Temperature-dependent switching device and temperature-dependent switch with such a switching device

Description

[0001] The present invention relates to a temperature-dependent switching mechanism for a temperature-dependent switch. The present invention further relates to a temperature-dependent switch with such a temperature-dependent switching mechanism.

[0002] Temperature-dependent switches are already known in a large number of forms. US 2015 / 109092 A1, which forms the basis for the preamble of claim 1, discloses a temperature-dependent switching mechanism with a bimetallic snap disc, a movable contact element, and a spring-loaded snap disc, wherein the switching mechanism has an annular frame in which the bimetallic snap disc and the spring-loaded snap disc are captive. Further exemplary temperature-dependent switches are disclosed in DE 10 2011 119 632 B3, WO 2006 / 105560 A1, and US 2,861,151 A.

[0003] Such temperature-dependent switches serve, 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 located inside the switch.

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

[0005] In the switch known from DE 10 2011 119 632 B3, the switching mechanism is arranged inside a switch housing. The switch housing has a two-part construction. It comprises a lower part that is rigidly connected to a cover part with an insulating film in between. The temperature-dependent switching mechanism arranged in the switch housing includes a spring-loaded snap disc to which a movable contact part is attached, as well as a bimetallic snap disc that fits over the movable contact part. The spring-loaded snap disc presses the movable contact part against a stationary mating contact located on the inside of the switch housing on the cover part. The outer edge of the spring-loaded snap disc is supported in the lower part of the switch housing, so that the electric current flows from the lower part through the spring-loaded snap disc and the movable contact part into the stationary mating contact and from there into the cover part.

[0006] The temperature-dependent switching behavior of the switch is primarily due to the temperature-dependent bimetallic snap disc. This is usually designed as a multi-layered, active, sheet-metal component consisting of two, three, or four interconnected components with different coefficients of thermal expansion. The connection between the individual layers of metals or metal alloys in such bimetallic snap discs is usually material-bonded or form-fitted and is achieved, for example, by rolling.

[0007] Such a bimetallic snap disc exhibits a first stable geometric configuration (low-temperature configuration) at low temperatures, below the response temperature of the bimetallic snap disc, and a second stable geometric configuration (high-temperature configuration) at high temperatures, above the response temperature of the bimetallic snap disc. The bimetallic snap disc switches from its low-temperature configuration to its high-temperature configuration depending on the temperature, following a hysteresis-like process.

[0008] If the temperature of the bimetallic snap disc rises above its activation temperature due to a temperature increase in the device being protected, the disc switches from its low-temperature configuration to its high-temperature configuration. In this process, the bimetallic snap disc works against the spring-loaded snap disc, lifting the movable contact from the stationary counterpart contact. This opens the switch, shutting down the device and preventing it from heating up further.

[0009] Unless a reset lock is provided, the bimetallic snap disc snaps back into its low-temperature configuration, so that the switch closes again as soon as the temperature of the bimetallic snap disc drops below the so-called return temperature of the bimetallic snap disc as a result of the cooling of the device to be protected.

[0010] In its low-temperature configuration, the bimetallic snap disc is preferably mounted in the switch housing without mechanical stress, and is not used to conduct the current. This has the advantage of a longer service life for the bimetallic snap disc, and the switching point, i.e., the response temperature of the bimetallic snap disc, remains unchanged even after many switching cycles.

[0011] In many temperature-dependent switches, the bimetallic snap disc is therefore preferably inserted into the switch housing as a loose component during manufacturing. The bimetallic snap disc, for example, is fitted over the contact part attached to the spring-loaded snap disc, using a central through-hole provided in it. Only when the switch housing is closed is the bimetallic snap disc then fixed in its position 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 disc is inserted separately, has proven to be relatively cumbersome, as several steps are necessary to insert the switch into the switch housing.

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

[0013] The switching mechanism, consisting of the bimetallic snap disc, the spring snap disc, and the contact element, can thus be pre-manufactured as a semi-finished product, forming a captive unit that can be stored separately in bulk. During switch manufacturing, the switching mechanism can then be inserted into the switch housing as a single, captive unit in just one step. This simplifies switch production considerably.

[0014] The spring-loaded snap disc in the switch known from DE 10 211 119 632 B3 is welded or soldered to the contact part to ensure the best possible electrical contact between the two components. However, it has been observed that, particularly during bulk storage of the prefabricated switch assembly, the welded or soldered connection between the contact part and the spring-loaded snap disc can break. Such defective switches are then, of course, no longer usable. The particular problem is that such a defect can only be detected after the switch has been assembled, as a functional test of the switch assembly is only possible at that point.

[0015] German patent DE 199 19 648 A1 also proposes a temperature-dependent switch whose switching mechanism can be pre-produced as a semi-finished product. In this switching mechanism as well, the bimetallic snap disc, the spring snap disc, and the contact element form a captive unit before installation in the switch housing. This unit can be inserted into the switch housing as a whole during production and can be stored in bulk beforehand. In this switching mechanism, the contact element has a jacket made of a softer metal and a core made of electrically conductive, harder metal. The bimetallic snap disc and the spring snap disc are attached to the jacket and molded into the softer metal of the jacket. However, it has been found that this type of connection frequently leads to the bimetallic snap disc and / or the spring snap disc unintentionally detaching from the contact element during storage of the switching mechanism.

