Temperature-dependent switching device and temperature-dependent switch

Abstract

Temperature-dependent switching mechanism (12) for a temperature-dependent switch (10), comprising a temperature-dependent bimetallic disc (18), a temperature-independent spring disc (20), an electrically conductive contact part (22) on which the bimetallic disc (18) and the spring disc (20) are held captive, and a retaining ring (24) which has a base body (34) made of electrically conductive material and surrounds a circumferential edge (32) of the spring disc (20) and thereby holds the spring disc (20) captive.

Description

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

[0002] Temperature-dependent switches are already known in many forms. An example of a temperature-dependent switch is disclosed in DE 10 2013 102 089 A1.

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

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

[0005] In the switch known from DE 10 2013 102 089 A1, the switching mechanism is located inside the switch housing. The switch housing has a two-part construction. It comprises a lower part made of electrically conductive material (e.g., metal), which is rigidly connected to a cover part, also made of electrically conductive material (e.g., metal), with an insulating film in between. The temperature-dependent switching mechanism located inside the switch housing includes a spring washer to which a movable contact element is attached, and a bimetallic disc placed over the movable contact element. The spring washer presses the movable contact element against a stationary mating contact located on the inside of the switch housing on the cover element.The spring disc rests against the lower part of the switch housing with its outer edge, so that the electric current flows from the lower part through the spring 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 switch is primarily due to the temperature-dependent bimetallic disc. This disc is usually designed as a multi-layered, active, sheet-like component consisting of two, three, or four interconnected components with different coefficients of thermal expansion. The bonding of the individual layers of metals or metal alloys in such bimetallic discs is usually material-bonded or form-fitted and is achieved, for example, by rolling.

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

[0008] If the temperature of the bimetallic disc rises above its response temperature due to a temperature increase in the device being protected, the disc snaps from its low-temperature configuration to its high-temperature configuration. In this process, the bimetallic disc works against the spring disc in such a way that it lifts the moving contact part from the stationary counterpart contact, thus opening the switch and shutting down the device being protected, preventing it from heating up further.

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

[0010] In the switch known from DE 10 2013 102 089 A1, the bimetallic disc in its low-temperature configuration is mechanically force-free mounted in the switch housing, and the bimetallic disc is not used to conduct the current. This has the advantage that the bimetallic disc has a longer service life, and that the switching point, i.e., the response temperature of the bimetallic disc, does not change even after many switching cycles.

[0011] In many temperature-dependent switches, the bimetallic disc is therefore preferably inserted into the switch housing as a loose component during manufacturing. The bimetallic disc, for example, is fitted over the contact part attached to the spring washer, using a central through-hole provided in the disc. Only when the switch housing is closed is the bimetallic disc fixed in its position and its position relative to the other components of the switching mechanism determined. However, producing such a switch, in which the bimetallic disc is inserted separately, has proven cumbersome, as several steps are necessary to insert the switching mechanism into the switch housing.

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

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

[0014] In the switch known from DE 10 2011 119 632 B3, the spring washer is welded or soldered to the contact part to ensure the best possible electrical contact between the two components. However, it has been observed that, particularly when handling bulk materials, the prefabricated switchgear can break the welded or soldered connection between the contact part and the spring washer. Such defective switches can then no longer be used. A particular problem is that such a defect can only be detected after the switch has been assembled, as a functional test of the switchgear is only possible at that point.

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

[0016] Another method for pre-producing the switching mechanism as a semi-finished product is known from DE 29 17 482 A1 and DE 10 2007 014 237 A1. The captive unit of the switching mechanism is achieved by connecting the bimetallic disc and the spring disc with a rivet. Depending on the switch design, this rivet can also form the movable contact part of the switching mechanism. The rivet has a two-part construction and features a rivet pin that interacts with a hollow rivet or a rivet pin with an attached counter-holder. While this type of rivet connection between the spring disc and the bimetallic disc has proven to be a mechanically durable connection over the long term, it also has other disadvantages. For example, the bimetallic disc is usually fixed to the rivet, which can lead to deformation and thus malfunctions of the bimetallic disc.In summary, it is therefore also possible in principle to store the switching mechanism in bulk. However, damage to the switching mechanism during bulk storage cannot be ruled out here either. DE 10 2013 017232 A1 discloses another known temperature-dependent switching mechanism according to the preamble of claim 1.

