GB2110889A - Electrical contact - Google Patents

Abstract

A contact (24) for use in a connector (10) has a plastics retention ring (28) mounted on the contact body (26). The contact body is a stamped and formed longitudinally slit cylinder which has forward and rear sets of radially resilient retention fingers (44, 46) stamped from the wall of the cylinder. These fingers are bent outwardly so that their terminal ends face each other to form opposed stop shoulders (48, 50). The retention ring (28) has an inwardly extending annular flange, which is mounted between these shoulders to retain the ring on the contact body, and a resilient skirt for engaging shoulder 62 in insulator 12. Enlargement 34 can abut further shoulder 64. <IMAGE>

Description

SPECIFICATION Electrical contact This invention relates to an electrical contact, and especially to a contact having a retention element mounted on itto retain it in an electrical connector insulator.

One form of contact retention assembly used in the connector art is a front release system in which the contact is inserted into the connector insulator from the rear and the retention mechanism for the contact is released from the front to allow withdrawal of the contact from the rear. This mechanism may use a contact retention clip mounted in the contact passage, or carried by the contact. This invention relates to the latter form of retention arrangement.

Typically, in such an arrangement, the retention clip is a stamped and rolled metal ring mounted on the contact and having rearwardly and outwardly extending spring tines which engage a forwardly facing shoulder in the contact passage to restrict rearward movement of the contact therein. The tines are released to remove the contact rearwardly from the insulator by inserting a tubular release tool into the contact passage from the front of the insulator.

As disclosed in U.S. Patent No. 3,078,439, such a retention clip may be mounted on a machined contact by providing an inwardly extending tab or flange on the clip which fits into an annular groove in the contact body to retain the clip on the body. U.S.

Patent No. 3,009,130 shows a front release contact retention arrangement in which the contact retention element is staked onto the contact body. U.S. Patent No. 3,172,721 shows a contact retention clip in the form of a longitudinally-split plastics ring having an outwardly-extending skirt providing a retention tine, and an inwardly extending annular flange fitting in an annular groove in a machined contact.

An object of this invention is to provide a simple and inexpensive means for mounting a contact retention clip on a contact body which allows the use of a stamped and formed, ratherthan machined, contact body and permits the retention clip to be readily installed on the contact body, and to be removed if it is damaged.

According to the invention, there is provided an electrical contact, including: (a) a stamped and formed longitudinally slit generally cylindrical contact body having an intermediate portion between a forward mating end and a rear termination end; (b) a forward set of radially resilient, rearwardly extending retention fingers stamped from the wall of said intermediate portion and bent outwardly to terminate in rearwardlyfacing stop shoulders; (c) means on said intermediate portion spaced behind said forward set of fingers to provide a forwardly facing stop shoulder; and (d) a contact retention clip mounted on said intermediate portion, said clip having a resilient outwardly extending contact retention element and an inwardly extending flange; said flange being positioned between the rearwardly facing stop shoulders and said forwardly facing stop shoulder, whereby the clip is restrained against axial movement on said body, the retention fingers deflecting inwardly when said clip is pushed rearwardly over said body and snapping outwardly when said flange passes said fingers.

Thus, an inexpensive stamped and formed contact body may be used rather than a machined contact body in which an annular groove must be cut to receive the contact retention clip. Our retention fingers are easily formed by stamping and bending the sheet material from which the contact body is formed when forming of the contact body. Further, the contact retention clip may be readily mounted on the contact body by simply slipping it rearwardly over the front set of retention fingers, which deflect radially inwardly until the clip is behind the fingers.

An embodiment of the invention will now be described with reference to the drawing, in which Fig.1 is a fragmentary, partial longitudinal section through a connector with a contact embodying this invention; Fig. 2 is a longitudinal section through the retention clip used on the contact body of a contact as in Fig. 1, and Fig. 3 is a rear view of the contact retention clip.

Fig. 1 shows an electrical connector member 10, using the contact embodying this invention. The connector has an insulator 12 with a contact passage 14extendingfrom its front face 16to its rear face 18.

An elastomeric grommet 20 on the rear face 18 of the insulator has a passage 22 aligned with the contact passage 14.

The contact 24 has a contact body 26 and a plastics retention clip or ring 28, and is in the passage 14. The contact body has a forward mating end 30, shown as a pin contact, an intermediate portion 32 between the forward mating end and an annular enlargement 34, and a rear termination end 36 adjacent to the rear face 18 of the insulator 12. The forward mating end extends forwardly from the front face 16 of the insulator. While this end is shown as a pin contact, it could also be a socket contact, in which case its end is preferably behind the front face of the insulator.

The rear termination end 36 of the contact body has a crimp barrel shown as connected to an insulated conductor 38 extending outwardly through the passage 22 in the grommet 20. The passage 22 has sealing ribs 40 which engagethe insulation on the conductor.

The contact body 26 is stamped and formed from sheet stock and rolled to provide a longitudinal slit 42. When the body is being formed, forward and rear sets of retention fingers, 44 and 46 respectively, are cut from the wall of the body. Each set may include three or more individual fingers. As seen in Fig. 1, the fingers 44 are bent outwardly and extend This print embodies corrections made under Section 117(1) of the Patents Act 1977.

The drawing(s) originally filed was/were informal and the print here reproduced is taken from a later filed formal copy.

rearwardly, so that their rear ends provide rearward ly facing stop shoulders 48.

