EP0746071B1 - Plug-in overvoltage protection device - Google Patents

Abstract

An array of diodes (12), two resistors (14) and a three-pole overvoltage diverter (16) are arranged on a circuit board (10) in a two-part housing (40). Plug-type zones (17) of the board are plugged into a row of contacts on a two-row connector moulding (42) with an earthing rail (44) into which the spring section (46) of an earth contact (19) is hooked. Between the earth contact and overvoltage diverter, two insulating sections (62, 64) of the thermoplastic protective element (18) are interposed. The element itself has two slightly concave sections and is spring-biased (36) to hold these in contact with the diverter.

Description

The present invention relates to a pluggable Surge protection for terminal strips of the Telecommunications technology.

A conventional surge protection is from the EP 0 471 167 and has a housing with one Connection contact for the wire to be protected and for one Earth discharge and one arranged in the housing Surge arrester on. A mechanically preloaded Thermal protection element is here by heating the Surge arrester can be triggered. With this previously known Surge protection is the thermal protection element Metallic slide that is conductive with a solder joint a sheet metal part is connected. Lies on the sheet metal part contacting the surge arrester, which by a internal gas discharge surges to earth dissipates and heats up. To be longer at one sustained surge arrester warming To avoid destruction of the protective plug, the thermal protection element, that is mechanically biased by a spring is triggered and separated by the heating of the solder joint the contact of the surge arrester with one Earth sheet on.

However, such a known surge protection is disadvantageous in that the thermal protection element over a Solder joint as well as a just contacting on the Overvoltage arrester thermally supported sheet metal part the surge arrester is connected. This is on the one hand, no optimal heat transfer guaranteed, because several heat transfer parts can be used. On the other hand the production is relatively complex and it must be Soldering points are provided that are not normally associated with the desired accuracy is reproducible.

Another pluggable surge protection is out of the EP 0 338 187 and consists of a one-piece, plastic housing open on one side, in which Surge arresters are arranged. With a permanent Ignition of the surge arrester melts through the resulting heat a so-called melting pill, whereby a springy shorting bar a connection with the common earth manufactures and short-circuits the surge arrester. Also here are several for the manufacture of the surge arrester Components required that are manufactured separately and need to be assembled.

A similar surge protector is from the EP 0 548 587 A1 and has a spacer, which is made of thermoplastic.

Finally, EP 0 312 729 A1 Thermal protection device known in an upward open chamber with a U-shaped bracket spring Preload is used. Next to this chamber is in another chamber a surge arrester, where both chambers through a thin partition from one thermoplastic are separated from each other. By the heating of the surge arrester at high Temperatures this partition becomes plastic, so that the Spring arms of the bow spring pierce the partition and so the Short-circuit the surge arrester.

It is therefore that of the present invention underlying problem (task), surge protection of the type mentioned to further develop that an inexpensive manufacture, easy assembly and a exact reproducibility of the trip are guaranteed.

This problem is solved by the features of 1. According to the invention, the thermal protection element, by heating the Surge arrester can be triggered, made of plastic thermoplastic properties. This can the thermal protection element directly by the heat of the Surge arresters are triggered without a Heat transfer via additional components such as Legs Soldering point, a melting pill or a partition is required is. At the same time, the thermal protection element can be removed Plastic with an extremely high reproducibility Manufacture so that no manufacturing or assembly-related Fluctuations in the triggering time can occur. By the solution according to the invention is considerable Cost savings due to the small number of used parts and easy assembly. Furthermore, the Thermal protection element on an insulation section, which itself in the initial state between the surge arrester and an earth contact. The thermal protection element is through heating of the surge arrester can be triggered and is mechanically biased so that when the Thermal protection element of the insulation section between the Surge arrester and the earth contact is moved out. As a result, the surge arrester and the earth contact in electrically contacting contact with each other, so that the surge arrester against earth is short-circuited and does not heat up further.

