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

Abstract

Temperature-dependent switching mechanism (10) for a temperature-dependent switch (100), comprising: a bimetallic element (12); a spring element (14); an electrically conductive contact part (16) formed on or attached to the spring element (14); and at least one retaining claw (18) formed on or attached to the spring element (14), wherein the at least one retaining claw (18) has a support surface (34); wherein the bimetallic element (12) is configured to snap from a low-temperature configuration to a high-temperature configuration when a response temperature is exceeded, and wherein the bimetallic element (12) is supported on the support surface (34) in its high-temperature configuration.

Description

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

[0002] Temperature-dependent switching devices and switches with such temperature-dependent switching devices are already known in principle. Examples of temperature-dependent switching devices and switches are known from DE 10 2011 119 632 B3, DE 10 2022 118 405 B3, and DE 10 2013 017 232 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 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 element to which a movable contact part is attached, as well as a bimetallic element placed over the movable contact part. The spring element 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 element, designed as a spring snap-action disc, 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 disc and the movable contact part into the stationary counter-contact and from there into the cover part.

[0006] 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 2011 119 632 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.

[0007] 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.

[0008] If the temperature of the bimetallic element rises above its response temperature due to a temperature increase in the device to be protected, the 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.

[0009] 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.

[0010] 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.

[0011] In many temperature-dependent switches, the bimetallic element is therefore preferably inserted into the switch housing as a loose individual part during manufacture. The bimetallic element, for example, is slipped over the contact part attached to the spring element using a central through-hole provided therein. Only when the switch housing is closed is the bimetallic element 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 element is inserted individually, has proven to be relatively cumbersome, as several steps are necessary to insert the switch into the switch housing. Such switches are therefore usually difficult to manufacture using automated processes.

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

[0013] The switch mechanism, consisting of the bimetallic element, the spring element, 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 inserted into the switch housing as a captive unit in a single step. This simplifies switch production considerably.

[0014] In the switch known from DE 10 2011 119 632 B3, the spring element 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 prefabricated switchgear as a semi-finished product, the welded or soldered connection between the contact part and the spring element can break. Such defective switches can then, of course, no longer be used. A particular problem is that such a defect can only be detected after the switch has been assembled, since only then is a functional test of the switchgear possible.

[0015] The latter points in particular have been improved in the derailleur known from DE 10 2022 118 405 B3. The derailleur known from this document has an additional derailleur housing in which the derailleur unit, which comprises the bimetallic element, the spring element, and the contact part, is held captive but with play. This additional derailleur housing not only enables the pre-production of the derailleur as a semi-finished product, but also protects the fragile components of the derailleur from damage, particularly during storage. Furthermore, it simplifies the installation of the derailleur in a switch. A further advantage of the additional derailleur housing is that a functional test of the derailleur can be carried out before it is installed in the switch, since the snap-action behavior of the bimetallic element can be tested in the derailleur housing.

[0016] A similarly advantageous solution is known from DE 10 2013 017 232 A1. The temperature-dependent switching mechanism known from this publication has a ring-shaped frame in which the bimetallic element and the spring element are held captively. This design also protects the fragile components of the switching mechanism during storage. Furthermore, it also allows for a functional test of the switching mechanism before it is installed in the switch or switch housing.

[0017] Although the latter two solutions in particular have proven advantageous, there is still room for further improvements. In particular, the manufacturability of the rear derailleur can be improved and its size further reduced. Further simplifications and improvements are also expected to achieve further cost savings.

[0018] It is therefore an object of the present invention to provide a temperature-dependent switching mechanism in which, in particular, the aforementioned points are further improved. In particular, it is an object to provide a temperature-dependent switching mechanism that can be pre-produced as a semi-finished product and stored in bulk without being susceptible to damage that could lead to a defect in the switching mechanism. The switching mechanism pre-produced as a semi-finished product should nevertheless be as easy to use as possible in a temperature-dependent switch and enable its production with as few work steps as possible. Furthermore, a functional test of the switching mechanism should be possible even before it is installed in the switch.