[0016] Another method for pre-producing the switching mechanism as a semi-finished product is known from DE 29 17 482 A1 and DE 10 2007 014 237 A1. The captive unit of the switching mechanism is achieved by connecting the bimetallic snap disc and the spring snap disc to each other via a rivet. Depending on the switch design, this rivet can also form the movable contact part of the switching mechanism. The rivet has a two-part construction and comprises a rivet pin that interacts with a hollow rivet or a rivet pin with a counter-holder attached to it.

[0017] While this type of rivet connection between the spring-loaded snap washer and the bimetallic snap washer has proven to be a mechanically durable connection over the long term, it does have other disadvantages. For example, the bimetallic snap washer is usually fixed to the rivet, which can lead to deformation and thus malfunctions of the bimetallic snap washer. Therefore, storing the switchgear in bulk is still possible in principle. However, damage to the switchgear during bulk storage cannot be ruled out.

[0018] It is therefore an object of the present invention to provide a temperature-dependent switching mechanism that can be pre-produced as a semi-finished product and stored in bulk without being susceptible to damage that would lead to a defect in the switching mechanism. The pre-produced switching mechanism should then also be as easy as possible to use in a temperature-dependent switch and enable its manufacture with as few work steps as possible. Furthermore, a functional test of the switching mechanism should be possible even before its installation in the switch.

[0019] This problem is solved according to the invention by a temperature-dependent switching device according to independent claim 1 and a temperature-dependent switch according to claim 14.

[0020] According to the invention, the switching mechanism thus comprises an additional switching mechanism housing in which the switching mechanism unit, which includes the bimetallic snap disc, the spring snap disc and the contact element, is held captive but with some play. The base body of the switching mechanism housing is preferably constructed in one piece.

[0021] Similar to the prior art cited at the beginning, the bimetallic snap disc, the spring snap disc and the contact part form a captively held switching unit that can be pre-produced as a semi-finished product before being inserted into a temperature-dependent switch.

[0022] This switching unit is now additionally enclosed in a switching unit housing, so that the fragile components of the switching unit, in particular the bimetallic snap disc and the spring snap disc, are protected by the switching unit housing during bulk storage. Damage to these fragile components during bulk storage is thus largely prevented, as the fragile components of the switching unit are securely encapsulated within this switching unit housing.

[0023] However, the switchgear housing not only offers the advantage of safely storing the fragile switchgear components during bulk storage, it also enables a much simpler way of manufacturing the temperature-dependent switch in which the switchgear is later used.

[0024] Unlike a conventional switch housing, the newly provided switching mechanism housing is not a closed enclosure in which the switching mechanism is hermetically sealed, but rather a partially open housing. It features a first opening on one side and a second opening on the other, through which the contact element is accessible from outside the switching housing. The switching mechanism, along with its housing, can thus be inserted as a single unit into a simplified outer switch housing, which forms the final switch housing. A mating contact can be arranged on this outer switch housing, interacting with the externally accessible contact element of the switching mechanism. No modification or further processing of the switching mechanism housing is necessary.

[0025] In the manufacture of the temperature-dependent switch, the switching mechanism according to the invention, including its housing, can first be pre-produced as a semi-finished product and then inserted as a whole into a switch housing. This significantly simplifies not only the storage of the switch but also the manufacturing of the temperature-dependent switch.

[0026] Since all components of the switch are already functionally arranged on the switching mechanism, which is pre-produced as a semi-finished product, the switch housing surrounding the switching mechanism only needs to have two contacts that are electrically connected to each other via the switching mechanism. No further complex components need to be provided on the switch housing. It is therefore also possible to insert the switching mechanism according to the invention directly into an external switch housing that is integrally designed with the device to be monitored and is significantly simpler in construction than conventional switch housings that hermetically seal the switching mechanism. Of course, it is also possible to insert the switching mechanism, including its switching mechanism housing, into a conventional switch housing, as is known, for example, from DE 10 2011 119 632 B3.

[0027] A further advantage of the switching mechanism according to the invention is that a functional test can be carried out even before it is installed in the switch or the switch housing. Due to the now provided switch housing, in which the switching mechanism unit is encapsulated, the snap-action behavior of the bimetallic snap disc can be tested directly in the switching mechanism housing.

[0028] A switching mechanism of a very similar design is already described in an earlier German patent application with the file number DE 10 2022 118 405.6. In contrast to the switching mechanism disclosed therein, the switching mechanism according to the invention has the aforementioned second opening on the second side of the switching mechanism housing, through which the contact part is accessible from outside the switching mechanism housing. This second opening offers the advantage of increased freedom of movement of the contact part of the switching mechanism.

[0029] This allows the contact element to move more freely within the switch housing, particularly when the switch opens – i.e., when the bimetallic snap disc changes from its low-temperature to its high-temperature configuration – and, for example, "dive" into the second opening. This enables a more compact switch housing overall, as its height, in particular, can be reduced.

[0030] The above-mentioned task has therefore been completely solved.

[0031] Preferably, the outer casing side is designed as closed casing sides, and only the first casing side and the second casing side opposite it are designed as partially open casing sides (due to the first and second openings provided thereon).

[0032] According to one embodiment, the contact part permanently protrudes from the switchgear housing through the first opening or is movable together with the bimetallic snap disc and the spring snap disc within the switchgear housing in such a way that the contact part protrudes from the switchgear housing through the first opening when subjected to a corresponding movement.

