METHOD OF ASSEMBLING A TEMPERATURE-DEPENDENT SWITCH

A method of assembling a temperature-dependent switch, comprising the steps of: (i) providing a switch housing having first and second electrodes and a temperature-dependent switching mechanism arranged in the switch housing, wherein the switching mechanism switches in a temperature-dependent manner between a closed state, which the switching mechanism assumes below a response temperature and in which the switching mechanism establishes an electrically conductive connection between the first and second electrodes, and an open state, which the switching mechanism assumes above the response temperature and in which the switching mechanism disconnects the electrically conductive connection; (ii) heating the switching mechanism to an assembly temperature above the response temperature to bring the switching mechanism in the open state; and (iii) attaching, by a material-bonded connection, a first external terminal to the first electrode or to a part electrically connected with the first electrode, while the switching mechanism is in the open state.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority from German patent application DE 10 2023 107 381.8, filed on Mar. 23, 2023. The entire content of this priority application is incorporated herein by reference.

FIELD

The present disclosure relates to a method of assembling a temperature-dependent switch.

BACKGROUND

Such temperature-dependent switches are used in a principally known manner to monitor the temperature of a device. For this purpose, the switch is brought into thermal contact with the device to be protected, e.g. via one of its outer surfaces, so that the temperature of the device to be protected influences the temperature of the switching mechanism arranged inside the switch.

The switch is typically connected electrically in series into the supply circuit of the device to be protected via connecting cables, so that the supply current of the device to be protected flows through the switch below the response temperature of the switching mechanism.

Such temperature-dependent switches comprise a temperature-dependent switching mechanism which is arranged in the switch housing and which, depending on its temperature, opens or closes an electrically conductive connection between two electrodes of the switch. More precisely, the temperature-dependent switching mechanism is configured to switch in a temperature-dependent manner between a closed state, which the switching mechanism assumes below a response temperature and in which the switching mechanism establishes the electrically conductive connection between the two electrodes, and an open state, which the switching mechanism assumes above the response temperature and in which the switching mechanism disconnects the electrically conductive connection.

The term “electrode” is to be interpreted in its most general way in this respect. This is an electrical contact point which serves to connect the switch to the electrical device to be protected, or which is in electrically conductive connection with such an external terminal of the switch. The electrodes can be led from outside into the interior of the switch housing, fixed to the switch housing or formed by parts of the switch housing itself.

To enable the above-mentioned temperature-dependent switching function, the temperature-dependent switching mechanism arranged inside the switch housing usually comprises a bimetal part that deforms abruptly from its low-temperature state to its high-temperature state upon reaching the response temperature, and thereby lifts off a movable contact part, which is arranged on a component that can move relative to the switch housing, from a stationary contact. The stationary contact is connected to one of the two electrodes, while the movable contact part interacts either with the bimetal part or with a spring part assigned to the bimetal part.

Constructions are also known in which the movable component of the temperature-dependent switching mechanism is designed as a contact bridge, which is carried by the bimetal part and directly establishes an electrical connection between the two electrodes. A temperature-dependent switch having a switching mechanism designed in such a way is disclosed, for example, in DE 197 08 436 A1.

In the two construction types mentioned above, the bimetal part is preferably configured as a bimetallic disc which, in the low-temperature state, preferably lies force-free in the switching mechanism. The spring part, which is preferably configured as a snap-action spring disc, is mechanically coupled with the bimetal part. The spring part is clamped in the switch housing, connected to it by a material bond or inserted into the switch housing.

In principle, however, it is also possible to completely dispense with the spring part, which is the case in particular in more cost-effective variants of such temperature-dependent switches. In such a case, the function of the spring part is taken over by the bimetal part. An exemplary temperature-dependent switch of this type is disclosed in DE 20 2009 012 616 U1.

Regardless of the construction type of the temperature-dependent switching mechanism, such temperature-dependent switches are typically electrically connected to the device to be protected via electrical supply lines or connecting parts that are fixed to the two electrodes. As a rule, flexible connection strands, rigid connection lugs or a connection cable are connected to the electrodes directly with a material connection. The strands, terminal lugs or cables are often soldered or welded to the switches known from the prior art.

However, soldering or welding of the supply lines or connecting parts has proven to be problematic in many respects.

The soldering processes commonly used are difficult to automate and are not environmentally friendly, in particular due to the lead-containing solder and the additional soldering flux used. In addition, cold solder joints can occur, which should be avoided at all costs.