[0019] This object is achieved according to the invention by a temperature-dependent switching device with: a bimetallic element; a spring element; an electrically conductive contact part formed on the spring element or fastened to the spring element; and at least one retaining claw formed on the spring element or fastened to the spring element, wherein the at least one retaining claw has a support surface; wherein the bimetallic element is configured to snap from a low-temperature configuration to a high-temperature configuration when a response temperature is exceeded, and wherein the bimetallic element is supported on the support surface in its high-temperature configuration.

[0020] The switching mechanism according to the invention thus has one or more retaining claws formed on or attached to the spring element and serving to hold the bimetallic element. The at least one retaining claw serves not only to hold the bimetallic element to prevent it from detaching from the switching mechanism, but also to protect the bimetallic element during bulk storage of the switching mechanism.

[0021] A support surface is provided on the at least one retaining claw, against which the bimetallic element rests in its high-temperature configuration. This has the advantage that a functional test can be performed with the switching mechanism according to the invention even before its installation in a switch. The bimetallic element can assume both of its positions / configurations (low-temperature configuration and high-temperature configuration) within the switching mechanism without the need for additional components.

[0022] Compared to the prior art derailleurs mentioned above, the derailleur according to the invention is significantly more compact and simpler, in particular, it consists of fewer components. Due to the provision of at least one retaining claw, a derailleur housing, as proposed in DE 10 2022 118 405 B3, is no longer necessary. Since the at least one retaining claw is formed on the spring element according to the invention, i.e., for example, is designed integrally with the spring element or is attached to the spring element, the derailleur according to the invention is thus also significantly smaller and more compact than the derailleur known from DE 10 2022 118 405 B3.

[0023] An annular frame, as proposed in DE 10 2013 017 232 A1, is also no longer necessary according to the invention. Instead, at least one retaining claw is used in the switching mechanism according to the invention. Due to the support surface arranged thereon, the bimetallic element can be supported directly on the retaining claw in its high-temperature configuration, which is also advantageous in contrast to the switching mechanism known from DE 10 2013 017 232 A1, where the bimetallic element in its high-temperature configuration is supported directly on the spring element. This relieves the spring element, in particular, which increases the durability of the switching mechanism overall.

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

[0025] According to one embodiment, the bimetallic element, the spring element and the contact part form a switching unit that is held together in a captive manner.

[0026] The individual parts of the switchgear unit can no longer become accidentally detached from one another. This has the advantage that the switchgear can be pre-produced as a semi-finished product and can be stored more easily and reliably than in bulk or on a production line. Furthermore, the switchgear, with all its individual components, can be installed as a complete unit in a switch housing, simplifying switch assembly and thus making it easier to automate.

[0027] According to a further embodiment, the bimetallic element is held captively on the contact part and / or is held captively on the spring element by the at least one holding claw.

[0028] This prevents the loss of the bimetallic element, especially during belt or bulk material storage. It also ensures that the bimetallic element detaches from the switching mechanism when the switching mechanism is installed in a switch and in use. The most mechanically stable and secure way of mounting the bimetallic element is achieved when it is held captively both at the contact part and at least at the spring element by at least one retaining claw.

[0029] According to a further embodiment, the at least one retaining claw protrudes on one side from a first side of the spring element, which side faces the bimetal element.

[0030] In other words, the at least one retaining claw protrudes from the spring element on the same side as the bimetallic element. Protruding the at least one retaining claw on one side has the advantage of a space-saving design for the switching mechanism.

[0031] In the case of several retaining claws, these preferably all protrude from the same (first) side of the spring element on one side.

[0032] According to a further embodiment, the at least one retaining claw protrudes in a first direction from the first side of the spring element, wherein the support surface is oriented transversely to the first direction and faces the spring element.

[0033] The term "transverse" does not necessarily refer to an orthogonal or vertical alignment. Instead, it refers to any type of alignment that is not parallel. Thus, an oblique alignment at an angle other than 0° also falls under the term "transverse."

[0034] According to the aforementioned embodiment, the at least one retaining claw preferably has a first section that protrudes from the spring element and extends in the first direction, as well as a second section that is connected to the first section, runs transversely thereto, and on which the support surface is arranged such that it faces the spring element. Particularly preferably, the at least one retaining claw has the cross-sectional shape of an inverted (upside down) L.

