EP4322193A1 - Temperature-dependent switch - Google Patents

Abstract

Temperature-dependent switch (100), comprising a temperature-dependent switching mechanism (10) with a switching mechanism unit (14) which has a movable contact part (22) coupled to a bimetal snap-action disk (18), and with a switching mechanism housing (16) in which the Rear derailleur unit (14) is arranged and held captively therein. Furthermore, the switch (100) has a switch housing (12) in which the switching mechanism housing (16) is arranged and captively held therein, the switch housing (12) having a stationary contact part (32) which acts as a mating contact to the movable contact part ( 22) functions. The rear derailleur housing (16) has an electrically conductive first base body (36) and the rear derailleur (10) is designed to hold the switch (100) in a low-temperature position below a response temperature of the bimetal snap disk (18), in which the rear derailleur (10) establishes a first electrical connection between the first base body (36) and the stationary contact part (32) via the movable contact part (22), and when the response temperature is exceeded, bringing the switch (100) into a high-temperature position in which the Switching mechanism (10) interrupts the first electrical connection. The switch (100) also has a PTC component (46) which is electrically connected in parallel to the first electrical connection.

Description

The present invention relates to a temperature-dependent switch.

A variety of temperature-dependent switches are generally already known. An exemplary temperature-dependent switch is in the DE 10 2013 102 006 A1 disclosed.

Such temperature-dependent switches are used in a manner known per se to monitor the temperature of a device. For this purpose, the switch is brought into thermal contact with the device to be protected, for example 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 in 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 switch.

The one from the DE 10 2013 102 006 A1 Known switch has a switch housing, in the interior of which a switching mechanism is arranged in a hermetically sealed manner. The switch housing is constructed in two parts. It has a lower part made of electrically conductive material and a cover part that is made of an insulating material or a thermistor material (PTC material). The cover part is inserted into the lower part and is held by an upper bent edge of the lower part. The rear derailleur is arranged clamped between the cover part and the lower part. When the switch is manufactured, the rear derailleur is initially inserted loosely into the lower part. The lid part is then placed on top and firmly connected to the lower part.

The temperature-dependent switching mechanism arranged in the switch housing has a bimetal snap disk which is attached to a movable contact part. This bimetal snap-action disk is responsible for the temperature-dependent switching behavior of the switch. It ensures that, at low temperatures, the switching mechanism establishes an electrically conductive connection between the movable contact part of the switching mechanism and a stationary contact part arranged on the cover part, which acts as a mating contact to the movable contact part. At higher temperatures, however, the bimetal snap disk interrupts this electrical contact by ensuring that the movable contact part is lifted off the stationary contact part.

The bimetal snap disk is usually designed as a multi-layer, active, sheet-metal component made of two, three or four interconnected components with different thermal expansion coefficients. The connections of the individual layers made of metals and metal alloys in such bimetal snap disks are usually cohesive or form-fitting and are achieved, for example, by rolling.

Such a bimetal snap-action disk has a first stable geometric configuration (low-temperature configuration) at low temperatures, below the response temperature of the bimetal snap-action disk, and a second stable geometric configuration (high-temperature configuration) at high temperatures, above the response temperature of the bimetal snap-action disk. Depending on the temperature, the bimetal snap-action disk switches from its low-temperature configuration to its high-temperature configuration in the manner of hysteresis. This process is often referred to as "snapping", which is also why it is called a "snapping disk".

If no switch-back lock is provided, the bimetal snap-action disk snaps back into its low-temperature configuration so that the switch is closed again when the temperature of the bimetal snap-action disk drops below the so-called return temperature of the bimetal snap-action disk as a result of the device to be protected cooling down.

However, depending on the application, such a downshift may be undesirable. For safety reasons, for example, it may be necessary for the switch to be designed in such a way that, after the switch has been opened due to temperature, it does not automatically close again when the device to be protected cools down again. For example, the switch should only be able to be closed again after the device to be protected has not only cooled down, but has also been completely disconnected from the power supply.

A so-called self-holding function was developed for such cases. With the one from the DE 10 2013 102 006 A1 In a known switch, this self-holding or self-holding function is caused by the fact that the cover part of the switch is made of a PTC material (Positive Temperature Coefficient Thermistor or PTC thermistor).

As long as the switch is in its low temperature position and is closed, no current flows through the PTC material connected as a parallel resistor. However, when the switch opens, a small self-holding current flows through the parallel resistor, which heats it up and ensures that the switch remains at a temperature above the response temperature of the bimetal snap-action disk. The self-holding current is so low that the electrical device being protected does not suffer any further damage, allowing it to cool down. The self-holding resistance, which is caused by the PTC element, prevents the switch itself from cooling down and switching on again, which would lead to an iterative switching on and off of the electrical device to be protected without the parallel resistor.

