TEMPERATURE-CONTROLLING SWITCH

Description

[0001] The present invention relates to a temperature-dependent switch.

[0002] Temperature-dependent switches are already known in many different forms. An example of a temperature-dependent switch is disclosed in DE 10 2011 119 632 B3.

[0003] Such temperature-dependent switches are used in a conventional manner 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 located inside the switch.

[0004] The switch is typically connected electrically in series via connecting cables into the supply circuit of the device to be protected, so that below the response temperature of the switch, the supply current of the device to be protected flows through the switch.

[0005] The switch known from DE 10 2011 119 632 B3 has a switch housing, inside which a switching mechanism is hermetically sealed. The switch housing is constructed in two parts. It has a lower part that is firmly connected to a cover part with an insulating film interposed. The switching mechanism is clamped between the cover part and the lower part. During the switch's manufacture, the switching mechanism is first loosely inserted into the lower part. The insulating film is then slipped over the lower part, and the cover part is placed on top and firmly connected to the lower part.

[0006] The temperature-dependent switching mechanism located in the switch housing comprises a spring-loaded snap-action disc, to which a movable contact part is attached, and a bimetallic snap-action disc fitted over the movable contact part. The spring-loaded snap-action disc presses the movable contact part against a stationary counter-contact located on the inside of the switch housing on the cover part. The outer edge of the spring-loaded snap-action disc rests on the lower part of the switch housing, allowing the electrical current to flow from the lower part through the spring-loaded snap-action disc and the movable contact part into the stationary counter-contact and from there into the cover part.

[0007] The temperature-dependent bimetallic snap-action disc is primarily responsible for the switch's temperature-dependent switching behavior. This is usually a multi-layer, active, sheet-metal component made of two, three, or four interconnected components with different thermal expansion coefficients. The individual layers of metals or metal alloys in such bimetallic snap-action discs are usually bonded or positively connected, for example, by rolling.

[0008] Such a bimetallic snap-action disc exhibits a first stable geometric configuration (low-temperature configuration) at low temperatures, below the response temperature of the bimetallic snap-action disc, and a second stable geometric configuration (high-temperature configuration) at high temperatures, above the response temperature of the bimetallic snap-action disc. Depending on the temperature, the bimetallic snap-action disc switches from its low-temperature configuration to its high-temperature configuration in a hysteresis manner. This process is often referred to as "snap-action," which is why it is called a "snap-action disc."

[0009] If the temperature of the bimetallic snap-action disc rises above its operating temperature due to a temperature increase in the device to be protected, it switches from its low-temperature configuration to its high-temperature configuration. As a result, the movable contact part is lifted away from the stationary counter-contact, opening the switch and shutting down the device to be protected, preventing it from heating up further.

[0010] If no return lock is provided, the bimetallic snap-action disc snaps back into its low-temperature configuration so that the switch is closed again as soon as the temperature of the bimetallic snap-action disc drops below the so-called return temperature of the bimetallic snap-action disc as a result of the cooling of the device to be protected.

[0011] In many temperature-dependent switches, the bimetallic snap-action disc is preferably inserted into the switch housing as a loose individual part during manufacture. The bimetallic snap-action disc, for example, is placed over the contact part attached to the spring-loaded snap-action disc using a central through-hole provided therein. Only when the switch housing is closed is the bimetallic snap-action disc then fixed in place and its position relative to the other components of the switching mechanism determined. However, the production of such a switch, in which the bimetallic snap-action disc is inserted individually, has proven to be relatively complicated, since several steps are necessary to insert the switching mechanism into the switch housing.

[0012] In the switch known from DE 10 2011 119 632 B3, the bimetallic snap-action disc is pre-connected (outside the switch housing) to the contact piece attached to the spring-loaded snap-action disc. To do this, the bimetallic snap-action disc is slipped over the contact piece, and then an upper collar of the contact piece is folded over. As a result, not only is the spring-loaded snap-action disc attached to the contact piece, but the bimetallic snap-action disc is also held captive to it.

[0013] The switch mechanism, consisting of the bimetallic snap-action disc, the spring-loaded snap-action disc, and the contact part, can thus be manufactured in advance as a semi-finished product, forming a captive unit that can be stored separately in bulk. During switch production, the switch mechanism can then be inserted into the switch housing as a captive unit. This simplifies switch production considerably.

[0014] In the switch known from DE 10 2011 119 632 B3, the spring-loaded snap-action disc is welded or soldered to the contact part to ensure the best possible electrical contact between these two components. However, it has been shown that, particularly during bulk storage of the pre-manufactured switchgear as a semi-finished product, the welded or soldered connection between the contact part and the spring-loaded snap-action disc can break. Such defective switches can then, of course, no longer be used. The problem, however, is that defects in the switchgear are often only detected after the entire switch has been assembled, since a functional test of the switchgear is only possible once the switch is fully assembled.

[0015] DE 10 2013 017232 A1 discloses a temperature-dependent switch according to the preamble of claim 1.

