TEMPERATURE-DEPENDENT SWITCHING MECHANISM AND TEMPERATURE-DEPENDENT SWITCH

Abstract

A temperature-dependent switching mechanism for a temperature-dependent switch, having a temperature-dependent bimetal snap-action disc, a temperature independent snap-action spring disc, an electrically conductive contact member to which the bimetal snap-action disc and the snap-action spring disc are captively held, so that the bimetal snap-action disc, the snap-action spring disc and the contact member form a switching mechanism unit captively held together, and a switching mechanism housing having a base body. The base body of the switching mechanism housing surrounds the switching mechanism unit from a first housing side, a second housing side, and a housing peripheral side. The switching mechanism housing comprises a first opening in the base body on the first housing side, through which the contact member is accessible from outside the switching mechanism housing, and a second opening in the base body on the second housing side, through which the contact member is accessible from outside the switching mechanism housing.

Claims

1. A temperature-dependent switching mechanism for a temperature-dependent switch, having: a temperature-dependent bimetal snap-action disc; a temperature-independent snap-action spring disc; an electrically conductive contact member to which the bimetal snap-action disc and the snap-action spring disc are captively held, so that the bimetal snap-action disc, the snap-action spring disc, and the contact member form a switching mechanism unit captively held together; and a switching mechanism housing having a base body, in which the switching mechanism unit is arranged and which captively holds the switching mechanism unit; wherein the base body of the switching mechanism housing surrounds the switching mechanism unit from a first housing side, a second housing side opposite the first housing side, and a housing peripheral side extending between and transverse to the first and second housing sides, and wherein the switching mechanism housing is configured as an at least partially open housing and comprises a first opening in the base body on the first housing side, through which the contact member is accessible from outside the switching mechanism housing, and a second opening in the base body on the second housing side, through which the contact member is accessible from outside the switching mechanism housing.

2. The temperature-dependent switching mechanism according to claim 1, wherein the contact member permanently projects out of the switching mechanism housing through the first opening or is movable together with the bimetal snap-action disc and the snap-action spring disc within the switching mechanism housing in such a way that the contact member projects out of the switching mechanism housing through the first opening upon a corresponding movement.

3. The temperature-dependent switching mechanism according to claim 1, wherein the bimetal snap-action disc is configured to snap from a low-temperature configuration into a high-temperature configuration upon exceeding a response temperature, and wherein the contact member projects out of the switching mechanism housing through the first opening when the bimetal snap-action disc is in its low-temperature configuration.

4. The temperature-dependent switching mechanism according to claim 3, wherein, when the bimetal snap-action disc is in its high-temperature configuration, the contact member is arranged in the second opening or projects out of the switching mechanism housing through the second opening.

5. The temperature-dependent switching mechanism according to claim 1, wherein an inner diameter of the first opening and an inner diameter of the second opening are each smaller than an outer diameter of the bimetal snap-action disc.

6. The temperature-dependent switching mechanism according to claim 5, wherein the inner diameter of the second opening is smaller than the inner diameter of the first opening.

7. The temperature-dependent switching mechanism according to claim 1, wherein an inner diameter of the first opening and an inner diameter of the second opening are each smaller than an outer diameter of the snap-action spring disc.

8. The temperature-dependent switching mechanism according to claim 7, wherein the inner diameter of the second opening is smaller than the inner diameter of the first opening.

9. The temperature-dependent switching mechanism according to claim 1, wherein the second opening comprises a hole that is arranged centrally on the second housing side of the switching mechanism housing.

10. The temperature-dependent switching mechanism according to claim 1, wherein the switching mechanism housing comprises a side wall forming the housing peripheral side, and wherein an upper portion of the side wall is bent and forms the first housing side.

11. The temperature-dependent switching mechanism according to claim 10, wherein the upper portion of the side wall comprises a plurality of separate, circumferentially distributed, bent segments forming the first housing side.

