Temperature-dependent switching mechanism and temperature-dependent switch having temperature-dependent switching mechanism

Abstract

To provide a temperature-dependent switching mechanism that is not susceptible to damage and can be pre-produced as a semi-finished product.SOLUTION: A temperature-dependent switching mechanism (10) for a temperature-dependent switch (100) includes a bimetallic element (12), a spring element (14), a conductive contact (16) on or secured to the spring element (14), and at least one retention pawl (18) on or secured to the spring element (14), the at least one retention pawl (18) has a support surface (34), the bimetallic element (12) is configured to snap from a low temperature configuration to a high temperature configuration upon exceeding a response temperature, the bimetallic element (12) is supported on the support surface (34) in its high temperature configuration.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a temperature dependent switching mechanism for a temperature dependent switch.The present invention further relates to a temperature dependent switch having such a temperature dependent switching mechanism. [Background technology]

[0002] A large number of temperature-dependent switching mechanisms and switches with such temperature-dependent switching mechanisms are already known in principle. Exemplary temperature-dependent switching mechanisms and switches are disclosed in DE 10 2011 119 632 A1, DE 10 2022 118 405 A1 and DE 10 2013 017 232 A1.

[0003] Such temperature-dependent switches are primarily used in a known manner to monitor the temperature of an apparatus: 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 protected device affects the temperature of the switching mechanism arranged inside the switch.

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

[0005] In the switch disclosed in DE 10 2011 119 632, the switching mechanism is arranged inside the switch housing. The switch housing is formed from two parts. The switch housing comprises a lower part, which is rigidly connected to the cover part via an insulating foil. The temperature-dependent switching mechanism arranged in the switch housing comprises a spring element to which a movable contact is fixed and a bimetallic element arranged on the movable contact part. The spring element presses the movable contact part against a fixed counter contact part arranged inside the switch housing in the cover part. The outer edge of the spring element, configured as a snap-action spring disk, is supported on the lower part of the switch housing, and the current flows from the lower part through the snap-action spring disk and the movable contact part to the fixed counter contact part and from the contact part to the cover part.

[0006] The temperature-dependent bimetallic element, in the case of the switch disclosed in DE 10 2011 119 632, is disk-shaped, often called bimetallic snap-action disk, and is essentially responsible for the temperature-dependent switching behavior of the switching mechanism. This bimetallic element is usually constructed as a multi-layered active sheet-like device consisting of two, three or four interconnected parts with different thermal expansion coefficients. The connection of the individual metal or metal alloy layers in this type of bimetallic element is usually a material-locking or positive-locking connection, achieved for example by rolling.

[0007] Such a bimetallic element has a first geometric configuration (cold configuration) that is stable at low temperatures below the response temperature of the bimetallic element, and a second geometric configuration (hot configuration) that is stable at high temperatures above the response temperature of the bimetallic element, and the bimetallic element snaps from its cold configuration to its hot configuration in a temperature-dependent manner in a hysteretic manner.

[0008] Thus, if the temperature of the bimetallic element rises above its response temperature as a result of a temperature increase in the device to be protected, the bimetallic element snaps from its cold configuration to its hot configuration, whereby it acts against the spring element to lift the movable contact from the fixed opposing contact, thereby opening the switch and switching off the device to be protected so that it does not heat up any further.

[0009] Unless a reset lock is provided, the bimetallic element will snap back to its low temperature configuration, so that the switch is closed again as soon as the temperature of the bimetallic element falls below the so-called reset temperature of the bimetallic element as a result of cooling of the device to be protected.

[0010] In its low temperature configuration, the bimetallic element is preferably mounted in the switch housing in a mechanically non-stressful manner and the bimetallic element is not used to carry current. This has the advantage that the bimetallic element has a longer service life and the switching point, i.e. the response or switching temperature of the bimetallic element, does not change even after many switching cycles.

[0011] Therefore, in the case of many temperature-dependent switches, the bimetallic element is preferably inserted as a loose individual part into the switch housing during the manufacture of the switch, the bimetallic element being placed on the contact fixed to the spring element, for example via a central through-hole provided therein. Only by closing the switch housing is the bimetallic element fixed in its position and its position relative to the other components of the switching mechanism defined. However, the manufacture of such switches, in which the bimetallic elements are inserted individually, proves to be relatively laborious, since several steps are required to insert the switch into the switch housing. Therefore, it is usually difficult to manufacture such switches automatically.