[0016] It is therefore an object of the present invention to provide a temperature-dependent switch whose switching mechanism can be pre-produced as a semi-finished product without being susceptible to damage, and which allows a functional test of the switching mechanism before its final installation in the switch. Furthermore, the switch should be relatively easy to install, have a low overall height, and be designed to be relatively pressure-resistant.

[0017] This object is achieved according to the invention by a temperature-dependent switch which comprises the following components: A temperature-dependent switching mechanism comprising a switching mechanism unit having a movable contact part coupled to a bimetallic snap-action disk, and comprising a switching mechanism housing in which the switching mechanism unit is arranged and held captively therein; and a switch housing in which the switching mechanism housing is arranged and held captively therein, wherein the switch housing has a stationary contact part that functions as a counter-contact to the movable contact part; wherein the switching mechanism housing surrounds the switching mechanism unit from 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 the second housing side and has an opening on the first housing side through which the movable contact part preferably interacts directly with the stationary contact part, wherein the switching mechanism housing has an electrically conductive base body which forms at least part of the second housing side, wherein this part of the second housing side forms a freely accessible outer side of the switch, and wherein the switch further has an insulator which electrically insulates the base body of the switching mechanism housing from the switch housing and is arranged in the interior of the switch housing.

[0018] The switch according to the invention thus comprises a switching mechanism having an additional switching mechanism housing in which the switching mechanism unit, which has the bimetallic snap-action disc and the movable contact part, is held captively. The switching mechanism housing surrounds the switching mechanism unit from a first housing side, a second housing side opposite the first housing side, and a peripheral housing side extending between and transversely between the first and second housing sides. The switching mechanism housing thus surrounds the switching mechanism unit at least partially from all six spatial directions, so that the switching mechanism cannot fall out of the switching mechanism housing.

[0019] The switchgear, including the switchgear unit and the switchgear housing surrounding the switchgear unit, can thus be pre-produced as a semi-finished product before being installed in the switch. The switchgear pre-produced as a semi-finished product can be stored in bulk. During this bulk storage, the fragile components of the switchgear unit, in particular the bimetallic snap disc and the movable contact part, are protected by the switchgear housing. Damage to these fragile components during bulk storage is largely eliminated because the fragile components of the switchgear unit are securely encapsulated in the switchgear housing.

[0020] However, the switchgear housing not only offers the advantage of securely storing the switchgear unit housed therein, it also enables a significantly simpler method of manufacturing the temperature-dependent switch. Unlike a conventional switch housing, the additional switchgear housing is not a closed housing in which the switchgear is hermetically sealed, but rather a partially open housing with an opening on the first housing side through which the movable contact part is accessible from outside the switchgear housing. The switchgear can thus be inserted together with the switchgear housing as a unit into a simplified switch housing, which forms the final switch housing.A stationary contact part is arranged on this switch housing, which acts as a counter contact to the movable contact part and interacts with the movable contact part of the switch mechanism through the opening in the switch mechanism housing. Preferably, the movable contact part interacts directly with the stationary contact part through the opening. In the low-temperature position of the switch, the movable contact part touches the stationary contact part through the opening.

[0021] During the production of the temperature-dependent switch, the switching mechanism according to the invention, including its switching mechanism housing, can initially be pre-produced as a semi-finished product and then inserted into the switch housing as a whole. This significantly simplifies not only the storage of the switching mechanism but also the production of the temperature-dependent switch.

[0022] The second housing side and the peripheral side of the derailleur housing are preferably each closed housing sides, while the first housing side is only a partially closed or a partially open housing side due to the aforementioned opening.

[0023] However, since the first side of the derailleur housing is also at least partially closed and at least partially surrounds the derailleur unit from this side as well, the derailleur unit is securely encapsulated within the derailleur housing. This makes it possible to conduct a functional test of the derailleur using the pre-produced semi-finished product before it is installed in the switch housing.

[0024] The derailleur housing has an electrically conductive base body that forms at least part of the second housing side. Preferably, the base body forms the entire second housing side and at least part of the peripheral side of the housing.

[0025] When the switch is fully assembled, the electrically conductive base body formed on the second side of the switch housing forms a freely accessible exterior of the switch. This part of the switch housing is therefore not enclosed by the switch housing when the switch is fully assembled. This part of the switch housing can therefore serve as the switch's direct electrical connection surface. The second electrical connection is preferably a part of the exterior of the switch housing, which is electrically insulated from the switch housing by an insulator.

[0026] Thus, the derailleur housing is preferably only partially, but not completely, located within the switch housing. At least the second side of the derailleur housing is freely accessible from the outside.

[0027] This type of arrangement, in which the derailleur housing is only partially but not completely enclosed by the derailleur housing, results in a very compact design for the switch. Furthermore, the switch is extremely pressure-resistant thanks to the additional derailleur housing.

[0028] The above-mentioned task is thus completely solved.

[0029] According to one embodiment, the insulator has an annular body.

