EP4310878B1 - Temperature-dependent switching device, temperature-dependent switch, and method for producing a temperature-dependent switching device - Google Patents

Description

The present invention relates to a temperature-dependent switching mechanism for a temperature-dependent switch. The present invention further relates to a temperature-dependent switch with such a temperature-dependent switching mechanism. Furthermore, the present invention relates to a method for producing a temperature-dependent switching mechanism that can be used in a temperature-dependent switch.

Temperature-dependent switches are already known in many different forms. An example of a temperature-dependent switch is shown in the DE 10 2011 119 632 B3 revealed.

Such temperature-dependent switches are used in a known manner to monitor the temperature of a device. To do this, the switch is brought into thermal contact with the device to be protected, for example via one of its outer surfaces, so that the temperature of the device to be protected influences the temperature of the switching mechanism arranged inside the switch.

The switch is typically connected electrically in series via connecting cables into the supply circuit of the device to be protected, so that below the response temperature of the switch, the supply current of the device to be protected flows through the switch.

In the DE 10 2011 119 632 B3 In the known switch, the switching mechanism is arranged inside a switch housing. The switch housing is constructed in two parts. It has a lower part that is firmly connected to a cover part with an insulating film in between. The temperature-dependent switching mechanism arranged in the switch housing has a spring snap disk to which a movable contact part is attached, as well as a bimetal snap disk that is placed over the movable contact part. The spring snap disk presses the movable contact part against a stationary counter-contact that is arranged on the inside of the switch housing on the cover part. The spring snap disk rests on the outer edge of the spring snap disk. in the lower part of the switch housing, so that the electrical current flows from the lower part through the spring snap disc and the movable contact part into the stationary counter contact and from there into the cover part.

The temperature-dependent bimetal snap disc is essentially responsible for the temperature-dependent switching behavior of the switch. This is usually designed as a multi-layer, active, sheet-metal component made of two, three or four interconnected components with different thermal expansion coefficients. The connection of the individual layers of metals or metal alloys in such bimetal snap discs is usually materially bonded or positively bonded and is achieved, for example, by rolling.

Such a bimetal snap disc has a first stable geometric configuration (low temperature configuration) at low temperatures, below the response temperature of the bimetal snap disc, and a second stable geometric configuration (high temperature configuration) at high temperatures, above the response temperature of the bimetal snap disc. Depending on the temperature, the bimetal snap disc jumps from its low temperature configuration to its high temperature configuration in a hysteresis manner. If the temperature of the bimetal snap disc increases as a result of a temperature increase in the device to be protected above the response temperature of the bimetal snap disc, it snaps from its low temperature configuration to its high temperature configuration. The bimetal snap disc works against the spring snap disc in such a way that it lifts the movable contact part off the stationary counter contact, so that the switch opens and the device to be protected is switched off and cannot heat up any further.

If no switch-back lock is provided, the bimetal snap-action disc snaps back into its low-temperature configuration so that the switch is closed again as soon as the temperature of the bimetal snap-action disc drops below the so-called return temperature of the bimetal snap-action disc as a result of the cooling of the device to be protected.

In its low-temperature configuration, the bimetal snap-action disk is preferably mounted in the switch housing without mechanical forces, whereby the bimetal snap-action disk is also not used to conduct the current. This has the advantage that the bimetal snap-action disk has a longer service life and that the switching point, i.e. the response temperature of the bimetal snap-action disk, does not change even after many switching cycles.

For a large number of temperature-dependent switches, the bimetal snap disc is therefore preferably inserted into the switch housing as a loose individual part during manufacture of the switch, with the bimetal snap disc being slipped over the contact part attached to the spring snap disc, for example with a central through hole provided in it. Only when the switch housing is closed is the bimetal snap disc then fixed in its position and its position relative to the other components of the switching mechanism determined. However, the production of such a switch in which the bimetal snap disc is inserted individually has proven to be relatively complicated, since several steps are necessary to insert the switching mechanism into the switch housing.

In the DE 10 2011 119 632 B3 In the known switch, the bimetal snap disc is therefore connected in advance (outside the switch housing) to the contact part attached to the spring snap disc. To do this, the bimetal snap disc is put over the contact part and then an upper collar of the contact part is folded over. As a result, not only is the spring snap disc attached to the contact part, but the bimetal snap disc is also held captive to it.

The switching mechanism, which consists of the bimetal snap disc, the spring snap disc and the contact part, can be manufactured in advance as a semi-finished product, which forms a captive unit and can be stored separately as bulk goods. When manufacturing the switch, the switching mechanism can then be inserted into the switch housing as a captive unit in just one step. This simplifies the production of the switch many times over.

The spring snap disk is on the one from the DE 10 2011 119 632 B3 Known switches are welded or soldered to the contact part in order to create the best possible electrical contact between the two components. However, it has been shown that, particularly when storing the switchgear pre-produced as a semi-finished product in bulk, the welding or soldering device between the contact part and the spring snap disk can break. Switchgears that are defective in this way can then of course no longer be used.