[0017] It is therefore an object of the present invention to provide a temperature-dependent switching mechanism that can be pre-produced as a semi-finished product and stored in bulk without being susceptible to damage that would lead to a defect in the switching mechanism. The switching mechanism, which can be pre-produced as a semi-finished product, should also be as easy as possible to use in a temperature-dependent switch and enable its manufacture with as few work steps as possible. Furthermore, the electrical contact between the switching mechanism and the external terminals of the switch should be improved.

[0018] This problem is solved according to the invention by a temperature-dependent switching mechanism for a temperature-dependent switch according to the features of claim 1.

[0019] According to the invention, the switching mechanism comprises an additional retaining ring which, acting as a kind of switching mechanism housing, circumferentially surrounds the spring disc and holds it securely in place. Since the spring disc and the bimetallic disc are also securely held to the electrically conductive contact part, the aforementioned components of the switching mechanism—i.e., the bimetallic disc, the spring disc, and the contact part—are all securely (directly or indirectly) held to the retaining ring. The switching mechanism can therefore be prefabricated as a secure, captive unit and is suitable for bulk material storage.

[0020] Since the retaining ring surrounds the circumferential edge of the spring washer and holds it securely in place, it protects the exposed, circumferential edge of the spring washer. This is particularly advantageous during bulk material storage of the switchgear.

[0021] Since the retaining ring is also made of electrically conductive material (e.g., metal), it can further simplify the electrical contacting of the switching mechanism. The retaining ring itself can, in fact, function as an electrical contact.

[0022] During manufacturing, the temperature-dependent switching mechanism simply needs to be inserted into a switch housing and the retaining ring brought into electrical contact with one of the two external terminals of the switch. In the simplest case, this can be achieved by surface contact, in which the switching mechanism according to the invention, with the retaining ring, is placed onto a contact surface arranged in the switch housing.

[0023] In the manufacture of a temperature-dependent switch, the switching mechanism according to the invention, including the retaining ring, can first be pre-produced as a semi-finished product and then inserted as a whole into a switch housing. This significantly simplifies not only the positioning of the switching mechanism, but also the manufacture of the temperature-dependent switch and the electrical contacting of the switching mechanism.

[0024] Due to the additional retaining ring now provided on the switching mechanism, the housing of the temperature-dependent switch can be constructed much more simply than before. Essentially, the switch housing only requires two external connections, which are electrically connected to each other via the switching mechanism according to the invention.

[0025] According to the invention, a temperature-dependent switch is therefore also provided, which has a temperature-dependent switching mechanism and a switch housing surrounding the switching mechanism, wherein the temperature-dependent switching mechanism is configured to switch between a closed position, in which the switching mechanism establishes an electrically conductive connection between a first external terminal and a second external terminal, and an open position, in which the temperature-dependent switching mechanism disconnects the electrically conductive connection, depending on its temperature.

[0026] According to the invention, a clamping element is arranged in the base body and the circumferential edge of the spring disc is arranged between the clamping element and the base body.

[0027] The clamping element is preferably an annular clamping element that contacts the circumferential edge of the spring washer along its entire circumference and clamps it between itself and the base of the retaining ring. The clamping connection created by the clamping element preferably does not result in high contact pressure, but rather ensures a loose clamping of the spring washer (with play) or at least a clamping with a comparatively low clamping force. It is only important that the spring washer is held securely to the retaining ring and that an electrical contact is established between the retaining ring and the spring washer. A clamping arrangement with excessively high clamping force should be avoided to prevent deformation of the spring washer.

[0028] While the base of the retaining ring is made of electrically conductive material, preferably metal, the clamping element is made of an electrically insulating material, e.g. plastic.

[0029] The above-mentioned task has therefore been completely solved.

[0030] In one embodiment, the retaining ring does not touch the bimetallic disc. Instead, the retaining ring leaves a circumferential edge of the bimetallic disc freely accessible, at least from one upper surface of the bimetallic disc.

[0031] The bimetallic disc is thus held in place only indirectly via the contact element on the retaining ring, without direct contact with it. This has the particular advantage that the circumferential edge of the bimetallic disc is freely movable and can be supported without force in the closed position (low-temperature position) of the switch. The movement of the bimetallic disc is preferably not restricted by the retaining ring in either the closed or open position of the switch.

[0032] According to a further embodiment, the retaining ring surrounds the circumferential edge of the spring disc from a circumferential side of the spring disc, a top side of the spring disc extending transversely to the circumferential side, and a bottom side of the spring disc opposite the top side, each at least partially.

