JPH0241850B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermal switch having a bimetallic snap disc and at least one snapping spring disc. Here, the term "thermal switch" refers to a switch equipped with a bimetallic disk that is installed in an electrical circuit and performs a switching operation based on a temperature change exceeding a critical point, and is particularly a temperature monitor.

One example of a switch of this type is described in German Patent No. 2121802. Another example of a switch of this kind is
It is described in No. 2916664. In DE 2511214, two corresponding switches are provided in one housing, one serving as a temperature regulator and one serving as a safety switch. All of these switches are equipped with a snapping spring disc to create contact pressure and conduct electricity in the closed position, so the bimetallic snap disc does not need to play the above role and is essentially It is only necessary to perform the switching operation. The bimetallic snap disk must in this case overcome the total contact pressure exerted by the snapping spring disk, in particular during separation of the switch contacts. Therefore, the bimetallic snap disk must generally have certain dimensions in order to be able to create a corresponding force. However, with the miniaturization of electrical components and equipment, there is a need for thermal switches of this type to be constructed as small as possible. In this case, the bimetallic snap disk also has to be retracted in known switches. Therefore, its operating capacity is reduced. Therefore,
The contact pressure exerted by the snapping spring disk must also be relatively small. Reducing the bimetallic snap disk also reduces its switching function and service frequency. Gold contacts can be used to reduce contact resistance, but gold contacts are expensive.

It is therefore an object of the present invention to overcome the above-mentioned drawbacks, and to obtain a high contact pressure and reliability while using a small bimetallic snap disc, similar to the use of a large bimetallic snap disc. An object of the present invention is to provide a heat-sensitive switch having high switching performance.

The purpose is to provide a thermal switch having a bimetallic snap disc and a snapping spring disc, in particular in a temperature sensing device, in which two preformed snapping spring discs are arranged to exert mutually opposite forces and one of the snapping spring discs is a bimetallic snap disc and one of the two snapping spring discs in the orientation;
a movable contact support portion arranged to be capable of supporting the other snapping spring disks in the opposite direction to the one direction, and the disks are arranged in a position apart from each other at a position apart from the contact device. This is achieved by a heat-sensitive switch, which is characterized in that it can be supported by stationary bearings arranged oppositely.

Snapping spring disks include those in which the direction of elastic force changes (reverses) at a certain position, and those in which the direction of elastic force does not change but have a maximum value or minimum value at a position where the elastic force is present.

Furthermore, "to support" includes the case of supporting the support part by directly contacting it, and the case of supporting the support part indirectly through another disk or member.

If the heat-sensitive switch is constructed according to the invention as described above, the bimetallic snap disk (hereinafter referred to as bimetallic disk) does not have to overcome the entire contact pressure exerted by the snapping spring disk, but at the switching point of the bimetallic disk. It is only necessary to overcome the pressing force minus the opposite force exerted by another snapping spring disc. Thus,
Since the contact pressure can be increased under conditions of the same dimensions, the switch according to the invention is particularly insensitive to vibrations, so that its field of use is essentially expanded. The thermal switch of the present invention has higher reliability than conventional switches even when the bimetallic disk size is reduced.

As mentioned above, by incorporating the snapping spring disks in opposite directions in the thermal switch,
The forces generated when the spring disc is displaced from its rest position are directed in opposite directions, at least at the time of switching the bimetallic disc. In this case, the two snapping spring discs are pressed so that no reversal of the direction of the forces appears in the course of their force action, that is, the forces are always directed in opposite directions when assembled in opposite directions. It is advantageous to mold it. In this case, of course, the rest position of one snapping spring disc is in the vicinity of one switch position of the thermal switch, and the rest position of another snapping spring disc is in the vicinity of the other switch position of the thermal switch. , the snapping spring disk does not reach its rest position due to its prestress. In the closed position of the heat-sensitive switch, if a force is applied from one snapping spring disk in a direction opposite to the pressing force of another snapping spring disk, this force in the opposite direction is absorbed by the bimetallic disk and produces a drive. All forces on the snapping spring disk are allowed to act before acting on the contact pressure. If the temperature changes beyond the rebound point of the bimetallic disc (e.g. from the closed circuit position), first the bimetallic disc no longer exerts a force on the drive snapping spring disc and therefore A situation arises in which the force of the bimetal disc acts against the snapping spring disc creating a contact pressure. In this case, the bimetal disc only has to overcome the difference in the mutually opposite forces of the two snapping spring discs in order to effect the switching of the thermosensitive switch. After switching, in the open position of the thermosensitive switch, the mutually opposite forces of the snapping spring disks essentially balance out at a low level. Therefore, the bimetallic disk only needs to apply a small force when restoring the equilibrium state and returning the thermal switch to the closed position.