Also in the DE 199 19 648 A1 A temperature-dependent switch is proposed whose switching mechanism can be produced in advance as a semi-finished product. In this switching mechanism too, the bimetal snap disk, the spring snap disk and the contact part form a captive unit before installation in the switch housing, which can be inserted into the switch housing as a whole during production of the switch and can be stored in advance as bulk goods. In this switching mechanism, the contact part has a jacket made of softer metal and a core made of electrically conductive, harder metal. The bimetal snap disk and the spring snap disk are plugged onto the jacket and molded into the softer metal of the jacket. However, it has been found that this type of connection often leads to the bimetal snap disk and/or the spring snap disk becoming accidentally detached from the contact part during storage of the switching mechanism.

Another possibility of pre-production of the rear derailleur as a semi-finished product is from the DE 29 17 482 A1 and the DE 10 2007 014 237 A1 The captive unit of the switching mechanism is achieved by connecting the bimetal snap disk and the spring snap disk with a rivet. Depending on the design of the switch, this rivet can also form the movable contact part of the switching mechanism. The rivet is constructed in two parts and has a rivet bolt that works together with a hollow rivet or a rivet bolt with a counterholder attached to it.

While this type of rivet connection between spring snap disk and bimetal snap disk has proven to be a mechanically long-lasting connection, the rivet connection does lead to other disadvantages. For example, it usually results in a fixed clamping of the bimetal snap disc to the rivet, which can lead to deformation and thus to malfunctions of the bimetal snap disc.

DE 10 2013 017232 A1 discloses a temperature-dependent switching mechanism according to the preamble of claim 1.

It is therefore an object of the present invention to provide a temperature-dependent switching mechanism that can be produced simply and inexpensively from as few components as possible as a semi-finished product and can be kept in stock as bulk goods without being susceptible to damage that could lead to a defect in the switching mechanism. Furthermore, the present invention is based on the object of providing a method for producing such a temperature-dependent switching mechanism.

• einer temperaturabhängigen Bimetall-Schnappscheibe, die ein erstes Durchgangsloch aufweist;
• einer temperaturunabhängigen Feder-Schnappscheibe, die ein zweite Durchgangsloch aufweist; und
• einem elektrisch leitfähigen Kontaktteil, das einen Grundkörper aufweist, der durch das erste Durchgangsloch und das zweite Durchgangsloch hindurchgeführt ist; wobei das Kontaktteil eine radial von dem Grundkörper abstehende Auflageschulter, ein radial von dem Grundkörper abstehendes erstes Arretierelement, das auf einer ersten Seite der Auflageschulter angeordnet ist, und ein radial von dem Grundkörper abstehendes zweites Arretierelement, das auf einer der ersten Seite gegenüberliegenden zweiten Seite der Auflageschulter angeordnet ist, aufweist, wobei die temperaturabhängige Bimetall-Schnappscheibe zwischen dem ersten Arretierelement und der Auflageschulter angeordnet ist und von dem ersten Arretierelement und der Auflageschulter unverlierbar, aber mit Spiel an dem Grundkörper des Kontaktteils gehalten ist,

• wobei die temperaturunabhängige Feder-Schnappscheibe zwischen dem zweiten Arretierelement und der Auflageschulter angeordnet ist und von dem zweiten Arre-
• tierelement und der Auflageschulter unverlierbar, aber mit Spiel an dem Grundkörper des Kontaktteils gehalten ist, und
• wobei das Kontaktteil einteilig ausgebildet ist und der Grundkörper integral mit der Auflageschulter, dem ersten Arretierelement und dem zweiten Arretierelement verbunden ist.

This object is achieved according to the invention by a temperature-dependent switching mechanism according to claim 1, with:

• a temperature-dependent bimetallic snap disk having a first through hole;
• a temperature-independent spring snap-action disk having a second through hole; and
• an electrically conductive contact part which has a base body which is guided through the first through hole and the second through hole; wherein the contact part has a support shoulder which protrudes radially from the base body, a first locking element which protrudes radially from the base body and is arranged on a first side of the support shoulder, and a second locking element which protrudes radially from the base body and is arranged on a second side of the support shoulder opposite the first side, wherein the temperature-dependent bimetal snap disk is arranged between the first locking element and the support shoulder and is held captive by the first locking element and the support shoulder, but with play, on the base body of the contact part,

• wherein the temperature-independent spring snap disk is arranged between the second locking element and the support shoulder and is supported by the second locking element.
• animal element and the support shoulder are held captive, but with play on the base body of the contact part, and
• wherein the contact part is formed in one piece and the base body is integrally connected to the support shoulder, the first locking element and the second locking element.

• Bereitstellen einer temperaturabhängigen Bimetall-Schnappscheibe, die ein erstes Durchgangsloch aufweist;
• Bereitstellen einer temperaturunabhängigen Feder-Schnappscheibe, die ein zweite Durchgangsloch aufweist;
• Bereitstellen eines elektrisch leitfähigen Kontaktteils, das einen Grundkörper und eine radial von dem Grundkörper abstehende Auflageschulter aufweist;
• Hindurchführen des Grundkörpers durch das erste Durchgangsloch, so dass die Bimetall-Schnappscheibe auf einer ersten Seite der Auflageschulter angeordnet ist;
• Hindurchführen des Grundkörpers durch das zweite Durchgangsloch, so dass die Feder-Schnappscheibe auf einer der ersten Seite gegenüberliegenden zweiten Seite der Auflageschulter angeordnet ist;
• Umformen eines ersten Teils des Grundkörpers, der auf der ersten Seite der Auflageschulter angeordnet ist, um ein erstes Arretierelement derart zu erzeugen, dass die temperaturabhängige Bimetall-Schnappscheibe zwischen dem ersten Arretierelement und der Auflageschulter angeordnet ist und von dem ersten Arretierelement und der Auflageschulter unverlierbar, aber mit Spiel an dem Grundkörper des Kontaktteils gehalten wird; und
• Umformen eines zweiten Teils des Grundkörpers, der auf der zweiten Seite der Auflageschulter angeordnet ist, um ein zweites Arretierelement derart zu erzeugen, dass die temperaturunabhängige Feder-Schnappscheibe zwischen dem zweiten Arretierelement und der Auflageschulter angeordnet ist und von dem zweiten Arretierelement und der Auflageschulter unverlierbar, aber mit Spiel an dem Grundkörper des Kontaktteils gehalten wird.

