Temperature-dependent switching device, temperature-dependent switch, and method for producing a temperature-dependent switching device

Abstract

Temperature-dependent switching mechanism (10) for a temperature-dependent switch (100), comprising: a temperature-dependent bimetallic snap disc (12) having a first through-hole (18); a temperature-independent spring snap disc (14) having a second through-hole (20); and an electrically conductive contact part (16) having a base body (22) extending through the first through-hole (18) and the second through-hole (20). The contact part (16) has a bearing shoulder (24) projecting radially from the base body (22), a first locking element (26) projecting radially from the base body (22) and arranged on a first side of the bearing shoulder (24), and a second locking element (28) projecting radially from the base body (22) and arranged on a second side of the bearing shoulder (24) opposite the first side.The temperature-dependent bimetallic snap disc (12) and the spring-loaded snap disc (14) are arranged between the locking elements (26, 28) and the support shoulder (14) and are held captive by these elements, but with some play, against the base body (22) of the contact part (16). The contact part is formed in one piece, with the base body (22) being integrally connected to the support shoulder (24), the first locking element (26), and the second locking element (28).

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 having such a temperature-dependent switching mechanism. Furthermore, the present invention relates to a method for producing a temperature-dependent switching mechanism that can be used in 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 protective device, so that below the response temperature of the switch, 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 is constructed in two parts. It has a lower part which is firmly connected to a cover part with an insulating film in between. The temperature-dependent switching mechanism arranged in the switch housing has a spring snap-action disk to which a movable contact part is attached, as well as a bimetallic snap-action disk placed over the movable contact part. The spring snap-action disk presses the movable contact part against a stationary counter-contact which is arranged on the inside of the switch housing on the cover part. With its outer edge, the spring snap-action disk is supported in the lower part of the switch housing, so that the electrical current flows from the lower part through the spring snap-action disk and the movable contact part into the stationary counter-contact and from there into the cover part.

[0006] 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.

[0007] 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, similar to a hysteresis. Therefore, if the temperature of the bimetallic snap-action disc rises above the response temperature of the bimetallic snap-action disc due to a temperature increase in the device to be protected, the bimetallic snap-action disc switches from its low-temperature configuration to its high-temperature configuration.The bimetal snap-action disc works against the spring snap-action disc in such a way that it lifts the movable contact part from the stationary counter-contact, so that the switch opens and the device to be protected is switched off and cannot heat up any further.

[0008] 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.

[0009] In its low-temperature configuration, the bimetallic snap-action disc is preferably mounted in the switch housing in a mechanically force-free manner, whereby the bimetallic snap-action disc is also not used to conduct the current. This has the advantage that the bimetallic snap-action disc has a longer service life and that the switching point, i.e., the response temperature of the bimetallic snap-action disc, remains unchanged even after many switching cycles.

[0010] In many temperature-dependent switches, the bimetallic snap-action disc is therefore 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.

[0011] In the switch known from DE 10 2011 119 632 B3, the bimetallic snap-action disc is therefore already 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.

[0012] 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 as bulk material. During switch manufacturing, the switch mechanism can then be installed into the switch housing as a captive unit in a single step. This simplifies switch production considerably.

[0013] 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 the two components. However, it has been shown that, particularly during bulk storage of the pre-manufactured switchgear as a semi-finished product, the welding or soldering device between the contact part and the spring-loaded snap-action disc can break. Such defective switchgears can then, of course, no longer be used.

[0014] DE 199 19 648 A1 also proposes a temperature-dependent switch whose switching mechanism can be produced in advance as a semi-finished product. In this switching mechanism, too, the bimetallic snap-action disc, the spring-loaded snap-action disc, and the contact part form a captive unit even before installation in the switch housing. This unit can be inserted into the switch housing as a whole during production of the switch and can be stored in advance as bulk material. In this switching mechanism, the contact part has a casing made of softer metal and a core made of electrically conductive, harder metal. The bimetallic snap-action disc and the spring-loaded snap-action disc are plugged onto the casing and molded into the softer metal of the casing. However, it has been found that this type of connection often leads to the bimetallic snap-action disc and / or the spring-loaded snap-action disc becoming accidentally detached from the contact part during storage of the switching mechanism.

[0015] Another option 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-action disc and the spring-loaded snap-action disc with a rivet. Depending on the design of the switch, this rivet can also form the movable contact part of the switching mechanism. The rivet is constructed in two parts and comprises a rivet bolt that interacts with a hollow rivet or a rivet bolt with an attached counterholder.

[0016] While this type of riveted connection between a spring-loaded snap-action disc and a bimetallic snap-action disc has proven to be a mechanically durable connection, the riveted connection does have other disadvantages. For example, the bimetallic snap-action disc is usually clamped tightly to the rivet, which can lead to deformation and thus malfunction of the bimetallic snap-action disc.