The heat-sensitive switch according to the present invention can be arranged so that the positive side of the bimetal disk, that is, the side that expands more when the temperature rises, faces the contact fixed to the housing, or faces the opposite direction from the contact. For example, it can be used as a closed (normally open) switch or an open (normally closed) switch, ie, as a thermal switch that closes or opens when the ambient temperature rises above the rebound point of the bimetal disc.

In a preferred embodiment of the invention, the snapping spring disk reaches a force minimum after passing through the force maximum from each rest position, and the snapping spring disk forming the contact pressure is greater than the other spring disk. Configure it to have maximum power. In this case, of course, the maximum force of the second spring disk is
The contact pressure is selected to be greater than the minimum force of the first spring disk.

In a preferred embodiment of the thermal switch according to the invention, the disc is a circular disc shaped like a bowl. However, also within the scope of the invention are heat-sensitive switches in which the switch mechanism, ie a bimetallic disc and a snapping spring disc, is constructed as in the switch described in DE-A-2917557.

If the thermal switch is configured completely circular and the disk has a central opening into which the switch contact is inserted,
A particularly compact structure is obtained. If the switch contact knob can be fixed to the disk, at least one of the switch contact knobs
Two annular shoulders or collars are configured as a receiver for the disk. In this case, the disc fits loosely around the switch contact knob and is supported by an annular shoulder or collar on the knob. In a preferred arrangement, the switch mechanism is located within the housing. In this case, the diameter of the snapping spring disc located lower in the housing is smaller than the diameter of the other disc. This configuration eliminates the need for an undercut in the housing. Therefore, manufacturing becomes easy. By reducing the diameter of the disk located further down, the peripheral part of the wall of the housing around said disk can be constructed in the form of an annular shoulder and used as a receiver (stationary support) for another disk. can do. In a further embodiment of the thermal switch according to the invention, the snapping spring disc providing the contacting action is provided at the bottom of the housing. In this case, the outer circumferential edge of the spring disk abuts against the bottom of the housing as a receiver, and the inner circumferential edge abuts against the collar of the switch contact knob. On the other side of the collar of the switch contact knob there is first a bimetallic disc, on which a snapping spring disc rests, the inner edge of the spring disc abuts the switch contact knob. Furthermore, the snapping spring disk and the bimetallic disk are supported on an annular shoulder portion of the lid that projects inwardly from the housing periphery. Furthermore, when the bimetallic disc is moved into the closing position, it abuts another abutment opposite the shoulder portion. That is, a bimetallic disc has two opposing supports for its outer edge, thus
Bidirectional switching operations are possible, ie, opening and closing the thermal switch. If the second shoulder portion serving as a receiving surface is removed, the outer circumferential portion of the bimetallic disk only comes into contact with one receiving surface, so that a switching operation (generally, opening) can be performed only in one direction. In other words, the bimetallic disk can bounce freely in the opposite direction, so
No switching operations are performed in this direction. In order to enable manual re-closing of the switch in such cases, according to another preferred embodiment, the switch contact knob is provided with an actuating projection which can be actuated from the outside. This protrusion can protrude through a bore in the bottom of the housing of the thermal switch. If you push the protrusion inside, the switch will move to another position.

