Temperature-dependent switch

Abstract

To simplify the assembly process and enable adaptation to variable contact resistance of a switching mechanism.SOLUTION: A temperature-dependent switch includes: a switch housing having a lower part and a cover part closing the lower part; a contact carrier element which is arranged in the switch housing and includes a contact surface, at least a part of the contact carrier element being fixed in a predetermined position by an interaction of the lower part and the cover part; and a switching mechanism which is arranged in the switch housing and includes a movable contact part that interacts with the contact surface arranged at the contact carrier element, the switching mechanism being configured to switch, in a temperature-dependent manner, between a low-temperature state where the switching mechanism presses the movable contact part against a contact surface to establish an electrical connection between first and second electrical terminals of the switch and a high-temperature state where the switching mechanism keeps the movable contact part spaced apart from the contact surface to interrupt the electrical connection between the first and second electrical terminals.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] A large number of temperature-dependent switches are already known in principle. Exemplary temperature-dependent switches are disclosed in DE 10 2018 100 890 A1, DE 10 2009 030 353 A1, DE 197 27 383 A1 and DE 197 27 197 A1.

[0003] Such temperature-dependent switches are primarily used in a known manner to monitor the temperature of a device: for this purpose, the switch is brought into thermal contact with the device to be protected, for example via one of its outer surfaces, so that the temperature of the protected device affects the temperature of a 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 German Patent 10 2018 100 890 the switching mechanism is arranged in a switch housing. The switch housing is a closed housing, in which the switching mechanism is sealed against the outside. The switch housing is formed in two parts. The switch housing comprises a lower part which is closed by a cover part. The cover part is fixed to the lower part. For this purpose the lower part is provided with a raised, circumferential edge and the free upper edge is bent or flanged onto the cover part.

[0006] The temperature dependent switching mechanism disposed within the switch housing comprises a spring element having a fixed movable contact and a bimetallic element interacting with the movable contact, the spring element pressing the movable contact against a fixed opposing contact disposed inside the switch housing on the cover part, the outer edge of the spring element configured as a snap-action spring disc is supported on the bottom of the switch housing such that current flows from the bottom through the snap-action spring disc and the movable contact to the fixed opposing contact and from there to the cover part.

[0007] The temperature-dependent bimetallic element in the switch disclosed in DE 10 2018 100 890 has a disk-shaped configuration and is often called a bimetallic snap-action disk, which is essentially responsible for the temperature-dependent switching behavior of the switching mechanism. This bimetallic element is usually configured as a multi-layer 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 material-locked or positive-locked and is achieved, for example, by rolling.

[0008] Such a bimetallic element has a first stable geometric configuration (low temperature configuration) below the response temperature of the bimetallic element and a second stable geometric configuration (high temperature configuration) above the response temperature of the bimetallic element, and the bimetallic element snaps from its low temperature configuration to its high temperature configuration in a temperature dependent manner in a hysteretic manner.

[0009] Thus, if the temperature of the bimetallic element rises above its response temperature as a result of a temperature increase in the device being 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 equipment to be protected so that it does not heat up any further.

[0010] Unless a reset lock is provided, the bimetallic element will snap back to its low temperature configuration, with the result that the switch will be 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.

[0011] 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 even 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.

[0012] For such a temperature-dependent switch to function properly, it is very important that the individual components of the temperature-dependent switching mechanism and the switch housing are very accurately matched to one another. In particular in this respect, it is important that the level inside the switch housing is very accurately matched to the level of the switching mechanism in the cold state, so that, for example, the contact pressure between the moving contact and the fixed opposing contact is correctly set. This also affects the contact resistance that occurs during the transition between the individual components of the switching mechanism and therefore also the performance of the switch.

[0013] For these reasons, the individual components of such temperature-dependent switches must be manufactured to very tight tolerances and must be dimensionally matched very accurately to one another. Thus, a very accurate preliminary check of the individual switch components is necessary. In some cases, it may be necessary to manually rework the individual components or even to manually select the appropriate components depending on the manufacturing tolerances in order to comply with the overall tolerances. This makes the automated assembly of such temperature-dependent switches more difficult.

