GB2028009A

GB2028009A - An electrical lead cable for a plug or connector

Info

Publication number: GB2028009A
Application number: GB7925285A
Authority: GB
Original assignee: Ward and Goldstone Ltd
Current assignee: Volex PLC
Priority date: 1978-08-10
Filing date: 1979-07-19
Publication date: 1980-02-27
Also published as: GB2028009B

Abstract

An electrical lead cable (3) is provided for attachment to an electrical plug or connector at an end thereof. Secured to the end of the cable is an annular member (15) covered by a layer of electrically insulating material which is moulded around said end of the cable (3) to form a guard (17) therefor. This guard (17) is externally configured (as at 18, 19, 21) so as to be suitable for insertion into a casing (1) of the plug or connector and the annular member (15) and tends to bear any pulling force applied to the cable (3). <IMAGE>

Description

SPECIFICATION An electrical lead cable for a plug or connector The present invention relates to an electrical lead cable for attachment to an electrical plug or a connector.

In conventional plugs and connectors, the electrical lead cable is wired to each of the terminals of the plug or connector and the lead cable is usually secured to the body of the plug or connector by means of a clamp. Such a clamp may take the form of a strip of resilient material, which is tightened over the lead cable by screws from the exterior of the plug or connector casing, or a spring clip between resilient arms of which the lead cable is pushed to retain same. However, these conventional forms of clamp are not suitable for a non-rewirable plug or connector, which is moulded onto an electrical lead cable. Once such a plug or connector has been moulded onto a lead cable, the interior of the former cannot be exposed and it is essential that the lead cable is firmly retained in the connector or plug body.

According to a first aspect of the present invention there is provided an electrical lead cable for attachment to an electrical plug or connector at an end thereof, to which end is secured an annular member covered by a layer of electrically insulating material which is moulded around said end of the cable, said layer of material being externally configured so as to be suitable for insertion into a casing for the plug or connector so that after insertion the annular member will tend to bear any pulling force applied to the cable.

Preferably, the annular member comprises a metal or plastics band.

According to a second aspect of the present invention there is provided an electrical connector or plug wired to an electrical lead cable according to the first aspect of the present invention, the connector or plug comprising a casing with an aperture through which the cable is inserted whereby the annular member lies within the casing, the layer of electrically insulating material being configured so as to abut a rim of the casing defining the aperture interiorly of the casing.

An example of the present invention will now be described with reference to the accompanying drawings in which: Figure 1 is a view in partial cross-section of an electrical lead cable according to the present invention; Figure 2 is a sectional view on the line Il-Il of Figure 1; and Figure 3 is a longitudinal cross-sectional view, to a reduced scale, of a connector incorporating a cable as shown in Figures 1 and 2.

Referring to the drawings, the connector comprises a casing 1 moulded in two parts with an aperture 2 at one end thereof through which aperture 2 an electric lead cable 3 according to the invention can pass. Three adjacent apertures 4 are located at the other end of the casing 1 to form terminal sockets for the pins of a complementary plug for use with the connector. Adjacent the apertures 2, the interior of the casing 1 is divided into three compartments 5, 6 and 7 by partitions 8 and 9 moulded integrally with one part of the casing 1. These compartments 5,6 and 7 each accommodate one of three leads, live 10, neutral 11, or earth 12 of the cable 3 and the end of each lead 10, 11 or 12, is provided with a terminal connection 13to receive the appropriate pin of the plug.

The cable 3 comprises the three leads 10, 11 and 12 and is covered by an insulating plastics sleeve 14.

Adjacent the edge of the sleeve 14, an annular member comprising a metal or plastics band 15 is crimped around the cable 3 to a predetermined tightness. As shown in Figure 2, the band 15 is provided with a pair of projecting wings 16 which form keys for a layer of an electrically insulating material, such as an elastomeric or plastics material, which is moulded around the end of the cable 3. This layer of material forms a guard 17 for the cable 3.

As shown particularly in Figure 1, the guard 17 is externally configured so as to be suitable for insertion in the casing 1. A first portion 18 of the guard 17 is moulded around the band 15 and at this location is of substantially rectangular section. A second portion 19 of reduced thickness is located adjacent the portion 18 to define a groove 20 with a tapering third portion 21 of increased diameter, which portion 21 will lie outside the casing 1 of the connector. The groove 20 accommodates that portion of the casing 1 defining the aperture 2 and enables the portion 18 to abut the interior surface of the casing 1. In this way, the cable 3 cannot be withdrawn from the casing by pulling and the band 15 tends to relieve the cable 3 from bearing the strain associated with such pulling.

To prevent tampering with the interior of the connector, the two parts of the casing 1 are welded together after the cable 3 has been correctly wired thereto located therein. Hence, the connector is non-rewirable.

It will be appreciated that although a connector has been particularly described, the invention can be adapted to be equally applicable to electrical plugs and other connectors of different shape and construction.

1. An electrical lead cable for attachment to an electrical plug or connector at an end thereof, to which end is secured an annular member covered by a layer or electrically insulating material which is moulded around said end of the cable, said layer of material being externally configured so as to be suitable for insertion into a casing for the plug or connector so that after insertion the annular member will tend to bear any pulling force applied to the cable.

2. A cable as claimed in claim 1 in which the layer of insulating material is externally configured so as to be suitable for insertion into a casing for the plug or connector whereby the annular member would lie within the casing.