[0033] This ensures easy access to the contact element from outside the switchgear housing. This significantly simplifies the electrical connection and contacting of the switchgear. The contact element is thus at least partially accessible from the outside, meaning that the switch housing of the final switch only needs to have a first contact, which is electrically connected to the switchgear housing, and a second contact, which acts as a mating contact to the contact element of the switchgear.

[0034] As already mentioned, the present invention relates not only to the temperature-dependent switching mechanism itself, but also to a temperature-dependent switch which, in addition to the temperature-dependent switching mechanism according to the invention, comprises a switch housing surrounding the switching mechanism, which has a first contact and a second contact, wherein the switching mechanism is configured to establish an electrical connection between the first and second contacts below a response temperature of the bimetallic snap disc and to interrupt the electrical connection when the response temperature is exceeded.

[0035] The switching mechanism is preferably designed to press the contact element through the first opening against the first contact below the response temperature of the bimetallic snap disc. The first opening in the switching mechanism housing thus preferably simplifies the electrical contact between the switching mechanism and the switch housing when the switch is closed.

[0036] According to one embodiment, the bimetallic snap disc is configured to snap from a low-temperature configuration to a high-temperature configuration when a response temperature is exceeded, and wherein the contact part protrudes from the switchgear housing through the first opening when the bimetallic snap disc is in its low-temperature configuration.

[0037] Below the response temperature of the bimetallic snap disc, i.e. as long as the switching mechanism is in its low-temperature position, the contact part can protrude through the first opening from the switching mechanism housing and establish direct mechanical and simultaneously electrical contact with the contact arranged on the switch housing.

[0038] If, on the other hand, the bimetallic snap disc is in its high-temperature configuration (after exceeding the response temperature), the contact part is preferably arranged in the second opening or protrudes from the switchgear housing through the second opening.

[0039] The second opening in the switch housing thus provides space for the contact element in the switch's high-temperature position. In other words, no extra space needs to be provided within the switch housing into which the contact element can "jump" when the bimetallic snap disc switches from its low-temperature to its high-temperature configuration. A certain degree of freedom of movement for the contact element within the switch housing is essential during this switching process. Since the contact element can "dive" into the second opening in the switch's high-temperature position, this freedom of movement does not need to be accommodated by enlarging the switch housing. The switch housing can therefore be designed to be comparatively compact.

[0040] According to a further embodiment of the temperature-dependent switching mechanism, the inner diameter of the first opening as well as the inner diameter of the second opening is each smaller than an outer diameter of the bimetallic snap disc measured parallel to it and / or smaller than an outer diameter of the spring snap disc measured parallel to it.

[0041] The switching mechanism assembly, comprising the bimetallic snap disc, the spring-loaded snap disc, and the contact element, is thus securely held in the switching mechanism housing in a simple yet free-moving manner. This ensures that the switching mechanism assembly cannot unintentionally detach from the switching mechanism housing, even when the switching mechanism is stored as bulk material. The switching mechanism cannot, therefore, detach from the switching mechanism housing through either the first or second opening.

[0042] The inner diameter of the first opening and the inner diameter of the second opening each refer to the clear dimension of the respective opening. If the respective opening is not circular, it refers to the smallest possible diameter at the narrowest point of the respective opening.

[0043] Preferably, the inner diameter of the second opening is smaller than the inner diameter of the first opening.

[0044] This is because the switching mechanism, in its low-temperature position, occupies more space on the first side of the switching mechanism housing than it does on the second side in its high-temperature position. Since the electrical contact is preferably made through the first opening, this opening should be large enough to prevent a short circuit, while for the second opening, it is sufficient if its inner diameter is slightly larger than the outer diameter of the contact element, so that the contact element fits into the second opening in the switching mechanism's high-temperature position.

[0045] According to a preferred embodiment, the second opening is designed as a centrally arranged hole in the second housing side of the switchgear housing.

[0046] The second opening could, for example, be a cylindrical hole in the switchgear housing. The inner diameter of this hole is preferably larger than the outer diameter of the contact part.

[0047] According to a further embodiment, the switchgear housing has a side wall forming the housing circumference, wherein at least one free, upper section of this side wall is bent over and forms the first housing side.

[0048] The switching mechanism can be manufactured very simply in this way by crimping the at least one upper section of the side wall. This crimped upper section of the side wall then at least partially surrounds the switching mechanism unit from the first housing side. However, as already mentioned, the first housing side is partially open, since the crimped upper section of the side wall does not cover the entire first housing side, but leaves a first opening through which the contact part is accessible from outside the switching mechanism housing. The first opening preferably forms a central part in the middle of the first housing side.

[0049] The upper edge of the side wall of the switchgear housing can be bent over completely, so that it radially limits the first opening all around.

[0050] According to an alternative embodiment, the at least one free, upper section of the side wall has several separate, circumferentially distributed, bent segments that form the first housing side. These individual segments can be bent or crimped much more easily to avoid wrinkling than a complete, circumferential upper edge of the side wall of the switchgear housing.

[0051] According to a further embodiment, the bimetallic snap disc is designed to snap from a geometrically stable low-temperature configuration to a geometrically stable high-temperature configuration when a response temperature is exceeded, wherein the bimetallic snap disc in its low-temperature configuration is spaced away from an inner surface of the at least one bent section arranged inside the switchgear housing and in its high-temperature configuration is supported on the inner surface of the at least one bent section.

