Temperature-dependent switch

Abstract

Temperature-dependent switch (10) comprising: a switch housing (12) with a lower part (16) and a cover part (18) closing the lower part (16); a contact carrier element (50) arranged in the switch housing (12) and having a contact surface (46), wherein at least one section of the contact carrier element (50) is fixed in position by an interaction of the lower part (16) and the cover part (18);and a temperature-dependent switching mechanism (14) which is arranged in the switch housing (12) and has a movable contact part (40) which interacts with the contact surface (46) arranged on the contact carrier element (50), wherein the switching mechanism (14) is configured to switch temperature-dependently between a low-temperature position, in which it presses the movable contact part (40) into contact with the contact surface (46) and thus establishes an electrical connection between a first electrical external terminal (56) of the switch (10) and a second electrical external terminal (58) of the switch (10), and a high-temperature position, in which it keeps the movable contact part (40) spaced away from the contact surface (46) and thus interrupts the electrical connection between the first electrical external terminal (56) and the second electrical external terminal (58).

Description

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

[0002] Temperature-dependent switches are already known in many different forms. Examples of temperature-dependent switches are known from DE 10 2018 100 890 B3, DE 10 2009 030 353 B3, DE 197 27 383 A1, and DE 197 27 197 A1.

[0003] Such temperature-dependent switches are used in a conventional manner to monitor the temperature of a device. For this purpose, the switch is brought into thermal contact with the device to be protected, for example, via one of its outer surfaces, so that the temperature of the device to be protected influences the temperature of the switching mechanism located inside the switch.

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

[0005] In the switch known from DE 10 2018 100 890 B3, the switching mechanism is arranged inside a switch housing. The switch housing is a closed housing in which the switching mechanism is sealed from the outside. The switch housing is constructed in two parts. It has a lower part, which is closed by a cover part. The cover part is attached to the lower part. For this purpose, the lower part has a raised, circumferential edge, the free upper edge of which is bent or flanged onto the cover part.

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

[0007] The temperature-dependent switching behavior of the switching mechanism is primarily due to the temperature-dependent bimetallic element, which in the switch known from DE 10 2018 100 890 B3 is disc-shaped and often referred to as a bimetallic snap-action disc. This bimetallic element is usually designed as a multi-layer, active, sheet-metal component consisting of two, three, or four interconnected components with different thermal expansion coefficients. The connection between the individual layers of metals or metal alloys in such bimetallic elements is usually materially bonded or positively bonded and is achieved, for example, by rolling.

[0008] Such a bimetallic element exhibits a first stable geometric configuration (low-temperature configuration) at low temperatures, below the response temperature of the bimetallic element, and a second stable geometric configuration (high-temperature configuration) at high temperatures, above the response temperature of the bimetallic element. Depending on the temperature, the bimetallic element jumps from its low-temperature configuration to its high-temperature configuration in a hysteresis manner.

[0009] If the temperature of the bimetallic element rises above its response temperature due to a temperature increase in the device to be protected, the bimetallic element switches from its low-temperature configuration to its high-temperature configuration. The bimetallic element works against the spring element to lift the movable contact part from the stationary counter-contact, causing the switch to open and the device to be protected to be switched off and prevent it from heating up further.

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

[0011] In its low-temperature configuration, the bimetallic element is preferably mounted in the switch housing without mechanical forces, whereby the bimetallic element is also not used to conduct the current. This has the advantage that the bimetallic element has a longer service life and that the switching point, i.e., the response or switching temperature of the bimetallic element, remains unchanged even after many switching cycles.

[0012] For proper functioning of such temperature-dependent switches, it is of paramount importance that the individual components of the temperature-dependent switching mechanism and the switch housing are precisely matched to one another. In particular, it is important that the height of the interior of the switch housing is precisely matched to the height of the switching mechanism in the low-temperature position, so that, for example, the contact pressure between the moving contact part and the stationary counter contact is correctly adjusted. This also influences the contact resistances that arise at the transitions between the individual components of the switching mechanism and thus also affects the performance of the switch.