[0017] DE 10 2013 017232 A1 discloses a temperature-dependent switching mechanism according to the preamble of claim 1.

[0018] It is therefore an object of the present invention to provide a temperature-dependent switching mechanism that can be easily and inexpensively produced as a semi-finished product from as few components as possible and can be stored in bulk without being susceptible to damage that could lead to a defect in the switching mechanism. Furthermore, the present invention is based on the object of providing a method for producing such a temperature-dependent switching mechanism.

[0019] This object is achieved according to the invention by a temperature-dependent switching mechanism according to claim 1, comprising: a temperature-dependent bimetallic snap-action disc having a first through-hole; a temperature-independent spring snap-action disc having a second through-hole; and an electrically conductive contact part having a base body extending through the first through-hole and the second through-hole;wherein the contact part has a support shoulder projecting radially from the base body, a first locking element projecting radially from the base body and arranged on a first side of the support shoulder, and a second locking element projecting radially from the base body and arranged on a second side of the support shoulder opposite the first side, wherein the temperature-dependent bimetallic snap-action disc is arranged between the first locking element and the support shoulder and is held captively by the first locking element and the support shoulder, but with play, on the base body of the contact part; wherein the temperature-independent spring snap-action disc is arranged between the second locking element and the support shoulder and is held captively by the second locking element and the support shoulder, but with play, on the base body of the contact part, and wherein the contact part is formed in one piece and the base body is integrally connected to the support shoulder, the first locking element and the second locking element.

[0020] Furthermore, the above-mentioned object is achieved according to claim 14 by a method for producing a temperature-dependent switching mechanism, which comprises the following steps: Providing a temperature-dependent bimetallic snap-action disc having a first through-hole; providing a temperature-independent spring snap-action disc having a second through-hole; providing an electrically conductive contact part having a base body and a support shoulder projecting radially from the base body; passing the base body through the first through-hole so that the bimetallic snap-action disc is arranged on a first side of the support shoulder; passing the base body through the second through-hole so that the spring snap-action disc is arranged on a second side of the support shoulder opposite the first side;Forming a first part of the base body, which is arranged on the first side of the support shoulder, in order to produce a first locking element such that the temperature-dependent bimetallic snap-action disc is arranged between the first locking element and the support shoulder and is held captively but with play on the base body of the contact part by the first locking element and the support shoulder; and forming a second part of the base body, which is arranged on the second side of the support shoulder, in order to produce a second locking element such that the temperature-independent spring snap-action disc is arranged between the second locking element and the support shoulder and is held captively but with play on the base body of the contact part by the second locking element and the support shoulder.

[0021] The switching mechanism according to the invention has an electrically conductive contact part that is guided through through holes in the bimetallic snap-action disc and the spring-loaded snap-action disc. The contact part thus protrudes through both snap-action discs. It has a radially protruding support shoulder against which the two snap-action discs rest from opposite sides. Locking elements arranged on either side of this support shoulder hold the respective snap-action disc between the support shoulder and the respective locking element captively, but with play on the contact part. The contact part, together with the bimetallic snap-action disc and the spring-loaded snap-action disc, thus forms a captive unit that can be pre-produced as a semi-finished product and kept in stock as bulk material. It can then be inserted as a complete unit into a corresponding switch housing during switch assembly.

[0022] The locking elements for holding and locking the bimetallic snap-action disc and the spring-loaded snap-action disc are integrally connected to the base body of the contact piece. The locking elements are created by forming a respective part of the base body. The contact piece is thus formed as a single piece, and the base body of the contact piece is integrally connected to the support shoulder and the two locking elements.

[0023] Overall, the contact element, the bimetallic snap-action disc, and the spring-loaded snap-action disc combine to form a three-part switch mechanism, which is implemented as a captive unit. This three-part design offers the advantage of requiring as few components as possible, as well as a mechanically very stable and robust switch mechanism.

[0024] Unlike the switch known from DE 10 2011 119 632 B3, the welded or soldered connection between the spring snap-action disc and the contact part cannot be destroyed, as such a connection does not exist.

[0025] Even an unintentional release of the bimetal snap-action disc and / or the spring snap-action disc from the contact part, as described in DE 199 19 648 A1, is hardly possible due to the locking elements.

[0026] The one-piece construction of the contact part is advantageous both for mechanical reasons and in terms of its lower manufacturing costs compared to the two-piece riveted joints used in the switches known from DE 10 2007 014 237 A1 and DE 29 17 482 A1. Furthermore, the bimetallic snap-action disc and the spring-loaded snap-action disc are held with play to the base body of the contact part by means of the locking elements, so that undesirable stresses and resulting deformation of the two snap-action discs are hardly possible.

