EP0730285A1 - Insulating housing - Google Patents

Abstract

An electrical temp. sensitive switching device Ä17Ü is in an encapsulated form and is installed between contact elements Ä24, 25Ü that project from the housing of an electrical equipment. The capsule is formed with a recess Ä33Ü that is engaged by a projection Ä34Ü on the upper contact arm. The lower contact arm also has a projecting lug Ä32Ü. When the capsule is positioned between the contact arms a housing Ä10Ü of insulating material is fitted to enclose the assembly. The internal surface of the housing has features Ä21, 31Ü that engage the contact arms.

Description

The present invention relates to an insulating housing with an interior for receiving a mechanically and / or electrically protected switch with a temperature-dependent switching mechanism, the switch having two electrically conductive connection surfaces via which an electrical connection of the switch to contact parts of a holder or an electrical to be protected Consumer.

Such an insulating housing is known from DE 38 17 080 A1.

This publication describes a temperature monitor in which a switch with a temperature-dependent switching mechanism is arranged in an insulating housing. The insulating housing is designed so that it can be plugged onto connections of a consumer to be monitored, two connections also protruding from the insulating housing of the temperature monitor, which correspond to a desired connection diagram. In the consumer known from this document, there is no standardized connection diagram, so that it cannot be supplied with current via a standardized plug. The implementation of the connection diagram of the consumer on the standardized connection diagram takes place via the insulating housing, in which there are intricately bent sheet metal parts which, on the one hand, contact the housing of the switching mechanism and, on the other hand, form connecting lugs or mating connectors for the connecting lugs of the consumer or standardized connector.

Because of the required connection technology, which connects the switching mechanism in the interior of the insulating housing to the external connections, the known temperature monitor is a very cost-intensive component, since the connection technology can generally only be accomplished by hand.

A switch with a temperature-dependent switching mechanism, such as can be used for the purpose of the present invention, is known from DE 29 17 482 C2. The switch has a closed housing in which the switching mechanism is arranged. The housing comprises an electrically conductive cover and an electrically conductive lower part which is insulated from the cover. The electrical connection of the switch in the installed state takes place directly over the cover and the lower part.

Such switches, which are also called temperature monitors, are used to monitor the operating temperature and / or the operating current of the electrical consumer to be protected. If the operating temperature of the consumer exceeds a certain limit, the switch opens, which must be connected in series with the consumer in the supply circuit for this purpose. By means of parallel and / or series resistors provided on the switch, such switches can be designed to be self-holding and, if necessary, also when the current switching is too high if the series resistance heats up too much.

Such consumers are generally known from the prior art. Especially in household appliances, more and more devices with electrical consumers are being used, such as. B. drain pumps for washing machines, motors for compressors in refrigerators and freezers, transformers for electrical devices that are operated with a voltage different from the mains voltage, fan motors and heating coils for hair dryers, etc.

For safety reasons, there is an increasing tendency to monitor the temperature development of the consumers and to switch them off if the heating is too high. For this purpose, temperature monitors are used, which have their own housing or support part and are subsequently installed on the consumer. In these guard housings there are Bimeta11 switchgear assemblies, which are usually connected to two terminal lugs, terminals or strands that are located on the guard housing itself. Such a connection element of the temperature monitor is connected to a corresponding connection element of the consumer, wherein the second connection element of the temperature monitor and the second connection element of the consumer then serve for the electrical supply to the consumer, which is now connected in series with the temperature monitor.

Such temperature monitors are usually special developments that must be adapted to the consumer to be protected. It is not only important to pay attention to the connection technology, but also to ensure good thermal contact with the consumer to be monitored. As a result, the costs for the design and manufacture of such temperature monitors are very high. Naturally, these costs are also transferred to the end costs of the consumers protected by the temperature monitor.

Another cost factor is the installation of the temperature monitor on the consumers to be protected, unless the plug-in technology mentioned above is used. Frequently, strands have to be soldered or inserted into clamping blocks during this assembly, which also requires labor-intensive manual work.

From DE 90 04 941 U a temperature monitor is known which has a frame made of plastic, onto which an electrically conductive contact plate is snapped on from above and from below. A bimetallic switching mechanism is arranged in the frame and is clamped between the contact plates. The contact is made by placing the upper contact plate on the cover and the lower contact plate on the bottom of the rear derailleur.

On the frame locking projections are provided, which are overlapped by hook-like tabs of the contact plates, so that these detents exert pressure from above and below on the switching mechanism.

When assembling the temperature monitor, the upper contact plate is first snapped onto the frame before the switching mechanism is inserted into the frame from the underside. Finally, the lower contact plate is placed from below, so that the switching mechanism is held clamped between the two contact plates, the latching projections of the frame part forming the abutments for the clamping forces.