[0014] In the switch disclosed in German Patent 10 2018 100 890, the level of the internal space of the switch housing is determined in particular by using spacer rings, which are arranged inside the switch housing between the lower part and the cover part and keep these two parts at a constant distance. By using spacer rings of different heights, the level of the interior of the housing, and therefore the contact pressure, can be correspondingly adjusted according to customer requirements. This can also be used to compensate for manufacturing tolerances of the components of the switching mechanism. However, the level of the spacer rings usually has to be adjusted manually to the manufacturing tolerances of the components of the switching mechanism.

[0015] Thus, there is still room for further improvement, in particular to improve the manufacturability of the switch, simplify its assembly, and achieve a higher degree of automation. Summary of the Invention [Problem to be solved by the invention]

[0016] It is therefore an object of the present invention to provide a temperature-dependent switch which is further improved in particular in the above-mentioned respects, in particular which is intended to simplify the assembly process and allow variable adaptation to specific customer requirements, for example with regard to the setting of the contact resistance between the components of the switching mechanism. [Means for solving the problem]

[0017] According to the invention, this object is solved by a temperature dependent switch comprising the following components: a switch housing having a lower portion and a cover portion for closing the lower portion; a contact carrier element disposed within the switch housing, the contact carrier element having a contact surface and fixed in place at least in part by interaction of the lower portion and the cover portion; A temperature dependent switching mechanism having a movable contact portion disposed within a switch housing and interacting with a contact surface disposed on a contact carrier element, the temperature dependent switching mechanism being configured to switch between a low temperature state and a high temperature state in dependence on temperature, the temperature dependent switching mechanism pressing the movable contact portion into contact with the contact surface to establish an electrical connection between a first electrical terminal of the switch and a second electrical terminal of the switch in the low temperature state and keeping the movable contact portion away from the contact surface to interrupt the electrical connection between the first electrical terminal and the second electrical terminal in the high temperature state.

[0018] In the switch according to the invention, the fixed contact surfaces (herein called "contact surfaces") which interact with the movable contacts in the cold state of the switching mechanism, unlike most switches known up to now, are not arranged on the cover part, but on a separate contact carrier element which is arranged in the switch housing and fixed in place by the interaction of the lower part with the cover part.

[0019] "Fixed in position by interaction of the lower part and the cover part" means that the contact carrier element is fixed in position by interaction of the two switch housing components (cover part and lower part). The contact carrier element is therefore fixed in position only when the two switch housing components are connected to each other. The two switch housing components then only apply a force to the contact carrier element to fix it in position.

[0020] The additional contact carrier element provided according to the invention has various advantages. On the one hand, the mechanical stability of the switch structure is improved by the provision of the additional contact carrier element. On the other hand, the contact pressure with which the movable contacts are pressed against the contact surfaces in the cold state of the switching mechanism can be very easily determined or adjusted by a correspondingly adjustable shaping of the contact carrier element. In particular, it is advantageous if an adjustment of this type of contact pressure can be made almost independently of the shape of the lower and cover parts of the switch housing. By selecting contact carrier elements of different shapes, for example according to customer requirements, different contact pressures and therefore also different contact resistances can be realized in the same switch housing without having to change the shape of the lower and cover parts of the switch housing.

[0021] Furthermore, the contact carrier elements can relatively easily compensate for manufacturing tolerances on the components of the switching mechanism, for example by making the contact carrier elements conformal or elastic or resilient, so that the preliminary check tests mentioned at the beginning for the manufacturing tolerances of the individual housing components or components of the switching mechanism can be omitted or at least minimized.

