Since a large number of connector pins are provided in a plug-in connector, a compact design of these connector sockets is very important. The outer cages of the connector sockets typically have transverse dimensions of 2 x 2 mm.

Since a plugging operation involves inserting a large number of connectors into corresponding sockets, the inserting force to be expended must not be too great and at the same time satisfactory electrical contact and adequately high retaining forces must be ensured. EP-255 245 A1 describes a socket contact of the type specified in the precharacterizing clause of Claim 1. In this case, the insertion region is designed as a box-shaped sheet-metal frame with four contact tongues, which are fastened on both sides to frame parts and have contact points formed in the vicinity of the insertion region. The contact points are at the same height and the tongues are all of the same design, with the result that the entire spring force of all four resilient tongues acts simultaneously during the insertion operation, with the result that, if up to 50 connector pins of a plug-in connector are inserted simultaneously into a corresponding connector socket, the insertion force is very high during a short time interval.

EP-353 330 describes a socket contact for electrical connectors in which contact elements comprise resilient elements, with a free head end, the contact elements being arranged lying one behind the other in the direction of insertion. In this way, the insertion force is distributed over time and is

consequently spread evenly throughout the insertion operation. The mutually opposite contact points of the resilient elements are not the same. The free end of a long resilient tongue and a contact element bent inwards from a short cutout respectively lie opposite one another. A relatively rigid guidance of the connector to be inserted consequently takes place at these relatively inflexible protrusions, with the result that skewed insertion of the connector pins ( ????) sic. Furthermore, the spring deflection of the resilient tongues is limited by little space being provided for free movement within the reinforcing cage.

The present invention is based on the object of improving a socket contact of the type mentioned at the beginning in such a way that optimum electrical contacting and high retaining forces are realized with low insertion forces distributed throughout the entire insertion operation.

This object is achieved as claimed. Preferred embodiments of the invention are characterized in the subclaims.

According to the invention, at the insertion end of the box-shaped female connector the"box"is divided into two, with two sides respectively joined together via an edge forming a unit. That is to say, resilient elements whose spring deflections form an angle of 90° with respect to one another are fastened on one part of the"frame"and the same arrangement is to be found diametrically opposite. Consequently, the flexibility of the contact elements is not limited only to their own spring deflection, but instead the box frame can partially resonant in the outer cage. As a result, an insertion force that is distributed more evenly throughout the insertion operation than in the case of the prior art is accomplished.

The invention is explained in more detail below on the basis of the description of an exemplary embodiment with reference to the drawings, in which:

Figures la and b show two perspective views of the socket contact according to the invention with the outer cage pulled off, and Figure 2 shows three perspective views of the socket contact according to the invention with the outer cage fitted.

Figure la perspectively shows on the right the socket contact 1 and on the left the reinforcing cage 2, which is fitted over the box-shaped sheet-metal frame 3 of the socket contact, in order to reinforce the latter. Behind the sheet-metal frame 3 there is the connection part 4 for a cable connection and for crimping the cable. The box-shaped sheet-metal frame 3 has four contact elements 5,6, first contact elements 5 connecting a front frame part 7 to a rear frame part 8. Second contact elements 6 extend from the front frame part 7 and have a free head end 9, which extends in the direction of the rear frame part 8.

The front frame part 7 is in two parts, with two sides respectively joined together via an edge and the other side ends not being joined together. As a result, two neighbouring resilient elements 5 and 6 respectively are fastened on a front frame part and the two frame parts lie diametrically opposite one another.

Furthermore, the arrangement of the contact elements is symmetrical to the extent that the first resilient elements 5 and the second resilient elements 6 likewise lie opposite one another.

The first resilient elements are bent sharply inwards just behind the front frame part, in order to form a resting point there with the connector pin to be inserted, whereas in the case of the second contact elements the contact with the connector does not take place until later during the insertion operation, via the head ends of the second resilient elements. The reinforcing cage 2 is slipped over the sheet-metal arms 3, and fastened by means of clips 10 to the sheet-metal frame 3 in a recess 11 provided for this purpose.

Figure 2 shows the socket contact 1 provided with the reinforcing cage 2 in several perspective views. Figure 2a shows the fastening clips 10 and Figure 2b clearly shows that the reinforcing cage has, on its end, inwardly curved sheet-metal lugs 12, which guide the connector pin. The reinforcing cage 2 is produced from stainless steel, whereas the rest of the sheet-metal frame is produced from a copper wrought alloy. As can be seen in Figure 2b, the reinforcing cage 2 has on its upper side a rib 13, which serves for coding during insertion into a connector housing.

Figure 2c shows that on this coding rib 13 fastening clips are provided, by which the reinforcing cage 2 folded from a metal sheet is fastened in itself.

The reinforcing cage is, furthermore, dimensioned in such a way that the sides of the front parts of the sheet-metal frame 7 on which the second contact elements are provided cannot move outwards, whereas the first contact elements 5 can move somewhat in the reinforcing frame 2 together with the corresponding sides to which they are joined on the front sheet-metal frame 7. This provides the overall socket arrangement with some flexibility, which leads to evening out of the insertion force to be expended.

The exemplary embodiment described above is not to be understood in a restrictive sense. The invention relates to all socket contacts covered by the wording of the claims.