EP3685417B1 - Thermally triggerable indicating or switching device - Google Patents

Description

The invention is based on a thermally triggered display or switching device with a movable, mechanically pretensionable slide, which directly or indirectly triggers or actuates the display or switching device and with a molded part that changes its physical state under the action of heat, the molded part being the movable slider in the functional state can be arranged blocking, according to the preamble of claim 1.

From the DE 10 2017 105 436 B3 a thermally triggered, mechanical switching device is previously known. This consists of a heat-sensitive means and a mechanical energy store, the heat-sensitive means being designed as a molded melt part. The molded part blocks the movement path of a contact piece implemented as a plunger or releases this movement path. The ram is pretensioned by the mechanical energy store. There is also a housing which accommodates the aforementioned means. The plunger is mounted inside the housing and can be moved through an opening on the face. The plunger is supported under prestress against the molded melt part, the molded melt part being arranged to cover a second opening opposite the opening on the end face. When the melting temperature of the molded melt part is reached, the same is displaced by the plunger and the plunger is brought into a changed position. As a result, a display or switching device can be triggered directly or indirectly.

In the case of the surge arrester with at least one discharge element, for example a varistor, and a disconnection device according to FIG DE 10 2006 037 551 B4 the at least one discharge element should be disconnected from the network on one or all poles.

The disconnection device comprises a soldering point which is integrated into the electrical connection path within the arrester. The soldering point is connected to the diverting element on the one hand and the conductor section or the bridge on the other hand to an electrical external connection of the diverter via a movable conductor section or a movably conductive bridge. Furthermore is a There is a spring generating a biasing force, the force vector in this regard acting directly or indirectly on the conductor section or the bridge in the separation direction.

A thermally releasable blocking element blocks the movable conductor section or the movable conductive bridge with regard to the prestressing force vector, so that the soldering point of the separating device is not exposed to any permanent load on the force side.

With the solution after DE 10 2006 037 551 B4 it can therefore be prevented that the thermally activatable element, for example designed as a soldering bead, is subject to mechanical stress over the entire period of use, starting with the manufacture of a corresponding product. However, the solution presented is structurally very complex and therefore cost-intensive.

From the LU 93090 B1 a separating device is known which comprises at least two electronic components to be monitored, which are fastened to a carrier by means of a thermally softenable fixation. An energy storage device is assigned to each component, for example a spring, which moves the associated component essentially parallel to the carrier when the thermally softenable fixation softens. The separating device further comprises a mechanically displaceable display means which indicates when one or more of the components have been separated.

the DE 22 20 264 A1 describes an overheating protection or display device comprising a switch and a retaining element which melts at a higher temperature. Furthermore, a switch body is provided which is brought into engagement with the switch by means of a spring when the holding element melts.

From the above, the object of the invention is to provide a thermally triggered display or switching device with a movable, mechanically preloaded slide and with a molded part that changes its physical state under the action of heat, which can be produced in a simple and inexpensive manner, and there is the possibility that a The device can be activated subsequently, that is, independently of the actual assembly and manufacturing process. There should therefore be the possibility that the to bring the thermal release function into readiness only when a use of the component or component equipped with it is intended or has taken place.

The aim of the invention is therefore to allow the customer to enable the display or switching device, as it were, thereby avoiding at the same time that the molded part used is exposed to an unnecessary load that arises in advance.

The object of the invention is achieved with the combination of features according to claim 1 and with a surge arrester arrangement according to claim 8.

Accordingly, a thermally triggered display or switching device is assumed which comprises a movable, mechanically pretensioned slide.

The slide can directly or indirectly trigger or actuate the display or switching device.

The slide itself can be located as an insulating separating slide between two contacts and either interrupt or close them. However, the slide can also actuate a known micro-button or the like.

The display device can be designed in the form of a display surface, which is located below a display window and uses an optical color change. Of course, professional modifications of the display and / or switching device are conceivable here without departing from the basic idea of the invention.

There is also a molded part that changes its physical state under the action of heat. The molded part can be, for example, a pill or a similar element made from a solder, a wax or a thermoplastic material.

In the functional state, the molded part is arranged in such a way that it blocks the movable slide.

According to the invention, in the initial state, that is to say on the production side, the molded part is loosely located in a receiving space.

To bring the molded part into the functional state, the slide is moved into a position such that a gap opens between the slide and a slide stop.

This can be a gap between the slide and a carrier, for example a base plate of the corresponding device.

