United States Patent 19
`Simons et al.
`
`[11]
`(45)
`
`3,911,200
`Oct. 7, 1975
`
`(75
`
`54 ELECTRICAL CABLE HOUSING
`ASSEMBLIES
`Inventors: Herbert D. Simons, Long Valley,
`N.J.; Frank E. Timmons, Richmond,
`Ind.
`73) Assignee: Sun Chemical Corporation, New
`York, N.Y.
`
`Aug. 20, 1973
`22 Filed:
`21 Appl. No.: 389,894
`P
`Related U.S. Application Data
`62 Division of Ser. No. 323,950, Jan. 15, 1973.
`
`2,852,423
`3,051,771
`3,622,683
`3,634,800
`
`9/1958 Bassett, Jr......................... 174/36 X
`8/1962 Lee....................................... 174/36
`l l/1971
`Roberts et al........................ 174/36
`l/1972 Fisher............................. 174/ 19 R
`
`FOREIGN PATENTS OR APPLICATIONS
`356,899
`9, 1931
`United Kingdom.................. 174/36
`203,527
`6/1939 Switzerland..............
`... I 74/36
`50,273
`2/1932 Norway................................. 174/36
`448,551
`4/1969 Japan.............................. 174/ 1 19 R
`
`Primary Examiner-Arthur T. Grimley
`Attorney, Agent, or Firm-Cynthia Berlow
`
`57
`
`ABSTRACT
`
`52 U.S. Cl..................... 174/36; 174/72 R; 174/95
`(51) Int. Cl.'............................................ H01B 7/34
`A cable housing assembly for carrying a plurality of
`(58) Field of Search.... 29/624, 232; 156/47, 51-54,
`conductors comprises a longitudinal multifinned
`156/160, 163, 164, 196, 204, 213, 221, 222,
`shielding tape wherein each fin comprises a thin elon
`226, 227, 250, 258, 264, 265; 161/99, 165,
`gated flexible foil of material having relatively low
`167, 213-219, 221, 222; 138/11 1, 1 15, 1 16,
`electrical resistance characteristics and having each
`117; 174/70 R, 72, 68 C, 117 R, 17 F, 117
`FF, 119 C, 36, 27, 34, 35 R, 126 CP surface thereof bonded to and coextensive with a thin
`elongated flexible film of material having relatively
`high electrical resistance insulation characteristics.
`3 Clai
`12
`ing Fi
`laims, 12 Drawing Figures
`
`(56)
`
`2,318,367
`
`References Cited
`UNITED STATES PATENTS
`5/1943 Brigg............................... 174/119 R
`
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`U.S. Patent — oct. 7,1975
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`Sheet 1 of 2
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`3,911,200
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`U.S. Patent — oct. 7,1975 Sheet 2 of 2
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`U.S. Patent — oct. 7,1975 Sheet 2 of 2
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`3,911,200
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`1.
`ELECTRICAL CABLE HOUSING ASSEMBLES
`
`3,911,200
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`15
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`2
`FIG. 5 is a sectional view of an embodiment of a
`shielding tape showing the folded laminate of FIG. 4
`with a strip of plastic film over the fold gap.
`F.G. 6 is a cross-sectional view of an embodiment of
`a shielding tape showing two folded laminates of FIG.
`1 with a plastic film on each face.
`FIG. 7 is a cross-sectional view of the structure of
`FIG. 6 wherein the folded laminates of FIG.
`have
`opened to form four compartments.
`O
`FIGS. 8 and 9 are cross-sectional views of embodi
`ments of a shielding tape showing a plurality of folded
`laminates of FIG. 1 of equal lengths with a plastic film
`on the top and the bottom faces.
`FIG. 10 is a cross-sectional view of an embodiment
`of a shielding tape showing a plurality of folded lami
`nates of FIG. 1 of unequal lengths with a plastic film on
`the top and the bottom faces.
`FIG. 11 is a cross-sectional view of a cable structure
`showing the cable jacket and four longitudinal cable
`compartments of equal size.
`Flg. 12 is a cross-sectional view of a cable structure
`showing the cable jacket and six longitudinal cable
`compartments of unequal size.
`Now referring to the figures, FIG. 1 illustrates the
`laminate of a metal foil 10 and a plastic film 11 which
`is the basis of the shielding tapes of this invention. The
`metal foil 10 may be any conductive metal normally
`used in the cable industry such as for example alumi
`num, copper, tinned copper, steel, silver, or the like.
`The plastic film 11 may be any suitable insulation
`material such as for example a polyolefin, e.g., poly
`ethylene or polypropylene; polyethylene terephthalate
`(Mylar); tetrafluoroethylene polymer (Teflon); polyvi
`nyl chloride; polystyrene; polyvinylidene fluoride; a
`polyamide; a polycarbonate; or the like.