[0030] This ring body can be circular in shape when viewed from above. However, the ring body can also, in principle, have a polygonal outer contour when viewed from above.

[0031] The term "ring body" should therefore be understood in a general sense. It refers to any body with a circumferentially closed contour. For example, the outer contour viewed from above can be elliptical or have any desired free form. The ring body does not necessarily have to be hollow cylindrical or toroidal, although this is preferred.

[0032] The advantage of designing the insulator as a ring body is that it electrically insulates the switchgear housing from the switch housing along its entire circumference. Furthermore, such a ring body can be arranged in the switch housing in a space-saving manner. Furthermore, the ring body is 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 switch assembly.

[0033] According to a further embodiment, the insulator is attached to the base body of the derailleur housing.

[0034] In this embodiment, the insulator forms a component belonging to the switchgear. The insulator can therefore be connected to the base body of the switchgear housing before the switch is assembled and stored together with it as a semi-finished product. During switch assembly, the switchgear can then be inserted into the switch housing together with the insulator as a single unit. This significantly simplifies switch assembly, particularly because the alignment and positioning of the switchgear housing relative to the insulator no longer need to be performed during switch assembly. Both components are already fixed to each other in advance.

[0035] Furthermore, the attachment of the insulator to the base body of the switch housing contributes to the compact and pressure-resistant design of the switch.

[0036] According to a further embodiment, at least one retaining element is formed on the base body of the derailleur housing, by means of which the insulator is attached to the base body. Preferably, several such retaining elements are formed on the base body of the derailleur housing. Particularly preferably, the at least one retaining element is formed integrally with the base body.

[0037] The insulator can thus be very easily connected to the derailleur housing. Preferably, the at least one retaining element is one or more retaining claws, which can be created by bending or crimping a free section of the base body.

[0038] According to a further embodiment, the base body of the derailleur housing is designed in one piece.

[0039] This one-piece design of the derailleur housing further contributes to the compact and pressure-resistant design of the switch. It also significantly simplifies switch assembly and reduces the number of components.

[0040] According to a further embodiment, an outer peripheral surface of the insulator rests against an inner peripheral surface of the switch housing. Preferably, the shape of the outer peripheral surface of the insulator is adapted to the shape of the inner peripheral surface of the switchgear housing.

[0041] This design is particularly advantageous when the insulator is attached to the base body of the derailleur housing. Inserting the derailleur housing and the insulator attached to it then directly leads to the correct positioning and alignment of the derailleur relative to the stationary mating contact arranged on the switch housing. Thus, the movable contact part of the derailleur is correctly positioned relative to the stationary contact part without any further measures.

[0042] According to a further embodiment, the insulator forms at least a part of the housing circumferential side of the derailleur housing and / or a part of the first housing side of the derailleur housing.

[0043] The insulator insulates the derailleur housing from the switch housing along the first housing side and / or the housing circumferential side of the derailleur housing.

[0044] According to a further embodiment, an inner circumferential surface of the insulator limits the opening in the radial direction.

[0045] The opening on the first side of the derailleur housing is then formed by the insulator. The derailleur unit located inside the derailleur housing is thus well protected. The insulator located on the derailleur housing prevents the derailleur unit from falling out of the derailleur housing, which is particularly advantageous during bulk storage of the derailleur, which is pre-produced as a semi-finished product. This design also has the advantage that the bimetallic snap-action disc can be supported on the insulator in its high-temperature configuration.

[0046] A diameter of the opening is preferably smaller than a diameter of the bimetallic snap-action disc measured parallel thereto.

[0047] The bimetal snap disc is thus securely held in the derailleur housing and cannot come loose even in the event of a shock.

[0048] According to a further embodiment, the switching mechanism is designed to hold the switch in a low-temperature position below a response temperature of the bimetallic snap-action disc, in which position the switching mechanism establishes an electrical connection between the base body of the switching mechanism housing and the stationary contact part arranged on the switch housing via the movable contact part, and to bring the switch into a high-temperature position when the response temperature is exceeded, in which the switching mechanism interrupts the electrical connection.

[0049] The electrical connection is interrupted in the high-temperature configuration of the switch by the bimetallic snap-action disc snapping from its low-temperature configuration to its high-temperature configuration when its response temperature is exceeded, thereby lifting the movable contact part from the stationary contact.

[0050] According to a preferred embodiment of the present invention, the bimetallic snap-action disc, in its high-temperature configuration, rests on a support surface arranged on the first side of the switchgear housing, which support surface is formed on the base body or on the insulator. The bimetallic snap-action disc maintains a distance between the movable contact part and the stationary contact.

[0051] Since, as already mentioned, the switching unit according to the present invention is encapsulated in the switching housing, and the bimetallic snap-action disc in its high-temperature configuration rests against the aforementioned support surface inside the switching housing, a functional test of the switching device can also be performed on the semi-finished switching device, i.e., even before the switching device is installed in the switch housing and the switch is fully assembled. The bimetallic snap-action disc can already assume its two temperature-dependent configurations inside the switching housing.