Furthermore, the above-mentioned object is achieved according to claim 14 by a method for producing a temperature-dependent switching mechanism, which comprises the following steps:

• Providing a temperature-dependent bimetallic snap disk having a first through-hole;
• Providing a temperature independent spring snap disk having a second through hole;
• Providing an electrically conductive contact part having a base body and a support shoulder projecting radially from the base body;
• Passing the base body through the first through hole so that the bimetallic snap disk is arranged on a first side of the support shoulder;
• Passing the base body through the second through hole so that the spring snap disk is arranged on a second side of the support shoulder opposite the first side;
• Forming a first part of the base body, which is arranged on the first side of the support shoulder, in order to produce a first locking element such that the temperature-dependent bimetallic snap disk is arranged between the first locking element and the support shoulder and is held captive by the first locking element and the support shoulder, but with play, on the base body of the contact part; and
• Forming a second part of the base body, which is arranged on the second side of the support shoulder, to produce a second locking element such that that the temperature-independent spring snap disk is arranged between the second locking element and the support shoulder and is held captive by the second locking element and the support shoulder, but with play, on the base body of the contact part.

The switching mechanism according to the invention has an electrically conductive contact part that is guided through through holes in the bimetal snap disk and the spring snap disk. The contact part therefore protrudes through both snap disks. It has a radially protruding support shoulder against which the two snap disks rest from opposite sides. Locking elements that are arranged on both sides of this support shoulder hold the respective snap disk between the support shoulder and the respective locking element captive, but with play on the contact part. The contact part thus forms a captive unit together with the bimetal snap disk and the spring snap disk, which can be pre-produced as a semi-finished product and kept in stock as bulk goods and can then be inserted as a whole into a corresponding switch housing when the switch is assembled.

The locking elements for holding and locking the bimetal snap disc and the spring snap disc are integrally connected to the base body of the contact part. The locking elements are created by forming a respective part of the base body. The contact part is thus formed in one piece and the base body of the contact part is integrally connected to the support shoulder and the two locking elements.

Overall, a switching mechanism consisting of just three parts can be formed from the contact part, the bimetal snap disc and the spring snap disc, which is implemented as a captive unit. This three-part structure has the advantage of requiring as few necessary components as possible, as well as the advantage of a mechanically very stable and robust structure of the switching mechanism.

Unlike the one from the DE 10 2011 119 632 B3 With known switches, the welded or soldered connection between the spring snap disc and the contact part cannot be destroyed, since such a connection does not exist.

Even an unintentional release of the bimetal snap-action disc and/or the spring snap-action disc from the contact part, as is the case with the DE 199 19 648 A1 described is hardly possible due to the locking elements.

The one-piece construction of the contact part is advantageous both for mechanical reasons and in terms of its lower manufacturing costs compared to the two-piece riveted connections used in the DE 10 2007 014 237 A1 and the DE 29 17 482 A1 known switches. In addition, the bimetal snap disk and the spring snap disk are held with play on the base body of the contact part by means of the locking elements, so that undesirable tensions and resulting deformations of the two snap disks can hardly occur.

The above task is thus completely solved.

According to one embodiment, the first locking element has at least one first holding claw that protrudes radially from the base body and is integrally formed therewith, or a first flanged collar that protrudes radially from the base body and runs around the circumference of the base body. Likewise, the second locking element according to this embodiment has at least one second holding claw that protrudes radially from the base body and is integrally formed therewith, or a second flanged collar that protrudes radially from the base body and runs around the circumference of the base body.

One or more retaining claws can be provided for each locking element (first and second locking element). The retaining claws can form individual peripheral sections of the base body or run around the entire circumference of the base body. These retaining claws can be designed as bent or flanged retaining claws.

Instead of holding claws, a circumferential collar can also function as a locking element. This collar can be produced by flanging a part that has been pre-formed accordingly on the base body of the contact part. Alternatively, the collar can also be produced by a circumferential cutting notch made in the base body, through which the material of the base body that is located further out radially is bent radially outwards and forms the collar.

In this way, the two snap disks are held captive to the base body, but with some play. The manufacture of these locking elements is extremely simple. Because they are integrally connected to the base body, the locking elements are designed in a mechanically very stable manner.

According to a further embodiment, a first distance between an upper side of the contact part arranged on the first side of the support shoulder and an underside of the contact part arranged on the second side of the support shoulder is greater than a second distance between the first locking element and the second locking element.

In other words, the locking elements are arranged in an area between the free top and the free bottom of the contact part. Accordingly, the contact part can rest with its free top and its free bottom on corresponding counter contacts or counter contact surfaces without the locking elements coming into contact with the counter contacts or the counter contact surfaces. On the one hand, this creates a precisely defined contact between the contact part and the counter contacts or the counter contact surfaces and, on the other hand, prevents damage to the locking elements.