In conventional thermal switches, connecting wires configured as insulated connecting leads are soldered to the contacts of the switch, but this type of thermal switch must be inserted directly into the plate-like conductor of the printed circuit. Due to the preferred construction of the heat-sensitive switch according to the invention, relatively rigid metal connecting lugs can therefore be embedded in the housing part instead of the conventional soldered wires. To make an electrical contact from one connecting lug through the housing to the switch mechanism, depending on the preferred configuration, to another connecting lug,
A contact strip is provided which extends to the edge of the housing portion and is bent around said edge. In this case, electrical contact can be easily made by inserting the lid into the housing and bending the edges of the lid.

The invention will be explained in more detail below with reference to illustrated embodiments.

Temperature monitor 10 according to the present invention shown in FIG.
has a housing 12 that is generally made of metal (e.g. brass) and can be configured as a rotating member. A switch mechanism 10 is provided in the housing 12. The housing 12 is sealed in a fluid-tight manner by a lid 16 fitted onto the housing 12 and having connection lugs 18, 20 for electrical connection of the temperature monitor.

Switch mechanism 14 of temperature monitor 10 is connected to switch contact knob 28 by an opening in the illustrated embodiment.
It consists of two snapping spring disks 22, 24 and a bimetallic snap disk (bimetallic disk) 26 arranged concentrically around the .
The snapping spring disks are preformed in the shape of a bowl and are arranged in opposite directions within the switch. Switch contact knob 28 has an annular shoulder or collar 30 that serves as a receiver for snapping spring disks 22, 24 and bimetallic disk 26. In this case, the snapping spring disc 22 is located on one side of the collar 30, i.e.
It is provided on the side of the collar 30 opposite to the switch contact 32 fixed to the housing, while the snapping spring disc 24 and the bimetallic disc 2
6 is provided on the other side of the collar 30, ie on the side of the collar 30 facing the switch contact 32 fixed to the housing. Accordingly, snapping spring disk 22, snapping spring disk 24, and bimetallic disk 26 push switch contact knob 28 in opposite directions through collar 30, respectively.
For this purpose, outer supports for the disks 22, 24, 26 are provided in the housing 12. That is, the inner bottom surface 34 of the housing 12 serves as an outer receptacle for the snapping spring disk 22, and the lid 16 is recessed centrally from the inner edge of the housing.
The annular shoulder portion 36 serves as an outer support for the snapping spring disk 24 and the bimetallic disk 26 in one switching position. An inwardly directed annular shoulder 38 is provided at the periphery of the housing 12, opposite the shoulder 36.
This shoulder portion 38 serves as a receptacle for the bimetal disc 26 in the other switching state.

FIG. 1 shows one switch position of the thermal switch, ie, the open position. In this case, depending on the arrangement of the bimetallic disk 26, i.e. its positive side, i.e. the side on which the metal that expands more when heated is provided, faces towards the snapping spring disk 22, or alternatively it faces in the opposite direction. Depending on the orientation, the open circuit position will be a hot position or a cold position. The temperature monitor is, in the first case, an open-acting switch and, in the second case, a closing-acting switch.
That is, the temperature monitor opens or closes the circuit when the temperature exceeds a predetermined temperature.

An alternative switch position is shown in FIG.

First, the closing operation (normally open) switch will be explained.

If the temperature is below the rebound temperature of the bimetallic disk 26, the switch mechanism 14 will remain in the switch position of FIG. In this case, the forces of the snapping spring disks 22, 24 installed in opposite directions are essentially balanced, or, as the case may be, the force of the upper snapping spring disk 22 is The force in the opposite direction is slightly greater (in this case, the switch contact knob abuts the underside of the housing). In this case, the bimetal disk 26 is in a downwardly convex state and is completely unloaded.