An improved material-locking connection of the supply lines or connecting parts could therefore be realized in principle via welded connections, but these also have various disadvantages. In particular, the common welding processes pollute the environment and are also time-consuming and costly. Furthermore, such welding processes lead to the switch heating up considerably, which can lead to the welding triggering a switching operation of the temperature-dependent switching mechanism, which is generally undesirable.

Tests carried out by the applicant, in which terminal lugs or stranded wires were soldered or welded to the switch housing, have shown that the heat generated in the process can also cause the stationary contact inside the switch housing, with which the temperature-dependent switching mechanism interacts, to become detached from the electrode assigned to it.

The heat development can also cause the stationary contact and the movable contact part of the temperature-dependent switching mechanism to fuse together undesirably or at least change their geometry in such a way that the pre-assembled switches no longer switch or at least no longer switch reliably.

Furthermore, the heat development can lead to the bimetal part and/or the spring part being affected, so that the required switching properties of the switching mechanism change undesirably.

In the worst case, all of this can lead to a total functional failure of the switch.

The heat generated inside the switch housing is particularly pronounced if the switch housing is made of metal and the supply cables or connecting parts are welded or soldered directly to the switch housing. Due to the very good heat conduction properties of the metal, this results in particularly strong heat development inside the switch housing. This is all the more critical as the supply lines or connecting parts are usually only attached to the housing after the switching mechanism has already been mounted in the housing or the housing has been closed, i.e. after the switch itself is already present as a semi-finished component. Whether the heat generated inside the switch leads to any of the above-mentioned damage can then only be checked to a limited extent or at least only with great effort.

To prevent this, the supply lines or connecting parts are often fixed to the switch housing in advance, i.e. before the temperature-dependent switching mechanism is installed. However, this also comes with various disadvantages. On the one hand, it makes the handling of the switch more difficult during assembly, as the supply lines/connecting parts “get in the way” when the switching mechanism is installed in the switch housing. In addition, to achieve a sealed switch housing, it is easier to first insert the switching mechanism into the switch housing and seal the switch housing and then attach the supply lines or connecting parts to the switch housing.

In order to enable such an attachment of the supply lines or connecting parts to the switch housing after installation of the temperature-dependent switching mechanism and yet avoid the above-mentioned problem of undesirable heat development in the switch housing, DE 10 2019 110 448 A1, mentioned at the outset, proposes attaching the supply lines or connecting parts to the switch housing by means of ultrasonic welding. Compared to conventional welding methods, ultrasonic welding generates significantly less heat. It has been shown that most of the above-mentioned problems can be prevented in this way. However, the use of ultrasonic welding processes is relatively expensive, as very special welding tools are required.

SUMMARY

It is an object to provide an improved method of assembling a temperature-dependent switch, which overcomes the above-mentioned problems. In particular, the method is intended to enable a safe and sustainable attachment of the external terminals to the switch without thereby damaging the temperature-dependent switching mechanism arranged inside the switch.

According to an aspect, a method of manufacturing/assembling a temperature-dependent switch is provided, comprising the following steps:(i) providing a switch housing having a first electrode, a second electrode and a temperature-dependent switching mechanism arranged in the switch housing, wherein the temperature-dependent switching mechanism is configured to switch in a temperature-dependent manner between a closed state and an open state, wherein below a response temperature the temperature-dependent switching mechanism is in the closed state, in which the temperature-dependent switching mechanism establishes an electrically conductive connection between the first electrode and the second electrode, and above the response temperature the temperature-dependent switching mechanism is the open state, in which the temperature-dependent switching mechanism disconnects the electrically conductive connection;(ii) heating the temperature-dependent switching mechanism to an assembly temperature above the response temperature to bring the temperature-dependent switching mechanism in the open state; and(iii) joining a first external terminal to the first electrode or to a part electrically connected with the first electrode, while the temperature-dependent switching mechanism is in the open state.

Thus, in the presented method, it is also proposed to first install the switching mechanism in the switch housing and then to attach the first external terminal to the switch prefabricated as a semi-finished product by means of joining with the application of heat (e.g. by soldering or welding).

However, the applicant has recognized that the above-mentioned harmful effects, which can arise for the switching mechanism arranged inside the switch housing due to the heat generated by the joining process, can surprisingly be reduced or even completely avoided by additionally heating the switching mechanism before the first external terminal is attached in order to bring it to a temperature above the response temperature of the switching mechanism, which temperature is herein denoted as “assembly temperature”.