[0012] For this reason, in the switch disclosed in German Patent 10 2011 119 632, the bimetallic element is connected to a contact part which is previously (outside the switch housing) fixed to a spring element. For this purpose, the bimetallic element is placed on the contact part and then the upper collar of the contact part is bent over. As a result, not only is the spring element fixed to the contact part, but the bimetallic element is also restrained and held on the contact part.

[0013] In this way, the switching mechanism, consisting of the bimetallic element, the spring element and the contacts, can be pre-manufactured as a semi-finished product, which forms the arresting unit and can be stored separately as bulk material. When the switch is manufactured, the switching mechanism can be inserted as a arresting unit into the switch housing in just one work step. This simplifies the production of the switch many times over.

[0014] In the switch disclosed in German Patent 10 2011 119 632, the spring element is welded or soldered to the contact in order to achieve the best possible electrical contact between the two parts. However, it has been shown that the welded or soldered connection between the contact and the spring element can break, especially if the switch is stored in bulk as a semi-finished product. Such a defective switch can of course no longer be inserted. It is problematic, among other things, that such defects can only be detected after the switch has been assembled and only then is it possible to test the function of the switching mechanism.

[0015] In particular, the latter point is improved in the switching mechanism disclosed in DE 10 2022 118 405. The switching mechanism disclosed therein comprises a further switching mechanism housing in which the switching mechanism unit, including the bimetallic element, the spring element and the contacts, is held restrictively but with play. This further switching mechanism housing not only allows the pre-production of the switching mechanism as a semi-finished product, but also protects the fragile parts of the switching mechanism against damage, in particular during storage. This also simplifies the installation of the switching mechanism in the switch. Furthermore, the further switch housing has the advantage that the switching mechanism can be functionally tested before being installed in the switch, since the snap-action behavior of the bimetallic element can already be tested in the switch housing.

[0016] A similarly advantageous solution is disclosed in DE 10 2013 017 232 A1. The temperature-dependent switching mechanism disclosed therein comprises an annular frame in which a bimetallic element and a spring element are held in a restrained manner. This arrangement also protects sensitive devices of the switching mechanism during storage. Furthermore, a functional test of the switching mechanism is possible even before it is mounted on a switch or a housing of the switching mechanism.

[0017] Although especially the latter two solutions have proven advantageous, there is still room for further improvement. In particular, the manufacturability of the switching mechanism can be improved and its size can be further reduced. Furthermore, further simplifications and improvements should lead to further cost reductions. Summary of the Invention [Problem to be solved by the invention]

[0018] It is therefore an object of the present invention to provide a temperature-dependent switching mechanism which is further improved, in particular in the above-mentioned respects. In particular, it is an object to provide a temperature-dependent switching mechanism which is not susceptible to damage leading to defects of the switching mechanism and which can be pre-produced as a semi-finished product and stored as bulk material. A switching mechanism which is pre-produced as a semi-finished product is nevertheless as easy as possible to use in a temperature-dependent switch and allows the switching mechanism to be manufactured in as few work steps as possible. It should also be possible to test the function of the switching mechanism before it is attached to the switch. [Means for solving the problem]

[0019] According to the invention, this object is achieved by a temperature dependent switching mechanism comprising: A bimetallic element; A spring element; a conductive contact provided on or fixed to the spring element; at least one retaining claw provided on or fixed to the spring element; At least one of the retaining jaws includes a support surface; The bimetallic element is configured to snap from a cold configuration to a hot configuration upon exceeding a response temperature, the bimetallic element being supported on a support surface in the hot configuration.

[0020] The switching mechanism according to the invention therefore comprises one or more retaining pawls, which are provided on or fixed to the spring element and serve to retain the bimetallic element, with at least one retaining pawl not only retaining the bimetallic element and preventing it from detaching from the switching mechanism, but also at the same time protecting the bimetallic element during bulk storage of the switching mechanism.

