Surge protection plug and ground bus

The invention relates to a surge protection plug (1) for connector or distributor modules in telecommunications and data fields, comprising a housing and a printed circuit board, wherein at least one surge protection element is disposed on the printed circuit board and the printed circuit board comprises a plug-in region on which electric contact pads are disposed that are electrically connected to the surge protection element, wherein the surge protection element is at least connected to a ground line, wherein the housing (3) is designed in an at least partially electrically conductive manner, wherein the housing (3) is electrically connected at an electrically conductive point to the ground line on the printed circuit board (4) or to a ground connection (23) of the surge protection element (19). The invention further related to a ground bus (2) suitable for this purpose.

RELATED APPLICATIONS

This application is a National Stage Application of PCT/EP2008/008633, filed 13 Oct. 2008, which claims benefit of Serial No. 10 2007 055 259.0, filed 20 Nov. 2007 in Germany and which applications are incorporated herein by reference. To the extent appropriate, a claim of priority is made to each of the above disclosed applications.

TECHNICAL FIELD

The invention relates to an overvoltage protection plug for connection or distribution board modules in telecommunications and data technology and to a grounding rail suitable for this purpose.

BACKGROUND

Such overvoltage protection plugs are known, for example, from DE 100 29 650 A1 and comprise, for example, a housing and a printed circuit board, at least one overvoltage protection element being arranged on the printed circuit board, and the printed circuit board having a plug-in region, on which electrical contact pads are arranged, which are electrically connected to the overvoltage protection element, the overvoltage protection element being connected to at least one ground line. In this case, a metal web is arranged on the printed circuit board, which metal web is electrically connected to the ground line and makes electrical contact with a grounding rail when the overvoltage protection plug is plugged.

SUMMARY

The invention is based on the technical problem of providing an overvoltage protection plug which is simpler in terms of design and of providing a grounding rail suitable for this purpose.

For this purpose, the overvoltage protection plug comprises a housing and a printed circuit board, at least one overvoltage protection element on the printed circuit board having a plug-in region, on which electrical contact pads are arranged, which are electrically connected to the overvoltage protection element, the overvoltage protection element being connected to at least one ground line, the housing being designed to be at least partially electrically conductive, and the housing being electrically connected to the ground line on the printed circuit board or a ground connection of the overvoltage protection element at an electrically conductive point. As a result, the separate contact element on the printed circuit board is no longer required and the housing can be connected to the printed circuit board in a similar manner to an SMD element. If the housing is directly electrically connected to the ground connection of the overvoltage protection element, this connection represents the ground line, so that separate ground lines on the printed circuit board are no longer required.

In a preferred embodiment, the housing is designed to have at least one contact web for making contact with a fork contact of a grounding rail.

Preferably, the contact web is arranged on the inner side of an upper part of the housing.

In a further preferred embodiment, guide elements, in which parts of a grounding rail can be guided, are arranged on the inner sides of side parts of the housing.

In a further preferred embodiment, the housing is completely electrically conductive. This has the advantage of simple manufacture. On the other hand, an embodiment may also be advantageous where part of the housing is electrically nonconductive, so that a user can grip an electrically nonconductive region when handling the plug.

In a further preferred embodiment, the housing is designed to be integral.

In a further preferred embodiment, the housing is made from metal, a metal alloy or a metallized plastic. As the alloy, the housing is preferably formed using zinc diecasting. In embodiments where the housing is only partially electrically conductive, it is preferably manufactured from a two-component plastic, in this case the electrically conductive parts being electroplated.

In a further preferred embodiment, in each case two contact pads are arranged on the upper and the lower side of the printed circuit board in the plug-in region of the printed circuit board. In embodiments only with surge arrestors, in this case the contact pads on the upper side are plated through to the contact pads on the lower side. In embodiments with coordinated protection, the contact pads, on the other hand, are not plated through since the PTC thermistors lie electrically therebetween.

In a further preferred embodiment, the printed circuit board is in the form of a multilayer printed circuit board, the conductor tracks being guided from the overvoltage protection element to the contact pads in a central plane of the multilayer printed circuit board. As a result, the risk of undesired short circuits between the conductor tracks and the housing is reduced.

In a further preferred embodiment, the housing has at least one latching element, via which the overvoltage protection plug can be latched on a housing of a connection or distribution board module.

In a further preferred embodiment, at least two overvoltage protection elements, which are applied to the printed circuit board as a prefabricated unit, are arranged on the printed circuit board. As a result, the overvoltage protection elements have greater mechanical stability, so that unintentional sliding of components against the housing during manufacture and therefore the risk of short circuits is reduced.

In a further preferred embodiment, the housing is soldered to the ground line on the printed circuit board.

In a further preferred embodiment, the housing is adhesively bonded to the ground line on the printed circuit board with electrically conductive adhesive bonds. This type of connection can preferably be used for UESS circuits with low requirements for current-carrying capacity.

DETAILED DESCRIPTION

FIGS. 1 and 2illustrate, perspectively, an overvoltage protection plug1, the latter as yet not having been plugged onto a grounding rail2. The overvoltage protection plug1comprises a housing3and a printed circuit board4. The housing3comprises an upper part5, two side parts6and two end sides7,8. The lower side is open and is closed by the printed circuit board4(seeFIG. 3or4). The grounding rail2comprises a base rail, which is generally designed to be planar. Sprung limbs10,11are arranged at a lower edge of the base rail, the limbs first extending away from the lower edge of the base rail virtually at right angles and then being bent back towards the lower edge again, the bent-back limb parts running towards one another and forming a fork contact12. For this purpose, the limbs10,11each have a rounded-off contact region pointing towards the other limb. Then fixing means and ground contacts are preferably arranged at the ends of the base rail which are not illustrated, via which fixing means and ground contacts the grounding rail can be fixed on a distribution strip, an electrical connection to a mounting frame being provided via the grounding contact. On the front end side7, the housing3has two slots9, through which in each case one sprung limb10,11of the grounding rail2can enter. In each case one guide element13, which is located above the slots9, is arranged on the inner side of the side parts6. In this case, the guide elements13are preferably connected both to the side part6and to the front end side7. A contact web14, which is arranged on the inner side of the upper part5and is preferably also connected to the end side7, is arranged between the two guide elements13. Furthermore, a latching element15, which extends in the direction of a plug-in region16of the printed circuit board4, is arranged on the end side7. The side parts6extend over the end side7, further latching elements18being arranged on the side parts6. The housing3is designed to be completely electrically conductive and is produced, for example, using zinc diecasting. Overvoltage protection elements, namely a surge arrestor19and two PTC thermistors20, are arranged on the printed circuit board4. The surge arrestor19has a ground connection23, which is connected to at least one ground line on the printed circuit board4. The ground line is guided to the side parts6, where it is connected to the housing3via two soldered joints21. Two contact pads22are arranged on the printed circuit board4in the plug-in region16. Likewise, two contact pads are arranged on the lower side of the printed circuit board4. The contact pads22are in this case connected to the linear contacts of the overvoltage protection elements19,20via conductor tracks.

If the overvoltage protection plug1is now plugged into a connection or distribution board module with the grounding rail2, the two limbs10,11pass through the slots9, contact being made with the contact web14by means of the fork contact12. A ground connection via the housing3is thus produced. The overvoltage protection plug1is mechanically latched on the housing of the connection or distribution board module via the latching tab17or the latching element18.

LIST OF REFERENCE SYMBOLS