[0033] The retaining ring is preferably designed to completely encircle the circumferential side of the spring washer, while only partially encircling the top and bottom surfaces, specifically in the area of ​​the washer's circumferential edge. Despite this, the retaining ring is relatively compact, so that it hardly increases the size of the switch mechanism itself compared to conventional temperature-dependent switches of this type. Since, as already mentioned, the additional retaining ring allows for the elimination of components on the switch housing or a simpler design of the switch housing, the overall size of the switch is not increased by the retaining ring.

[0034] According to a further embodiment, the circumferential edge of the spring washer is clamped in the retaining ring.

[0035] Attaching the spring washer to the retaining ring is therefore extremely simple. At the same time, the clamping connection between the retaining ring and the spring washer ensures a mechanically stable connection of the switchgear unit, which consists of a bimetallic disc, spring washer, contact part and retaining ring and is held together permanently.

[0036] According to a further embodiment, the base body of the retaining ring extends around a central axis and defines a receiving pocket open towards the central axis, in which the clamping element and the circumferential edge of the spring washer are arranged.

[0037] This receiving pocket preferably extends at least along a circumferential section of the retaining ring. The receiving pocket thus extends at least partially around the central axis of the retaining ring's base body. The receiving pocket can also extend completely around the central axis.

[0038] The receiving pocket is preferably essentially U- or J-shaped in cross-section. U-shaped specifically means that, viewed in cross-section, the receiving pocket is formed by two parallel or essentially parallel legs connected by a transverse leg. The two parallel or essentially parallel legs need not necessarily be of the same length (hence the term J-shaped). Furthermore, the receiving pocket formed by the base body of the retaining ring can be either square or rounded in cross-section.

[0039] The recess formed by the base of the retaining ring allows for very easy installation of the derailleur. For example, the base can be bent around the clamping element, and the spring washer can then be positioned between the clamping element and the base of the retaining ring. Alternatively, the base can be manufactured first, and the clamping element and spring washer inserted into it, either together or sequentially.

[0040] The base body of the retaining ring is preferably rotationally symmetrical. The base body of the retaining ring is preferably a body of revolution. Furthermore, the base body is preferably formed in one piece, i.e., from a single integral component.

[0041] According to a further embodiment, the bimetallic disc and the spring disc are arranged one above the other in a vertical direction, wherein the height of the contact part measured in the vertical direction is greater than the height of the retaining ring measured in the vertical direction.

[0042] The retaining ring is therefore designed to be very flat and consequently contributes little or nothing to increasing the overall height of the switch.

[0043] According to a further embodiment, the contact part is arranged centrally relative to the retaining ring and protrudes from it at least on one side.

[0044] The retaining ring thus defines a central through-hole around which the base of the retaining ring extends, and in which the other components of the switching mechanism (bimetallic disc, spring disc, and contact element) are arranged. Due to the low height of the retaining ring, the contact element protrudes from it at least on one side, and in some cases also on the opposite side.

[0045] The retaining ring thus does not restrict the spatial accessibility of the contact part. Accordingly, the electrical contact of the contact part is also not restricted by the retaining ring. Preferably, the contact part is accessible from two opposite sides, i.e., from its top and bottom, and is not surrounded by the retaining ring on these sides.

[0046] According to a further embodiment, the inner diameter of the base body of the retaining ring is smaller than the outer diameter of the spring washer, but larger than the outer diameter of the bimetallic disc.

[0047] This ensures that the spring washer is held captive on the base of the retaining ring, while the outer edge of the bimetallic disc does not collide with the retaining ring when the bimetallic disc moves.

[0048] The inner and outer diameters mentioned refer to dimensions of the retaining ring, bimetallic disc, or spring washer, measured transversely, preferably perpendicular to the vertical direction.

[0049] According to a further embodiment, the contact part has a first component and a second component attached to the first component, wherein a centrally arranged inner edge of the spring disc is clamped between the first and the second component, and wherein a centrally arranged inner edge of the bimetallic disc is arranged between the second component and the spring disc.

[0050] The contact element is therefore preferably constructed in two parts. While the spring washer is clamped between the two components of the contact element with its inner edge, the inner edge of the bimetallic disc is positioned between the inner edge of the spring washer and the second component and has some play. This, in turn, has a positive effect on the service life of the bimetallic disc, as it can thus be mounted without force in the closed position of the switch.

