FR2498824A1 - Three-part female contact for electrical connector - has inner sleeve provided with wire receiving part made from softer metal than that coupling part - Google Patents

Abstract

The contact for an electrical connector contains an inner sleeve which comprises a coupling part (10A) having several elastically deformable fingers, a wire receiving part (10B) and an intermediate part. A back sleeve (30) is telescopically mounted on the wire receiving part (10B) of the inner sleeve and a front sleeve (20) is telescopically mounted on its coupling part (10a). The coupling part (10A) of the inner sleeve is made from a metal which is harder than that from which the wire receiving part (10B) is made. Therefore the wire receiving part (10B) is more deformable than the coupling part (10A) and the risk of breaking the connector while inserting the wire is thus reduced.

Description

Female contact for electrical connector
The present invention relates, in general, to electrical connectors and it relates more particularly to an electrical contact of the female type in three pieces for such connectors.

 Each of the two cooperating elements of an electrical connector generally comprises an envelope or case; a series of electrical contacts, each of which is connected to a separate incoming wire and an assembly of dielectric inserts used to rigidly or removably mount the electrical contacts in the casing of the connector element. In order to reduce the dimensions and the cost of the electrical connectors, there is a tendency to replace the contacts which were previously machined from a single piece with less expensive electrical contacts stamped and shaped from a metal sheet. and protected by one or more sleeves. Examples of such stamped and shaped contacts can be found in US Patents No. 4,072,394, issued February 7, 1978, No. 4,125,556, issued October 17, 1978, and No. 4,136. 923, issued on January 30, 1979. Currently, a three-piece contact is manufactured by stamping an inner sleeve in a sheet of beryllium copper, shaping it into a desired shape provided with several radially elastically deformable fingers, by subjecting it to a heat treatment to give the fingers the desired elasticity, then placing stainless steel sleeves on the front and rear parts of the inner sleeve respectively to protect the doi gts and to reinforce the rear wire receiving part. In a three-piece contact of the type shown in US Patent No. 4,072,394, the rear wire receiving part of the inner sleeve has several elongated slots to facilitate deformation symmetrical position of the sleeve when a wire is crimped into the sleeve. However, during the crimping of a wire in the contact, it sometimes happens that the external stainless steel sleeve breaks or cracks when it is pushed back into the slots.

 The present invention has the effect of a three-piece contact assembly which avoids this drawback and which has a rear wire receiving end which is softer and more easily deformed than that of the three-piece contact sets of the prior art.

 The present invention thus relates to a three-piece contact assembly characterized in that it comprises an inner sleeve which is bimetallic. The front coupling part which has elastically deformable fingers is made of beryllium copper and the rear wire receiving end is of a softer metal, for example copper.

 Therefore, an advantage of the present invention is that it has made a three-piece contact having a more easily deformable wire receiving end.

 Another advantage of the invention resides in that the copper part of the inner sleeve can be devoid of slots.

Other characteristics of the invention will appear on reading the description which follows and on examining the appended drawing in which:
Figs. 1 to 5 show the manner in which the inner sleeve of the contact assembly is formed;
Fig. 6 shows a three-piece contact assembly implementing the principles of the present invention; and
Fig. 7 shows another embodiment of a three-piece contact assembly implementing the principles of the present invention.

 Fig. 1, which will now be referred to, represents a side view of a stamped part used to form the inner sleeve of a contact. Preferably, the stamped part has a thickness of approximately 0.12 mm.

 Fig. 2 shows the configuration of the stamped part which has several fingers 14 at one end and whose central part has a groove 16. Several elongated slots can optionally be formed in the other end. The front part 10A of the stamped part is made of beryllium copper and its rear part LO is made of copper.

The front and rear portions 10A and 10B can be welded together, for example, by laser, or by rolling.

 Figs. 3 and 4 show the inner sleeve at successive stages of its shaping.

 Fig. 5 shows the inner sleeve 10 in the fully formed state.

 Fig. 6 shows a three-piece contact assembly which includes an inner sleeve 10, a front outer sleeve 20 and a rear outer sleeve 30. The role of the front sleeve 20 is to protect the elastically deformable fingers 14 of the inner sleeve 10 from damage. The rear sleeve 30, which is usually made of stainless steel, serves to facilitate obtaining a good crimp when a wire (not shown) is introduced into the rear wire receiving end of the contact assembly and is set. The shoulder 13 oriented towards the rear of the sleeve 20 forms a stop which serves to retain the connector assembly in an interior insert part of a connector element.

 Fig. 7 shows another type of three-piece contact assembly which includes the inner sleeve 10, an intermediate sleeve 40 which extends over the entire length of the inner sleeve 10 and an outer front sleeve 20 which protects the fingers 14 and the front coupling end of inner sleeve 10.

 Although preferred embodiments of the invention have been described, it will be apparent to those skilled in the art that modifications can be made to the invention as defined in the appended claims and that, in some cases, certain features of the invention can be used advantageously without the corresponding use of other characteristics. For example, slots may or may not be formed in the rear wire receiving portion of the inner sleeve 10. Therefore, it should be understood that the description and the drawing have been given only for the purpose of illustrating the principles of the invention and not to limit its scope.

Claims (1)

CLAIM 1 - A female contact assembly of the type comprising: an inner sleeve (10) in one piece having a front coupling part which comprises several elastically deformable fingers (14), a rear wire receiving part and an intermediate part; a rear sleeve (30) telescopically mounted on the rear part of the inner sleeve; and a front sleeve (20) telescopically mounted on the front part of the internal sleeve, characterized in that the internal sleeve has its rear part (10B) for receiving the wire made over its entire length from a first metal and its coupling part front (10A) made over its entire length from a second metal harder than the first metal, so that the rear wire receiving part is softer and more easily deformable than the front coupling part.