EP3809437A1 - Temperature-dependent switch - Google Patents

Abstract

Temperature-dependent switch (10) which has a first and a second stationary contact (48, 50) and a temperature-dependent switching mechanism (14) with a movable contact member (42). In its first switching position, the switching mechanism (14) presses the contact member (42) against the first contact (48) and creates an electrically conductive connection between the two contacts (48, 50) via the contact member (42). In its second switching position, the switching mechanism (14) keeps the contact member (42) at a distance from the first contact (48) and thus interrupts the electrically conductive connection between the two contacts (48, 50). The temperature-dependent switching mechanism (14) has a temperature-dependent snap part (30). Snapping the temperature-dependent snap part (30) from its geometric low-temperature configuration to its geometric high-temperature configuration brings the switching mechanism (14) from its first switch position to its second switch position and thus opens the switch (10). A locking device (52) prevents the switch (10), which has been opened, from being closed again by holding the switching mechanism (14) in its second switch position as soon as it is activated. The closing lock (52) has a temperature-dependent anchor element (54) and a counter-holder (56) which interacts with the anchor element (54) and has an opening (58). The armature element (54) is designed to change its shape when an armature switching temperature is exceeded from a first shape in which the armature element fits through the opening (58) to a second shape in which the armature element (54) no longer passes through the Opening (58) fits to change.

Description

The present invention relates to a temperature-dependent switch which has a first and a second stationary contact and a temperature-dependent switching mechanism with a movable contact member. In its first switching position, the switching mechanism presses the contact element against the first contact and, via the contact element, establishes an electrically conductive connection between the two contacts. In its second switching position, the switching mechanism keeps the contact member at a distance from the first contact and thus interrupts the electrically conductive connection between the two contacts. The temperature-dependent switching mechanism has a temperature-dependent snap part which, when a switching temperature is exceeded, snaps from its geometric low-temperature configuration to its geometric high-temperature configuration and, when the switch-back temperature is subsequently fallen below, snaps back from its geometric high-temperature configuration to its geometric low-temperature configuration. Snapping the temperature-dependent snap part from its geometric low-temperature configuration to its geometric high-temperature configuration brings the switching mechanism from its first switch position to its second switch position and thus opens the switch. In the switch according to the invention, a locking lock is also provided, which prevents the open switch from being closed again by holding the switching mechanism in its second switch position as soon as it is activated.

A generic switch is already from the DE 10 2018 100 890 B3 known.

Such temperature-dependent switches are used in a known manner to protect electrical devices from overheating. For this purpose, the switch is electrically connected in series with the device to be protected and its supply voltage and is mechanically arranged on the device in such a way that it is in thermal connection with it.

A temperature-dependent switching mechanism ensures that the two stationary contacts of the switch are electrically connected to one another below the response temperature of the switching mechanism are connected. Thus, the circuit is closed below the response temperature and the load current of the device to be protected can flow through the switch.

If the temperature rises above a permissible value, the switching mechanism lifts the movable contact element from the mating contact, whereby the switch is opened and the load current of the device to be protected is interrupted. The now de-energized device can then cool down again. The switch that is thermally coupled to the device also cools down again and would then actually close again automatically.

The one from the DE 10 2018 100 890 B3 known switch, however, a locking mechanism ensures that this switching back does not take place in the cooling position, so that the device to be protected cannot switch itself on again automatically after it has been switched off. The locking device locks the switching mechanism mechanically so that the switching mechanism cannot close again after it has been opened once, even if there are strong vibrations or temperature fluctuations.

This is a safety function that applies, for example, to electric motors that are used as drive units. This is intended in particular to avoid damage to the device or even injury to the person using the device.

Due to their switching behavior, switches of this type, which do not close again after being opened once, are also referred to as single-use switches.

It goes without saying that "opening" the switch is understood to mean the interruption of the electrically conductive connection between the two contacts of the switch and not an opening of the switch housing in the mechanical sense.

Another switch of this type is from the DE 10 2013 101 392 A1 known. This switch has a temperature-dependent switching mechanism with a temperature-dependent bimetal snap-action disk and a bistable spring disk which carries a movable contact or a current transmission element. When the bimetal snap disk is on a temperature above its response temperature is heated, it lifts the contact or the current transmission element against the force of the spring washer from the mating contact or contacts and thereby pushes the spring washer into its second stable configuration in which the switching mechanism is in its high-temperature position.

If the switch and thus the bimetal snap disk cool down again, it jumps back into its low temperature position. Due to the design, however, its edge cannot be supported on a counter bearing, so that the spring washer remains in the stable second configuration in which the switch is open.

After opening the switch once, it remains in its open position, even if it cools down again. However, attempts at the applicant's company have shown that the DE 10 2013 101 392 A1 known switch closes again in the event of strong mechanical vibrations, so that it may not be optimally usable from a safety perspective in some applications.

It is also known to provide such temperature-dependent switches with a so-called self-holding resistor, which is connected in parallel to the two mating contacts, so that it takes over part of the load current when the switch opens. Ohmic heat is then generated in this self-holding resistor, which is sufficient to keep the snap disk above its response temperature.

This so-called self-holding is only active as long as the electrical device is still switched on. As soon as the device is switched off from the supply circuit, no more current flows through the temperature-dependent switch, so that the self-holding function is no longer applicable. When the electrical device is switched on again, the switch would therefore be in the closed state again, so that the device can heat up again, which could lead to consequential damage.

This problem arises from the DE 10 2007 042 188 B3 and the DE 10 2013 101 392 A1 Avoid known switches in which the self-holding function is not implemented electrically, but by a bistable spring part, which is temperature-independent has two stable geometric configurations, as described in the publications cited above.

In contrast to this, the snap-action disk is a bistable snap-action disk which, depending on the temperature, assumes either a high-temperature configuration or a low-temperature configuration.

With the ones mentioned at the beginning DE 10 2007 042 188 B3 the spring washer is a circular spring snap-action disk to which the contact member is attached in the middle. The contact member is, for example, a movable contact part which is pressed by the spring snap-action disk against the first stationary contact which is arranged on the inside on a cover of the housing of the known switch. With its edge, the spring snap-action disk is pressed against an inner base of a lower part of the housing, which acts as a second contact. In this way, the self-electrically conductive spring snap-action disk creates an electrically conductive connection between the two mating contacts.

In its low-temperature position, the bimetal snap disk lies loosely on the contact part. If the temperature of the bimetal snap disk increases, it jumps to its high temperature position, in which it presses with its edge on the inside of the upper part of the housing and with its center presses on the spring snap disk in such a way that it moves from its first into their second stable configuration jumps, whereby the movable contact part is lifted from the stationary contact and the switch is opened.

When the temperature of the switch cools down again, the bimetal snap-action disk jumps back to its low-temperature position. It comes with its edge in contact with the edge of the spring snap disk and with its center in contact with the upper part of the housing. However, the actuating force of the bimetal snap disk is not sufficient to allow the spring snap disk to jump back into its first configuration.

Only when the switch cools down does the bimetallic snap disk bend further, so that it can finally press the edge of the spring snap disk so far down onto the inner bottom of the lower part that the spring snap disk springs back into its first configuration and the switch closes again.

The one from the DE 10 2007 042 188 B3 Known switch remains open after a single opening until it has cooled to a temperature below room temperature, for which purpose a cold spray can be used, for example.

Although this switch meets the corresponding safety requirements in many applications, it has been found that the tensioning of the bimetal snap disk between the upper part of the housing and the edge of the spring snap disk in rare cases causes the spring snap disk to spring back unintentionally.