[0035] According to a further embodiment, the at least one retaining claw has at least two retaining claws.

[0036] According to this embodiment, the at least two retaining claws are preferably arranged at a distance from one another on the spring element. Particularly preferably, the at least two retaining claws according to this embodiment are each at the same distance from a central axis of the spring element. In the case of three or more retaining claws, these are preferably arranged evenly distributed on the spring element, resulting in rotational symmetry around the central axis.

[0037] The design of several individual retaining claws can usually be manufactured more easily and cost-effectively than a comparatively large, continuous retaining claw that extends, for example, along the entire circumference or along a large part of the circumference of the bimetallic element (i.e. more than 50% of the circumference of the bimetallic element).

[0038] According to a further embodiment, the at least one retaining claw is integrally connected to the spring element or is materially fastened to the spring element.

[0039] The at least one retaining claw can, for example, be designed as a single piece with the spring element. Alternatively, the at least one retaining claw is preferably welded or soldered to the spring element. This creates a mechanically very stable retaining claw that is inseparably connected to the spring element.

[0040] According to a further embodiment, the spring element has an outer edge, wherein the at least one retaining claw is spaced from the outer edge.

[0041] The outer edge is preferably a circumferentially extending outer edge from which the at least one retaining claw is spaced. Particularly preferably, the at least one retaining claw is spaced closer to a central axis of the spring element than the outer edge of the spring element. In other words, the at least one retaining claw is preferably offset radially inward relative to the outer edge of the spring element, which may, for example, be disk-shaped, in particular circular disk-shaped.

[0042] This has the advantage that the switching mechanism according to the invention can be very easily fixed in the switch housing during assembly of a switch, since the outer edge of the spring element can be clamped between two parts of the switch housing to secure the switching mechanism. The function of the at least one retaining claw is not impaired.

[0043] According to a further embodiment, the outer edge lies in a plane and a radially inner region of the spring element is curved.

[0044] This further simplifies the fixation of the switching mechanism within the switch housing. Furthermore, the curved inner area of ​​the spring element allows sufficient freedom of movement for the spring element, allowing it to move together with the bimetallic element during switching operations.

[0045] According to a further embodiment, the spring element has a first configuration when the bimetallic element is in its low-temperature configuration, wherein the spring element is brought into a second configuration by the bimetallic element when the bimetallic element snaps into its high-temperature configuration.

[0046] The spring element is preferably a spring snap-action disc, which, similar to the bimetallic element, has two different configurations or positions. Particularly preferably, the two configurations / positions of the spring element are mechanically stable configurations / positions. However, unlike the two configurations of the bimetallic element, the two configurations / positions of the spring element are temperature-independent.

[0047] According to a further embodiment, the spring element together with the at least one retaining claw forms an open housing in which the bimetallic element is arranged but is accessible from the outside, wherein this open housing at least partially surrounds the bimetallic element from a first side, a second side opposite the first side and a circumferential side running between and transversely to the first and the second side.

[0048] The bimetallic element is thus encapsulated in a manner of speaking within the housing formed by the spring element and at least one retaining claw. This provides good protection for the bimetallic element, which is particularly advantageous when the switchgear is stored in bulk. This type of "housing" preferably surrounds the bimetallic element at least partially on all sides, while the bimetallic element remains accessible from the outside, which is of immense importance for the function of the switchgear.

[0049] According to a further embodiment, the open housing formed by the spring element together with the at least one retaining claw has an opening on the second side, the inner diameter of which is smaller than an outer diameter of the bimetallic element measured parallel thereto.

[0050] This ensures in a simple way that the bimetallic element cannot be released from at least one of the retaining claws. This ensures that the bimetallic element is held captively to the spring element.

[0051] According to a further embodiment, the rear derailleur is designed to be rotationally symmetrical about a central axis.

[0052] This also simplifies the installation of the derailleur, as it can be inserted into the switch housing in any orientation relative to its central axis. Furthermore, the symmetrical alignment of the derailleur ensures optimal force distribution when the switch is closed.

[0053] According to a further embodiment, the bimetallic element has an opening through which the contact part protrudes. The bimetallic element is preferably disc-shaped. Said opening is preferably formed centrally in the bimetallic element, with the bimetallic element being placed over the contact part with this opening.