The one from the DE 10 2013 102 006 A1 Known switch has a manufacturing-related disadvantage. This disadvantage is due to the fact that the bimetal snap-action disk is inserted into the switch housing as a loose individual part together with the movable contact part. Only by closing the switch housing is the bimetal snap disk then fixed in position and its position relative to the other components of the rear derailleur is determined. However, the position of such a switch, in which the bimetal snap-action disk is inserted individually, has proven to be relatively complicated, since several steps are necessary to insert the switching mechanism into the switch housing.

In addition, storing the rear derailleur or the individual parts of the rear derailleur is cumbersome. For example, bulk storage of the individual rear derailleur parts is hardly an option since these individual parts, especially the bimetal snap disk, are relatively susceptible to damage. If such damage occurs during storage, the resulting malfunction of the rear derailleur is usually only recognized when the switch is assembled, since a functional test of the rear derailleur is hardly possible beforehand.

It is therefore an object of the present invention to provide a temperature-dependent switch with a self-holding function that is easier to produce overall. Among other things, it would be desirable if the rear derailleur could be pre-produced as a semi-finished product without being susceptible to damage. Furthermore, it would be desirable if a functional test were possible with the rear derailleur before it is finally installed in the switch. Furthermore, the switch should be comparatively easy to install, have a low overall height and be designed to be pressure-stable.

• ein temperaturabhängiges Schaltwerk mit einer Schaltwerkseinheit, die ein mit einer Bimetall-Schnappscheibe gekoppeltes, bewegliches Kontaktteil aufweist, und mit einem Schaltwerksgehäuse, in dem die Schaltwerkseinheit angeordnet und darin unverlierbar gehalten ist; und
• ein Schaltergehäuse, in dem das Schaltwerksgehäuse angeordnet und darin unverlierbar gehalten ist, wobei das Schaltergehäuse ein stationäres Kontaktteil aufweist, das als Gegenkontakt zu dem beweglichen Kontaktteil fungiert;

• wobei das Schaltwerksgehäuse die Schaltwerkseinheit von einer ersten Gehäuseseite, einer der ersten Gehäuseseite gegenüberliegenden zweiten Gehäuseseite und einer zwischen und quer zu der ersten und der zweiten Gehäuseseite verlaufenden Gehäuseumfangsseite umgibt und auf der ersten Gehäuseseite eine Öffnung aufweist, durch die das bewegliche Kontaktteil mit dem stationären Kontaktteil zusammenwirkt,
• wobei das Schaltwerksgehäuse einen elektrisch leitfähigen ersten Grundkörper aufweist und das Schaltwerk dazu eingerichtet ist, unterhalb einer Ansprechtemperatur der Bimetall-Schnappscheibe den Schalter in einer Tieftemperaturstellung zu halten, in der das Schaltwerk über das bewegliche Kontaktteil eine erste elektrische Verbindung zwischen dem ersten Grundkörper und dem stationären Kontaktteil herstellt, und bei Überschreiten der Ansprechtemperatur, den Schalter in eine Hochtemperaturstellung zu bringen, in der das Schaltwerk die erste elektrische Verbindung unterbricht, und
• wobei der Schalter ferner ein PTC-Bauteil aufweist, das elektrisch parallel zu der ersten elektrischen Verbindung geschaltet ist.

This object is achieved according to the invention by a temperature-dependent switch, which comprises the following components:

• a temperature-dependent switching mechanism with a switching mechanism unit which has a movable contact part coupled to a bimetal snap-action disk, and with a switching mechanism housing in which the switching mechanism unit is arranged and captively held therein; and
• a switch housing in which the switching mechanism housing is arranged and captively held therein, the switch housing having a stationary contact part which functions as a mating contact to the movable contact part;

• wherein the rear derailleur housing surrounds the rear derailleur unit by a first housing side, a second housing side opposite the first housing side and a housing peripheral side running between and transversely to the first and second housing sides and has an opening on the first housing side through which the movable contact part communicates with the stationary contact part interacts,
• wherein the switching mechanism housing has an electrically conductive first base body and the switching mechanism is designed to hold the switch in a low-temperature position below a response temperature of the bimetal snap-action disk, in which the switching mechanism establishes a first electrical connection between the first base body and the stationary one via the movable contact part Contact part is established, and when the response temperature is exceeded, the switch is brought into a high-temperature position in which the switching mechanism interrupts the first electrical connection, and
• wherein the switch further comprises a PTC component which is electrically connected in parallel to the first electrical connection.