From the DE 10 2013 101 392 A1 It is also known to use a current transmission element, for example in the form of a contact plate, which is carried by the spring snap-action disk, as the movable contact element. Both stationary contacts are now arranged on the inside of the cover of the housing, an electrically conductive connection being established between these two contacts by the contact plate making contact.

In this switch, the spring snap disk is fixed with its edge on the lower part of the housing, while the bimetallic snap disk is provided between the spring snap disk and the inner bottom of the lower part.

Below the response temperature of the bimetal snap disk, the spring snap disk presses the contact plate against the two stationary contacts. If the bimetal snap disk jumps to its high temperature position, its edge presses against the spring snap disk and its center pulls the spring snap disk away from the upper part, so that the contact plate is out of contact with the two mating contacts. So that this is geometrically possible, contact plates are Spring snap disk and bimetal snap disk are captively connected to one another by a centrally running rivet.

When the temperature of the bimetal snap disk drops again, it jumps back into its low temperature position, but the spring disk remains in its assumed configuration, since the bimetal snap disk lacks a counter bearing for its edge, so that the current transmission element does not again against the two can press stationary contacts.

Due to its design, this switch therefore has a self-holding function. In the event of strong mechanical vibrations, however, in rare cases, the spring snap-action disk can also spring back unintentionally.

From the DE 25 44 201 A1 Furthermore, a temperature-dependent switch with a current transmission element designed as a contact bridge is known, in which the contact bridge is pressed against two stationary mating contacts via a closing spring. The contact bridge is in contact with a temperature-dependent switching mechanism via an actuating bolt, which consists of a bimetallic snap disk and a spring washer, both of which are clamped at their edge.

As with the one from the DE 10 2007 042 188 B3 Known switches, the spring washer and the bimetal snap disk are both bistable in this switch, the bimetal snap disk in a temperature-dependent manner and the spring washer in a temperature-independent manner.

If the temperature of the bimetal snap disk increases, it presses the spring washer into its second configuration, in which it presses the actuating bolt against the contact bridge and lifts it against the force of the closing spring from the stationary mating contacts.

Even when the bimetal snap disk cools down, the spring disk remains in this second configuration and keeps the known switch open against the force of the closing spring.

From the outside, pressure can now be exerted on the contact bridge with a button, so that the spring washer is pushed back into its first stable configuration via the actuating bolt.

In addition to the very complex construction, this switch has the disadvantage that, in the open state, the spring washer lifts the contact bridge against the force of the closing spring from the mating contacts, so that the spring washer in its second configuration must reliably overcome the force of the closing spring. However, because the closing spring ensures that the contact bridge rests securely on the mating contacts in the closed state, a spring washer with very high stability is required in the second configuration.

Another switch with three switch positions is from the DE 86 25 999 U1 known. In this known switch, a spring tongue clamped in on one side is provided, which at its free end carries a movable contact part which cooperates with a fixed counter-contact.

A dome is formed on this spring tongue, which is pressed into its second configuration by a bimetal plate also fastened to the spring tongue, in which it spaces the movable contact part from the stationary mating contact.

With this switch, the dome must hold the movable contact part at a distance from the fixed mating contact against the closing force of the spring tongue clamped on one side, so that the dome in its second configuration has to apply a high actuating force.

The known switch thus has the disadvantages already discussed above, namely that high actuating forces have to be overcome, which leads to high production costs and an unsafe state in the cooling position.

The one from the aforementioned DE 10 2018 100 890 B3 Known switch has the most mechanically stable locking device compared to the other switches mentioned. Due to the mechanical locking of the switching mechanism, which is effected by the locking device, accidental downshifting after the switch has been opened is almost impossible.

However, it has been shown that the DE 10 2018 100 890 B3 known locking device is relatively complex to manufacture, so that the production costs of the switch are comparatively high.

Against this background, the present invention is based on the object of developing the switch mentioned at the beginning in such a way that it has an alternative locking device that is simple and therefore inexpensive to manufacture and yet reliably interrupts the circuit even when the switch is in the cool position and in the event of strong vibrations is guaranteed.

According to the invention, this object is achieved in a switch of the type mentioned in that the closing lock has a temperature-dependent armature element and a counter-holder that interacts with the armature element and has an opening, the armature element being designed to change its shape from a first when an armature switching temperature is exceeded Form in which the anchor element fits through the opening, so that the closing lock is not activated, to change into a second form in which the anchor element no longer fits through the opening, so that the closing lock is activated.

The locking lock according to the invention is therefore a temperature-dependent locking lock that is activated when the armature switching temperature is reached or exceeded. As long as the armature switching temperature is not reached or exceeded, the locking device is not activated.

The locking lock according to the invention uses an anchor element which cooperates with a counter holder which has an opening. The anchor element is set up to his Change shape depending on the temperature. More precisely, the armature element changes its shape when a predefined temperature is reached or exceeded, which is referred to here as the armature switching temperature. Below the armature switching temperature, the armature element has a first shape in which the armature element fits through the opening in the counter holder. As long as the armature switching temperature is not reached, the armature element can be moved through the opening with respect to the counterholder, so that the armature element does not engage with the counterholder and the locking device is therefore not activated. As soon as the armature switching temperature is reached or exceeded, the armature element changes its shape into a second shape in such a way that it no longer fits through the opening in the counter holder. The anchor element then latches with the counter holder and can then no longer move relative to this at least in one direction. The then blocked direction of movement of the armature element prevents the switching mechanism from being switched back from the second, open switching position to the first, closed switching position.

According to the definition according to the invention, the change in shape of the armature element takes place when the armature switching temperature is “exceeded”. In principle, the change in shape already takes place when the armature switching temperature is reached. The word "exceeding" is intended to clarify at this point, however, that the change in shape of the armature element after a warming-up process, i.e. when the armature switching temperature is reached, takes place starting from a lower temperature and not during a cooling process when the armature switching temperature is reached starting from a higher temperature.

The anchor element can, for example, be configured to change its shape from the first shape to the second shape when the armature switching temperature is reached during a warm-up process, but to retain its second shape when the armature switching temperature is subsequently reached again during a cooling process.

The change in shape that the armature element makes when the armature switching temperature is exceeded can be varied. For example, the anchor element can change its shape from a convex to a concave shape or vice versa. It is also conceivable that the anchor element expands in one direction and tapers in another direction. More complex changes in shape are also conceivable.

The anchor element is preferably designed to mechanically lock the switching mechanism in its second switching position when the anchor element has its second shape.

The locking device according to the invention locks the switchgear so similar to that from the DE 10 2018 100 890 B3 known switch, so that the switch can not close again after opening it once and after activating the locking device, even if strong mechanical vibrations occur. By locking the temperature-dependent switch, the switch is consequently also locked, which is used synonymously in the context of the present invention.

The switch according to the invention is thus prevented from switching back as soon as the locking lock is activated, i.e. as soon as the switching mechanism is in its second switching position and the armature element has its second shape in which it interacts with the counter-holder. If the lock is activated, the switch can no longer be closed even if the switch-back temperature is not reached after it has been opened. It is true that the temperature-dependent snap part tries to snap back into its geometric low-temperature configuration when the switch-back temperature is fallen below and to restore the electrically conductive connection between the two contacts. However, this is prevented by the locking device. More precisely, the described interaction of the armature element with the counter-holder generates a counterforce which counteracts the closing force generated by the temperature-dependent snap part and prevents the switch from being switched back, i.e. closing the switch after it has opened.