12. The temperature-dependent switching mechanism according to claim 10, wherein the bimetal snap-action disc is configured to snap from a geometrically stable low temperature configuration to a geometrically stable high temperature configuration upon exceeding a response temperature, and wherein the bimetal snap-action disc in its low temperature configuration is spaced from an inner surface of the upper portion of the side wall arranged inside the switching mechanism housing and in its high temperature configuration bears against the inner surface of the upper portion of the side wall.

13. The temperature-dependent switching mechanism according to claim 1, wherein the switching mechanism housing is formed in one piece.

14. The temperature-dependent switching mechanism according to claim 1, wherein the base body of the switching mechanism housing comprises an electrically conductive material.

15. The temperature-dependent switching mechanism according to claim 1, wherein the switching mechanism housing is rotationally symmetrical about a central axis.

16. A temperature-dependent switch, comprising: a temperature-dependent switching mechanism; and a switch housing surrounding the switching mechanism and comprising a first contact and a second contact, wherein the temperature-dependent switching mechanism comprises: a temperature-dependent bimetal snap-action disc; a temperature-independent snap-action spring disc; an electrically conductive contact member to which the bimetal snap-action disc and the snap-action spring disc are captively held, so that the bimetal snap-action disc, the snap-action spring disc, and the contact member form a switching mechanism unit captively held together; and a switching mechanism housing having a base body, in which the switching mechanism unit is arranged and which captively holds the switching mechanism unit; wherein the base body of the switching mechanism housing surrounds the switching mechanism unit from a first housing side, a second housing side opposite the first housing side, and a housing peripheral side extending between and transverse to the first and second housing sides, wherein the switching mechanism housing is configured as an at least partially open housing and comprises a first opening in the base body on the first housing side, through which the contact member is accessible from outside the switching mechanism housing, and a second opening in the base body on the second housing side, through which the contact member is accessible from outside the switching mechanism housing, and wherein the temperature-dependent switching mechanism is configured to establish an electrical connection between the first contact and the second contact below a response temperature of the bimetal snap-action disc and to interrupt the electrical connection upon exceeding the response temperature.

17. The temperature-dependent switch according to claim 16, wherein the switching mechanism is configured to press the contact member through the first opening against the first contact below the response temperature of the bimetal snap-action disc.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0082] FIG. 1 is a schematic sectional view of the temperature-dependent switching mechanism according to an embodiment;

[0083] FIG. 2 is a top view from above of the switching mechanism shown in FIG. 1;

[0084] FIG. 3 is a schematic sectional view of the temperature-dependent switch according to an embodiment, wherein the switch is in its low-temperature position; and

[0085] FIG. 4 is a schematic sectional view of the temperature-dependent switch shown in FIG. 3, wherein the switch is in its high-temperature position.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0086] FIG. 1 shows an embodiment of the switching mechanism in a schematic sectional view. The switching mechanism is denoted in its entirety by reference numeral 10.

[0087] The switching mechanism 10 is a temperature-dependent switching mechanism. It comprises a functional switching mechanism unit 12 and a switching mechanism housing 14 surrounding this switching mechanism unit 12. The switching mechanism housing 14 comprises a one-piece base body which surrounds the switching mechanism unit 12 from all six spatial directions, at least partially in each case. As is explained in detail in the following, the switching mechanism housing 14 or the base body forming the switching mechanism housing is configured as a partially open housing, so that the switching mechanism unit 12 is accessible from at least two spatial directions, preferably from only two spatial directions, from outside the switching mechanism housing 14.

[0088] Due to the fact that the switching mechanism housing 14 at least partially surrounds the switching mechanism unit 12 from all six spatial directions, the switching mechanism unit 12 is captively held in the switching mechanism housing 14. As long as the switching mechanism 10 is not inserted into a temperature-dependent switch, there is preferably some clearance between the switching mechanism unit 12 and the switching mechanism housing 14. The switching mechanism unit 12 is movable within the switching mechanism housing 14 when the switching mechanism 10 is in the low temperature position.

[0089] The switching mechanism unit 12 is constructed in three parts. The switching mechanism unit 12 comprises a temperature-dependent bimetal snap-action disc 16, a temperature-independent snap-action spring disc 18 and a contact member 20. The bimetal snap-action disc 16 and the snap-action spring disc 18 are captively held on the contact member 20.

