GB1574799A

GB1574799A - Electrical connectors

Info

Publication number: GB1574799A
Application number: GB33255/76A
Authority: GB
Original assignee: HAILEY WELDING PRODUCTS Ltd
Current assignee: HAILEY WELDING PRODUCTS Ltd
Priority date: 1977-11-07
Filing date: 1977-11-07
Publication date: 1980-09-10

Description

(54) IMPROVEMENTS IN OR RELATING TO ELECTRICAL CONNECTORS (71) We, HAILEY (WELDING PRO DUCTS) LIMITED, a British Company of P.O. Box 16, Saffron Waldon, Essex do hereby declare the invention, for- which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to electrical connectors and connector assemblies particularly for use in connecting cables in the welding industry in which low voltage and high current conditions prevail.

According to the present invention there is provided an electrical connector comprising a female element having an internal surface and a cooperating male element releasably secured to the female element and, when so secured having an external surface located within said internal surface to define therewith a lomgitudinally extending open ended annular electrical conductor receiving chamber whose cross sectional area reduces along the length of the chamber from an open end thereof towards a point intermediate the ends thereof and then increases from said point towards the other end of the chamber.

Preferably the said annular chamber is constituted as a volume of revolution. Preferably also the chamber, in a first part thereof between the said open end and the said intermediate point is formed by a substantially cylindrical internal surface of the female element and a substantially conical external surface of the male element and preferably also. the chamber. in a second part thereof extending between the said intermediate point and the said other end of the chamber. is defined between an internal surface portion of the female element which flares outwardly with respect to the axis of the chamber as it extends towards said other end while the corresponding external surface portion of the male member tapers witll respect to said axis as it extends towards said other end.

The invention further proposes to include means for securing the said male and female elements in fixed relation to each other, and preferably these means comprise cooperating screw thread elements respectively integral with the male and female elements and by which the two elements may be located in fixed relation with respect to each other.

According to a preferred aspect of the invention one of the said elements, preferably the male element, is integral with a plug or socket member of an electrical connector.

An embodiment of the invention will now be described by way of example only with reference to Figures 1 and 2 of the accompanying drawings which are cross sectional views respectively, of a plug member and of a socket member of a connector assembly each including an electrical connector.

In the illustrated embodiment of the invention both the plug member 1 and the socket member 2 have an electrical connector 3 formed of electrically conductive material and including a female element 4 in the form of a tubular element having a cylindrical external surface 5 and an internal surface 6.

The internal surface 6 is substantially cylindrical as it extends from one open end 7 of the female element towards the other end thereof 8. At a point 9 approximately midway between the ends of the female element the internal surface 6 of the female element has a radially inward projection after which the surface 6 flares outwardly with respect to the longitudinal axis of the element for a relatively short distance and then continues as an internal screw thread to the end 8 of the female element 3.

Located within the internal surface 6 of the female element is a portion 11 of a male element 10 of the electrical connector 3.

This portion 11 of the male element extends from the end 8 of the female element towards the open end 7 of the female element 4 but not over the entire length of the female element 4. The external surface 12 of this portion 11 of the male element 10 comprises a conical portion 13 situated adjacent to the open 7 of the female element 4 and having a diameter which increases from zero close to said open end 7 to a maximum at a point corresponding to the point 9 at which the internal surface 6 of the female element 4 begins to flare outwardly.

From this point the external surface of the male element tapers inwardly towards the axis of the element as it extends towards end 8 of the female element 4, that is, the cross section of the male element reduces over a length corresponding to the flared out portion of the internal surface 6 of the female element. The last part 14 of the external surface 12 of this portion 11 of the male element 10 is formed as a screw thread co-operating with the correspondingly screw threaded portion of the internal surface 6 of the female element 4.

Forming an integral part of the male element is a socket part 15 (Figure 2) or a plug part 16 (Figure 1) in accordance with the function of the whole connector. This socket or plug part has a flange 17 formed at the junction of the screw threaded surface portion 14 of the male element and this socket or plug part and the screw threaded end 8 of the female element 4 abuts against this flange 17. The male and female elements of the connector are surrounded by rubber shrouds 18, 19.

With the male and female elements in the assembled position just described the respective internal and external surfaces form together to constitute an annular open ended chamber 20. The cross sectional area of this chamber reduces along the length thereof from the open end towards the point 9 intermediate the ends thereof and then increases from this intermediate point towards the other end of the chamber to form a generally toroidal chamber part with a narrow entrance corresponding to the cross sectional area pf the chamber at the said intermediate point 9.

In the use of the electrical connector just described with a cable used in the welding industry the sheath is removed from the cable for approximately one inch from its free end. The appropriate rubber shroud 18 or 19 and a female element 4 are then slipped over the free end of the cable. The pointed conical end of the male element 10 is then pushed into the centre of the cable core consisting ocf individual strands so that the individual strands extend over the external surface 12 of the male element as far as the screw thread portion 14 thereof. The female element is then pushed up over the male element until the screw threaded elements of the male and female portions come into contact. The female element is then rotated with respect to the male element to screw the female element onto the male element until the abutment flange 17 is reached. During this latter operation the free ends of the strands of the cable are compressed between the external surface 12 of the male element and the internal surface 6 of the female element and the extreme ends become located in the toroidal chamber part. Finally the rubber shroud 18, 19 is fitted into position over the co-operating male and female elements. The electrical connector as described above provides a quick and positive electrical connection between the able and the plug or socket member of the connector with the minimum number of parts and the whole becomes fully insulated and protected when the rubber shroud is fitted into position. Furthermore the shape of the annular chamber and the manner in which the connector may be fitted to the strands of the cable ensures good resistance to axial displacement of the connector with respect to the cable.

