GB2337878A

GB2337878A - Connector for cable with electrical shield

Info

Publication number: GB2337878A
Application number: GB9918533A
Authority: GB
Inventors: Peter Ian Lee; Roger Philip Bonas
Original assignee: Bowthorpe PLC
Current assignee: Bowthorpe PLC
Priority date: 1999-08-06
Filing date: 1999-08-06
Publication date: 1999-12-01
Anticipated expiration: 2019-08-06
Also published as: GB9918533D0; EP1075044A1; AU3532100A; CA2308752A1; GB2337878B

Abstract

An electrical connector part (20) for terminating an electric cable (C) comprises a body part (22) which houses a conductor terminating means (24) and is formed with a circumferential surface (30) for overlapping by the shield (S) of the cable, and a spring (40) in the form of a coiled metal ribbon for wrapping around the portion of cable shield which overlaps the circumferential surface (30). The body part (22) may be formed as one-piece or as two pieces screwed together, but the usual backshell of the connector is dispensed with. An aperture (23) may give access to shields of cable cores to the surface (30) for terminating the core shields together with the cable shield.

Description

2337878 Electrical connector The present invention relates to electrical

connectors. One known type of electrical connector comprises two parts, a first part which is usually fixed or mounted to an equipment housing, and a second part which terminates the end of a cable which is to be connected to electrical equipment within the equipment housing. Typically the second part carries a rotatable coupling nut for screw-threaded engagement with a thread formed on the first part, for coupling the two parts of the connector together. Hitherto, the second part of the connector has included a body into the rear end of which the conductors of the cable pass, for termination within the body, and a backshell or backshell adapter which closes the rear end of the body: the backshell itself carries a rotatable coupling nut for screw-threaded engagement with a thread formed on the body of the second connector part, for coupling the backshell to the connector. The shielding braid of the cable is terminated onto the backshell: UK patent No. 2,208,049 discloses and claims a connector backshell in which the cable shield embraces a body portion of the backshell and is held in place by a constant force spring wrapped around the shield.

We have now devised an improved connector arrangement.

In accordance with the present invention, there is provided an electrical connector which comprises first and second parts to be coupled together, at least the second part being arranged to terminate an electrical cable and comprising a body part which houses means for receiving and terminating the ends of the conductors of the cable and includes an outer circumferential surface for overlapping by a shield of the cable, and a spring in the form of a coiled metal ribbon for wrapping around the portion of cable shield which overlaps said outer circumferential surface of said body part.

Also in accordance with the present invention, there is provided an electrical connector part which is arranged for coupling to a mating connector part and comprises a body part which houses means for receiving and terminating the ends of the conductors of the cable, said body part including an outer 2 circumferential surface for overlapping by a shield of the cable, and a spring in the form of a coiled metal ribbon for wrapping around the portion of cable shield which overlaps said outer circumferential surface of said body part.

The body part of the connector may be f ormed as onepiece, or it may be formed as two pieces screwed together.

The two parts of the connector may couple together by means of a rotatable coupling nut carried by either of the parts, arranged to engage with a screw thread formed on the other part. Instead, other forms of coupling between the two parts may be employed, for example a bayonet coupling. Embodiments of the present invention will now be described by way of examples only and with reference to the accompanying drawings, in which: 15 Figure 1 is a schematic longitudinal section through a first embodiment of an electrical connector in accordance with the present invention; and Figure 2 is a similar section through the cable terminating part of a second embodiment of connector. 20 Referring to Figure 1 of the drawings, there is shown an electrical connector which comprises a first part 10 fixed to an equipment housing H and a second part 20 which terminates a cable C. The second part comprises a body 22 which is tubular and receives a termination arrangement 24 for the ends of the cable conductors: at the front end of the connector part 20, the termination arrangement 24 is shown as including a plurality of electrical sockets 26 to receive corresponding pins 16 of a termination arrangement 14 of the connector part 10; instead, the sockets may be provided in the termination arrangement of the connector part 10 and the pins on the termination arrangement of the connector part 20.

A rotatable coupling nut 28 is carried by the body 22 of the connector part 20, adjacent the front end thereof, and is arranged for screwthreaded engagement with a screw thread 18 on an outer cylindrical surface of the connector part 10.