As the temperature rises, the bimetallic disk 26
abuts the shoulder portion at its periphery and moves to pull the upper snapping spring disc 24 away from the collar 30. Lower snapping spring disk 22
is now released so that the switch contact knob 28 can be raised through the collar 30. When the bimetal disc 26 reaches the snapping point, it rebounds momentarily, and at this time, as a result of raising the upper snapping spring disc 24,
A lower snapping spring disc 22 allows the switch contact knob 28 to be raised into contact with a contact 32 fixed to the housing. in this case,
The switch is closed and assumes the position shown in FIG. The bimetallic disk 26 must overcome or compensate for the opposite residual force of the snapping spring disk 22 in the position of FIG. 2 so that the entire pressing force of the lower spring 22 is used to create the contact pressure. . As already mentioned, in the position of FIG. 1, the forces of both snapping spring disks 22, 24 are essentially balanced, so that the bimetallic disk 26
At the time of rebound, switching can be performed by applying an extremely small amount of force. In the position shown in FIG. 2, the bimetal disc 26 only needs to overcome the force of the upper weaker snapping spring disc 24, and the contact pressure is created by the force of the lower stronger snapping spring disc 22. be done.

When the temperature falls, the center portion of the bimetal disk 26 descends again. As long as the bimetal disc 26 is not in contact with the collar 30, the contact pressure is kept constant by the lower snapping spring disc 22. When the bimetallic disc 26 reaches the snapping point, it rebounds downward and cooperates with the force of the upper snapping spring disc 24 to overcome the pressing force of the lower snapping spring disc 22 and break contact. The switch again assumes the open position of FIG.

That is, when transitioning from the open circuit position shown in FIG. 1 to the closed circuit position shown in FIG.
In order to break the equilibrium state of both snapping spring disks in the open position shown, it is sufficient to apply a minimum force in the closing direction at the rebound point. Second
In the closed circuit position shown in the figure, the bimetal disc 26 cancels out the residual force of the upper snapping spring disc 24 in the above position, so that the entire spring force of the lower snapping spring disc 22 acts as contact pressure. When moving from the closed circuit position shown in Figure 2 to the open circuit position shown in Figure 1, the bimetal disc 26
need only overcome the difference in mutually opposing forces between the lower snapping spring disc 22 and the upper snapping spring disc 24, and need not overcome the entire pressing force of the lower snapping spring disc 22.

Instead of the snapping spring disc used in the embodiments of Figures 1 and 2, which exerts a force always directed in opposite directions and varying over its path of motion, due to its inherent stress, It is also possible to use snapping spring discs, which bounce at specific points in the path of motion and change the direction of the force.
In this case, the snapping spring disk must be held against both sides of the switch contact knob, and an annular shoulder or collar must therefore be additionally installed.

If the bimetallic disk 26 is installed in the housing in reverse, i.e., with the positive side, i.e., the metal side that expands more when the temperature rises, pointing downward instead of upward, the thermal switch can be used as a closed (normally open) switch. Work as.

The closing operation switch will be described below with reference to FIGS. 1 and 2.

Starting from FIG. 2, which shows the switch position of the temperature monitor below the switching temperature. The bimetal disk 26 is in an upwardly convex state. In this case, the bimetal disc 26 pushes the upper weaker snapping spring disc 24 and raises it slightly, so that no pressure is applied from above to the collar 30 of the switch contact knob. Therefore, the full force of the lower snapping spring disc 22 presses the switch contact knob 28 through the collar or shoulder portion 30 against the contact 32 fixed to the housing, thus creating an optimum contact pressure.

When the temperature is increased, the central part of the bimetallic disc 26 is lowered while the contact pressure is kept constant by the lower snapping spring disc 22. When the bimetal disc 26 reaches the snapping point, it rebounds and the upper snapping spring disc 2
4 exerts a force counteracting the force of the lower snapping spring disk 22. At this time, the resultant force of the force of the upper snapping spring disk 24 and the force of the bimetallic disk 26 at the rebound point is greater than the force of the lower snapping spring disk 22, so the contact opens and the temperature monitor is activated as shown in FIG. Move to position.

