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EP-4528772-B1 - TEMPERATURE-DEPENDENT SWITCHING DEVICE AND TEMPERATURE-DEPENDENT SWITCH

EP4528772B1EP 4528772 B1EP4528772 B1EP 4528772B1EP-4528772-B1

Inventors

  • HOFSAESS, MARCEL P.

Dates

Publication Date
20260513
Application Date
20240119

Claims (14)

  1. A temperature-dependent switching mechanism (12) for a temperature-dependent switch (10), wherein the switching mechanism (12) includes: - a temperature-dependent bimetal disc (18); - a temperature-independent spring disc (20); - an electrically conductive contacting part (22) on which the bimetal disc (18) and the spring disc (20) are captively held; and - a retaining ring (24) which comprises a main body (34) that is made of an electrically conductive material and surrounds a peripheral edge (32) of the spring disc (20) and, as a result, captively holds the spring disc (20), characterized in that a clamping element (36) made of electrically insulating material is arranged in the main body (34), and the peripheral edge (32) of the spring disc (20) is arranged between the clamping element (36) and the main body (34).
  2. The temperature-dependent switching mechanism according to claim 1, wherein the retaining ring (24) does not contact the bimetal disc (18), and permits a peripheral edge (44) of the bimetal disc (18) to be freely accessible at least from an upper side of the bimetal disc (18).
  3. The temperature-dependent switching mechanism according to claim 1 or 2, wherein the retaining ring (24) at least partially surrounds in each case the peripheral edge (32) of the spring disc (20) from a circumferential side (48) of the spring disc (20), an upper side (50) of the spring disc (20) running transversely to the circumferential side (48), and a lower side (52) of the spring disc (20) that lies opposite the upper side (50).
  4. The temperature-dependent switching mechanism according to one of claims 1-3, wherein the peripheral edge (32) of the spring disc (20) is arranged so as to be clamped in the retaining ring (24).
  5. The temperature-dependent switching mechanism according to one of claims 1-4, wherein the main body (34) of the retaining ring (24) extends about a central axis (38) and defines a receptacle pocket (40) which is open towards the central axis (38) and in which the clamping element (36) and the peripheral edge (32) of the spring disc (20) are arranged.
  6. The temperature-dependent switching mechanism according to one of claims 1-5, wherein the main body (34) is configured in one piece.
  7. The temperature-dependent switching mechanism according to one of claims 1-6, wherein the bimetal disc (18) and the spring disc (20) are arranged on top of one another in a height direction (h), and wherein a height (H 1 ) of the contacting part (22) measured in the height direction (h) is larger than a height (H 2 ) of the retaining ring (24) measured in the height direction (h).
  8. The temperature-dependent switching mechanism according to one of claims 1-7, wherein the contacting part (22) is arranged so as to be centric relative to the retaining ring (24) and protrudes from the latter at least on a first side.
  9. The temperature-dependent switching mechanism according to one of claims 1-8, wherein an internal diameter (d 1 ) of the main body (34) of the retaining ring (24) is smaller than an external diameter (D 1 ) of the spring disc (20) but larger than an external diameter (D 2 ) of the bimetal disc (18).
  10. A temperature-dependent switch (10) having a temperature-dependent switching mechanism (12) according to one of claims 1-9 and a switch housing (46) surrounding the switching mechanism (12), wherein the temperature-dependent switching mechanism (12), as a function of its temperature, is configured to switch between a closed position in which the switching mechanism (12) establishes an electrically conducting connection between a first external terminal (14) and a second external terminal (16), and an open position in which the temperature-dependent switching mechanism (12) disconnects the electrically conducting connection.
  11. The temperature-dependent switch according to claim 10, wherein the switch housing (46) comprises a lower part (62), and a cover part (64) which is fastened to the lower part (62) and closes the lower part (62), wherein the lower part (62) and the cover part (64) are made of an electrically isolating material.
  12. The temperature-dependent switch according to claim 10 or 11, wherein the retaining ring (24) forms a first electrode (68), and wherein the lower part (62) supports the first electrode (68) and a second electrode (70) electrically connected to the second external terminal (16) and holds the two electrodes (68, 70) at a mutual spacing along a height direction (h), wherein the first electrode (68) is electrically connected to the first external terminal (14) by way of a line connection element (74) which is aligned transversely to the two electrodes (68, 70) and arranged in the lower part (62), and wherein the first and the second external terminal (14, 16) are led through the lower part (62) at the same height in terms of the height direction (h).
  13. The temperature-dependent switch according to claim 12, wherein the retaining ring (24) bears on the line connection element (74).
  14. The temperature-dependent switch according to one of claims 10 to 13, wherein the bimetal disc (18), as a function of its temperature, is configured to change its shape so as to switch the switching mechanism (12) between the closed position and the open position, and wherein the spring disc (20) in the closed position of the switching mechanism (12) is configured to establish the electrically conducting connection in which said spring disc (20) is supported on the retaining ring (24) and generates a mechanical contact pressure by way of which the contacting part (22) is pressed against a stationary mating contact (76).

