TEMPERATURE-DEPENDENT SWITCH

Abstract

A temperature-dependent switch, comprising a temperature-dependent switching mechanism having a switching mechanism unit, and having a switching mechanism housing, in which the switching mechanism unit is arranged and held captively therein, wherein the switching mechanism housing comprises a first base body composed of electrically conductive material. The temperature-dependent switch furthermore comprises a switch housing having a second base body composed of electrically insulating material, in which the switching mechanism housing is arranged and held captively therein, wherein the switch housing comprises a stationary contact part. The first 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 circumferential side extending between and transversely to the first and the second housing sides, and on the first housing side comprises an opening through which a movable contact part of the switching mechanism unit interacts with the stationary contact part. The second base body of the switch housing surrounds the first housing side and the circumferential housing side of the switching mechanism housing.

Claims

1. A temperature-dependent switch, comprising: a temperature-dependent switching mechanism having a switching mechanism unit, which comprises a movable contact part coupled to a bimetallic snap-action disc, and having a switching mechanism housing, in which the switching mechanism unit is arranged and held captively therein, wherein the switching mechanism housing comprises an electrically conductive first base body; a switch housing having an electrically insulating second base body, in which the switching mechanism housing is arranged and held captively therein, wherein the switch housing comprises a stationary contact part, which acts as a mating contact to the movable contact part; a first connection contact part, which is electrically connected to the first base body; and a second connection contact part, which is electrically connected to the stationary contact part: wherein the first base body surrounds the switching mechanism unit from a first housing side, a second housing side opposite the first housing side, and a housing circumferential side extending between and transversely to the first and the second housing sides, wherein the first base body comprises on the first housing side an opening through which the movable contact part interacts with the stationary contact part, and wherein the second base body surrounds the first housing side and the circumferential housing side of the switching mechanism housing.

2. The temperature-dependent switch according to claim 1, wherein a part of the first base body that forms the second housing side of the switching mechanism housing forms a freely accessible outside of the switch.

3. The temperature-dependent switch according to claim 1, wherein the first connection contact part is electrically connected in an interior of the switch housing to the first base body and is guided outwards out of the switch housing through the second base body.

4. The temperature-dependent switch according to claim 1, wherein the second connection contact part is electrically connected in an interior of the switch housing to the stationary contact part and is guided outwards out of the switch housing through the second base body.

5. The temperature-dependent switch according to claim 1, wherein the switch housing, on an inner side facing the switching mechanism housing, comprises a first connection contact-part receptacle, in which the first connection contact part is arranged, and a second connection contact-part receptacle, in which the second connection contact part is arranged.

6. The temperature-dependent switch according to claim 6, wherein the first connection contact-part receptacle comprises a first recess, in which the first connection contact part is embedded, and wherein the second connection contact-part receptacle comprises a second recess, in which the second connection contact part is embedded.

7. The temperature-dependent switch according to claim 6, wherein the first recess and the second recess lie in a common plane.

8. The temperature-dependent switch according to claim 1, wherein the first connection contact part at least partially surrounds the second connection contact part.

9. The temperature-dependent switch according to claim 1, wherein an electrically insulating intermediate layer part is arranged between the second connection contact part and the switching mechanism housing.

10. The temperature-dependent switch according to claim 9, wherein the switching mechanism housing rests with a first housing portion, which is arranged on the first housing side, on the intermediate layer part and with a second housing portion, which is arranged on the first housing side, on the first connection contact part.

11. The temperature-dependent switch according to claim 9, wherein the switching mechanism housing rests with a first housing portion, which is arranged on the first housing side, on the intermediate layer part and with a second housing portion, which is arranged on the first housing side, on an electrically conductive connecting part that is interposed between the second housing portion and the first connection contact part.

12. The temperature-dependent switch according to claim 11, wherein the connecting part is L-shaped in cross section and abuts the first housing side and the housing circumferential side of the switching mechanism housing.

13. The temperature-dependent switch according to claim 11, wherein the first connection contact part is electrically connected to the first base body via the connecting part.

14. The temperature-dependent switch according to claim 1, wherein an outer circumferential surface of the switching mechanism housing that is arranged on the housing circumferential side abuts an inner circumferential surface of the switch housing that is arranged in an interior of the switch housing.

15. The temperature-dependent switch according to claim 1, wherein the switching mechanism is configured so as, below a response temperature of the bimetallic snap-action disc, to keep the switch in a low-temperature position in which the switching mechanism establishes via the movable contact part an electrical connection between the first connection contact part and the second connection contact part, and; upon exceeding the response temperature, to move the switch into a high-temperature position in which the switching mechanism interrupts the electrical connection.