[0054] According to a further embodiment, the spring element preferably comprises an electrically conductive material.

[0055] This has the advantage that the spring element can be used as an electrically conductive component, so that current flows through the spring element when the switch is closed. This eliminates the need for current to flow through the bimetallic element when the switch is closed, thus reducing the load on the bimetallic element and extending its service life.

[0056] As already mentioned at the beginning, the present invention relates not only to the temperature-dependent switching mechanism, but also to a temperature-dependent switch in which the switching mechanism according to the invention is used. It is understood that the above-mentioned embodiments and the features defined in the dependent claims relate not only to the switching mechanism according to the invention, but also to the switch according to the invention.

[0057] According to one embodiment of the temperature-dependent switch, it comprises a switch housing in which the temperature-dependent switching mechanism is arranged and which has a lower part and a cover part, with the spring element clamped between the lower part and the cover part. Preferably, the outer edge of the spring element is clamped between the lower part and the cover part of the switch housing. The switch is thus relatively easy to install and has a mechanically stable construction.

[0058] 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.

[0059] Embodiments of the invention are illustrated in the drawings and explained in more detail in the following description. Fig. 1 is a schematic sectional view of the temperature-dependent switching mechanism according to a first embodiment of the present invention, wherein the switching mechanism is in a first switching position; Fig. 2 is a schematic sectional view of the Fig. 1 shown temperature-dependent switching mechanism, wherein the switching mechanism is in a second switching position; Fig. 3 is a schematic sectional view of the temperature-dependent switching mechanism according to a second exemplary embodiment of the present invention, wherein the switching mechanism is in its first switching position; Fig. 4 is a schematic plan view from above of a spring element which can be used in the temperature-dependent switching mechanism according to the invention; Fig. 5 is a schematic sectional view of the temperature-dependent switch according to an exemplary embodiment of the present invention, wherein the switch is in its low-temperature position; Fig. 6 is a schematic sectional view of the Fig. 5 shown temperature-dependent switch, wherein the switch is in its high-temperature position; Fig. 7 is a schematic sectional view of the temperature-dependent switch according to a further embodiment of the present invention, wherein the switch is in its low-temperature position; and Fig. 8 is a schematic sectional view of the Fig. 7 shown temperature-dependent switch, with the switch in its high-temperature position.

[0060] Fig. 1 und 2 show a first embodiment of the switching mechanism according to the invention in a schematic sectional view. Fig. 1 shows the low temperature position of the switchgear. Fig. 2 shows the high-temperature position of the switching mechanism. The switching mechanism is designated in its entirety by reference number 10.

[0061] The switching mechanism 10 is a temperature-dependent switching mechanism. The switching mechanism 10 is constructed in several parts. It comprises a bimetallic element 12, a spring element 14, an electrically conductive contact part 16, and at least one retaining claw 18.

[0062] The bimetallic element 12, as the name suggests, comprises a bimetallic element. The spring element 14 and the contact part 16 are made of an electrically conductive material, preferably metal. The at least one retaining claw 18 is preferably also made of metal. However, the at least one retaining claw 18 does not necessarily have to be made of an electrically conductive material; it can also be made of an electrically non-conductive material.

[0063] The one in Fig. 1 und 2 In the embodiment shown, the bimetallic element 12 is essentially circular disk-shaped. The bimetallic element 12 is therefore also referred to as a bimetallic disc. Due to its physical properties, the bimetallic element 12 is sometimes also referred to as a bimetallic snap-action disc.

[0064] In the embodiment shown here, the bimetal element 12 has a central opening 20 with which the bimetal element 12 is placed over the contact part 16. In the embodiment shown in Fig. 1 und 2 In the embodiment shown, the bimetallic element 12 is placed with its opening 20 over the contact part 16 without being firmly connected to the contact part 16. In other words, the bimetallic element 12 and contact part 16 are loosely coupled to one another at this point and movable relative to one another.