[0052] This is not possible with conventional switches because the bimetallic snap disc, due to the lack of the switchgear housing now provided specifically, rests on the switch housing in its high-temperature configuration, meaning that a functional test is only possible when the switch is fully assembled.

[0053] According to a further embodiment, the switching mechanism unit further comprises a spring-loaded snap-action disk coupled to the movable contact part, which, in the low-temperature position of the switch, rests against 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 base body of the switching mechanism housing.

[0054] The additional provision of such a spring-loaded snap-action disc has the particular advantage of relieving the load on the bimetallic snap-action disc. In the low-temperature configuration of the switch, i.e., when the circuit is closed via the switch, the spring-loaded snap-action disc serves as a current-carrying component according to this design. The bimetallic snap-action disc, in contrast, is then not a current-carrying component.

[0055] In addition, the spring-loaded snap-action disc generates the closing pressure in the switch's low-temperature position, which presses the moving contact against the stationary contact. The bimetallic snap-action disc, on the other hand, can be mounted with virtually no force in the switch's low-temperature position. This has a positive effect on the service life of the bimetallic snap-action disc and ensures that the switching point, i.e., the response temperature of the bimetallic snap-action disc, remains unchanged even after many switching cycles.

[0056] According to a further embodiment, the part of the second housing side of the switchgear housing, which forms a freely accessible outer side of the switch, has an outwardly curved, dome-shaped or pot-shaped section.

[0057] This dome- or cup-shaped section of the switch housing preferably protrudes at least partially from the switch housing. "Curved outward" here means that the dome- or cup-shaped section, as seen from the switch housing, is curved outward, i.e., outward from the interior of the switch housing. The outer side of the switch is convexly curved at this point.

[0058] This design of the switch housing makes the switch extremely pressure-resistant. Furthermore, the dome- or cup-shaped section can easily be used as the switch's external connection surface.

[0059] According to one embodiment, the outwardly curved, dome- or pot-shaped section has a first contact surface which lies in a plane with a second contact surface arranged on the switch housing.

[0060] Preferably, the second contact surface at least partially surrounds the first contact surface. Particularly preferably, the second contact surface completely surrounds the first contact surface.

[0061] If the dome- or pot-shaped section forming a first contact surface is arranged in the same plane as a second contact surface arranged on the switch housing, the temperature-dependent switch is also suitable for SMD (Surface Mounted Device) mounting. The switch can then be very easily attached to a flat circuit board because the electrical contact surfaces are in a common plane.

[0062] According to a further embodiment, a circumferential gap between the derailleur housing and the switch housing is filled with insulating compound. The insulating compound is preferably a lacquer with which the gap between the derailleur housing and the switch housing is filled.

[0063] This seals the interior of the switch, where the derailleur is located, extremely well. Furthermore, the insulating and sealing compound ensures a mechanically stable attachment of the derailleur housing to the switch housing.

[0064] It is understood that the features mentioned above and those to be explained below can be used not only in the combination specified in each case, but also in other combinations or on their own, without departing from the scope of the present invention.

[0065] Embodiments of the invention are illustrated in the drawings and explained in more detail in the following description. They show: Fig. 1 is a schematic sectional view of the temperature-dependent switch according to a first embodiment of the present invention, wherein the switch is shown in its low-temperature position; Fig. 2 is a schematic sectional view of the Fig. 1 shown switch, wherein the switch is shown in its high-temperature position; Fig. 3 is a schematic sectional view of the temperature-dependent switch according to a second embodiment of the present invention, wherein the switch is shown in its low-temperature position; Figs. 4A-4C are schematic sectional views showing individual processing steps during the manufacture of the temperature-dependent switch according to the Fig. 1 illustrated embodiment; and Fig. 5 is a schematic plan view from below of the switching mechanism used in the temperature-dependent switch according to the embodiment shown in Fig. 1 shown first embodiment.

[0066] Fig. 1-2 show a first embodiment of the switch according to the invention, each in a schematic sectional view. The switch is identified in its entirety by the reference numeral 100.

[0067] The switch 100 has a temperature-dependent switching mechanism 10 which is arranged in an electrically conductive switch housing 12.

[0068] The derailleur 10 has a functional derailleur unit 14 and a derailleur housing 16 surrounding this derailleur unit 14. The derailleur housing 16 at least partially surrounds the derailleur unit 14 from all six spatial directions. However, as explained in detail below, the derailleur housing 16 is designed as a partially open housing, so that the derailleur unit 14 is accessible from at least one spatial direction, preferably from only one spatial direction, from outside the derailleur housing 16.

[0069] Due to the fact that the derailleur housing 16 at least partially surrounds the derailleur unit 14 from all six spatial directions, the derailleur unit 14 is held captively in the derailleur housing 16. The derailleur unit 14 cannot therefore detach from the derailleur housing 16.