[0022] The provision of the contact carrier element provides the additional advantage that one or both external terminals can be welded to the cover part, which would not be possible or only possible with difficulty without the contact carrier element, since the normally fixed opposing contact part would be thermally detached from the cover part, but this problem is also solved at the same time, since the contact surfaces are now arranged on the contact carrier element and not on the cover part.

[0023] The switch according to the invention can be produced both manually and fully automatically, the latter being simplified by the contact carrier elements for the reasons mentioned above.

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

[0025] In one embodiment, the switching mechanism is (i) disposed between the contact carrier element and the lower portion, and the contact carrier element is conductively connected to the cover portion, or (ii) disposed between the contact carrier element and the cover portion, and the contact carrier element is conductively connected to the lower portion.

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

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

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

[0029] In a further refinement, at least one portion of the contact carrier element fixed in place by interaction of the lower portion and the cover portion comprises an outer edge of the contact carrier element, and a central region of the contact carrier element is spaced from both the lower portion and the cover portion.

[0030] In other words, the contact carrier element is preferably fixed in its position at the edge by the interaction of the lower part and the cover part. Particularly preferably, at least one part of the contact carrier element comprises the radially outer edge of the contact carrier element. This has the advantage that the edge side of the contact carrier element is implemented as space-saving as possible, while the central region of the contact carrier element is freely accessible for the switching mechanism and can be formed relatively freely in response to the desired customer specifications in terms of contact pressure and contact resistance. Due to the fact that the central region of the contact carrier element is spaced apart from both the lower part and the cover part, this central region is flexible or elastic, which ensures optimal tolerance compensation.

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

[0032] Such a clamping arrangement between the lower part and the cover part is a particularly easy way to fix the position of the contact carrier element. In this way, the contact carrier element can be easily inserted in the desired position inside the switch housing during assembly of the switch, so that the switch housing can be closed by fixing the cover part to the lower part or vice versa. No additional efforts are required by the contact carrier element during the assembly process. On the contrary, this assembly effort can be reduced due to the above-mentioned advantages that the contact carrier element provides.

[0033] "Indirectly clamped" means in this case that the contact carrier element is clamped together by the cover part and the lower part, but does not necessarily have to directly contact these two switch housing components. Furthermore, a housing component or element can be located between the cover part and the lower part.

[0034] In a refinement, the temperature dependent switching mechanism comprises a first spring element interacting with the moveable contact and a bimetallic element interacting with the moveable contact.

[0035] The first spring element is preferably configured as a temperature-independent circular disc-shaped spring disk, the bimetal element is preferably configured as a temperature-dependent circular disc-shaped bimetal disk, and the contact element is preferably circular in plan view when viewed from above.

[0036] In a refinement, the contact carrier element is configured in a lid-like manner and has a smaller wall thickness than the cover part.

[0037] Thus, according to this refinement, the contact carrier element is arranged inside the switch housing between the cover part and the lower part and acts as a kind of sub-cover on which the (fixed) contact surfaces are arranged. The thinner wall thickness compared to the cover part has the advantage that the contact carrier element can be configured to be much more flexible or elastic than the cover part. In other words, the cover part still serves as the main protective and mechanically stable carrier, whereas the contact carrier element may be relatively thin-walled to be variably adaptable to the shape of the switching mechanism.

[0038] In a further refinement, the switching mechanism comprises the above-mentioned first spring element which exerts a first spring force in a cold state of the switching mechanism, with which the movable contact is pressed against the contact surface.

[0039] The first spring element is preferably a snap-action spring disk as would normally be inserted into the switching mechanism of such a temperature dependent switch, and is preferably used as the current carrying component in the cold state of the switching mechanism.

[0040] As a further refinement, the contact carrier element comprises a second spring element which exerts a second spring force in a cold state of the switching mechanism, with which the contact surface is pressed against the movable contact portion.

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

[0042] According to this refinement, the contact carrier element can comprise a second spring element or can be completely formed by the second spring element. In other words, the contact carrier element can be configured entirely as a (second) spring element. Regardless of whether the contact carrier element comprises a second spring element or is entirely formed by the second spring element, such a resilient configuration of the contact carrier element has the advantage that the contact pressure with which the movable contacts are pressed against the contact surface can be significantly increased in the cold state of the switching mechanism.