Advantageous embodiments of the invention are characterized by Subclaims marked.

According to a further embodiment of the invention, the thermal protection element have a section that on the Surge arrester is present. This will turn on advantageously achieved that only a limited Part of the thermal protection element, namely the subsection, is present at the surge arrester and from there Ignition correspondingly strong when overvoltage is present is heated.

According to an advantageous embodiment of the invention, a Tongue the thermal protection element against the mechanical Lock the bias, preferably in a recess in the Earth contact. This allows an exceptionally good one Achieve the thermal protection element, because the Trigger just removed the tongue from the recess must become. After heating the section, the melts on this molded tongue and thereby releases the lock, so that the thermal protection element is moved by the bias is and the contact between the surge arrester and releases an earth contact.

According to a further advantageous embodiment of the invention the thermal protection element can have a recess for material have that through the thermal contact with the Surge arrester melts. This makes it easy Way ensured that the thermal protection element reproducible triggers and not despite melting the Section jammed because the melted material itself can go into the recess. It is particularly advantageous here if the recess is in the area in the melted material during the melting process is pressed by the force of the mechanical preload.

According to further advantageous developments of the invention the surge arrester is a three-pole arrester and the Earth contact can be applied to the surge arrester be. This resilient application ensures that that when the thermal protection element is triggered reliably Contact between the earth and the surge arrester will be produced. In connection with the subordinate Fine protection from diode arrays and resistors are used in the further cable routing lying against inadmissible voltage influences protected. Here the fine protection component consists of three Suppressor diode chips on a ceramic substrate with the Advantage of higher pulse capacity, direct heat coupling of the three diode chips and small size, and two Resistances. A three-pole arrester is used for a pluggable surge protection for a to be protected Twin wire advantageous.

According to a further advantageous embodiment, the housing of the surge protection have a viewing window through that a part of the triggered thermal protection element is visible is. This makes it immediately apparent from the outside whether a thermal protection element has been triggered by the viewing window is looked at. This part is not triggered of the thermal protection element is not visible. Advantageously the corresponding part of the thermal protection element or also the entire thermal protection element in a striking Color.

According to further advantageous developments of the invention the connection contact for the wire to be protected on one printed circuit board designed like a plug contact, on the other electronic components such as resistors and Semiconductors are contacted as fine protection. By such Training is a very compact and easy to assemble Surge protection device created that none requires separate plug contacts because the circuit board as Plug contact is used. If the circuit board is loose can be inserted into the housing is a special one easy assembly ensured. Here, too Surge arrester must be contacted on the circuit board, whereby separate cabling can be omitted.

According to a particularly space-saving embodiment of the Invention can be a resistor and a semiconductor device, for example a diode array on the circuit board be arranged one above the other. This allows the pluggable surge protection particularly space-saving produce. A two-part design of the housing again facilitates assembly.

If the earth contact, when the thermal protection element is triggered contacted with the surge arrester, a spring-like section for engaging in has an earthing bar, are other components superfluous, which make this ground contact. Of the Surge protection according to the invention then only exists from the contacted with electrical components PCB, the thermoplastic thermal protection element, the Earth contact, the mechanical spring and the surrounding Casing. Such an embodiment has compared to that State of the art explained at the beginning much less Components.

According to a further advantageous embodiment, the Thermal protection element can be designed like a slide, wherein the tongue on a substantially U-shaped contour of the Thermal protection element is molded. Here, in advantageously the tongue and the contour to the Longitudinal extension of the thermal protection element in opposite directions run at an angle. This results in a special one good, resilient contact of the contour on the surge arrester, which increases functional reliability.

Since there are often several pluggable in a terminal block Surge protection devices are arranged, the Surge protection according to the invention according to a further Embodiment advantageously one from the outside accessible contour, into which a pulling hook or a Screwdriver or the like can be used to to remove the surge protector from the terminal block.