Similar to the one from the DE 10 2013 102 006 A1 known switches, the switch according to the invention also has a PTC component (thermistor component) which is electrically connected in parallel to the switching mechanism unit. More precisely, the PTC component is electrically connected in parallel to the first electrical connection, which is effected by the switching mechanism in the low-temperature position of the switch. The PTC component thus fulfills a self-holding function of the switch, which keeps the switch in its high-temperature position after a single, temperature-related opening, in which the switching mechanism is The first electrical connection is interrupted when the device to be protected by the switching mechanism cools down again. In the high-temperature position of the switch, the current flows through the PTC component, which is heated up as a result. The resulting heat leads, as in the case of the DE 10 2013 102 006 A1 known switch means that the rear derailleur does not cool down and therefore does not close the switch again or bring it into its low temperature position.

In contrast to the one from the DE 10 2013 102 006 A1 known switch, however, the switch according to the invention is constructed much more simply. In particular, its assembly can be carried out more easily and in fewer steps.

The switch according to the invention comprises a switching mechanism which has an additional switching mechanism housing in which the switching mechanism unit, which has the bimetal snap disk and the movable contact part, is captively held. The rear derailleur housing surrounds the rear derailleur unit both from a first housing side and from a second housing side opposite the first housing side, as well as from a housing peripheral side that runs between and transversely to the first and second housing sides. The rear derailleur housing thus at least partially surrounds the rear derailleur unit from all six spatial directions, so that the rear derailleur cannot fall out of the rear derailleur housing.

The rear derailleur can therefore be pre-produced as a semi-finished product, including the rear derailleur unit and including the rear derailleur housing surrounding the rear derailleur unit, before it is inserted into the switch housing. The rear derailleur, pre-produced as a semi-finished product, can be kept in stock as bulk goods. During this bulk storage, the various components of the switching mechanism unit, in particular the bimetal snap disk and the movable contact part, are protected by the switching mechanism housing. Damage to these various components during storage of bulk goods is largely ruled out since the various components of the switching mechanism are securely encapsulated in the switching mechanism housing.

However, the rear derailleur housing not only offers the advantage of safely storing the rear derailleur unit arranged therein, it also enables a much simpler way of producing the temperature-dependent switch. Unlike a conventional switch housing, the rear derailleur housing that is now additionally provided is not a closed housing in which the rear derailleur is hermetically sealed, but rather a partially open housing that has an opening on the first side of the housing through which the movable contact part of is accessible outside the rear derailleur housing. The rear derailleur, together with the rear derailleur housing, can thus be inserted as a unit into a simplified switch housing, which forms the final switch housing.

When producing the temperature-dependent switch, the switching mechanism according to the invention, together with its switching mechanism housing, can first be pre-produced as a semi-finished product and then inserted as a whole into the switch housing. This not only simplifies the storage of the switching mechanism, but also the production of the temperature-dependent switch many times over.

As already mentioned, the rear derailleur housing is a partially open housing. While the second housing side and the housing peripheral side of the rear derailleur housing are preferably each closed housing sides, the first housing side is only a partially closed or a partially opened housing side due to the opening mentioned.

The partially opened first side of the rear derailleur housing is covered by the switch housing, which acts as the lower part of the switch. The movable contact part interacts through the opening in the switching mechanism housing directly with the stationary contact part, which is arranged on the switch housing. In the low temperature position of the switch, the movable contact part touches the stationary contact part through the opening in the switching mechanism housing.

Overall, this creates a switch that is simply constructed from relatively few components and can be produced in comparatively few steps. This in The rear derailleur used for the switch can be pre-produced together with the rear derailleur housing and kept in stock as bulk goods. The housing of the switch, which is made up of the switch housing and the switching mechanism housing, is constructed to be comparatively pressure-stable and can still be designed to be relatively compact/space-saving. With the help of the PTC component, a self-holding function of the switch is implemented, which prevents the switch from switching back to the low-temperature position after switching to the high-temperature position once, as long as a voltage is applied to the switch or to the device to be protected by the switch.

The above-mentioned task is therefore completely solved.

According to one embodiment, the PTC component is arranged in the switch housing.

This not only has the advantage of a compact switch design, but also the advantage that the PTC component is ideally protected inside the switch.

According to a further embodiment, the switch housing has an electrically conductive second base body which is connected to the first base body via the PTC component, the second base body surrounding the first housing side and the housing peripheral side of the switching mechanism housing.

The rear derailleur housing is preferably made of an electrically conductive material. In other words, the first base body preferably forms the rear derailleur housing.

The switch housing is preferably made of an electrically conductive material. In other words, the second base body preferably forms the switch housing.

Both the switch housing and the rear derailleur housing can therefore function as external electrical connections of the switch. As long as the switch is in its low-temperature position, the current flows from the switch housing via the switching derailleur into the switching derailleur housing or in the opposite direction from the switching derailleur housing via the switching derailleur into the switch housing.

When the switch is open, i.e. in the high-temperature position of the switch, the first electrical connection is interrupted by the switching mechanism, so that the electrical current between the switch housing and the switching mechanism housing can only flow via the PTC component.