In contrast to the one from the DE 10 2018 100 890 B3 known switch, the switch according to the invention has the advantage that the change in shape of the armature element and thus the locking device can be designed reversibly. However, it is understood that Such a reversible configuration of the locking lock is only an optional feature in the present case.

According to one embodiment, the armature element can be configured to change its shape from the second shape to the first shape when the armature reset temperature is undershot, the armature reset temperature being lower than the armature switching temperature.

The armature element can be designed, for example, in such a way that the armature reset temperature is very low, that is, for example, in a temperature range below room temperature. The lock could then be released again by treating the switch with the appropriate cold.

According to a preferred embodiment, the anchor element has a bimetal part. This bimetal part can bring about the described change in shape of the anchor element.

The advantage of using a bimetal part to bring about the change in shape of the anchor element is that bimetal parts can bring about such changes in shape at switching temperatures that can be set very precisely. In addition, these are relatively inexpensive components, which nevertheless have a very high technical reliability with regard to their switching behavior. Likewise, with such a bimetal part, the change in shape of the anchor element can be designed reversibly, so that the locking lock, once activated, can also be deactivated again.

Something similar can also be achieved by using a shape memory alloy instead of a bimetal part. According to an alternative embodiment, it is therefore provided that the anchor element has a component made from a shape memory alloy (memory metal). In principle, it is also possible to combine a bimetal part with a component made of a shape memory alloy in the anchor element.

If an irreversible locking device is desired, the shape memory alloy can be a shape memory alloy with a one-way memory effect. In this case it acts The switch according to the invention is a so-called one-time switch. The shape memory alloy only allows a one-time change in shape of the anchor element. After it has changed its shape from the first shape to the second when the armature switching temperature is exceeded, renewed cooling does not cause a new shape change in such a shape memory alloy with a one-way effect.

Alternatively, the shape memory alloy can be a shape memory alloy with a two-way memory effect. The switch is then a switch with a locking device, which is designed to be reversible, that is to say can be released again. Shape memory alloys with a two-way effect can, so to speak, remember two shapes - one at high and one at low temperature. With such a two-way shape memory alloy, the armature can change its shape from the first shape to the second shape when the armature switching temperature is reached and, when it cools down, it can take on its first shape again as soon as the armature reset temperature is reached.

In one embodiment, the switch also has a housing, wherein either the armature element is arranged or fastened to a part of the switching mechanism and the counter holder is arranged or fastened to the housing, or, alternatively, the counter holder is arranged on the part of the switching mechanism or is attached and the anchor element is arranged or attached to the housing.

In other words, according to this embodiment, the anchor element is either arranged or fastened on the housing or arranged or fastened on a part of the switching mechanism. The counter holder is accordingly arranged or fastened to the other part (either to the part of the switching mechanism or to the housing).

By activating the locking lock, according to this embodiment, through the interaction of the armature with the counter-holder, part of the switching mechanism is coupled to the housing in its second switching position or is locked on it. In order to achieve this locking function, it is basically irrelevant which of the two components (anchor element or counter bracket) is arranged on the switching mechanism and which of the two components is arranged on the housing. In both cases, a mechanically stable locking lock is produced via the anchor element and the counter-holder, which locks the switching mechanism in its second switching position on the housing by mechanical fastening or locking.

Preferably said part of the switching mechanism on which the armature element or the counter holder is arranged or fastened is the movable contact member.

The movable contact member is particularly well suited as a component of the switching mechanism on which the anchor element or the counter holder can be arranged or fastened. The moving contact member is usually the structurally most stable component of the switching mechanism. The anchor element or the counter holder can be attached to it in a materially bonded manner, for example by welding, soldering or gluing. As an alternative to this, the anchor element or the counter holder can also be formed integrally, that is to say in one piece, with the movable contact member. This has the advantage of further mechanical stabilization of the locking device.

According to a further embodiment, it is provided that the anchor element is arranged in the first switching position of the switching mechanism at least partially in the opening or on a first side of the counter-holder, and that the anchor element is inserted through the opening in the second switching position of the switching mechanism and on a the first side opposite the second side of the counter holder is arranged.

During the switching process of the switch, in which the temperature-dependent snap part snaps over from its geometric low-temperature configuration to its geometric high-temperature configuration, the anchor element is thus pushed through the opening in the counter holder. If the armature switching temperature is exceeded during or after the switching process, the armature element assumes its second shape in which it no longer fits through the opening. The lock is then activated. This remains activated until the anchor element assumes its first shape again, which, as mentioned above, does not necessarily have to be the case. As long as the anchor element remains inserted through the opening on the second side of the counter holder.

According to a further embodiment, the counter holder has an essentially plate-shaped element with a hole that forms the opening.

This refinement has the advantage that such a plate-shaped element with a hole can be produced relatively easily and inexpensively and can just as easily be mounted on the switching mechanism or on the housing. The anchor element and counter holder then work together in the manner of an anchor with a perforated plate in which the anchor engages.

According to a further embodiment, it is provided that the armature switching temperature is equal to or higher than the switching temperature of the temperature-dependent snap part.

If the two switching temperatures are selected to be the same, the locking device is activated at the same time as the switch opens. If, on the other hand, the armature switching temperature is selected to be higher than the switching temperature of the temperature-dependent snap part, the locking device is only activated after the switch has been opened. The circuit is interrupted when the switch is opened. In practice, however, the switch usually cools down a little before the cooling process begins due to the residual heat typically remaining in the device to be protected. The temperature swings a bit after opening the switch, which is why we speak of the so-called overshoot temperature range. It is therefore possible to set the armature switching temperature in this overshoot temperature range.

According to a further embodiment, it is provided that the armature reset temperature is lower than the reset temperature of the temperature-dependent snap part.

This has the advantage that if the switch cools down regularly after it has been opened, the locking lock remains activated even when the switch-back temperature of the temperature-dependent snap part is reached or fallen below. Deactivation of the locking lock (if it is designed to be reversible) can then be carried out, for example, by means of a corresponding cold treatment. For example, the switch can be treated manually with the help of a cold spray, which then deactivates the lock and closes the switch again.

In a further embodiment, it is provided that the switch has a housing with a lower part closed by an upper part, the first stationary contact or each of the two stationary contacts being arranged on an inside of the upper part.

This measure is structurally known per se. In the case of the switch, it ensures that when the upper part is mounted on the lower part, the geometrically correct association between the first contact or the first and second contact with the movable contact member is also established at the same time.

According to a further embodiment, it is preferred that the counter holder is arranged in the interior of the housing locally between the temperature-dependent snap part and an inner bottom surface of the lower part. In this embodiment, it is preferred that the anchor element is arranged on the movable contact member.

The counter holder is then arranged in the interior of the housing below the switching mechanism. The counter-holder is preferably fixedly mounted in the housing, particularly preferably it is connected to the housing in a force-fit, form-fit and / or material-fit manner. A particularly simple type of assembly of the counter-holder can be ensured in that it is clamped in the housing, for example between two spacer disks.

According to a further embodiment, it is provided that the switching mechanism has a temperature-independent spring part which is connected to the movable contact member, the temperature-dependent snap part acting on the spring part when the switching temperature is exceeded and thereby lifts the movable contact member from the first contact. It is particularly preferred here that the spring part is a bistable spring part with two temperature-independent, stable geometric configurations.

