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Publication numberUS3728474 A
Publication typeGrant
Publication dateApr 17, 1973
Filing dateNov 15, 1971
Priority dateNov 15, 1971
Publication numberUS 3728474 A, US 3728474A, US-A-3728474, US3728474 A, US3728474A
InventorsArnaudin E
Original AssigneeAnaconda Wire & Cable Co
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Shielded power cable
US 3728474 A
Abstract
Electric power cables with semiconducting jackets have stranded or bunched drain conductors embedded in the jackets, in line with the cable axis.
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Description  (OCR text may contain errors)

United States Patent 1 Arnaudin, Jr.

SHIELDED POWER CABLE Edwin H. Amaudin, Jr., Eden, NC.

Anaconda Wire and Cable Company, New York, NY.

Filed: Nov. 15, 1971 Appl. No.: 199,064

Inventor:

Assignee:

US. Cl. ..l74/1l5, 174/105 SC, 174/120 SC References Cited UNITED STATES PATENTS Plate et 51 ..174 107 x [451 Apr. 17, 1973 3,115,542 12/1963 Palandri et al ..174/102 R 3,474,189 10/ 1969 Plate et a1 174/1 15 2,981,788 4/1961 Bunish ..174/l15 3,584,139 6/1971 Swanson ..174/l15 X 3,573,348 4/1969 Herrman ..174/113 R 3,324,233 6/1967 Bryant ...174/113 R X 3,351,706 11/1967 Gnen'e et al.. ..174/107 X 3,020,334 2/1962 Riley ..174/107 Primary Examiner-Bernard A. Gilheany Assistant Examiner-A. T. Grimley Attorney-Victor F. Volk [57] ABSTRACT Electric power cables with semiconducting jackets have stranded or bunched drain conductors embedded in the jackets, in line with the cable axis.

6 Claims, 4 Drawing Figures SHIELDED POWER CABLE BACKGROUND OF THE INVENTION In Plate et al. US Pat. No. 3,474,189 issued Oct. 2l, 1969 an electric power cable is described having a thick semiconducting polymeric jacket applied directly over the cable insulation and undulatory drain wires embedded in the jacket. These wires are not wrapped helically around the cable but lie on axes parallel to, i.e. in line with, the cable axis. The undulations increase the cable flexibility, since they prevent the wires in the outside arc of a bend in the cable from stretching or breaking. They do require special equipment, however, such, for example, as that described in Menasoff patent 3531962.

SUMMARY I have now found that a sufficiently flexible cable can be made with embedded drain wires that have been manufactured on conventional equipment such as stranders or, preferably, bunchers. Thus a cable of my invention comprises a conductor, a wall of insulation surrounding the conductor, a thick jacket of semiconducting polymeric material directly surrounding the wall of insulation and a plurality of drain conductors embedded in the jacket substantially in line with the cable axis. The conductors each comprises a plurality of wires and each of these wires is helically wound around at least one other wire within the same plurality forming that drain conductor. The drain conductors are preferably copper or aluminum or alloys of copper or aluminum and preferably comprise bunched strands in which case the diameters of the wires are preferably 0.005-0.0l inch for copper and 0.007-0.012 inch for aluminum. Advantageously the bunched strands have been flattened to an oval section to cover a greater area of the cable surface, and reduce the thickness of jacket necessary to contain them.

BRIEF DESCRIPTION OF THE DRAWING:

FIG. 1 shows a pictorial view, partially cut away, of one embodiment ofa cable of my invention.

FIG. 2 shows a pictorial view, partially cut away, of another embodiment of the cable of my invention.

FIG. 3 shows a pictorial view, partially cut away, of still another embodiment of the cable of my invention.

FIG. 4 shows a pictorial view of still another embodiment of the cable of my invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT Referring to the Figures, my cable, indicated generally in FIG. 1 by the numeral 10, comprises a conductor 11, a layer of insulation 12 and a semiconducting jacket 13 none of which is, of itself, novel and which are adequately described in the aforementioned US. Pat. No. 3,474,189, the disclosures of which, where relevant, are included in the present description. A novel feature of the present invention resides, however, in a drain wire 14 comprising bunched copper strand. Bunched strand" is a term well established in the cable arts and corresponds to the term bunchedstranded conductor defined in ASTM Designation B 354-70a. Bunched strands are manufactured by machines known as bunchers" or bunch-stranders" TABLE 1 Size of Minimum number of wires in conductor Size of wires, Awg Conductor AwgNo. No.28 No.30 No.32 No.34 No.36 No.3s' No.40

l6 I6 26 41 65 I04 I8 I0 I6 26 M 65 I04 I65 20 7 I0 16 26 41 65 I04 A feature of bunched strands that adds to their utility for my invention resides in the absence of any straight central wire like those that are found in concentric stranded conductors. Such a central strand would be stretched, possibly to the breaking point, upon bending the cable 10. The fact that bunchers are available in most cable plants or can be purchased from commercial sources without recourse to special designing and fabricating provides an advantage to the use of bunched strand in my present invention. To manufacture my cable 10 the bunched strands 14 are paid through the extrusion die during the extrusion of the jacket 13 and the extrusion head can be adjusted or designed to embed the conductor 14 tangent to the outer surface of the jacket as in FIG. 1 or well below the surface as illustrated by a cable 16 in FIG. 4. The bunched strands may also be embedded so as to project from the surface and expose a portion of the metal as exemplified for an elastic cored strand 17, to be further described below, in FIG. 3. Because of its higher conductivity and resistance'to moisture-induced corrosion I prefer copper or copper alloys for the conductors 14 and 17, but where corrosion presents no problem aluminum or aluminum alloys of high electrical conductivity may also be used.

