GB2199200A

GB2199200A - Electrical connector

Info

Publication number: GB2199200A
Application number: GB8728231A
Authority: GB
Inventors: Dr Peter Ian Lee; Nicholas Neely
Original assignee: Bowthorpe Hellerman Ltd
Current assignee: Bowthorpe Hellerman Ltd
Priority date: 1986-12-12
Filing date: 1987-12-02
Publication date: 1988-06-29
Also published as: GB8728231D0; GB8629764D0

Abstract

A heat-shrink cover member 18 has an electrically conductive lining 19 on its inner surface and is supplied with one end recovered about a coupling element 14, whilst its free end is left in expanded condition. The user then only has to insert the cable 20 through the cover member 18 and coupling element 14 and to recover the free end of the cover member about the cable. In the example shown, the coupling element 14 carries a locking ring 15 for spin-coupling the element 14 to the connector body 10, to which the cable conductors will be terminated. The electrically conductive lining 19 is such as to soften but not melt at the recover temperature of the cover member. <IMAGE>

Description

ELECTRICAL CONNECTOR This invention relates to an electrical connector and more particularly to the provision of an electrically shielding or screening cover member for sealing the electrical cable to the connector.

It is known to apply a heat-shrink cover member to certain.electrical connectors to seal the electrical cables to the connector body and thus prevent the ingress of dirt or moisture. In a particular type of electrical connector, the heat-shrink cover member is recovered about the cable on the one hand and about a coupling element on the other hand, and the coupling element can be e.g.

spin-coupled to the connector body (e.g. a plug body).

In some cases, the cover member may be required to provide electrical shielding or screening and, for these cases, it may have conductive lining over its inner surface.

In arrangements such as described above, the user has had the task of threading the cable through the heatshrink cover member and the coupling element, then positioning the cover member appropriately relative to the coupling element, and finally applying heat to the cover member to cause it to shrink and embrace the cable on the one hand and the coupling element on the other hand.

We have now discovered that it is possible to take a heat-shrink cover member which has a conductive lining, and recover one end of the cover member (e.g. in the factory) about the coupling element whilst leaving the other end of the cover member in expanded condition, such that the cable can subsequently be threaded through the cover member and coupling element in the field and the other end of the cover member finally recovered about the cable. This procedure can be adopted, recovering the opposite ends of the shielded cover member at completely different times, without affecting the integrity and effectiveness of the electrical shield or screen provided by the conductive lining.

Thus, in accordance with this invention as seen from one aspect, there is provided a method of terminating an electrical cable to an electrical connector, comprising inserting the cable through a heat-shrink cover member and a coupling element for the electrical connector, the cover member being provided with an electrically conductive lining over its inner surface and supplied with one end recovered about the coupling element and its other end in expanded condition, terminating one or more conductors of the cable to the electrical connector and coupling the coupling element to a body part of the electrical connector, the method also including the step of recovering said other end of the cover member about the cable after the cable has been inserted through the cover member and coupling element.

Also, in accordance with this invention as seen from a second aspect, there is provided a coupling element for an electrical connector together with a heat-shrink cover member, the heat-shrink cover member being provided with an electrically conductive lining over its inner surface and having been recovered at one of its ends about the coupling element, the cover member and coupling element being arranged to receive a cable or cables there through and the cover member being in expanded condition at its other end so as to be recoverable about the cable(s) when inserted through the coupling element and cover member.

Further, in accordance with this invention as seen from a third aspect, there is provided a method of assembling a heat-shrink cover member to a coupling element for an electrical connector, the heat-shrink cover member having an electrically conductive lining over its inner surface and the method comprising recovering one end only of the cover member about the coupling element whilst leaving the opposite end of the cover member in expanded condition.

The assembly operation for the user in the field is much simplified and enables a considerable saving in his time, because all he needs to do for applying the cover member is to pass the cable(s) through the cover member and coupling element, then apply heat to the still expanded end of the cover member so as to cause it to shrink down around the cable(s).' We have found that this procedure can be followed without affecting the integrity of the electrically conductive lining and therefore without impairing its effectiveness as a shield or screen.