Description

The present invention relates to a temperature-dependent switching mechanism for a temperature-dependent switch. The present invention further relates to a temperature-dependent switch with such a temperature-dependent switching mechanism. Temperature-dependent switches are already widely known. An example of a temperature-dependent switch is found in the... DE 10 2013 102 089 A1 revealed. Such temperature-dependent switches serve, in a manner known per se, 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 device to be protected influences the temperature of the switching mechanism located inside the switch. The switch is typically connected electrically in series with the supply circuit of the device to be protected via connecting leads, so that below the switch's response temperature, the supply current of the device to be protected flows through the switch. In the one from the DE 10 2013 102 089 A1 In a conventional switch, the switching mechanism is located inside the switch housing. The switch housing consists of two parts. It has a lower part made of electrically conductive material (e.g., metal), which is firmly connected to a cover part, also made of electrically conductive material (e.g., metal), with an insulating film in between. The temperature-dependent switching mechanism inside the switch housing includes a spring washer to which a movable contact is attached, and a bimetallic disc fitted over the movable contact. The spring washer presses the movable contact against a stationary mating contact located on the inside of the switch housing on the cover part. The outer edge of the spring washer rests against the lower part of the switch housing, allowing the electric current to flow from the lower part through the spring washer and the movable contact into the stationary mating contact and from there into the cover part. The temperature-dependent switching behavior of the switch is primarily due to the temperature-dependent bimetallic disc. This disc is usually designed as a multi-layered, active, sheet-like component consisting of two, three, or four interconnected components with different coefficients of thermal expansion. The bonding of the individual layers of metals or metal alloys in such bimetallic discs is usually material-bonded or form-fitted and is achieved, for example, by rolling. Such a bimetallic disk exhibits a first stable geometric configuration (low-temperature configuration) at low temperatures, below the response temperature of the bimetallic disk, and a second stable geometric configuration (high-temperature configuration) at high temperatures, above the response temperature of the bimetallic disk. The bimetallic disk switches from its low-temperature configuration to its high-temperature configuration depending on the temperature, following a hysteresis pattern. If the temperature of the bimetallic disc rises above its response temperature due to a temperature increase in the device being protected, the disc snaps from its low-temperature configuration to its high-temperature configuration. In this process, the bimetallic disc works against the spring disc in such a way that it lifts the moving contact part from the stationary counterpart contact, thus opening the switch and disconnecting the device being protected, preventing it from heating up further. Unless a reset lock is provided, the bimetallic disc snaps back into its low-temperature configuration, so that the switch closes again as soon as the temperature of the bimetallic disc drops below the so-called return temperature of the bimetallic disc as a result of the cooling of the device to be protected. In the one from the DE 10 2013 102 089 A1 In this well-known switch, the bimetallic disc in its low-temperature configuration is mechanically supported within the switch housing without any force being applied, and the bimetallic disc is not used to conduct the current. This has the advantage of a longer service life for the bimetallic disc, and the switching point, i.e., the response temperature of the bimetallic disc, remains unchanged even after many switching cycles. In many temperature-dependent switches, the bimetallic disc is therefore preferably inserted into the switch housing as a loose component during manufacturing. The bimetallic disc, for example, is fitted over the contact part attached to the spring washer, using a central through-hole provided in it. Only when the switch housing is closed is the bimetallic disc fixed in its position and its position relative to the other components of the switching mechanism determined. However, producing such a switch, in which the bimetallic disc is inserted separately, has proven cumbersome, as several steps are necessary to insert the switching mechanism into the switch housing. In one from the DE 10 2011