According to a further embodiment, the bimetal snap disk is held on the base body with greater play than the spring snap disk.

The spring snap disc is therefore preferably clamped more tightly between the support shoulder and the second locking element than the bimetal snap disc is between the support shoulder and the first locking element. The bimetal snap disc This means that it has greater mobility relative to the contact part than the spring snap disc. This guarantees the best possible electrical contact between the spring snap disc and the contact part and also allows sufficient mobility of the bimetal snap disc, which is advantageous in terms of its service life.

Since the bimetal snap disc, unlike the spring snap disc, is preferably not used as a current-carrying component of the switching mechanism, there does not have to be an overly tight clamping between the bimetal snap disc and the contact part.

According to a further embodiment, the switching mechanism is designed to be rotationally symmetrical about a longitudinal axis of the contact part.

This makes it very easy to install the switch mechanism in a switch housing. This also allows for an optimal force effect from the two snap disks on the contact part, which is evenly distributed in the circumferential direction.

According to a further embodiment, the first through hole is arranged centrally in the bimetal snap-action disk. Likewise, the second through hole is preferably arranged centrally in the spring snap-action disk.

The bimetal snap disk and the spring snap disk are preferably each designed in the shape of a circular disk. Furthermore, the bimetal snap disk and the spring snap disk are preferably each designed to be bistable.

In this respect, "bistable" means that both snap disks each have two different, stable geometric configurations/positions (used synonymously here), whereby the two stable configurations/positions of the bimetal snap disk are temperature-dependent and the two stable configurations/positions of the spring snap disk are temperature-independent. This means that the two snap disks, after they have snapped from one to the other, other position remain stable in the respective position without an unwanted snapping back occurring. The switching mechanism only snaps over if the response temperature of the bimetal snap disk is exceeded and the return temperature of the bimetal snap disk is undershot. The spring snap disk snaps together with the bimetal snap disk and is forced into its other configuration/position by this.

According to a further embodiment, the derailleur further comprises a derailleur housing which holds the bimetal snap disc, the spring snap disc and the contact part captive but with play.

This derailleur housing is not to be confused with the typical switch housing, which forms the outer housing of the switch. The derailleur housing used in this design is an additional housing in which the derailleur can already be arranged before it is installed in the switch outer housing.

In this way, the rear derailleur can already be pre-produced as a semi-finished product in the rear derailleur housing and then inserted into the switch housing together with the rear derailleur housing.

On the one hand, the derailleur housing has the advantage that the fragile components of the derailleur, such as the bimetal snap disk and the spring snap disk, are protected by the derailleur housing during storage. On the other hand, the additional derailleur housing makes it much easier to install the derailleur in the switch housing, as the derailleur housing already allows the derailleur to be pre-positioned. Furthermore, the additional derailleur housing makes it possible to create an extremely pressure-resistant switch.

The derailleur housing surrounds the bimetal snap disk and the spring snap disk from a first housing side, a second housing side opposite the first housing side and a side between and transverse to the first and the second housing side, preferably at least partially, wherein the first housing side has an opening through which the contact part is accessible from outside the derailleur housing.

The stationary contact that acts as a counterpart to the contact part can therefore continue to be arranged on the switch housing, since the contact part protrudes from the switch housing via the opening mentioned. A first electrical contact can thus take place between the contact part and the counter contact arranged on the switch housing. The second electrical contact between the switch and the second stationary contact, which is also arranged on the switch housing, can be established via the switch housing.

A diameter of the opening in the derailleur housing is preferably smaller than a diameter of the bimetal snap disk measured parallel to it.

The bimetal snap disc is thus securely held in the derailleur housing and cannot come loose even in the event of a shock.

The derailleur housing is preferably designed in one piece and comprises an electrically conductive material. The derailleur housing is particularly preferably designed from metal.

The switchgear housing is preferably used as a current-carrying component in the switch. The spring snap disc is preferably supported on the inside of the switchgear housing, so that when the switch is installed and in the closed switch position, the current flows from one connection of the switch via the switchgear housing, the spring snap disc and the contact part to the other connection of the switch.

As already mentioned, the present invention relates not only to the switching mechanism itself, but also to the temperature-dependent switch in which such a temperature-dependent switching mechanism is used. The temperature-dependent switch has a Switch housing surrounding the switching mechanism, which has a first electrical connection and a second electrical connection, wherein the switching mechanism is designed to establish an electrical connection between the first and the second electrical connection below a response temperature of the bimetallic snap disk and to interrupt the electrical connection when the response temperature is exceeded.

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

Fig. 1

eine schematische Schnittansicht des temperaturabhängigen Schaltwerks gemäß einem ersten Ausführungsbeispiel der vorliegenden Erfindung;

Fig. 2

eine schematische Schnittansicht des temperaturabhängigen Schaltwerks gemäß einem zweiten Ausführungsbeispiel der vorliegenden Erfindung;

Fig. 3

eine schematische Schnittansicht des temperaturabhängigen Schaltwerks gemäß einem dritten Ausführungsbeispiel der vorliegenden Erfindung;

Fig. 4

eine schematische Schnittansicht des temperaturabhängigen Schaltwerks gemäß einem vierten Ausführungsbeispiel der vorliegenden Erfindung;

Fig. 5

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

Fig. 6

eine schematische Schnittansicht des in Fig. 5 gezeigten Ausführungsbeispiels des erfindungsgemäßen temperaturabhängigen Schalters in seiner Hochtemperaturstellung; und

Fig. 7

eine schematische Darstellung zur Erläuterung eines Herstellungsschritts bei der Herstellung des erfindungsgemäßen Schaltwerks gemäß dem in Fig. 2 gezeigten zweiten Ausführungsbeispiel.