If the spring part is designed as a bistable spring washer, it is preferred that the spring washer presses the movable contact member against the first contact in its first stable configuration and keeps the movable contact member spaced apart from the first contact in its second stable configuration. This has the advantage that in the closed state of the switch (in the first switching position of the switching mechanism) the spring washer produces the closing force and thus the contact pressure between the movable contact member and the first contact. Thereby the temperature-dependent snap part is mechanically relieved, which has a positive influence on its service life and the long-term stability of its response temperature (switching temperature).

If the spring part is designed as a bistable spring washer with two temperature-independent stable geometric configurations, this has the additional advantage that the bistable spring washer keeps the switch in its open state after opening. Even if the temperature-dependent snap part then wants to snap back into its low-temperature configuration after the switch has cooled down to the reset temperature, the spring washer keeps the switch in its open position in addition to the locking device described above.

The temperature-dependent snap part is preferably designed as a bistable bi- or tri-metal snap disk.

According to a further embodiment, it is preferred that the movable contact member comprises a movable contact part cooperating with the first contact and that the spring part cooperates with the second contact, it is further preferred that the spring part, at least in its first geometric configuration, is electrically connected over its edge is in communication with the second contact.

This configuration is basically from the DE 10 2018 100 890 B3 , the DE 10 2007 042 188 B3 or the DE 10 2013 101 392 A1 known. It means that the temperature-dependent snap part is not subjected to current in any position of the switch, but that the load current of the electrical device to be protected flows through the spring part.

In an alternative embodiment, the movable contact member comprises a current transmission member that interacts with both stationary contacts.

The advantage here is that the switch can carry considerably higher currents than that from the DE 10 2007 042 188 B3 known switches. The current transfer element arranged on the contact element ensures the electrical short circuit between the two contacts when the switch is closed, so that not only the temperature-dependent snap part, but also the temperature-independent spring part are no longer traversed by the load current, as in principle already from the DE 10 2013 101 392 A1 is known.

It goes without saying that the features mentioned above and those yet to be explained below can be used not only in the respectively specified combination, but also in other combinations or on their own, without departing from the scope of the present invention.

Fig. 1

eine schematische Schnittansicht eines ersten Ausführungsbeispiels des erfindungsgemäßen Schalters in seiner Tieftemperaturstellung;

Fig. 2

eine schematische Schnittansicht des in Fig. 1 gezeigten ersten Ausführungsbeispiels des erfindungsgemäßen Schalters in seiner Hochtemperaturstellung;

Fig. 3

eine schematische Schnittansicht eines zweiten Ausführungsbeispiels des erfindungsgemäßen Schalters in seiner Tieftemperaturstellung;

Fig. 4

eine schematische Schnittansicht des in Fig. 3 gezeigten zweiten Ausführungsbeispiels des erfindungsgemäßen Schalters in seiner Hochtemperaturstellung; und

Fig. 5

eine schematische Draufsicht, zur Veranschaulichung des Zusammenwirkens eines Ankerelements mit einem Gegenhalter gemäß einem Ausführungsbeispiel der vorliegenden Erfindung.

Exemplary embodiments of the invention are shown in the drawing and are explained in more detail in the following description. Show it:

Fig. 1

a schematic sectional view of a first embodiment of the switch according to the invention in its low-temperature position;

Fig. 2

a schematic sectional view of the in Fig. 1 shown first embodiment of the switch according to the invention in its high temperature position;

Fig. 3

a schematic sectional view of a second embodiment of the switch according to the invention in its low-temperature position;

Fig. 4

a schematic sectional view of the in Fig. 3 shown second embodiment of the switch according to the invention in its high temperature position; and

Fig. 5

a schematic plan view to illustrate the interaction of an anchor element with a counter holder according to an embodiment of the present invention.

In Fig. 1 is shown in a schematic, sectional side view of a switch 10, which is rotationally symmetrical in plan view and preferably has a circular shape.

The switch 10 has a housing 12 in which a temperature-dependent switching mechanism 14 is arranged. The housing 12 comprises a pot-like lower part 16 and an upper part 18 which is held on the lower part 16 by a bent or flanged edge 20.

In the in Fig. 1 The first embodiment shown is both the lower part 16 and the upper part 18 made of an electrically conductive material, preferably made of metal. Between the lower part 16 and the upper part 18, a spacer ring 22 is arranged, which carries the upper part 18 with an insulating film 24 in between and keeps the upper part 18 at a distance from the lower part 16.

The insulating film 24 ensures electrical insulation of the upper part 18 from the lower part 16. The insulating film 24 also provides a mechanical seal that prevents liquids or contaminants from entering the interior of the housing from the outside.

Since the lower part 16 and the upper part 18 in this exemplary embodiment are each made of electrically conductive material, thermal contact with an electrical device to be protected can be established via their outer surfaces. The outer surfaces also serve for the electrical external connection of the switch 10 at the same time.

On the outside of the upper part 18, as in Fig. 1 shown, a further insulation layer 26 may be attached.

The switching mechanism 14 has a temperature-independent spring part 28 and a temperature-dependent snap part 30. The spring part 28 is preferably designed as a bistable spring washer. Accordingly, it has two geometric configurations that are stable, independent of temperature. In Fig. 1 its first configuration is shown. The temperature-dependent snap part 30 is preferably also designed as a bistable snap disk. This has two temperature-dependent configurations, a geometrical high-temperature configuration and a geometrical low-temperature configuration. In the in Fig. 1 The first switching position of the switching mechanism 14 shown is the temperature-dependent snap disk 30 in its geometric low-temperature configuration.

The temperature-independent spring washer 28 rests with its edge 32 on a circumferential shoulder 34 formed in the lower part 16 and is clamped between this shoulder 34 and the spacer ring 22. The temperature-dependent snap disk 30 is in its low-temperature configuration, as shown in FIG Fig. 1 is shown, with its edge 36 on a further spacer ring 38.

With its center 40, the temperature-independent spring washer 28 is fixed on a movable contact member 42 of the switching mechanism 14. The temperature-dependent snap disk 30 is also fixed with its center 44 on this contact member 42. The movable contact member 42 has a contact part 46 and a ring 45 which is pressed onto the contact part 46. The ring 45 has a circumferential shoulder 47 on which the snap disk 30 rests with its center 44. The spring washer 28 is clamped between the ring 45 and the upper, widened section of the contact part 46. In this way, the temperature-dependent switching mechanism 14 is a captive unit of contact element 42, spring washer 28 and snap disk 30. When the switch 10 is installed, the switching mechanism 14 can be inserted directly into the lower part 16 as a unit.

The contact part 46 of the movable contact member 42 cooperates with a fixed mating contact 48 which is arranged on the inside of the upper part 18. This mating contact 48 is also referred to here as the first stationary contact. The outside of the lower part 16 serves as the second stationary contact 50.

In the in Fig. 1 The position shown is the switch 10 in its low-temperature position, in which the spring washer 28 is in its first configuration and the snap disk 30 is in its low-temperature configuration. The spring washer 28 presses the movable contact member 42 against the first stationary contact 48.

In the closed low-temperature position of the switch 10 according to Fig. 1 an electrically conductive connection is thus established between the first stationary contact 48 and the second stationary contact 50 via the movable contact member 42 and the spring washer 28.