[0021] At least one retaining claw comprises a support surface on which the bimetallic element is supported in its hot configuration. This has the advantage that a functional test can be carried out with the switching mechanism according to the invention even before the switching mechanism is installed in a switch. The bimetallic element can assume both its states / configurations (cold and hot configuration) within the switching mechanism without the need for further components.

[0022] Compared to the switching mechanisms of the prior art mentioned at the beginning, the switching mechanism according to the invention is significantly more compact, simpler and in particular consists of fewer components. Since at least one retaining claw is provided, a housing for the switching mechanism as proposed in DE 10 2022 118 405 is no longer necessary. Since at least one retaining claw is provided on the spring element according to the invention, for example formed integrally with the spring element or fixed to the spring element, the switching mechanism according to the invention is also significantly smaller or more compact than the switching mechanism disclosed in DE 10 2022 118 405.

[0023] A ring-shaped 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. By means of a support surface arranged thereon, the bimetallic element according to the invention can be supported directly on the retaining claw in its hot configuration, which is advantageous in contrast to the switching mechanism disclosed in DE 10 2013 017 232 A1, in which the bimetallic element is supported directly on a spring element in its hot configuration, which in particular releases the spring element and makes the switching mechanism overall more durable.

[0024] In this way, the above objective is completely achieved.

[0025] In a refinement, the bimetallic element, the spring element and the contacts form a switching mechanism unit that is restrainingly held together.

[0026] Thus, the individual parts of the switching mechanism unit cannot come apart from one another. On the one hand, this has the advantage that the switching mechanism can be prefabricated as a semi-finished product and can be stored more easily and reliably as bulk material or on a conveyor belt. Furthermore, the switching mechanism with all its individual parts can be inserted as a whole into the switch housing, which simplifies the assembly of the switch and thus facilitates automation.

[0027] In a further refinement, the bimetallic element is captured and held in the contact portion and / or is captured and held in the spring element by at least one retaining claw.

[0028] This prevents loss of the bimetallic element, especially during storage on a belt or as bulk material, and also ensures that the bimetallic element will not become dislodged from the switching mechanism when used in conjunction with a switch.The most mechanically stable and secure method of retaining the bimetallic element is achieved when it is restrained at the contacts and with a spring element by at least one retaining pawl.

[0029] In a further refinement, the at least one retaining claw projects in one direction from a first side of the spring element facing the bimetal element.

[0030] In other words, the at least one retaining claw protrudes from the spring element on the same side as the bimetal element is arranged. The advantage of at least one retaining claw protruding on one side is that the embodiment of the switching mechanism is as space-saving as possible.

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

[0032] In a further refinement, the at least one retaining claw projects in a first direction from a first side of the spring element, the support surface being oriented transversely to the first direction and facing the spring element.

[0033] In this case, the term "transverse" does not necessarily mean orthogonal or perpendicular. Instead, it is understood to mean any type of orientation that is not parallel. Thus, oblique orientations at angles not equal to 0° also fall under the term "transverse."

[0034] According to the abovementioned refinement, the at least one retaining claw preferably comprises a first part protruding from the spring element and extending in a first direction and a second part connected to the first part, extending transversely to the first part and arranged with its support surface facing the spring element. Particularly preferably, the at least one retaining claw has an inverted (upside-down) L-shaped cross-sectional shape.

[0035] In a further refinement, the at least one retaining claw comprises at least two retaining claws.

[0036] According to this refinement, 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 refinement each have the same distance from the 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, so that there is rotational symmetry about the central axis.

[0037] An embodiment of several individual retaining claws is typically easier and more cost effective to manufacture than a relatively large continuous retaining claw that extends, for example, along the entire circumference of the bimetallic element or along a majority of the circumference of the bimetallic element (i.e., more than 50% of the circumference of the bimetallic element).

[0038] In a further refinement, the at least one retaining claw is integrally connected to the spring element or is fixed to the spring element in a material-locking manner.

[0039] Thus, the at least one retaining claw can, for example, be formed integrally with the spring element, or preferably, the at least one retaining claw is welded or soldered to the spring element, thereby forming a mechanically very stable retaining claw which is inseparably connected to the spring element.