Embodiments of the invention are shown in the drawings and are explained in more detail in the following description. They show:

Fig. 1

a schematic sectional view of the temperature-dependent switching mechanism according to a first embodiment of the present invention;

Fig. 2

a schematic sectional view of the temperature-dependent switching mechanism according to a second embodiment of the present invention;

Fig. 3

a schematic sectional view of the temperature-dependent switching mechanism according to a third embodiment of the present invention;

Fig. 4

a schematic sectional view of the temperature-dependent switching mechanism according to a fourth embodiment of the present invention;

Fig. 5

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

Fig. 6

a schematic sectional view of the Fig. 5 shown embodiment of the temperature-dependent switch according to the invention in its high temperature position; and

Fig. 7

a schematic representation to explain a manufacturing step in the manufacture of the switching mechanism according to the invention according to the Fig. 2 shown second embodiment.

Fig. 1-4 show various embodiments of the switching mechanism according to the invention, each in a schematic sectional view. The switching mechanism is designated in its entirety with the reference number 10.

The switching mechanism 10 is a temperature-dependent switching mechanism. As explained in more detail below, the switching mechanism 10 switches between a low-temperature position and a high-temperature position depending on the temperature. In Fig. 1-4 the low temperature position of the switching mechanism 10 is shown.

The switching mechanism 10 is constructed in three parts. It has a temperature-dependent bimetal snap disk 12, a temperature-independent spring snap disk 14 and a contact part 16. The bimetal snap disk 12 and the spring snap disk 14 are held captive on the contact part, but with play. The switching mechanism 10 can thus be pre-produced as a semi-finished product and then used as a complete unit in a corresponding switch, as is the case, for example, in Fig. 5 and 6 shown. Since the two snap disks 12, 14 are held captive on the contact part 16, an unintentional release of the two snap disks 12, 14 from the contact part 16 is prevented.

The two snap disks 12, 14 are preferably designed in the shape of a circular disk, each having a centrally arranged through hole 18, 20. The through hole 18 arranged centrally in the bimetal snap disk 12 is referred to here as the first through hole. The through hole 20 arranged in the spring snap disk 14 is referred to as the second through hole.

The two snap disks 12, 14 are placed over the contact part 16 from opposite sides with their respective through holes 18, 20. The contact part 16 thus penetrates both snap disks 12, 14 at a central point. The contact part 16 has a base body 22, which is preferably solid and has an electrically conductive material. This base body 22 is guided through the two through holes 18, 20.

Approximately in the middle, i.e. approximately halfway up, the contact part 16 has a support shoulder 24 that projects radially from the base body 22. The two snap disks 12, 14 rest on this support shoulder 24 from opposite sides. The bimetal snap disk 12 is arranged on a first side of the support shoulder 24, which in Fig. 1-4 The spring snap disk 14 is arranged on a second side of the support shoulder 24 opposite the first side, which in Fig. 1-4 which forms the underside.

Furthermore, locking elements 26, 28 are formed on the contact part 16, with the aid of which the two snap disks 12, 14 are held on the contact part 16. The two locking elements 26, 28 protrude radially from the base body 22 of the contact part 16. The first locking element 26 is arranged on the first side of the support shoulder 24. The second locking element 28 is arranged on the opposite second side of the support shoulder 24.

The bimetallic snap disk 12 is arranged between the first locking element 26 and the support shoulder 24 and is held captive but with play on the base body 22 of the contact part 16 due to the radial projection of the first locking element 26 and the support shoulder 24 between the first locking element 26 and the support shoulder 24.

The spring snap disk 14 is arranged between the second locking element 28 and the support shoulder 24 and is held between the second locking element 28 and the support shoulder 24 due to the radial projection of the second locking element 28 and the support shoulder 24 are held captive but with play on the base body 22 of the contact part 16.

The contact part 16 is formed as a single piece together with the support shoulder 24 and the two locking elements 26, 28. In other words, the support shoulder 24 as well as the two locking elements 26, 28 are formed integrally with the base body 22 of the contact part 16.

In the Fig. 1 In the first embodiment shown, the two locking elements 26, 28 are each designed as a circumferentially encircling collar, which is formed by a circumferentially encircling cutting notch 30 or 32. The circumferentially encircling collar forming the first locking element 26 projects radially upwards from the base body 22 of the contact part 16 at an angle. The collar forming the second locking element 28 projects radially downwards from the base body 22 of the contact part 16 at an angle.

Both collars can be formed relatively easily by forming a circumferential cut notch 30 or 32 into the contact part 16. The cut notches 30, 32 are formed into the contact part 16 after the two snap disks 12, 14 with their through holes 18, 20 have been slipped over the base body 22 of the contact part 16.