16. The temperature-dependent switch according to claim 15, wherein the bimetallic snap-action disc is configured to snap over from a geometrically stable low-temperature configuration into a geometrically stable high-temperature configuration upon exceeding the response temperature, and wherein the bimetallic snap-action disc is supported in its high-temperature configuration on a supporting surface, which is arranged on the first housing side of the switching mechanism housing and is formed on the first base body, and thereby keeps the movable contact part at a distance from the stationary contact part.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0068] FIG. 1 shows a schematic sectional view of the temperature-dependent switch according to an exemplary embodiment, the switch being shown in its low-temperature position;

[0069] FIG. 2 shows a schematic sectional view of the switch shown in FIG. 1, the switch being shown in its high-temperature position;

[0070] FIG. 3 shows a schematic sectional view illustrating a processing step during the manufacturing of the temperature-dependent switch according to the exemplary embodiment shown in FIG. 1; and

[0071] FIG. 4 shows a schematic top view from above of the switch housing of the temperature-dependent switch according to the exemplary embodiment shown in FIG. 1.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0072] FIGS. 1-2 show an exemplary embodiment of the switch in each case in a schematic sectional view. The switch is identified therein in its entirety by the reference number 100.

[0073] FIG. 1 shows the low-temperature position of the switch 100. FIG. 2 shows the high-temperature position of the switch 100.

[0074] The switch 100 comprises a temperature-dependent switching mechanism 10, which is arranged in a switch housing 12. The switch housing 12 comprises a base body 14 (in the present case referred to as second base body) composed of insulating material, e.g. composed of plastic. This base body 14 forms the lower part of the switch 100.

[0075] The switching mechanism 10 comprises a functional switching mechanism unit 16 and a switching mechanism housing 18 surrounding said switching mechanism unit 16. The switching mechanism housing 18 at least partially surrounds the switching mechanism unit 16 from all six spatial directions. However, as explained in detail below, the switching mechanism housing 18 is configured as a partially open housing, and therefore the switching mechanism unit 16 is accessible from outside the switching mechanism housing 18 from at least one spatial direction, preferably from only one spatial direction.

[0076] Owing to the fact that the switching mechanism housing 18 at least partially surrounds the switching mechanism unit 16 from all six spatial directions, the switching mechanism unit 16 is held captively in the switching mechanism housing 18. The switching mechanism unit 16 therefore cannot be detached from the switching mechanism housing 18.

[0077] As long as the switching mechanism 10 is not installed in the switch 100 or its switch housing 12, there is preferably a certain clearance between the switching mechanism unit 16 and the switching mechanism housing 18. However, the switching mechanism unit 16 is firmly braced in the installation state of the switch 100 that is shown in FIG. 1, In the low-temperature position of the switch 100 that is shown in FIG. 1, the switching mechanism unit 16 is damped between the switch housing 12 and the switching mechanism housing 18.

[0078] The switching mechanism unit 16 is constructed in three parts according to the present exemplary embodiment. The switching mechanism unit 16 comprises a temperature-dependent bimetallic snap-action disc 20, a temperature-independent spring snap-action disc 22 and a movable contact part 24. The bimetallic snap-action disc 20 and the spring snap-action disc 22 are held captively on the contact part 24. The switching mechanism unit 16 can thus be produced in advance as a semi-finished product and then inserted as a whole into the switching mechanism housing 18.

[0079] The switching mechanism 10 together with the switching mechanism unit 16 and the switching mechanism housing 18 also form a semi-finished product for the temperature-dependent switch 100 produced from it later on. Since the three components 20, 22, 24 of the switching mechanism unit 16 are connected captively to one other and the switching mechanism unit 16 is held captively in the switching mechanism housing 18, the switching mechanism 10 can be kept in stock as bulk material until it is installed in the temperature-dependent switch 100.

[0080] The switching mechanism housing 18 comprises a base body 26 (in the present case referred to as first base body) composed of electrically conductive material. Said first base body 26 of the switching mechanism housing 18 surrounds the switching mechanism unit 16 from a first housing side 28, from a second housing side 30 opposite the first housing side 28, and also from a housing circumferential side 32 extending between and transversely to the first and the second housing sides 28, 30 (see FIG. 3).

[0081] Preferably, the switching mechanism housing 18 completely surrounds the switching mechanism unit 16 both from the second housing side 30 and from the housing circumferential side 32. The second housing side 30 and the housing circumferential side 32 thus preferably form dosed housing sides of the switching mechanism housing 18. Only the first housing side 28 is a partially open housing side of the switching mechanism housing 18.

[0082] In other words, the housing circumferential side 32 surrounds the switching mechanism unit 16 along the entire circumference, i.e. on a total of four spatial directions oriented orthogonally with respect to one other. Furthermore, the switching mechanism housing 18 completely surrounds the switching mechanism unit 16 from a further spatial direction, namely from a spatial direction oriented orthogonally to the second housing side 30. Only from the sixth spatial direction, which is oriented orthogonally to the first housing side 28, does the switching mechanism housing 18 only partially surround the switching mechanism unit 16.