Since the PTC component is already heated in this case, it has a relatively high resistance, so that only a very small self-holding current can flow through the PTC component and thus through the switch. At the same time, the PTC component heats up further, so that the switch is kept in its high-temperature position.

According to a further embodiment, the switching mechanism housing rests on the PTC component with its first housing side.

Preferably, the first side of the switching mechanism housing rests on the PTC component from above. The PTC component forms an intermediate layer that is arranged between the switch housing and the switch housing. This ensures a very compact and extremely pressure-stable design of the switch.

According to a further embodiment, the electrically conductive first base body of the rear derailleur housing forms at least part of the second housing side of the rear derailleur housing. This part of the second side of the housing forms a freely accessible outside of the switch.

The said part of the first base body, which forms part of the second housing side of the switching mechanism housing, is not surrounded by the switch housing when the switch is fully assembled. This part of the switchgear housing can therefore serve as the direct external electrical connection surface of the switch.

The mentioned part of the first base body of the switching mechanism housing, which forms a freely accessible outside of the switch, preferably has an outwardly curved, dome-shaped or cup-shaped section. This dome or cup-shaped section of the rear derailleur housing preferably protrudes at least partially from the switch housing. At this point, “curved outwards” means that the dome or cup-shaped section is curved outwards from the perspective of the switch housing, i.e. outwards from the inside of the switch housing. The outside of the switch is convexly curved at this point.

This design of the rear derailleur housing makes the switch extremely pressure-stable. In addition, the dome or cup-shaped section can be used very easily as an external connection surface of the switch.

According to a further embodiment, the switching mechanism housing is designed in one piece.

The rear derailleur housing is therefore very simple and consists of just one part. It is preferably made of metal. This metal forms the electrically conductive first base body, which at least partially surrounds the switching mechanism unit from all sides and has the opening already mentioned on the first side of the housing.

According to a further embodiment, the temperature-dependent switch further has an insulator which is arranged between the first base body and the second base body and rests on the first base body and on the second base body.

This insulator electrically isolates the two base bodies from each other. The insulator ensures that an electrically conductive connection is established between the two base bodies in the low-temperature position of the switch via the switching mechanism unit. In the high-temperature position of the switch, the two electrically conductive base bodies are only connected to one another via the PTC component, otherwise they are electrically insulated from one another.

According to a further embodiment, the insulator has an annular body, the inside of which rests on the peripheral side of the switching mechanism housing and the outside of which rests on an inner peripheral surface of the switch housing.

The insulator is preferably designed as a ring body. This ring body can be designed in the shape of a circular ring when viewed from above. However, when viewed from above, the ring body can in principle also have a polygonal outer contour.

The term “ring body” is therefore to be understood generally. It refers to any body that has a circumferentially closed contour. For example, the outer contour viewed in the top view can also be elliptical or have any free shape. The ring body does not necessarily have to be hollow cylindrical or toroidal, although this is preferred.

The design of the insulator as a ring body has the advantage that the insulator electrically insulates the switching mechanism housing along the entire circumference from the switch housing. In addition, such an annular body can be arranged in the switch housing to save space. The ring body is also preferably designed to be solid, so that the insulator forms a mechanically stable component of the switch, which can also serve to support other components of the switch and is easy to handle during assembly of the switch. The ring body of the insulator thus automatically ensures a correct alignment of the switching mechanism, in particular the associated movable contact part, relative to the stationary contact part, which is arranged on the switch housing.

The underside of the ring body of the insulator preferably rests on the PTC component. When assembling the switch, the ring body of the insulator is preferably placed on the PTC component before the switching mechanism housing is inserted into the switch housing. As already mentioned, it ensures that the rear derailleur housing is correctly aligned relative to the switch housing during assembly.

According to a further embodiment, a diameter of the opening is smaller than a diameter of the bimetal snap-action disk measured parallel thereto.

The bimetal snap-action disk is therefore held securely in the rear derailleur housing and cannot come out of it even if there is a corresponding shock.

According to a further embodiment, the bimetal snap-action disk is designed to snap from a geometrically stable low-temperature configuration to a geometrically stable high-temperature configuration when the response temperature is exceeded, the bimetal snap-action disk being supported in its high-temperature configuration on a support surface arranged on the first housing side of the switching mechanism housing is formed on the first base body, and thereby keeps the movable contact part at a distance from the stationary contact.

Since the rear derailleur unit according to the present invention is encapsulated in the rear derailleur housing and the bimetal snap disk is supported in its high-temperature configuration on the said support surface inside the rear derailleur housing, a functional check of the rear derailleur can also be carried out on the rear derailleur pre-produced as a semi-finished product, i.e. before The rear derailleur is installed in the switch housing and the switch is completely assembled. The bimetal snap disk can then assume its two temperature-dependent configurations inside the rear derailleur housing.