[0043] In contrast to conventional temperature-dependent switches, in a switch according to this configuration, two oppositely acting springs are used, both of which ensure that in the cold state of the switch, the movable contact is pressed against a contact surface arranged on the contact carrier element. This increased contact pressure makes it possible to reduce the contact resistance between the movable contact and the contact surface, thereby increasing the performance of the switch.

[0044] The suspended or resilient configuration of the contact carrier elements also improves the already mentioned compensation of mechanical tolerances achieved by the contact carrier elements.

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

[0046] This has the advantage that the contact pressure is mainly caused by the second spring element. This in turn is advantageous in that the opening force required, in particular to open the switching mechanism, i.e. to move the switching mechanism from its cold state to its hot state, can be lower than usual. To open the switching mechanism, the first spring force caused by the first spring element must be overcome. This is usually done by a bimetallic element belonging to the switching mechanism.

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

[0048] This has the advantage that when the switching mechanism opens, i.e. when passing from the cold to the hot state, the second spring element does not yield too much and does not follow the movement of the moveable contact, therefore, despite the two spring elements acting against each other, an effective opening of the switching mechanism can be achieved when the response temperature is reached.

[0049] Preferably, in a hot condition of the switching mechanism, the bimetallic element exerts an opening force on the moveable contact that opposes and is greater than the first spring force.

[0050] Thus, upon reaching the response temperature, the bimetallic element snaps into its high temperature configuration, thereby lifting the movable contact off of the contact surface arranged on the contact carrier element, against the spring force exerted by the first spring element.

[0051] In a further refinement, the first electrical terminal of the switch is arranged on the outside of the cover part and the second electrical terminal of the switch is arranged on the outside of the lower part.

[0052] This ensures that the temperature dependent switch can be easily electrically connected.

[0053] In a further refinement, the switch further comprises an insulating foil arranged between the lower part and the contact carrier element.

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

[0055] Preferably, the contact carrier element and the lower portion each consist of an electrically conductive material.

[0056] In a further refinement, the lower part is provided with a free upper edge that is flanged or bent over the cover part.

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

[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 switch according to a first embodiment, the switch being in its cold state; [Diagram 2] 2 is a schematic cross-sectional view of the temperature dependent switch shown in FIG. 1, the switch being in its hot state; [Diagram 3] 4 is a schematic cross-sectional view of a temperature dependent switch according to a second embodiment, the switch being in its cold state; FIG. [Figure 4] 4 is a schematic cross-sectional view of a temperature dependent switch according to a third embodiment, the switch being in its cold state; FIG. [Diagram 5] FIG. 11 is a schematic cross-sectional view of a temperature dependent switch according to a fourth embodiment, the switch being in its cold state; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0060] 1 to 5 show four different embodiments of a switch according to the invention, each in schematic cross-section, in each case the switch being generally designated by the numeral 10.

[0061] Regarding the switch according to the first embodiment, FIG. 1 shows the switch 10 in a low temperature state, and FIG. 2 shows the switch 10 in a high temperature state.

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

[0063] The lower part 16 as well as the cover part 18 are made of an electrically conductive material, preferably metal. In the embodiment shown, the lower part 16 is a housing made of deep-drawn steel, which provides a relatively high pressure resistance. Between the lower part 16 and the cover part 18 an insulating foil 22 is arranged, which serves to electrically insulate the two switch housing components 16, 18.

[0064] The upper edge 20 of the lower part 16 is bent radially inwardly to press the cover part 18 in the direction of a circumferential shoulder 24 on the lower part 16, which thus completely closes the lower part 16. In addition to providing electrical insulation, the insulating foil 22 also provides a sufficient mechanical seal between the lower part 16 and the cover part 18, so that the interior of the switch housing 12 is sealed from the outside. This prevents the ingress of liquids and impurities from the outside into the interior of the housing.