In the Fig. 2 In the second embodiment shown, the locking elements 26, 28 each have at least one retaining claw 34 or 36. Both locking elements 26, 28 can have either a radially encircling retaining claw 34, 36 extending over the entire circumference of the contact part. Such encircling retaining claws then form very similar locking elements to those in Fig. 1 collar shown.

Alternatively, it is possible for both locking elements 26, 28 to each have a plurality of such holding claws 34, 36, which are arranged at a distance from one another in the circumferential direction on the contact part 16. There are then gaps between these individual, circumferentially distributed holding claws.

Regardless of whether the two retaining claws 34, 36 extend continuously over the entire circumference of the contact part or have several claw elements distributed over the circumference, the retaining claws 34, 36 are preferably manufactured by forming or flanging correspondingly pre-formed claw elements. Part of this manufacturing process is described in Fig. 7 shown schematically.

Fig. 7 shows in particular the flanging of the lower retaining claw 36, which later forms the second locking element 28, which serves to attach the spring snap disk 14 to the contact part 16. In the initial state, the pre-formed retaining claws 34, 36 protrude upwards or downwards in the axial direction from the base body 22. They are flanged by a suitable press stamp 38. This press stamp 38 has a bevel 40 arranged on the circumference at its radially outer end, with which the press stamp 38 contacts the retaining claw 36 during the forming process. A counterholder 42 acting as a counterpart to the press stamp 38 presses from the opposite side onto the support shoulder 24 of the contact part 16. The retaining claw 36 is thus bent or flanged by the press stamp 38. This is in Fig. 7 indicated by the arrows 44. During this process, the spring snap disk 14 preferably rests on a radially circumferential support surface 46.

The assembly and fixing of the bimetal snap disk 12 is carried out in an equivalent manner. To do this, the contact part 16 together with the spring snap disk 14 attached to it is turned 180° around an axis that is orthogonal to the plane of the sheet and the bimetal snap disk is slipped over the base body 22 of the contact part 16 so that it is arranged on the opposite side of the support shoulder 24 compared to the spring snap disk 14. The retaining claw 34 can then be bent radially outwards using the same press stamp 38 so that it is also finally attached to the contact part 16.

The base body 22 of the contact part 16 is preferably convexly shaped on its upper side 48. The contact part 16 is preferably designed such that a distance d ₁ between the upper side 48 and the lower side 50 of the contact part 16 is greater than a distance d ₂ between the first locking element 26 and the second locking element 28.

Preferably, at least the top side 48 of the contact part 16 projects upwards relative to the first locking element 26. This is particularly advantageous because the contact part 16 comes to rest with its top side 48 on a corresponding counter contact and the locking elements 26, 28 do not cause a collision with the counter contact.

Furthermore, it is advantageous for the function of the switching mechanism 10 if the bimetal snap disk 12 is held on the contact part 16 with greater play than the spring snap disk 14. This guarantees sufficient freedom of movement of the bimetal snap disk 12. At the same time, the slightly smaller play between the spring snap disk 14 and the contact part 16 guarantees the best possible electrical contact between these two components.

Fig. 3 and 4 show further embodiments of the switching mechanism 10 according to the invention. The design of the bimetal snap disk 12, the spring snap disk 14 and the contact part 16 corresponds to that in Fig. 1 In addition, the rear derailleur 10 has the features shown in Fig. 3 and 4 shown embodiments has a switching mechanism housing 52. In this switching mechanism housing 52, the unit consisting of the bimetal snap disk 12, the spring snap disk 14 and the contact part 16 is held captive, but with play.

The derailleur housing 52 at least partially surrounds the bimetal snap disk 12 and the spring snap disk 14 from a first housing side 54, a second housing side 56 opposite the first housing side 54 and a housing peripheral side 58 running between and transversely to the first and second housing sides 54, 56. On the first housing side 54, an opening 60 is provided in the derailleur housing 52 through which the contact part 16 is accessible from outside the derailleur housing 52.

A diameter D ₁ of the opening 60 is smaller than a diameter D ₂ of the bimetallic snap disk 12 measured parallel thereto. Thus, the contact part 16 is indeed accessible from the outside through the opening 60, but the bimetallic snap disk 12 cannot come out of the derailleur housing 52.

The derailleur housing 52 is preferably designed in one piece and consists of an electrically conductive material, for example metal. The derailleur 10 is preferably designed to be rotationally symmetrical about a longitudinal axis 62 of the contact part 16, both including and excluding the derailleur housing 52.

The two in Fig. 3 and 4 The embodiments of the derailleur 10 shown in FIG. 1 differ essentially in the shape of the derailleur housing 52. While the base 64 arranged on the second housing side 56 in the Fig. 4 The bottom 64 in the embodiment shown is curved in section and forms a kind of convex dome, the bottom 64 in the Fig. 3 shown embodiment is essentially plate-shaped and has a pot-like bulge 66 in a central section.

Of course, other shapes of the switchgear housing 52 are possible. However, it is important that the contact part 16 deviates from the position shown in Fig. 3 and 4 shown position can move downwards within the derailleur housing 52. The reason for this is particularly clear from the following explanations of the function of the Fig. 5 and 6 shown temperature-dependent switch.

In Fig. 5 and 6 an embodiment of a temperature-dependent switch in which the switching mechanism 10 according to the invention can be used is shown in a schematic sectional view. The switch is identified in its entirety with the reference number 100.

Fig. 5 shows the low temperature position of switch 100. Fig. 6 shows the high temperature position of switch 100.

