TEMPERATURE-DEPENEDENT SWITCHING MECHANISM AND TEMPERATURE-DEPENDENT SWITCH

Abstract

A temperature-dependent switching mechanism for a temperature-dependent switch having a temperature-dependent bimetal disc; a temperature-independent spring disc; an electrically conductive contacting part on which the bimetal disc and the spring disc are captively held; and a retaining ring which has a main body that is made of an electrically conductive material and surrounds a peripheral edge of the spring disc and, as a result, captively holds the spring disc.

Claims

1. A temperature-dependent switching mechanism for a temperature-dependent switch, comprising: a temperature-dependent bimetal disc; a spring disc; an electrically conductive contacting part on which the temperature-dependent bimetal disc and the spring disc are captively held; and a retaining ring comprising a main body that is made of an electrically conductive material and that surrounds a peripheral edge of the spring disc to captively hold the spring disc.

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

3. The temperature-dependent switching mechanism according to claim 1, wherein the retaining ring at least partially surrounds the peripheral edge of the spring disc from a circumferential side of the spring disc, an upper side of the spring disc running transversely to the circumferential side, and a lower side of the spring disc opposite the upper side.

4. The temperature-dependent switching mechanism according to claim 1, wherein the peripheral edge of the spring disc is clamped in the retaining ring.

5. The temperature-dependent switching mechanism according to claim 1, wherein a clamping element is arranged in the main body, and the peripheral edge of the spring disc is arranged between the clamping element and the main body.

6. The temperature-dependent switching mechanism according to claim 5, wherein the main body of the retaining ring extends about a central axis and defines a receptacle pocket which is open towards the central axis and in which the clamping element and the peripheral edge of the spring disc are arranged.

7. The temperature-dependent switching mechanism according to claim 1, wherein the main body is a single integral piece.

8. The temperature-dependent switching mechanism according to claim 1, wherein the temperature-dependent bimetal disc and the spring disc are arranged on top of one another in a height direction, and wherein a height of the electrically conductive contacting part measured in the height direction is larger than a height of the retaining ring measured in the height direction.

9. The temperature-dependent switching mechanism according to claim 1, wherein the electrically conductive contacting part is arranged so as to be centric relative to the retaining ring, and wherein the electrically conductive contacting part protrudes from the retaining ring at least on a first side.

10. The temperature-dependent switching mechanism according to claim 1, wherein an internal diameter of the main body of the retaining ring is smaller than an external diameter of the spring disc but larger than an external diameter of the temperature-dependent bimetal disc, the internal diameter of the main body of the retaining ring, the external diameter of the spring disc, and the external diameter of the temperature-dependent bimetal disc being measured parallel to one another.

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

12. The temperature-dependent switching mechanism according to claim 11, wherein an internal diameter of the main body of the retaining ring is smaller than an external diameter of the spring disc but larger than an external diameter of the temperature-dependent bimetal disc, the internal diameter of the main body of the retaining ring, the external diameter of the spring disc, and the external diameter of the temperature-dependent bimetal disc being measured parallel to one another and orthogonal to the central axis.

13. A temperature-dependent switch comprising a temperature-dependent switching mechanism, a first external terminal, and a second external terminal, wherein the temperature-dependent switching mechanism is configured to switch depending on its temperature between a closed position, in which the temperature-dependent switching mechanism establishes an electrically conductive connection between the first external terminal and the second external terminal, and an open position, in which the temperature-dependent switching mechanism disconnects the electrically conductive connection, and wherein the temperature-dependent switching mechanism comprises: a temperature-dependent bimetal disc; a spring disc; an electrically conductive contacting part on which the temperature-dependent bimetal disc and the spring disc are captively held; and a retaining ring comprising a main body that is made of an electrically conductive material and that surrounds a peripheral edge of the spring disc to captively hold the spring disc.

14. The temperature-dependent switch according to claim 13, further comprising a switch housing that comprises a lower part and a cover part, wherein the cover part is fastened to the lower part and closes the lower part, and wherein each of the lower part and the cover part are made of an electrically isolating material.