[0065] The switching mechanism 14 arranged inside the switch housing 12 comprises a temperature-independent spring element 26 and a temperature-dependent bimetallic element 28. The spring element 26 is preferably configured as a spring disk in the shape of a circular disk. Particularly preferably, the spring element 26 is designed as a bistable spring disk consisting of two temperature-independent stable geometric configurations. The first geometric configuration is shown in FIG. 1. The second geometric configuration is shown in FIG. 2.

[0066] The temperature-dependent bimetallic element 28 is preferably configured as a bimetallic disc, which comprises two temperature-dependent configurations: a geometrically cold configuration (see FIG. 1) and a geometrically hot configuration (see FIG. 2).

[0067] 1, the spring element 26 rests with its edge 30 on a contact surface 34 that projects upwardly from a lower inner bottom surface 32. The inner bottom surface 32 is essentially concave and is slightly elevated relative to a central region of the inner bottom surface 32 at the point where the edge 30 of the spring element rests in the cold state of the switching mechanism 14. An edge 36 of the bimetal element 28 rests on the spring element 26 in the cold state of the switching mechanism 14 shown in FIG.

[0068] The spring element 26 has a central portion 38 fixed to a movable contact 40 of the switching mechanism 14. The movable contact 40 is preferably connected to the spring element 26 in a material-locking and / or positive-locking manner. For example, the contact 40 is welded or soldered to the spring element 26.

[0069] Alternatively, the bimetallic element 28 may be fixed at its center 42 to the movable contact portion 40. However, the bimetallic element 28 may also be loosely connected to the contact portion 40, with a centrally located opening of the bimetallic element 28 sliding over the contact portion 40 and an inner edge surrounding the center or opening resting from above on a support shoulder 44 provided on the contact portion 40.

[0070] 1, the movable contact portion 40 interacts with a contact surface 46 provided on the underside of the contact portion 48. In this cold state of the switching mechanism 14, the spring element 26 presses the movable contact portion 40 against the contact surface 46 of the contact portion 48 from below.

[0071] The contact parts 48 are arranged on a contact carrier element 50 which in the embodiment shown in Figures 1 and 2 has a lid-like configuration. This lid-like contact carrier element 50 also consists of an electrically conductive material and preferably has a thinner wall thickness than the cover part 18 of the switch housing 12 arranged thereon.

[0072] In the region of its outer edge 52, the contact carrier element 50 rests on a shoulder 24 provided on the inside of the lower part 16, with the insulating foil 22 interposed therebetween. On its upper side, the contact carrier element 16 rests in the region of its outer edge 52 on the bottom side of the cover part 18. The outer edge 52 of the contact carrier element 50 is thus fixed in place by the interaction of the lower part 16 and the upper part 18 and is clamped between them.

[0073] The central region 54 of the contact carrier element 50 is spaced from both the lower portion 16 and the upper portion 18 within the switch housing 12. As such, the central region 54 of the contact carrier element 50 is limited in movement within the switch housing 12 in response to the resiliency of the contact carrier element 50.

[0074] In the first embodiment shown in Figures 1 and 2, the contact carrier element 50 forms a kind of lower cover, which is arranged between the cover part 18 and the switching mechanism 14. In the cold state of the switch 10 (see Figure 1), the movable contact part 40 of the switching mechanism 14 is supported on the contact carrier element 50. In this switching position of the switching mechanism 14, the contact carrier element 50 accordingly exerts a force on the movable contact part 40, which is opposite to the force exerted on the movable contact part 40 by the spring element 26.