[0027] The above-mentioned task is thus completely solved.

[0028] According to one embodiment, the first locking element has at least one first retaining claw that protrudes radially from the base body and is integrally formed therewith, or a first flanged collar that protrudes radially from the base body and surrounds the circumference of the base body. Likewise, according to this embodiment, the second locking element has at least one second retaining claw that protrudes radially from the base body and is integrally formed therewith, or a second flanged collar that protrudes radially from the base body and surrounds the circumference of the base body.

[0029] One or more retaining claws can be provided for each locking element (first and second locking element). The retaining claws can form individual circumferential sections of the base body or extend around the entire circumference of the base body. These retaining claws can be designed as bent or flanged retaining claws.

[0030] Instead of retaining claws, a circumferential collar can also serve as the locking element. This collar can be created by flanging a pre-formed part on the base body of the contact part. Alternatively, the collar can also be created by a circumferential cut notch in the base body, through which the radially outer material of the base body is bent radially outward, forming the collar.

[0031] In this way, the two snap-action discs are held captive to the base body, but with some play. Manufacturing these locking elements is extremely simple. Because they are integrally connected to the base body, the locking elements are mechanically very stable.

[0032] According to a further embodiment, a first distance between an upper side of the contact part arranged on the first side of the support shoulder and an underside of the contact part arranged on the second side of the support shoulder is greater than a second distance between the first locking element and the second locking element.

[0033] In other words, the locking elements are arranged in an area between the free upper side and the free lower side of the contact part. Accordingly, the contact part can rest with its free upper side and lower side against corresponding mating contacts or mating contact surfaces without the locking elements coming into contact with the mating contacts or mating contact surfaces. This creates a precisely defined contact between the contact part and the mating contacts or mating contact surfaces, while also preventing damage to the locking elements.

[0034] According to a further embodiment, the bimetal snap-action disc is held on the base body with greater play than the spring snap-action disc.

[0035] The spring snap-action disc is therefore preferably clamped more tightly between the support shoulder and the second locking element than the bimetallic snap-action disc is between the support shoulder and the first locking element. The bimetallic snap-action disc thus has greater mobility relative to the contact part than the spring snap-action disc. This ensures the best possible electrical contact between the spring snap-action disc and the contact part, while also allowing sufficient mobility of the bimetallic snap-action disc, which is advantageous in terms of its service life.

[0036] Since the bimetallic snap-action disc, unlike the spring-action disc, is preferably not used as a current-carrying component of the switchgear, there does not need to be an overly tight clamping between the bimetallic snap-action disc and the contact part.

[0037] According to a further embodiment, the switching mechanism is designed to be rotationally symmetrical about a longitudinal axis of the contact part.

[0038] This makes it very easy to install the switch mechanism into a switch housing. It also allows for optimal force application from the two snap-action discs to the contact part, evenly distributed along the circumference.

[0039] According to a further embodiment, the first through-hole is arranged centrally in the bimetallic snap-action disc. Likewise, the second through-hole is preferably arranged centrally in the spring snap-action disc.

[0040] The bimetallic snap-action disc and the spring-action disc are preferably each circular disc-shaped. Furthermore, the bimetallic snap-action disc and the spring-action disc are preferably each bistable.

[0041] "Bistable" in this context means that both snap-action discs each have two different, stable geometric configurations / positions (used synonymously here), with the two stable configurations / positions of the bimetallic snap-action disc being temperature-dependent, and the two stable configurations / positions of the spring-action disc being temperature-independent. This ensures that the two snap-action discs remain stable in their respective positions after snapping from one position to the other, without undesired snapping back. Snapping of the switching mechanism therefore only occurs when the response temperature of the bimetallic snap-action disc is exceeded and the return temperature of the bimetallic snap-action disc is undershot. The spring-action disc snaps together with the bimetallic snap-action disc, forcing it into its other configuration / position.

[0042] According to a further embodiment, the derailleur further comprises a derailleur housing which holds the bimetallic snap-action disc, the spring snap-action disc and the contact part captively but with play.

[0043] This derailleur housing is not to be confused with the typical switch housing, which forms the outer housing of the switch. The derailleur housing used in this design is an additional housing in which the derailleur can be installed before it is installed in the switch housing.

[0044] In this way, the rear derailleur can already be pre-produced as a semi-finished product in the rear derailleur housing and then inserted into the switch housing together with the rear derailleur housing.

[0045] The derailleur housing has the advantage that the fragile components of the derailleur, such as the bimetallic snap disc and the spring-loaded snap disc, are protected during storage. On the other hand, the additional derailleur housing significantly simplifies installation of the derailleur in the switch housing, as the derailleur housing already allows for pre-positioning of the derailleur. Furthermore, the additional derailleur housing allows for the creation of an extremely pressure-resistant switch.