15. The temperature-dependent switch according to claim 13, wherein the retaining ring forms a first electrode, and wherein the lower part supports the first electrode and a second electrode and holds the first electrode and the second electrode spaced apart from one another along a height direction, wherein the first electrode is electrically connected to the first external terminal by way of a line connection element that is aligned transversely to the first electrode and the second electrode and that is arranged in the lower part, wherein the second electrode is electrically connected to the second external terminal, and wherein the first external terminal and the second external terminal are led through the lower part in a common connection plane orthogonal to the height direction.

16. The temperature-dependent switch according to claim 15, wherein the retaining ring bears on the line connection element.

17. The temperature-dependent switch according to claim 13, wherein the temperature-dependent bimetal disc is configured to change its shape depending on its temperature so as to switch the temperature-dependent switching mechanism between the closed position and the open position, and wherein the spring disc in the closed position of the temperature-dependent switching mechanism is configured to establish the electrically conductive connection in which said spring disc is supported on the retaining ring and generates a mechanical contact pressure by way of which the electrically conductive contacting part is pressed against a stationary mating contact.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0064] FIG. 1 shows a schematic sectional view of an exemplary embodiment of a temperature-dependent switch comprising a temperature-dependent switching mechanism, wherein the temperature-dependent switching mechanism of the switch is in its closed position;

[0065] FIG. 2 shows a schematic sectional view of the exemplary embodiment of the switch shown in FIG. 1, wherein the temperature-dependent switching mechanism of the switch is in its open position;

[0066] FIG. 3 shows a schematic view from above of the switch illustrated in FIGS. 1 and 2, wherein components in the interior of the switch are illustrated by dashed lines; and

[0067] FIG. 4 shows a schematic view from above of the switching mechanism according to an exemplary embodiment.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0068] FIGS. 1 and 2 show in each case a schematic sectional view of an exemplary embodiment of a temperature-dependent switch, in which a switching mechanism is used. The switch therein in its entirety is denoted by the reference sign 10.

[0069] FIG. 1 shows the closed position of the switch 10. FIG. 2 shows the open position of the switch 10.

[0070] The switch 10 has a temperature-dependent switching mechanism 12. The switching mechanism 12, as a function of its temperature, is configured to switch the switch 10 from its closed position to its open position, and vice versa.

[0071] In the closed position of the switch 10, shown in FIG. 1, the switching mechanism 12 establishes an electrically conductive connection between the two external terminals 14, 16 of the switch 10. In contrast, in the open position of the switch 10, shown in FIG. 2, the switching mechanism 12 disconnects the electrically conductive connection between the first external terminal 14 and the second external terminal 16.

[0072] The temperature-dependent switching mechanism 12 has a temperature-dependent bimetal disc 18, a temperature-independent spring disc 20, a movable contacting part 22 as well as a retaining ring 24. The mentioned components 18-24 of the switching mechanism 12 are captively connected to one another.

[0073] The spring disc 20 has a central bore through which the contacting part 22 is guided. The inner edge 26 of the spring disc 20 is fixedly clamped on the contacting part 22. More specifically, the contacting part 22 is of a two-part construction and has a first component 28, which forms the primary body of the contacting part 22, and a second component 30, which is designed as a type of encircling shoulder and is fixedly connected to the first component 28 of the contacting part 22. The spring disc 20 by way of its inner edge 26 is clamped between the first component 28 and the second component 30 of the contacting part 22.

[0074] The peripheral edge 32 of the spring disc 20 is captively held on the retaining ring 24. The retaining ring 24 has a main body 34 and a clamping element 36 which is arranged in the main body 34. The main body 34 of the retaining ring 24 is formed from metal or any other electrically conducting material. This main body 34 is a rotationally symmetrical body which extends about a central axis 38 and forms a type of receptacle pocket 40 in which the clamping element 36 and the encircling outer edge 32 of the spring disc 20 are arranged.