[0090] The switching mechanism unit 12 can thus be pre-produced as a semi-finished product and then inserted as a whole into the switching mechanism housing 14. The switching mechanism 10 together with the switching mechanism unit 12 and the switching mechanism housing 14 then also form a semi-finished product for a temperature-dependent switch produced therefrom later.

[0091] Since both the three components 16, 18, 20 of the switching mechanism unit 12 are captive to each other and the switching mechanism unit 12 is captively held in the switching mechanism housing 14, the switching mechanism 10 can be held in bulk storage until it is installed in a temperature-dependent switch. However, it should be noted that the components 16, 18, 20 of the switching mechanism unit 12 themselves do not necessarily have to be captively connected to each other, as this connection function is already ensured by the switching mechanism housing 14. The bimetal snap-action disc 16 and the snap-action spring disc 18 can therefore also be placed loosely on the contact member 20 as long as the three components 16, 18, 20 are held together by the switching mechanism housing 14. Even then, the switching mechanism 10 can be pre-produced and stored in bulk.

[0092] The switching mechanism housing 14 protects the fragile components of the switching mechanism unit 12, i.e. in particular the bimetal snap-action disc 16 and the snap-action spring disc 18, from damage during bulk storage. The insertion of the switching mechanism unit 12 into such a switching mechanism housing 14 also has the advantage that the switching mechanism 10 can be inserted a switching mechanism inlay in a very simple manner into a temperature-dependent switch to be manufactured. Due to this very simple handling of the switching mechanism, the assembly process of the temperature-dependent switch can be automated without more ado.

[0093] The one-piece base body forming switching mechanism housing 14 at least partially surrounds the switching mechanism unit 12 from a first housing side 22, a second housing side 24 opposite the first housing side 22, and a housing peripheral side 26 extending between and transverse to the first and second housing sides 22, 24, respectively. Preferably, the switching mechanism housing 14 completely surrounds the switching mechanism unit 12 from the housing peripheral side 26. Thus, the housing peripheral side 26 preferably forms a closed housing side of the switching mechanism housing 14. The first housing side 22 and the second housing side 24 are each partially open housing sides of the switching mechanism housing 14. In other words, the housing peripheral side 26 surrounds the switching mechanism unit 12 along the entire circumference, i.e. from a total of four mutually orthogonally aligned spatial directions. Furthermore, the switching mechanism housing 14 also completely surrounds the switching mechanism unit 12 from the two remaining spatial directions, which are orthogonal to the four spatial directions mentioned.

[0094] At the first housing side 22, the base body of the switching mechanism housing 14 comprises a first opening 28, through which the contact member 20 is accessible from outside the switching mechanism housing 14. At the second housing side 24, the base body of the switching mechanism housing 14 comprises a second opening 29, through which the contact member 20 is also accessible from outside the switching mechanism housing 14.

[0095] According to the embodiment shown in FIG. 1, the contact member 20 permanently projects outward through the first opening 28. However, depending on the design of the height of the switching mechanism housing 14, this does not necessarily have to be the case. In principle, it is sufficient if the contact member 20 is accessible from the outside through the first opening 28 and the switching mechanism unit 12 is movable within the switching mechanism housing 14 in such a way that the contact member 20 projects outward through the first opening 28 during a corresponding movement within the switching mechanism housing 14. This is preferably the case, in particular, when the switching mechanism 10 is in its low-temperature position shown in FIG. 1.

[0096] The second opening 29, on the other hand, is required in particular when the switching mechanism 10 is in its high-temperature position (see FIG. 4). This second opening 29 then offers the possibility of greater freedom of movement of the switching mechanism unit 12 within the switching mechanism housing 14, since the contact member can then also project out of the switching mechanism housing 14 through the second opening 29 in this position of the switching mechanism 10 or at least partially project into the second opening 29. Thus, the structure of the switching mechanism housing 14 with such a second opening 29 can be made flatter than without such a second opening 29.