[0051] As already mentioned at the outset, the present invention relates not only to the temperature-dependent switching mechanism, but also to a temperature-dependent switch in which the temperature-dependent switching mechanism according to the invention is used. It is therefore understood that the features of the aforementioned embodiments, as well as the features defined in the dependent claims relating to the temperature-dependent switching mechanism, also apply in the same or equivalent manner to the temperature-dependent switch according to the invention.

[0052] According to one embodiment of the temperature-dependent switch according to the invention, the switch housing has a lower part and a cover part attached to the lower part, which closes the lower part, wherein the lower part and the cover part are made of electrically insulating material.

[0053] For example, both the base and the cover are made of plastic. This offers a significant cost advantage compared to switch housing components made of metal.

[0054] Manufacturing the switch housing from electrically insulating material is possible, among other reasons, because the retaining ring of the switching mechanism is made of electrically conductive material and can therefore function as an electrode of the switch or switching mechanism. In conventional switching mechanisms designed without such a retaining ring, typically at least part of the switch housing, or even both parts (the bottom and top), function as electrode(s), so the corresponding part of the switch housing must then be made of electrically conductive material.

[0055] According to a further embodiment, the retaining ring forms a first electrode, wherein the lower part carries the first electrode and a second electrode electrically connected to the second external connection and holds the two electrodes at a distance from each other along a vertical direction, wherein the first electrode is electrically connected to the first external connection via a conductor connecting element arranged in the lower part and oriented transversely to the two electrodes, and wherein the first and the second external connection are passed through the lower part at the same height with respect to the vertical direction.

[0056] The connecting element provided inside the switch housing according to this design, which electrically connects the retaining ring (functioning as the first electrode) to the first external terminal, makes it possible to route both external terminals through the lower part at the same height, even though the two electrodes are arranged at different heights inside the switch. Arranging the two external terminals at the same height significantly simplifies the electrical connection of the switch.

[0057] The conductor connection element is preferably a separate component that acts as an electrical conductor between the first electrode and the first external terminal and is electrically connected internally to the first electrode (i.e., the retaining ring) on ​​one side and to the first external terminal on the other. For example, it could be a conductor plate located in the lower part of the switch housing and positioned between the first electrode and the first external terminal.

[0058] According to one embodiment, the retaining ring rests on the conductor connection element.

[0059] The electrical connection of the switching mechanism is thus achieved in a remarkably simple manner: the switching mechanism is inserted into the lower part of the switch housing in such a way that the retaining ring rests on the conductor connection element. This contact ensures a surface connection between the retaining ring and the conductor connection element, resulting in good and reliable contact of the switching mechanism.

[0060] According to a further embodiment, the bimetallic disc is arranged to change its shape depending on its temperature in order to switch the switching mechanism between the closed position and the open position, wherein the spring disc is arranged to establish the electrically conductive connection in the closed position of the switching mechanism by supporting itself on the retaining ring and generating a mechanical contact pressure with which the contact part is pressed against a stationary counter-contact.

[0061] The retaining ring thus serves as the first electrode of the switching mechanism. The stationary counter-contact serves as the second electrode of the switching mechanism or is located at the second electrode of the switching mechanism. In the closed position, the current flows through the retaining ring, the spring washer, the contact element, and the stationary counter-contact. The bimetallic disc, however, is de-energized in the closed position of the switch. This, in turn, has a positive effect on the service life of the bimetallic disc and thus on the service life of the switching mechanism.

[0062] It is understood that the features mentioned above and those to be explained below can be used not only in the combinations specified, but also in other combinations or on their own, without leaving the scope of the present invention.

[0063] An embodiment of the present invention is shown in the drawings and is explained in more detail in the following description. The drawings show: Fig. 1 a schematic sectional view of an embodiment of a temperature-dependent switch according to the invention with a temperature-dependent switching mechanism according to the invention, wherein the temperature-dependent switching mechanism of the switch is in its closed position; Fig. 2 a schematic sectional view of the in Fig. 1 The embodiment of the switch according to the invention is shown, wherein the temperature-dependent switching mechanism of the switch is in its open position; Fig. 3 is a schematic top view of the switch. Fig. 1 and 2 The switch shown, wherein components inside the switch are shown with dashed lines; and Fig. 4 a schematic top view of the switching mechanism according to the invention in an exemplary embodiment.

[0064] Fig. 1 and 2 Each figure shows a schematic sectional view of an embodiment of a temperature-dependent switch according to the invention, in which a switching mechanism according to the invention is used. The switch as a whole is designated by the reference numeral 10.

[0065] Fig. 1 shows the closed position of switch 10. Fig. 2 shows the open position of switch 10.

