GB2112220A - Contact retention assembly - Google Patents

Abstract

A contact retention arrangement of the rear clip insertion and release type, has for each contact a retention clip (34) which is a one-piece eyelet having one or more inwardly extending contact retention fingers (42) formed thereon. The eyelet is spun or rolled at one end to form a mounting flange (40). The other end of the eyelet is inserted into a contact passage in a connector insulator (14) until it extends through that passage. The other end is then spun, stamped or rolled to form a second flange (38) which entraps the contact retention clip in the insulator. <IMAGE>

Description

SPECIFICATION Contact retention assembly This invention relates to an electrical connector, and especially to a contact retention assembly therefore.

Our British Patent No. 976723 discloses a contact retention assembly using a metal clip with forwardly and inwardly extending resilient contact retention fingers. In one commercial embodiment the clip is inserted into a contact cavity having a shoulder at one end, and a second insulator is mounted behind the first insulator to retain the clip therein. In a second version, the contact passage has shoulders at each end formed by an aluminum or zinc bushing mounted on a mold core pin during the insulator molding operation. The bushing is removed by etching in an acid or caustic bath. The contact retention clip is slightly collapsed and then inserted into the contact passage whereupon the clip expands and snaps into place between the shoulders.The first mentioned arrangement needs a two-piece insulator to retain the clip in the connector structure, while the second arrangement is relatively expensive due to the etching step needed to remove the aluminum or zinc bushing.

The Patent specification further discloses a two-piece contact retention clip structure comprising a forward tubular portion and an enlarged rear tubular portion embodying the contact retention fingers. The forward and rear portions of the clip structure are interlocked by overlapping flanges. After the clip structure is initially inserted into the contact passage, the forward end of its forward portion is spun over to form a flange which engages the front of the insulator, thus entrapping the structure in the insulator. This has the disadvantage that it needs separate forward and rear tubular portions which must be interconnected by flanges. Further, the rear portion of the structure has to be of greater diameter than the forward portion, due to the necessity of forming the interlocking flanges thereon.Thus the structure has a greater crosssection than a single piece clip, and so does not allow as high density contact arrangement in the connector. Further, the two-piece clip structure is necessarily longer than a one-piece clip, thus requiring a longer connector insulator.

It is an object of this invention to provide a contact retention assembly in which a one-piece retention clip may be retained in a single insulator without needing an etching step, which is relatively simple and inexpensive to make and assemble, and which permits a high density contact arrangement.

According to the invention there is provided a contact retention assembly, including an insulator having a passage therethrough from a forwardly facing surface to a rearwardly facing surface and a one-piece contact retention clip mounted in the passage, which clip has at least one forwardly and inwardly extending resilient contact retention finger, wherein the ends of the clip extend radially outwardly forming mounting flanges engaging the forwardly and rearwardly facing surfaces, respectively, to entrap the clip in the passage.

Thus neither a second insulator nor a second clip structure is needed to retain the clip in the contact passage. Preferably the clip is an eyelet having a continuous circumference which is relatively inexpensive to manufacture. One flange is formed by spinning, stamping or rolling one end of the eyelet. The other end of the eyelet is inserted into the contact passage and then deformed to form the second flange which entraps the eyelet in the insulator.

An embodiment of the invention will now be described with reference to the accompanying drawing, in which Fig. 1 is a fragmentary longitudinal section of a contact retention assembly embodying the invention, and Fig. 2 is a section similar to Fig. 1 showing one contact retention clip prior to insertion into the insulator.

Fig. 1 shows a contact retention assembly, generally designated 10, which includes a front insulator 12 and a rear insulator 14. A contact passage 1 6 extends from the front face 1 8 of the rear insulator 12 and a rear insulator 14. A contact passage 1 6 extends from the front face 1 8 of the rear insulator to the rear face 20 thereof. Counterbores 22 and 24 are formed at each end of the contact passage. The bottom of the counterbore 22 provides a forwardly facing surface 26 while the bottom of the counterbore 24 forms a rearwardly facing surface 28. The front insulator 12 has an opening 30 coaxial with the contact passage 1 6 and of a diameter substantially less than that of the passage 1 6, thus forming a rearwardly facing stop shoulder 32 at the right end of the contact passage.

The contact retention clip generally designated 34, is a cylindrical eyelet 36 having its opposite ends extending radially outwardly, forming mounting flanges 38 and 40. The flanges engage the surfaces 26 and 28, respectively, thus entrapping the clip within the passage. The clip has inwardly and forwardly extending contact retention fingers 42, two such fingers being shown by way of example. A contact 44 is mounted in the contact passage. The contact is shown as a pin contact, having a forward pin contacting portion 46 extending through the opening 30 in the front insulator 12. Alternatively, the contact could be a socket contact. The rear termination end 48 of the contact is connected to a conductor 50.An annular enlargement 52 formed in an intermediate portion of the contact abuts against the rearwardly facing stop shoulder 32 formed by the front insulator 12, thus restricting forward movement of the contact. The ends of the retention fingers 42 abut the rear of the enlargement 52 to restrict rearward movement of the contact in the passage 16. As is known a cylindrical tool may be inserted over the rear portion of the contact to spread the retention fingers 42 outwardly, thus permitting rearward removal of the contact from the assembly.