[0013] For these reasons, the individual components of such a temperature-dependent switch must be manufactured to very tight tolerances and dimensionally matched to one another with great precision. Accordingly, very precise pre-inspections of the individual switch components are necessary. In some cases, it is also necessary to manually rework individual components or, depending on the manufacturing tolerances, to manually select suitable component pairings in order to maintain the overall tolerances. This complicates the automated assembly of such temperature-dependent switches.

[0014] In the switch known from DE 10 2018 100 890 B3, the height of the interior of the switch housing is determined in particular by the use of a spacer ring, which is arranged inside the switch housing between the base and the cover, keeping these two parts at a distance. By using spacer rings of different heights, the height of the housing interior and thus the contact pressure can be adjusted according to customer requirements. This can also be used to compensate for the manufacturing tolerances of the switch components. However, the height of the spacer ring then usually has to be manually adjusted to the manufacturing tolerances of the switch components.

[0015] There is therefore still scope for further improvements. In particular, the manufacturability of the switch can be improved, its assembly simplified, and a higher level of automation achieved.

[0016] It is therefore an object of the present invention to provide a temperature-dependent switch in which, in particular, the aforementioned aspects are further improved. This is intended, in particular, to simplify the assembly process and enable variable adaptation to specific customer requirements, for example, regarding the adjustment of contact resistances between the switching components.

[0017] This object is achieved according to the invention by a temperature-dependent switch which has the following components: a switch housing having a lower part and a cover part closing the lower part; a contact carrier element arranged in the switch housing and having a contact surface, wherein at least a portion of the contact carrier element is fixed in position by an interaction of the lower part and the cover part;and a temperature-dependent switching mechanism which is arranged in the switch housing and has a movable contact part which interacts with the contact surface arranged on the contact carrier element, wherein the switching mechanism is designed to switch in a temperature-dependent manner between a low-temperature position, in which it presses the movable contact part into contact with the contact surface and thus establishes an electrical connection between a first electrical external terminal of the switch and a second electrical external terminal of the switch, and a high-temperature position, in which it keeps the movable contact part spaced from the contact surface and thus interrupts the electrical connection between the first electrical external terminal and the second electrical external terminal. ;

[0018] In the switch according to the invention, the stationary contact surface (here referred to as "contact surface"), which interacts with the movable contact part in the low-temperature position of the switching mechanism, is, unlike in most previously known switches, not arranged on the cover part, but on a separate contact carrier element which is arranged in the switch housing and is fixed in position by an interaction of the lower part and the cover part.

[0019] ""Positionally fixed by the interaction of the lower part and the cover part" means that the contact carrier element is fixed in its position by the interaction of both switch housing components (cover part and lower part). The contact carrier element is therefore only fixed in its position when the two switch housing components are connected to each other. Only then do the two switch housing components jointly exert a force on the contact carrier element, thereby fixing it in its position.

[0020] The additional contact carrier element provided according to the invention offers various advantages. Firstly, the mechanical stability of the switch assembly is improved by providing an additional contact carrier element. Secondly, the contact pressure with which the movable contact part is pressed against the contact surface in the low-temperature position of the switch mechanism can be very easily determined or adjusted by means of a correspondingly adjustable shape of the contact carrier element. A particularly advantageous feature is that this type of contact pressure adjustment can be performed almost independently of the shape of the base and cover of the switch housing.By selecting differently shaped contact carrier elements, it is possible, for example, to realize different contact pressures and thus also different contact resistances in one and the same switch housing according to customer requirements, without having to change the shape of the base and cover parts of the switch housing.

[0021] The contact carrier element also makes it relatively easy to compensate for manufacturing tolerances in the switchgear components, for example, by adjusting the shape of the contact carrier element or by making it elastic or springy. The preliminary checks mentioned above regarding the manufacturing tolerances of the individual housing components or switchgear components can thus be eliminated or at least reduced to a minimum.

