NZ196118A - Cable with conductive shield of woven tape - Google Patents

Description

TRUE COPY Prso;vfy-We6) Con:-~A2lo Cjjocl'iceticrs Filed: 4V. ic£«r%* Date: P.O. Jc:.I PJo: .£k°.

P.U. new_zealand 26 JAN 1981 the patents act s 1953 ' ; ;;c RECHf'/cD- -.r COMPLETE SPECIFICATION "SHIELDED CABLE" WE, INTERNATIONAL STANDARD ELECTRIC CORPORATION, a Corporation of the State of Delaware, United States of America, of 320 Park Avenue, New York 22, New York, United States of America, 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 a cable comprising an outer sheath enclosing at least one insulated conductor having disposed thereabout a conductive shield.

A known cable of the abovementioned type has a conductive shield in the form of an aluminium or copper foil. However, this type of shield renders the cable unsuitable for some purposes as this cable is somewhat inflexible. Another known cable has a shield in the form of a braided wire envelope which is applied over the insulated conductors by means of a braiding machine. The lastmentioned known cable is flexible but the application of the braided envelope renders the fabrication of the cable relatively expensive.

It is an object of the present invention to provide a relatively inexpensive shielded cable which is flexible.

Accordingly, there is provided a cable comprising an outer sheath enclosing at least one insulated conductor having disposed thereabout a conductive shield, wherein the said shield comprises a tape formed of interlaced filamentary conductive material.

Preferably, the tape comprises braided wire. By manufacturing the braided wire shield in the form of a tape, the cost of the cable is reduced in that the tape can be prefabricated on a separate braiding machine. Only a few standard tape widths need be produced which can be adopted to cables of various diameters. The tape can be advantageously applied t 96 1 1 contemporaneously with the cable sheath with the aid of a forming trumpet.

Preferably, a plastic coating may be applied to one side "of the braided tape.

In a further embodiment, the tape is prefabricated in the form of a woven tape having wire warp and weft. Unlike the braided tape the width of the woven tape need not be standardised and can be lapped helically about the insulated conduc-tor/s. If the cable includes a protective wrapping about the 10 insulated conductor/s, the woven tape can be applied thereabout contemporaneously with the application of the wrapping.

An embodiment of the invention will now be described in more detail with reference to the accompanying drawings, in which: Fig. 1 shows one end of a cable provided with a braided tape ; Fig. 2 shows how a plastic film is joined to the braided tape by heat sealing, and Fig. 3 shows one end of a cable provided with a woven, tape. 20 Fig. 1 shows one end of a cable 1, from which the outer sheath 2 has been removed and in which the shield is a braided tape 3. For clarity, the braided tape 3 is shown partly unfolded. The braided tape 3 encloses a cable core 4, which contains at least one conductor and may be protected by a wrap, 25 The cable core 4 and the outer sheath 2 may be of any converi- tional construction.

When being applied to the cable core 4 by means of a forming "trumpet", the braided tape 3, consisting of bare metallic wires, is formed into a tube in such a way that the latter is lapped longitudinally over, and clings to the cable core. The overlap ensures the necessary contact between the contiguous parts. The outer sheath 2 can be applied over the braided tape 3 immediately thereafter and holds the latter in place.

The braided tape 3 can be prefabricated on a braiding machine in given widths using metallic wires as are commonly employed for braids. . The network structure and the density of cloth can be chosen with regard to the intended application, and they are fixed by bonding a plastic film 5 to one side of the tape 3 (Fig. 2). Advantageously, use is made of a heat-sealable film which can be applied to the braided tape 3 by means of a hot roll 6. On one side, the film 5 must leave uncovered such an edge that contact is made between metallic surfaces with any overlap that may be chosen later. The braided tape 3 is fed into the braid-forming "trumpet" in such a way that the film 5 is on the outside.

Fig. 3 shows one end of a cable 7 from which the outer sheatl 8 has been removed, and in which the shield is a woven tape 9 of copper. This woven tape is lapped helically over the cable core 10 covered with plastic film.

Claims (9)

What we claim is:

1. A cable comprising an outer sheath enclosing at least one insulated conductor having disposed thereabout a conductive shield, wherein the said shield comprises a tape formed of interlaced filamentary conductive material.

2. A cable as claimed in claim 1, wherein the said shield comprises a tape formed of braided filamentary conductive material.

3. A cable as claimed in claim 1, wherein the said shield comprises a tape formed of woven filamentary conductive material.

4. A cable as claimed in any one of the preceding claims, wherein the said tape includes a plastics coating bonded to portion of one side thereof and arranged such that a longitudinal edge of said one side remains uncovered by the said plastics coating.

5. A cable as claimed in claim 4, wherein the said plastics coated shield is lapped longitudinally about the insulated conductor/s and arranged such that the said shield interposed between the plastics coating and the insulated conductor/s.

6. A cable as claimed in any one of the preceding claims, wherein the said tape is lapped helically about the insulated conductor/s.

7. A cable as claimed in any one of the preceding claims, wherein a protective wrapping is interposed between the insulated i 9 6 f g conductor/s and the shield.

8. A cable as claimed in any one of the preceding claims, wherein the said filamentary conductive material is copper wire.

9. A cable substantially as herein described with reference to Figs. 1-3 of the accompanying drawings. INTERNATIONAL STANDARD ELECTRIC CORPORATION P.M. Conrick -Authorized Agent 5/1/1053 ;si .. f V