Electric contact assembly

A contact assembly having a spring contact strip and a contact element, in particular, a subrack front panel. The spring contact strip has a contact limb that is bent over, with an end that can be freely pivoted. To improve the mechanical stability of the spring contact strip, the inventive contact limb extends an entire length of the spring contact strip.

The invention relates to a contact assembly with a contact spring strip and a contact element, in particular of a front plate of a component support, wherein the contact spring strip has a contact leg, which is bent off and whose end can be swiveled out.

Such a contact assembly is known from DE 198 46 627 C1. Here a contact spring strip is used, from which a contact spring leaf and a clamping leaf extend alternatingly in rows. The contact spring leaves are separated from the clamping leaves. In this way the contact spring leaf can freely swivel out at its free end. But the clamping leaf is snapped into a detent strip of a front plate and is fixedly maintained thereon. The contact spring strip is in an electrically conducting connection with the front plate. Adjoining lined-up components can be put in electrically conducting contact in the area of their front plates by means of the contact spring leaves. In the course of the structural layout it must be taken into consideration that the contact spring strips can be subjected to mechanical stresses. This is the case in particular where projections, for example remnants of solder or soldering pins, of adjoining components become snagged at the contact spring strips during assembly or disassembly of the components in a component support.

A contact spring strip is disclosed in DE 195 44 835 C1, which has a continuous detent shoulder extending in the longitudinal profile direction. A plurality of contact springs is bent away from this. They are arranged next to each other and are spaced apart from each other by means of separating slits. A relatively large outlay for profiling and punching is needed in connection with these contact spring strips.

It is the object of the invention to produce a contact arrangement of the type mentioned at the outset, wherein the contact spring strip is of simple construction and is insensitive to mechanical effects.

This object is attained in that the contact leg extends continuously in the longitudinal direction of the contact spring strip.

In contrast to contact spring strips which were commonly used up to now, a continuous contact leg is used in accordance with the invention. With this, the danger of damage by mechanical forces is clearly reduced.

In particular, the contact leg prevents protruding elements of adjacent components from becoming snagged. Moreover, because of the use of continuous contact legs it is possible to realize a substantially simplified construction along with a reduced punching and profiling outlay.

It is provided in accordance with a preferred embodiment variation of the invention that the contact spring strip has a continuous contact line or contact face on its contact leg, which extends in the longitudinal direction of the contact spring. This assures dependable shielding, even under the most diverse EMC requirements.

For improving the contactability, it can be provided that spaced-apart contact elements are arranged on the contact line or contact face, which protrude past the contact line or contact face and which can be provided with contact edges or contact tips. When mounting the front plate, the contact elements can be supported on or dig into the surface of an adjoining component with which contact is to be made.

In a preferred manner, the contact elements have been punched out of the contact leg and are bent away from it. In this case the punched edges then constitute the contact edges or contact tips.

It is also conceivable for the contact elements to be embodied as embossed nubs. These can also be embossed in such a way that tear edges are created in the course of the embossing process. These are then used for improving the contact.

In a preferred embodiment the contact elements are either spring-elastically resilient in defined areas, or they are connected to the contact spring strip via spring areas. A tolerance compensation can be realized by means of this

In order to always assure a sufficiently adequate EMC protection it is provided in accordance with a possible variation of the invention that the contact elements are arranged with identical spacing from each other, wherein the spacing distance is determined by EMC considerations. Since the contact elements lie next to each other at predetermined distances, electromagnetic waves are prevented from passing through the contact zone in an impermissible manner.

A stable connection between the contact spring strip and the detent strip results in particular if it is provided that the contact leg is bent away from a bar of the contact spring strip, and that catches are punched out in the transition area between the bar and the contact leg and are bent off in the direction toward the detent strip of the front plate. Due to the fact that the bar at the contact strip can be embodied to be continuous, an optimized positioning and dimensioning of the detent tongues is possible when laying out the contact spring strip.

A contact arrangement in accordance with the invention can also be such that a connecting section follows the contact leg and is connected with a support element, which is snapped together with the detent strip. Accordingly, the contact spring strip is constituted of two parts.