[0046] The derailleur housing preferably at least partially surrounds the bimetallic snap-action disc and the spring snap-action disc from a first housing side, a second housing side opposite the first housing side and a housing peripheral side extending between and transversely to the first and second housing sides, wherein the first housing side has an opening through which the contact part is accessible from outside the derailleur housing.

[0047] The stationary contact, which acts as a counterpart to the contact part, can therefore still be arranged on the switch housing, since the contact part protrudes beyond the aforementioned opening in the switch housing. Thus, a first electrical contact can be established between the contact part and the mating contact arranged on the switch housing. The second electrical contact between the switch housing and the second stationary contact, which is also arranged on the switch housing, can be established via the switch housing.

[0048] A diameter of the opening in the derailleur housing is preferably smaller than a diameter of the bimetallic snap disc measured parallel to it.

[0049] The bimetal snap disc is thus securely held in the derailleur housing and cannot come loose even in the event of a shock.

[0050] The derailleur housing is preferably constructed in one piece and is made of an electrically conductive material. The derailleur housing is particularly preferably made of metal.

[0051] The switch housing is preferably used as a current-carrying component in the switch. The spring-loaded snap-action disc is preferably supported on the inside of the switch housing, so that, when the switch is installed and in the closed position, the current flows from one terminal of the switch via the switch housing, the spring-loaded snap-action disc, and the contact element to the other terminal of the switch.

[0052] As already mentioned, the present invention relates not only to the switching mechanism itself, but also to the temperature-dependent switch in which such a temperature-dependent switching mechanism is used. The temperature-dependent switch comprises a switch housing surrounding the switching mechanism, which has a first electrical terminal and a second electrical terminal. The switching mechanism is configured to establish an electrical connection between the first and second electrical terminals below a response temperature of the bimetallic snap-action disc and to interrupt the electrical connection when the response temperature is exceeded.

[0053] 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.

[0054] Embodiments of the invention are illustrated in the drawings and explained in more detail in the following description. They show: Fig. 1 shows a schematic sectional view of the temperature-dependent switching mechanism according to a first embodiment of the present invention; Fig. 2 shows a schematic sectional view of the temperature-dependent switching mechanism according to a second embodiment of the present invention; Fig. 3 shows a schematic sectional view of the temperature-dependent switching mechanism according to a third embodiment of the present invention; Fig. 4 shows a schematic sectional view of the temperature-dependent switching mechanism according to a fourth embodiment of the present invention; Fig. 5 shows a schematic sectional view of an embodiment of the temperature-dependent switch according to the invention in its low-temperature position; Fig. 6 a schematic sectional view of the Fig. 5 shown embodiment of the temperature-dependent switch according to the invention in its high-temperature position; and Fig. 7 is a schematic representation to explain a manufacturing step in the manufacture of the switching mechanism according to the invention according to the Fig. 2 shown second embodiment.

[0055] Fig. 1-4 show various embodiments of the switching mechanism according to the invention, each in a schematic sectional view. The switching mechanism is designated in its entirety by reference numeral 10.

[0056] The switching mechanism 10 is a temperature-dependent switching mechanism. As explained in more detail below, the switching mechanism 10 switches between a low-temperature position and a high-temperature position depending on the temperature. Fig. 1-4 the low temperature position of the switching mechanism 10 is shown.

[0057] The switching mechanism 10 is constructed in three parts. It comprises a temperature-dependent bimetallic snap-action disc 12, a temperature-independent spring-action disc 14, and a contact part 16. The bimetallic snap-action disc 12 and the spring-action disc 14 are held captive on the contact part, but with play. The switching mechanism 10 can thus be pre-produced as a semi-finished product and then used as a complete unit in a corresponding switch, such as those used in Fig. 5 and 6 shown. Since the two snap-action discs 12, 14 are held captively on the contact part 16, an unintentional release of the two snap-action discs 12, 14 from the contact part 16 is prevented.

[0058] The two snap-action discs 12, 14 are preferably circular disc-shaped, each having a centrally located through-hole 18, 20. The through-hole 18 located centrally in the bimetallic snap-action disc 12 is referred to herein as the first through-hole. The through-hole 20 located in the spring snap-action disc 14 is referred to as the second through-hole.

[0059] The two snap-action discs 12, 14 are placed over the contact part 16 from opposite sides with their respective through holes 18, 20. Thus, the contact part 16 penetrates both snap-action discs 12, 14 at a central point. The contact part 16 has a base body 22, which is preferably solid and made of an electrically conductive material. This base body 22 extends through the two through holes 18, 20.