This is not possible with conventional switches because the bimetal snap-action disk is supported in its high-temperature configuration on the switch housing due to the lack of the switch housing, which is now specially provided, so that a functional check is only possible when the switch is fully assembled.

According to a further embodiment, the switching mechanism unit further has a spring snap disk coupled to the movable contact part, which is supported in the low-temperature position of the switch on an inner surface arranged on the second housing side inside the switching mechanism housing. This inner surface is preferably an inner surface of the electrically conductive first base body of the switching mechanism housing.

The additional provision of such a spring snap-action disk has the particular advantage that the bimetal snap-action disk is thereby relieved. In the low temperature position of the switch, i.e. when the circuit above the switch is closed, is used the spring snap disk according to this embodiment as a current-carrying component. The bimetal snap-action disk, however, is then not a current-carrying component.

In addition, in the low-temperature position of the switch, the spring snap disk generates the closing pressure with which the movable contact part is pressed against the stationary contact part. The bimetal snap-action disk can, however, be mounted with almost no force in the low-temperature position of the switch. This has a positive effect on the service life of the bimetal snap-action disk and ensures that the switching point, i.e. the response temperature of the bimetal snap-action disk, does not change even after many switching cycles.

According to a further embodiment, a circumferential space between the switching mechanism housing and the switch housing is filled with insulating compound. The insulating compound is preferably a varnish which is used to fill the space between the switching mechanism housing and the switch housing.

This seals the inside of the switch, where the rear derailleur is located, extremely well. In addition, the insulating and sealing compound ensures a mechanically stable attachment of the rear derailleur housing in the switch housing.

It is understood that the features mentioned above and to be explained below can be used not only in the combination specified in each case, but also in other combinations or alone, without departing from the scope of the present invention.

Fig. 1

eine schematische Schnittansicht des temperaturabhängigen Schalters gemäß einem Ausführungsbeispiel der vorliegenden Erfindung, wobei der Schalter in seiner Tieftemperaturstellung gezeigt ist; und

Fig. 2

eine schematische Schnittansicht des in Fig. 1 gezeigten Schalters, wobei der Schalter in seiner Hochtemperaturstellung gezeigt ist.

An exemplary embodiment of the invention is shown in the drawings and is explained in more detail in the following description. Show it:

Fig. 1

a schematic sectional view of the temperature-dependent switch according to an embodiment of the present invention, the switch being shown in its low-temperature position; and

Fig. 2

a schematic sectional view of the in Fig. 1 switch shown, the switch being shown in its high temperature position.

Fig. 1-2 show an exemplary embodiment of the switch according to the invention, each in a schematic sectional view. The switch is marked in its entirety with the reference number 100.

The switch 100 has a temperature-dependent switching mechanism 10, which is arranged in an electrically conductive switch housing 12.

The rear derailleur 10 has a functional rear derailleur unit 14 and a rear derailleur housing 16 surrounding this rear derailleur unit 14. The rear derailleur housing 16 at least partially surrounds the rear derailleur unit 14 from all six spatial directions.

As explained in detail below, the rear derailleur housing 16 is designed as a partially open housing, so that the rear derailleur unit 14 is accessible from at least one spatial direction, preferably from only one spatial direction, from outside the rear derailleur housing 16.

Due to the fact that the rear derailleur housing 16 at least partially surrounds the rear derailleur unit 14 from all six spatial directions, the rear derailleur unit 14 is held captively in the rear derailleur housing 16. The rear derailleur unit 14 cannot therefore be removed from the rear derailleur housing 16.

As long as the rear derailleur 10 is not installed in the switch 100 or its switch housing 12, there is preferably a certain amount of play between the rear derailleur unit 14 and the rear derailleur housing 16. In the in Fig. 1 However, in the installed state of the switch 100 shown, the switching mechanism unit 14 is firmly clamped. In the in Fig. 1 In the low temperature position of the switch 100 shown, the switching mechanism unit 14 is clamped between the switch housing 12 and the switching mechanism housing 16.

The rear derailleur unit 14 is constructed in three parts according to the present exemplary embodiment. The switching mechanism unit 14 has a temperature-dependent bimetal snap-action disk 18, a temperature-independent spring snap-action disk 20 and a movable contact part 22. The bimetal snap disk 18 and the spring snap disk 20 are held captively on the contact part 22. The rear derailleur unit 14 can thus be pre-produced as a semi-finished product and then inserted as a whole into the rear derailleur housing 16.