The switch 100 has according to the Fig. 5 and 6 The embodiment shown has a switch housing 68 which acts as a housing for the rear derailleur 10. The rear derailleur 10 is inserted into the switch housing 68 together with its rear derailleur housing 52. The rear derailleur 10 corresponds to the Fig. 3 It is understood, however, that the embodiment shown in Fig. 4 The derailleur shown can be inserted in an equivalent form into the switch housing 68 of the switch 100. Likewise, a derailleur 10 without a derailleur housing 52, as is shown for example in Fig. 1 and 2 shown, can be inserted into the switch housing 68 of the switch 100 without changing the basic function of the switch 100.

The switch housing 68 comprises a pot-like lower part 70 and a cover part 72 which is held to the lower part 70 by a bent or flanged edge 74.

Both the lower part 70 and the cover part 72 are in the Fig. 5 and 6 In the embodiment shown, the housing is made of an electrically conductive material, preferably metal. An insulating film 76 is arranged between the lower part 70 and the cover part 72. The insulating film 76 ensures electrical insulation of the lower part 70 from the cover part 72. The insulating film 76 also ensures a mechanical seal that prevents liquids or contaminants from entering the housing interior from the outside.

Since the lower part 70 and the cover part 72 in this embodiment are each made of electrically conductive material, thermal contact can be made to an electrical device to be protected via their outer surfaces. The outer surfaces also serve as the external electrical connection of the switch 100. For example, the outer surface 71 of the cover part 72 can function as the first electrical connection and the outside 73 of the lower part 70 can function as the second electrical connection.

On the outside of the cover part 72, as shown in Fig. 5 and 6 shown, a further insulation layer 78 may be arranged.

The derailleur 10 is clamped between the lower part 70 and the cover part 72. A spacer ring 80, against which the derailleur housing 52 rests on the circumference, serves to position the derailleur 10. It is particularly important that the contact part 16 is aligned with a counter contact 82, which is arranged on the inside of the cover part 72. This counter contact 82 is also referred to here as the first stationary contact. The inside 75 of the lower part 70 serves as the second stationary contact.

In the Fig. 5 In the position shown, the switch 100 is in its low-temperature position, in which the temperature-independent spring snap disk 14 is in its first configuration and the temperature-dependent bimetallic snap disk 12 is in its low-temperature configuration. The spring snap disk 14 presses the contact part 16 against the counter contact 82. The switch 100 is thus in its closed position, in which an electrically conductive connection is established between the first stationary contact 82 and the second stationary contact 75 via the contact part 16 and the spring snap disk 14. The contact pressure between the contact part 16 and the first stationary contact 82 is generated by the spring snap disk 14. The bimetallic snap disk 12, on the other hand, is almost force-free in this state.

If the temperature of the device to be protected and thus the temperature of the switch 100 and the bimetal snap-action disk 12 arranged therein increases to the switching temperature of the bimetal snap-action disk 12 or beyond this switching temperature, the latter snaps from its Fig. 5 shown, convex low-temperature configuration into its concave high-temperature configuration, which is Fig. 6 is shown. During this snapping, the bimetal snap disk 12 rests with its outer edge on the first housing side 54 of the switchgear housing 52. With its center, the bimetal snap disk 12 pulls the movable contact part 16 downwards and lifts the movable contact part 16 off the first stationary contact 82. As a result, the spring snap disk 14 bends downwards at its center at the same time, so that the spring snap disk 14 is released from its Fig. 5 shown, first stable geometric configuration into its Fig. 6 shown second geometrically stable configuration snapped. Fig. 6 shows the high temperature position of switch 100, in which it is open. The circuit is thus interrupted.

If the switching mechanism 10 does not have a switching mechanism housing 52, the bimetallic snap disk 12 is supported on the cover part 72 in the high-temperature position of the switch 100 with the insulating film 76 in between.

When the device to be protected and thus the switch 100 together with the bimetal snap-action disk 12 cool down again, the bimetal snap-action disk 12 snaps back into its low-temperature position when the switch-back temperature, which is also referred to as the return temperature, is reached, as is the case, for example, in Fig. 5 This allows a reversible switching behavior to be realized.

Of course, it is also possible for a corresponding locking device to prevent the switch from switching back once it has snapped into the high-temperature position. A large number of locking devices of this type, which are used in particular in one-time switches where switching back is to be prevented, are already known from the prior art.

Finally, it should be noted that the switching mechanism 10 according to the invention, as shown for example in Fig. 1-4 shown in different embodiments, can also be used in other types of temperature-dependent switches. Fig. 5 and 6 show only one possible design of a temperature-dependent switch in which the switching mechanism 10 according to the invention can be used.