[0070] As long as the derailleur 10 is not installed in the switch 100 or its switch housing 12, there is preferably a certain amount of play between the derailleur unit 14 and the derailleur housing 16. In the Fig. 1 However, in the installed state of the switch 100 shown, the switching unit 14 is firmly clamped. Fig. 1 In the low-temperature position of the switch 100 shown, the switching unit 14 is clamped between the switch housing 12 and the switching housing 16.

[0071] The switching unit 14 is constructed in three parts according to the present embodiment. The switching unit 14 has a temperature-dependent bimetallic snap-action disc 18, a temperature-independent spring-action disc 20, and a movable contact part 22. The bimetallic snap-action disc 18 and the spring-action disc 20 are held captively on the contact part 22. The switching unit 14 can thus be pre-produced as a semi-finished product and then inserted as a whole into the switching housing 16 (see Fig. 4A ).

[0072] The switching mechanism 10 together with the switching mechanism unit 14 and the switching mechanism housing 16 also form a semi-finished product for the temperature-dependent switch 100 that is later produced from it. Since both the three components 18, 20, 22 of the switching mechanism unit 14 are captively connected to one another and the switching mechanism unit 14 is captively held in the switching mechanism housing 16, the switching mechanism 10 can be kept in stock as bulk material until it is installed in the temperature-dependent switch 100.

[0073] The derailleur housing 16 surrounds the 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 extending between and transversely to the first and second housing sides 24, 26.

[0074] Preferably, the derailleur housing 16 completely surrounds the 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 thus preferably form closed housing sides of the derailleur housing 16. Only the first housing side 24 is a partially open housing side of the derailleur housing 16.

[0075] In other words, the housing peripheral side 28 surrounds the derailleur unit 14 along its entire circumference, i.e., from a total of four spatial directions oriented orthogonally to one another. Furthermore, the derailleur housing 16 completely surrounds the derailleur unit 14 from a further spatial direction, namely, from a spatial direction oriented orthogonally to the second housing side 26. Only from the sixth spatial direction, which is oriented orthogonally to the first housing side 24, does the derailleur housing 16 only partially surround the derailleur unit 14.

[0076] On the first housing side 24, the switch housing 14 has an opening 30 through which the movable contact part 22 is accessible from outside the switch housing 16. Through this opening 30 in the switch housing 16, the movable contact part 22 of the switch 10 interacts with a stationary contact part 32 arranged on an inner side 34 of the switch housing 12.

[0077] A diameter D 1 of the opening 30 is smaller than a diameter D 2 of the bimetallic snap-action disc 18 and / or the spring snap-action disc 20, measured parallel thereto. Thus, although the movable contact part 22 is accessible from outside the derailleur housing 16 through the opening 30, the bimetallic snap-action disc 18 and the spring snap-action disc 20 cannot detach from or emerge from the derailleur housing 16.

[0078] The derailleur housing 16 has a base body 36 made of an electrically conductive material, for example, metal. In the presently shown embodiment, this electrically conductive base body 36 forms the second housing side 26 and the peripheral side 28 of the derailleur housing 16.

[0079] An upper part of the base body 36, which forms the second housing side 26, simultaneously forms a freely accessible outer side of the switch 100. The first housing side 24 and the housing peripheral side 28 are arranged entirely within the switch housing 12 and are therefore not accessible from outside the switch 100.

[0080] The first housing side 24 of the derailleur housing 16 is formed according to the Fig. 1 und 2 In the embodiment shown, the insulator 38 is formed by an insulator 38. This can be, for example, a plastic insulator. The insulator 38 is attached to the base body 36 of the derailleur housing 16 on the underside of the derailleur housing 16. For this purpose, several retaining claws 40 are provided, which are Fig. 1 und 2 are shown in dashed lines.

[0081] The base body 36 of the derailleur housing 16 is preferably designed as a single piece. The retaining claws 40 are preferably integrally connected to the base body 36.

[0082] According to the Fig. 1 und 2 In the embodiment shown, the derailleur housing 16 is constructed in two parts, with the base body 36 and the insulator 38 attached to it. Of course, other types of retaining elements can also be used instead of retaining claws 40 to connect the insulator 38 to the base body 36. Likewise, the base body 36 can also be glued to the insulator 38.

[0083] The insulator 38 is designed as a ring body. Its shape is preferably adapted to the shape of the switchgear housing 12. The insulator 38 rests on the inner side 34 of the base of the switch housing 12 with an insulating film 42 interposed therebetween. Although the insulating film 42 improves the electrical insulation as well as the tightness of the switch 100, this is not absolutely necessary.

[0084] With its outer peripheral surface 44, the insulator 38 rests against an inner peripheral surface 46 of the switch housing 12 (either directly or with the insulating film 42 interposed). An inner peripheral surface 48 of the insulator 38 radially delimits the opening 30 provided on the first housing side 24 of the switchgear housing 16.