[0066] The switch 10 has a temperature-dependent switching mechanism 12 according to the invention. The switching mechanism 12 is configured to switch the switch 10 from its closed position to its open position and vice versa, depending on its temperature.

[0067] In the Fig. 1 In the closed position of switch 10 shown, the switching mechanism 12 establishes an electrically conductive connection between the two external terminals 14, 16 of switch 10. In the Fig. 2 In the open position of the switch 10 shown, the switching mechanism 12 disconnects the electrically conductive connection between the first external terminal 14 and the second external terminal 16.

[0068] The temperature-dependent switching mechanism 12 comprises a temperature-dependent bimetallic disc 18, a temperature-independent spring disc 20, a movable contact element 22, and a retaining ring 24. The aforementioned components 18-24 of the switching mechanism 12 are captive connected to one another.

[0069] The spring washer 20 has a central hole through which the contact part 22 passes. The inner edge 26 of the spring washer 20 is clamped to the contact part 22. More precisely, the contact part 22 is composed of two parts: a first component 28, which forms the main body of the contact part 22, and a second component 30, which is designed as a kind of circumferential shoulder and is firmly connected to the first component 28 of the contact part 22. The spring washer 20 is clamped between the first component 28 and the second component 30 of the contact part 22 by its inner edge 26.

[0070] The circumferential rim 32 of the spring washer 20 is captive and held in place by the retaining ring 24. The retaining ring 24 has a base body 34 and a clamping element 36 arranged in the base body 34. The base body 34 of the retaining ring 24 is made of metal or another electrically conductive material. This base body 34 is a rotationally symmetrical body that extends around a central axis 38 and forms a kind of receiving pocket 40 in which the clamping element 36 and the circumferential outer rim 32 of the spring washer 20 are arranged.

[0071] The receiving pocket 40 formed by the base body 34 of the retaining ring 24 is, as shown in Fig. 1 and 2The retaining ring 24 is shown open towards the central axis 38 and essentially U- or J-shaped in cross-section. The receiving pocket 40 formed by the base body 34 of the retaining ring 24 extends at least partially along the retaining ring 24. It can, but does not necessarily have to, run along the entire circumference of the retaining ring 24, as will be explained in more detail below.

[0072] The clamping element 36 is preferably a spacer ring designed as a body of revolution and adapted to the shape of the retaining ring or the shape of the receiving pocket 40 formed by the base body 34. This spacer ring is preferably fitted precisely into the receiving pocket 40. The spacer ring or clamping element 36 is preferably made of electrically insulating material, e.g., plastic.

[0073] While the spring washer 20 is clamped with its circumferential edge 32 between the base body 34 and the clamping element 36 of the retaining ring 24 and is clamped to the contact part 22 with its inner edge 26, the bimetallic disc 18 is in the Fig. 1 In the closed position of the switching mechanism 12 shown, the bimetallic disc 18 is mounted largely without force. Its inner edge 42 is positioned between the second component 30 of the contact part 22, which is designed as a circumferential shoulder, and the spring washer 20. This arrangement ensures that the bimetallic disc 18 is captive but held with some play on the contact part 22. In the closed position of the switching mechanism 12, the circumferential edge 44 projects into the interior of the switch and has no contact with either the retaining ring 24 or the switch housing 46 in which the switching mechanism 12 is located. The circumferential edge 44 of the bimetallic disc 18 is therefore freely accessible, at least from the top, and is not obscured from this side by the retaining ring 24.

[0074] The retaining ring 24, on the other hand, surrounds the circumferential edge 32 of the spring washer 20 both from the circumferential side 48 and from the top and bottom 50, 52 of the spring washer 20.

[0075] The bimetallic disc 18 and the spring disc 20 are arranged one above the other in the vertical direction h. A height H1 of the contact part 22, measured in the vertical direction h, is greater than a height H2 of the retaining ring 24, also measured in the vertical direction h. Accordingly, the contact part 22 projects in the Fig. 1 In the closed position shown, the switch mechanism 12 extends downwards out of the retaining ring 24. In the Fig. 2 In the closed position shown, the contact part 22 protrudes from the retaining ring 24 on both sides (downwards and upwards).

[0076] As from the in Fig. 4 As can be seen in the top view of the switching mechanism 12, the inner diameter d 1 of the base body 34 of the retaining ring 24 is smaller than the outer diameter D 1 of the spring washer 20, but larger than the outer diameter D 1 of the bimetallic disc 18. This ensures that the spring washer 20 is captive and cannot be unintentionally detached from the retaining ring 24. Furthermore, this ensures that the bimetallic disc 18 does not collide with the retaining ring 24 during its temperature-dependent movement.