[0060] Approximately in the middle, i.e. approximately halfway up, the contact part 16 has a support shoulder 24 projecting radially from the base body 22. The two snap discs 12, 14 rest against this support shoulder 24 from opposite sides. The bimetallic snap disc 12 is arranged on a first side of the support shoulder 24, which Fig. 1-4 The spring snap-action disk 14 is arranged on a second side of the support shoulder 24 opposite the first side, which in Fig. 1-4 forms the underside.

[0061] Furthermore, locking elements 26, 28 are formed on the contact part 16, by means of which the two snap discs 12, 14 are held on the contact part 16. The two locking elements 26, 28 protrude radially from the base body 22 of the contact part 16. The first locking element 26 is arranged on the first side of the support shoulder 24. The second locking element 28 is arranged on the opposite, second side of the support shoulder 24.

[0062] The bimetallic snap-action disc 12 is arranged between the first locking element 26 and the support shoulder 24 and is held captive, but with play, on the base body 22 of the contact part 16 due to the radial projection of the first locking element 26 and the support shoulder 24 between the first locking element 26 and the support shoulder 24.

[0063] The spring snap-action disk 14 is arranged between the second locking element 28 and the support shoulder 24 and is held captive, but with play, on the base body 22 of the contact part 16 due to the radial projection of the second locking element 28 and the support shoulder 24 between the second locking element 28 and the support shoulder 24.

[0064] The contact part 16, together with the support shoulder 24 and the two locking elements 26, 28, is formed as a single piece. In other words, the support shoulder 24 and the two locking elements 26, 28 are formed integrally with the base body 22 of the contact part 16.

[0065] In the Fig. 1 In the first exemplary embodiment shown, the two locking elements 26, 28 are each designed as a circumferentially extending collar, each formed by a circumferentially extending cutting notch 30 and 32, respectively. The circumferentially extending collar forming the first locking element 26 projects radially upwards and obliquely from the base body 22 of the contact part 16. The collar forming the second locking element 28 projects radially downwards and obliquely from the base body 22 of the contact part 16.

[0066] Both collars can be formed relatively easily by forming a circumferential cut notch 30 or 32 into the contact part 16. The cut notches 30, 32 are formed into the contact part 16 after the two snap discs 12, 14 with their through holes 18, 20 have been slipped over the base body 22 of the contact part 16.

[0067] In the Fig. 2 In the second embodiment shown, the locking elements 26, 28 each have at least one retaining claw 34 or 36. Both locking elements 26, 28 can have either a radially encircling retaining claw 34, 36 extending over the entire circumference of the contact part. Such encircling retaining claws then form very similar locking elements to those shown in Fig. 1 collar shown.

[0068] Alternatively, it is possible for both locking elements 26, 28 to each have a plurality of such retaining claws 34, 36, which are arranged circumferentially spaced from one another on the contact part 16. Gaps then exist between these individual, circumferentially distributed retaining claws.

[0069] Regardless of whether the two retaining claws 34, 36 extend continuously over the entire circumference of the contact part or have several claw elements distributed over the circumference, the retaining claws 34, 36 are preferably manufactured by forming or flanging correspondingly pre-formed claw elements. Part of this manufacturing process is described in Fig. 7 shown schematically.

[0070] Fig. 7 shows in particular the flanging of the lower retaining claw 36, which later forms the second locking element 28, which serves to fasten the spring snap-action disc 14 to the contact part 16. In the initial state, the pre-formed retaining claws 34, 36 protrude upwards or downwards in the axial direction from the base body 22. They are flanged by a suitable press die 38. This press die 38 has a circumferentially arranged bevel 40 at its radially outer end, with which the press die 38 contacts the retaining claw 36 during the forming process. A counter-holder 42, acting as a counterpart to the press die 38, presses from the opposite side onto the support shoulder 24 of the contact part 16. The retaining claw 36 is thus bent or flanged by the press die 38. This is shown in Fig. 7 indicated by the arrows 44. During this process, the spring snap-action disk 14 preferably rests on a radially circumferential support surface 46.

[0071] The assembly and fixing of the bimetallic snap-action disc 12 is carried out in a similar manner. For this purpose, the contact part 16, together with the attached spring snap-action disc 14, is rotated 180° around an axis oriented orthogonally to the plane of the sheet, and the bimetallic snap-action disc is slipped over the base body 22 of the contact part 16 so that it is arranged on the opposite side of the support shoulder 24 compared to the spring snap-action disc 14. The retaining claw 34 can then be bent radially outward using the same press die 38, so that it, too, is finally fixed to the contact part 16.

[0072] The base body 22 of the contact part 16 is preferably convexly shaped on its upper side 48. The contact part 16 is preferably designed such that a distance d 1 between the upper side 48 and the lower side 50 of the contact part 16 is greater than a distance d 2 between the first locking element 26 and the second locking element 28.

