Title of Invention

CABLE CONNECTOR

Abstract

An electric cable connector (10) is provided as a metal tape formed into a radially-resilient helix, which preferably has a roughened inner surface (18). The connector may be screwed onto the stranded conductors (20) of cable (22) at an end thereof, and this action tends to remove any oxide film on the conductors. The inwards pressure of the connector (10) enhances current equalisation between the conductive strands of the cable.

Full Text

Cable Connector This invention relates to a cable connector, and in particular to a connector for electrical power cables, especially cables whose conductor cross-sectional area is relatively large, for example greater than 10 mm2, for use in the generation, transmission or distribution of electric power. Connections to electrical cables, for example to provide terminations thereof, may be provided by a bolt-on connector, or by a crimped connector. Whilst these are successfully used, a tool, such as a screwdriver or a crimping tool is required. It is an object of the present invention to provide for electrical connection to an electrical cable in a simpler manner, which may be especially useful for power cables having conductors of relatively high cross-sectional area, for example more than 5 mm2 or more than 10 mm2 and up to 16 mm2, or up to 25 mm2, or up to 35 mm2, capable of carrying in use relatively high currents, for example 30 or 50 to 100 amps or more. hi accordance with one aspect of the present invention, there is provided an electric cable connector comprising a metal tape that is wound so as to form a radially-resilient helix. By \ "tape" is meant an elongate strip whose width is at least twice its thickness, preferably at least three to five times its thickness, and especially ten or more times its thickness, provided that its thickness is sufficient, as will be readily apparent to suitably experienced persons, to render the tape adequately stiff and resilient for the present purpose. It will be understood that, in order to be "radially resilient", the turns of the helix are arranged to be movable relative to one another and are not fastened together at their edges or overlapping parts. The connector of the invention can be applied to the exposed conductor of an electric cable without using any special tools, whereby the operator using just the hands can twist and screw the helical connector onto the cable. Furthermore, the action of twisting the helical metal tape onto the conductor automatically brushes and cleans the conductor, for example removing any oxide film that may have been formed on the surface thereof. It will be appreciated that, in contrast with the screw-on and crimped connectors, this can conveniently result in a good electrical connection without the need for a separate cleaning of the cable conductor. The connector may be mounted at the end of a cable, to provide a termination thereof, or may be attached part-way along a centre-stripped insulated cable, for example to form a branch-off. The resilient nature of the metal tape ensures that a tight fit, and thus a good electrical connection, is made onto the cable conductor. The connector of the present invention finds particular advantage when used with a stranded conductor, since it forces the strands into good contact with each other thus equalising the distribution of current flowing there-through. The helical construction of the connector also makes it inherently useful for conductors of different diameter, thus reducing the number of connectors that need to be kept in inventory. Close conformity with the conductor can thus be obtained for a variety of diameters. Preferably, the helix is tapered, and may be stepped or of continuous tapering along at least part of the length of the connector. It will be appreciated that the tapering will assist in the mounting of the connector onto the conductor of the cable, and of the cleaning of the conductor surface. Furthermore, this configuration assists in the range-taking ability of the resilient helical structure. The cleaning of the surface of the conductor when the connector is fitted thereon is improved if the internal surface of the tape is roughened, for example being formed to have a mesh or knurled configuration. The invention also provides an electrical cable having such a connector mounted thereon, making secure electrical connection with the conductor thereof, for example of copper or aluminium, which may be stranded. The invention also provides a method of making an electrical connection to an electrical cable wherein a conductor of the cable is exposed and a connector of the invention is mounted thereon. One embodiment of the present invention will now be described, by way of an example, with reference to the accompanying drawings, in which: Figure 1 is a side view of an electric cable connector; Figure 2 is an end view of the connector showing its inner surface; and Figure 3 is a view of the connector of Figures 1 and 2 mounted so as to terminate the stranded conductor of an electrical cable. Referring to the Figures, an electric cable connector 10 is formed from a copper tape of width 4.7 mm and thickness 0.7 mm that is formed into a helix of minimum inner diameter 6.25 millimetres to a maximum inner diameter of 9.0 millimetres, and of overall length 26.7 millimetres. The turns of the connector 10 substantially abut one another, and over a length of 24mm along a first portion 12 are of substantially constant diameter, before providing a turn 14 of intermediate diameter, and a final turn 16 at the other end of the connector 10 of larger diameter. The inner surface 18 of the connector 10 is contoured so as to provide a mesh-like configuration along its entire length. Figure 3 shows the connector 10 having been screwed onto the exposed stranded conductors 20 of a cable 22. It will be understood that the outer diameter of the bundle of stranded conductor 20 is greater than the largest inner diameter of the connector 10, and that the connector 10 has been screwed over the free end of the conductors 20, with its largest turn 16 leading. The resilience of the helical connector 10 is such that by screwing the connector 10, turn 16 foremost, forcing it to expand over the end of the bundle of conductors 20, the roughened inner surface 18 of the connector 10 abrades the outer surfaces of the strands 20, thus removing any oxide film thereon and ensuring good electrical contact between the connector 10 and the conductors 20 of the cable 22. The connector of the present invention is suitable for cables up to 16mm and current capacity of less than 100 amps, which may contain solid conductors, and also on larger cables, which may be formed from stranded conductors, up to 25mm2, and even 35mm2, carrying current up to 140 amps, for example. The connector finds particular application, for example, in terminating aluminium or copper conductors from 2.5mm2 to 35mm2 for use with an electrical distribution busbar rated at 140 amps, or conductors from 2.5mm2 to 50mm2 for 200 amp rated busbars. Such busbars may contain ten positions for electrical contact, providing for connection from a single supply cable to nine taps. Alternatively, if the ten positions are arranged in two groupings of five, then four taps are available for each of two points of supply. WE CLAIM: 1. An electric cable connector comprising a metal tape that is wound so as to form a radially-resilient helix characterized in that at least part of the inner surface of said tape is rough and said helix is of a size and shape suitable for use on power cables having conductor cross-sectional area greater than 10 mm2. 2. A cable connector as claimed in claim 1, wherein the helix is tapered. 3. A cable connector as claimed in claim 2, wherein the tapering of the helix is stepped. 4. A cable connector as claimed in claim 2 or 3, wherein the tapering of the helix is continuous along at least part of its length. 5. A cable connector as claimed in any one of claims 1 to 4, wherein the inner surface of the metal tape comprises a mesh configuration. 6. A cable connector as claimed in any one of claims 1 to 4, wherein the inner surface of the metal tape is of knurled configuration. 7. An electrical cable having a connector as claimed in any one of the preceding claims mounted on an electrical conductor thereof, the conductor having cross-sectional area greater than 10 mm2. 8. A cable as claimed in claim 7 wherein the conductor thereof is of stranded configuration. 9. A cable as claimed in claim 7 or claim 8, wherein the connector is mounted at an end region of the conductor to provide a termination thereof. 10. A method of making an electrical connection to an electric cable, wherein an electrical conductor thereof is exposed, and a connector as claimed in any one of claims 1 to 6 is mounted thereon, the said conductor having cross-sectional area greater than 10 mm2. 11. A method as claimed in claim 10, wherein the connector is screwed onto an end region of the conductor, thereby to terminate the cable. 12. A method as claimed in claim 10 or 11, wherein the conductor is of stranded configuration.