[0065] The contact part 16 is fastened to the spring element 14 in the present embodiment. More precisely, the contact part 16 is integrally connected to the spring element 14 in this embodiment. The contact part 16 is, for example, soldered or welded to the spring element 14. For better centering, the contact part 16 has an extension 22 at its end, with which it is inserted into an opening 24 provided centrally in the spring element 14. Approximately in the middle, the contact part 16 has a collar 26, with the underside of which the contact part 16 rests flat on the top side of the spring element 14. The integral connection between the spring element 14 and the contact part 16 is preferably provided on the underside of the collar 26. The collar 26 formed on the contact part 16 also serves, as will be explained in more detail below, to support the bimetallic element 12 in its high-temperature configuration (see Fig. 2 ).

[0066] It should be noted at this point that, instead of a material connection, the contact part 16 can also be integrally connected to the spring element 14. In other words, the spring element 14 and the contact part 16 can be designed as a single piece. In such a case, the contact part 16 is preferably designed as a raised portion that protrudes from the top side of the spring element 14.

[0067] The at least one retaining claw 18 is arranged in the region of the outer edge 28 on the spring element 14. In the Fig. 1 und 2 In the embodiment shown, the at least one retaining claw is fastened to the spring element 14 in a materially bonded manner, for example by welding or soldering.

[0068] The at least one retaining claw 18 protrudes upwardly on one side from the upper side 30 of the spring element 14, which is also referred to herein as the first side 30 of the spring element 14. This first side 30 of the spring element 14 is the side of the spring element 14 that faces the bimetallic element 12.

[0069] More precisely, the at least one holding claw 18 is in a first direction 32, which is Fig. 1 und 2 the vertical direction, from the first side 30 of the spring element 14. On the inside of the at least one retaining claw 18, a support surface 34 is provided. This support surface 34 runs transversely, preferably perpendicularly to the first direction 32. The bimetallic element 12 is supported on this support surface 34 with its outer edge 36 in its high-temperature position, as will be explained in more detail below (see Fig. 2 ).

[0070] The spring element, together with the at least one retaining claw 18, forms a partially open housing in which the bimetallic element 12 is arranged and held captively, but is accessible from the outside. This open housing, formed by the spring element 14 and the at least one retaining claw 18, at least partially surrounds a first side 38 of the bimetallic element 12, which faces the first side 30 of the spring element 14, as well as an opposite second side 40 of the bimetallic element 12 and a bimetallic element circumferential side 42 running transversely to the first and second bimetallic element sides 38, 40. The open housing formed by the spring element 14 together with the at least one retaining claw 18 has an opening 44 on a side facing the second side 40 of the bimetallic element 12, through which opening the movable contact part 16 is accessible from the outside.

[0071] The inner diameter of this opening 44 is smaller than an outer diameter of the bimetallic element 12, measured parallel thereto. This ensures that the bimetallic element 12 is held captively on the spring element 14 by the at least one retaining claw 18. The bimetallic element 12, the spring element 14, and the contact part 16 thus form a switching unit that is held together captively.

[0072] In the Fig. 1 In the low-temperature position of the switching mechanism 10 shown, the bimetallic element 12 is convexly curved on its second side 40 (top side of the bimetallic element 12). Likewise, a radially inner region 46 of the spring element 14 is convexly curved on its first side 30 (top side of the spring element 14) in the Fig. 1 shown low-temperature position is convexly curved. In other words, in the low-temperature position of the switching mechanism 10, both the bimetallic element 12 and the radially inner region 46 of the spring element 14 are curved upwards (see Fig. 1 In this switching position, the bimetallic element 12 rests loosely from above on the collar 26 of the contact part 16. The free outer edge 36 of the bimetallic element 12 is mounted in a virtually force-free manner and preferably has no contact with the spring element 14 and / or the at least one retaining claw 18.

[0073] If, starting from this switching position of the switching mechanism 10, the temperature of the switching mechanism 10 increases beyond a response temperature of the bimetallic element 12, the bimetallic element 12 snaps out of its Fig. 1 shown low temperature position to its Fig. 2 shown high-temperature position. The second side 40 of the bimetal element 12 (top side of the bimetal element 12) is now concavely curved. The bimetal element 12 is supported with its outer edge 36 on the support surface 34, which is arranged on the at least one retaining claw 18. At the same time, the bimetal element 12 presses the contact part 16 in the direction of the spring element 14 with its inner edge 48. In other words, both the bimetal element 12 and the spring element 14 bulge downwards, so that not only the bimetal element 12 is now concavely curved on its second side 40 (top side), but also the spring element 14 is now concavely curved on its first side 30 (top side).