[0022] Furthermore, the provision of the contact carrier element also offers the advantage that one or both external terminals can be welded to the cover part, which would otherwise be impossible or difficult, since the stationary mating contact would usually become detached from the cover part due to heat development. However, since the contact surface is now no longer located on the cover part but on the contact carrier element, this problem is also eliminated.

[0023] The switch according to the invention can be manufactured both manually and fully automatically. Fully automated production is also simplified by the contact carrier element for the reasons mentioned above.

[0024] The above-mentioned task is thus completely solved.

[0025] According to one embodiment, the switching mechanism is either (i) arranged between the contact carrier element and the lower part and the contact carrier element is electrically conductively connected to the cover part, or (ii) the switching mechanism is arranged between the contact carrier element and the cover part and the contact carrier element is electrically conductively connected to the lower part.

[0026] In other words, the switching mechanism is located between one of the two housing components (cover or base) and the contact carrier element. The contact carrier element thus acts as a kind of additional cover or base that interacts with the switching mechanism.

[0027] If the switching mechanism according to alternative (i) is arranged between the contact carrier element and the lower part, the electrically conductive connection between the contact carrier element and the cover part is preferably realized by the contact carrier element resting against the cover part. However, if the switching mechanism according to alternative (ii) is arranged between the contact carrier element and the cover part, the electrically conductive connection between the contact carrier element and the lower part is preferably realized by the contact carrier element resting against the lower part.

[0028] Viewed the other way around, the contact carrier element is arranged between the switching mechanism and the cover part according to alternative (i) and between the switching mechanism and the lower part according to alternative (ii).

[0029] According to a further embodiment, the at least one section of the contact carrier element, which is fixed in position by the interaction of the lower part and the cover part, has an outer edge of the contact carrier element and a central region of the contact carrier element is spaced apart from both the lower part and the cover part.

[0030] In other words, the contact carrier element is preferably fixed in position at the edge by the interaction of the lower part and the cover part. Particularly preferably, the at least one section of the contact carrier element has a radially outer edge of the contact carrier element. This has the advantage of the most space-saving edge-mounting of the contact carrier element, while the central middle region of the contact carrier element is freely accessible to the switching mechanism and can be shaped relatively freely according to the desired customer specifications with regard to contact pressure and contact resistance. Because the central region of the contact carrier element is spaced apart from both the lower part and the cover part, this central region is designed to be flexible or resilient, which ensures optimal tolerance compensation.

[0031] According to a further embodiment, the contact carrier element, in particular an outer edge of the contact carrier element, is clamped directly or indirectly between the lower part and the cover part.

[0032] Such a clamping arrangement between the base and cover makes it particularly easy to fix the position of the contact carrier element. The contact carrier element can thus be easily inserted into the desired location inside the switch housing during switch assembly, allowing the switch housing to be closed by attaching the cover to the base, or vice versa. The contact carrier element does not impose any additional effort on the assembly process. In fact, the aforementioned advantages of the contact carrier element actually reduce the assembly effort.

[0033] In this case, "indirectly clamped" means that the contact carrier element is clamped by the cover and base sections together, but it does not necessarily have to be directly in contact with these two switch housing components. Additional housing components or elements can be arranged between them.

[0034] According to one embodiment, the temperature-dependent switching mechanism has a first spring element cooperating with the movable contact part and a bimetallic element cooperating with the movable contact part.

[0035] The first spring element is preferably designed as a temperature-independent, circular-disk-shaped spring disk. The bimetallic element is preferably designed as a temperature-dependent, circular-disk-shaped bimetallic disk. The contact carrier element is also preferably circular in shape when viewed from above.

[0036] According to one embodiment, the contact carrier element is designed like a cover and has a thinner wall thickness than the cover part.