In the known holder and the temperature monitor assembled therefrom, it is disadvantageous that the mechanical tolerances of the sheet metal parts and the plastic frame must be very small so that the required contact forces can be applied. However, since these temperature monitors are mass-produced items, the sheet metal parts and plastic frames are manufactured in very large numbers, whereby the tolerances are not always met. Furthermore, these individual parts are supplied to the manufacturers in large batches, and it often happens that sheet metal parts in the batch bend during transport or pouring operations.

All this leads to the fact that there is a high level of rejects when assembling the known temperature monitor, which overall increases the manufacturing costs of the temperature monitor.

Another disadvantage of the known temperature monitor is in connection with the required contact reliability between the bimetallic switching mechanism and the contact plates forming the external connections. Since the contact forces are applied through non-curved lugs of the contact plates, this contacting often does not meet the long-term requirements, because the high loads in everyday operation, e.g. B. by continuous vibrations of the devices protected by the temperature monitor, weaken the locking connection. Especially when the tolerances of the mated Components add up unfavorably, contact reliability can no longer be guaranteed after a short period of operation.

It is generally known that the connection technology, that is to say the connection of the possibly encapsulated bimetal switchgear with the external connections, is very labor-intensive in the manufacture of such temperature monitors and requires the storage of many individual parts. Furthermore, the known temperature monitor or its holder can only be assembled manually, which not only entails high costs, but also further increases the reject rate.

Proceeding from this, it is an object of the present invention to further develop the insulating housing mentioned at the outset in such a way that the insulating housing containing a temperature-dependent switch can be installed quickly and inexpensively on an electrical consumer with little structural effort.

According to the invention, this object is achieved in the insulating housing mentioned at the outset in that it has at least one opening through which the contact parts come into direct contact with the two connection surfaces and clamp the switch between them.

The object underlying the invention is completely achieved in this way.

The insulating housing is now designed so that the switch only has to be inserted, whereupon the insulating housing is then pushed onto contact parts of an electrical consumer. These contact parts come into contact with the two connection surfaces and thus contact the one in the Temperature-dependent switching mechanism provided inside the switch. The switch can be inserted mechanically into the insulating housing, it also being possible for the switch to be extrusion-coated with a correspondingly shaped insulating housing. Not only the production but also the final assembly and the attachment to the electrical consumer to be protected or to a holder provided for this purpose are thus very simple, can be automated and are therefore inexpensive and fail-safe.

Accordingly, the electrical consumer mentioned is equipped so that two contact parts form a receptacle for the switch, one of the two connection elements and one of the two contact parts are connected to the consumer and the other contact part is connected to the other connection element.

The necessary "wiring" of the consumer can thus take place before the temperature monitor is installed, which only has to be pushed onto the two contact parts with its insulating housing.

The new insulating housing thus creates an extremely simple connection technology, which can be implemented inexpensively and with little waste.

It is then preferred if the insulating housing has an inner profile through which the inserted contact parts are pressed onto the connection surfaces.

The advantage here is that it is not the spring force of the contact parts that is decisive for the contact security, but that the contacting is at least supported by the inner profile of the insulating housing.

It is further preferred if the insulating housing has at least one locking element, via which it locks with an assigned locking element on one of the contact parts.

It is advantageous here that the insulating housing and thus the switch accommodated therein are held captively on the electrical consumer, this holding force being independent of the contacting force between the contact parts and the connection surfaces.

It is further preferred if the insulating housing holds a received switch captively, for which purpose it preferably has latchable means which can be pushed over and which hold a received switch captively.

The advantage here is that a temperature monitor consisting of an insulating housing and switch can be preassembled, the switch only has to be inserted into the insulating housing, where it is held captively by the overpressed locking elements. Such temperature monitors can then be transported as bulk goods, since the switch is mechanically protected by the insulating housing surrounding it. Of course, this insertion of the switch into the insulating housing can be accomplished by automatic manufacturing machines.

It is then further preferred if the insulating housing has guide channels or grooves for the contact parts, the guide channels or grooves preferably having a guide surface which is inclined in the longitudinal direction toward the interior or a guide surface which is curved in the longitudinal direction.

This measure is particularly advantageous in terms of construction, because the guide surfaces advantageously provide for one corresponding contact pressure that the contact parts exert on the connection surfaces of the switch. However, the guide channels and / or grooves have the further advantage that the contact parts are guided when the insulating housing is pushed on, so that they cannot buckle or break off.