The rear derailleur 10 together with the rear derailleur unit 14 and the rear derailleur housing 16 also form a semi-finished product for the later produced temperature-dependent switch 100. Since both the three components 18, 20, 22 of the rear derailleur unit 14 are captively connected to one another, as is the rear derailleur unit 14 in the rear derailleur housing 16 is held captively, the switching mechanism 10 can be kept in storage as bulk material until it is installed in the temperature-dependent switch 100.

The rear derailleur housing 16 surrounds the rear derailleur unit 14 by a first housing side 24, a second housing side 26 opposite the first housing side 24 and a housing peripheral side 28 running between and transversely to the first and second housing sides 24, 26.

Preferably, the rear derailleur housing 16 completely surrounds the rear derailleur unit 14 from both the second housing side 26 and the housing peripheral side 28. The second housing side 26 and the housing peripheral side 28 therefore preferably form closed housing sides of the rear derailleur housing 16. Only the first housing side 24 is a partially open housing side of the rear derailleur housing 16.

In other words, the housing peripheral side 28 surrounds the switching mechanism unit 14 along the entire circumference, i.e. from a total of four spatial directions aligned orthogonally to one another. Furthermore, the switching mechanism housing 16 completely surrounds the switching mechanism unit 14 from a further spatial direction, namely from a spatial direction aligned orthogonally to the second housing side 26. Only from the sixth In the spatial direction, which is aligned orthogonally to the first housing side 24, the rear derailleur housing 16 only partially surrounds the rear derailleur unit 14.

On the first housing side 24, the rear derailleur housing 16 has an opening 30 through which the movable contact part 22 is accessible from outside the rear derailleur housing 16. Through this opening 30 in the rear derailleur housing 16, the movable contact part 22 of the rear derailleur 10 interacts with a stationary contact part 32. The stationary contact part 32 is arranged on an inside 34 of the switch housing 12.

In the in Fig. 1 In the exemplary embodiment shown, the stationary contact part 32 is formed in one piece with the switch housing 12. In principle, however, it would also be possible to provide the stationary contact part 32 as a type of rivet, which is connected to the switch housing 12 as a separate component. It is only important that an electrically conductive connection is established between the switch housing 12 and the stationary contact part 32.

A diameter D of the opening 30 is smaller than a diameter D ₂ of the bimetal snap-action disc 18 and/or the spring-action snap-action disc 20, measured parallel thereto. Thus, the movable contact part 22 is accessible from outside the switching mechanism housing 16 through the opening 30, However, the bimetal snap-action disk 18 and the spring-action snap-action disk 20 cannot detach or emerge from the rear derailleur housing 16.

The switching mechanism housing 16 has a base body 36 which is made of an electrically conductive material, for example metal. This base body 36 is referred to here as the “first base body”. In the exemplary embodiment shown here, the electrically conductive first base body 36 forms the entire switchgear housing 16. In this exemplary embodiment, the switchgear housing 16 is therefore designed in one piece from an electrically conductive material.

An upper part of the first base body 36, which forms the second housing side 26, simultaneously forms a freely accessible outside of the switch 100. The first housing side 24 and the housing peripheral side 28 are arranged completely inside the switch housing 12 and are therefore not accessible from outside the switch 100.

The switch housing 12 consists of an electrically conductive second base body 38. The second base body 38 is preferably also made of metal. The second base body 38 forms the lower part of the switch 100, in which the remaining components of the switch 100 are arranged.

The second base body 38 is preferably pot-shaped. An upper edge 40 of the raised, circumferential wall 42 of the second base body 38 of the switch housing 12 is folded or flanged towards the center of the switch 100 so that the switching mechanism 10 is captively held in the switch housing 12. The circumferential space between the switching mechanism housing 16 and the switch housing 12 is filled with an insulating compound 44. The insulating compound 44 is preferably an impregnating varnish that is poured into the space between the switch housing 12 and the switching mechanism housing 16 at the end of assembly of the switch 100.

On the one hand, the insulating compound 44 ensures that the switching mechanism housing 16 is fixed in the switch housing 12. On the other hand, the insulating compound 44 ensures a mechanical seal that prevents liquids or contaminants from outside from entering the interior of the switch 100. In this way, a sealed switch housing 12 is created, in which the switching mechanism housing 16 is held captively.

A PTC component 46 is also arranged in the switch housing 12. This PTC component 46 is a thermistor material whose electrical resistance increases with increasing temperature. The PTC component 46 is designed in the shape of a plate or disk. The PTC component 46 is inserted into the switch housing 12 and surrounds the stationary contact part 32.

The switchgear housing 16 rests flatly on the PTC component 46 with its first housing side 24. The electrically conductive first base body 36 of the switching mechanism housing 16 is thus connected to the electrically conductive second base body 38 of the switch housing 12 via the PTC component 46.