[0074] Since the at least one retaining claw 18 acts as a type of abutment in the high-temperature position of the switching mechanism 10, against which the bimetallic element 12 can be supported, and the switching mechanism 10 together with its components 12, 14, 16, 18 forms a captively held together switching mechanism unit even in the low-temperature position, a functional test of the switching mechanism 10 can be carried out without additional components, in particular without the need to install the switching mechanism 10 in a temperature-dependent switch. Fig. 1 und 2 The rear derailleur 10 shown thus forms a separately functional, storable semi-finished product.

[0075] Fig. 3 shows a second embodiment of the switching mechanism 10 according to the invention in a schematic sectional view. The basic structure and the functioning of the switching mechanism 10 do not differ from that shown in Fig. 1 und 2 The basic structural design of the switching mechanism 10 is also at least similar to that in the first embodiment. However, one difference is that the at least one retaining claw 18 is integrally connected to the spring element 14 or is formed in one piece with it. Preferably, the spring element 14, as well as the at least one retaining claw 18, is formed from a thin metal sheet.

[0076] Another difference of this in Fig. 3 The advantage of the second embodiment shown is that the contact part 16 is designed as a type of rivet, which is connected to both the bimetallic element 12 and the spring element 14. In the Fig. 3 In the second embodiment shown, the bimetallic element is thus not only held captively on the spring element by the at least one retaining claw 18, but also captively on the contact part 16. A support ring 50 can be arranged between the bimetallic element 12 and the spring element 14 on the contact part 16, which is designed as a rivet. However, the latter is not absolutely necessary.

[0077] Fig. 4 shows the spring element 14 of the Fig. 3 shown embodiment of the switching mechanism 10 in a plan view from above. As can be seen therefrom, the spring element 14 is essentially circular disk-shaped, with various recesses 52 being provided in order to reduce the electrical resistance and save material. Instead of a (single) retaining claw 18 that completely encircles the circumference, three retaining claws 18 are provided here, which are distributed and arranged at a distance from one another. More precisely, the three retaining claws are regularly distributed over the circumference of the spring element 14. It is understood that, in principle, two or more than three retaining claws 18 can also be provided. Likewise, just a single retaining claw 18 can serve as an abutment for the bimetallic element 12, provided that this at least one retaining claw 18 extends over a larger part of the circumference of the spring element 14.

[0078] The at least one retaining claw 18 is preferably arranged at a distance from the outer edge 28 of the spring element 14. Adjacent to this outer edge 28, the spring element 14 preferably has a peripherally surrounding edge region 58, which lies in one plane, i.e. is flat or even. The radially inner region 46 of the spring element 14, which in the Fig. 4 shown embodiment is formed by three radially extending webs 54 and a central region 56, is curved.

[0079] The flat or planar outer edge region 58 of the spring element 14 offers, as will be explained in more detail below, the advantage of the simplest possible attachment and fixing within a temperature-dependent switch.

[0080] The spring element 14 is designed to be rotationally symmetrical about a central axis 60. Likewise, the entire switching mechanism 10 is preferably designed to be rotationally symmetrical about the central axis 60. Accordingly, the switching mechanism 10 can be inserted into a switch housing of a switch in any position rotated about the central axis 60. This greatly simplifies the assembly of the switching mechanism 10.

[0081] Fig. 5 and 6 show a first embodiment of a temperature-dependent switch in which the switching mechanism 10 according to the invention is used. Fig. 5 shows the low temperature position of the switch. Fig. 6 shows the high-temperature position of the switch. The switch is designated in its entirety by reference numeral 100. The switch 100 has a switch housing 62, which functions as an outer housing for the switching mechanism 10. The switch housing 62 comprises a pot-shaped lower part 64 and a cover part 66, which is held to the lower part 64 by a bent or flanged upper edge of the lower part 64.