[0040] In a further refinement, the spring element comprises an outer edge and the at least one retaining claw is spaced apart from the outer edge.

[0041] Preferably, the outer edge is a circumferential outer edge from which the at least one retaining claw is spaced. Particularly preferably, the at least one retaining claw has a smaller distance from the 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 inwards with respect to the outer edge of the spring element, which spring element is, for example, disc-shaped, in particular circular disk-shaped.

[0042] This has the advantage that the switching mechanism according to the invention can be fixed very easily in the switch housing of the switch, since when mounting the switch the outer edge of the spring element can be clamped between two parts of the switch housing to fix the switching mechanism, without impairing the function of the at least one retaining claw.

[0043] In a further refinement, the outer edge lies in one plane and the radially inner region of the spring element is curved.

[0044] This further simplifies the fixing of the switching mechanism in the switch housing. Furthermore, the curved inner region of the spring element allows sufficient freedom of movement of the spring element so that it can move together with the bimetal element during a switching operation.

[0045] In a further refinement, the spring element has a first configuration when the bimetallic element is in its cold configuration and the spring element is brought to the second configuration by the bimetallic element when the bimetallic element snaps to its hot configuration.

[0046] Preferably, the spring element is a snap-action spring disk that has two different configurations or states, similar to a bimetallic element. It is particularly preferred that the two configurations / states of the spring element are mechanically stable configurations / states. However, unlike the two configurations of the bimetallic element, the two configurations / states of the spring element are not temperature dependent.

[0047] In a further refinement, the spring element together with the at least one retaining claw forms an open housing in which the bimetallic element is arranged accessible from the outside, the open housing at least partially enclosing the bimetallic element from a first side, a second side opposite the first side, and a circumferential side extending laterally between the first side and the second side.

[0048] As a result, the bimetallic element is arranged to a certain extent enclosed within a housing formed by the spring element and the at least one retaining claw. This provides good protection of the bimetallic element, which is advantageous in particular when the switching mechanism is stored in bulk. This type of "housing" preferably at least partially surrounds the bimetallic element on all sides, while the bimetallic element is still accessible from the outside, which is crucial for the functioning of the switching mechanism.

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

[0050] This ensures in a simple manner that the bimetallic element is not released from the at least one retaining claw, and is therefore held constrained by the spring element.

[0051] In a further refinement, the switching mechanism is rotationally symmetric about a central axis.

[0052] This also simplifies installation of the switching mechanism since it may be inserted into the switch housing of the switch in any orientation relative to its central axis. Additionally, the symmetrical orientation of the switching mechanism ensures optimal force distribution when the switch is closed.

[0053] In a further refinement, the bimetallic element is provided with an opening through which the contact protrudes, the bimetallic element being preferably disk-shaped, the aforementioned opening being preferably inserted in the center of the bimetallic element, the bimetallic element being placed on contact with said opening.

[0054] In a further refinement, the spring element preferably comprises an electrically conductive material.

[0055] This has the advantage that the spring element can be used as a conductive component, such that current flows through the spring element when the switch is closed, and the current does not have to flow through the bimetallic element when the switch is closed, which reduces the load on the bimetallic element and has a positive effect on its service life.

[0056] As stated at the outset, the invention relates not only to a temperature-dependent switching mechanism, but also to a temperature-dependent switch in which a switching mechanism according to the invention is inserted. It is understood that the above improvements and the features defined in the dependent claims do not only relate to the switching mechanism according to the invention, but also to the switch according to the invention.

[0057] In an improved embodiment of the temperature dependent switch, the temperature dependent switching mechanism is disposed in a switch housing, which comprises a lower portion and a cover portion, and the spring element is clamped between the lower portion and the cover portion. The outer edge of the spring element is preferably clamped between the lower portion and the cover portion of the switch housing. Thus, the switch is relatively easy to install and mechanically stable.