[0073] Preferably, at least the upper side 48 of the contact part 16 projects upward relative to the first locking element 26. This is particularly advantageous because the contact part 16 comes into contact with its upper side 48 against a corresponding mating contact, and the locking elements 26, 28 do not cause a collision with the mating contact.

[0074] Furthermore, it is advantageous for the function of the switching mechanism 10 if the bimetallic snap-action disc 12 is held on the contact part 16 with greater play than the spring snap-action disc 14. This ensures sufficient freedom of movement of the bimetallic snap-action disc 12. At the same time, the slightly smaller play between the spring snap-action disc 14 and the contact part 16 ensures the best possible electrical contact between these two components.

[0075] Fig. 3 und 4 show further embodiments of the switching mechanism 10 according to the invention. The design of the bimetallic snap-action disk 12, the spring snap-action disk 14 and the contact part 16 corresponds to the Fig. 1 In addition, the rear derailleur 10 has the features shown in Fig. 3 und 4 The embodiments shown have a switching mechanism housing 52. In this switching mechanism housing 52, the unit consisting of the bimetallic snap-action disc 12, the spring snap-action disc 14, and the contact part 16 is held captive, but with play.

[0076] The derailleur housing 52 at least partially surrounds the bimetallic snap-action disc 12 and the spring snap-action disc 14 by a first housing side 54, a second housing side 56 opposite the first housing side 54, and a peripheral housing side 58 extending between and transverse to the first and second housing sides 54, 56. On the first housing side 54, an opening 60 is provided in the derailleur housing 52, through which the contact part 16 is accessible from outside the derailleur housing 52.

[0077] A diameter D 1 of the opening 60 is smaller than a diameter D 2 of the bimetallic snap-action disc 12 measured parallel thereto. Thus, although the contact part 16 is accessible from the outside through the opening 60, the bimetallic snap-action disc 12 cannot detach itself from the switching mechanism housing 52.

[0078] The derailleur housing 52 is preferably designed as a single piece and is made of an electrically conductive material, e.g., metal. The derailleur 10, including and excluding the derailleur housing 52, is preferably designed to be rotationally symmetrical about a longitudinal axis 62 of the contact part 16.

[0079] The two in Fig. 3 und 4 The embodiments of the rear derailleur 10 shown differ essentially in the shape of the rear derailleur housing 52. While the base 64 arranged on the second housing side 56 in the Fig. 4 shown embodiment is arched in section and forms a kind of convex dome, the bottom 64 in the in Fig. 3 The embodiment shown is essentially plate-shaped and has a pot-like bulge 66 in a central section.

[0080] Of course, other shapes of the switch housing 52 are possible. However, it is important that the contact part 16 deviates from the position shown in the figure when the snap discs 12, 14 snap over. Fig. 3 und 4 shown position downwards within the derailleur housing 52. The reason for this is particularly evident from the following explanations of the function of the Fig. 5 and 6 shown temperature-dependent switch.

[0081] In Fig. 5 and 6An embodiment of a temperature-dependent switch in which the switching mechanism 10 according to the invention can be used is shown in a schematic sectional view. The switch is designated in its entirety by the reference numeral 100.

[0082] Fig. 5 shows the low temperature position of switch 100. Fig. 6 shows the high temperature position of switch 100.

[0083] The switch 100 has, according to the Fig. 5 and 6 shown embodiment, a switch housing 68, which functions as a surrounding housing for the rear derailleur 10. The rear derailleur 10 is inserted into the switch housing 68 together with its rear derailleur housing 52. The rear derailleur 10 corresponds to the Fig. 3 shown embodiment. However, it is understood that the Fig. 4 shown derailleur can be inserted in an equivalent form into the switch housing 68 of the switch 100. Likewise, a derailleur 10 without derailleur housing 52, as is shown, for example, in Fig. 1 und 2 shown, can be inserted into the switch housing 68 of the switch 100 without changing the basic function of the switch 100.

[0084] The switch housing 68 comprises a pot-like lower part 70 and a cover part 72, which is held to the lower part 70 by a bent or flanged edge 74.

[0085] Both the lower part 70 and the cover part 72 are in the Fig. 5 and 6In the embodiment shown, the housing is made of an electrically conductive material, preferably metal. An insulating film 76 is arranged between the lower part 70 and the cover part 72. The insulating film 76 provides electrical insulation between the lower part 70 and the cover part 72. Likewise, the insulating film 76 provides a mechanical seal that prevents liquids or contaminants from entering the housing interior from the outside.