Fig. 1

eine perspektivische Ansicht des Überspannungsschutzes gemäß der Erfindung, jedoch ohne Gehäuse und Feder;

Fig. 2

das Thermo-Schutzelement gemäß der Erfindung;

Fig. 3

eine teilgeschnitte Querschnittsansicht des erfindungsgemäßen Überspannungsschutzes, der in eine Anschlußleiste eingesteckt ist, wobei das Thermo-Schutzelement im ausgelösten Zustand dargestellt ist;

Fig. 4

eine Teilansicht des in Fig. 3 dargestellten Überspannungsschutzes, wobei sich jedoch das Thermo-Schutzelement im nicht ausgelösten Zustand befindet.

The present invention is described below purely by way of example with reference to a preferred embodiment and the accompanying drawings. Show it:

Fig. 1

a perspective view of the surge protector according to the invention, but without the housing and spring;

Fig. 2

the thermal protection element according to the invention;

Fig. 3

a partially sectioned cross-sectional view of the surge protector according to the invention, which is inserted into a terminal block, the thermal protection element being shown in the triggered state;

Fig. 4

a partial view of the surge protector shown in Fig. 3, but the thermal protection element is in the non-triggered state.

The surge protection shown in Fig. 1 for Terminal strips of telecommunications technology is on one Printed circuit board 10, on which a diode array 12 and two resistors 14 are soldered, the resistors 14 above the diode array 12 or a hybrid module consisting of Diodes and resistors as an SMD component, are arranged to Save space. A three-pole surge arrester 16 is also on the basically elongated training PCB contacted. The circuit board 10 has on her lower end two parallel, plug-in trained Areas 17 on.

A thermal protection element 18 and an earth contact 19 are in Fig. 1 also shown and cause grounding prolonged heating of the surge arrester 16 in pluggable surge protection and the following connected components of the telecommunications system.

1 also shows, the circuit board 10 is with brackets 74 provided that the middle ground connection of the Contact surge arrester 16 with spring contact.

The thermal protection element 18 shown in FIG. 2 exists made of plastic with thermoplastic properties and is in formed essentially slide-like. In his lower The thermal protection element 18 has two crowned areas molded areas 20 and 21, which is a partial plant of the thermal protection element 18 on the cylindrical Allow surge arrester 16. Between the crowned Areas 20, 21 have a rectangular opening 22 formed in which projects a U-shaped contour 24, the two Leg of the U-shaped contour 24 to the lower region 20 adjoin. At the base of the U-shaped contour 24, the one Forms partial area 28, a tongue 26 is in one piece molded.

As can be seen in Fig. 2, the tongue 26 and the Contour 24 to the longitudinal extent of the thermal protection element arranged angled in opposite directions, the contour from the Opening 22 protrudes. As a result, the partial area 28, namely the base of the contour 24, close to that Surge arresters 16 are present (see FIG. 4). At a Melting the portion 28 can the melting material get into the recess 30 which through the contour 24 in whose interior is formed.

In the upper area of the thermal protection element shown in FIG. 2 18 is another rectangular opening 32 formed in the two guide pins 33 and 34 in Longitudinal direction of the thermal protection element are arranged. Here, the longer pin 33 and the shorter pin serve 34 to fix a spring 36 (see. Fig. 3). The upper Area 38 of the thermal protection element shown in FIG. 2 is shown rasterized, is made in red color, so that it can easily be seen through a window 66 in one Housing 40 (see FIG. 3) can be recognized after the Thermal protection element has been triggered.

3 shows the circuit board 10 on which the Diode array 12, the resistors 14 and the Surge arrester 16 are contacted in a two-part housing 40 inserted, only in Fig. 3 a housing half is shown. The in Fig. 1st shown plug-contact-like extensions 17 of the circuit board 10 are not in a row of contacts Two-row terminal block 42 (shown in FIG. 3) inserted, the terminal block being inserted Earth rail 44 has a C-shaped cross section is formed and openings 45 in this area has, in each case a spring-like shaped section 46 of the earth contact 19 can be inserted.