[0075] As is shown in FIGS. 1 and 2, the receptacle pocket 40 formed by the main body 34 of the retaining ring 24 is open towards the central axis 38 and substantially U-shaped or J-shaped in the cross section. The receptacle pocket 40 formed by the main body 34 of the retaining ring 24 extends at least in portions along the retaining ring 24. The receptacle pocket 40 can, but does not mandatorily have to, extend along the entire circumference of the retaining ring 24, as will be explained in more detail hereunder.

[0076] The clamping element 36 is preferably a spacer ring which is designed as a rotational solid and is adapted to the shape of the retaining ring, or the shape of the receptacle pocket 40 formed by the main body 34, respectively. This spacer ring preferably sits in the receptacle pocket 40 with a precise fit. The spacer ring, or the clamping element 36, respectively, is preferably made of an electrically isolating material, e.g. from plastics material.

[0077] While the spring disc 20 by way of its peripheral edge 32 is clamped between the main body 34 and the clamping element 36 of the retaining ring 24, and by way of its inner edge 26 is fastened to the contacting part 22 in a clamping manner, the bimetal disc 18 in the closed position of the switching mechanism 12, shown in FIG. 1, is mounted so as to be largely free of forces acting thereon. The bimetal disc 18 by way of its inner edge 42 is arranged between the second component 30 of the contacting part 22 and the spring disc 20, the second component 30 being designed as an encircling shoulder. As a result of this type of arrangement, the bimetal disc 18 is captively held on the contacting part 22, but with play. In the closed position of the switching mechanism 12, the peripheral edge 44 protrudes into the interior of the switch and is in contact neither with the retaining ring 24 nor with the switch housing 46 in which the switching mechanism 12 is arranged. The peripheral edge 44 of the bimetal disc 18 is thus freely accessible at least from the upper side and from this side not obscured by the retaining ring 24.

[0078] In contrast, the retaining ring 24 surrounds the peripheral edge 32 of the spring disc 20 from the circumferential side 48 as well as from the upper side 50 and lower side 52 of the spring disc 20.

[0079] The bimetal disc 18 and the spring disc 20 are arranged on top of one another in the height direction h. A height H1 of the contacting part 22, measured in the height direction h, is greater than a height H2 of the retaining ring 24 measured in the height direction h. Accordingly, in the closed position of the switching mechanism 12 shown in FIG. 1, the contacting part 22 protrudes downwards from the retaining ring 24. In the closed position shown in FIG. 2, the contacting part 22 protrudes from the retaining ring 24 on both sides (downwards and upwards).

[0080] As is derived from the view from above of the switching mechanism 12 illustrated in FIG. 4, an internal diameter dl of the main body 34 of the retaining ring 24 is smaller than an external diameter D1 of the spring disc 20, but greater than an external diameter D1 of the bimetal disc 18. It is ensured as a result that the spring disc 20 in turn is captively held on the retaining ring 24 and cannot be inadvertently released from the latter. On the other hand, it is ensured as a result that the bimetal disc 18 does not collide with the retaining ring 24 when the former moves in a temperature-dependent manner.

[0081] The main body 34 of the retaining ring 24 is configured in one piece. The main body 34 has a top wall 54, a base wall 56 which is integrally connected to the top wall 54 and runs parallel to the latter, and a side wall 58 which runs transversely to the top wall 54 and the base wall 56. The side wall 58 connects the top wall 54 to the base wall 56 and is integrally connected to both.

[0082] While the side wall 58 runs along the entire circumference of the main body 34 of the retaining ring 24, the top wall 54 and the base wall 56 of the main body 34 of the retaining ring 24 do not mandatorily have to run in an encircling manner. It is indeed fundamentally possible that the top wall 54 runs along the entire circumference of the main body 34 of the retaining ring 24. However, for the avoidance of folds being formed, it is advantageous for the top wall 54 of the main body 34 of the retaining ring 24 to have a plurality of separate segments 60 which are folded back and arranged so as to be distributed in the circumferential direction, as is shown in the view from above in FIG. 4.