Supported by an elastic or resilient arm connected to the slide, the molded part now enters the gap. By moving the slide into the position for the formation of the gap, the slide is pretensioned at the same time. This can be done with a spring arrangement.

After the molded part has been transferred into the gap space and the slide is subject to the pretensioning, the slide comes into contact with the molded part with its end facing the gap space and fixes it. The elastic or flexible arm now secures the molded part in the gap against being pushed out or falling out.

If there is now a temperature increase in the area of the gap, that is, in the space in which the molded part is located, it can change its physical state when it reaches its melting temperature. As a result, the pretensioning force of the slide acts on the molded part. The stop, which is no longer rigid, extends the movement path of the slide, so that the gap is gradually reduced further, while displacing the molded part material into an existing free space.

The result is that the corresponding display or switching device is now triggered.

To support the movement of the preformed solder part for the purpose of activating the display or switching device, the arm has an inclined sliding surface. This inclined sliding surface is particularly advantageous when the molded part has the shape of a disk, a pill or a ball. In any case, it is ensured here that when the device is activated, the molded part can be safely transferred into the gap space and also remains there, regardless of mechanical vibrations and similar loads.

In an embodiment of the invention, at least one guide element can be formed adjacent to the arm in order to secure and support the movement of the molded part into the gap space.

In a further development of the invention, the slide has an extension which merges into a display area or comprises such a display area.

The extension can also be used to operate a switch at the same time.

When the molded part is heated, for example due to heat loss from neighboring electronic components, the molded part melts or changes its state of aggregation.

This narrows the gap, supported by the pretensioned slide with the consequence of a change in the position or the state of the display or switching device.

With the melting of the molded part and the change in position of the slide, a first switch can be closed and a second switch can be opened. Of course, this can be implemented the other way around, in that a first switch is opened and a second switch is closed. It is also possible to design a switch as a changeover contact.

The teaching according to the invention allows the display and switching device to be activated individually and with a time delay, that is to say only in the case of use, as a result of which unnecessary mechanical stress on the molded part can be prevented regardless of any storage times.

According to the invention, there is also a surge arrester arrangement with at least one surge protection element, which is subject to heating in the event of an overload, comprising the aforementioned thermally triggered display or switching device with the features described above.

The invention is to be explained in more detail below using an exemplary embodiment and with the aid of figures.

• Figur 1 eine vereinfachte Darstellung der erfindungsgemäßen Einrichtung im Ausgangszustand nach Montage mit lose eingelegtem Formteil und noch nicht gespannter Feder;
• Figur 2 eine Darstellung ähnlich derjenigen nach Figur 1, jedoch mit angedeutetem Bewegungsvorgang zum Aktivieren der Einrichtung, wobei das Formteil in Richtung Spaltraum bewegt und gleichzeitig die Feder gespannt wird;
• Figur 3 eine Darstellung ähnlich derjenigen nach den Figuren 1 und 2, jedoch mit dem Formteil in seiner Endposition, das heißt im Spaltraum befindlich, gespannter Feder bzw. aktiviertem Schalter; und
• Figur 4 eine Darstellung ähnlich derjenigen nach Figur 3, jedoch im Zustand der ausgelösten Anzeige- und Schalteinrichtung durch Wärmeeinwirkung, welche das Formteil in seinem Aggregatzustand ändert, wobei der Schieber aufgrund der Federvorspannung unter Endspannung der Feder das Formteil verdrängt hat mit dem Ergebnis eines geänderten Anzeigezustandes sowie einem geänderten Zustand der symbolisch dargestellten Schalter.

Here show:

• Figure 1 a simplified representation of the device according to the invention in the initial state after assembly with loosely inserted molded part and not yet tensioned spring;
• Figure 2 a representation similar to that after Figure 1 , but with an indicated movement process for activating the device, the molded part being moved in the direction of the gap space and the spring being tensioned at the same time;
• Figure 3 a representation similar to that after Figures 1 and 2 , but with the molded part in its end position, that is located in the gap, tensioned spring or activated switch; and
• Figure 4 a representation similar to that after Figure 3 , but in the state of the triggered display and switching device by the action of heat, which changes the physical state of the molded part, whereby the slide has displaced the molded part due to the spring preload under the final tension of the spring, resulting in a changed display state and a changed state of the symbolically represented switch.

The thermally triggerable display or switching device according to the invention, shown in more detail in the following exemplary embodiment, is based on a carrier 1 which has a stop and guide element 2 for a movable slide 3.