[0037] According to this design, the contact carrier element acts as a kind of lower cover, which is arranged inside the switch housing between the cover part and the lower part and on which the (stationary) contact surface is located. The smaller wall thickness compared to the cover part has the advantage that the contact carrier element can be designed to be significantly more flexible or elastic than the cover part. In other words, the cover part still serves as the main protection and mechanical stability support, while the contact carrier element can be designed with relatively thin walls to allow for variable adaptation to the shape of the switching mechanism.

[0038] According to a further embodiment, the switching mechanism has the above-mentioned first spring element, which in the low-temperature position of the switching mechanism exerts a first spring force by which the movable contact part is pressed against the contact surface.

[0039] This first spring element is preferably a spring-loaded snap-action disc, as is commonly used in the switching mechanisms of such temperature-dependent switches. The first spring element is preferably used as a current-carrying component in the low-temperature position of the switching mechanism.

[0040] According to a further embodiment, the contact carrier element has a second spring element which, in the low-temperature position of the switching mechanism, exerts a second spring force by which the contact surface is pressed against the movable contact part.

[0041] The first spring force exerted by the first spring element is preferably opposite to the second spring force exerted by the second spring element.

[0042] According to this embodiment, the contact carrier element can comprise the second spring element or be formed entirely by it. In other words, the contact carrier element can also be designed entirely as a (second) spring element. Regardless of whether the contact carrier element comprises the second spring element or is formed entirely by it, such a resilient design of the contact carrier element has the advantage that it can significantly increase the contact pressure with which the movable contact part is pressed against the contact surface in the low-temperature position of the switching mechanism.

[0043] Unlike conventional temperature-dependent switches, the switch according to the invention employs two opposing springs, both of which ensure that the movable contact part is pressed against the contact surface arranged on the contact carrier element in the low-temperature position of the switch. This increased contact pressure reduces the contact resistance between the movable contact part and the contact surface, thereby increasing the performance of the switch.

[0044] The springing or springy design of the contact carrier element further improves the previously mentioned mechanical tolerance compensation which is effected by the contact carrier element.

[0045] The second spring force caused by the second spring element in the contact carrier element is preferably greater in magnitude than the first spring force caused by the first spring element belonging to the switching mechanism.

[0046] This has the advantage that the contact pressure is predominantly generated by the second spring element. This, in turn, is particularly advantageous in that the opening force required to open the switching mechanism—i.e., to move the switching mechanism from its low-temperature position to its high-temperature position—can be lower than usual. To open the switching mechanism, the first spring force generated by the first spring element must be overcome. This is typically achieved by a bimetallic element included in the switching mechanism.

[0047] As far as the spring travel is concerned, the first spring element preferably has a greater spring travel than the second spring element.

[0048] This has the advantage that the second spring element does not yield too much when the switching mechanism opens, i.e., when switching from the low-temperature position to the high-temperature position, and moves behind the moving contact part. Thus, despite the two spring elements working against each other, effective opening of the switching mechanism is achieved when the response temperature is reached.

[0049] Preferably, in the high-temperature position of the switching mechanism, the bimetallic element exerts an opening force on the movable contact part which is opposite to the first spring force and is greater in magnitude than the first spring force.

[0050] When the response temperature is reached, the bimetallic element snaps into its high-temperature configuration and lifts the movable contact part from the contact surface arranged on the contact carrier element, counter to the spring force exerted by the first spring element.

[0051] According to a further embodiment, the first electrical external connection of the switch is arranged on the outside of the cover part and the second electrical external connection of the switch is arranged on the outside of the lower part.

[0052] This ensures easy electrical connection of the temperature-dependent switch.

[0053] According to a further embodiment, the switch further comprises an insulating film which is arranged between the lower part and the contact carrier element.

[0054] The contact carrier element is thus effectively electrically insulated from the lower part.

[0055] Preferably, the contact carrier element and the lower part are each made of an electrically conductive material.

[0056] According to a further embodiment, the lower part has a free upper edge which is flanged or bent over onto the cover part.

[0057] This results in the simplest and most stable type of fastening between the lower part and the cover part, as is known, for example, from DE 10 2018 100 890 B3.