[0058] It is to be understood that the features mentioned above and those to be described below can be used not only in the combinations indicated in each case, but also in other combinations or alone, without departing from the scope of the invention. [Brief description of the drawings]

[0059] Embodiments of the invention are illustrated in the drawings and are explained in more detail in the following description. [Figure 1] 1 is a schematic cross-sectional view of a temperature dependent switching mechanism according to a first embodiment of the present invention, the switching mechanism being in a first switching state; [Diagram 2] 2 is a schematic cross-sectional view of the temperature dependent switching mechanism shown in FIG. 1, the switching mechanism being in a second switching state; [Diagram 3] 4 is a schematic cross-sectional view of a temperature dependent switching mechanism according to a second embodiment of the present invention, the switching mechanism being in a first switching state; FIG. [Figure 4] 1 is a schematic plan view of a spring element that can be used in a temperature dependent switching mechanism according to the present invention; [Diagram 5] 1 is a schematic cross-sectional view of a temperature dependent switch according to an embodiment of the present invention, the switch being in a cold state; [Figure 6] FIG. 6 is a schematic cross-sectional view of the temperature dependent switch shown in FIG. 5, with the switch in its hot state. [Figure 7] 4 is a schematic cross-sectional view of a temperature dependent switch according to a further embodiment of the present invention, the switch being in its cold state; [Figure 8]8 is a schematic cross-sectional view of the temperature dependent switch shown in FIG. 7, the switch being in a hot state. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0060] Figures 1 and 2 show schematic cross-sectional views of a first embodiment of a switching mechanism according to the invention. Figure 1 shows the switching mechanism in a cold state. Figure 2 shows the switching mechanism in a hot state. In each case the switching mechanism is generally designated 10.

[0061] The switching mechanism 10 is a temperature dependent switching mechanism. The switching mechanism 10 has a multi-part configuration. The switching mechanism 10 includes a bimetallic element 12, a spring element 14, a conductive contact 16, and at least one retention pawl 18.

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

[0063] 1 and 2, the bimetallic element 12 is essentially circular and disc-shaped, therefore the bimetallic element 12 is also called a bimetallic disc, and due to its physical characteristics the bimetallic element 12 is also called a bimetallic snap-action disc.

[0064] In the illustrated embodiment, the bimetallic element 12 includes a central opening 20 with which the bimetallic element 12 is positioned over the contact portion 16. In the embodiment shown in Figures 1 and 2, the bimetallic element 12 is positioned over the contact portion 16 without its opening 20 being rigidly connected to the contact portion 16. In other words, the bimetallic element 12 and the contact portion 16 are loosely coupled to each other at this point and are movable relative to each other.

[0065] In this embodiment, the contact 16 is fixed to the spring element 14. More precisely, in this embodiment, the contact 16 is connected to the spring element 14 in a material-locking manner. The contact 16 is, for example, soldered or welded to the spring element 14. For better centering, the contact 16 is provided at its end with an extension 22, which is inserted with the extension 22 into an opening 24 provided in the center of the spring element 14. Approximately in the middle, the contact 16 is provided with a collar 26, with the bottom side of which the contact 16 lies flat on the upper side of the spring element 14. The material-locking connection between the spring element 14 and the contact 16 is preferably provided on the bottom side of the collar 26. The collar 26 provided on the contact 16 also serves to support the bimetal element 12 in its high-temperature configuration (see FIG. 2), as will be explained in more detail below.

[0066] In this respect, it should be noted that the contact portion 16 can also be integrally connected to the spring element 14 instead of being connected in a material-locking manner. In other words, the spring element 14 and the contact portion 16 can be formed as one piece. In this case, the contact portion 16 is preferably formed as a protuberance protruding from the upper side of the spring element 14.

[0067] At least one retaining claw 18 is arranged in the region of an outer edge 28 of the spring element 14. In the embodiment shown in Figures 1 and 2, the at least one retaining claw is fixed to the spring element 14 in a material-locking manner, for example by welding or soldering.

[0068] At least one retaining claw 18 projects in one direction from an upper side 30 of the spring element 14, which in this case is also referred to 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 bimetal element 12.

[0069] More precisely, the at least one retaining claw 18 projects from a first side 30 of the spring element 14 in a first direction 32, which corresponds to the vertical direction in Figures 1 and 2. A support surface 34 is provided on the inside of the at least one retaining claw 18. This support surface 34 extends laterally, preferably perpendicular to the first direction 32. In its hot state, the bimetallic element 12 is supported by its outer edge 36 on this support surface 34, as will be explained in more detail below (see Figure 2).