[0083] On the first housing side 28, the switching mechanism housing 18 comprises an opening 34 (see FIG. 3) through which the movable contact part 24 is accessible from outside the switching mechanism housing 18. Through said opening 34 in the switching mechanism housing 18, the movable contact part 24 of the switching mechanism 10 interacts with a stationary contact part 36, which is arranged on an inner side 38 of the switch housing 12 (see FIG. 1). A diameter of the opening 34 in the first base body 26 of the switching mechanism housing 18 is smaller than a diameter, measured parallel thereto, of the bimetallic snap-action disc 20 and/or of the spring snap-action disc 22. Thus, although the movable contact part 24 is accessible from outside the switching mechanism housing 18 through the opening 34, the bimetallic snap-action disc 20 and the spring snap-action disc 22 cannot, however, become detached from the switching mechanism housing 18 or emerge therefrom.

[0084] The first base body 26 of the switching mechanism housing 18 is composed of electrically conductive material, e.g. composed of metal. The second housing side 30 of said electrically conductive base body 26 forms a freely accessible outside of the switch 100 (see FIG. 1) in the exemplary embodiment shown here. The first housing side 28 and the housing circumferential side 32 of the switching mechanism housing 18 are arranged completely within the switch housing 12 and are therefore not accessible from outside the switch 100.

[0085] The opening 34 arranged on the first housing side 28 in the switching mechanism housing 18 is completely concealed by the second base body 14 of the switch housing 12 when the switch 100 is installed. The switching mechanism housing 18 is arranged in the switch housing 12 and held captively thereon. For this purpose, during the manufacturing of the switch 100, an upper circumferential edge 40 is pressed radially inwards onto the switching mechanism housing 18. This process, which is schematically indicated by means of the arrows 42 in FIG. 3, is preferably carried out by means of a hot stamping process. The interfaces between the upper edge 40 of the base body 14 of the switch housing 12 and the base body 26 of the switching mechanism housing 18 can be additionally sealed by means of further sealing agents, e.g. with the aid of a sealing varnish. Thus, the switching mechanism unit 16 is hermetically sealed to the outside in the interior of the switch 100. Therefore, liquids or other contaminants do not enter the interior of the switch.

[0086] Before the switch housing 12 is connected to the switching mechanism housing 18 and sealed, the switching mechanism housing as a whole with the switching mechanism unit 16 located therein, as shown in FIG. 3, is inserted into the switch housing 12. The corresponding contacts for the electrical connection of the switching mechanism are already pre-assembled in the switch housing 12, and therefore the switching mechanism 10 does not have to be connected separately, and instead the electrical connection thereof is automatically already undertaken when the switching mechanism housing 18 is inserted into the switch housing 12.

[0087] There are two connection contact parts 44, 46 on the switch housing 12. The two connection contact parts 44, 46 each comprise a cable lug 48, 50 and a connecting conductor 52, 54 connected to the cable lug 48, 50. The connecting conductor 52 of the first connection contact part 44 is electrically connected to the electrically conductive first base body 26 of the switching mechanism housing 18 in the interior of the switch 100. The connecting conductor 54 of the second connection contact part 46 is electrically connected to the stationary contact part 36 in the interior of the switch 100. FIG. 4 shows the switch housing 12 provided with the two connection contact parts 44, 46 in a top view from above before the switching mechanism 10 is inserted into the switch housing 12.

[0088] The two connecting conductors 52, 54 of the connection contact parts 44, 46 are each guided from the outside through the housing wall 56 of the second base body 14 into the interior of the switch. The connecting conductor 52 of the first connection contact part 44 is arranged in a first connection contact-part receptacle 58, which is configured as a first recess/depression 60 on the inside 38 of the switch housing 12. The depression 60, which forms the first connection contact-part receptacle 58, is preferably configured in such a way that the connecting conductor 52 of the first connection contact part 44 is accommodated in a precisely fitting manner therein.

[0089] The connecting conductor 54 of the second connection contact part 46 is arranged in a second connection contact-part receptacle 62. Said second connection contact-part receptacle 62 is configured as a second depression 64, which is introduced into the inside 38 of the electrically insulating base body 14 of the switch housing 12.

[0090] The recesses/depressions 60, 64, which form the two connection contact-part receptacles 58, 62, preferably lie in a common plane. The first recess 58 at least partially surrounds the second depression 64 (see FIG. 4).

[0091] The first depression 60 and the first connecting conductor 52 have the shape of a circular ring sector, as viewed in the top view (see FIG. 4). The second depression 64 and the second connecting conductor 54 arranged therein, on the other hand, can be rectilinear or, as shown in FIG. 4, angled.