If the temperature of the device to be protected increases, and thus the temperature of the switch 10 and the temperature-dependent snap disk 30 arranged therein, it snaps from the device in FIG Fig. 1 low-temperature configuration shown in its concave high-temperature configuration, which is shown in Fig. 2 is shown. During this snapping over, the snap disk 30 is supported with its edge 36 on a part of the switch 10, in this case on the edge 32 of the spring washer 28. With its center 44, the snap disk 30 pulls the movable contact member 42 downwards and lifts the movable one Contact part 46 from the first stationary contact 48. As a result, it simultaneously bends the spring washer 28 downwards at its center 40, so that the spring washer 28 from its in Fig. 1 shown (first stable geometric configuration) in its in Fig. 2 The second geometrically stable configuration shown snaps over. Fig. 2 thus shows the high temperature position of the switch 10 in which it is open. The circuit is thus interrupted.

When the device to be protected and thus the switch 10 together with the temperature-dependent snap disk 30 then cool down again, the snap disk 30 snaps back into its low-temperature configuration, as shown, for example, in FIG Fig. 1 is shown. Then the snap disk 30 would actually return the spring washer 28 to its first, in Fig. 1 Move the configuration shown back and thus close the switch 10 again. In the switch 10 according to the invention, however, this downshifting process can be prevented by a locking lock 52.

The closing lock 52 has a temperature-dependent anchor element 54 and a counter-holder 56 cooperating with the anchor element 54. An opening 58 is provided in the counter holder 56. In the exemplary embodiment shown here, this opening 58 is designed as a through hole.

The anchor element 54 is arranged on the underside of the movable contact member 42. It may be integrally connected to the movable contact member 42. It is also possible to design the movable contact member 42 and the anchor element 54 as two separate components that are connected to one another in a materially bonded manner, for example by welding, soldering or gluing.

In the present case, the counter holder 56 is designed as a plate-shaped element and essentially has the shape of a circular disk or circular ring disk. The counter holder 56 is clamped between the spacer ring 38 and a further spacer ring 60, which is arranged on the inner bottom surface 62 of the lower part 16. It goes without saying, however, that other types of fastening within the housing 12 for the counter holder 56 are also possible.

The anchor element 54 is designed to change its shape as a function of its temperature. The armature element 54 is set up in particular to change its shape from a first shape to a second shape when a predefined armature switching temperature is exceeded. In the first form, which is shown schematically in Fig. 1 is shown, the anchor element 54 fits through the opening 58 in the counter holder 56. The anchor element 54 is therefore freely movable in this state relative to the counter holder 56. Accordingly, the movable contact member 42 is neither by the anchor element 54 nor by the counter holder 56 on its Switching movement within the housing 12 prevented as long as the anchor element 54 has its first shape. The locking lock 52 has not yet been activated.

However, if the temperature of the armature element 54 exceeds the armature switching temperature, the armature element 54 assumes its second shape in which it no longer fits through the opening 58 in the counter holder 56. The rear derailleur 14 is in his second switch position in which the switch 10, as in Fig. 2 is open, the anchor element 54 can mechanically lock with the counter holder 56. Since the anchor element 54 then no longer fits through the opening 58, the anchor element 54 is prevented by the counter holder 56 from moving into Fig. 2 move back up. Accordingly, the movable contact member 42 can also no longer move towards the first stationary contact 48 in order to come into contact therewith. Regardless of the position of the temperature-dependent snap disk 30 and the temperature-independent spring disk 28, the switch 10 therefore remains open. Closing point 52 prevents the switch 10 from closing again.

The closing lock 52 is preferably activated as follows: As long as the switching mechanism 14 is in its first switching position (closed switch, see FIG Fig. 1 ), the anchor element 54 is at least partially in the opening 58 or on a first side facing the first stationary contact 48 (upper side in Fig. 1 and 2 ) of the counter holder 56. The anchor element 54 should have its first form in which it fits through the opening 58. Otherwise, the armature element 54 could open the switch 10, that is, the switching process from the first, closed switch position (see FIG Fig. 1 ) to the second, open switch position (see Fig. 2 ) undesirably prevent. The armature switching temperature at which the armature element 54 changes its shape from the first shape to the second shape is therefore preferably selected to be at least equal to or higher than the switching temperature of the temperature-dependent snap disk 30. As a result, the armature element 54 only then assumes its second form when the switching mechanism 14 is in its second switching position and not already while the switching mechanism 14 is in its first switching position.

In principle, however, it would also be possible to select the armature switching temperature of the armature element 54 lower than the switching temperature of the temperature-dependent snap disk 30. In this case, however, the armature element 54 must not be arranged above the counter holder 56 as long as the switching mechanism 14 is in its first switching position is located. Instead, the anchor element 54 must then inevitably be arranged in the opening 58 as long as the switching mechanism 14 is in its first switching position. If the anchor element 54 tries to assume its second shape before the switching mechanism 14 is in its second, open switching position is located, the anchor element 54 is prevented from changing its shape by the counter holder 56 as long as it is located within the opening 58.

During the switching process by which the switch 10 is opened, the anchor element 54 is pushed through the opening 58 designed as a through hole. In the second, open switch position of the switch 10, the armature element 54 is thus located on a second side of the counter holder 56 facing away from the first stationary contact 48 (see FIG Fig. 2 ). If the anchor element 54 has its second shape in this position, in which it no longer fits through the opening 58, the movable contact member 42 together with the anchor element 54 remains in its position Fig. 2 shown, lower position. The switch 10 is thus prevented from switching back.

In order to be able to bring about the described temperature-dependent change in shape of the anchor element 54, it preferably has a bimetal part and / or a shape memory alloy. The anchor element 54 can, for example, similar to the temperature-dependent snap disk 30, have a snap disk made of bimetal. This bimetal snap disk of the anchor element 54 can, for example, have the shape of a C in its low-temperature position, as shown in FIG Fig. 5 is shown schematically with reference to the dashed line 64. In this embodiment, the opening 58 in the counter holder 56 has an equivalent shape, which also essentially corresponds to a C. In its low-temperature position, the bimetal snap disk of the anchor element 54 thus fits through the opening 58, as is shown in FIG Fig. 5 shown plan view of the counter holder can be seen.

When the armature switching temperature is exceeded, the bimetal snap disk of the armature element 54 then snaps into the shape of an inverted C, as shown in FIG Fig. 5 is indicated schematically by the dotted line 66. The anchor element 54 can then no longer move through the opening 58.

The use of a bimetal snap disk to achieve the desired change in shape of the anchor element 54 has the advantage, among other things, that this change in shape, similar to the bimetal snap disk 30, can be designed to be reversible. The Armature element 54 can thus also snap back from its second shape 66 into its first shape 64 when an armature reset temperature is reached. This enables a reversible locking lock 52 to be achieved.

For example, the bimetal snap disk 30 of the switching mechanism 14 and the bimetal snap disk of the armature element 54 can be designed such that the armature reset temperature at which the armature snaps out of its second shape 66 back into its first shape 64 is selected to be lower than that Reset temperature of the bimetal snap disk 30. When the temperature of the bimetal snap disk 30 falls below the reset temperature, the bimetal snap disk 30 tries to move out of its in Fig. 2 high temperature configuration shown in their in Fig. 1 to snap back the low temperature configuration shown. However, this is then prevented by the closing lock 52, since this remains activated as before when the switch-back temperature of the bimetal snap disk 30 is not reached. However, by means of a cold treatment intentionally carried out from the outside, the switch 10 can be cooled to a temperature below the armature reset temperature, as a result of which the closing lock 52 is canceled and the switch 10 is closed. In order to avoid unintentional lifting of the closing lock 52, it is therefore preferred that the armature reset temperature is selected as low as possible, for example below 10 ° C.