[0070] Together with the at least one retaining claw 18, the spring element 14 forms a partially open housing, in other words in which the bimetallic element 12 is arranged and held in a restrained manner, 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 in each case a first side 38 of the bimetallic element 12 facing the first side 30 of the spring element 14, an opposite second side 40 of the bimetallic element 12, and a peripheral side 42 of the bimetallic element extending transversely to the first and second sides 38, 40. The open housing formed by the spring element 14 together with the at least one retaining claw 18 comprises an opening 44 on the side facing the second side 40 of the bimetallic element 12, through which the movable contact part 16 is accessible to the outside.

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

[0072] In the cold state of the switching mechanism 10 shown in FIG. 1, the bimetallic element 12 is convexly curved on its second side 40 (top side of the bimetallic element 12). Similarly, the 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 cold state shown in FIG. 1. In other words, in the cold state 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 shifted position, the bimetallic element 12 rests loosely from above on the collar 26 of the contact 16. The free outer edge 36 of the bimetallic element 12 is preferably formed in a substantially force-free state and does not have contact with the spring element 14 and / or at least one retaining pawl 18.

[0073] From this switching state of the switching mechanism 10, when the temperature of the switching mechanism 10 rises above the response temperature of the bimetallic element 12, the bimetallic element 12 snaps (suddenly changes) from the cold state shown in FIG. 1 to the hot state shown in FIG. 2. Here, the second side 40 of the bimetallic element 12 (the upper side of the bimetallic element 12) is curved concavely. Thereby, the bimetallic element 12 is supported by its outer edge 36 on the support surface 34 arranged on at least one retaining claw 18. At the same time, the bimetallic element 12 presses the contact 16 with its inner edge 48 in the direction of the spring element 14. In other words, both the bimetallic element 12 and the spring element 14 are curved downwards, so that not only the bimetallic element 12 is curved concavely on its second side 40 (upper side), but also the spring element 14 is curved concavely on its first side 30 (upper side).

[0074] Since the at least one retaining claw 18 acts as a kind of abutment in the hot state of the switching mechanism 10 on which the bimetal element 12 is supported and, together with its devices 12, 14, 16, 18, also the switching mechanism 10 forms a restrictively held switching mechanism unit in the cold state, a function check of the switching mechanism 10 can also be carried out without further devices, in particular without the need to install the switching mechanism 10 in a temperature-dependent switch. The switching mechanism 10 shown in Figures 1 and 2 therefore forms a separately functioning, packable semi-finished product.

[0075] FIG. 3 shows a schematic cross-sectional view of a second embodiment of a switching mechanism 10 according to the present invention. The basic structure and mode of operation of the switching mechanism 10 do not differ from the first embodiment shown in FIGS. 1 and 2. The basic configuration of the switching mechanism 10 is also at least similar to the first embodiment. However, one difference is that the at least one retaining claw 18 is integrally connected to or formed integrally with the spring element 14. Preferably, the spring element 14 and the at least one retaining claw 18 are formed from thin sheet metal.

[0076] A further difference of this second embodiment shown in Fig. 3 is that the contact portion 16 is now configured as a kind of rivet, which is connected to both the bimetallic element 12 and the spring element 14. In the second embodiment shown in Fig. 3, the bimetallic element is thus not only held to the spring element by at least one retaining claw 18, but also held and held to the contact portion 16. A support ring 50 can be arranged between the bimetallic element 12 and the spring element 14 on the contact portion 16 configured as a rivet. However, a support ring is not necessarily required.

[0077] FIG. 4 shows the spring element 14 of the embodiment of the switching mechanism 10 shown in FIG. 3 in a plan view from above. As can be seen, the spring element 14 is essentially circular disk-shaped, here provided with various recesses 52 in order to reduce the electrical resistance and save material. Instead of a (single) retaining claw 18 extending completely around the circumference, here three retaining claws 18 are provided, which are arranged apart from each other and distributed. More precisely, the three retaining claws are regularly distributed around the circumference of the spring element 14. It is understood that in principle two or more retaining claws 18 can also be provided. Likewise, only a single retaining claw 18 can serve as an abutment for the bimetallic element 12, provided that 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 comprises a peripheral region 58 which lies in a plane, i.e. is flat or planar. The radially inner region 46 of the spring element 14 is formed in the embodiment shown in Figure 4 by three radially extending webs 54 and a central region 56, the inner region 46 being curved.