Towards its rear end, the body 22 of the connector part 20 is formed with a cylindrical outer surface 30, disposed between two annular ribs 31,32. The shielding braid S of the cable is overlapped around the surface 30 of the body 22 of the 3 connector part 20 and is held in place by a constant force spring 40 wrapped around it a number of turns.

The body 22 of the connector part 20 may be formed of metal, and so provide shielding continuity from the cable to the equipment housing H. Instead, the body 22 of the connector part 20 may be formed of plastics or other non-conductive material, then provided with a conductive shielding layer or with shielding-continuity conductors against which the cable shield S is urged by the constant force spring.

The body 22 of the connector part 20 is tubular but is not necessarily circular in section throughout its length: for example, the forward portion which houses the termination arrangement 24 may be square or oval.

In the embodiment of Figure 1, the body 22 of connector part 20 is formed as one-piece. In the embodiment of Figure 2, the connector part 20 corresponds with that shown in Figure 1, except that the body 22 is formed as two pieces 22a,22b which screw together: the forward piece 22a houses the termination arrangement 24 and carries the coupling nut 28 or other coupling means, whilst the rearward piece 22b is formed with the ribs 31,32 and intervening cylindrical surface 30 for receiving the end of the cable shield over this constant force spring 40.

It will be appreciated that, in each of the embodiments described above, because the second connector part 20 dispenses with the requirement for a backshell or backshell adaptor, the connector part is of simpler construction, lighter in weight, and of reduced cost. Moreover, the arrangement reduces the number of joints in the electrical shield, which must be maintained in continuity from the cable to the equipment housing, and so improves the overall shielding performance.

The body 22 of the connector part 20 may be formed with at least one slot 23, shown in the examples as extending circumferentially: this slot enables inner shields of the cable, which are sometimes provided around one or more groups of the cable conductors, to be brought out onto the outer surface 30, against which these shields or braids are embraced to effect continuity of the shielding by the constant force spring 40.

4

Claims

1) An electrical connector which comprises first and second parts to be coupled together, at least the second part being arranged to terminate an electrical cable and comprising a body part which houses means for receiving and terminating the ends of the conductors of the cable and includes an outer circumferential surface for overlapping by a shield of the cable, and a spring in the form of a coiled metal ribbon for wrapping around the portion of the cable shield which overlaps said outer circumferential surface of said body part.

2) A connector as claimed in claim 1, in which one of the two parts of the connector carries a rotatable coupling nut arranged to engage with a screw thread formed on the other part of the connector.

3) A connector as claimed in claim 1, comprising a bayonet coupling for coupling the two parts of the connector together.

4) A connector as claimed in any preceding claim, in which said body part of said second connector part is formed as one piece.

5) A connector as claimed in any one of claims 1 to 3, in which said body part of said second connector part comprises a forward piece and a rearward piece, which are formed with complementary screw threads for direct engagement together by rotation relative to each other.

6) A connector as claimed in claim 5, in which said rearward piece of said second connector part is formed with said circumferential surface for overlapping by said shield of the cable.

7) An electrical connector substantially as herein described with reference to Figure 1 or 2 of the accompanying drawings.

8) an electrical connector part which is arranged for coupling to a mating connector part and comprises a body part which houses means for receiving and terminating the ends of the conductors of a cable, said body part including an outer circumferential surface for overlapping by a shield of the cable, and a spring in the form of a coiled metal ribbon for wrapping around the portion of cable shield which overlaps said outer circumferential surface of said body part.

9) A connector part as claimed in claim 8, carrying a 10 rotatable coupling nut arranged to engage with a screw head formed on said mating connector part.

10) A connector part as claimed in claim 8, formed with a screw thread for engagement by a rotatable coupling and carried by said mating connector part.

11) A connector part as claimed in claim 8, arranged to couple to said mating connector part by means of a bayonet coupling.

12) A connector part as claimed in any one of claims 8 to 11, in which said body part is formed as one-piece.

13) A connector part as claimed in any one of claims 8 to 11, in which said body part comprises a forward piece and a rearward piece, which are formed with complementary screw threads for direct engagement together by rotation relative to each other.

14) A connector part as claimed in claim 13, in which said rearward piece of said body part is formed with said circumferential surface for overlapping by said shield of the cable.

15) An electrical connector part as claimed in claim 8 and 30 substantially as herein described with reference to Figure 1 or 2 of the accompanying drawings.