In this case the support element can be embodied to be substantially U-shaped and can be clampingly maintained by means of a bar and a holding strip on two oppositely located sides of the detent strip. The bar is connected with the holding strip by means of a cap section. Here, the connecting section of the contact leg is connected with the support element in the area of the cap section.

It can also be alternatively provided for the contact spring strip to have a holding strip, which is connected via a cap section with a bar, that the holding strip, the bar and the cap section enclose, at least partially, a head section at the end of the detent strip, and that the contact leg is angled off the bar in the direction facing away from the detent strip. A single-piece closed element, which is particularly simply designed is the result of this embodiment. It is insensitive to mechanical stresses in particular.

A component support front plate (called front plate30for short in what follows) is represented inFIG. 1. The front plate30has a plate-like section at the front, which is adjoined at right angles by a detent strip31. On its free end, the detent strip31has a head area33. On its exterior, the head area33is provided with a continuous groove32. The front plate30furthermore has a groove34on the outside in the base area of the detent strip31. The front plate30is embodied in a single piece as a profiled extruded section. A contact spring strip10can be placed on the detent strip31and the front plate30. The design of the contact spring strip10can be seen in greater detail inFIGS. 2 and 3. As illustrated in these representations, the contact spring strip10has a holding strip13on its rear, from whose free end an angled-off element11is bent off by means of a transition section12. On the side facing away from the angled-off element11, the holding strip13makes a transition into a U-shaped cap section14. A bar15, which can be placed parallel with or slightly angled away from the holding strip13, adjoins the cap section14. On its end facing away from the cap section14, the bar15makes a transition into a contact leg16. The contact leg16is essentially put together from two partial legs, which are arranged in a V-shape in respect to each other. The contact leg16constitutes a contact face extending continuously in the direction of the contact spring strip10. On its free end, the contact leg16terminates in an inwardly bent end section17. Catches19are punched out of the bar15and bent off in the direction toward the holding strip13. The catches19are spaced evenly apart in respect to each other. The catches19themselves are bent off in the transition area between the bar15and the contact leg16.

AsFIG. 2shows, contact element18are arranged, distributed over the contact face. In the present case the contact elements18are embodied as embossed elements, which have been pressed out of the contact face of the contact leg18and are bent out in the direction facing away from the holding strip13. The embossed elements can also be provided with contact edges or contact tips.

It becomes clear fromFIG. 3, that the contact spring strip10can be provided with a partition slit20at regular intervals. In this case the partition slit20separates the angled-off element11, the transition section12and the cap section14. The cap section14can be cut through completely or partially here. In the present exemplary embodiment the cap section14is only partially cut through. The contact spring strip is provided with an increased stiffness by this.

As can be seen inFIG. 1, the contact spring strip10can be simply mounted on the detent strip30. To this end, the contact spring strip10is placed with its transition section12on an inclined portion of the head area33of the front plate30. The angled-off element11is then deflected at this inclined portion. It can the be displaced along an inner surface of the detent strip31until the angled-off element11snaps in behind a formed edge of the detent strip31. In this mounting position the catches19also snap into the detent groove32of the detent strip31. In the mounted position, the contact leg16is freely swivelable at its end, so that it can be deflected into the groove34with the end section17.

Modified variations of contact spring strips10are described inFIGS. 4 and 5. The front plates30are essentially of the same construction as the variation of a front plate30represented inFIG. 1. The contact spring strip10in accordance withFIG. 4is of two-part construction. Accordingly, a bevel16.1is bent off the contact leg16, which in turn makes a transition into a bent-off connecting section16.2. The connecting section16.2lies flat against the inside of a holding strip13of a support element. The connecting section16.2is attached to the support element in the area of the holding strip13. In the head area33of the detent strip31the bevel16.1rests on the cap section14of the support element.

Protrusions21, which are supported on the detent strip31, are provided for improving the holding of the contact spring strip10. The protrusions21can be embodied as holding claws, which dig into the surface of the detent strip31and improve the contact in this way.

In the embodiment variation represented inFIG. 5, a connecting section16.2has been bent off the contact leg16. It rests on the cap section14of the support element and is connected with it. Otherwise the design of the contact spring strip10corresponds to the form represented inFIG. 4.