[0058] It is understood that the features mentioned above and those to be explained below can be used not only in their respective specified combinations, but also in other combinations or on their own, without departing from the scope of the present invention.

[0059] Embodiments of the invention are illustrated in the drawings and explained in more detail in the following description. They show: Fig. 1 is a schematic sectional view of the temperature-dependent switch according to a first embodiment, wherein the switch is in its low-temperature position; Fig. 2 is a schematic sectional view of the Fig. 1 shown temperature-dependent switch, wherein the switch is in its high-temperature position; Fig. 3 is a schematic sectional view of the temperature-dependent switch according to a second embodiment, wherein the switch is in its low-temperature position; Fig. 4 is a schematic sectional view of the temperature-dependent switch according to a third embodiment, wherein the switch is in its low-temperature position; and Fig. 5 is a schematic sectional view of the temperature-dependent switch according to a fourth embodiment, wherein the switch is in its low-temperature position.

[0060] Fig. 1-5 show four different embodiments of the switch according to the invention, each in a schematic sectional view. The switch is designated in its entirety by reference numeral 10.

[0061] The switch according to the first embodiment shows Fig. 1 the low temperature position of switch 10 and Fig. 2 the high temperature position of switch 10.

[0062] The switch 10 is rotationally symmetrical and has a circular shape when viewed from above. The switch 10 has a switch housing 12 in which a temperature-dependent switching mechanism 14 is arranged. The switch housing 12 comprises a pot-shaped lower part 16 and a cover part 18, which is held to the lower part 16 by a bent or flanged free upper edge 20.

[0063] The lower part 16 and the cover part 18 are made of an electrically conductive material, preferably metal. In the presently shown embodiment, the lower part 16 is a deep-drawn steel housing, which results in comparatively high pressure resistance. An insulating film 22 is arranged between the lower part 16 and the cover part 18, which serves to electrically insulate the two switch housing components 16, 18.

[0064] The upper edge 20 of the lower part 16 is bent radially inward in such a way that it presses the cover part 18 toward a circumferential shoulder 24 provided in the lower part 16. The cover part 18 thus completely closes the lower part 16. In addition to providing electrical insulation, the insulating film 22 also provides sufficient mechanical sealing between the lower part 16 and the cover part 18, so that the interior of the switch housing 12 is sealed from the outside. This prevents liquids or contaminants from entering the housing interior.

[0065] The switching mechanism 14 arranged inside the switch housing 12 has a temperature-independent spring element 26 and a temperature-dependent bimetallic element 28. The spring element 26 is preferably designed as a circular disk-shaped spring disk. Particularly preferably, the spring element 26 is designed as a bistable spring disk, which has two temperature-independent, stable geometric configurations. Fig. 1 Their first geometric configuration is shown. In Fig. 2 their second geometric configuration is shown.

[0066] The temperature-dependent bimetallic element 28 is preferably designed as a bimetallic disc which has two temperature-dependent configurations, a geometric low-temperature configuration (see Fig. 1 ) and a high-temperature geometric configuration (see Fig. 2 ).

[0067] In the Fig. 1 In the low-temperature position of the switching mechanism 14 shown, the spring element 26 rests with its edge 30 on a support surface 34 projecting upwards from the inner base surface 32 of the lower part. The inner base surface 32 is essentially concave and, at the point where the edge 30 of the spring element rests in the low-temperature position of the switching mechanism 14, is slightly raised compared to the central area of ​​the inner base surface 32. The bimetallic element 28 rests with its edge 36 in the Fig. 1 shown low temperature position of the switching mechanism 14 on the spring element 26.

[0068] The spring element 26 is secured at its center 38 to a movable contact part 40 of the switching mechanism 14. The movable contact part 40 is preferably connected to the spring element 26 in a materially bonded and / or form-fitting manner. For example, the contact part 40 is welded or soldered to the spring element 26.