An insulator 48 rests on the PTC component 46. This insulator 48 is designed as an annular body 50, which is arranged between the first base body 36 of the switching mechanism housing 16 and the second base body 38 of the switch housing 12 and rests on both base bodies 36, 38. More precisely, the ring body 50 of the insulator 48 rests with its inside 52 on the housing peripheral side 28 of the switch housing 16 and with its outside 54 on an inner peripheral surface 56 of the switch housing 12.

The insulator 48 is preferably designed as a plastic insulator. In addition to its function of insulating the peripheral side 28 of the switching mechanism housing 16 from the inner peripheral surface 56 of the switch housing 12, the insulator 48 also ensures a correct alignment of the switching mechanism 10 relative to the switch housing 12 or of the switching mechanism 10 relative to the stationary contact part 32. The The shape of the annular body 50 of the insulator 48 is preferably adapted to the shape of the switch housing 12. The ring body 50 is therefore preferably designed as a circular ring.

Since the second base body 38 of the switch housing 12 and the first base body 36 of the switching mechanism housing 16 are each made of electrically conductive material, thermal contact can be established with a device to be protected via their outer surfaces.

The outer surfaces of the two base bodies 36, 38 also serve as the electrical connection of the switch 100. For example, the outside 58 of the second base body 38 of the switch housing 12 can function as a first electrical connection and the outside 60 of the first base body 48 of the switching mechanism housing 16 can function as a second electrical one Connection act. More specifically, the outside 60 of the Part of the base body 38 of the switching mechanism housing 16, which protrudes from the switch housing 12, acts as a second electrical connection.

This part of the switching mechanism housing 16, which forms a freely accessible outside of the switch 100, has a dome-shaped section 62 in the exemplary embodiment shown here. This dome-shaped section 62, the top of which is convex, ensures an extremely pressure-stable structure of the switch 100. Instead of a dome-shaped section 62, this section of the switching mechanism housing 16 can also be cup-shaped.

In the in Fig. 1 In the low temperature position of the switch 100 shown, the temperature-independent spring snap-action disk 20 is in its first configuration and the temperature-dependent bimetal snap-action disk 18 is in its low-temperature configuration. The spring snap disk 20 presses the movable contact part 22 against the stationary contact part 32, which acts as a counter contact. The switch 100 is now in its closed position, in which an electrically conductive connection between the outside 60 of the switching mechanism housing 16 and the outside 58 of the switch housing 12 via the spring snap disk 20, the movable contact part 22 and the stationary contact part 32.

The contact pressure between the movable contact part 22 and the stationary contact part 32 is generated by the spring snap disk 20. In the low-temperature position of the switch 100, the spring snap disk 20 is supported on an inner surface 64 arranged on the second housing side 26 inside the switching mechanism housing 16. In this state, however, the bimetal snap disk 18 is mounted in the rear derailleur housing 16 with almost no force.

If the temperature of the device to be protected and thus the temperature of the switch 100 and the bimetal snap-action disk 18 arranged therein increases to the switching temperature of the bimetal snap-action disk 18 or above this switching temperature, the bimetal snap-action disk 18 snaps from its position Fig. 1 shown concave low temperature configuration in their in Fig. 2 shown convex High temperature configuration. During this snapping, the bimetal snap disk 18 is supported with its outer edge 66 on a support surface 68 arranged on the first housing side 24 of the rear derailleur housing 16. As a result, at the same time the spring snap disk 20 bends upwards at its center, so that the spring snap disk 20 moves away from its in Fig. 1 shown, first stable geometric configuration in their in Fig. 2 shown, second geometrically stable configuration snapped around.

Fig. 2 shows the high temperature position of the switch 100, in which it is open. The electrically conductive connection between the switch housing 12 and the switching mechanism housing 16, which takes place in the low-temperature position of the switch 100 via the switching mechanism unit 14, is in the in Fig. 2 shown high temperature position of the switch 100 interrupted. The switch housing 12 is then “only” connected to the switching mechanism housing 16 via the PTC component 46.

In the high-temperature position of the switch 100, the PTC component 46 already has a relatively high electrical resistance due to the high temperature. Thus, only a small residual current can flow from the electrically conductive switch housing 12 via the PTC component 46 into the electrically conductive switching mechanism housing 16. This residual current is harmless to the device being protected. However, the residual current causes the PTC component 46 to heat up, causing the entire switch 100 to heat up. The bimetal snap disk 18 is therefore also kept at a temperature above its switching temperature, so that the switch 100 is no longer closed via the switching mechanism unit 14.

Only when the device to be protected is switched off, i.e. when no current flows through the switch 100, does the PTC component 46 and thus the entire switch 100 cool down. As soon as the switching mechanism unit 14 reaches a temperature below the response temperature of the bimetal snap-action disk 18, the bimetal snap-action disk 18 then snaps out of its position again Fig. 2 shown high temperature configuration in their in Fig. 1 shown low temperature configuration, whereby the switch 100 is closed again.