This heating of the switching mechanism in advance leads to the switching mechanism being deliberately brought into its open state. This not only interrupts the electrically conductive connection between the two electrodes, but also the heat conductive connection between the two electrodes caused by the switching mechanism. As a result, the heat generated when the first external terminal is attached by material-locking joining no longer has a damaging effect on the devices of the temperature-dependent switching mechanism, as this is already open and its components are not pressed against each other, unlike in the closed state.

Accordingly, the movable contact part typically provided on the switching mechanism is already lifted off the stationary contact part, against which the movable contact part rests in the closed state of the switching mechanism, before the first external terminal is attached. Direct heat conduction between the stationary contact part and the movable contact part is therefore excluded. Accordingly, it is also impossible for the movable contact part of the switching mechanism to be fused or welded with the stationary contact part or with the first electrode due to the heat generated when the first external terminal is attached to the first electrode.

Furthermore, the fragile devices of the switching mechanism (e.g. the bimetal part and the spring part) are typically further away from the joining point of the first external terminal or further away from the first electrode in the open state of the switching mechanism than in the closed state of the switching mechanism. Thus, the fragile devices of the switching mechanism are effectively protected from the heat generated during material-locking joining by the prior heating of the switching mechanism, during which the switching mechanism is brought into the open state.

Furthermore, the presented method has the advantage that an undesired switching operation of the switching mechanism, which can be caused by the heat development when attaching the first external terminal, is also effectively prevented, since the switching mechanism is already in its open state at this time and also remains in this open state due to the additional heat input during the attachment of the first external terminal.

In a refinement, the attaching of the first external terminal by material-locking joining with the application of heat comprises a soldering process or a welding process.

Since the switching mechanism is already in its open state during this process and the heat thereby introduced into the interior of the switch housing, as mentioned above, no longer has any damaging effects on the switching mechanism, conventional soldering and welding processes can be inserted with low costs. These material-locking joining processes can be automated, which leads to a further cost advantage.

In a further refinement, the switching mechanism is heated to the assembly temperature above the response temperature by heating the switch housing and the switching mechanism arranged therein by an external heat source.

The switching mechanism arranged inside the switching mechanism is therefore heated indirectly from the outside. This external heating leads to a regular switching operation of the switching mechanism, which does not cause any damage to the switching mechanism itself. Heating by means of an external heat source is possible with a comparatively low energy consumption in a cost-effective and automated manner.

Preferably, the temperature to which the switching mechanism is heated in method step (ii) is higher than 100° C. Particularly preferably, the switching mechanism is heated to a temperature higher than 150° C. in method step (ii).

This ensures that the temperature-dependent switching mechanism is brought into its open state without any doubt before performing method step (iii).

In a further refinement, it is preferred that the switching mechanism is heated to the assembly temperature above the response temperature by passing the switch housing and the switching mechanism arranged therein in an automated manner through a heating section.

Such a heating section can, for example, be designed as a heating tunnel through which the switch housing automatically passes. In this way, the switch housing can be heated continuously and thus harmlessly. Such a heating section can also be integrated into an automated production or assembly line without great effort.

The attachment of the first external terminal by material-locking joining with the application of heat is preferably performed automatically after passing through the heating section.

In a further refinement, the method comprises the following further step: (iv) attaching, by material-locking joining with the application of heat, a second external terminal to the second electrode or to a part electrically connected to the second electrode.

This additional step (iv) can take place before step (ii), i.e. before the switching mechanism is brought into its open state by external heating. This is possible, in particular, if the heat generated during the material-locking joining of the second external terminal does not have a too great damaging effect on the switching mechanism arranged inside the switch housing. This, in turn, is the case in particular if the second external terminal is attached at a point on the switch that is further away from the switching mechanism and/or is not in direct thermal contact with the switching mechanism.

However, this type of refinement is particularly advantageous for switches in which the two electrodes are arranged on opposite sides of the switch housing. In this case, it is often the case that the fragile components of the switching mechanism have a larger distance from the second electrode in the closed state than in the open state, while they have a larger distance from the first electrode in the open state than in the closed state.

If the second external terminal is attached to the second electrode or a component connected to the second electrode while the switching mechanism is in the closed state, and the first external terminal is attached to the first electrode or a component connected to the first electrode after the switching mechanism has been brought to its open state, the fragile components of the switching mechanism are as far away as possible from the respective joining point during both joining processes. The heat generated during the two joining processes thus has as little harmful effect as possible on the fragile components of the switching mechanism.