During cooling, the bimetal disc 26 rebounds again and the upper snapping spring disc 24
The lower snapping spring disc 22 is released by pressing , so that the full maximum force of this spring disc 22 is utilized to create the contact pressure. In this case, the switch again assumes the position of FIG.

In the closed position of FIG. 2, the snapping spring disk 22 creates a contact pressure of approximately 38.5 kg. At the rebound point of the bimetallic disc 26, the upper spring disc 24 has a force of approximately 18.1 Kg, while the lower spring disc 22 has a force of approximately 38.5 Kg. Therefore,
Bimetallic disc 26 only needs to exert approximately 20.4 kg of force to switch from the closed position of FIG. 2 to the open position of FIG. 1. In the open circuit position shown in Figure 1,
Both snapping spring disks 22, 24 are
Maintains equilibrium at a force of approximately 13Kg.

3 and 4 show another embodiment of the temperature monitor according to the present invention. In the embodiments shown in FIGS. 1 and 2, switching operations are performed when the temperature rises or falls above the rebound point of the bimetal disk, but the switches shown in FIGS. If you cross it, it will open automatically, but
It does not close automatically in the opposite direction. This switch must be closed manually. This type of switch is used as an open-acting (normally closed) switch, ie it is closed at low temperatures, opens when the bimetallic disc exceeds the rebound temperature, but does not close when cooled again.

Identical parts of the switch are designated by the same reference numerals. In the embodiment shown in FIGS. 3 and 4, there is no support 38 (see FIGS. 1 and 2) consisting of an annular shoulder portion, so that once the circuit is opened, it cannot be closed again. That is, even when the bimetal disk 26 returns from the shape shown in FIG. 3 to the shape shown in FIG.
6 is unable to release the snapping spring disk 22 from a force equal to or somewhat greater than the force in the FIG. 3 position of the snapping spring disk 24, and therefore from the FIG. 3 position to the FIG. 4 contact position. switching is not performed.

Resetting from the contact position of FIG. 3 to the position of FIG. 4 must be done manually, if necessary. For this reason, the bottom 40 of the housing 12 includes:
An opening is provided through which the projection 42 of the switch contact knob 28 projects. When it is desired to reset from the state shown in FIG. 3 to the state shown in FIG. 4, the projection 42 is pushed from the outside to bring the switch contact knob 28 into contact with the contact 32 fixed to the housing. In this position, the snapping spring disk 22 again exerts maximum force and is able to maintain this position. In this case, of course, the bimetallic disk 26 assumes the recoil position of FIG.

The switching characteristics of the monitor of FIGS. 3 and 4 when transitioning from the contact position of FIG. 4 to the position of FIG. 3 are the same as those described with reference to FIGS. 1 and 2.

The graph of FIG. 5 shows the force-stroke curves of both snapping spring discs 22, 24.
In this case, both snapping spring discs 2
2 and 24 are displaced in opposite directions from the rest position. That is, the rest position of the snapping spring disk 22 is on the left side of the graph of FIG. 5, and the rest position of the snapping spring disk 24 is on the right side. As can be seen from the force curves, if the disks are placed in opposite directions within the temperature monitor, the forces are opposed to each other. Each snapping spring disc first passes through a local maximum and then through a local minimum. (Transition from left to right for disk 22 and from right to left for disk 24. In this case, the force on disk 24 is directed in the opposite direction and the resultant force is therefore given by the difference, since both The forces are plotted in the same quadrant for simplicity and comparison.)
In the position of FIG. 2, the disk is at the location shown as "F1G.2" in FIG. The snapping spring disc 22 is at a point of maximum force and therefore exerts maximum force on the contact. The snapping spring disc 24 is in the opposite direction with respect to this disc at the point mentioned above and the snapping spring disc 24
Bimetal disk 2 that acts in the same direction as
It is held in equilibrium by a force of 6.