The described shape change properties of the anchor element 54 can alternatively also be achieved with the aid of a shape memory alloy. With such shape memory alloys, diverse, temperature-dependent changes in shape are possible.

According to one embodiment, the armature element 54 can be designed with a shape memory alloy in such a way that the armature element 54 increases its effective width when the armature switching temperature is reached and instead becomes somewhat thinner.

A reversible type of design of the closing lock 52 can easily be achieved with the aid of an anchor element 54 made of shape memory alloy. In this case, only a shape memory alloy with a two-way memory effect is used, which enables a reversible change in shape of the anchor element 54. At When the armature switching temperature is reached, the shape memory alloy changes its shape from the first shape in which the armature element 54 fits through the opening 58 to the second shape in which the armature element 54 no longer fits through the opening 58. If the armature reset temperature is subsequently undershot, the shape memory alloy ensures that the armature element 54 assumes its first shape again, so that the closing lock 52 is canceled.

By using a shape memory alloy with a one-way memory effect, the anchor element 54 and thus also the closing lock 52 can alternatively also be configured irreversibly. This is particularly advantageous for use in very simple, inexpensive switches, which should remain open permanently after being opened once in order to permanently prevent reclosing of the circuit of the device to be protected for safety reasons.

Fig. 3 and 4th show a further exemplary embodiment of the switch 10 according to the invention. The locking lock 52 is configured here in the same or a similar manner as mentioned above. The mode of operation of the locking lock 52 is therefore not explained again in this regard. Components that are otherwise identical or similar to those above are not explained again either. The in Fig. 3 and 4th The switch 10 shown differs from that in FIG Fig. 1 and 2 However, the switch shown is basically due to the structure of the housing 12 'and the switching mechanism 14'. These differences are briefly explained below.

The lower part 16 'is again made of electrically conductive material. On the other hand, the flat upper part 18 ′ is here made of electrically insulating material. It is held on the lower part 16 'by a bent-over edge 68.

Here, too, a spacer ring 22 'is provided between the upper part 18' and the lower part 16 ', which keeps the upper part 18' at a distance from the lower part 16 '. On its inside, the lower part 18 'has a first stationary contact 48' and a second stationary contact 50 '. The contacts 48 'and 50' are designed as rivets, which extend through the upper part 18 ′ and end on the outside in the heads 70, 72, which are used for the external connection of the switch 10.

The movable contact member 42 'here comprises a current transmission member 74, which in the in Fig. 3 and 4th The embodiment shown is a contact plate, the upper side of which is coated in an electrically conductive manner, so that in Fig. 3 shown, closed position of the switch 10 is applied to the contacts 48 ', 50' and ensures an electrically conductive connection between the contacts 48 'and 50'. The current transmission member 74 is connected to the spring washer 28 and the snap washer 30 via a rivet 76, which is also to be regarded as part of the contact member 42 ′. If the switching temperature is exceeded, the bimetal snap disk 30 of the switching mechanism 14 'ensures, similarly as before, that the switching mechanism 14' is brought into its second switching position in which the current transmission element 74 is kept at a distance from the two contacts 48 ', 50' and the circuit is therefore interrupted. This second switch position is in Fig. 4 shown.

The main advantage of the in Fig. 3 and 4th The circuit structure shown in the figure can be seen in the fact that, in contrast to the Fig. 1 and 2 Embodiment of the switch 10 shown here neither through the spring washer 28 nor through the snap disk 30 in the closed state of the switch 10, a current flows. In the closed state of the switch 10, this only flows from the first external connection 70 via the first stationary contact 48 ′, the current transmission element 74 and the second stationary contact 50 ′ to the second external connection 72.

Finally, it should be mentioned that both in Fig. 1 and 2 switch structure shown as well as the in Fig. 3 and 4th The switch structure shown, the locking mechanism 52 can also be designed kinematically reversed. The counterholder 56 can be arranged on the movable contact member 42 or 42 'or another component of the switching mechanism 14 or 14', so that the counterholder 56 then moves along with the switching mechanism 14, 14 '. The anchor element 54 is then attached to the housing 12, 12 'in this case. For example, the anchor element can be mounted on the inner bottom surface 62 of the lower part 16, 16 'so that it is then in the second switching position of the switching mechanism 14, 14 'protrudes from below through the opening 58 in the counter holder 56 and when the locking device 52 is activated, the counter holder 56 hooks in from its upper side.

It is also understood that the opening 58 in the counter holder 56 does not necessarily have to be designed as a through opening. The opening 58 can also be designed as a type of rear grip, cavity or blind hole in the counter holder 56. It is only important that the anchor element 54 can hook onto the counter holder 56 as soon as the anchor element 54 assumes its second shape. This is independent of whether the anchor element 54 or the counter holder 56 is arranged on the switching mechanism 14, 14 'and moves with it.