[0082] Both the lower part 64 and the cover part 66 are in the Fig. 5 and 6In the embodiment shown, the housing is made of an electrically conductive material, preferably metal. An insulating film 68 is arranged between the lower part 64 and the cover part 66. The insulating film 68 provides electrical insulation between the lower part 64 and the cover part 66. Likewise, the insulating film 68 provides a mechanical seal that prevents liquids or contaminants from entering the housing interior from the outside.

[0083] Since the lower part 64 and the cover part 66 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 can also simultaneously serve as the electrical connection of the switch 100. For example, the outer surface 65 of the lower part 64 can function as the first electrical connection, and the outer surface 67 of the cover part 66 can function as the second electrical connection of the switch 100.

[0084] The derailleur 10 is clamped between the lower part 64 and the cover part 66. More precisely, the derailleur 10 is clamped between a spacer ring 70 and the cover part 66. For this purpose, the outer edge region 58 of the spring element 14 rests on the spacer ring 70 and is clamped from the opposite side by the cover part 66.

[0085] Furthermore, the switching mechanism 10 rests with its at least one retaining claw 18 against the inner circumference of the spacer ring 70. The spacer ring 70 thus allows both the fixing and centering of the switching mechanism 10. This aligns the movable contact part 16 of the switching mechanism 10 relative to a stationary mating contact 72, which is arranged on the inside of the lower part 64 of the switch housing 62. This mating contact 72 is also referred to herein as a stationary contact.

[0086] In the Fig. 5 In the low-temperature position of the switch 100 shown, which is also referred to as the closed position of the switch 100, the switching mechanism 10 establishes an electrically conductive connection between the lower part 64 and the cover part 66 and thus between the two external connection surfaces 65, 67 of the switch 100. The electrically conductive contact between the two external connection surfaces 65, 67 of the switch 100 is established in particular via the spring element 14 and the movable contact part 16, which interacts with the stationary contact 72. The contact pressure between the movable contact part 16 and the stationary contact 72 is generated by the spring element 14. In this state, the bimetallic element 12 is mounted in the switching mechanism 10 with almost no force.

[0087] If the temperature of the device to be protected and thus the temperature of the switch 100 increases to the switching temperature of the bimetal element 12 or above the switching temperature, the bimetal element 12 snaps from its Fig. 5 shown low temperature position to its Fig. 6 shown high-temperature position. During this snapping action, the bimetallic element 12 rests with its outer edge 36 on the support surface 34 provided on the at least one retaining claw 18, and presses the movable contact part 16 together with the spring element 14 upwards with its inner edge 48. As a result, the spring element 14 simultaneously bends upwards with its center, lifting the movable contact part 16 from the stationary contact 72. The circuit is thereby interrupted, and the switch 100 is thus opened.

[0088] When the device to be protected and thus the switch 100 together with the bimetal element 12 cool down again, the bimetal element 12 snaps back into its low-temperature position when a return temperature is reached, which is also referred to as the return temperature, as is the case, for example, in Fig. 5 This allows for reversible switching behavior.

[0089] Of course, it is also possible for a corresponding locking device to prevent the switch 100 from switching back to the high-temperature position after it has snapped into place. Such locking devices, which are used particularly in one-shot switches where switching back to the high-temperature position is to be prevented, are already known in numerous prior art designs.

[0090] Fig. 7 and 8show a further embodiment of the switch 100 according to the invention, again in a schematic sectional view both in the low-temperature position ( Fig. 7 ) as well as in the high temperature position ( Fig. 8 ) of switch 100.

[0091] The 70' spacer ring has a slightly different shape. A significant difference to the one in Fig. 5 and 6 However, the advantage of the embodiment shown is that the counter contact 72 is not designed as a stationary contact, but is arranged on a counter spring element 74. This counter spring element 74 allows for optimal compensation of manufacturing tolerances. Furthermore, the contact pressure in the closed state of the switch (see Fig. 7 ) because the counter spring element 74 counteracts the spring element 14 and thus increases the force with which the two contacts 16, 72 are pressed against each other. However, the switching principle otherwise remains the same, as previously explained with reference to the Fig. 5 and 6 shown embodiment was described.