In Figure 5, the location in Figure 1 is also shown as "F1G.1". In this case, the edge of the bimetal disk 26 is
It is completely free (Fig. 1) and is therefore not subject to any forces. In transitioning from the position of FIG. 2 to the position of FIG. 1, bimetallic disc 26 first cooperates with the force of snapping spring disc 24 to overcome the drag force of snapping spring disc 22, so that A point is reached where operation begins, and then a no-force condition (FIG. 1) is reached. When moving from the position shown in Figure 1 to the position shown in Figure 2,
The bimetallic disc 26 only needs to change the force equilibrium between both snapping spring discs in the direction in which the snapping spring disc 22 prevails, and then a state where the force of the snapping spring disc 22 is canceled out ( Figure 2) is reached. The force-stroke curve is not linear and has force peaks.

As mentioned above, unlike a normal temperature monitor in which connecting wires are soldered, connection lugs 18 and 20 are cast and embedded in the lid 16 of the housing 12 of the temperature monitor 10. In the arrangement according to the invention, the connecting lug 18 has a wide central part arranged in the middle of the lid 16 essentially above the movable contact part 28 . The lid 16 is provided with a connecting tab 52 that projects essentially horizontally from the central portion 50. The further connecting lug 20 is essentially T-shaped. That is, the connection tab 54 of the connection lug 20
protrudes from the lid 16 diametrically opposite the connecting tab 52 and is provided at its recessed end with a contact strip 56 extending at right angles to the connecting tab 54. Connection lug 18, 20
is embedded in the lid 16 as shown in FIG. The connecting lugs 18, 20 may also consist of sections of a grid if the lid 16 with connecting lugs is produced in large quantities. In this case, the connecting lugs 18, 20 are
After casting and hardening, it is cut to the desired length, similar to contact strip 56. The connecting tabs 52, 54 of the connecting lugs 18, 20 are folded upwardly from the lid, while the contact strip 56 is folded around the lid 58, 60 (FIGS. 6, 8). Contacts 32 are optionally welded to the plate-like part 50 inside the lid. When the lid 16 is then inserted into the housing 12 of the temperature monitor 10, the central portion 50 with welded contacts 32 will be located above the switch contact knob 28, while the bent end of the contact strip 56 will be located above the switch contact knob 28. contacts the housing 12; In the closed position of FIG. 2, from the connecting lug 18, its extended portion 50,
An electrical path is made through the contacts 32, the switch contact knob 28, the snapping spring disc 22, the housing 12 and the ends of the contact strip 56 to the tab 52 of the connecting lug 20.

Although the invention has been described with reference to an embodiment of a temperature monitor with a circular housing and a circular snapping disc (disc spring), within the framework of the invention it is possible to use other configurations (e.g. long snapping discs, edge discs). Partially cut bimetallic snap discs and rectangular housings) are also possible. In this case, for example, the connecting elements or connecting lugs can also be pulled out from the side.

According to the heat-sensitive disk of the present invention, the bimetal snap disk does not require a large operating force during switching operation by operating against the difference in elasticity between the two snapping spring disks. On the other hand, when the contact is in the closed position, a large contact pressure can be obtained due to the elastic force of the snapping spring disk, so the size of the bimetal snap disk can be reduced in relation to its operating capacity as a heat-sensitive switch, and the device We were able to provide a heat-sensitive switch that is easy to incorporate into the system.

Furthermore, when the dimensions of the bimetallic snap disc are the same, the thermal switch according to the present invention
Since the snapping spring disk can be made larger, and therefore the contact pressure of the contacts can be increased, a heat-sensitive switch can be made that is particularly less susceptible to vibrations, and its reliability is improved.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an embodiment of the thermal switch according to the present invention as a temperature monitor in an open state, and FIG. 2 is a diagram of the temperature monitor of FIG. 1 in a closed state.
FIG. 3 is a drawing showing another embodiment of the monitor according to the invention in an open circuit state, FIG. 4 is a drawing of the embodiment of FIG. 3 in a closed circuit state, and FIG. FIG. 6 is a drawing showing the lid of the temperature monitor according to the invention under construction; FIG. Sectional view of the lid in Figure 6, No. 8
The figure is a view similar to FIG. 6 of the lid after the connecting lugs and contact strips have been folded upwards. 10...Temperature monitor, 12...Housing, 1
4... Switch mechanism, 16... Lid, 18; 20...
...Connection lug, 22; 24...Snapping spring disk (spring disk), 26...Bimetal snap disk (bimetal disk), 28...
...Switch contact knob, 32...Contact.