The earth contact 19, which can also be clearly seen in FIG. 1, is made in one piece from metal and connects the spring-shaped section 46 with two others molded spring contacts 48 and 50, which are triggered in the State of the thermal protection element 18 on the two Wire contacts 60, 61 of the surge arrester 16 are present (Fig. 3). The two contacts 48 and 50 are U-shaped U-shaped section 52 is formed, at the base of the Section a recess 54 is formed in those in the non-triggered state of the thermal protection element 18 engages the tongue 26 of the thermal protection element 18 (cf. Fig. 4).

3 shows, both the circuit board 10 and the earth contact 19 is mounted in the housing 40, one pin-like housing contour 56 in the U-shaped section 52 of the earth contact 19 engages around this on the housing to store.

The thermal protection element 18 is, as shown in Fig. 3, biased by the spring 36 which over the short pin 34th and the long pin 33 is inserted. To accommodate the The spring 36 bears against a housing projection 58 and thereby exercises a vertically upward in Fig. 3 Force on the thermal protection element 18.

Fig. 4 shows in detail the interaction of the earth contact 19, the thermal protection element 18 and the Surge arrester 16 in the non-triggered state. How can be clearly seen, presses that not shown in Fig. 4 Spring 36 the thermal protection element 18 in FIG. 4 upwards, however, the tongue 26 in the recess 54 of the Earth contact 19 engages so that the relative position between earth contact 19 and thermal protection element 18 which in Fig. 4 is shown. In this position the Section 28 (see also Fig. 2) of the U-shaped Contour 24 resiliently on the surge arrester 16 and is by the angled formation of the contour 24 against this biased. An electrical contact between the Wire contacts 60 and 61 of the surge arrester 16 with the Spring contacts 48 and 50 of the earth contact 19 is, however avoided by insulation sections 62, 64 by the Material section of areas 21 and 20 (see FIG. 2) are formed.

The mode of operation of the invention is described below Surge protection described.

The surge protector is usually in one Terminal block 42 of the telecommunications technology inserted, wherein the plug-in regions 17 of the Printed circuit board 10 in corresponding plug contacts Terminal block are there and only one of two Cover rows of contacts. The spring-like region 46 of the Earth contact 19 is in the opening 45 of the earth rail 44 inserted.

In the untripped state of the surge protection, that is shown in Fig. 4 become smaller Overvoltages between two wires by the on the Printed circuit board 10 electronic components intercepted. When larger overvoltages occur The surge arrester 16 ignites between the two wires and warms up. Unless lasting longer Surges occur, the heats up Surge arrester 16 very strong, so that at this adjacent section 28 made of thermoplastic material begins to melt. At this point the thermal protection element by the action of the spring 36 in Fig. 4 prestressed above, but is in this prestressed position held by the tongue 26 which in the recess 54 of the Earth contact 19 engages.

After section 28 begins to melt, this can melted material in the recess 30 of the thermal protection element 18 arrive because during the melting process a pressure is constantly exerted by the spring 36. The state shown in FIG. 3 then arises a, d. H. the tongue 26 is released from the recess 54 of the Thermal protection element 18 and thereby gives the thermal protection element 18 free by the action of the spring 36 in Fig. 3 pressed up to a housing-fixed stop becomes. As a result, the insulation sections 62 and 64 moved upwards, so that the spring contacts 48 and 50 of the Earth contact 19, the wire contacts 60 and 61 of the Touch surge arrester 16 making contact under pressure, whereby the surge arrester 16 against earth is short-circuited and does not heat up further. That I the area 38 (FIG. 2) of the thermal protection element now in the 3 is located, this can by the Viewing window 66 can be easily recognized from the outside.