Overall, it is preferred if the insulating housing has a further opening for pushing the switch into the interior, the further opening preferably running perpendicular to the guide channels and / or grooves.

This measure has the advantage that the switch is not only contacted by the contact parts inserted into the guide channels or grooves, but is also prevented from falling out of the insulating housing. This can either be completely dispensed with further locking means that hold the switch in an insulating housing that has not yet been mounted on a consumer, or it is possible to use locking means that can be easily overridden, which are only for the transport of an insulating housing that has not yet been mounted on a consumer ensure safe mechanical coldness of the switch inside the insulating housing. Overall, this not only simplifies the construction of the new insulating housing, it also greatly simplifies the individual assembly steps required.

It is preferred if the insulating housing is made entirely of insulating material and is preferably a plastic injection molded part.

The advantage here is that the insulating housing can be manufactured in one piece in a very simple, inexpensive injection molding process.

In the case of the electrical consumer, it is also advantageous if the two contact parts with their broad sides are facing connection lugs, onto which a new insulating housing with a switch accommodated therein can be plugged, so that very inexpensive, also otherwise used, connecting lugs can be used to isolate the housing and switches to contact existing temperature monitors electrically and to hold them mechanically.

In general, the insulating housing can be designed in such a way that the received switch is held loosely or is clamped firmly by the latching means. The switch is then contacted only by inserting the contact parts or connecting lugs of a holder or electrical consumer into the insulating housing, the insulating housing itself ensuring that the contact parts are pressed onto the contact surfaces of the switch and held there immovably by the internal shape.

Further features and advantages result from the description below.

It goes without saying that the features mentioned above and those yet 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

in einer Seitenansicht eine Explosionsdarstellung von neuem Isoliergehäuse, Schalter und Halter;

Fig. 2

eine von rechts gesehene Draufsicht auf das Isoliergehäuse aus Fig. 1; und

Fig. 3

in einer Darstellung wie Fig. 1 ein weiteres Isoliergehäuse mit einem aufgenommenen Schalter sowie einem zugeordneten Verbraucher.

The invention is illustrated in the drawing and is explained in more detail in the following description. Show it:

Fig. 1

an exploded view of a new insulating housing, switch and holder in a side view;

Fig. 2

a top view of the insulating housing from FIG. 1 seen from the right; and

Fig. 3

in a representation like FIG. 1, a further insulating housing with an incorporated switch and an associated consumer.

In Fig. 1, generally 10 denotes a new insulating housing which has an interior 11 for receiving a switch 12 with a temperature-dependent switching mechanism.

The switch 12 shown on the right next to the insulating housing 10 in FIG. 1 has an upper connection surface 13 and a lower connection surface 14, which are part of an electrically conductive cover part 15 or an electrically conductive lower part 16, which insulates the cover part 15 in a known manner is. Cover part 15 and lower part 16 form an encapsulated housing 17 in which the temperature-dependent switching mechanism is arranged in a known manner.

The insulating housing 10 has an opening 18 in which pressable locking means 19 in the form of locking lugs 21 and 22 are arranged. Through this opening 18, the switch 12 can be pushed into the interior 11, where it is then held captively but loosely by the detents 21 and 22.

In Fig. 1, a holder 23 is shown on the right, which is part of a consumer or is suitable to be connected to a consumer to be protected. The holder 23 has two contact parts 24, 25, which are terminal lugs 26, 27 here. The connecting lugs 26, 27 point towards one another with their broad sides and are at a clearance 28 from one another which corresponds to the thickness or height of the switch 12 indicated at 28 '.

The opening 18 of the insulating housing 10, on the other hand, has an internal width 29 which is dimensioned such that the connecting lugs 26, 27 can also be inserted into the insulating housing 10 when the switch 12 is located in the interior 11.

In the interior 11 of the insulating housing 10 there is also a latching element 31 in the form of a depression, with which a further latching element 32 on the connecting lug 27 interacts in such a way that an insulating housing 10 pushed onto the connecting lugs 26, 27 is held captively.

Two further latching elements 33, 34 are arranged in the cover part 15 of the switch 12 or on the connecting lug 26 such that a further captive mounting of the insulating housing 10 is realized on the holder 23 via the switch 12 held captively therein.

After the assembly just described has taken place, the terminal lug 26 rests on the cover part 15, while the terminal lug 27 bears against the lower part 16. In order to increase the electrical contact between the connection surfaces 13, 14 and the connection lugs 26, 27, the insulating housing 10 has guide bevels 35, 36 which run inclined into the interior 11. By means of these guide bevels 35, 36, the connection lugs 26, 27 are pressed onto the connection surfaces 13, 14, so that the electrical contact between these parts is further improved. Due to the applied forces, however, the insulating housing 10 is not pushed away again from the holder 23, since a captive mounting is realized via the latching elements 31, 32, 33, 34, as has already been described above.