[0092] It is understood that various further modifications can be made both to the switching mechanism 10 itself and to the switch housing 62 without departing from the scope of the present invention. In particular, the shape of the at least one retaining claw shown here can be varied almost arbitrarily, which is why the term "retaining claw" is to be interpreted broadly in this context. Functionally, the at least one retaining claw 18 serves as a holder for the bimetallic element 12, against which the bimetallic element can rest with its edge 36, particularly in the high-temperature position of the switching mechanism 10.

Claims

1. Temperature-dependent switching mechanism (10) for a temperature-dependent switch (100), comprising: - a bimetallic element (12); - a spring element (14); - an electrically conductive contact part (16) which is formed on the spring element (14) or fastened to the spring element (14); and - at least one retaining claw (18) which is formed on the spring element (14) or fastened to the spring element (14), wherein the at least one retaining claw (18) has a support surface (34); wherein the bimetallic element (12) is configured to snap over from a low-temperature configuration to a high-temperature configuration when a response temperature is exceeded, and wherein the bimetallic element (12) is supported on the support surface (34) in its high-temperature configuration.

2. Temperature-dependent switching mechanism (10) according to claim 1, wherein the bimetallic element (12), the spring element (14) and the contact part (16) form a switching mechanism unit held together in a captive manner.

3. Temperature-dependent switching mechanism (10) according to claim 1 or 2, wherein the bimetallic element (12) is held captively on the contact part (16) and / or is held captively on the spring element (14) by the at least one holding claw (18).

4. Temperature-dependent switching mechanism (10) according to one of claims 1-3, wherein the at least one retaining claw (18) protrudes on one side from a first side (30) of the spring element (14) which faces the bimetallic element (12).

5. Temperature-dependent switching mechanism (10) according to claim 4, wherein the at least one retaining claw (18) protrudes in a first direction (32) from the first side (30) of the spring element (14), and wherein the support surface (34) is oriented transversely to the first direction (32) and faces the spring element (14).

6. Temperature-dependent switching mechanism (10) according to one of claims 1-5, wherein the at least one retaining claw (18) has a single retaining claw (18) which extends at least over a large part of the circumference of the spring element (14), or at least two retaining claws (18).

7. Temperature-dependent switching mechanism (10) according to one of claims 1-6, wherein the at least one retaining claw (18) is integrally connected to the spring element (14) or is materially fastened to the spring element (14).

8. Temperature-dependent switching mechanism (10) according to one of claims 1-7, wherein the spring element (14) has an outer edge (28) and the at least one retaining claw (18) is spaced from the outer edge (28).

9. Temperature-dependent switching mechanism (10) according to claim 8, wherein the outer edge (28) lies in a plane and a radially inner region (46) of the spring element (14) is curved.

10. Temperature-dependent switching mechanism (10) according to one of claims 1-9, wherein the spring element (14) has a first configuration when the bimetallic element (12) is in its low-temperature configuration, and wherein the spring element (14) is brought into a second configuration by the bimetallic element (12) when the bimetallic element (12) snaps into its high-temperature configuration.

11. Temperature-dependent switching mechanism (10) according to one of claims 1-10, wherein the spring element (14) together with the at least one retaining claw (18) forms an open housing in which the bimetallic element (12) is arranged, but is accessible from the outside, wherein this open housing at least partially surrounds the bimetallic element (12) from a first side (38), a second side opposite the first side (38) and a circumferential side (42) running between and transversely to the first and the second side (38, 40).

12. Temperature-dependent switching mechanism (10) according to claim 11, wherein the open housing formed by the spring element (14) together with the at least one retaining claw (18) has an opening (44) on the second side (40), the inner diameter of which is smaller than an outer diameter of the bimetallic element (12) measured parallel thereto.

13. Temperature-dependent switching mechanism (10) according to one of claims 1-12, wherein the switching mechanism (10) is designed to be rotationally symmetrical about a central axis (60), and wherein the bimetallic element (12) has a central opening through which the contact part (16) projects.

14. Temperature-dependent switch (100) with a temperature-dependent switching mechanism according to one of claims 1-13.

15. Temperature-dependent switch (100) according to claim 14, wherein the switch (100) has a switch housing (62) in which the temperature-dependent switching mechanism (10) is arranged and which has a lower part (64) and a cover part, wherein the spring element (14) is clamped between the lower part (64) and the cover part (66).

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