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

[0080] The spring element 14 is rotationally symmetric about the central axis 60. Similarly, the entire switching mechanism 10 is preferably rotationally symmetric about the central axis 60. Thus, the switching mechanism 10 can be inserted into the switch housing of a switch in any position rotated about the central axis 60. This simplifies assembly of the switching mechanism 10 many times over.

[0081] Figures 5 and 6 show a first embodiment of a temperature dependent switch in which a switching mechanism 10 according to the invention is used. Figure 5 shows the switch in its cold state, and Figure 6 shows the switch in its hot state. In both cases the switch is generally designated by the reference numeral 100. The switch 100 comprises a switch housing 62 which serves as a 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 on the lower part 64 by a bent or flanged upper edge of the latter.

[0082] 5 and 6, both the lower portion 64 and the cover portion 66 are made of an electrically conductive material, preferably metal. Disposed between the lower portion 64 and the cover portion 66 is an insulating foil 68. The insulating foil 68 electrically insulates the lower portion 64 from the cover portion 66. The insulating foil 68 also provides a mechanical seal that prevents liquids or impurities from entering the inside of the housing from the outside.

[0083] The lower portion 64 and the cover portion 66 are each made of an electrically conductive material so that thermal contact to the electrical device to be protected can be established via their outer surfaces. The outer surfaces can also be used for electrical connections of the switch 100. For example, the outer surface 65 of the lower portion 64 serves as a first electrical terminal and the outer surface 67 of the cover portion 66 serves as a second electrical terminal of the switch 100.

[0084] The switching mechanism 10 is arranged clamped between the lower part 64 and the cover part 66. More precisely, the switching mechanism 10 is arranged 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. Thus, with the aid of the spacer ring 70, the switching mechanism 10 can be both fixed and centered. As a result, the movable contact 16 of the switching mechanism 10 is oriented against a fixed opposing contact 72 disposed inside the lower portion 64 of the switch housing 62. This opposing contact 72 is also referred to in this case as the stationary contact.

[0086] In the cold state of the switch 100 shown in Fig. 5, also called the closed state of the switch 100, the switching mechanism 10 establishes a 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 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 fixed contact part 72. The contact pressure between the movable contact part 16 and the fixed contact part 72 is generated by the spring element 14. In this state, the bimetallic element 12 is housed in the switching mechanism 10 in a more or less force-free state.

[0087] When the temperature of the protected device, and thus of the switch 100, now rises to or above the switching temperature of the bimetallic element 12, the bimetallic element 12 snaps from its cold state shown in Fig. 5 to its hot state shown in Fig. 6. During this snapping action, the bimetallic element 12, supported at its outer edge 36 on a support surface 34 provided on at least one retaining claw 18, presses upwards with its inner edge 48 the movable contact 16 together with the spring element 14. As a result, the spring element 14 simultaneously bends upwards with its centre, whereby the movable contact 16 is lifted from the fixed contact 72. The circuit is thus interrupted and therefore the switch 100 opens.

[0088] The switch 100 together with the device to be protected and thus the bimetallic element 12 cools down again and snaps back to its cold state when the bimetallic element 12 reaches a reset temperature, also called a switchback temperature, as shown for example in Figure 5. This allows a reversible switching behavior to be achieved.

[0089] Of course, it is also possible to prevent the switch 100 from being switched back after being snapped into the hot state by a corresponding locking device. A large number of such locking devices, particularly for one-time switches which should be prevented from switching back, are already known from the prior art.

[0090] 7 and 8 show a further embodiment of a switch 100 according to the invention, again in schematic cross-section in both a cold state (FIG. 7) and a hot state (FIG. 8).