1. (1) Temperaturabhängiger Schalter 10, der einen ersten und einen zweiten stationären Kontakt 48, 50 sowie ein temperaturabhängiges Schaltwerk 14 mit einem beweglichen Kontaktglied 42 aufweist, wobei das Schaltwerk 14 in seiner ersten Schaltstellung das Kontaktglied 42 gegen den ersten Kontakt 48 drückt und dabei über das Kontaktglied 42 eine elektrisch leitende Verbindung zwischen den beiden Kontakten 48, 50 herstellt und in seiner zweiten Schaltstellung das Kontaktglied 42 zu dem ersten Kontakt 48 beabstandet hält und damit die elektrisch leitende Verbindung zwischen den beiden Kontakten 48, 50 unterbricht, wobei das temperaturabhängige Schaltwerk 14 ein temperaturabhängiges Schnappteil 30 aufweist, das bei Überschreiten einer Schalttemperatur aus seiner geometrischen Tieftemperaturkonfiguration in seine geometrische Hochtemperaturkonfiguration umschnappt und bei einem anschließenden Unterschreiten einer Rückschalttemperatur wieder aus seiner geometrischen Hochtemperaturkonfiguration zurück in seine geometrische Tieftemperaturkonfiguration umschnappt, wobei ein Umschnappen des temperaturabhängigen Schnappteils 30 aus seiner geometrischen Tieftemperaturkonfiguration in seine geometrische Hochtemperaturkonfiguration das Schaltwerk 14 aus seiner ersten Schaltstellung in seine zweite Schaltstellung bringt und damit den Schalter 10 öffnet, und wobei eine Schließsperre 52 vorgesehen ist, die ein erneutes Schließen des geöffneten Schalters 10 verhindert, in dem sie das Schaltwerk 14 in dessen zweiter Schaltstellung hält, sobald sie aktiviert ist, wobei die Schließsperre 52 ein temperaturabhängiges Ankerelement 54 und einen mit dem Ankerelement 54 zusammenwirkenden Gegenhalter 56 mit einer Öffnung 58 aufweist, wobei das Ankerelement 54 dazu eingerichtet ist, seine Form bei Überschreiten einer Anker-Schalttemperatur von einer ersten Form, in der das Ankerelement durch die Öffnung 58 passt, so dass die Schließsperre 52 nicht aktiviert ist, in eine zweite Form, in der das Ankerelement 54 nicht mehr durch die Öffnung 58 passt, so dass die Schließsperre 52 aktiviert ist, zu verändern.
2. (2) Schalter nach Ausführungsbeispiel 1, wobei das Ankerelement 54 dazu eingerichtet ist, seine Form bei Unterschreiten einer Anker-Rückschalttemperatur von der zweiten Form in die erste Form zu verändern, wobei die Anker-Rückschalttemperatur niedriger als die Anker-Schalttemperatur ist.
3. (3) Schalter nach Ausführungsbeispiel 1 oder 2, wobei das Ankerelement 54 ein Bimetallteil aufweist.
4. (4) Schalter nach einem der Ausführungsbeispiele 1 bis 3, wobei das Ankerelement 54 ein Bauteil aus einer Formgedächtnislegierung aufweist.
5. (5) Schalter nach Ausführungsbeispiel 4, wobei die Formgedächtnislegierung eine Formgedächtnislegierung mit Einweg-Memory-Effekt ist.
6. (6) Schalter nach Ausführungsbeispiel 4, wobei die Formgedächtnislegierung eine Formgedächtnislegierung mit Zweiweg-Memory-Effekt ist.
7. (7) Schalter nach einem der Ausführungsbeispiele 1 bis 6, wobei das Ankerelement 54 dazu eingerichtet ist, das Schaltwerk 14 in seiner zweiten Schaltstellung mechanisch zu arretieren, wenn das Ankerelement 54 seine zweite Form aufweist.
8. (8) Schalter nach einem der Ausführungsbeispiele 1 bis 7, wobei der Schalter 10 ferner ein Gehäuse 12 aufweist, und dass entweder i das Ankerelement 54 an einem Teil des Schaltwerks 14 angeordnet oder befestigt ist und der Gegenhalter 56 an dem Gehäuse 12 angeordnet oder befestigt ist oder ii der Gegenhalter 56 an dem Teil des Schaltwerks 14 angeordnet oder befestigt ist und das Ankerelement 54 an dem Gehäuse 12 angeordnet oder befestigt ist.
9. (9) Schalter nach Ausführungsbeispiel 8, wobei der besagte Teil des Schaltwerks 14 das bewegliche Kontaktglied 42 ist.
10. (10) Schalter nach einem der Ausführungsbeispiele 1 bis 9, wobei das Ankerelement 54 in der ersten Schaltstellung des Schaltwerks 14 zumindest teilweise in der Öffnung 58 oder auf einer ersten Seite des Gegenhalters 56 angeordnet ist, und wobei das Ankerelement 54 in der zweiten Schaltstellung des Schaltwerks 14 durch die Öffnung 58 hindurch gesteckt ist und auf einer der ersten Seite gegenüberliegenden zweiten Seite des Gegenhalters 56 angeordnet ist.
11. (11) Schalter nach einem der Ausführungsbeispiele 1 bis 10, wobei der Gegenhalter 56 ein im Wesentlichen plattenförmiges Element mit einem Loch, das die Öffnung 58 bildet, aufweist.
12. (12) Schalter nach einem der Ausführungsbeispiele 1 bis 10, wobei die Anker-Schalttemperatur gleich hoch oder höher ist als die Schalttemperatur des temperaturabhängigen Schnappteils 30.
13. (13) Schalter nach Ausführungsbeispiel 2, wobei die Anker-Rückschalttemperatur niedriger ist als die Rückschalttemperatur des temperaturabhängigen Schnappteils 30.
14. (14) Schalter nach einem der Ausführungsbeispiele 1 bis 13, wobei der Schalter 10 ein Gehäuse 12 mit einem von einem Oberteil 18 verschlossenen Unterteil 16 aufweist, wobei an einer Innenseite des Oberteils 18 der erste stationäre Kontakt 48 oder jeder der beiden stationären Kontakte 48, 50 angeordnet ist.
15. (15) Schalter nach einem der Ausführungsbeispiele 1 bis 14, wobei der Gegenhalter 56 im Inneren des Gehäuses 12 örtlich zwischen dem temperaturabhängigen Schnappteil 30 und einer Innenbodenfläche 62 des Unterteils 16 angeordnet ist.
16. (16) Schalter nach einem der Ausführungsbeispiele 1 bis 15, wobei das Schaltwerk 14 ein temperaturunabhängiges Federteil 28 aufweist, das mit dem beweglichen Kontaktglied 42 verbunden ist, wobei das temperaturabhängige Schnappteil 30 bei Überschreiten der Schalttemperatur auf das Federteil 28 einwirkt und dadurch das bewegliche Kontaktglied 42 von dem ersten Kontakt 48 abhebt.
17. (17) Schalter nach Ausführungsbeispiel 16, wobei das Federteil 28 ein bistabiles Federteil mit zwei temperaturunabhängigen, stabilen geometrischen Konfigurationen ist.
18. (18) Schalter nach einem der Ausführungsbeispiele 1 bis 17, wobei das temperaturabhängige Schnappteil 30 eine Bi- oder Trimetall-Schnappscheibe ist.
19. (19) Schalter nach Ausführungsbeispiel 16 oder 17, wobei das bewegliche Kontaktglied 42 ein mit dem ersten Kontakt 48 zusammenwirkendes bewegliches Kontaktteil 46 umfasst, und dass das Federteil 28 mit dem zweiten Kontakt 50 zusammenwirkt.
20. (20) Schalter nach einem der Ausführungsbeispiele 1 bis 19, wobei das bewegliche Kontaktglied 42' ein mit beiden stationären Kontakten 48', 50' zusammenwirkendes Stromübertragungsglied 74 umfasst.

The following is a list of further exemplary embodiments:

1. (1) Temperature-dependent switch 10, which has a first and a second stationary contact 48, 50 and a temperature-dependent switching mechanism 14 with a movable contact element 42, the switching mechanism 14 in its first switching position pressing the contact element 42 against the first contact 48 and thereby over the contact member 42 establishes an electrically conductive connection between the two contacts 48, 50 and, in its second switching position, keeps the contact member 42 spaced from the first contact 48 and thus interrupts the electrically conductive connection between the two contacts 48, 50, the temperature-dependent switching mechanism 14 has a temperature-dependent snap part 30 which, when a switching temperature is exceeded, snaps from its geometric low-temperature configuration to its geometric high-temperature configuration and, when the temperature subsequently falls below a switch-back temperature, again from its geometric high-temperature configuration snaps back into its geometric low-temperature configuration, with a snap-over of the temperature-dependent snap part 30 from its geometric low-temperature configuration into its geometric high-temperature configuration brings the switching mechanism 14 from its first switch position into its second switch position and thus opens the switch 10, and a locking lock 52 is provided which prevents the open switch 10 from closing again by holding the switching mechanism 14 in its second switch position as soon as it is activated, The closing lock 52 has a temperature-dependent armature element 54 and a counter-holder 56 with an opening 58 that interacts with the armature element 54, the armature element 54 being designed to change its shape when an armature switching temperature is exceeded from a first shape, in which the armature element passes through the Opening 58 fits, so that the closing lock 52 is not activated, to change into a second shape in which the anchor element 54 no longer fits through the opening 58, so that the closing lock 52 is activated.
2. (2) Switch according to embodiment 1, the armature element 54 being configured to change its shape from the second shape to the first shape when the armature reset temperature is undershot, the armature reset temperature being lower than the armature switching temperature.
3. (3) Switch according to embodiment 1 or 2, wherein the armature element 54 has a bimetallic part.
4. (4) Switch according to one of the exemplary embodiments 1 to 3, the armature element 54 having a component made from a shape memory alloy.
5. (5) Switch according to embodiment 4, wherein the shape memory alloy is a shape memory alloy with a one-way memory effect.
6. (6) Switch according to embodiment 4, wherein the shape memory alloy is a shape memory alloy with a two-way memory effect.
7. (7) Switch according to one of the exemplary embodiments 1 to 6, the armature element 54 being set up to mechanically lock the switching mechanism 14 in its second switching position when the armature element 54 has its second shape.
8. (8) Switch according to one of the exemplary embodiments 1 to 7, wherein the switch 10 furthermore has a housing 12, and that either the armature element 54 is arranged or fastened to a part of the switching mechanism 14 and the counter holder 56 is arranged or fastened on the housing 12 or ii the counter holder 56 is arranged or fastened on the part of the switching mechanism 14 and the anchor element 54 is arranged or fastened on the housing 12.
9. (9) Switch according to embodiment 8, said part of the switching mechanism 14 being the movable contact member 42.
10. (10) Switch according to one of the exemplary embodiments 1 to 9, wherein the armature element 54 in the first switching position of the switching mechanism 14 is at least partially arranged in the opening 58 or on a first side of the counter holder 56, and wherein the armature element 54 is in the second switching position of the Switching mechanism 14 is inserted through the opening 58 and is arranged on a second side of the counter holder 56 opposite the first side.
11. (11) Switch according to one of the exemplary embodiments 1 to 10, the counter holder 56 having an essentially plate-shaped element with a hole which forms the opening 58.
12. (12) Switch according to one of the exemplary embodiments 1 to 10, the armature switching temperature being equal to or higher than the switching temperature of the temperature-dependent snap part 30.
13. (13) Switch according to embodiment 2, the armature reset temperature being lower than the reset temperature of the temperature-dependent snap part 30.
14. (14) Switch according to one of the exemplary embodiments 1 to 13, the switch 10 having a housing 12 with a lower part 16 closed by an upper part 18, the first stationary contact 48 or each of the two stationary contacts 48, on an inner side of the upper part 18, 50 is arranged.
15. (15) Switch according to one of the exemplary embodiments 1 to 14, the counter holder 56 being arranged in the interior of the housing 12 locally between the temperature-dependent snap part 30 and an inner bottom surface 62 of the lower part 16.
16. (16) Switch according to one of the exemplary embodiments 1 to 15, the switching mechanism 14 having a temperature-independent spring part 28 which is connected to the movable contact member 42, the temperature-dependent snap part 30 acting on the spring part 28 when the switching temperature is exceeded and thereby the movable contact member 42 stands out from the first contact 48.
17. (17) Switch according to embodiment 16, wherein the spring part 28 is a bistable spring part with two temperature-independent, stable geometric configurations.
18. (18) Switch according to one of the exemplary embodiments 1 to 17, wherein the temperature-dependent snap part 30 is a bi- or tri-metal snap disk.
19. (19) Switch according to embodiment 16 or 17, wherein the movable contact member 42 comprises a movable contact part 46 cooperating with the first contact 48, and in that the spring part 28 cooperates with the second contact 50.
20. (20) Switch according to one of the exemplary embodiments 1 to 19, wherein the movable contact element 42 ′ comprises a current transmission element 74 which cooperates with the two stationary contacts 48 ′, 50 ′.

Claims (15)

Temperature-dependent switch (10) which has a first and a second stationary contact (48, 50) and a temperature-dependent switching mechanism (14) with a movable contact element (42), the switching mechanism (14) in its first switching position the contact element (42) presses against the first contact (48) and thereby establishes an electrically conductive connection between the two contacts (48, 50) via the contact member (42) and, in its second switching position, keeps the contact member (42) spaced from the first contact (48) and so that the electrically conductive connection between the two contacts (48, 50) is interrupted, the temperature-dependent switching mechanism (14) having a temperature-dependent snap-in part (30) which, when a switching temperature is exceeded, snaps from its geometric low-temperature configuration to its geometric high-temperature configuration and when it is subsequently undershot a reset temperature again from its geometric high temperature configuration snaps back into its geometrical low-temperature configuration, with a snapping of the temperature-dependent snap part (30) from its geometrical low-temperature configuration into its geometrical high-temperature configuration brings the switching mechanism (14) from its first switch position into its second switch position and thus opens the switch (10), and with a closing lock (52) is provided which prevents the open switch (10) from closing again by holding the switching mechanism (14) in its second switching position as soon as it is activated,
characterized in that the closing lock (52) has a temperature-dependent anchor element (54) and a counter-holder (56) which cooperates with the anchor element (54) and has an opening (58), the anchor element (54) being designed to change its shape when it is exceeded an armature switching temperature from a first form, in which the armature element fits through the opening (58), so that the closing lock (52) is not activated, to a second form, in which the armature element (54) no longer passes through the opening ( 58) fits so that the locking device (52) is activated. Switch according to Claim 1, characterized in that the armature element (54) is designed to change its shape from the second shape to the first shape when the armature reset temperature is undershot, the armature reset temperature being lower than the armature switching temperature. Switch according to Claim 1 or 2, characterized in that the armature element (54) has a bimetal part. Switch according to one of Claims 1 to 3, characterized in that the armature element (54) has a component made from a shape memory alloy. Switch according to Claim 4, characterized in that the shape memory alloy is a shape memory alloy with a one-way memory effect. Switch according to Claim 4, characterized in that the shape memory alloy is a shape memory alloy with a two-way memory effect. Switch according to one of Claims 1 to 6, characterized in that the armature element (54) is set up to mechanically lock the switching mechanism (14) in its second switching position when the armature element (54) has its second shape. Switch according to one of Claims 1 to 7, characterized in that the switch (10) furthermore has a housing (12), and that either (i) the armature element (54) is arranged or fastened to a part of the switching mechanism (14) and the counter holder (56) is arranged or fastened to the housing (12) or (ii) the counter holder (56) is arranged or fastened to the part of the switching mechanism (14) and the anchor element (54) is arranged on the housing (12) or is attached. Switch according to claim 8, characterized in that said part of the switching mechanism (14) is the movable contact member (42). Switch according to one of claims 1 to 9, characterized in that the armature element (54) in the first switching position of the switching mechanism (14) is arranged at least partially in the opening (58) or on a first side of the counter holder (56), and wherein the anchor element (54) is inserted through the opening (58) in the second switching position of the switching mechanism (14) and is arranged on a second side of the counter-holder (56) opposite the first side. Switch according to one of Claims 1 to 10, characterized in that the counter holder (56) has an essentially plate-shaped element with a hole which forms the opening (58). Switch according to one of Claims 1 to 10, characterized in that the armature switching temperature is equal to or higher than the switching temperature of the temperature-dependent snap part (30), and / or that the armature reset temperature is lower than the reset temperature of the temperature-dependent snap part (30) ). Switch according to one of claims 1 to 12, characterized in that the switch (10) has a housing (12) with a lower part (16) closed by an upper part (18), the first stationary on an inside of the upper part (18) Contact (48) or each of the two stationary contacts (48, 50) is arranged. Switch according to Claim 13, characterized in that the counter holder (56) is arranged in the interior of the housing (12) locally between the temperature-dependent snap part (30) and an inner bottom surface (62) of the lower part (16). Switch according to one of claims 1 to 14, characterized in that the switching mechanism (14) has a temperature-independent spring part (28) which is connected to the movable contact member (42), the temperature-dependent Snap part (30) acts on the spring part (28) when the switching temperature is exceeded and thereby lifts the movable contact member (42) off the first contact (48).

Images