Then also to the surge protection according to the invention easy to remove from a terminal block, if several such devices are placed next to each other, is the housing 40 with a graspable from the outside Provided contour 68, in which a pulling hook 70 one Wiring instrument can be used.

The split housing 40 is provided with corresponding detents 72 provided so that only the component shown in Fig. 1 be inserted into the housing 40 together with the spring 36 must, whereupon this can then be put together.

In the following claims, the Reference numbers for better understanding and are intended to Do not limit the scope of protection.

Claims (18)

1. Plug-in type overvoltage protection for terminal strips (42) in telecommunications engineering having

   a housing (40),

   a connecting contact (17, 46) for each conductor to be protected and for an earth connection,

   an overvoltage protector (16) arranged in the housing (40), and

   a thermal protection element (18) made of a plastic having thermoplastic properties

   which has an insulating section (62, 64) located in the initial position between the overvoltage protector (16) and an earth contact (19),

   wherein the thermal protection element (18) can be released by heating of the overvoltage protector (16) and mechanically pretensioned in such a way

   that when the thermal protection element (18) is released the insulating section (62, 64) between the overvoltage protector (16) and the earth contact (19) is moved out so that these make contact.
2. Device according to Claim 1, characterised in that the thermal protection element (18) has a partial section (28) which rests against the overvoltage protector (16).
3. Device according to Claim 2, characterised in that a tongue (26) of the thermal protection element (18) locks the latter against the pretensioning, preferably in a recess (54) of the earth contact.
4. Device according to Claim 2 and 3, characterised in that fusion of the partial section (28) due to heating of the overvoltage protector (16) brings about unlocking of the thermal protection element (18).
5. Device according to one of the preceding claims, characterised in that the thermal protection element (18) has a recess (30) for material (28) melting due to thermal contact with the overvoltage protector (16).
6. Device according to one of the preceding claims, characterised in that the mechanical pretensioning ensues by means of a spring (36) which pretensions the thermal protection element (18) against a housing contour (58).
7. Device according to one of the preceding claims, characterised in that the overvoltage protector is a three-pole protector (16).
8. Device according to one of the preceding claims, characterised in that the earth contact (19) can be placed in sprung manner against the conductor contact (60, 61) of the overvoltage protector (16).
9. Device according to one of the preceding claims, characterised in that the earth contact (19) rests in sprung manner against the earthing connection (74) of the overvoltage protector (16).
10. Device according to one of the preceding claims, characterised in that the housing (40) has a viewing window (66) through which a part (38) of the released thermal protection element (18) is visible.
11. Device according to one of the preceding claims, characterised in that the connecting contact (17) for the conductor to be protected is provided from a printed circuit board (10) which is constructed in the manner of a plug contact and on which contact is made with further electronic components such as resistors (14) and semiconductors (12) as fine protection.
12. Device according to Claim 11, characterised in that the printed circuit board (10) is inserted loosely into the preferably two-part housing (40).
13. Device according to Claim 11 or 12, characterised in that the overvoltage protector (16) makes contact on the printed circuit board (10).
14. Device according to Claim 11, 12 or 13, characterised in that a resistor (14) and a semiconductor component (12) or a hybrid module are arranged one above the other on the printed circuit board (10).
15. Device according to one of Claims 1 to 14, characterised in that the earth contact (19) has a section (46) in the shape of a spring for engagement in openings (45) of an earthing bus (46).
16. Device according to one of Claims 3 to 15, characterised in that the thermal protection element (18) is constructed in the manner of a slide and the tongue (26) is formed on an essentially U-shaped contour (24).
17. Device according to Claim 16, characterised in that the tongue (26) and the contour (24) extend in angled manner in the opposite direction with respect to the longitudinal extension of the thermal protection element (18).
18. Device according to one of the preceding claims, characterised in that the housing (40) has a contour (68) which can be engaged rearwardly from the outside and into which a pulling hook (70) can be inserted for detaching the overvoltage protection from a terminal strip (42).

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