[0097] An inner diameter d1 of the first opening 28 is smaller than an outer diameter D3 of the bimetal snap-action disc 16 and/or the snap-action spring disc 18 measured thereto. Similarly, an inner diameter d2 of the second opening 29 is smaller than the outer diameter D3 of the bimetal snap-action disc 16 and/or the snap-action spring disc 18. Thus, although the contact member 20 is accessible from the outside by the openings 28, 29 from opposite sides, the bimetal snap-action disc 16 and the snap-action spring disc 18 cannot detach from the switching mechanism housing 14.

[0098] The inner diameter d2 of the second opening 29 is smaller than the inner diameter d1 of the first opening 28. However, the inner diameter d2 of the second opening 29 should be larger than the outer diameter of the contact member 20.

[0099] The switching mechanism housing 14 is of one-piece design and consists of a base body made of an electrically conductive material, for example metal. The base body of switching mechanism housing 14 comprises a bottom wall 30 and a side wall 32 integrally connected to the bottom wall. The bottom wall 30 forms the second housing side 24 of the switching mechanism housing 14. The second opening 29 is preferably formed as a central hole, which is inserted centrally in the bottom wall 30. The side wall 32 forms the housing peripheral side 26 of the switching mechanism housing 14. A free upper portion 34 of the side wall 32 is bent in a direction towards a central axis 36, which forms the longitudinal axis of the contact member 20.

[0100] In principle, the upper portion can be bent along the entire circumference, so that the circumferential edge 38 of this bent upper portion 34 delimits the first opening 28 of the switching mechanism housing 14 in the radial direction along the entire circumference. However, in order to avoid the formation of folds, it is advantageous if the upper portion 34 of the side wall 32 comprises a plurality of separate bent segments 35 arranged distributed in the circumferential direction, as shown in the plan view in FIG. 2.

[0101] In the low-temperature position of the switching mechanism 10 shown in FIG. 1, the snap-action spring disc 18 bears with its outer edge against the switching mechanism housing 14. More specifically, the snap-action spring disc 18 bears with its outer edge on an inner side 40 of the bottom wall 30 facing the switching mechanism unit 12. In this position of the switching mechanism unit 10, the snap-action spring disc 18 carries the contact member 20. The bimetal snap-action disc 16, on the other hand, is in this position of the switching mechanism mounted in the switching mechanism housing 14 more or less free of forces.

[0102] The two snap-action discs 16, 18 are preferably circular disc-shaped and each comprises a centrally arranged through hole 42, 44. The through hole 42 arranged centrally in the bimetal snap-action disc 16 is referred to as the first through hole. The through hole 44 arranged in the snap-action spring disc 18 is referred to as the second through hole.

[0103] The two snap-action discs 16, 18 are slipped over the contact member 20 from opposite sides with their respective through hole 42, 44. The contact member 20 thus penetrates both snap-action discs 16, 18 at a central position.

[0104] The contact member 20 comprises a base body 46, which is preferably solid and made of an electrically conductive material. The base body 46 is passed through the two through holes 42, 44.

[0105] Approximately in the middle, i.e. at about half the height, the contact member 20 comprises a support shoulder 48 projecting radially from the base body 46. The two snap-action discs 16, 18 rest against this support shoulder 48 from opposite sides. The bimetal snap-action disc 16 is arranged on a first side of the support shoulder 48, which in FIGS. 1 and 2 forms the upper side of the support shoulder 48. The snap-action spring disc 18 is arranged on a second side of the support shoulder 48 opposite the first side, which second side forms the bottom side of the support shoulder 48 in FIGS. 1 and 2.

[0106] Further, locking elements 50, 52 are formed on the contact member 20, with the aid of which the two snap-action discs 16, 18 are held on the contact member 20. The two locking elements 50, 52 project radially from the base body 46 of the contact member 20. The first locking element 50 is arranged on the first side of the support shoulder 48. The second locking element 52 is arranged on the opposite second side of the support shoulder 48.