However, depending on the structure of the switch or the structure of the switching mechanism inside it, it can also be advantageous for both joining processes, i.e. the attachment of both external terminals, to take place after process step (ii), i.e. at a time when the switching mechanism is already in its open state.

In a further refinement, the switch housing comprises a lower part and a cover part which closes the lower part and is electrically insulated from the lower part, wherein the cover part is at least partially made of electrically conductive material, and wherein the first electrode is arranged on the cover part.

In this refinement, the cover part of the switch housing is preferably made of metal. Accordingly, the heat generated during the joining process during method step (iii) is particularly high, so that the method has a particularly advantageous effect.

The lower part can also be made of electrically conductive material, for example metal. An outer side of the cover part facing away from the inside of the switch housing and an outer side of the lower part facing away from the inside of the switch housing can be used as contact connections for the external terminals of the switch. The cover and lower part can therefore themselves form the connection electrodes of the switch.

The first electrode can comprise a contact part which extends from the inside of the switch housing through the cover part to the outside. This contact part can therefore be a type of piercing or shoot-through contact, which forms the first electrode on the inside and comprises a contact surface for the first external terminal on the outside. In such a case, the heat conduction that occurs between the joining point and the first electrode during joining during method step (iii) is particularly high, so that in this case it is particularly advantageous if the switching mechanism has already been brought into its open state in advance.

In a further refinement, the method comprising steps (i)-(iii) is repeated for a plurality of temperature-dependent switches, wherein the switch housings of the plurality of temperature-dependent switches are fixed to a common conveyor belt while steps (i)-(iii) are carried out.

This enables an automated assembly of the switch.

Preferably, the conveyor belt comprises a plurality of receptacles, to each of which one of the switch housings of the plurality of temperature-dependent switches is fixed, wherein each of the plurality of receptacles comprises a connecting piece which is electrically connected to the second electrode of the respective switch housing and to which the second external terminal is attached by material-locking joining with the application of heat.

This connecting piece enables a very simple way of attaching the second external terminal. The receptacles provided on the conveyor belt, which are preferably ring-shaped, are therefore not only used to transport the switches, but also to simplify the joining process for attaching the second external terminal to the individual switches.

In a further refinement, the temperature-dependent switching mechanism comprises a bimetal part.

In the present context, a bimetal part is understood to be a multi-layered, active, sheet-shaped device comprising two, three or four inseparably connected components with different coefficients of thermal expansion. The connection of the individual layers of metals or metal alloys is materially or positively locking and is achieved, for example, by rolling.

Bimetal parts such as these comprise a first geometric conformation in their low-temperature state and a second geometric conformation in their high-temperature state, between which they switch in a hysteresis-like manner depending on the temperature. When the temperature changes above the response temperature or below their reset temperature, such bimetal parts snap into the other conformation.

In a further refinement, the temperature-dependent switching mechanism comprises a spring part interacting with the bimetal part.

The bimetal part is preferably a temperature-dependent bimetallic snap-action disc. The spring part is preferably a temperature-independent snap-action spring disc.

Further features and advantages are apparent from the accompanying drawings and the description hereinafter.

It is to be understood that the features mentioned above and those to be explained below can be used not only in the combination indicated in each case, but also in other combinations or on their own, without departing form the scope of the present disclosure.

DESCRIPTION OF PREFERRED EMBODIMENTS

FIGS.1and2show an exemplary temperature-dependent switch that can be assembled with the herein presented method. The switch is denoted in its entirety with the reference numeral10.

FIG.1shows the low temperature state of switch10.FIG.2shows the high temperature state of switch10.

It is understood that the switch10shown inFIGS.1and2is only one example of various possible temperature-dependent switches that can be assembled with the method. However, the manufacturing or assembly method can in principle also be used for various other temperature-dependent switches that have a different design than the switch10shown inFIGS.1and2. However, the switch10shown inFIGS.1and2is described in the following as an example of a possible temperature-dependent switch in order to explain the basic structure and function of such a temperature-dependent switch.

The switch10comprises a switch housing12, inside which a temperature-dependent switching mechanism14is arranged. The switch housing12comprises a pot-like lower part16and a cover part18, which is held on the lower part16by a bent or flanged upper edge20of the lower part16.

In the example of the switch10shown inFIGS.1and2, both the lower part16and the cover part18are made of an electrically conductive material, preferably metal. An insulating foil22is arranged between the lower part16and the cover part18. The insulating foil22provides electrical insulation of the lower part16from the cover part18. Likewise, the insulating foil22provides a mechanical seal that prevents liquids or contaminants from entering the interior of the switch housing12from the outside.