[0083] In the production of the switch 10, the switching mechanism 12 is inserted into the switch housing 46 as an entirety. This switch housing 46 has a lower part 62 which is designed in the manner of a pot and is closed by a cover part 64 that is designed separately from the switch housing 46. The lower part 62 as well as the cover part 64 in the switch are produced from an electrically isolating material, e.g. from plastics material. The upper edge 66 of the lower part 62 is sealed to the cover part in a vacuum-tight manner by compression. For example, in the production of the switch 10 the upper edge 66 of the lower part 62 is radially formed inwards by hot forming in such a way that the lower part 62 is fixedly connected to the cover part 64, and the interior of the switch is sealed in particular so as to protect the switching mechanism 12 against the ingress of moisture or other contaminations invading the interior of the switch.

[0084] By virtue of the lower part 62 and the cover part 64 being formed from an electrically isolating material, the switch housing 46 per se does not serve as an electrical connection of the switching mechanism 12. Instead, the main body 34 of the retaining ring 24, which is formed from an electrically conductive material, serves as the first electrode 68. A second electrode 70 is embedded in the lower part 62 of the switch housing 46. This second electrode 70 is integrally connected to the second external terminal 16. The second electrode 70 can be, e.g. a sheet-metal plate which is integrated directly into the lower part 62 of the switch housing 46. For example, in the production of the switch 10, the lower part 62 is produced as a plastic injection-molded part by overmolding the second electrode 70.

[0085] The two electrodes 68, 70 of the switching mechanism 12 are mutually spaced apart in the height direction h by the lower part 62 of the switch housing 46. The retaining ring 23 herein bears on top of a shoulder 72 formed in the interior of the lower part, and is simultaneously in planar contact with a line connection element 74 which is electrically connected to the first external terminal 14. This line connection element 74 can be, for example, a sheet-metal conductor or any other electrical conductor which is integrated into the lower part 62 of the switch housing 46.

[0086] The line connection element 74 electrically connects the main body 34 of the retaining ring 24, which functions as the first electrode 68 of the switching mechanism 12, to the first external terminal 14. In this way, it is nevertheless possible to route the two external terminals 14, 16 from the inside to the outside through the lower part 62 of the switch housing 46 at the same height, despite the two electrodes 68, 70 being arranged so as to be offset in the height direction h. Accordingly, in the sectional views shown in FIGS. 1 and 2, the first external terminal 14 is arranged behind the second external terminal 16, because the first external terminal 14 is arranged at the same height as the second external terminal 16 and runs parallel to the second external terminal 16. The latter can be seen in particular when viewed conjointly with the view from above of the switch 10 shown in FIG. 3.

[0087] As is shown in FIG. 3, the two external terminals 14, 16 run parallel to one another outside the switch housing 46 and, by virtue of the line connection element 74, can be arranged in a common connection plane E which is indicated by a dashed line in FIGS. 1 and 2.

[0088] The line connection element 74 furthermore offers the advantage that the switching mechanism 12 in the production of the switch 10 has only to be inserted into the lower part 62, the electrical contact between the main body 34 of the retaining ring 24 and the first external terminal 14 then being automatically established.

[0089] It is to be pointed out here that FIG. 3 shows a view from above of the switch 10, wherein some components (e.g. components 18, 20 and 34) which are arranged in the interior of the switch housing 46 are indicated by dashed lines because said components are actually not visible from the outside. The dashed lines indicate in each case the contour, or the external circumference, respectively, of the respective component. The second electrode 70, which is likewise indicated by dashed lines in FIG. 3, runs obliquely, or at an angle, to the second external terminal 16 but, conjointly with the second external terminal 16, lies in the connection plane E, as has already been mentioned. Therefore, FIGS. 1 and 2 show the section along the section line A-A.

[0090] It is furthermore understood that the line connection element 74 in the case of a section line A-A of this type, and in the case of its arrangement shown in FIG. 3, would not actually be visible in FIGS. 1 and 2 but would be obscured by parts of the housing lower part 62. However, the views shown in FIGS. 1 and 2 are not true-to-scale and true-to-detail sectional views but schematic sectional views in which the line connection element 74 is schematically illustrated for the purpose of better explaining the arrangement of the latter.