[0077] The base body 34 of the retaining ring 24 is designed as a single piece. It has a ceiling wall 54, a floor wall 56 integrally connected to the ceiling wall 54 and running parallel to it, and a side wall 58 running transversely to the ceiling wall 54 and the floor wall 56. The side wall 58 connects the ceiling wall 54 to the floor wall 56 and is integrally connected to both.

[0078] While the side wall 58 extends along the entire circumference of the base body 34 of the retaining ring 24, the top wall 54 and the bottom wall 56 of the base body 34 of the retaining ring 24 do not necessarily have to extend all the way around. Although it is generally possible for the top wall 54 to extend along the entire circumference of the base body 34 of the retaining ring 24, to avoid wrinkling it, it is advantageous if the top wall 54 of the base body 34 of the retaining ring 24 has several separate, circumferentially distributed, bent segments 60, as shown in the top view in Fig. 4 shown.

[0079] The switching mechanism 12 is inserted as a whole into the switch housing 46 during the manufacture of the switch 10. This switch housing 46 has a cup-shaped lower part 62, which is closed by a separately designed cover part 64. In the switch according to the invention, both the lower part 62 and the cover part 64 are made of electrically insulating material, e.g., plastic. The upper edge 66 of the lower part 62 is vacuum-formed to the cover part. For example, during the manufacture of the switch 10, the upper edge 66 of the lower part 62 is formed radially inwards by hot stamping, so that the lower part 62 is firmly connected to the cover part 64 and the interior of the switch is sealed, in order to protect, in particular, the switching mechanism 12 from penetrating moisture or other contaminants entering the interior of the switch.

[0080] Due to the construction of the lower part 62 and the cover part 64 from electrically insulating material, the switch housing 46 itself does not serve as the electrical connection for the switching mechanism 12. Instead, the base body 34 of the retaining ring 24, which is made of electrically conductive material, functions as the first electrode 68. A second electrode 70 is embedded in the lower part 62 of the switch housing 46. This second electrode 70 is integrally connected to the second external terminal 16. The second electrode 70 can, for example, be a metal sheet that is directly integrated into the lower part 62 of the switch housing 46. For instance, during the manufacture of the switch 10, the lower part 62 is produced as a plastic injection-molded part by overmolding the second electrode 70.

[0081] The two electrodes 68, 70 of the switching mechanism 12 are held at a distance from each other in the vertical direction h by the lower part 62 of the switch housing 46. The retaining ring 24 rests on top of a shoulder 72 formed inside the lower part and is simultaneously in surface contact with a conductor connection element 74, which is electrically connected to the first external terminal 14. This conductor connection element 74 can be, for example, a conductor plate or another electrical conductor integrated into the lower part 62 of the switch housing 46.

[0082] The connecting element 74 electrically connects the base body 34 of the retaining ring 24, which serves as the first electrode 68 of the switching mechanism 12, to the first external terminal 14. In this way, it is possible to route the two external terminals 14, 16 through the lower part 62 of the switch housing 46 from the inside to the outside at the same height, despite the offset arrangement of the two electrodes 68, 70 in the vertical direction h. The first external terminal 14 is accordingly located in the Fig. 1 and 2 The sectional views shown are arranged "behind" the second external connection 16, since the first external connection 14 is arranged at the same level as the second external connection 16 and runs parallel to the second external connection 16. The latter is particularly evident from viewing it together with the view shown in Fig. 3 The top view of switch 10 is shown.

[0083] The two external connections 14, 16 run as shown in Fig. 3 shown, outside the switch housing 46 parallel to each other and can be connected in a common connection plane E due to the line connection element 74, which is in Fig. 1 and 2 The arrangement is indicated by a dotted line.

[0084] The line connection element 74 also offers the advantage that the switching mechanism 12 only needs to be inserted into the lower part 62 during the manufacture of the switch 10 and the electrical contact between the base body 34 of the retaining ring 24 and the first external connection 14 is then automatically established.

[0085] It should be noted at this point that Fig. 3 Figure 10 shows a top view of switch 10, with some components located inside the switch housing 46 (e.g., components 18, 20, and 34) indicated by dashed lines, as these are not actually visible from the outside. The dashed lines indicate the outline or outer circumference of each component. The second electrode 70, which is located in Fig. 3 which is also indicated by dashed lines, runs diagonally or at an angle to the second external connection 16, but, as already mentioned, lies together with the second external connection 16 in the connection plane E. Fig. 1 and 2 They therefore show the section along the section line AA.