[0085] During the manufacture of the switch 100, the switch housing 16 is inserted into the switch housing 12 together with the insulator 38. The switch housing 12 is preferably formed as a single piece from an electrically conductive material, preferably metal. The switch housing 12 is pot-shaped. It has a base 50 and a side wall 52 extending transversely thereto in the circumferential direction. The upper edge 54 of the side wall 52 is bent inward toward the central axis of the switch housing after the switch housing has been inserted in order to fix the switch housing 16 in the switch housing 12.

[0086] The gap 56 between the derailleur housing 16 and the switch housing 12 is filled with insulating compound 58. The insulating compound 58 provides a mechanical seal that prevents external liquids or contaminants from entering the interior of the switch 100. This creates a sealed switch housing 12 in which the derailleur housing 16 is held captively.

[0087] Since the derailleur housing 12 and the base body 36 of the derailleur housing 16 are each made of electrically conductive material, thermal contact with an electrical device to be protected can be established via their outer surfaces.

[0088] The outer surfaces also serve simultaneously for the electrical connection of the switch 100. For example, the outer side 60 of the base 50 of the switch housing 12 can function as the first electrical connection and the outer side 62 of the part of the base body 36 of the switch housing 16 that is freely accessible from the outside on the second housing side 26 can function as the second electrical connection.

[0089] When the switch 100 is assembled, the derailleur 10 is clamped between the base body 36 of the derailleur housing 16 and the switch housing 12. The insulator 38 provides electrical insulation between the base body 36 of the derailleur housing 16 and the switch housing 12.

[0090] In this way, it is ensured that an electrical contact established via the switch 100 between the switch housing 12 and the switchgear housing 16 can only be established via the switchgear 10. This electrical contact established via the switch 100 between the switch housing 12 and the switchgear housing 16 is established by the switchgear 10 only in the low-temperature position of the switch 100 (see Fig. 1 und 2 ).

[0091] In the Fig. 1 In the low-temperature position of the switch 100 shown, the temperature-independent spring snap-action disc 20 is in its first configuration and the temperature-dependent bimetallic snap-action disc 18 is in its low-temperature configuration. The spring snap-action disc 20 presses the movable contact part 22 against the stationary contact part 32, which functions as the counter contact. The switch 100 is thus in its closed position, in which an electrically conductive connection is established between the outer side 62 of the switchgear housing 16, which functions as the first switch terminal, and the outer side 60 of the switch housing 12, which functions as the second switch terminal, via the spring snap-action disc 20, the movable contact part 22, and the stationary contact part 32.

[0092] The contact pressure between the movable contact part 22 and the stationary contact part 32 is generated by the spring snap-action disc 20. In this state, the bimetallic snap-action disc 18, however, is mounted in the switchgear housing 16 with virtually no force.

[0093] If the temperature of the device to be protected and thus the temperature of the switch 100 and the bimetal snap-action disc 18 arranged therein increases to the switching temperature of the bimetal snap-action disc 18 or above the switching temperature, the bimetal snap-action disc 18 snaps from its Fig. 1 shown concave low-temperature position into its Fig. 2 shown convex high-temperature position. During this snapping action, the bimetallic snap-action disc 18 rests with its outer edge 64 on a support surface arranged on the top side of the insulator 38. As a result, the spring snap-action disc 20 simultaneously bends upwards at its center, so that the spring snap-action disc 20 is released from its Fig. 1 shown, first stable geometric configuration into its Fig. 2 shown, second geometrically stable configuration snaps over.

[0094] Fig. 2 shows the high-temperature position of switch 100, in which it is open. The circuit is thus interrupted.

[0095] When the device to be protected and thus the switch 100 including the bimetallic snap-action disk 18 cool down again, the bimetallic snap-action disk 18 snaps back into its low-temperature position when the switch-back temperature, which is also referred to as the return temperature, is reached, as is the case, for example, in Fig. 1 This allows for reversible switching behavior.

[0096] Of course, it is also possible for a corresponding locking device to prevent the switch 100 from switching back to the high-temperature position once it has snapped over. Such locking devices, which are used particularly in one-shot switches where switching back to the high-temperature position is to be prevented, are already known in numerous prior art designs.

[0097] It is also possible to equip the switching mechanism unit 14 without the spring-loaded snap-action disk 20. In such a case, the switching mechanism unit 14 then "only" has the bimetallic snap-action disk 18 and the movable contact part 22. The bimetallic snap-action disk 18 then not only ensures the switching behavior but also simultaneously generates the contact pressure between the movable contact part 22 and the stationary contact part 32 in the low-temperature position of the switch 100. The bimetallic snap-action disk 18 is then used as the current-carrying component of the switching mechanism 10.

[0098] Fig. 3 shows a schematic sectional view of a second embodiment of the switch 100. In this regard, the differences to the switch 100 according to the Fig. 1 und 2 The first embodiment shown in Figure 1 is explained below. Since the general functionality of the Fig. 3 The switch 100 shown in the figure does not differ from the one shown in Fig. 1 und 2 shown switch 100, this will not be explicitly discussed again here.