[0091] It is moreover understood that the second electrode 70 does not mandatorily have to run at an angle, or obliquely, to the second external terminal 16, as is shown in FIG. 3. In principle, the second electrode 70 can also be co-aligned with the second external terminal 16. In such a case, it is preferable for the second external terminal 16, conjointly with the second electrode 70, to run in the radial direction of the switch housing 46. If the second external terminal 16 is arranged to be centric, thus compared with the position shown in FIG. 3, offset in parallel upwards in the direction of the first external terminal 14, a parallel alignment of the two external terminals 14, 16 is also possible in this instance. With reference to FIG. 3, the second external terminal 16 and the second electrode 70 in this instance will be arranged in the center of the switch housing 46, in a line parallel to the first external terminal 14.

[0092] The temperature-dependent switching function of the switch 10, which is caused by the temperature-dependent switching mechanism 12, will be explained hereunder by means of FIGS. 1 and 2.

[0093] As has already been mentioned, FIG. 1 shows the closed position of the switch 10, in which the temperature-dependent switching mechanism 12 establishes an electrical contact between the two external terminal 14, 16 in the interior of the switch. In this closed position the spring disc 20 presses the contacting part 22 against a stationary mating contact 76 which is fastened to the second electrode 70. In the closed position of the switch 10, the bimetal disc 18 is non-energized and mounted so as to be free of forces acting thereon. The contact pressure, like the current flow, are caused only by the spring disc 20. To this end, the spring disc 20 by way of its peripheral edge 32 is supported on the clamping element 36, and presses the contact part 22, which is centrally arranged, against the mating contact 76. The current flow takes place from the first external terminal 14 by way of the line connection element 74, the retaining ring 24, the spring disc 20, the movable contacting part 22, the stationary mating contact 76 and the second electrode 70 to the second external terminal 16 (or in the reverse direction).

[0094] In the closed position, or low-temperature position, respectively, of the switch 10, shown in FIG. 1, the spring disc 20 is thus in its first configuration, and the bimetal disc 18 is in its low-temperature configuration. If, proceeding from this situation, the temperature of the apparatus to be protected, and thus the temperature of the switch 10 and the temperature of the bimetal disc 18, increase to the response temperature of the bimetal disc 18 or beyond this response temperature, the bimetal disc 18 springs from its convex low-temperature position shown in FIG. 1 to its concave high-temperature position, the latter being shown in FIG. 2. In this springing action, the bimetal disc 18, by way of its outer edge 44, is supported on the spring disc 20. As a result, the spring disc 20 simultaneously bends upwards at its center, so that the spring disc 20 springs from its first stable geometric configuration shown in FIG. 1 to its second geometrically stable configuration shown in FIG. 2. As a result, the contacting part 22 is lifted from the mating contact 76, and the electrically conductive connection between the two external contacts 14, 16 is interrupted.

[0095] Accordingly, the apparatus to be protected is de-energized so that it can cool down again. If the temperature subsequently drops back to a temperature below the so-called springback temperature of the bimetal disc 18, the latter springs back from its high-temperature position, shown in FIG. 2, to its low-temperature position, shown in FIG. 1, as a result of which the electrically conductive connection between the two external terminals 14, 16 is closed again. Depending on the specific application, such a reset can be prevented by an anti-reset lock, or a heating resistor which is electrically wired parallel to the switching mechanism 12 and causes a so-called self-maintaining function.

[0096] It is understood that various other potential modifications of the exemplary embodiment shown in the drawings are possible in the switch 10, without departing from the spirit and scope of the present disclosure. For example, the switch housing 46 does not at all have to be of a circular design in the longitudinal section, but may also be of an oval or angular design. Accordingly, the two discs 18, 20 likewise do not have to be designed as circular discs. The shape of the retaining ring 24 as well as the shape of the contacting part 22 can likewise be of a somewhat different design and does not mandatorily have to have the exact shape as is illustrated in the drawings presently shown.

[0097] 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.

[0098] 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.