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

[0076] In the cold state shown in FIG. 1 , the switching mechanism 14 establishes a conductive connection between the first electrical terminal 56 and the second electrical terminal 58. In this embodiment, the top side of the cover part 18 serves as the first electrical terminal 56. In this embodiment, a welded connection ring soldered or welded to the lower part 16 of the switch housing 12 serves as the second electrical terminal 58. Thus, in the cold state of the switch 10, electrical current flows from the first electrical terminal 56 through the cover part 18 to the contact carrier element 50, from there to the contact part 48 to the contact part 40, through the spring element 26 to the lower part 16, and finally to the second electrical terminal 58 (or vice versa).

[0077] Starting from the situation shown in Fig. 1, if the temperature of the device monitored by the switch 10, and thus the temperature of the switch 10 and the switching mechanism 14 used therein, rises above the response temperature of the bimetallic element 28, the bimetallic element 28 snaps (moves suddenly) from its cold configuration shown in Fig. 1 to its hot configuration shown in Fig. 2. The upper side of the bimetallic element 28 thereby snaps from a convex curvature to a concave curvature. The bimetallic element 28 is then supported from below with its outer edge 36 resting on the contact carrier element 50, with the insulating foil 22 between them. At the same time, the bimetallic element 28 presses the movable contact portion 40 with its central portion 42 downwards, lifting the movable contact portion 40 from the contact surface 46. During this switching movement, the bimetallic element 28 exerts a force that acts against the force exerted by the spring element 26 on the contact portion 40 in the cold state. As a result, the spring element 26 also snaps from its first convex shape shown in the upper part of FIG. 1 to its upper concave shape shown in FIG.

[0078] This blocks the flow of current through switch 10. Switch 10 is therefore open.

[0079] Figure 3 shows a further embodiment of the switch 10 according to the invention. The second embodiment shown in Figure 3 differs from the first embodiment shown in Figures 1 and 2 in that, in particular, the contact surface 46 is arranged directly on the contact carrier element 50, i.e. no additional contacts 48 are attached to the contact carrier element 50. The contact carrier element 50 is therefore somewhat flatter here than in the first embodiment. In particular, a central region 54 of the contact carrier element 50 is therefore relatively far away from the bottom surface of the cover part 18.

[0080] 4 shows a third embodiment of a switch 10 according to the invention, in which the contact carrier element 50 comprises a spring element 60. This spring element 60 is preferably arranged in a central region 54 of the contact carrier element 50, a contact part 58 on which the contact surface 46 is provided is arranged. In principle, however, it is also possible for the contact carrier element 50 to be configured as the spring element 60 in its entirety.

[0081] In the following, spring element 60 will be referred to as the "second spring element" to better distinguish it from spring element 26. In the following, spring element 26 will be referred to as the "first spring element".

[0082] The contact carrier element 50 is configured as a kind of opposing spring and opposes the spring element 26 in the cold state of the switching mechanism 14. This allows a larger contact force with which the movable contact 40 is pressed against the contact surface 46 in the cold state of the switching mechanism 14. This has the advantage that the contact resistance can be reduced and thus the performance of the switch 10 can be increased. Furthermore, the second spring element 60 allows for further tolerance compensation.

[0083] The spring force exerted by the first spring element 26 is opposite to the spring force exerted by the second spring element 60. The spring force exerted by the second spring element 60 on the moveable contact portion 40 via the contact portion 48 is preferably greater than the spring force exerted by the first spring element 26 on the contact portion 40. However, the second spring element 60 preferably has a smaller amount of spring travel than the first spring element 26.

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

[0085] 1 to 4, the switching mechanism 14 is turned upside down by 180°. In the cold state of the switch 10, the first spring element 26 bears with its outer edge 30 on the underside of the cover part 18 and presses the contact part 40 upwards against a contact surface 46 provided on the contact carrier element 50. In this switching state, the outer edge 36 of the bimetallic element 28 hangs freely below it.

[0086] However, in the hot condition of switch 10 shown in FIG. 5 (hot condition not separately shown), bimetallic element 28 is supported at its outer edge 36 on spacer ring 62, thereby lifting movable contact 40 off contact surface 46, such that switch 10 is open.