[0092] The connecting conductor 52 of the first connection contact part 44 is connected to the switching mechanism housing 18 via a connecting part 66 in the installed state of the switch 100. This connecting part 66 is a component composed of electrically conductive material, which establishes the electrical contact between the first connection contact part 44 and the electrically conductive base body 26 of the switch housing 18. In the exemplary embodiment shown here, said connecting part 66 is L-shaped, as viewed in cross section, in order to be able to provide as large an electrical contact surface as possible. The connecting part 66 rests directly on the upper side of the first connecting conductor 52.

[0093] In principle, this connecting part 66 is not absolutely necessary, since the first connecting conductor 52 of the first connection contact part 44 can also be connected directly to the base body 26 of the switching mechanism housing 18. However, the connecting part 66 also has the advantage that a relatively simple height compensation is possible therewith.

[0094] The last-mentioned height compensation is particularly necessary because an intermediate layer part 68 is arranged between the connecting conductor 54 of the second connection contact part 46 and the base body 26 of the switching mechanism housing 18. Said intermediate layer part 68 is composed of electrically insulating material. It provides electrical insulation of the switching mechanism housing 18 in relation to the second connection contact part 46.

[0095] The upper side of the connecting part 66 preferably lies in a plane with the upper side of the intermediate layer part 68, and therefore the switching mechanism housing 18 rests flat with its first housing side 28 on the two parts 66, 68.

[0096] In the installed state of the switch 100, an outer circumferential surface 70 arranged on the housing circumferential side 32 of the switching mechanism housing 18 abuts an inner circumferential surface 72 arranged in the interior of the switch housing 12 (see FIGS. 1 and 3). Preferably, the outer circumferential surface 70 lies in a precisely fitting manner on the inner circumferential surface 72. The switching mechanism 10 is thus already automatically aligned correctly with respect to the stationary contact part 36 on being inserted into the switch housing 12. More specifically, during the installation of the switch 100, the movable contact part 24 of the switching mechanism 10 is aligned with respect to the stationary contact part 36.

[0097] In the low-temperature position of the switch 100 that is shown in FIG. 1, the electrical current flows, i.e. from the first connection contact part 44 via the electrically conductive base body 26 of the switching mechanism housing 18, the spring snap-action disc 22, the movable contact part 24 and the stationary contact part 36 to the second connection contact part 46.

[0098] In the low-temperature position of the switch 100, the temperature-independent spring snap-action disc 22 is in its first configuration and the temperature-dependent bimetallic snap-action disc 20 is in its low-temperature configuration. The spring snap-action disc 22 presses the movable contact part 24 against the stationary contact part 36, which acts as a mating contact. The switch 100 is thus in its closed position, in which an electrically conductive connection between the two connection contact parts 44, 46 is produced.

[0099] The contact pressure between the movable contact part 24 and the stationary contact part 36 is produced by the spring snap-action disc 22. In this state, by contrast, the bimetallic snap-action disc 20 is mounted virtually without any force in the switching mechanism housing 18.

[0100] If the temperature of the device to be protected and thus the temperature of the switch 100 and of the bimetallic snap-action disc 20 arranged therein increases to the switching temperature of the bimetallic snap-action disc 20 or above the switching temperature, the bimetallic snap-action disc 20 snaps over from its concave low-temperature position shown in FIG. 1 into its convex high-temperature position shown in FIG. 2. During said snapping-over, the bimetallic snap-action disc 20 is supported with its outer edge 74 on a supporting surface 76 arranged on the first housing side 28 of the switching mechanism housing 18 (see FIG. 2). This means that the spring snap-action disc 22 is simultaneously deflected upwards at its center such that the spring snap-action disc 22 snaps over from its first stable geometric configuration shown in FIG. 1 into its second geometrically stable configuration shown in FIG. 2.

[0101] FIG. 2 shows the high-temperature position of the switch 100, in which the latter is open. The current circuit is therefore interrupted.

[0102] When the device to be protected and thus the switch 100 together with the bimetallic snap-action disc 20 then cool again, the bimetallic snap-action disc 20 snaps over again into its low-temperature position when the switching-back temperature, which is also referred to as the return temperature, is reached, as is shown for example in FIG. 1. This allows a reversible switching behaviour to be realized.

[0103] In principle, it is also possible to provide the switching mechanism unit 16 without a spring snap-action disc 22. In such a case, the switching mechanism unit 16 then only comprises the bimetallic snap-action disc 20 and the movable contact part 24. The bimetallic snap-action disc 20 not only ensures the switching behaviour, but also simultaneously generates the contact pressure between the movable contact part 24 and the stationary contact part 36 in the low-temperature position of the switch 100. The bimetallic snap-action disc 20 is then used as a live component of the switching mechanism 10.