WHAT WE CLAIM IS: 1. An electrical connector comprising a female element having an internal surface and a co-operating male element releasably secured to the female element and, when so secured, having an external surface located within said internal surface to define therewith a longitudinally extending open ended annular electrical conductor receiving chamber whose cross sectional area reduces along the length of the chamber from an open end thereof towards a point intermediate the ends thereof and then increases from said point towards the other end of the chamber.

2. A connector according to claim 1 wherein the said annular chamber is constituted as a volume of revolution.

3. A connector according to claim 1 or claim 2, wherein the chamber in a first part thereof between the said open end and the said intermediate point. is formed by a substantially cylindrical internal surface of the female element and a substantially conical external surface of the male element.

4. A connector according to any preceding claim wherein the chamber, in a second part thereof extending between the said intermediate point and the said other end of the chamber, is defined between an internal surface portion of the female element which flares outwardly with respect to the axis of the chamber as it extends towards said other end while the associated external surface portion of the male member tapers inwardly with respect to said axis as it extends towards said other end.

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. This portion 11 of the male element extends from the end 8 of the female element towards the open end 7 of the female element 4 but not over the entire length of the female element 4. The external surface 12 of this portion 11 of the male element 10 comprises a conical portion 13 situated adjacent to the open 7 of the female element 4 and having a diameter which increases from zero close to said open end 7 to a maximum at a point corresponding to the point 9 at which the internal surface 6 of the female element 4 begins to flare outwardly. From this point the external surface of the male element tapers inwardly towards the axis of the element as it extends towards end 8 of the female element 4, that is, the cross section of the male element reduces over a length corresponding to the flared out portion of the internal surface 6 of the female element. The last part 14 of the external surface 12 of this portion 11 of the male element 10 is formed as a screw thread co-operating with the correspondingly screw threaded portion of the internal surface 6 of the female element 4. Forming an integral part of the male element is a socket part 15 (Figure 2) or a plug part 16 (Figure 1) in accordance with the function of the whole connector. This socket or plug part has a flange 17 formed at the junction of the screw threaded surface portion 14 of the male element and this socket or plug part and the screw threaded end 8 of the female element 4 abuts against this flange 17. The male and female elements of the connector are surrounded by rubber shrouds 18, 19. With the male and female elements in the assembled position just described the respective internal and external surfaces form together to constitute an annular open ended chamber 20. The cross sectional area of this chamber reduces along the length thereof from the open end towards the point 9 intermediate the ends thereof and then increases from this intermediate point towards the other end of the chamber to form a generally toroidal chamber part with a narrow entrance corresponding to the cross sectional area pf the chamber at the said intermediate point 9. In the use of the electrical connector just described with a cable used in the welding industry the sheath is removed from the cable for approximately one inch from its free end. The appropriate rubber shroud 18 or 19 and a female element 4 are then slipped over the free end of the cable. The pointed conical end of the male element 10 is then pushed into the centre of the cable core consisting ocf individual strands so that the individual strands extend over the external surface 12 of the male element as far as the screw thread portion 14 thereof. The female element is then pushed up over the male element until the screw threaded elements of the male and female portions come into contact. The female element is then rotated with respect to the male element to screw the female element onto the male element until the abutment flange 17 is reached. During this latter operation the free ends of the strands of the cable are compressed between the external surface 12 of the male element and the internal surface 6 of the female element and the extreme ends become located in the toroidal chamber part. Finally the rubber shroud 18, 19 is fitted into position over the co-operating male and female elements. The electrical connector as described above provides a quick and positive electrical connection between the able and the plug or socket member of the connector with the minimum number of parts and the whole becomes fully insulated and protected when the rubber shroud is fitted into position. Furthermore the shape of the annular chamber and the manner in which the connector may be fitted to the strands of the cable ensures good resistance to axial displacement of the connector with respect to the cable. WHAT WE CLAIM IS:

1. An electrical connector comprising a female element having an internal surface and a co-operating male element releasably secured to the female element and, when so secured, having an external surface located within said internal surface to define therewith a longitudinally extending open ended annular electrical conductor receiving chamber whose cross sectional area reduces along the length of the chamber from an open end thereof towards a point intermediate the ends thereof and then increases from said point towards the other end of the chamber.

5. A connector according to any preced

ing claim further comprising means for securing the said male and female elements in fixed relation to each other.

6. A connector according to claim 5 wherein said means comprise co-operating screw thread elements respectively integral with the male and female elements and by which the two elements may be located in fixed relation with respect to each other.

7. A connector according to any preceding claim wherein one of the said elements, preferably the male element is integral with a plug or socket member of a connector assembly.

8. A connector assembly comprising a plug member and a co-operating socket member each of which has an electrical connector according to any preceding claim for securing the respective member to the current carrying part of an electric cable.

9. An electrical connector substantially as herein described with reference to Figure 1 or Figure 2 of the accompanying drawing.