Finally, it should be noted that the spring snap washer 20 is not absolutely necessary. The rear derailleur unit 14 can also be implemented without a spring snap disk 20. In such a case, the switching mechanism unit 14 then “only” has the bimetal snap disk 18 and the movable contact part 22. The bimetal snap disk 18 then not only ensures the switching behavior of the switch 100, but also simultaneously generates contact pressure between the movable contact part 22 and the stationary contact part 32 in the low temperature position of the switch 100. The bimetal snap disk 18 is then used as a current-carrying component of the Rear derailleur 10 used.

Claims (14)

Temperature-dependent switch (100), comprising: - a temperature-dependent switching mechanism (10) with a switching mechanism unit (14), which has a movable contact part (22) coupled to a bimetal snap-action disk (18), and with a switching mechanism housing (16), in which the switching mechanism unit (14) is arranged and is held captively therein; and - a switch housing (12) in which the switching mechanism housing (16) is arranged and captively held therein, the switch housing (12) having a stationary contact part (32) which acts as a mating contact to the movable contact part (22); wherein the rear derailleur housing (16) extends the rear derailleur unit (14) from a first housing side (24), a second housing side (26) opposite the first housing side (24) and one extending between and transversely to the first and second housing sides (24, 26). Surrounds the peripheral side of the housing (28) and has an opening (30) on the first side of the housing (24), through which the movable contact part (22) interacts with the stationary contact part (32), wherein the rear derailleur housing (16) has an electrically conductive first base body (36) and the rear derailleur (10) is designed to hold the switch (100) in a low-temperature position below a response temperature of the bimetal snap-action disk (18), in which the rear derailleur (10) establishes a first electrical connection between the first base body (36) and the stationary contact part (32) via the movable contact part (22), and when the response temperature is exceeded, bringing the switch (100) into a high-temperature position in which the Switching mechanism (10) interrupts the first electrical connection, and wherein the switch (100) further has a PTC component (46) which is electrically connected in parallel to the first electrical connection. Temperature-dependent switch according to claim 1, wherein the PTC component (46) is arranged in the switch housing (12). Temperature-dependent switch according to claim 1 or 2, wherein the switch housing (12) has an electrically conductive second base body (38) which is connected to the first base body (36) via the PTC component (46), the second base body (38) the first housing side (24) and the housing peripheral side (28) of the rear derailleur housing (16) surrounds. Temperature-dependent switch according to one of the preceding claims, wherein the switching mechanism housing (16) rests with its first housing side (24) on the PTC component (46). Temperature-dependent switch according to one of the preceding claims, wherein the first base body (36) forms at least part of the second housing side (26) of the switching mechanism housing (16), this part of the second housing side (26) being a freely accessible outside (60) of the switch ( 100). Temperature-dependent switch according to claim 5, wherein the part of the second housing side (26) of the switching mechanism housing (16), which forms a freely accessible outside (60) of the switch (100), has an outwardly curved, dome or cup-shaped section (62). . Temperature-dependent switch according to one of the preceding claims, wherein the switching mechanism housing (16) is designed in one piece. Temperature-dependent switch according to claim 3, with an insulator (48) which is arranged between the first base body (36) and the second base body (38) and rests on the first base body (36) and on the second base body (38). Temperature-dependent switch according to claim 8, wherein the insulator (48) has an annular body (50) which rests with its inside (52) on the housing peripheral side (28) of the switching mechanism housing (16) and with its outside (54) on an inner circumferential surface of the switch housing (12) is present. Temperature-dependent switch according to 9, wherein the underside of the ring body (50) rests on the PTC component (46). Temperature-dependent switch according to one of the preceding claims, wherein a diameter of the opening (30) is smaller than a diameter of the bimetal snap-action disk (18) measured parallel thereto. Temperature-dependent switch according to one of the preceding claims, wherein the bimetal snap disk (18) is designed to snap from a geometrically stable low-temperature configuration to a geometrically stable high-temperature configuration when the response temperature is exceeded, and wherein the bimetal snap disk (18) is in its high-temperature configuration a support surface (68) arranged on the first housing side (24) of the switching mechanism housing (16), which is formed on the first base body (36), and thereby keeps the movable contact part (22) at a distance from the stationary contact (32). Temperature-dependent switch according to one of the preceding claims, wherein the switching mechanism unit (14) further has a spring snap disk (20) coupled to the movable contact part (22), which is in the low-temperature position of the switch (100) on one on the second housing side (26 ) is supported on the inner surface (64) arranged inside the rear derailleur housing (16). Temperature-dependent switch according to one of the preceding claims, wherein a circumferential space between the switching mechanism housing (16) and the switch housing (12) is filled with insulating compound (44).

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