching bridge unit (20) is provided which a switching bridge (3) and a plastic part (16), that the switching bridge (3) consists of a first (8) and a second part (9), wherein the first part (8) has a first terminal portion (10) and the fixed contact portion (12) and the second part (9) forms a second terminal portion (11) and a terminal portion (13) to which the spring element (6) is fixed, and that the first (8) and the second part (9) embedded in the plastic part (16) and connected to each other by the plastic part (16) and fixed in position to each other. Switch (1) according to claim 1, characterized in that at least the first (10) and the second terminal portion (11) and the fixed contact portion (12) protrude from the plastic part (16). Switch (1) according to one of Claims 1 to 2, characterized in that the first (8) and the second part (9) of the switching bridge (3) are each a stamped part made of metal. Switch (1) according to one of claims 1 to 3, characterized in that the fixed contact portion (12) has a End portion of the first part (8) of the switching bridge (3), wherein the first part (8) of the first terminal portion (10), a first center portion (21) and the fixed contact portion (12) is that the fixed contact portion (12) L is bent from the plane of the first central portion (21), and that the fixed contact portion (12) and the first center portion (21) has a U-shape with a first leg (22), a center segment (23) and a second leg ( 24), the first center section (21) forming the first leg (22) and the fixed contact section (12) forming the second leg (24) substantially parallel to the first leg (22) and the center segment (23). A switch (1) according to claim 4, characterized in that the center segment (23) is bent relative to the first leg (22) about a first bending line (34) which is parallel to the longitudinal axis (39) of the first terminal section (10), and in that the second limb (24) is bent relative to the center segment (23) about a second bending line (35) which runs parallel to the first bending line (34). Switch (1) according to one of claims 1 to 5, characterized in that the spring element (6) and the fixed contact portion (12) each have a contact profile (14, 15) is mounted, wherein the two contact profiles (14, 15) in a Contact contact position (18). Switch according to one of claims 1 to 6, characterized in that the spring element (6) has a free end (25) to contact the fixed contact element (12). Switch (1) according to claim 7, characterized in that the free end (25) of the spring element (6) between the first (22) and the second leg (24) is arranged. Switch (1) according to claim 7, characterized in that the free end of the spring element (6) has a side which simultaneously faces the first (22) and the second leg (24). Switch (1) according to one of claims 1 to 9, characterized in that the spring element (6) is bent in a U-shape. Switch (1) according to claim 10, characterized in that the opening of the U-shape of the spring element (6) for opening the through the first leg (22), the center segment (23) and the second leg (24) formed U-shape has. Switch (1) according to one of Claims 4 to 9, characterized in that the connection section (13) forms an end region of the second part (9) of the switching bridge (3), the second part (9) being formed of the second terminal section (11). , a second center portion (36) and the terminal portion (13), and that the second center portion (36), the terminal portion (13) and the spring member (6) form a U-shape whose opening to the opening through the first leg (22), the center segment (23) and the second leg (24) formed U-shape. Switch (1) according to one of claims 11 to 12, characterized in that the second terminal section (11) is arranged parallel to the first terminal section (10). Method for producing a temperature-sensitive electrical switch (1), characterized in that it comprises the following steps: - Punching a first (8) and second part (9) of a Switching bridge (3) on a metal strip by means of a punching module, wherein the first part (8) forms a first terminal section (10) and a fixed contact section (12) and the second part (9) forms a second terminal section (11) and a connection section (13) for a spring element (6); - Attaching the spring element (6) having one end (26) on the connection portion (13); - Partial encapsulation of the first (8) and second part (9) with plastic; Bending the fixed contact portion (12) into a U-shaped form having a first center portion (21) of the first part (8), the first center portion (21) forming a first leg (22) and the fixed contact portion (12) forming a first one Leg (22) substantially parallel second leg (24) and a central segment (23). A method according to claim 14, characterized in that the first (8) and the second part (9) of the switching bridge (3) are generated simultaneously by means of the punching module.

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