[0052] The bent upper section of the side panel, forming the first side of the switch housing, not only serves to securely hold the switch unit within the housing, but also, according to this design, acts as a support against which the bimetallic snap disc, in its high-temperature configuration, is internally braced. This ensures that the switch assembly, along with its housing, can be used fully functionally even without a switch housing. The bimetallic snap disc, in its high-temperature configuration, can brace itself against the switch housing, allowing the contact element connected to the bimetallic snap disc to move within the housing when the disc snaps into place. Therefore, a functional test of the switch assembly can be easily performed even before it is installed in the switch.

[0053] The two configurations of the bimetallic snap disc mentioned refer to different geometric positions of the bimetallic snap disc. In the low-temperature configuration, the bimetallic snap disc is preferably convex on its upper surface. In the high-temperature configuration, the bimetallic snap disc is preferably concave on its upper surface.

[0054] According to a further embodiment, the switchgear housing is designed as a single piece. It therefore preferably consists of a single piece from which all housing sides are integrally formed. This reduces the total number of parts and thus the costs. At the same time, this contributes to a very pressure-resistant design of the switchgear. This is advantageous not only during storage of the switchgear as bulk material, but also in its final installed state, when the switchgear is mounted in the temperature-dependent switch.

[0055] According to a further embodiment, the base body of the switchgear housing comprises an electrically conductive material. Preferably, the base body of the switchgear housing consists of an electrically conductive material. Particularly preferably, this electrically conductive material is a metal.

[0056] This design allows the switchgear housing to be used as the current-carrying component of the temperature-dependent switch. In principle, it is also possible to use the switchgear housing itself as one of the two electrical contacts within the temperature-dependent switch. This simplifies the switch's construction and enables very easy electrical connection.

[0057] According to a further embodiment, the switching mechanism housing is designed to be rotationally symmetrical about a central axis. The switching mechanism contained therein is preferably also designed to be rotationally symmetrical about the central axis.

[0058] This simplifies the installation of the switching mechanism, including its housing, within the housing of the temperature-dependent switch, as the switching mechanism can be used in various positions rotated around the central axis within the temperature-dependent switch. Furthermore, the rotationally symmetrical design of the switching mechanism housing ensures an even distribution of force in all directions (radial directions).

[0059] According to a further embodiment, the bimetallic snap disc has a first through-hole and the spring-loaded snap disc has a second through-hole, wherein the contact part is guided through the first and second through-holes, and wherein the contact part further comprises a support shoulder projecting radially from the base body, a first locking element arranged on a first side of the support shoulder, and a second locking element arranged on a second side of the support shoulder opposite the first side. The bimetallic snap disc is arranged between the first locking element and the support shoulder and is held captive, but with some play, against the contact part by the first locking element and the support shoulder.The spring-loaded snap disc is positioned between the second locking element and the support shoulder and is held captive by the second locking element and the support shoulder, but with play at the contact part.

[0060] The locking elements can each consist of one or more retaining claws that project radially from the base body of the contact part. Alternatively, the locking elements can each have a crimped collar that extends circumferentially around the base body of the contact part. Both the retaining claws and this crimped collar can form individual circumferential sections of the base body or encircle the entire base body. In this way, the two snap discs are held captive, but with some play, on the base body.

[0061] The locking elements for holding and locking the bimetallic snap disc and the spring-loaded snap disc are preferably integrally connected to the base body of the contact part, and can be produced by forming a respective part of the base body. The contact part is thus formed in one piece, and the base body of the contact part is integrally connected to the support shoulder and the locking elements. Overall, the contact part, the bimetallic snap disc, and the spring-loaded snap disc thus form a switching unit consisting of only three parts, which is realized as a captive unit.

[0062] The three-part design of the derailleur unit has the advantage of requiring as few components as possible, as well as the advantage of a mechanically stable and durable derailleur design.

[0063] According to a further embodiment, the first through-hole is arranged centrally in the bimetallic snap disc. Similarly, the second through-hole is preferably arranged centrally in the spring-loaded snap disc.

[0064] The bimetallic snap disc and the spring-loaded snap disc are preferably each designed in a circular disc shape. Furthermore, the bimetallic snap disc and the spring-loaded snap disc are preferably each designed to be bistable.

[0065] In this context, "bistable" means that both snap discs have two different, stable geometric configurations / positions. The two stable configurations / positions of the bimetallic snap disc are temperature-dependent, while the two stable configurations / positions of the spring-loaded snap disc are temperature-independent. This ensures that after snapping from one configuration to the other, both snap discs remain stable in their respective positions without any unwanted snapping back. The switch mechanism only snaps when the activation temperature of the bimetallic snap disc is exceeded or the return temperature of the bimetallic snap disc is undershot. The spring-loaded snap disc always snaps into its opposite configuration / position simultaneously with the bimetallic snap disc.

[0066] It is understood that the features mentioned above and those to be explained below can be used not only in the configuration specified, but also in other combinations or on their own, without leaving the scope of the present invention.