[0086] Since the lower part 70 and the cover part 72 in this embodiment are each made of electrically conductive material, thermal contact with an electrical device to be protected can be established via their outer surfaces. The outer surfaces also serve as the external electrical connection of the switch 100. For example, the outer surface 71 of the cover part 72 can function as the first electrical connection, and the outer side 73 of the lower part 70 can function as the second electrical connection.

[0087] On the outside of the cover part 72, as shown in Fig. 5 and 6 shown, a further insulation layer 78 may be arranged.

[0088] The derailleur 10 is clamped between the lower part 70 and the cover part 72. A spacer ring 80, against which the derailleur housing 52 rests circumferentially, serves to position the derailleur 10. It is particularly important that the contact part 16 is aligned with a mating contact 82 arranged on the inside of the cover part 72. This mating contact 82 is also referred to herein as the first stationary contact. The inside 75 of the lower part 70 serves as the second stationary contact.

[0089] In the Fig. 5 In the position shown, the switch 100 is in its low-temperature position, in which the temperature-independent spring snap-action disc 14 is in its first configuration and the temperature-dependent bimetallic snap-action disc 12 is in its low-temperature configuration. The spring snap-action disc 14 presses the contact part 16 against the mating contact 82. The switch 100 is thus in its closed position, in which an electrically conductive connection is established between the first stationary contact 82 and the second stationary contact 75 via the contact part 16 and the spring snap-action disc 14. The contact pressure between the contact part 16 and the first stationary contact 82 is generated by the spring snap-action disc 14. The bimetallic snap-action disc 12, in contrast, is almost force-free in this state.

[0090] If the temperature of the device to be protected and thus the temperature of the switch 100 and the bimetal snap-action disc 12 arranged therein increases to the switching temperature of the bimetal snap-action disc 12 or above this switching temperature, the latter snaps from its Fig. 5 shown convex low-temperature configuration into its concave high-temperature configuration, which is Fig. 6 is shown. During this snapping action, the bimetallic snap-action disc 12 rests with its outer edge on the first housing side 54 of the switchgear housing 52. With its center, the bimetallic snap-action disc 12 pulls the movable contact part 16 downwards and lifts the movable contact part 16 from the first stationary contact 82. As a result, the spring snap-action disc 14 simultaneously bends downwards at its center, so that the spring snap-action disc 14 is released from its Fig. 5 shown, first stable geometric configuration into its Fig. 6 shown, second geometrically stable configuration snaps over. Fig. 6 shows the high-temperature position of switch 100, in which it is open. The circuit is thus interrupted.

[0091] If the switching mechanism 10 does not have a switching mechanism housing 52, the bimetallic snap disk 12 is supported in the high-temperature position of the switch 100 on the cover part 72 with the insulating film 76 interposed.

[0092] When the device to be protected and thus the switch 100 including the bimetallic snap-action disc 12 cool down again, the bimetallic snap-action disc 12 snaps back into its low-temperature position when the switch-back temperature is reached, which is also referred to as the return temperature, as it is used, for example, in Fig. 5 This allows for reversible switching behavior.

[0093] Of course, it is also possible for a corresponding locking device to prevent the switch from switching back to the high-temperature position once it has snapped into place. Such locking devices, which are used particularly in one-shot switches where switching back is to be prevented, are already known in numerous prior art designs.

[0094] Finally, it should be noted that the switching mechanism 10 according to the invention, as shown for example in Fig. 1-4 shown in different embodiments, can also be used in other types of temperature-dependent switches. Fig. 5 and 6 show only one possible design of a temperature-dependent switch in which the switching mechanism 10 according to the invention can be used.

Claims

1. A temperature-dependent switching mechanism (10) for a temperature-dependent switch (100), having: - a temperature-dependent bimetal snap-action disc (12) comprising a first through hole (18); - a temperature-independent snap-action spring disc (14) comprising a second through hole (20); and - an electrically conductive contact member (16) comprising a main body (22) that passes through the first through hole (18) and the second through hole (20); wherein the contact member (16) comprises a support shoulder (24) projecting radially from the main body (22), a first locking element (26) projecting radially from the main body (22) and being arranged on a first side of the support shoulder (24), and a second locking element (28) projecting radially from the main body (22) and being arranged on a second side of the support shoulder (24) opposite the first side, wherein the temperature-dependent bimetal snap-action disc (12) is arranged between the first locking element (26) and the support shoulder (24) and is held captive, but with clearance, on the main body (22) of the contact member (16) by the first locking element (26) and the support shoulder (24), wherein the temperature-independent snap-action spring disc (14) is arranged between the second locking element (28) and the support shoulder (14) and is held captive, but with clearance, on the main body (22) of the contact member (16) by the second locking element (28) and the support shoulder (24), characterized in that the contact member is integrally formed and the main body (22) is integrally connected to the support shoulder (24), the first locking element (26) and the second locking element (28).