[0099] A difference in Fig. 3 The advantage of the switch 100 shown in the second embodiment of the present invention lies in its even flatter design. In particular, the switch housing 16 is designed even flatter here. While the part of the second housing side 26 of the switch housing 16, which forms a freely accessible outer side of the switch 10, in Fig. 1 has a dome-shaped section 66, this part 68 of the derailleur housing 16 is in accordance with the Fig. 3 In the embodiment shown, the switch 100 is pot-shaped. This pot-shaped section 68 has a flat contact surface 70 on its upper side, which is arranged in a plane E with a second contact surface 72 arranged on the switch housing 12. These two contact surfaces 70, 72 are suitable for SMD mounting of the switch 100. The switch 100 can thus be very easily mounted, so to speak, overhead on a flat circuit board.

[0100] The second contact surface 72, which is arranged on the surface of the switch housing 12, preferably completely surrounds the first contact surface 70 along the entire circumference of the switch 100. The first contact surface 70 is preferably circular. The second contact surface 72 is preferably annular.

[0101] The switch housing 16 is also designed inside the switch according to the Fig. 3 shown second embodiment is designed flatter. The base body 36 of the switching mechanism housing 16 is again made in one piece from an electrically conductive material, for example metal. In this embodiment, too, the switching mechanism unit 14 is encapsulated in the switching mechanism housing 16. The switching mechanism housing 16 surrounds the switching mechanism unit 14 at least partially from all six spatial directions. The first housing side 24 of the switching mechanism housing 16 is again designed as a partially open housing side, which has a central opening 30, through which the movable contact part 22 interacts directly with the stationary contact part 32. In the Fig. 1 and 3 In the low temperature position of the switch 100 shown, the movable contact part 22 touches the stationary contact part 32 through the opening 30.

[0102] The opening 30 is radially delimited by the base body 36 of the derailleur housing 16. On the first housing side 24, the base body 36 of the derailleur housing 16 has an inwardly folded, circumferential edge 74. Instead of such an edge 74, however, individual webs can also be provided that protrude radially inward from the housing peripheral side 28.

[0103] The edge 74 or the mentioned webs serve according to the Fig. 3 shown embodiment as a counterholder for the bimetallic snap-action disc 18. The edge 74 has a support surface 63 on which the bimetallic snap-action disc 18 can be supported in its high-temperature position.

[0104] Unlike the one in Fig. 1 und 2 In the first embodiment shown, the bimetallic snap-action disk 18 in its high-temperature position is no longer supported on the insulator 38, but on the base body 36 of the switchgear housing 16 itself, namely on the edge 74 or the aforementioned webs.

[0105] Another difference lies in the slightly different design of the insulator 38. Here, the insulator 38 is also designed as an annular body, the outer peripheral surface of which rests against the inner peripheral surface of the switch housing 12. However, the insulator 38 has an approximately L-shaped cross-section. The base body of the switchgear housing 16 rests on an inner peripheral shoulder 76 of the insulator 38.

[0106] According to this embodiment, it is also preferred that the insulator 38, as part of the switch housing 16, be inserted into the switch housing 12 as a single unit during the manufacture of the switch 100. Therefore, the insulator 38 is preferably connected to the base body 36 of the switch housing 16. This connection can be made using one or more retaining elements, for example, at least one retaining claw. Alternatively, the insulator 38 can be glued, welded, or soldered to the base body 36 of the switch housing 16.

[0107] Fig. 4A-C illustrate in a schematic manner several sequentially running work steps in the assembly of the switch 100 according to the first embodiment.

[0108] In a first assembly step, the switching unit 14, which has the bimetallic snap-action disc 19, the spring-loaded snap-action disc 20, and the movable contact part 20, is inserted into the base body 36 of the switching housing 16 from below. The preformed base body 36 can, for example, be designed as a deep-drawn component. Fig. 4A The first housing side 25 is still completely open, allowing the switching unit 14 to be easily inserted from below. Part of the peripheral housing side 28, as well as the second housing side 26, are designed as closed housing sides. Several preformed retaining claws 40 protrude vertically downward from the peripheral housing side 28, approximately starting at the dashed line 78.

[0109] In a second assembly step, the insulator 38 is then pushed onto the retaining claws 40. For this purpose, the insulator 38 preferably has a plurality of through-holes 8 distributed around the circumference, through which the retaining claws are inserted. The retaining claws 40 are then folded inward, as indicated by the arrows 82, to fix the insulator 38 to the base body 36 of the derailleur housing 16. The derailleur 10 is thus completed.

[0110] The finished switchgear 10, which can be stored as a semi-finished product in bulk storage, is in the upper part of Fig. 4C shown. Fig. 5 shows a plan view from below of the rear derailleur 10, whereby in particular the previously mentioned type of fastening of the insulator 38 to the base body 36 of the rear derailleur housing 16 is again visible.