Documents:

2334-delnp-2006-abstract.pdf

2334-DELNP-2006-Claims (31-12-2009).pdf

2334-DELNP-2006-Claims-(12-10-2010).pdf

2334-delnp-2006-claims.pdf

2334-DELNP-2006-Correspondence Others-(20-03-2013).pdf

2334-DELNP-2006-Correspondence-Others (31-12-2009).pdf

2334-DELNP-2006-Correspondence-Others-(11-09-2006).pdf

2334-DELNP-2006-Correspondence-Others-(12-10-2010).pdf

2334-DELNP-2006-Correspondence-Others-(13-09-2010).pdf

2334-DELNP-2006-Correspondence-Others-(17-07-2009).pdf

2334-delnp-2006-correspondence-others-1.pdf

2334-delnp-2006-corrrespondence-others.pdf

2334-delnp-2006-description (complete).pdf

2334-delnp-2006-drawings.pdf

2334-delnp-2006-form-1.pdf

2334-delnp-2006-form-13.pdf

2334-delnp-2006-form-18.pdf

2334-delnp-2006-form-2.pdf

2334-DELNP-2006-Form-3-(13-09-2010).pdf

2334-DELNP-2006-Form-3-(17-07-2009).pdf

2334-delnp-2006-form-3.pdf

2334-delnp-2006-form-5.pdf

2334-DELNP-2006-GPA-(11-09-2006).pdf

2334-delnp-2006-pct-210.pdf

2334-delnp-2006-pct-304.pdf

2334-DELNP-2006-Petition-137-(20-03-2013).pdf

abstract.jpg