[0067] Exemplary embodiments of the invention are shown in the drawings and are explained in more detail in the following description. They show: Fig. 1 a schematic sectional view of the temperature-dependent switching device according to an embodiment of the present invention; Fig. 2 a top view of the in Fig. 1 shown switching mechanism; Fig. 3 a schematic sectional view of the temperature-dependent switch according to an embodiment of the present invention, wherein the switch is in its low-temperature position; and Fig. 4 a schematic sectional view of the in Fig. 3 shown temperature-dependent switch, with the switch in its high-temperature position.

[0068] Fig. 1 Figure 1 shows an embodiment of the switching mechanism according to the invention in a schematic sectional view. The switching mechanism as a whole is designated by the reference numeral 10.

[0069] The switching mechanism 10 is a temperature-dependent switching mechanism. It comprises a functional switching unit 12 and a switching unit housing 14 surrounding this switching unit 12. The switching unit housing 14 has a one-piece base body that at least partially surrounds the switching unit 12 in all six spatial directions. As explained in detail below, the switching unit housing 14, or rather the base body forming the switching unit housing, is designed as a partially open housing, so that the switching unit 12 is accessible from outside the switching unit housing 14 from at least two spatial directions, preferably from only two spatial directions.

[0070] Because the switching mechanism housing 14 at least partially surrounds the switching mechanism unit 12 in all six spatial directions, the switching mechanism unit 12 is captive within the switching mechanism housing 14. As long as the switching mechanism 10 is not installed in a temperature-dependent switch, there is preferably some play between the switching mechanism unit 12 and the switching mechanism housing 14. The switching mechanism unit 12 is movable within the switching mechanism housing 14 when the switching mechanism 10 is in its low-temperature position.

[0071] The switching unit 12 is composed of three parts. The switching unit 12 comprises a temperature-dependent bimetallic snap disc 16, a temperature-independent spring snap disc 18, and a contact part 20. The bimetallic snap disc 16 and the spring snap disc 18 are captive and held in place on the contact part 20.

[0072] The switching unit 12 can thus be pre-produced as a semi-finished product and then inserted as a whole into the switching unit housing 14. The switching mechanism 10, together with the switching unit 12 and the switching unit housing 14, then also constitute a semi-finished product for a temperature-dependent switch to be produced from it later.

[0073] Since the three components 16, 18, 20 of the switching unit 12 are captive and the switching unit 12 is captive within the switching unit housing 14, the switching unit 10 can be stored in bulk until it is installed in a temperature-dependent switch. It should be noted, however, that the components 16, 18, 20 of the switching unit 12 themselves do not necessarily have to be captive, as this connection is already provided by the switching unit housing 14. The bimetallic snap disc 16 and the spring snap disc 18 can therefore also be loosely placed on the contact part 20, as long as the three components 16, 18, 20 are held together by the switching unit housing 14. Even then, the switching unit 10 can be pre-produced and stored in bulk.

[0074] The switching mechanism housing 14 protects the fragile components of the switching mechanism unit 12, in particular the bimetallic snap disc 16 and the spring-loaded snap disc 18, from damage during bulk material storage. Furthermore, housing the switching mechanism unit 12 in such a switching mechanism housing 14 has the advantage that the switching mechanism 10 can be very easily inserted into a temperature-dependent switch being manufactured. Due to this very simple handling of the switching mechanism, the assembly process of the temperature-dependent switch can be readily automated.

[0075] The single-piece base body forming the switching mechanism housing 14 surrounds the switching mechanism unit 12 at least partially from a first housing side 22, a second housing side 24 opposite the first housing side 22, and a housing circumferential side 26 extending between and transversely to the first and second housing sides 22, 24. Preferably, the switching mechanism housing 14 completely surrounds the switching mechanism unit 12 from the housing circumferential side 26. The housing circumferential side 26 thus preferably forms a closed housing side of the switching mechanism housing 14. The first housing side 22 and the second housing side 24 are each partially open housing sides of the switching mechanism housing 14. In other words, the housing circumferential side 26 surrounds the switching mechanism unit 12 along its entire circumference, i.e., from a total of four mutually orthogonal spatial directions.Furthermore, the switching mechanism housing 14 only partially surrounds the switching mechanism unit 12 from the two remaining spatial directions, which are orthogonal to the four mentioned spatial directions.

[0076] On the first housing side 22, the base body of the switchgear housing 14 has a first opening 28 through which the contact part 20 is accessible from outside the switchgear housing 14. On the second housing side 24, the base body of the switchgear housing 14 has a second opening 29 through which the contact part 20 is also accessible from outside the switchgear housing 14.

[0077] According to the in Fig. 1 In the illustrated embodiment, the contact part 20 permanently protrudes through the first opening 28 to the outside. However, depending on the design of the height of the switching mechanism housing 14, this is not necessarily the case. In principle, it is sufficient if the contact part 20 is accessible from the outside through the first opening 28 and the switching mechanism unit 12 is movable within the switching mechanism housing 14 such that the contact part 20 protrudes through the first opening 28 to the outside when it moves within the switching mechanism housing 14. This is preferably the case, in particular, when the switching mechanism 10 is in its Fig. 1 The low temperature setting shown is located.

[0078] The second opening 29, however, is particularly needed when the switching mechanism 10 is in its high-temperature position (see Fig. 4 This second opening 29 then offers greater freedom of movement for the switching unit 12 within the switching unit housing 14, since the contact part can then, even in this position of the switching unit 10, protrude from the switching unit housing 14 through the second opening 29 or at least partially protrude into the second opening 29. Thus, the design of the switching unit housing 14 with such a second opening 29 can be flatter than without such a second opening 29.