FIG. 2 illustrates an embodiment of my invention wherein a bunched drain conductor 18 has been fiattened, by passage through rolls, to an oval shape, before being embedded in the cable jacket. This flattening has the advantage of affording a greater area of metallic shielding to the cable surface and a greater area of contact between the metal of the conductors and the semiconducting jacket composition. It also allows a reduction in the thickness of jacket necessary to embed the drain conductors. Reduction in the radial dimension of bunched conductors to as little as 30 percent of their original diameter is feasible for copper conductors and as little as 50 percent for aluminum conductors although, in the case of aluminum alloys, that do not become embrittled during the operation of rolling, somewhat greater reductions are possible.

If a group of parallel wires are wrapped as a unit around a core that is later withdrawn from the wrapped strand, each of the wires will have been wrapped around all of the others, unless, during the wrapping operation the group of wires was back-twisted around its own axis as is done during planetary stranding. This wrapping of the parallel wires around themselves is readily demonstrated by the impossibility of lifting one of the wires from the strand after the core has been withdrawn. In a bunched strand each of the wires wraps around at least some of the remaining wires in the bunch and so acquires an additional length that adds flexibility. In the embodiment of FIG. 3 the wires are not bunch stranded but are evenly wound around a flexible core 19 which may preferably comprise an extruded filament of the same semiconducting stock as the jacket 13 but may comprise other filaments such as polycarbonate and polyimide that will not melt or disintegrate at the extrusion temperatures of a particular jacket stock.

The foregoing description has been exemplary rather than definitive of my invention for which I desire an award of Letters Patent as defined in the appended claims.

Iclaim:

1. An electric power cable comprising:

A. a conductor,

B. a wall of insulation surrounding said conductor,

C. a thick jacket of semiconducting polymeric material directly surrounding said wall of insulation, and

D. a plurality of bunch stranded drain conductors embedded in said jacket substantially in line with the axis of said cable,

B. said drain conductors each comprising a plurality of wires, each of the wires within one of said plurality of wires being helically wound around at least one other wire within said plurality of wires.

2. The cable of claim 1 wherein said wires are selected from the group consisting of copper and copper alloys.

3. The cable of claim 1 wherein said wires are selected from the group consisting of aluminum and aluminum alloys.

4. The cable of claim 1 wherein said bunch-stranded drain conductors are flattened to an oval shape 5. The cable of claim 2 wherein said bunch-stranded drain conductors are flattened to an oval shape.

6. The cable of claim 3 wherein said bunch-stranded drain conductors are flattened to an oval shape.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2981788 *Dec 3, 1958Apr 25, 1961Anaconda Wire & Cable CoPower cables
US3020334 *Oct 1, 1959Feb 6, 1962Bell Telephone Labor IncElectrical cable
US3115542 *May 2, 1961Dec 24, 1963PirelliSubmarine electric cables
US3324233 *Apr 8, 1965Jun 6, 1967Amphenol CorpCable complex employing strand twist reversal to absorb longitudinal expansion
US3351706 *Mar 18, 1965Nov 7, 1967Simplex Wire & Cable CoSpaced helically wound cable
US3474189 *Dec 22, 1967Oct 21, 1969Anaconda Wire & Cable CoElectric power cable
US3571613 *May 20, 1970Mar 23, 1971Anaconda Wire & Cable CoCable system
US3573348 *Apr 25, 1969Apr 6, 1971Herrmann Edward MNeutrally buoyant vertical underwater cable
US3584139 *Dec 27, 1968Jun 8, 1971Bell Telephone Labor IncTorque-balanced communications cable
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3896261 *Apr 15, 1974Jul 22, 1975Belden CorpCoaxial cable with an undulated drain wire
US4081602 *Mar 3, 1976Mar 28, 1978Canada Wire And Cable LimitedSelf-supporting cable
US4570477 *Jan 27, 1984Feb 18, 1986Junkosha Company Ltd.Leak detecting cable
US4710594 *Jun 23, 1986Dec 1, 1987Northern Telecom LimitedTelecommunications cable
US5331606 *May 29, 1992Jul 19, 1994Western Atlas International, Inc.Static dissipating data cable and seismic apparatus
US5807447 *Oct 16, 1996Sep 15, 1998Hendrix Wire & Cable, Inc.Neutral conductor grounding system
US6046408 *Jun 26, 1998Apr 4, 2000Hendrix Wire & Cable, Inc.Neutral conductor grounding system
US20140102757 *Dec 20, 2013Apr 17, 2014The Boeing CompanyLightning Protection for Spaced Electrical Bundles
Classifications
U.S. Classification174/115, 174/120.0SC, 174/105.0SC
International ClassificationH01B9/00, H01B9/02
Cooperative ClassificationH01B9/026
European ClassificationH01B9/02F
Legal Events
DateCodeEventDescription
Feb 25, 1985ASAssignment
Owner name: ANACONDA ACQUISITION CO., 17 SQUADRON BOULEVARD, N
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:ERICSSON, INC., A CORP OF DE;REEL/FRAME:004364/0732
Effective date: 19850215
Feb 9, 1981ASAssignment
Owner name: ANACONDA-ERICSSON INC., A CORP. OF DE
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:ANACONDA COMPANY, THE A CORP. OF DE;REEL/FRAME:003846/0822
Effective date: 19800728
Owner name: ANACONDA-ERICSSON INC., A CORP. OF,DELAWARE
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:ANACONDA COMPANY, THE A CORP. OF DE;REEL/FRAME:3846/822
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:ANACONDA COMPANY, THE A CORP. OF DE;REEL/FRAME:003846/0822
Owner name: ANACONDA-ERICSSON INC., A CORP. OF, DELAWARE