In a preferred cover member, the electrically con-ductive lining comprises an adherent coating of a malleable alloy which, at the recovery temperature of the cover member, softens but does not melt, so that the cover member is able to shrink without affecting the integrity of the alloy coating, which remains adhered to to cover member. Thus the alloy does not exhibit a single melting point, but melts progressively over a broad temperature range. One suitable alloy is an indium-bismuth alloy and such a heat shrink article is disclosed and claimed in our U.K. patent application No.8604089 (Serial No.2 188 197A).

An embodiment of this invention will now be described by way of example only and with reference to the accompanying drawing, the single figure of which is a longitudinal section through an electrical connector which includes a coupling element and heat-shrink cover member in accordance with the invention.

The electrical connector illustrated comprises a connector body 10 which is circular in plan and in this example forms the plug part for a plug-and socket connection, the pins of the plug being shown at 12. A tubular metal coupling element 14 carries a locking ring 15 which is arranged for spin-coupling to a threaded portion 11 of the metal connector body 10, and the coupling element 14 has a periphery 16 about which one end of a heat-shrink shielded cover member 18 has been recovered.

This cover member is provided with an electrically conductive lining 19 over its inner surface extending from adjacent one end to adjacent the other end of the cover member. Preferably this lining comprises a coating of an indium-bismuth alloy which softens but does not melt at the recovery temperature of the cover member.

As supplied '(e.g. from the factory), the other and narrower end of the cover member 18 is still expanded, so that a cable 20 can be threaded through the cover member 18 and through the coupling element 14 (for eventual termination of its conductors to the pins 12, within the connector body 10). Once the cable has been thus inserted through the cover member and coupling element, heat can be applied to its narrower end to cause it to shrink down around the cable. After the cable conductors have been terminated to the plug pins 12, the coupling element 14 can be coupled to the connector body 10 by way of the locking ring 15, which forms an adaptor enabling the coupling element to be removably coupled to the body part 10.

In this way, the assembly of the heat-shrink shielded cover member and the coupling element to the cable is much simplified and this saves valuable time for the user, yet the integrity of the conductive lining (and therefore its shielding effectiveness) is not impaired by the twostage recovery of the respective ends of the cover member.

Claims

1. A method of terminating an electrical cable to an electrical connector, comprising inserting the cable through a heat-shrink cover member and a coupling element for the electrical connector, the cover member being provided with an electrically conductive lining over its inner surface and supplied with one end recovered about the coupling element and its other end in expanded condition, then terminating one or more conductors of the cable to a body part of the electrical connector and subsequently coupling the coupling element to said body part of the electrical connector, the method also including the step of recovering said other end of the cover member about the cable after the cable has been inserted through the cover member and coupling element.

2. , A method as claimed in claim 1, in which said.electrically conductiv-e lining is such as to soften but not melt at the recovery temperature of the cover member.

3. A method of terminating an electrical cable to an electrical connector, the method being as claimed in claim 1 and substantially as herein described with reference to the accompanying drawings.

4. A coupling element for an electrical connector together with a heat-shrink cover member, the heat shrink cover member being provided with an electrically conductive lining over its inner surface and having been recovered at one of its ends about the coupling element, the cover member and coupling element being arranged to receive a cable or cables therethrough and the cover member being in expanded condition at its other end so as to be recoverable about the cable(s) when inserted through the coupling element and cover member, and the coupling element being arranged for coupling to a body part of the connector fter one or more conductors of the cable have been terminated to said body part.

5. A coupling element and cover member as claimed in claim 4, in which said electrically conductive lining of the cover member is such as to soften but not melt at the recovery temperature of the cover member.

6. A coupling element together with a heat-shrink cover member, substantially as herein described with reference to the accompanying drawings.

7. A method of assembling a heat-shrink cover member to a coupling element for an electrical connector, the heat shrink cover member having an electrically conductive lining over its inner surface and the method comprising recovering one end only of the cover member about the coupling element whilst leaving the opposite end of the cover member in expanded condition, the coupling element being arranged for coupling to a body part of the connector after a cable has been passed through the cover member and coupling element and one or more conductors of the cable have been terminated to said body part.

8. A method of assembling a heat-shrink cover member to a coupling element as claimed in claim 7, in which said electrically conductive lining of the cover member is such as to soften but not melt at the recovery temperature of the cover member.

9. A method of assembling a heat-shrink cover member to a coupling element, the method being as claimed in claim 7 and substantially as herein described with reference to the accompanying drawing.