[0069] The bimetallic element 28 can also be fixed to the movable contact part 40 by its center 42. However, the bimetallic element 28 can also be loosely connected to the contact part 40 by placing its centrally arranged opening over the contact part 40 and resting from above with its center or the inner edge surrounding the opening on a support shoulder 44 provided on the contact part 40.

[0070] The movable contact part 40 acts in the Fig. 1 In the low-temperature position of the switching mechanism 14 shown, the spring element 26 engages with a contact surface 46 formed on the underside of a contact part 48. In this low-temperature position of the switching mechanism 14, the spring element 26 presses the movable contact part 40 from below against the contact surface 46 of the contact part 48.

[0071] The contact part 48 is arranged on a contact carrier element 50, which is fixed to the Fig. 1 and 2shown embodiment is designed in a cover-like manner. This cover-like contact carrier element 50 is also made of electrically conductive material and preferably has a thinner wall thickness than the cover part 18 of the switch housing 12 arranged above it.

[0072] The contact carrier element 50 rests in the region of its outer edge 52 on the shoulder 24 provided inside the lower part 16, with the insulating film 22 interposed between it. The upper side of the contact carrier element 16 rests in the region of its outer edge 52 on the underside of the cover part 18. The outer edge 52 of the contact carrier element 50 is thus fixed in position by the interaction of the lower part 16 and the upper part 18, in that it is clamped between the lower part 16 and the cover part 18.

[0073] The central region 54 of the contact carrier element 50 is spaced apart from both the lower part 16 and the upper part 18 within the switch housing 12. The central region 54 of the contact carrier element 50 is thus movable to a limited extent within the switch housing 12, depending on the elasticity of the contact carrier element 50.

[0074] In the Fig. 1 and 2 In the first embodiment shown, the contact carrier element 50 forms a type of lower cover, which is arranged between the cover part 18 and the switching mechanism 14. In the low-temperature position of the switch 10 (see Fig. 1 ), the switching mechanism 14 rests with its movable contact part 40 on the contact carrier element 50. In this switching position of the switching mechanism 14, the contact carrier element 50 accordingly exerts a force on the movable contact part 40 that is opposite to the force exerted by the spring element 26 on the movable contact part 40.

[0075] Depending on the shape of the contact carrier element 50, the contact pressure between the movable contact part 40 and the contact surface 46 can be adjusted. For example, if a contact carrier element is used that is more strongly curved upwards in its central region 54, the contact pressure can be reduced compared to a contact carrier element 50 that is comparatively flatter in its central region 54. This also allows corresponding manufacturing tolerances of the switching mechanism components 26, 28, 40 and the housing components 16, 18 to be compensated.

[0076] The rear derailleur 14 is in the Fig. 1 shown low-temperature position, an electrically conductive connection is established between a first electrical external connection 56 and a second electrical external connection 58. In the present exemplary embodiment, the top side of the cover part 18 serves as the first electrical external connection 56. In the present exemplary embodiment, a welding connection ring which is soldered or welded to the lower part 16 of the switch housing 12 serves as the second electrical external connection 58. In the low-temperature position of the switch 10, an electrical current can thus flow from the first external connection 56 through the cover part 18 into the contact carrier element 50 and from there via the contact part 48 into the contact part 40 and via the spring element 26 into the lower part 16 and thus finally to the second external connection 58 (or vice versa).

[0077] Now increases starting from the Fig. 1 If, in the situation shown, the temperature of the device to be monitored by the switch 10 and thus also the temperature of the switch 10 and the switching mechanism 14 used therein exceeds a response temperature of the bimetallic element 28, the bimetallic element 28 snaps out of its Fig. 1 shown low-temperature configuration into its Fig. 2 shown high-temperature configuration. The top side of the bimetallic element 28 snaps from a convex curvature into a concave curvature. The bimetallic element 28 then rests with its outer edge 36 from below, with the insulating film 22 interposed, on the contact carrier element 50. At the same time, the bimetallic element 28 presses the movable contact part 40 downwards with its center 42 and lifts it off the contact surface 46. During this switching movement, the bimetallic element 28 exerts a force that counteracts the force exerted by the spring element 26 on the contact part 40 in the low-temperature position. As a result, the spring element 26 also snaps from its Fig. 1 shown first convex shape on the top into its Fig. 2 shown concave shape on the top.