`The adhesive interface 13 may be any suitable adhe
`sive such as for example a polyolefin, a polyester, poly
`vinyl chloride, or the like.
`Shown in FIG. 2 is essentially the same laminate as
`shown in FIG. 1 but with a heat-fusible coating (12) on
`the metal foil. The coating may be any suitable material
`such as for example polyethylene, polyester, polyvinyl
`chloride, or the like.
`The simplest embodiment of this invention is shown
`in FIG. 3. This structure is formed by the steps of (1)
`making a laminate of a metal foil 10 half the thickness
`required for shielding and a plastic film 11 of the thick
`ness required for insulating the finished tape, (2) apply
`ing a heat-fusible coating 12 to the metal foil, (3) cut
`ting the laminate to twice the width required, and (4)
`folding the laminate upon itself with the coated metal
`foil on the inside, forming a shielding tape with one
`folded edge insulated and the core heat-sealed to block
`moisture.
`FIG. 4 shows a second embodiment in which the lam
`inate is folded upon itself from both ends, the edges
`being butted at fold gap 14 to form a tape that is water
`tight and thus protected from corrosion, and both
`edges are insulated.
`In FIG. 5the fold gap 14 is shown covered with a sep
`arate piece of insulating film 5 which is laminated
`thereto by means of any suitable adhesive. The insulat
`ing film 15 may be the same as film 11 or different. This
`further protects the foil edges from corrosion and com
`pletely encapsulates the conductive foil in an insulating
`film.
`
`This application is a division of copending applica
`tion Ser. No. 323,950 (filed Jan. 15, 1973).
`This invention relates to multiconductor cables in
`general and more particularly relates to means for
`shielding certain of the conductors of a multiconductor
`cable from other conductors of the cable. It is an in
`provement over the shielding means disclosed in U.S.
`Pat. No. 3,622,683 issued Nov. 23, 1971, to W. L. Ro
`berts et al. for Telephone Cable with Improved Cross
`talk Properties.
`As communications systems grow more complex, it
`becomes increasingly important to be able to transmit
`an increasing number of currents within the same ca
`ble, for example the transmission of telephone signals,
`video messages, and two-way data transmission. It is es
`sential that the conductors be isolated electrically and
`physically from each other within the cable. It is also
`essential that the overall cable structure be compact,
`lightweight, and flexible and that the conductors
`therein be kept free from moisture.
`In the communications industry it is common prac
`tice to use a floating or grounded shield of aluminum
`25
`or copper between several sections of cable. This shield
`is generally by not necessarily totally sealed and mois
`tureproof within an enclosure of plastic insulating film
`in order to keep the shield free from electrical contact
`with adjacent insulated conductors and free from dam
`30
`age and/or corrosion by moisture which may enter the
`cable and track the length of the shield.
`The use of one tape to shield one conductor or a pair
`or a group of conductors from another conductor or
`pair or group of conductors, permitting simultaneous
`transmission of two separate currents of the same fre
`quency within the same cable, is known, as in for exam
`ple U.S. Pat. Nos. 3,032,604 and 3,622,683.
`In accordance with the instant invention there is pro
`vided a longitudinal shielding tape having a wide vari
`40
`ety of embodiments whereby the speed of manufactur
`ing the cable and the shielding efficiency are increased,
`the volume and space within the cable are better uti
`lized and foil corrosion is minimized.
`In general the encapsulated film/foil laminated longi
`tudinal multiconductor cable electrostatic shielding
`tapes of this invention are prepared by the steps of (A)
`forming a strip of a laminate of metal foil and plastic
`film bonded together by any suitable and conventional
`means with any suitable adhesive, such as a heat-fusible
`resin, a solvent-release rubber, or a solvent-release
`plastic base adhesive, and (B) folding the strip (A)
`upon itself.
`The invention will be more fully understood from the
`following description of the accompanying drawings, in
`which:
`FIG. 1 is a cross-sectional view of a laminate of plas
`tic film and metal foil.
`FIG. 2 is a cross-sectional view of a laminate of plas
`tic film and metal foil with a heat-fusible coating on the
`metal foil.
`FIG. 3 is a cross-sectional view of an embodiment of
`a shielding tape showing the laminate of FIG. 2 folded
`upon itself with the plastic film on the outside.
`65
`FIG. 4 is a cross-sectional view of an embodiment of
`a shielding tape showing the laminate of FIG. 2 folded
`upon itself from both edges.
`
`45
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`SO
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`O
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`15
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`3,911,200
`3
`4.