2. The temperature-dependent switching mechanism according to claim 1, wherein the first locking element (26) comprises at least one first retaining claw (34) projecting radially from the main body (22) and formed integrally therewith, or a first collar projecting radially from the main body (22) and surrounding the circumference of the main body (22), and wherein the second locking element (28) comprises at least one second retaining claw (36) projecting radially from the main body (22) and formed integrally therewith, or a second collar projecting radially from the main body (22) and surrounding the circumference of the main body (22).

3. The temperature-dependent switching mechanism according to any one of the preceding claims, wherein a first distance (d1) between an upper side (48) of the contact member (16) arranged on the first side of the support shoulder (24) and a lower side (50) of the contact member (16) arranged on the second side of the support shoulder (24) is larger than a second distance (d2) between the first locking element (26) and the second locking element (28).

4. The temperature-dependent switching mechanism according to any of the preceding claims, wherein the bimetal snap-action disc (12) is held on the main body (22) with larger clearance than the snap-action spring disc (14).

5. The temperature-dependent switching mechanism according to any one of the preceding claims, wherein the switching mechanism (10) is configured rotationally symmetrical about a longitudinal axis (62) of the contact member (16).

6. The temperature-dependent switching mechanism according to any one of the preceding claims, wherein the first through hole (18) is arranged centrally in the bimetal snap-action disc (12), and wherein the second through hole (20) is arranged centrally in the snap-action spring disc (14).

7. The temperature-dependent switching mechanism according to any of the preceding claims, wherein the bimetal snap-action disc (12) and the snap-action spring disc (14) are each circular disc-shaped.

8. The temperature-dependent switching mechanism according to any one of the preceding claims, wherein the snap-action spring disc (14) is configured as a bistable snap-action spring disc (14) having two temperature-independent stable geometric configurations, and wherein the bimetal snap-action disc (12) is configured as a bistable bimetal snap-action disc (12) having two temperature-dependent stable geometric configurations.

9. The temperature-dependent switching mechanism according to any of the preceding claims, having a switching mechanism housing (52) which holds the bimetal snap-action disc (12), the snap-action spring disc (14) and the contact member (16) captive but with clearance.

10. The temperature-dependent switching mechanism according to claim 9, wherein the switching mechanism housing (52) surrounds the bimetal snap-action disc (12) and the snap-action spring disc (14) from a first housing side (54), a second housing side (56) opposite the first housing side (54), and a housing peripheral side (58) extending between and transverse to the first and second housing sides, the first housing side (54) having an opening (60) through which the contact member (16) is accessible from outside the switching mechanism housing (52).

11. The temperature-dependent switching mechanism according to claim 10, wherein a diameter (D1) of the opening (60) is smaller than a diameter (D2) of the bimetal snap-action disc (12) measured parallel thereto.

12. The temperature-dependent switching mechanism according to any one of claims 9-11, wherein the switching mechanism housing (52) is integrally formed and comprises an electrically conductive material.

13. A temperature-dependent switch (100) comprising a temperature-dependent switching mechanism (10) according to any one of claims 1-12 and a switch housing (68) surrounding the switching mechanism (10) and comprising a first electrical terminal (71) and a second electrical terminal (73), wherein the switching mechanism (10) is configured to establish an electrical connection between the first and second electrical terminals (71, 73) below a response temperature of the bimetal snap-action disc (12) and to interrupt the electrical connection upon exceeding the response temperature.

14. A method of manufacturing a temperature-dependent switching mechanism (10) comprising: - providing a temperature-dependent bimetal snap-action disc (12) comprising a first through hole (18); - providing a temperature-independent snap-action spring disc (14) comprising a second through hole (20); - providing an electrically conductive contact member (16) comprising a main body (22) and a support shoulder (24) projecting radially from the main body (22); - passing the main body (22) through the first through hole (18) so that the bimetal snap-action disc (12) is arranged on a first side of the support shoulder (24); - passing the main body (22) through the second through hole (20) so that the snap-action spring disc (14) is arranged on a second side of the support shoulder (24) opposite the first side; - forming a first portion of the main body (22) arranged on the first side of the support shoulder (24) to create a first locking element (26) such that the temperature-dependent bimetal snap-action disc (12) is arranged between the first locking element (26) and the support shoulder (24) and is held captive, but with clearance, to the main body (22) of the contact member (16) by the first locking element (26) and the support shoulder (24); and - forming a second portion of the main body (22) arranged on the second side of the support shoulder (24) to create a second locking element (28) such that the temperature-independent snap-action spring disc (14) is arranged between the second locking element (28) and the support shoulder (24) and is held captive, but with clearance, to the main body of the contact member (16) by the second locking element (28) and the support shoulder (24).

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