[0107] The bimetal snap-action disc 16 is arranged between the first locking element 50 and the support shoulder 48, and is held captive to the contact member 20 due to the radial projection of the first locking element 50 and the support shoulder 48 between the first locking element 50 and the support shoulder 48.

[0108] The snap-action spring disc 18 is arranged between the second locking element 52 and the support shoulder 48, and is held captive to the contact member 20 due to the radial projection of the second locking element 52 and the support shoulder 48 between the second locking element 52 and the support shoulder 48.

[0109] The contact member 20 is formed in one piece together with the support shoulder 48 and the two locking elements 50, 52. The support shoulder 48 and the two locking elements 50, 52 are therefore integral with the base body 46 of the contact member 20.

[0110] In the embodiment shown in FIG. 1, the two locking elements 50, 52 are each configured as a circumferential collar. The circumferential collar forming the first locking element 50 projects upward at an angle radially from the base body 46 of the contact member 20. The collar forming the second locking element 52 projects downward at an angle radially from the base body 46 of the contact member 20.

[0111] Both collars can be formed relatively easily by forming a circumferential cut notch in the contact member 20. The cut notches are formed in the contact member after the two snap-action discs 16, 18 with their through holes 40, 42 have been slipped over the contact member 20.

[0112] As an alternative to such collars, which are produced by introducing cut notches, the two locking elements 50, 52 can also each comprise one or more retaining claws (not shown). Such retaining claws are also preferably integral with the base body 46 of the contact member 20.

[0113] It is advantageous for the function of the switching mechanism 10 if the bimetal snap-action disc 16 is held on the contact member 20 with larger clearance than the snap-action spring disc 18. This guarantees sufficiently free movement of the bimetal snap-action disc 16. At the same time, the slightly smaller clearance between the snap-action spring disc 18 and the contact member 20 enables the best possible electrical contact between these two components.

[0114] Of course, other shapes of the switching mechanism housing 14 are possible. However, it is important that the contact member 20 is able to move downward within the switching mechanism housing 14 when the snap-action discs 16, 18 snap over from the low-temperature position shown in FIG. 1 to the high-temperature position. For this purpose, there must be sufficient space in particular for the contact member 20 so that it does not collide with the bottom wall 30 in the high-temperature position of the switching mechanism 10. As already mentioned, this is enabled by the opening 29 provided in the bottom wall 30.

[0115] In FIGS. 3 and 4, an embodiment of a temperature-dependent switch in which the switching mechanism 10 can be used is shown in each case in a schematic sectional view. The switch is denoted therein in its entirety by reference numeral 100.

[0116] FIG. 3 shows the low-temperature position of the switch 100. FIG. 4 shows the high-temperature position of the switch 100.

[0117] According to the embodiment shown in FIGS. 3 and 4, the switch 100 comprises a switch housing 56 which functions as a housing for the switching mechanism 10. The switching mechanism 10 is inserted into the switch housing 56 together with its switching mechanism housing 14. The switching mechanism 10 corresponds to the embodiment shown in FIG. 1.

[0118] The switch housing 56 comprises a pot-like lower part 58 and a lid part 60 held to the lower part 58 by a folded or flanged edge 62.

[0119] Both the lower part 58 and the lid part 60 are made of an electrically conductive material, preferably metal, in the embodiment shown in FIGS. 3 and 4. An insulating foil 64 is arranged between the lower part 58 and the lid part 60. The insulating foil 64 provides electrical insulation of the lower part 58 with respect to the lid part 60. Likewise, the insulating foil 64 provides a mechanical seal that prevents liquids or contaminants from entering the interior of the housing from outside.

[0120] Since the lower part 58 and the lid part 60 are each made of electrically conductive material, thermal contact can be made via their outer surfaces to an electrical device to be protected. The outer surfaces also serve as the external electrical connection of the switch 100. For example, the outer surface 61 of the lid part 60 can act as the first electrical connection and the outer surface 59 of the lower part 58 can act as the second electrical connection.

[0121] A further insulation layer 66 may be arranged on the outside of the lid part 60, as shown in FIGS. 3 and 4.