[0091] The spacer ring 70' has a slightly different shape here. However, the main difference with respect to the embodiment shown in figures 5 and 6 is that the opposing contacts 72 are not constructed here as fixed contacts but are arranged on opposing spring elements 74, by means of which manufacturing tolerances are optimally compensated. On the other hand, the contact pressure can be increased in the closed state of the switch (see figure 7), since the opposing spring elements 74 oppose the spring element 14 and thus increase the force with which the two contacts 16, 72 are pressed together. However, the switching principle remains the same as that previously described with reference to the embodiment shown in figures 5 and 6.

[0092] It is understood that various further modifications can be made to both the switching mechanism 10 itself and to the switch housing 62 without departing from the scope of the invention. Moreover, the shape of the at least one retention claw shown in this case can be varied almost freely, which is why the term "retention claw" in this case should be interpreted broadly. Functionally, the at least one retention claw 18 serves as a holder for the bimetal element 12, the latter being able to support it at its edge 36, especially in high temperature conditions of the switching mechanism 10.

Claims

1. A temperature dependent switching mechanism (10) for a temperature dependent switch (100), comprising: A bimetal element (12); A spring element (14); a conductive contact (16) provided on or fixed to the spring element (14); at least one retaining claw (18) provided on or fixed to the spring element (14) and having a support surface (34); Here, the bimetallic element (12) is configured to snap from a low temperature configuration to a high temperature configuration upon exceeding a response temperature, and the bimetallic element (12) is supported on a support surface (34) in its high temperature configuration.

2. 2. The temperature dependent switching mechanism (10) of claim 1, wherein the bimetallic element (12), the spring element (14) and the contact (16) form a switching mechanism unit that is restrainingly held together.

3. 2. The temperature dependent switching mechanism (10) of claim 1, wherein the bimetal element (12) is constrained and held at the contact portion (16) and / or at the spring element (14) by the at least one retention claw (18).

4. 2. The temperature dependent switching mechanism (10) of claim 1, wherein the at least one retention pawl (18) projects in one direction from a first side (30) of the spring element (14) opposite the bimetal element (12).

5. 5. The temperature dependent switching mechanism (10) of 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 the support surface (34) is disposed transversely to the first direction (32) and faces the spring element (14).

6. The temperature dependent switching mechanism (10) of claim 1 , wherein the at least one retention pawl (18) comprises at least two retention pawls (18).

7. 2. The temperature dependent switching mechanism (10) of claim 1, wherein the at least one retention claw (18) is a single retention claw (18) extending along at least a majority of the circumference of the spring element (14) or along the entire circumference of the spring element (14).

8. 2. The temperature dependent switching mechanism (10) of claim 1, wherein the at least one retention pawl (18) is integrally connected to the spring element (14) or secured to the spring element (14) in a material-locking manner.

9. 2. The temperature dependent switching mechanism (10) of claim 1, wherein the spring element (14) has an outer edge (28), and at least one retention pawl (18) is spaced apart from the outer edge (28).

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

11. 2. The temperature dependent switching mechanism (10) of claim 1, wherein the spring element (14) together with the at least one retaining claw (18) forms an open housing in which the bimetal element (12) is disposed, the open housing being accessible from the outside, and at least partially surrounding the bimetal element (12) from a first side (38), a second side opposite the first side (38), and a circumferential side (42) extending transversely to the first and second sides (38, 40).

12. 12. The temperature dependent switching mechanism (10) of claim 11, wherein the open housing formed by the spring element (14) together with the at least one retaining pawl (18) includes an opening (44) on the second side (40), the inner diameter of the opening (44) being smaller than the outer diameter of the bimetal element (12) measured parallel thereto.

13. 2. The temperature dependent switching mechanism (10) of claim 1, wherein the switching mechanism (10) is rotationally symmetric about a central axis (60) and the bimetallic element (12) is provided with a central opening (20) through which the contact portion (16) projects.

14. A temperature dependent switch (100) comprising a temperature dependent switching mechanism according to any one of claims 1 to 13.

15. 15. The temperature dependent switch (100) of claim 14, wherein the switch (100) includes a switch housing (62) in which the temperature dependent switching mechanism (10) is disposed, the switch housing including a lower portion (64) and a cover portion, and the spring element (14) is clamped between the lower portion (64) and the cover portion (66).

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