Patent Application
20070218733
The difficulty in implementing efficient socket contacts (electrical plug connectors) is, in response to overall space for the plug connections that is getting smaller all the time, to allow to be effective sufficiently great contact normal forces at the contact places between the contact lamellae of the socket contacts and the contact pins (contact blades) of the mating connectors. These contact normal forces are to be designated as being sufficient if they ensure an electrically conductive contact, even in the case of extraneous layers on the metallic surfaces of the contact partners, that is, when such extraneous layers are not pushed through with certainty.
a shows a known electrical plug connector (socket contact) 20a into which a contact pin is plugged. In this plug contact 20a, a current-conducting contact element 21 having a resilient contact lamella 22 is made of a contact material which has a sufficiently great relaxation stability, even at high working temperatures, to counter an inadmissible decrease in the contact normal force over long periods of use. These relaxation-stable and sufficiently conductive contact materials are, however, comparatively expensive.
Apart from that, other electrical plug connectors (socket contact) are known in which, in addition, force support springs (leaf springs), made of materials that are the same or materials that are not the same, assist, by mechanical coupling with the contact lamellae, in achieving the desired contact normal forces at the contact points and in ensuring them in a durable manner.
Because of the plug connectors according to the present invention, it is possible for the first time, without limiting the technical function of the additional leaf spring, to do without costly steel material of an enclosing steel sleeve, which is only used for fixing and supporting the leaf spring. Beyond that, because of the specific material utilization without having to consider the design of the steel sleeve, constructive freedoms come about for the contour and position of the leaf spring, which are able to be used for an optimization of the spring properties. Using this material-saving force-supporting spring for electrical socket contacts, a uniformly high contact normal force is achieved and maintained of the contact lamella situated below it with respect to the contact pin of the opposite side.
The leaf spring is fitted into the contact element of the plug connector in such a way that only specifically the contact lamella is supported and, because of that, a material-intensive jacketing of the contact element, using a steel sleeve, can be omitted. To do this, preferably the leaf spring is produced, in a material-saving manner, from a narrow steel strip, and during the manufacturing process of the contact element it is positioned on the latter's blank, for instance, mechanically, and fixed. In the subsequent working steps of the stamping and bending process, the blank, along with the fixed leaf spring, is bent to the finished state to form the contact element. Because of the bending sequence, the leaf spring comes to lie behind the contact lamella. In the final arrangement, the contact lamella acquires the task of contacting and conducting current, whereas the narrow leaf spring acts in a force-supporting manner. Because of the nesting of the contact element, the fixing and support of the leaf spring are ensured. In principle, it is also possible to position and fasten the leaf spring only after the complete bending to a finished state of the contact element.
a and 1b show the electrical plug connector according to the present invention in the initial state ready for insertion (
a-2c show various prior known electrical plug connectors not having a leaf spring (
The electrical plug connector 1 shown in
Plug accommodation 5 is formed laterally by three outer walls 8a-8c of contact element 2 and a contact lamella 9, whose free end 10 is directed counter to direction of insertion 7 of contact pin 6. The other, fixed end of contact lamella 9 is formed by an intermediate wall 11 of contact element 2, which runs parallel to outer wall 8d. Between this outer wall 8d and intermediate wall 11 there is situated a leaf spring 12 fastened to contact element 2, whose free end 13 is also directed counter to direction of insertion 7 of contact pin 6, and which acts upon contact lamella 9. Contact lamella 9 has an impressed contact crest 14, and outer wall 8a lying opposite contact lamella 9 has a pressed-out contact crest 15.
Leaf spring 12 is a narrow metal strip made of steel, which is, for instance, mechanically positioned and fixed to the sheet metal (contact blank) that is to be reshaped to form contact element 2. In the subsequent working steps of the stamping and bending process, the contact blank, along with fixed leaf spring 12, is bent to the finished state to form the contact element 2. Because of the bending sequence, leaf spring 12 gets to lie behind contact lamella 9, that is, between outer wall 8d and intermediate wall 11, and is also clamped between them. In plug connector 1, the contact lamella 9 acquires the task of contacting and conducting current, whereas arrow leaf spring 12 acts in a force-supporting manner. Because of the nesting of contact element 2, the fixing and support of leaf spring 12 are ensured.
In the initial state of plug connector 1, that is ready for insertion, shown in
| Number | Date | Country | Kind |
|---|---|---|---|
| 102006009075.6 | Feb 2006 | DE | national |