[0087] In the fourth embodiment, the contact portion 40 is formed in two parts. Both the spring element 26 and the bimetal element 28 are restrained and held at their respective central portions 38, 42 on the contact portion 40 configured as a rivet.

[0088] It will be understood that various further modifications of the illustrated embodiment are possible without departing from the scope of the invention.

Claims

1. A temperature dependent switch (10), comprising: a switch housing (12) having a lower portion (16) and a cover portion (18) that closes the lower portion (16); a contact carrier element (50) disposed within the switch housing (12), the contact carrier element (50) having a contact surface (46) and fixed in place at least in part by interaction of the lower portion (16) and the cover portion (18); 1. A temperature dependent switch comprising: a switching mechanism (14) disposed within a switch housing (12) and having a movable contact (40) interacting with a contact surface (46) disposed on a contact carrier element (50), the switching mechanism (14) being configured to switch between a low temperature state and a high temperature state in dependence on temperature, the switching mechanism (14) pressing the movable contact (40) into contact with the contact surface (46) to establish an electrical connection between a first electrical terminal (56) of the switch (10) and a second electrical terminal (58) of the switch (10) in a low temperature state and maintaining the movable contact (40) away from the contact surface (46) to interrupt the electrical connection between the first electrical terminal (56) and the second electrical terminal (58) in a high temperature state.

2. (i) the switching mechanism (14) is disposed between the contact carrier element (50) and the lower portion (16), the contact carrier element (50) being conductively connected to the cover portion (18); or (ii) the temperature dependent switch of claim 1, wherein the switching mechanism (14) is disposed between a contact carrier element (50) and the cover portion (18), the contact carrier element (50) being conductively connected to the lower portion (16).

3. 2. The temperature dependent switch of claim 1, wherein at least one portion of the contact carrier element (50) that is fixed in place by interaction of the lower portion (16) and the cover portion (18) comprises an outer edge (52) of the contact carrier element (50), and a central region (54) of the contact carrier element (50) is spaced from both the lower portion (16) and the cover portion (18).

4. 2. The temperature dependent switch of claim 1, wherein the contact carrier element (50) is clamped directly or indirectly between the lower portion (16) and the cover portion (18).

5. 2. The temperature-dependent switch according to claim 1, wherein the contact carrier element (50) is configured in the form of a lid and has a smaller wall thickness than the cover part (18).

6. 2. The temperature dependent switch of claim 1, wherein the switching mechanism (14) includes a first spring element (26) that exerts a first spring force urging the movable contact (40) against the contact surface (46) in a cold state of the switching mechanism (14).

7. 7. The temperature dependent switch of claim 6, wherein the contact carrier element (50) comprises a second spring element (60) which exerts a second spring force urging the contact surface (46) against the moveable contact portion (40) in a cold state of the switching mechanism (14).

8. 8. The temperature dependent switch of claim 7, wherein said first spring force opposes said second spring force.

9. The temperature dependent switch of claim 8 , wherein the second spring force is greater than the first spring force.

10. 8. The temperature dependent switch of claim 7, wherein said first spring element (26) has a greater spring travel than said second spring element (60).

11. The temperature dependent switch of claim 1, wherein the switching mechanism (14) includes a bimetallic element (28).

12. 12. The temperature dependent switch of claim 11, wherein the bimetallic element (28) exerts an opening force on the movable contact (40) during a high temperature condition of the switching mechanism (14), the opening force being opposite and greater than a first spring force.

13. 2. The temperature dependent switch of claim 1, wherein the first electrical terminal (56) is disposed on an exterior side of the cover portion (18) and the second electrical terminal (58) is disposed on an exterior side of the lower portion (16).

14. 2. The temperature dependent switch of claim 1, wherein the switch (10) further comprises an insulating foil (22) disposed between the lower portion (16) and the contact carrier element (50).

15. 2. The temperature dependent switch of claim 1, wherein the lower portion (16) has a free upper edge (20) that is flanged or bent over the cover portion (18).

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