In Fig. 2 it can still be seen that between the locking lugs 21 and 22 guide channels or guide grooves 37, 38 are formed, through which the terminal lugs 26, 27 are guided when the insulating housing 10 is pushed on.

The insulating housing 10 is a one-piece injection molded plastic part 39, which can be produced very inexpensively as a corresponding mass article.

3 shows a further insulating housing 41, in the interior 42 of which a switch 12 is indicated. The switch 12 is held firmly in the interior 42 by a locking lug 43, which acts in the same way as the locking lugs 21, 22 in the insulating housing 10. For locking, the switch 12 is pushed into the interior 12 through an opening 44 from below until the latch 43 is suppressed. The interior 42 can then be closed by a cover 45.

The insulating housing 41 also has guide channels 46, 47 into which the connecting lugs 26, 27 are inserted. The upper guide channel 46 has a curved guide surface 48 through which the terminal lug 26 is bent downwards when inserted into the guide channel 46 in FIG. 3, so that it engages with its latching element 34 through a latching opening 49 with the cover part 15 of the switch 12 came into contact. In this way, not only mechanical locking but also very good electrical contact is achieved.

In the exemplary embodiment according to FIG. 3, a latching part 51 is provided on the lower connecting lug 27 and comes into contact with the lower part 16 of the switch 12 when the insulating housing 41 is pushed on. In order to enable insertion of the thickened connecting lug 27 into the guide channel 47, the latter has an enlarged insertion opening 50.

The guide channels 46, 47 end in grooves 52, 53, in which the terminal lugs 26, 27 come to rest with their front ends 54, 55 when the insulating housing 41 has been completely pushed open. These grooves 52, 53 ensure that the electrical contact between the connecting lugs 26, 27 and the switch 12 is maintained even in the event of strong vibrations or other mechanical stresses.

Since the opening 44 extends perpendicular to the guide channels 46, 47, the inserted contact parts 24, 25 also ensure that the switch 12 is mechanically seated, so that the detent 43 could also be dispensed with if the switch 12 and the insulating housing 41 are to be stored separately .

In the exemplary embodiment according to FIG. 3, the holder 23 is arranged on a consumer 57, which has two connection elements 58, 59 for connection to an external circuit. While the connection element 59 is connected directly to the electrical load 57, the connection element 58 is in electrical connection with the connection lug 27. The second connection lug 26, on the other hand, is connected directly to the electrical load 57. Due to the selected arrangement, a switch 12 received between the connecting lugs 26, 27 is connected in series with the consumer 57 between the connecting elements 58, 59. It should also be mentioned that the connecting lugs 26, 27 face each other with their broad sides 61, 62.

Claims (10)

Insulating housing with an interior (11, 42) for receiving a mechanically and / or electrically protected switch (12) with a temperature-dependent switching mechanism, the switch (12) having two electrically conductive connection surfaces (13, 14) via which an electrical connection of the switch (12) on contact parts (24, 25) of a holder (23) or of an electrical consumer (57) to be protected,
characterized in that the insulating housing (10, 41) has at least one opening (18, 50) through which the contact parts (24, 25) come into direct contact with the two connection surfaces (13, 14) and the switch (12) pinch between them. Insulating housing according to claim 1, characterized in that it has an inner profile through which the inserted contact parts (24, 25) are pressed onto the connection surfaces (13, 14). Insulating housing according to claim 1 or 2, characterized in that it has at least one locking element (31, 49) via which it locks with an associated locking element (34) on one of the contact parts (24). Insulating housing according to one of claims 1 to 3, characterized in that it holds a received switch (12) captively. Insulating housing according to Claim 4, characterized in that it has latching means (21, 22, 43) which can be pushed over and which hold a received switch (12) captively. Insulating housing according to one of claims 1 to 5, characterized in that it has guide channels and / or grooves (37, 38; 46, 47) for the contact parts (24, 25). Insulating housing according to claim 6, characterized in that the guide channels and / or grooves (37, 38; 46, 47) have a guide surface (35, 36, 48) which is inclined in the longitudinal direction towards the interior (11, 42). Insulating housing according to claim 7, characterized in that the guide surface (48) is bent in the longitudinal direction. Insulating housing according to one of claims 1 to 8, characterized in that a further opening (44) is provided for inserting the switch (12) into the interior (42). Insulating housing according to claims 6 and 9, characterized in that the further opening (44) extends perpendicular to the guide channels and / or grooves (46, 47).

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