3. A cable as claimed in claim 1 or 2, in which the

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION An electrical lead cable for a plug or connector The present invention relates to an electrical lead cable for attachment to an electrical plug or a connector. In conventional plugs and connectors, the electrical lead cable is wired to each of the terminals of the plug or connector and the lead cable is usually secured to the body of the plug or connector by means of a clamp. Such a clamp may take the form of a strip of resilient material, which is tightened over the lead cable by screws from the exterior of the plug or connector casing, or a spring clip between resilient arms of which the lead cable is pushed to retain same. However, these conventional forms of clamp are not suitable for a non-rewirable plug or connector, which is moulded onto an electrical lead cable. Once such a plug or connector has been moulded onto a lead cable, the interior of the former cannot be exposed and it is essential that the lead cable is firmly retained in the connector or plug body. According to a first aspect of the present invention there is provided an electrical lead cable for attachment to an electrical plug or connector at an end thereof, to which end is secured an annular member covered by a layer of electrically insulating material which is moulded around said end of the cable, said layer of material being externally configured so as to be suitable for insertion into a casing for the plug or connector so that after insertion the annular member will tend to bear any pulling force applied to the cable. Preferably, the annular member comprises a metal or plastics band. According to a second aspect of the present invention there is provided an electrical connector or plug wired to an electrical lead cable according to the first aspect of the present invention, the connector or plug comprising a casing with an aperture through which the cable is inserted whereby the annular member lies within the casing, the layer of electrically insulating material being configured so as to abut a rim of the casing defining the aperture interiorly of the casing. An example of the present invention will now be described with reference to the accompanying drawings in which: Figure 1 is a view in partial cross-section of an electrical lead cable according to the present invention; Figure 2 is a sectional view on the line Il-Il of Figure 1; and Figure 3 is a longitudinal cross-sectional view, to a reduced scale, of a connector incorporating a cable as shown in Figures 1 and 2. Referring to the drawings, the connector comprises a casing 1 moulded in two parts with an aperture 2 at one end thereof through which aperture 2 an electric lead cable 3 according to the invention can pass. Three adjacent apertures 4 are located at the other end of the casing 1 to form terminal sockets for the pins of a complementary plug for use with the connector. Adjacent the apertures 2, the interior of the casing 1 is divided into three compartments 5, 6 and 7 by partitions 8 and 9 moulded integrally with one part of the casing 1. These compartments 5,6 and 7 each accommodate one of three leads, live 10, neutral 11, or earth 12 of the cable 3 and the end of each lead 10, 11 or 12, is provided with a terminal connection 13to receive the appropriate pin of the plug. The cable 3 comprises the three leads 10, 11 and 12 and is covered by an insulating plastics sleeve 14. Adjacent the edge of the sleeve 14, an annular member comprising a metal or plastics band 15 is crimped around the cable 3 to a predetermined tightness. As shown in Figure 2, the band 15 is provided with a pair of projecting wings 16 which form keys for a layer of an electrically insulating material, such as an elastomeric or plastics material, which is moulded around the end of the cable 3. This layer of material forms a guard 17 for the cable 3. As shown particularly in Figure 1, the guard 17 is externally configured so as to be suitable for insertion in the casing 1. A first portion 18 of the guard 17 is moulded around the band 15 and at this location is of substantially rectangular section. A second portion 19 of reduced thickness is located adjacent the portion 18 to define a groove 20 with a tapering third portion 21 of increased diameter, which portion 21 will lie outside the casing 1 of the connector. The groove 20 accommodates that portion of the casing 1 defining the aperture 2 and enables the portion 18 to abut the interior surface of the casing 1. In this way, the cable 3 cannot be withdrawn from the casing by pulling and the band 15 tends to relieve the cable 3 from bearing the strain associated with such pulling. To prevent tampering with the interior of the connector, the two parts of the casing 1 are welded together after the cable 3 has been correctly wired thereto located therein. Hence, the connector is non-rewirable. It will be appreciated that although a connector has been particularly described, the invention can be adapted to be equally applicable to electrical plugs and other connectors of different shape and construction. CLAIMS

3. A cable as claimed in claim 1 or 2, in which the annular member comprises a metal or plastics band.

4. A cable as claimed in any one of claims 1 to 3, in which the annular member has with projecting wings which provide a key for the layer of insulating material.

5. A cable as claimed in any one of claims 1 to 4, in which the layer of electrically insulating material forms a guard for the cable and is configured with a groove which can accommodate the rim of an aperture in the casing of the plug or connector through which aperture the cable is intended to be inserted into the casing.

6. A cable as claimed in claim 5, in which the groove is an annular groove located in an annular portion of the guard which is of reduced thickness as compared to the rest of the guard.

7. An electrical connector or plug wired to an electrical lead cable as claimed in claim 2, the connector or plug comprising a casing with an aperture through which the cable is inserted whereby the annular member lies within the casing, the layer of electrically insulating material being configured so as to abut a rim of the casing defining the aperture interiorly of the casing.

8. An electrical lead cable for attachment to an electrical plug or connector substantially as hereinbefore described with reference to the accompanying drawing.

9. An electrical connector wired to an electrical lead cable substantially as hereinbefore described with reference to Figure 3 of the accompanying drawing. ~~~~~~~~~~~~~~~~~~~