[0078] This interrupts the current flow through switch 10. Switch 10 is then open.

[0079] Fig. 3 shows a further embodiment of the switch 10 according to the invention. Fig. 3 The second embodiment shown differs from the one shown in Fig. 1 and 2 The first embodiment shown is particularly distinguished by the fact that here the contact surface 46 is arranged directly on the contact carrier element 50, i.e., no separate contact part 48 is attached to the contact carrier element 50. Accordingly, the contact carrier element 50 is designed somewhat flatter here than in the first embodiment. In particular, the central region 54 of the contact carrier element 50 is thus comparatively further spaced from the underside of the cover part 18.

[0080] Fig. 4 shows a third embodiment of the switch 10 according to the invention. The contact carrier element 50 has a spring element 60 therein. This spring element 60 is preferably arranged in the central region 54 of the contact carrier element 50, wherein the contact part 58, on which the contact surface 46 is formed, is arranged on the spring element 60. In principle, however, it is also possible for the contact carrier element 50 to be designed entirely as a spring element 60.

[0081] To better differentiate it from spring element 26, spring element 60 will be referred to as the "second spring element." Spring element 26 will be referred to as the "first spring element."

[0082] The contact carrier element 50 is now designed as a type of counter spring that counteracts the spring element 26 in the low-temperature position of the switching mechanism 14. This allows the contact force with which the movable contact part 40 is pressed against the contact surface 46 in the low-temperature position of the switching mechanism 14 to be increased. This has the advantage of reducing the contact resistance and thus increasing the performance of the switch 10. Furthermore, the second spring element 60 enables further tolerance compensation.

[0083] The spring force exerted by the first spring element 26 is opposite to the spring force exerted by the second spring element 60. The spring force exerted by the second spring element 60 via the contact part 48 onto the movable contact part 40 is preferably greater in magnitude than the spring force exerted by the first spring element 26 onto the contact part 40. However, the second spring element 60 preferably has a shorter spring travel than the first spring element 26.

[0084] Fig. 5 shows a fourth exemplary embodiment of the switch 10 according to the invention. In this embodiment, the contact carrier element 50 is arranged below the switching mechanism 14, i.e., between the switching mechanism 14 and the lower part 16. The contact carrier element 50 is inserted into the lower part 16 and is clamped with its outer edge 52 between the lower part 16 and a spacer ring 62 acting as a hold-down device. The spacer ring 62 can be made of an electrically conductive material or an electrically insulating material. The cover part 18 rests on this spacer ring 62 from above, with the insulating film 22 interposed. Thus, according to this exemplary embodiment, the contact carrier element 50 is also indirectly clamped between the lower part 16 and the cover part 18 and is fixed in its position by the interaction of the lower part 16 and the cover part 18.

[0085] The rear derailleur 14 is compared to the Fig. 1-4 In the embodiments shown, the first spring element 26 is rotated upside down by 180°. In the low-temperature position of the switch 10, the outer edge 30 of the first spring element 26 rests against the underside of the cover part 18 and presses the contact part 40 from above against the contact surface 46 formed on the contact carrier element 50. In this switch position, the outer edge 36 of the bimetallic element 28 hangs freely below.

[0086] In the high temperature position of the Fig. 5 shown switch 10 (high temperature position not shown separately), the bimetallic element 28, however, rests with its outer edge 36 on the spacer ring 62 and thereby lifts the movable contact part 40 from the contact surface 46, so that the switch 10 is open.

[0087] In the fourth embodiment, the contact part 40 is constructed in two parts. Both the spring element 26 and the bimetallic element 28 are held captively by their respective centers 38, 42 on the contact part 40, which is designed as a rivet.

