The invention relates to a press-fit contact produced as a turned part for establishing an electrical connection, for example in a plated-through hole of a printed circuit board, for plug-in connections or else as an attachment point for a soldered connection.
In the case of conventional press-fit contacts of said type, as even a contact pressure as possible or an even contact-making over the entire region of contact between the pressed-in contact and the surrounding contact medium is desired. Owing to production inaccuracies and/or tolerances or else on account of not quite axially aligned pressing-in of the contact, differing bearing pressures occur in the contact zone and consequently partially differing current loading or wearing in the connection region between the contact pin and the contact hole.
EP-A-0 236 186 discloses a press-fit pin, wherein the press-in zone is designed cylindrically hollow at the inside and is provided with two axially parallel longitudinal slits. This pin comprises a contact section for engagement with a hole having a conductive surface. The contact section comprises a pair of elongated beams extending in the longitudinal direction of the pin, each beam having a generally C- shaped cross section. An electrical and mechanical contact between the pin and the hole takes place only at end portions and at central portions of the "C", resulting in rather high local contact pressure.
The invention is based on the object of improving a press-fit contact of said type in such a way that an even bearing pressure and even contact-making are ensured over the entire contact zone.
In the case of a press-fit contact made as a turn part, the invention comprises that the press-in zone is shaped in the form of a barrel in its outer contour. the greatest diameter region lying in the region of the highest bending moment.
It is advantageous to design the lower, free edge of the press-fit contact, which edge is to be inserted into the contact hole, in the form of a solid ring with peripheral edge bevel.
An embodiment of the invention is explained below with reference to the drawing, in which,
The press-fit contact 1 may be provided in its upper region with a peripheral cross-sectional widening 3 with supporting shoulders 2 and at the upper end with an attachment stub 4, for example for producing a soldered contact, a contact pin or a contact spring. In the region of the press-in zone 10, the press-fit contact 1 is, according to the invention, shaped in the form of a barrel in its outer contour 8 and turned or drilled out hollow-cylindrically in the inner region 9. The barrel-formed contour is interrupted by a plurality of, for example four, axially parallel longitudinal slits 6.
However, the longitudinal slits 6 preferably do not run over the entire length of the press-in zone 10, but only over a subregion, in such a way that an annular insertion edge 5, which is provided on the outside with an insertion bevel 11, remains at the lower, free end, the insertion region.
Due to the barrel-formed shaping of the press-in zone 6, on the one hand pressing-in is made easier in conjunction with the insertion bevel 11. On the other hand, the contact region 10 is loaded approximately evenly over its entire length in all cross-sectional regions, the greatest diameter region lying in the region of the highest bending moment.
In accordance with the definition of the object, with the invention the pressing-in of such press-fit contacts is made easier and a substantially even contact-making over the entire press-in zone is achieved.