Claims (14)

1. A temperature-dependent switching mechanism (10) for a temperature-dependent switch (100), having:

   - a temperature-dependent bimetal snap-action disc (12) comprising a first through hole (18);

   - a temperature-independent snap-action spring disc (14) comprising a second through hole (20); and

   - an electrically conductive contact member (16) comprising a main body (22) that passes through the first through hole (18) and the second through hole (20);

   wherein the contact member (16) comprises a support shoulder (24) projecting radially from the main body (22), a first locking element (26) projecting radially from the main body (22) and being arranged on a first side of the support shoulder (24), and a second locking element (28) projecting radially from the main body (22) and being arranged on a second side of the support shoulder (24) opposite the first side,

   wherein the temperature-dependent bimetal snap-action disc (12) is arranged between the first locking element (26) and the support shoulder (24) and is held captive, but with clearance, on the main body (22) of the contact member (16) by the first locking element (26) and the support shoulder (24),

   wherein the temperature-independent snap-action spring disc (14) is arranged between the second locking element (28) and the support shoulder (14) and is held captive, but with clearance, on the main body (22) of the contact member (16) by the second locking element (28) and the support shoulder (24),

   characterized in that the contact member is integrally formed and the main body (22) is integrally connected to the support shoulder (24), the first locking element (26) and the second locking element (28).
2. The temperature-dependent switching mechanism according to claim 1, wherein the first locking element (26) comprises at least one first retaining claw (34) projecting radially from the main body (22) and formed integrally therewith, or a first collar projecting radially from the main body (22) and surrounding the circumference of the main body (22), and wherein the second locking element (28) comprises at least one second retaining claw (36) projecting radially from the main body (22) and formed integrally therewith, or a second collar projecting radially from the main body (22) and surrounding the circumference of the main body (22).
3. The temperature-dependent switching mechanism according to any one of the preceding claims, wherein a first distance (d₁) between an upper side (48) of the contact member (16) arranged on the first side of the support shoulder (24) and a lower side (50) of the contact member (16) arranged on the second side of the support shoulder (24) is larger than a second distance (d₂) between the first locking element (26) and the second locking element (28).
4. The temperature-dependent switching mechanism according to any of the preceding claims, wherein the bimetal snap-action disc (12) is held on the main body (22) with larger clearance than the snap-action spring disc (14).
5. The temperature-dependent switching mechanism according to any one of the preceding claims, wherein the switching mechanism (10) is configured rotationally symmetrical about a longitudinal axis (62) of the contact member (16).
6. The temperature-dependent switching mechanism according to any one of the preceding claims, wherein the first through hole (18) is arranged centrally in the bimetal snap-action disc (12), and wherein the second through hole (20) is arranged centrally in the snap-action spring disc (14).
7. The temperature-dependent switching mechanism according to any of the preceding claims, wherein the bimetal snap-action disc (12) and the snap-action spring disc (14) are each circular disc-shaped.
8. The temperature-dependent switching mechanism according to any one of the preceding claims, wherein the snap-action spring disc (14) is configured as a bistable snap-action spring disc (14) having two temperature-independent stable geometric configurations, and wherein the bimetal snap-action disc (12) is configured as a bistable bimetal snap-action disc (12) having two temperature-dependent stable geometric configurations.
9. The temperature-dependent switching mechanism according to any of the preceding claims, having a switching mechanism housing (52) which holds the bimetal snap-action disc (12), the snap-action spring disc (14) and the contact member (16) captive but with clearance.
10. The temperature-dependent switching mechanism according to claim 9, wherein the switching mechanism housing (52) surrounds the bimetal snap-action disc (12) and the snap-action spring disc (14) from a first housing side (54), a second housing side (56) opposite the first housing side (54), and a housing peripheral side (58) extending between and transverse to the first and second housing sides, the first housing side (54) having an opening (60) through which the contact member (16) is accessible from outside the switching mechanism housing (52).
11. The temperature-dependent switching mechanism according to claim 10, wherein a diameter (D₁) of the opening (60) is smaller than a diameter (D₂) of the bimetal snap-action disc (12) measured parallel thereto.
12. The temperature-dependent switching mechanism according to any one of claims 9-11, wherein the switching mechanism housing (52) is integrally formed and comprises an electrically conductive material.
13. A temperature-dependent switch (100) comprising a temperature-dependent switching mechanism (10) according to any one of claims 1-12 and a switch housing (68) surrounding the switching mechanism (10) and comprising a first electrical terminal (71) and a second electrical terminal (73), wherein the switching mechanism (10) is configured to establish an electrical connection between the first and second electrical terminals (71, 73) below a response temperature of the bimetal snap-action disc (12) and to interrupt the electrical connection upon exceeding the response temperature.
14. A method of manufacturing a temperature-dependent switching mechanism (10) comprising:

    - providing a temperature-dependent bimetal snap-action disc (12) comprising a first through hole (18);

    - providing a temperature-independent snap-action spring disc (14) comprising a second through hole (20);

    - providing an electrically conductive contact member (16) comprising a main body (22) and a support shoulder (24) projecting radially from the main body (22);

    - passing the main body (22) through the first through hole (18) so that the bimetal snap-action disc (12) is arranged on a first side of the support shoulder (24);

    - passing the main body (22) through the second through hole (20) so that the snap-action spring disc (14) is arranged on a second side of the support shoulder (24) opposite the first side;

    - forming a first portion of the main body (22) arranged on the first side of the support shoulder (24) to create a first locking element (26) such that the temperature-dependent bimetal snap-action disc (12) is arranged between the first locking element (26) and the support shoulder (24) and is held captive, but with clearance, to the main body (22) of the contact member (16) by the first locking element (26) and the support shoulder (24); and

    - forming a second portion of the main body (22) arranged on the second side of the support shoulder (24) to create a second locking element (28) such that the temperature-independent snap-action spring disc (14) is arranged between the second locking element (28) and the support shoulder (24) and is held captive, but with clearance, to the main body of the contact member (16) by the second locking element (28) and the support shoulder (24).

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