[0079] The inner diameter d1 of the first opening 28 is smaller than the outer diameter D3 of the bimetallic snap disc 16 and / or the spring snap disc 18, measured parallel to it. Likewise, the inner diameter d2 of the second opening 29 is smaller than the outer diameter D3 of the bimetallic snap disc 16 and / or the spring snap disc 18. Thus, although the contact part 20 is accessible from the outside through the openings 28 and 29 from opposite sides, the bimetallic snap disc 16 and the spring snap disc 18 cannot detach from the switch housing 14.

[0080] The inner diameter d 2 of the second opening 29 is smaller than the inner diameter d 1 of the first opening 28. However, the inner diameter d 2 of the second opening 29 should be larger than the outer diameter of the contact part 20.

[0081] The switching mechanism housing 14 is designed as a single piece and consists of a base body made of an electrically conductive material, for example, metal. The base body of the switching mechanism housing 14 has a bottom wall 30 and a side wall 32 integrally connected to the bottom wall. The bottom wall 30 forms the second housing side 24 of the switching mechanism housing 14. The second opening 29 is preferably designed as a central bore that is provided in the center of the bottom wall 30. The side wall 32 forms the housing circumferential side 26 of the switching mechanism housing 14. A free upper section 34 of the side wall 32 is bent towards a central axis 36, which forms the longitudinal axis of the contact part 20.

[0082] In principle, the upper section can be bent over along its entire circumference, so that the circumferential edge 38 of this bent upper section 34 defines the first opening 28 of the switchgear housing 14 in the radial direction along its entire circumference. However, to avoid wrinkling, it is advantageous if the upper section 34 of the side wall 32 has several separate, circumferentially distributed, bent segments 35, as shown in the top view in Fig. 2 shown.

[0083] In the Fig. 1 In the low-temperature position of the switch 10 shown, the spring-loaded snap disc 18 rests with its outer edge against the switch housing 14. More precisely, the spring-loaded snap disc 18 rests with its outer edge against an inner surface 40 of the bottom wall 30 facing the switch unit 12. In this position of the switch 10, the spring-loaded snap disc 18 carries the contact element 20. In this position of the switch 10, the bimetallic snap disc 16, on the other hand, is mounted in the switch housing 14 with virtually no force.

[0084] The two snap discs 16, 18 are preferably circular in shape and each has a centrally arranged through-hole 42, 44. The through-hole 42 centrally arranged in the bimetallic snap disc 16 is referred to here as the first through-hole. The through-hole 44 arranged in the spring snap disc 18 is referred to as the second through-hole.

[0085] The two snap discs 16, 18 are fitted over the contact part 20 from opposite sides with their respective through holes 42, 44. Thus, the contact part 20 penetrates both snap discs 16, 18 at a central point.

[0086] The contact part 20 has a base body 46, which is preferably solid and made of an electrically conductive material. The base body 46 is guided through the two through holes 42, 44.

[0087] Approximately in the middle, i.e., at about half its height, the contact part 20 has a support shoulder 48 projecting radially from the base body 46. The two snap discs 16, 18 rest against this support shoulder 48 from opposite sides. The bimetallic snap disc 16 is arranged on a first side of the support shoulder 48, which is Fig. 1 und 2 the upper side of the support shoulder 48. The spring-loaded snap disc 18 is arranged on a second side of the support shoulder 48 opposite the first side, which is in Fig. 1 und 2 the underside of the support shoulder 48 forms.

[0088] The contact part 20 is further equipped with locking elements 50, 52, by means of which the two snap discs 16, 18 are held on the contact part 20. The two locking elements 50, 52 project radially from the base body 46 of the contact part 20. The first locking element 50 is arranged on the first side of the support shoulder 48. The second locking element 52 is arranged on the opposite second side of the support shoulder 48.

[0089] The bimetallic snap disc 16 is arranged between the first locking element 50 and the support shoulder 48 and is held captive on the contact part 20 due to the radial projection of the first locking element 50 and the support shoulder 48.

[0090] The spring-loaded snap disc 18 is arranged between the second locking element 52 and the support shoulder 48 and is held captive on the contact part 20 due to the radial projection of the second locking element 52 and the support shoulder 48.

[0091] The contact part 20, together with the support shoulder 48 and the two locking elements 50, 52, is formed as a single piece. The support shoulder 48 and the two locking elements 50, 52 are therefore integrally formed with the base body 46 of the contact part 20.

[0092] In the Fig. 1 In the illustrated embodiment, the two locking elements 50, 52 are each designed as a circumferentially extending collar. The circumferentially extending collar forming the first locking element 50 projects obliquely upwards radially from the base body 46 of the contact part 20. The collar forming the second locking element 52 projects obliquely downwards radially from the base body 46 of the contact part 20.

[0093] Both collars can be formed relatively easily by forming a circumferential cut notch into the contact part 20. The cut notches are formed into the contact part after the two snap discs 16, 18 with their through holes 40, 42 have been placed over the contact part 20.

[0094] As an alternative to collars produced by cutting notches, the two locking elements 50, 52 can each have one or more retaining claws (not shown). Such retaining claws are also preferably integrally formed with the base body 46 of the contact part 20.