The slide 3 has an extension 4 which merges into a display area 5.

One end of the extension 4 is also able to operate a first switch 6 and a second switch 7, that is, to open or close, which is symbolically illustrated by the action of operating elements 8 and 9 for the switches 6 and 7 .

An at least partially flexible or elastic, angled arm 10, which is connected to the slide 3 or the extension 4, in connection with a leg section of the slide 3, delimits a receiving space 11 for a molded part 12, for example a preformed solder part. The molded part 12 can be inserted into the receiving space 11 from above. Furthermore, a guide element 13 is arranged within the receiving space 11. The slide 3 can be pretensioned using a spring 14. In the exemplary embodiment shown, the spring 14 is located within a cavity of the slide 3. Of course, alternative options for the arrangement of the spring 14 in relation to the slide 3 are also possible here.

To activate the device according to the invention, according to Figure 2 the slide 3, for example with the aid of a force acting on the extension 4, moves in the direction X1.

Here, under the action of the now slightly yielding arm 10 and supported by the guide element 13, the preformed solder part 12 enters the gap 15 created by the slide movement, symbolized by the arrow in the direction Y1. During this movement of the slide in the direction X1, the spring 14 is also tensioned at the same time.

By changing the position of the slide, the position of the extension 4 and that of the display surface 5 including the elements 8 and 9 of the switches 6 and 7 also change, which is also shown in the illustration Figure 2 is understandable.

According to Figure 3 the molded part 12 is now located completely in the gap 15. A movement of the molded part 12 in the direction Y2, that is to say out of the gap 15, is prevented by the position of the arm 10.

After the corresponding heat action on the molded part 12, that is to say when, for example, the melting temperature of a solder from which the molded part is made is reached, the molded part changes its state of aggregation. This is supported by the quasi-stamp-like action of the slide 3 in addition to the force from the spring 14.

The consequence of the movement of the slide in direction X2 is, in turn, a change in the position of the display surface 5 and a change in the functional state of the first switch 6 or the second switch 7.

The necessary thermal energy for deforming the molded part 12 can be supplied via the element 2, in which case the element 2 is made in particular from a material which forms a heat sink.

Claims (8)

1. A thermally triggerable indicating or switching device comprising a movable, mechanically preloaded slide (3) which directly or indirectly triggers or actuates the indicating or switching device (5, 6, 7), and comprising a preformed part (12) which changes its state of aggregation under the effect of heat, the preformed part (12), in the functional state, being adapted to be arranged so as to block the movable slide (3),

   characterized in that

   in the initial state, the preformed part (12) is loosely located in a receiving space (11), the slide (3) being moved to a position for transferring the preformed part (12) to the functional state such that a gap space (15) opens between the slide (3) and a slide stop (2),

   wherein, supported by an elastic or flexible arm (10) connected to the slide (3), the preformed part enters the gap space (15) and the slide (3) is preloaded, and the elastic or flexible arm (10) thus secures the preformed part (12) in the gap space (15).
2. The thermally triggerable indicating or switching device according to claim 1, characterized in that the arm (10) has an inclined sliding face (100) for supporting the movement of the preformed part (12) to activate the indicating or switching device (5, 6, 7).
3. The thermally triggerable indicating or switching device according to claim 1 or 2, characterized in that at least one guiding element (13) is formed adjacent to the arm (10) to ensure the movement of the preformed part (12) into the gap space (15).
4. The thermally triggerable indicating or switching device according to any of the preceding claims, characterized in that the slide (3) includes a projection (4) which has an indicating area and/or a switch actuating member.
5. The thermally triggerable indicating or switching device according to any of the preceding claims, characterized in that the preformed part (12) melts when the preformed part (12) is heated, for example due to heat loss of adjacent electronic components, as a result of which the gap space (15) narrows supported by the preloaded slide (3), which leads to a change in the position or state of the indicating or switching device (5, 6, 7).
6. The thermally triggerable indicating or switching device according to claim 5, characterized in that with the melting of the preformed part (12) and the change in position of the slide (3), a first switch (6) closes and a second switch (7) opens, or vice versa.
7. The thermally triggerable indicating or switching device according to any of the preceding claims, characterized in that the activation of the indicating or switching device (5, 6, 7) is carried out individually and in a deferred manner, i.e. only in the case of use.
8. A surge arrester arrangement comprising at least one surge protection element which is subject to heating in case of overstress, comprising a thermally triggerable indicating or switching device (5, 6, 7) according to any of the preceding claims.

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