The eyelet 36 which forms the contact retention clip 34 may be stamped and rolled from flat stock or drawn. If it is stamped and rolled, the fingers 42 are struck from the flat stock prior to rolling the stock into cylindrical form. If the eyelet is formed by drawing a tube, the fingers may be formed by shearing the cylindrical wall of the tube prior to cutting off individual sections of the tube to form the eyelets. In the case of a drawn tube, the resulting eyelet has a continuous circumference except in the region of the retention fingers. That is, no longitudinal slit is formed in the eyelet. Rather than drawing a long tube and cutting to form the eyelets, individual eyelets may also be drawn and sheared to form the retention fingers.

As best seen in Fig. 2, the eyelet 36 is initially formed with a flange 40 so that the front end of the eyelet has a cylindrical configuration of a diameter which allows a sliding fit of the eyelet into the contact passage 1 6. The eyelet is mounted into the passage until the flange 40 engages the surface 28 on the insulator, in which position the forward end of the eyelet extends outwardly beyond the surface 26 of the insulator at the opposite end of the passage. Thereafter, the second flange 38 is formed on the eyelet by spinning, stamping or rolling the end of the eyelet.

Thus, the eyelet may be readily inserted into the rear insulator and then retained therein with a simple secondary operation. The front insulator 12 is not needed for retaining the clip in the rear insulator, but serves only as a stop member to restrict forward movement of the contact 44 in the rear insulator.

Thus, there is provided a one-piece contact retention clip which is inexpensive to make and easy to assemble into a connector insulator. The clip is relatively short, and has a relatively small diameter, so that it can be used in high density contact arrangements for connectors. Further, the spun or rolled over rear flange 40 provides a smooth lead-in chamfer 54 which facilitates insertion of a contact release tool into the rear of the clip.

Claims (8)

Claims

1. A contact retention assembly, including an insulator having a passage therethrough from a forwardly facing surface to a rearwardly facing surface; and a one-piece contact retention clip mounted in the passage, which clip has at least one forwardly and inwardly extending resilient contact retention finger, wherein the ends of the clip extend radially outwardly forming mounting flanges engaging the forwardly and rearwardly facing surfaces, respectively, to entrap the clip in the passage.

2. An assembly as claimed in claim 1, wherein the clip is an eyelet with a continuous circumference throughout its entire length except in the region of the finger.

3. An assembly as claimed in claim 1 or 2, wherein a second insulator is mounted in front of the first-mentioned insulator; which second insulator has an opening therethrough coaxial with the passage and of a diameter less than the inner diameter of the clip, thus providing a rearwardly facing radially extending stop shoulder spaced in front of the retention finger.

4. An assembly as claimed in claim 1,2 or 3, wherein a counterbore is provided at each end of the passage, the bottoms of the counterbores forming the forwardly and rearwardly facing surfaces, respectively; and wherein the ends of the clip extend into the counterbores.

5. An assembly as claimed in claim 1.2, 3, or 4, wherein at least the end of the clip adjacent to the rearwardly facing surface flares outwardly, providing an inner smooth lead-in chamfer into the clip to facilitate the insertion of a release tool from the rear of the insulator.

6. A contact retention assembly wherein a first insulator has a passage therethrough from a forwardly facing surface to a rearwardly facing surface thereof; wherein a one-piece contact retention clip is mounted in the passage, which clip is an eyelet having a continuous circumference and having at least one forwardly and inwardly extending resilient contact retention finger; wherein the ends of the clip extend radially outwardly to form mounting flanges engaging the forwardly and rearwardly facing surfaces, respectively, to entrap the clip in the passage; wherein a second insulator is mounted in front of the first insulator; and wherein the second insulator has an opening therethrough coaxial with the passage and of a diameter less than the inner diameter of the clip, thus providing a rearwardlyfacing radially extending stop shoulder spaced in front of the retention finger.

7. A contact retention assembly, substantially as described with reference to the accompanying drawing.

New claims or amendments to claims filed on 4th March 1983.

New claim

8. A contact retention assembly, such as used in an electrical connector, which includes an insulator having a cylindrical passage therethrough from a forwardly-facing surface to a rearwardly-facing surface, and a one piece cylindrical contact retention clip mounted in the passage, wherein the clip is an eyelet-like structure, with at least one forwardly and inwardly extending resilient contact retention finger struck or cut from the cylindrical body between the ends thereof, and wherein the ends of the clip extend radially outwardly to form mounting flanges at the end to engage the forwardly and rearwardly-facing surfaces of the insulator respectively, to entrap the clip in the passage.