[0122] The switching mechanism 10 is arranged clamped between the lower part 58 and the lid part 60. It is particularly important that the contact member 20 is aligned with respect to a counter contact 70, which is arranged on the inside of the lid part 60. This counter contact 70 is also referred to herein as the first stationary contact. The inner side 71 of the lower part 58 serves as the second stationary contact.

[0123] In the low temperature position of the switch 100 shown in FIG. 3, the temperature-independent snap-action spring disc 18 is in its first configuration and the temperature-dependent bimetal snap-action disc 16 is in its low temperature configuration. The snap-action spring disc 18 presses the contact member 20 through the first opening 28 against the counter contact 70, and the switch 100 is thus in its closed position in which an electrically conductive connection is established between the first stationary contact 70 and the second stationary contact 71 via the contact member 20 and the snap-action spring disc 18. Contact pressure between the contact member 20 and the first stationary contact 70 is provided by the snap-action spring disc 18. In contrast, the bimetal snap-action disc 16 is mounted in the switching mechanism housing 14 in this state with virtually no force.

[0124] If the temperature of the device to be protected now increases, and thus the temperature of the switch 100 as well as the bimetal snap-action disc 16 arranged therein increases to the switching temperature of the bimetal snap-action disc 16 or above the switching temperature, the bimetal snap-action disc 16 snaps over from its convex low-temperature position shown in FIG. 3 to its concave high-temperature position shown in FIG. 4. During this snap-over, the outer edge of the bimetal snap-action disc 16 supports against the first housing side 22 of the switching mechanism housing 14. More specifically, the bimetal snap-action disc 16 bears against an inner surface 72 of the bent-over upper portion 34 arranged inside the switching mechanism housing 14. As a result, the snap-action spring disc 18 simultaneously flexes downward at its center, causing the snap-action spring disc 18 to snap over from its first stable geometric configuration shown in FIG. 3 to its second stable geometric configuration shown in FIG. 4.

[0125] In the case where the upper portion 34 is formed by a plurality of individual segments 35 arranged in a circumferentially distributed manner, as shown in FIG. 2, the said inner surface 72 is formed jointly by the bottom sides of the individual segments 35.

[0126] FIG. 4 shows the high-temperature position of the switch 100, in which it is open. The circuit is thus interrupted.

[0127] When the device to be protected and thus the switch 100 together with the bimetal snap-action disc 16 then cool down again, the bimetal snap-action disc 16 snaps back into its low-temperature position upon reaching the reset temperature, which is also referred to as the snap-back temperature, as shown in FIG. 3, for example. Thus, a reversible switching behavior can be realized.

[0128] Of course, it is also possible for the switch 100 to be prevented from switching back to the high-temperature position once it has been snapped over by means of a corresponding locking device. A large number of such locking devices, which are used in particular for one-time switches where a switch-back is to be prevented, are already known from the prior art.

[0129] It should also be mentioned that the switch housing 56 shown in FIGS. 3 and 4 is an exemplary switch housing. It is understood that the switching mechanism 10 can be used in switches of completely different designs, in particular due to the provision of the extra switching mechanism housing 14.

[0130] It is to be understood that the foregoing is a description of one or more preferred exemplary embodiments of the invention. The invention is not limited to the particular embodiment(s) disclosed herein, but rather is defined solely by the claims below. Furthermore, the statements contained in the foregoing description relate to particular embodiments and are not to be construed as limitations on the scope of the invention or on the definition of terms used in the claims, except where a term or phrase is expressly defined above. Various other embodiments and various changes and modifications to the disclosed embodiment(s) will become apparent to those skilled in the art. All such other embodiments, changes, and modifications are intended to come within the scope of the appended claims.

[0131] As used in this specification and claims, the terms for example, e.g., for instance, such as, and like, and the verbs comprising, having, including, and their other verb forms, when used in conjunction with a listing of one or more components or other items, are each to be construed as open-ended, meaning that the listing is not to be considered as excluding other, additional components or items. Other terms are to be construed using their broadest reasonable meaning unless they are used in a context that requires a different interpretation.