`Shielding tape systems for longitudinal parallel
`By shielding a conductor, pairs of conductors, or
`shielding of insulated wires and wire groups in com
`groups of conductors as described above, maximum
`partmentalized multiconductor cables are also within
`utilization of space and material weight is obtained;
`the scope of this invention. These are made by the steps
`cable manufacturing speed is increased; the dual-foil
`of (1). laminating by any known means a metal foil 10
`encapsulation in several of the embodiments results in
`and a plastic film 11, as in FIG. 1, (2) slitting the lami
`increased shielding effectiveness, because of foil
`nate to any desired width, (3) slitting heat-fusible
`interface reflectance; and foil corrosion is minimized in
`coated plastic film 16 to the same width as the laminate
`non-filled cable because moisture will not so readily
`in step (2), (4) folding the laminate from step (2) in
`reach the conductive foil.
`half lengthwise plastic-to-plastic, (5) laying two folded
`Although there have been described preferred em
`laminate tapes from step (4) fold-to-fold and (6) lami
`bodiments of this novel invention, many variations and
`nating to each of the resulting faces a heat-fusible
`modifications will now be apparent to those skilled in
`coated plastic film from step (3) in any known and con
`the art. This invention, therefore, is to be limited not by
`venient manner, as in FIG. 6. The plastic film 16 may
`the specific disclosure herein but only by the appended
`be the same as film 11 or different.
`claims.
`The shielding tape from step (5) above is inserted
`What is claimed is:
`into the ultimate cable by any suitable means, such as
`1. A cable housing assembly for carrying a plurality .
`by feeding the tape from a pad directly into the cabler
`of cables comprising a jacket of flexible insulating ma
`with the insulated single conductors or insulated
`terial enclosing a shielding tape comprising in combina
`groups. The shielded, compartmentalized multiconduc
`tion (a) a thin elongated flexible film of material having
`tor core can then be further processed, i.e., jacketed,
`relatively high electrical resistance insulation charac
`sheathed, etc. As the tape is fed into the cabler it opens
`teristics and (b) a thin elongated flexible foil of mate
`as in FIG. 7 to a system having four fins forming four
`rial having relatively low electrical resistance charac
`longitudinal parallel shielding compartments, each ba
`teristics and having one surface thereof bonded to one
`sically pie-shaped or triangular in shape and having the
`25
`surface of said film (a) and being coextensive there
`same cross-sectional areas.
`with, said shielding tape being folded along a longitudi
`It is within the scope of this invention to vary the type
`nally extending crease, thereby to be doubled in thick
`and gauge of the film and/or of the foil. It is also within
`ness, said thin foil (b) having a thin layer of bonding
`the scope of this invention to provide longitudinal
`material disposed on the surface thereof which is oppo
`multicompartmentalized shielding tapes having more
`site to its said one surface bonded to said film (a),
`than four fins and parallel compartments by varying the
`whereby a foil-to-foil connection is made by said thin
`number of the folded tapes as in FIGS. 8 and 9 and/or
`layer of bonding material.
`having different cross-sectional areas by varying the
`2. A cable housing assembly for carrying a plurality
`size of the folded tapes as in FIG. 10; in each of the sys
`of cables comprising a jacket of flexible insulating ma
`tems illustrated in FIGS. 8, 9, and 10, the folded tapes
`terial enclosing a shielding tape comprising in combina
`open at each plastic-to-plastic interface, as shown in
`tion (1) a plurality of folded laminates, each compris
`FIG. 7. In such multi layers of folded tapes, the faces
`ing (a) a thin elongated flexible film of material having
`of the tapes are laminated metal-to-metal with any suit
`relatively high electrical resistance insulation charac
`able adhesive 17, such as for example solvent-release
`teristics and (b) a thin elongated flexible foil of mate
`polyethylene, rubber, polyester, polyvinyl chloride, or
`40
`rial having relatively low electrical resistance charac
`the like.
`teristics and having one surface thereof bonded to one
`FIG: 11 illustrates an electrical cable comprising an
`surface of said film (a) and being coextensive there
`outer jacket or sheath 18 made of an insulating mate
`with, each said laminate being folded along a longitudi
`rial such as plastic, rubber, or the like, and a four
`nally extending crease, thereby to be doubled in thick
`compartment shielding tape 19, for example, as shown
`45
`ness and bringing the surface of said film (a) which is
`in FIGS. 6 and 7.
`opposite its said one surface into contact with itself,
`FIG. 12 illustrates an electrical cable comprising an
`whereby the surface of said foil (b) forms outer oppo
`outer jacket or sheath 18 and a six-compartment
`site surfaces of said folded laminate and (2) insulation
`shielding tape. 19, for example, as shown in FIG. 10.
`film layers bonded to and coextensive with both the top
`The shielding tapes described herein may be spliced
`50
`and the bottom foil surfaces of said plurality of folded
`in any suitable manner as long as there is shielding con
`laminates arranged fold-to-fold and foil-to-foil.
`tinuity; thus there may be used, for example, an electri
`cal continuity penetration clamp to join the conducting
`3. The cable assembly of claim 1 wherein the film is
`material and a plastic film to join the insulating mate
`a plastic and the foil is a metal.
`rial.
`k
`ck.
`k.
`k
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`sk
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`65
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