[0088] It is understood that various further modifications of the embodiments shown are possible without departing from the scope of the present invention.

Claims

1. Temperature-dependent switch (10), comprising: - a switch housing (12) with a lower part (16) and a cover part (18) closing the lower part (16); - a contact carrier element (50) which is arranged in the switch housing (12) and has a contact surface (46), wherein at least a portion of the contact carrier element (50) is fixed in position by an interaction of the lower part (16) and the cover part (18);and - a temperature-dependent switching mechanism (14) which is arranged in the switch housing (12) and has a movable contact part (40) which interacts with the contact surface (46) arranged on the contact carrier element (50), wherein the switching mechanism (14) is designed to switch in a temperature-dependent manner between a low-temperature position, in which it presses the movable contact part (40) into contact with the contact surface (46) and thus establishes an electrical connection between a first electrical external terminal (56) of the switch (10) and a second electrical external terminal (58) of the switch (10), and a high-temperature position, in which it keeps the movable contact part (40) spaced from the contact surface (46) and thus interrupts the electrical connection between the first electrical external terminal (56) and the second electrical external terminal (58); 2. Temperature-dependent switch according to claim 1, (i) wherein the switching mechanism (14) is arranged between the contact carrier element (50) and the lower part (16) and the contact carrier element (50) is electrically conductively connected to the cover part (18), or (ii) wherein the switching mechanism (14) is arranged between the contact carrier element (50) and the cover part (18) and the contact carrier element (50) is electrically conductively connected to the lower part (16).

3. Temperature-dependent switch according to claim 1 or 2, wherein the at least one section of the contact carrier element (50) which is fixed in position by the cooperation of the lower part (16) and the cover part (18) has an outer edge (52) of the contact carrier element (50), and wherein a central region (54) of the contact carrier element (50) is spaced from both the lower part (16) and the cover part (18).

4. Temperature-dependent switch according to one of claims 1-3, wherein the contact carrier element (50), in particular an outer edge (52) of the contact carrier element (50), is clamped directly or indirectly between the lower part (16) and the cover part (18).

5. Temperature-dependent switch according to one of claims 1-4, wherein the contact carrier element (50) is designed like a cover and has a thinner wall thickness than the cover part (18).

6. Temperature-dependent switch according to one of claims 1-5, wherein the switching mechanism (14) has a first spring element (26) which, in the low-temperature position of the switching mechanism (14), exerts a first spring force by which the movable contact part (40) is pressed against the contact surface (46).

7. Temperature-dependent switch according to claim 6, wherein the contact carrier element (50) has a second spring element (60) which, in the low-temperature position of the switching mechanism (14), exerts a second spring force by which the contact surface (46) is pressed against the movable contact part (40).

8. A temperature-dependent switch according to claim 7, wherein the first spring force is opposite to the second spring force.

9. Temperature-dependent switch according to claim 8, wherein the second spring force is greater in magnitude than the first spring force.

10. Temperature-dependent switch according to one of claims 7-9, wherein the first spring element (26) has a greater spring travel than the second spring element (60).

11. Temperature-dependent switch according to one of claims 1-10, wherein the switching mechanism (14) comprises a bimetallic element (28).

12. Temperature-dependent switch according to claim 11, wherein the bimetallic element (28) in the high-temperature position of the switching mechanism (14) exerts an opening force on the movable contact part (40) which is opposite to the first spring force and is greater in magnitude than the first spring force.

13. Temperature-dependent switch according to one of claims 1-12, wherein the first external electrical connection (56) is arranged on the outside of the cover part (18) and the second external electrical connection (58) is arranged on the outside of the base part (16).

14. Temperature-dependent switch according to one of claims 1-13, wherein the switch (10) further comprises an insulating film (22) which is arranged between the lower part (16) and the contact carrier element (50).

15. Temperature-dependent switch according to one of claims 1-14, wherein the lower part (16) has a free, upper edge (20) which is flanged or bent over onto the cover part (18).

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