[0086] It is further understood that the conductor connection element 74, in the case of such a cutting line AA and its in Fig. 3 arrangement shown in Fig. 1 and 2 formally not visible, but would be concealed by parts of the lower housing section 62. In the case of the Fig. 1 and2 However, the views shown are not to scale and in detail, but rather schematic sectional views in which the line connection element 74 is shown schematically for better explanation of its arrangement.

[0087] It is also understood that the second electrode 70 does not necessarily have to run at an angle or obliquely to the second external connection 16, as shown in Fig. 3 The second electrode 70 can also be aligned with the second external terminal 16. In such a case, it is preferred that the second external terminal 16 runs radially with the second electrode 70 along the switch housing 46. If the second external terminal 16 is located centrally, i.e., opposite the one shown in Fig. 3 Even if the two external connections 14 and 16 are arranged in the position shown, parallel upwards in the direction of the first external connection 14, a parallel alignment of the two external connections 14 and 16 is still possible. With regard to Fig. 3 The second external terminal 16 and the second electrode 70 will then be arranged in a line parallel to the first external terminal 14 in the center of the switch housing 46.

[0088] The temperature-dependent switching function of switch 10, which is effected by the temperature-dependent switching mechanism 12, is described below. Fig. 1 and 2 explained.

[0089] Fig. 1 As already mentioned, this shows the closed position of switch 10, in which the temperature-dependent switching mechanism 12 establishes an electrical contact between the two external terminals 14 and 16 within the switch. In this closed position, the spring washer 20 presses the contact part 22 against a stationary mating contact 76, which is attached to the second electrode 70. The bimetallic disc 18 is de-energized and free of force in the closed position of switch 10. The contact pressure and the current flow are caused solely by the spring washer 20. The spring washer 20 rests with its circumferential edge 32 against the clamping element 36 and presses the centrally arranged contact part 22 against the mating contact 76. The current flows from the first external terminal 14 via the connecting element 74. , the retaining ring 24 ,the spring washer 20, the movable contact part 22, the stationary counter contact 76 and the second electrode 70 to the second external terminal 16 (or in reverse direction).

[0090] In the Fig. 1 In the closed position or low-temperature position of switch 10 shown, the spring disc 20 is in its first configuration and the bimetallic disc 18 is in its low-temperature configuration. If, starting from this situation, the temperature of the device to be protected, and thus the temperature of switch 10 and the temperature of the bimetallic disc 18, rises to or above the response temperature of the bimetallic disc 18, the bimetallic disc 18 snaps from its closed position. Fig. 1 The shown convex low-temperature position transforms into its concave high-temperature position, which in Fig. 2 As shown. During this snapping action, the bimetallic disc 18 rests with its outer edge 44 against the spring disc 20. This simultaneously bends the spring disc 20 upwards at its center, so that the spring disc 20 is displaced from its position in Fig. 1 shown, first stable geometric configuration in their in Fig. 2 The second geometrically stable configuration shown snaps into place. This lifts the contact part 22 away from the mating contact 76 and interrupts the electrically conductive connection between the two outer terminals 14, 16.

[0091] The device to be protected is accordingly disconnected from the power supply so that it can cool down again. If the temperature subsequently falls below the so-called return temperature of the bimetallic disc 18, it snaps back from its position. Fig. 2 high temperature setting shown in their Fig. 1shown low-temperature setting, thereby restoring the electrically conductive connection between the two external terminals 14 , 16 is closed again. Depending on the application, such a re-switching can be prevented by a re-switching lock or a heating resistor connected electrically in parallel to the switching mechanism 12, which effects a so-called self-holding function.

[0092] It is understood that various further modifications of the switch 10 according to the invention are possible compared to the embodiment shown in the drawings, without departing from the scope of the present invention. For example, the switch housing 46 need not be circular in longitudinal section, but can also be oval or rectangular. Accordingly, the two discs 18, 20 need not necessarily be circular. The shape of the retaining ring 24, as well as the shape of the contact part 22, can also be somewhat different and need not necessarily have the exact shape shown in the present drawings.