[0111] In the last assembly step, which is Fig. 4CAs shown, the switching mechanism 10, which is pre-produced as a semi-finished product, is inserted into the switch housing 12 and the switch housing 12 is closed by folding over the upper edge 54 (see arrows 84).

[0112] As a final process step, not shown here, the insulating and sealing compound 58 is introduced into the space 56 between the switchgear housing 16 and the switch housing 12.

Claims

1. A temperature-dependent switch (100), comprising: - a temperature-dependent switching mechanism (10) having a switching mechanism unit (14), which comprises a movable contact part (22) coupled to a bimetallic snap-action disc (18), and having a switching mechanism housing (16), in which the switching mechanism unit (14) is arranged and held captively therein; and - a switch housing (12), in which the switching mechanism housing (16) is arranged and held captively therein, wherein the switch housing (12) comprises a stationary contact part (32), which acts as a mating contact to the movable contact part (22); wherein the switching mechanism housing (16) surrounds the switching mechanism unit (14) from a first housing side (24), a second housing side (26) opposite the first housing side (24), and a housing circumferential side (28) extending between and transversely to the first and the second housing sides (24, 26), and on the first housing side (24) comprises an opening (30) through which the movable contact part (22) interacts with the stationary contact part (32), wherein the switching mechanism housing (16) comprises an electrically conductive base body (36), which forms at least part of the second housing side (26), characterized in that said part of the second housing side (26) forms a freely accessible outside (62) of the switch (100), and that the switch (100) further comprises an insulator (38), which electrically insulates the base body (36) of the switching mechanism housing (16) from the switch housing (12) and is arranged inside the switch housing (12).

2. The temperature-dependent switch according to claim 1, wherein the insulator (38) comprises an annular body.

3. The temperature-dependent switch according to claim 1 or 2, wherein the insulator (38) is fastened to the base body (36) of the switching mechanism housing (16).

4. The temperature-dependent switch according to claim 3, wherein at least one holding element (40), by means of which the insulator (38) is fastened to the base body (36), is formed on the base body (36) of the switching mechanism housing (16).

5. The temperature-dependent switch according to any one of the preceding claims, wherein the base body (36) of the switching mechanism housing (16) is integrally formed in one piece.

6. The temperature-dependent switch according to any one of the preceding claims, wherein an outer circumferential surface (44) of the insulator (38) abuts an inner circumferential surface (46) of the switch housing (12).

7. The temperature-dependent switch according to any one of the preceding claims, wherein the insulator (38) forms at least at least a part of the housing circumferential side (28) of the switching mechanism housing (16) and / or at least a part of the first housing side (24) of the switching mechanism housing (16).

8. The temperature-dependent switch according to any one of the preceding claims, wherein an inner circumferential surface (48) of the insulator (38) radially delimits the opening (30).

9. The temperature-dependent switch according to any one of the preceding claims, wherein a diameter (D1) of the opening (30) is smaller than a diameter (D2) of the bimetallic snap-action disc (18) that is measured parallel to the diameter of the opening (30).

10. The temperature-dependent switch according to any one of the preceding claims, wherein the switching mechanism (10) is configured so as, below a response temperature of the bimetallic snap-action disc (18), to keep the switch (100) in a lowtemperature position in which the switching mechanism (10) establishes via the movable contact part (22) an electrical connection between the base body (36) of the switching mechanism housing (16) and the stationary contact part (32) arranged on the switch housing (12), and, upon exceeding the response temperature, to move the switch (100) to a high-temperature position in which the switching mechanism (10) interrupts the electrical connection.

11. The temperature-dependent switch according to claim 10, wherein the bimetallic snap-action disc (18) is configured to snap over from a geometrically stable lowtemperature configuration to a geometrically stable high-temperature configuration upon exceeding the response temperature, and wherein the bimetallic snap-action disc (18) is supported in its high-temperature configuration on a supporting surface (63), which is arranged on the first housing side (24) of the switching mechanism housing (16) and is formed on the base body (36) or on the insulator (38), and thereby keeps the movable contact part (22) at a distance from the stationary contact (32).

12. The temperature-dependent switch according to claim 10 or 11, wherein the switching mechanism unit (10) further comprises a snap-action spring disc (20) which is coupled to the movable contact part (22) and is supported in the low-temperature position of the switch (100) on an internal surface arranged on the second housing side (26) in the interior of the switching mechanism housing (16).

13. The temperature-dependent switch according to any one of the preceding claims, wherein the part of the second housing side (26) of the switching mechanism housing (16), which forms the freely accessible outside (62) of the switch (100), comprises an outwardly arched, domed or pot-shaped portion (66, 68).

14. The temperature-dependent switch according to claim 13, wherein the outwardly arched, domed or pot-shaped portion (66, 68) comprises a first contact surface (70), which lies in a plane (E) with a second contact surface (72) arranged on the switch housing (12).

15. The temperature-dependent switch according to any one of the preceding claims, wherein an intermediate space (56) extending circumferentially between the switching mechanism housing (16) and the switch housing (12) is filled with insulating compound (58).