[0095] For the function of the switching mechanism 10, it is advantageous if the bimetallic snap disc 16 is held on the contact part 20 with more play than the spring-loaded snap disc 18. This ensures sufficiently free movement of the bimetallic snap disc 16. At the same time, the slightly smaller play between the spring-loaded snap disc 18 and the contact part 20 allows for the best possible electrical contact between these two components.

[0096] Of course, other forms of the switchgear housing 14 are possible. However, it is important that the contact part 20 moves away from the position in the switchgear housing when the snap discs 16, 18 snap shut. Fig. 1 The switchgear housing 14 can move downwards from the low-temperature position shown to the high-temperature position. For this to happen, sufficient space must be provided, particularly for the contact element 20, so that it does not collide with the bottom wall 30 when the switchgear 10 is in the high-temperature position. As already mentioned, this is made possible according to the invention by the opening 29 provided in the bottom wall 30.

[0097] In Fig. 3 and 4 Figure 1 is an embodiment of a temperature-dependent switch in which the switching mechanism 10 according to the invention can be used, shown in a schematic sectional view. The switch as a whole is designated by the reference numeral 100.

[0098] Fig. 3 indicates the low temperature setting of switch 100. Fig. 4 indicates the high-temperature position of switch 100.

[0099] Switch 100 indicates, according to the in Fig. 3 and 4 In the illustrated embodiment, a switch housing 56 is provided, which serves as an outer housing for the switching mechanism 10. The switching mechanism 10, together with its switching mechanism housing 14, is inserted into the switch housing 56. The switching mechanism 10 corresponds to the one shown in Fig. 1 embodiment shown.

[0100] The switch housing 56 comprises a pot-shaped lower part 58 and a lid part 60, which is held to the lower part 58 by a bent or crimped edge 62.

[0101] Both the lower part 58 and the lid part 60 are in the Fig. 3 and 4The illustrated embodiment is made of an electrically conductive material, preferably metal. An insulating film 64 is arranged between the lower part 58 and the cover part 60. The insulating film 64 provides electrical insulation between the lower part 58 and the cover part 60. The insulating film 64 also provides a mechanical seal, preventing liquids or contaminants from entering the housing interior.

[0102] Since the lower part 58 and the cover part 60 are each made of electrically conductive material, thermal contact can be established with an electrical device to be protected via their outer surfaces. These outer surfaces also serve as the external electrical connection for the switch 100. For example, the outer surface 61 of the cover part 60 can function as the first electrical connection, and the outer surface 59 of the lower part 58 can function as the second electrical connection.

[0103] On the outside of the lid part 60, as shown in Fig. 3 and 4 shown, another insulation layer 66 is arranged.

[0104] The switching mechanism 10 is clamped between the lower part 58 and the cover part 60. It is particularly important that the contact part 20 is aligned with a mating contact 70, which is located on the inside of the cover part 60. This mating contact 70 is also referred to here as the first stationary contact. The inside 71 of the lower part 58 serves as the second stationary contact.

[0105] In the Fig. 3 In the low-temperature position of switch 100 shown, the temperature-independent spring-loaded snap disc 18 is in its first configuration, and the temperature-dependent bimetallic snap disc 16 is in its low-temperature configuration. The spring-loaded snap disc 18 presses the contact part 20 through the first opening 28 against the mating contact 70. Switch 100 is thus in its closed position, in which an electrically conductive connection is established between the first stationary contact 70 and the second stationary contact 71 via the contact part 20 and the spring-loaded snap disc 18. The contact pressure between the contact part 20 and the first stationary contact 70 is generated by the spring-loaded snap disc 18. In this state, the bimetallic snap disc 16 is mounted in the switch housing 14 with virtually no force.

[0106] If the temperature of the device to be protected, and thus the temperature of the switch 100 and the bimetallic snap disc 16 located therein, rises to or above the switching temperature of the bimetallic snap disc 16, the bimetallic snap disc 16 snaps from its position in Fig. 3 The shown convex low-temperature position transforms into its concave high-temperature position, which in Fig. 4 As shown. During this snapping action, the bimetallic snap disc 16 rests with its outer edge against the first housing side 22 of the derailleur housing 14. More precisely, the bimetallic snap disc 16 rests against an inner surface 72 of the bent upper section 34 located inside the derailleur housing 14. This simultaneously bends the spring snap disc 18 downwards at its center, so that the spring snap disc 18 is released from its position in Fig. 3 shown, first stable geometric configuration in their in Fig. 4 The second geometrically stable configuration shown flips over.

[0107] In the case of the formation of the upper section 34 by several individual, extensively distributed segments 35, as is shown in Fig. 2 As shown, the aforementioned inner surface 72 is formed jointly by the undersides of the individual segments 35.

[0108] Fig. 4 This shows the high-temperature position of switch 100, in which it is open. The circuit is therefore interrupted.

[0109] When the device to be protected, and thus the switch 100 including the bimetallic snap disc 16, cools down again, the bimetallic snap disc 16 snaps back into its low-temperature position upon reaching the reset temperature, which is also referred to as the return temperature, as is the case, for example, in Fig. 3 This is shown. Thus, a reversible switching behavior can be implemented.

[0110] Of course, it is also possible to prevent the switch 100 from resetting to the high-temperature position after it has snapped into place by means of a corresponding locking mechanism. Such locking mechanisms, which are used particularly in single-use switches where resetting is to be prevented, are already known in numerous designs from the prior art.