Claims (1)

[Scope of Claims] 1. A thermal switch having a bimetallic snap disc and a snapping spring disc, comprising: two preformed snapping spring discs arranged to exert forces in opposite directions to each other; a bimetal snap disc and one of the snapping spring discs,
a movable contact support portion arranged to be capable of supporting the other snapping spring disks in the opposite direction to the one direction, and the disks are arranged in a position apart from each other at a position apart from the contact device. A heat-sensitive switch characterized in that it can be supported by stationary support parts arranged opposite to each other. 2. The snapping spring disk passes through a maximum point of force from its rest position and then passes through a minimum point of force, and the snapping spring disk forming the contact pressure is larger than another snapping spring disk. 2. The thermal switch according to claim 1, wherein the thermal switch has a maximum point of force. 3. Claim 1, wherein the bimetal snap disc and the snapping spring disc are circular discs shaped into a bowl shape.
The heat-sensitive switch according to item 1 or 2. 4. The thermal switch of claim 3, wherein each disc has a central opening for receiving a switch contact. 5 As the support part on the center side of the disk,
5. The thermal switch of claim 4, wherein at least one annular shoulder or collar is formed on the switch contact knob. 6. characterized in that said bimetallic snapping disk is arranged on the same side of the collar as the weaker snapping disk spring, while another snapping spring disk is arranged on the other side of the collar. A heat-sensitive switch according to claim 5. 7. Claims 5 or 6, characterized in that an outer bearing part is disposed at the outer edge of each of the disks and is arranged in relation to the central bearing part and configured as the stationary bearing part. Thermal switch described in section. 8. Claim 7, wherein the switch mechanism is provided in a housing, and the diameter of the snapping spring disk disposed lower in the housing is smaller than the diameter of the other disks. Thermal switch described. 9 A snapping spring disk 22 forming a contact pressure is arranged at the bottom of the housing 12, the outer circumferential edge of the snapping spring disk 22 forming a contact pressure on the housing 12 as a stationary bearing.
and the inner circumferential edge of the one snapping spring disc 22 abuts against the collar 30 of the switch contact knob 28 serving as the support part, and on the other side of the collar 30 of the switch contact knob 28, First, the bimetal snap disk 26 is placed, and then another snap spring disk 24 is placed on top of the bimetal snap disk 26 in contact with its inner edge, and the other snap disk 24 and the bimetal snap disk Claim 8, characterized in that the snap disk (26) projects inwardly from the periphery of the housing (12) and is supported on an annular shoulder portion (36) of the lid (16) which is configured as one of the stationary bearings. Thermal switch described. 10. The heat-sensitive device according to claim 1, wherein the switch contact knob 28, which is configured as a part of a movable contact, is provided with an actuating protrusion 42 that can be actuated from the outside. Switch. 11. Claim characterized in that, in order to transfer the bimetallic snap disc 26 into the closing position, a bearing 38 is provided opposite the shoulder part 36 and configured as another of the stationary bearings. 9. The heat-sensitive switch according to item 9. 12. A thermal switch according to claim 1, characterized in that the housing part 16 has a relatively rigid metal connecting lug embedded therein. 13. The inner end 50 of the connecting lug 18 extends inwardly and is exposed to the range of movement of the switch contact knob 28.
Thermal switch described in section. 14 Another connecting lug 20 is connected to the housing part 16
14. A thermal switch as claimed in claim 12 or claim 13, characterized in that it has a contact slip (56) extending up to the edge and folded around said edge. 15 Connection tabs 52, 54 of connection lugs 18, 20
15. A thermal switch according to claim 12, characterized in that the housings (12, 16) extend perpendicularly and mutually parallel.