The rear set of retention fingers are spaced behind the front set, and are bent outwardly and extend forwardly to provide attheirforward ends forwardly facing stop shoulders 50. Thus, the sets of stop shoulders 48 and 50 define in effect an annular channel on the contact body, without needing to use a solid contact body machined to form a groove, as used in some of the known arrangements discussed above.

The plastics retention ring 28 comprises a general ly cylindrical body 52 having an inwardly extending annular flange 54 and a rear outwardly extending skirt 56 formed with longitudinally extending slots 58 three being shown in Fig. 3. Since the skirt is formed of plastics, it is radially deflectable. The axial length of the flange 54 is such that it fits into the channel between the stop shoulders 48 and 50 on the contact body 26. The retention ring is mounted on the contact body and pushing it rearwardly over the forward set of fingers 44, causes the fingers to deflect inwardly until the flange 54 passes the rear ends of the fingers, whereupon the fingers snap out to trap the flange, and thus the retention ring, between stop shoulders 48 and 50 on the contact body.

Because the fingers 44 deflect inwardly when the ring is mounted on the contact body, it is not necessaryforthe ring to be longitudinally slit throughout its length to allow the ring to be mounted on the contact body. As the ring need not be slit, there is less chance of the ring becoming dislodged from the contact body when handling the contact.

The contact is inserted into the contact passage 14 from the rear of the insulator. The contact passage has an inwardly extending flange 60 providing a forwardly facing shoulder 62 and a rearwardly facing shoulder 64. As the contact moves forwardly through the contact passage, the retention ring passes through the opening defined by the flange 60, causing the slotted skirt 56 of the ring to deflect inwardly. Afterthe skirt passes the shoulder 62 on the flange 60, the skirt expands outwardly to the position shown in Fig. 1, whereupon the end of the skirt abuts the shoulder, preventing the ring and, hence, the contact body upon which it is mounted, from being pushed rearwardly through the contact passage. The annular enlargement 34 on the contact body provides a forwardly-facing annular abutment surface which engages the shoulder 64 to limit forward movement of the contact in the passage.

Thus, it will be seen that out contact is inexpensive to manufacture since the retention ring 28 may be easily molded and the contact body 26 may be stamped and formed with the retention fingers 44 and 46 to mount the ring on the contact body.

Further, the ring may be easily assembled on the contact body by simply pushing it onto the forward end of the body. Also, the contact of the invention is capable of withstanding high push-out forces.

Claims (7)

1. An electrical contact, including: (a) a stamped and formed longitudinally slit generally cylindrical contact body having an intermediate portion between a forward mating end and a rear termination end; (b) a forward set of radially resilient, rearwardly extending retention fingers stamped from the wall of said intermediate portion and bent outwardly to terminate in rearwardly facing stop shoulders; (c) means on said intermediate portion spaced behind said forward set of fingers to provide a forwardly facing stop shoulder; and (d) a contact retention clip mounted on said intermediate portion, said clip having a resilient outwardly extending contact retention element and an inwardly extending flange; said flange being positioned between the rearwardly facing stop shoulders and said forwardly facing stop shoulder, whereby the clip is restrained against axial movement on said body, the retention fingers deflecting inwardly when said clip is pushed rearwardly over said body and snapping outwardly when said flange passes said fingers.

2. A contact as set forth in claim 1, wherein said means is a rear set of radially resilient, forwardly extending retention fingers stamped from the wall of said intermediate portion and bent outwardly, the forward ends of said fingers providing said forwardly facing stop shoulder.

3. A contact as set forth in claim 1 or 2, and including an annular enlargement on its body between said rear set of retention fingers and said rear termination end, said enlargement providing a forwardly facing annular abutment surface.

4. An electrical contact, substantially as de- scribed with reference to the accompanying drawing.

New claims or amendments to claims filed on 7 Feb 1983

5. An electrical contact, such as is used in an electrical connector, which includes: (a) a stamped and formed longitudinally slit generally cylindrical body having an intermediate portion between a forward mating end and a rearwards termination end; (b) a forward set of radially resilient, rearwardly-extending retention fingers stamped from the wall of said intermediate portion and bent outwardly to terminate in rearwardly-facing stop shoulders; (c) means on said intermediate portion spaced behind the forward set of fingers to provide a forwardly4acing stop shoulder; and (d) a contact retention clip made of an electrically insulating material mounted on the intermediate portion, wherein the clip is generally cylindrical and is not longitudinally split, wherein the clip has a resilient outwardly-extending contact-retention element and an inwardly-extending flange, wherein the clip when mounted on the contact is positioned between the rearwardly-facing stop shoulders and the forwardly-facing stop shoulder. so that the clip is restrained against axial movement on the body, and wherein the retention fingers deflect inwardly when the clip is pushed rearwardly over the contact body and snap outwardly when the flange passes the lingers.

6. A contact as set forth in claim 5, wherein the means on the intermediate portion is a rear set of radially-resilient, forwardly-extending retention fingers stamped from the wall of the intermediate portion and bent outwardly, the forward ends of the said fingers providing the forwardly-facing stop shoulder, and wherein there is an annular enlargement on the contact body between its said rear set of fingers and its said termination end, which enlargement provides a forwardlyJacing annular abutment surface.

7. An electrical connector element, which contains a number of contacts, each as claimed in any one of the preceding claims.