Since the lower part16and the cover part18in this example are each made of electrically conductive material, thermal contact to an electrical device to be protected can be made via their outer surfaces. The outer surfaces also serve as the electrical external terminal of the switch10. For example, a first electrical external terminal can be attached to the switch10on the outer surface24of the cover part18and a second electrical external terminal can be attached to the outer surface26of the lower part16.

A further insulation layer28is arranged on the outside of the cover part18in the example of the switch10shown inFIGS.1and2.

The switching mechanism14is clamped between the lower part16and the cover part18. The switching mechanism14comprises a bimetal part30, a spring part32and a movable contact part34.

The bimetal part30comprises a temperature-dependent bimetallic snap-action disc with a central opening provided therein, with which the bimetallic snap-action disc is slipped over the movable contact part34.

The spring part32comprises a temperature-independent snap-action spring disc, which is also fitted over the movable contact part34with a centric opening provided therein, but from an opposite bottom side. The two snap-action discs30,32are thus fitted over the movable contact part34from opposite sides.

In the low-temperature state of the switch10shown inFIG.1, the snap-action spring disc32supports the movable contact part34from below by pressing with its inner edge area36from below against a circumferential, annular collar38of the movable contact part34. Here, the snap-action spring disc32is supported with its outer, circumferential edge42on the inner base44of the lower part16.

In this state of the switch10, the inner edge region40of the bimetallic snap-action disc30preferably rests freely on this collar38of the movable contact part34from the opposite top side. The outer, circumferential edge46of the bimetallic snap-action disc30hangs freely into the interior of the housing12. In this type of switch10, the bimetallic snap-action disc30is thus stored in the switch housing12almost force-free in the low-temperature state, without being firmly clamped therein.

In the low-temperature state of the switch10shown inFIG.1, the temperature-dependent switching mechanism14establishes an electrically conductive connection between the two electrodes50,52of the switch10by pressing the movable contact part34against a stationary contact part48arranged on the cover part18. The contact pressure with which the movable contact part34is pressed against the stationary contact part48in the low-temperature state of the switch10is effected in the switch10by the snap-action spring disc32.

Parts of the switch housing12function here as electrodes50,52, between which the temperature-dependent switching mechanism14establishes the electrically conductive connection in the low-temperature state of the switch10. More precisely, in the herein shown switch10, the stationary contact part48functions as the first electrode50and the lower part16of the switch housing12or the inner bottom44of the lower part16functions as the second electrode52.

If, starting from the low-temperature state of the switch10shown inFIG.1, the temperature of the device to be protected and thus the temperature of the switch10and the bimetallic snap-action disc30arranged therein increases to the response temperature of the switching mechanism14, which corresponds to the response temperature of the bimetallic snap-action disc30, or above this response temperature, the bimetallic snap-action disc30snaps from its convex low-temperature configuration shown inFIG.1into its concave high-temperature configuration, which is shown inFIG.2. During this snap-action, the bimetallic snap-action disc30is supported with its outer edge46on the bottom side54of the cover part18. With its center or its inner edge area40, the bimetallic snap-action disc30thereby presses the movable contact part34downwards and lifts the movable contact part34off the stationary contact part48. As a result, the spring snap-disc32simultaneously bends downwards at its center, so that the spring snap-disc32snaps over from its first geometric configuration shown inFIG.1into its second geometric configuration shown inFIG.2. The electrically conductive connection between the two electrodes50,52of the switch10previously established via the switching mechanism14is thus interrupted.

The temperature-dependent switching mechanism14is thus configured to establish and disconnect the electrically conductive connection between the two electrodes50,52in a temperature-dependent manner. Below the response temperature of the bimetallic snap-action disc30, the switching mechanism14is in its low-temperature state shown inFIG.1, in which it establishes the electrically conductive connection between the two electrodes50,52. As soon as the response temperature of the bimetallic snap-action disc30is exceeded, the bimetallic snap-action disc30brings the switching mechanism14into the high-temperature state shown inFIG.2, in which the electrically conductive connection between the two electrodes50,52is interrupted.

FIG.5shows schematically, in the form of a simplified flow chart, steps for the manufacture/assembly of such a temperature-dependent switch10. In the first step S101, the switch housing12with the switching mechanism14arranged therein is provided. This first step S101comprises inserting the switching mechanism14into the switch housing12and closing the switch housing12in order to produce the assembly state of the switch10shown inFIGS.1and2.