[0111] It should also be mentioned that the in Fig. 3 and 4 The switch housing 56 shown is an exemplary switch housing. It is understood that the switching mechanism 10 according to the invention, particularly due to the provision of the extra switching mechanism housing 14, can be used in switch housings of completely different designs.

Claims

1. A temperature-dependent switching mechanism (10) for a temperature-dependent switch (100), having: - a temperature-dependent bimetal snap-action disc (16); - a temperature-independent snap-action spring disc (18); - an electrically conductive contact member (20) to which the bimetal snap-action disc (16) and the snap-action spring disc (18) are captively held, so that the bimetal snap-action disc (16), the snap-action spring disc (18), and the contact member (20) form a switching mechanism unit (12) captively held together; and - a switching mechanism housing (14) having a base body, in which the switching mechanism unit (12) is arranged and which captively holds the switching mechanism unit (12); wherein the base body of the switching mechanism housing (14) surrounds the switching mechanism unit (12) from a first housing side (22), a second housing side (24) opposite the first housing side (22), and a housing peripheral side (26) extending between and transverse to the first and second housing sides (22, 24), and wherein the switching mechanism housing (14) is configured as an at least partially open housing and comprises a first opening (28) in the base body on the first housing side (22), through which the contact member (20) is accessible from outside the switching mechanism housing (14), and a second opening (29) in the base body on the second housing side (24), through which the contact member (20) is accessible from outside the switching mechanism housing (14), characterized in that an inner diameter (d1) of the first opening (28) and an inner diameter (d2) of the second opening (29) are each smaller than an outer diameter (D3), measured parallel thereto, of the bimetal snap-action disc (16).

2. The temperature-dependent switching mechanism according to claim 1, wherein the contact member (20) permanently projects out of the switching mechanism housing (14) through the first opening (28) or is movable together with the bimetal snap-action disc (16) and the snap-action spring disc (18) within the switching mechanism housing (14) in such a way that the contact member (20) projects out of the switching mechanism housing (14) through the first opening (28) upon a corresponding movement.

3. The temperature-dependent switching mechanism according to claim 1, wherein the bimetal snap-action disc (16) is configured to snap from a low-temperature configuration into a high-temperature configuration upon exceeding a response temperature, and wherein the contact member (20) projects out of the switching mechanism housing (14) through the first opening (28) when the bimetal snap-action disc (16) is in its low-temperature configuration.

4. The temperature-dependent switching mechanism according to claim 3, wherein, when the bimetal snap-action disc (16) is in its high-temperature configuration, the contact member (20) is arranged in the second opening (29) or projects out of the switching mechanism housing (14) through the second opening (29).

5. The temperature-dependent switching mechanism according to one of the preceding claims, wherein an inner diameter (d1) of the first opening (28) and an inner diameter (d2) of the second opening (29) are each smaller than an outer diameter (D3), measured parallel thereto, of the snap-action spring disc (18).

6. The temperature-dependent switching mechanism according to one of the preceding claims, wherein the inner diameter (d2) of the second opening (29) is smaller than the inner diameter (d1) of the first opening (28).

7. The temperature-dependent switching mechanism according to one of the preceding claims, wherein the second opening (29) is formed as a centrally arranged hole in the second housing side (24) of the switching mechanism housing (14).

8. The temperature-dependent switching mechanism according to one of the preceding claims, wherein the switching mechanism housing (14) comprises a side wall (32) forming the housing peripheral side (26), and at least one upper portion (34) forming the first housing side (22).

9. The temperature-dependent switching mechanism according to claim 8, wherein the at least one upper portion (34) is formed by a free bent upper portion (34) of the side wall (32).

10. The temperature-dependent switching mechanism according to claim 8 or 9, wherein the at least upper portion (34) comprises a plurality of separate circumferentially distributed segments (35) forming the first housing side (22).

11. The temperature-dependent switching mechanism according to one of claims 8-10, wherein the bimetal snap-action disc (16) is configured to snap from a geometrically stable low temperature configuration to a geometrically stable high temperature configuration upon exceeding a response temperature, and wherein the bimetal snap-action disc (16) in its low temperature configuration is spaced from an inner surface (72) of the at least one upper portion (34) arranged inside the switching mechanism housing (14) and in its high temperature configuration bears against the inner surface (72) of the at least one upper portion (34).

12. The temperature-dependent switching mechanism according to one of the preceding claims, wherein the switching mechanism housing (14) is formed in one piece.

13. The temperature-dependent switching mechanism according to one of the preceding claims, wherein the base body of the switching mechanism housing (14) comprises an electrically conductive material.

14. A temperature-dependent switch (100) comprising a temperature-dependent switching mechanism (10) according to one of claims 1-13 and a switch housing (56) surrounding the switching mechanism (10) and having a first contact (70) and a second contact (71), wherein the switching mechanism (10) is configured to establish an electrical connection between the first and second contacts (70, 71) below a response temperature of the bimetal snap-action disc (16) and to interrupt the electrical connection upon exceeding the response temperature.

15. The temperature-dependent switch (100) according to claim 14, wherein the switching mechanism (10) is configured to press the contact member (20) through the first opening (28) against the first contact (70) below the response temperature of the bimetal snap-action disc (16).