Claims

1. A temperature-dependent switching mechanism (12) for a temperature-dependent switch (10), wherein the switching mechanism (12) includes: - a temperature-dependent bimetal disc (18); - a temperature-independent spring disc (20); - an electrically conductive contacting part (22) on which the bimetal disc (18) and the spring disc (20) are captively held; and - a retaining ring (24) which comprises a main body (34) that is made of an electrically conductive material and surrounds a peripheral edge (32) of the spring disc (20) and, as a result, captively holds the spring disc (20), characterized in that a clamping element (36) made of electrically insulating material is arranged in the main body (34), and the peripheral edge (32) of the spring disc (20) is arranged between the clamping element (36) and the main body (34).

2. The temperature-dependent switching mechanism according to claim 1, wherein the retaining ring (24) does not contact the bimetal disc (18), and permits a peripheral edge (44) of the bimetal disc (18) to be freely accessible at least from an upper side of the bimetal disc (18).

3. The temperature-dependent switching mechanism according to claim 1 or 2, wherein the retaining ring (24) at least partially surrounds in each case the peripheral edge (32) of the spring disc (20) from a circumferential side (48) of the spring disc (20), an upper side (50) of the spring disc (20) running transversely to the circumferential side (48), and a lower side (52) of the spring disc (20) that lies opposite the upper side (50).

4. The temperature-dependent switching mechanism according to one of claims 1-3, wherein the peripheral edge (32) of the spring disc (20) is arranged so as to be clamped in the retaining ring (24).

5. The temperature-dependent switching mechanism according to one of claims 1-4, wherein the main body (34) of the retaining ring (24) extends about a central axis (38) and defines a receptacle pocket (40) which is open towards the central axis (38) and in which the clamping element (36) and the peripheral edge (32) of the spring disc (20) are arranged.

6. The temperature-dependent switching mechanism according to one of claims 1-5, wherein the main body (34) is configured in one piece.

7. The temperature-dependent switching mechanism according to one of claims 1-6, wherein the bimetal disc (18) and the spring disc (20) are arranged on top of one another in a height direction (h), and wherein a height (H1) of the contacting part (22) measured in the height direction (h) is larger than a height (H2) of the retaining ring (24) measured in the height direction (h).

8. The temperature-dependent switching mechanism according to one of claims 1-7, wherein the contacting part (22) is arranged so as to be centric relative to the retaining ring (24) and protrudes from the latter at least on a first side.

9. The temperature-dependent switching mechanism according to one of claims 1-8, wherein an internal diameter (d1) of the main body (34) of the retaining ring (24) is smaller than an external diameter (D1) of the spring disc (20) but larger than an external diameter (D2) of the bimetal disc (18).

10. A temperature-dependent switch (10) having a temperature-dependent switching mechanism (12) according to one of claims 1-9 and a switch housing (46) surrounding the switching mechanism (12), wherein the temperature-dependent switching mechanism (12), as a function of its temperature, is configured to switch between a closed position in which the switching mechanism (12) establishes an electrically conducting connection between a first external terminal (14) and a second external terminal (16), and an open position in which the temperature-dependent switching mechanism (12) disconnects the electrically conducting connection.

11. The temperature-dependent switch according to claim 10, wherein the switch housing (46) comprises a lower part (62), and a cover part (64) which is fastened to the lower part (62) and closes the lower part (62), wherein the lower part (62) and the cover part (64) are made of an electrically isolating material.

12. The temperature-dependent switch according to claim 10 or 11, wherein the retaining ring (24) forms a first electrode (68), and wherein the lower part (62) supports the first electrode (68) and a second electrode (70) electrically connected to the second external terminal (16) and holds the two electrodes (68, 70) at a mutual spacing along a height direction (h), wherein the first electrode (68) is electrically connected to the first external terminal (14) by way of a line connection element (74) which is aligned transversely to the two electrodes (68, 70) and arranged in the lower part (62), and wherein the first and the second external terminal (14, 16) are led through the lower part (62) at the same height in terms of the height direction (h).

13. The temperature-dependent switch according to claim 12, wherein the retaining ring (24) bears on the line connection element (74).

14. The temperature-dependent switch according to one of claims 10 to 13, wherein the bimetal disc (18), as a function of its temperature, is configured to change its shape so as to switch the switching mechanism (12) between the closed position and the open position, and wherein the spring disc (20) in the closed position of the switching mechanism (12) is configured to establish the electrically conducting connection in which said spring disc (20) is supported on the retaining ring (24) and generates a mechanical contact pressure by way of which the contacting part (22) is pressed against a stationary mating contact (76).

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