Subsequently, in step S102, the switching mechanism14is intentionally heated to an assembly temperature above the response temperature of the bimetallic snap-action disc30to bring the switching mechanism14into its open state shown inFIG.2. In this open state of the switching mechanism14, the first external terminal is then fixed to the first electrode50of the switch10in step S103.

FIG.3schematically shows the sequence of this assembly process using the example of an automated assembly, in which a plurality of such temperature-dependent switches10are mounted one after the other on a movable conveyor belt56. The first method step S101of providing the switch housing12with the switching mechanism14arranged therein is not explicitly shown inFIG.3, as this can be realized in a conventional automated or manual way.FIG.3visualizes in particular the assembly process during the method steps S102and S103.

In the assembly process shown schematically inFIG.3, the individual switches10with their respective switch housings12are each fixed individually to the conveyor belt56in order to prevent the switches10from slipping or even getting lost. Preferably, the switches10are fixed to the conveyor belt56in a material-locking manner. For this purpose, the conveyor belt56comprises a plurality of receptacles58, as can be seen in particular inFIG.4, in which the conveyor belt56is shown in a top view from above without the switches10inserted therein.

The receptacles58are annular receptacles into which the switches10are inserted from above. Particularly preferably, the receptacles58are adapted to the diameters of the lower parts16of the switch housings12. As shown inFIGS.1and2, the lower part16of each switch10comprises a recessed, circumferential shoulder60on the bottom side, into which the annular receptacle58is fitted and is preferably soldered or welded thereto.

In addition, each of the receptacles58comprises a connecting piece62which, as explained in detail hereinafter, essentially serves to attach the second external terminal of the respective switch10.

During the assembly process, the conveyor belt56is moved in the direction of arrow64, so that the switches10fixed in the conveyor belt56pass through the individual assembly steps explained hereinafter.

First, the second external terminal66, which is provided as a cable lug, a connection lug, a connection cable or a stranded wire, is connected to the second electrode52of the switch10in an electrically conductive manner. For this purpose, the second external terminal66is welded or soldered to the connecting piece62, which in turn is fixed to the lower part16or the second electrode52. This is indicated schematically inFIG.3by means of a first welding gun68.

The second external terminal66is attached in the low-temperature state of the switch10. This has the advantage that the greatest possible distance is thus maintained between the movable contact part34of the switching mechanism14and the welding point to which the second external terminal66is attached. The risk of the movable contact part34fusing with the stationary contact part48due to the heat thereby generated is thus reduced to a minimum.

The switches10are then brought into the high-temperature state by external heating, in which the respective switching mechanism14is in its open state shown inFIG.2. This is done in the present case by passing the switches10through a heating tunnel or heating section70. One or more external heat sources72are provided on this heating section70, which are illustrated schematically inFIG.3by heating wires. However, it will be understood that the heat sources72can be any type of heat source, for example hot air heat sources, infrared heat sources, inductive heat sources, etc.

Preferably, the switches within the heating section70are continuously heated to an assembly temperature above the switching mechanism response temperature by means of the heat sources72. Typically, heating to a temperature higher than 100° C. is sufficient for this purpose, for example heating to a temperature in the area of 150-270° C.

After passing through the heating section70, the switching mechanisms14of all switches10are accordingly in their open or high temperature state. While the switching mechanisms14of the switches10are in this open state, the first external terminal74, which is also provide as a cable lug, a connection strand, a regular cable or a connection lug, is welded or soldered to the top side of the stationary contact part48, which functions as the first electrode50, as shown in the right-hand edge ofFIG.3. This process is illustrated schematically inFIG.3by means of a second welding gun76.

As can be seen particularly inFIG.2, the movable contact part34of the switching mechanism14has a maximum distance from the stationary contact part48in the open state. In addition, there is no direct mechanical or thermal contact between the two contact parts34,48. Accordingly, the risk of the two contact parts34,48fusing together due to the heat generated when the first external terminal74is attached is reduced to a minimum. The fragile components30,32,34of the switching mechanism14are thus protected in the best possible way from damage that can otherwise occur due to the extremely high heat development inside the switch housing12.

The method thus enables an automated assembly/manufacture of temperature-dependent switches, which enables a stable and sustainable attachment of the external terminals74,66and at the same time protects the temperature-dependent switching mechanism14provided in the switch in the best possible way.

As already mentioned, the assembly method is suitable not only for a temperature-dependent switch10as shown schematically inFIGS.1and2, but also for various other temperature-dependent switches with similar/comparable switching properties.