0
`
`UI
`
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`"'" 0
`.. ...,
`..,
`........
`U1
`
`Consornrnn110, 1
`et CorµrJrar.oni; Cnmi<f.t
`
`Consumer ,ir1<1
`Corporate All a1rs Can,1d1.1
`
`Bureau des brevets
`
`Pntent Office
`
`Onawa. Canarla
`K1 A OC9
`
`(21) (Al)
`
`2,058,046
`
`(22)
`
`( 4 3)
`
`1991/12/18
`
`1992/08/22
`
`5
`(51) INTL.CL. H0lB-011/04
`
`(19) (CA) APPLICATION FOR CANADIAN PATENT (12)
`
`(54) Manufacture of Telecommunications Cable
`
`(72) Tessier, Ronald - Canada ;
`Mcgettigan, Philip A.
`- Canada ;
`Kish, Paul P.
`- Canada
`
`(73) Same as inventor
`
`(30)
`
`(US) 658,727 1991/02/21
`
`(57) 7 Claims
`
`Notice : The specification contained herein as filed
`
`Canada
`
`CCA 3254 (10·89) 41
`
`

`

`2058046
`
`9
`
`MANUFACTURE OF TELECOMMUNICATIONS CABLE
`
`Abstract of the Disclosure
`
`A telecommunications cable in which pairs of
`twisted together conductors are spaced apart to minimize
`capacitance unbalance and cross-talk. A central core
`member may be provided with the conductor pairs extending
`around the core member which may have spokes to separate
`the conductor pairs. Alternatively, the cable jacket has
`inwardly directed spacers which separate the conductor pins
`and hold them in recesses defined by the jacket ·.
`
`

`

`2058046
`
`1
`
`MANUFACTURE OF TELECOMMUNICATIONS CABLE
`This invention relates to telecommunications
`
`cable.
`
`20
`
`Telecommunications cable is normally constructed
`s with a core comprising one or more core units, each having
`a multiplicity of twisted units of conductors, each unit
`conventionally being a twisted pair of conductors. A core
`may be formed as a single core unit of twisted pairs . Care
`is taken, so far as is practicable, to ensure that pairs of
`10 equal or similar twist lays are separated from each other
`by other pairs. The reason for this arrangement is an
`attempt to maximize the communications performance of the
`cable, e.g. to lessen pair-to-pair capacitance unbalance,
`to reduce cross-talk between pairs, and to lower the co-
`15 efficient of deviation of mutual capacitance of pairs in
`the cable. To reduce the pair-to-pair capacitance un(cid:173)
`balance and to reduce cross-talk, suggestions have been
`made to move the conductor pairs relative to one another as
`they progress towards a stranding machine for stranding
`them into a core unit so that in the finished core unit,
`the conductor pairs change in relative positions and dis(cid:173)
`tances apart.
`In a suggested method for changing the
`relative positions of conductor pairs as they move towards
`the stranding machine, the conductor pairs enter a guide
`arrangement which comprises a system of horizontal guides
`movable horizontally and located in vertical tiered
`fashion. This method was first suggested bys. Norblad of
`Telefonaktiebolaget L . M. Ericsson, in a paper entitled
`"Capacitance Unbalance Telecommunications Networks" read
`30 before the International Wire and Cable Symposium in 1971.
`As a result of the use of this method, the conductor pairs
`obviously change positions and distances apart in the
`finished core and perhaps in a random manner.
`The present invention seeks to provide an eJ.ectri-
`35 cal telecommunications cable construction in which pair-to(cid:173)
`pair capacitance unbalance and cross-talk is minimized in
`some other manner.
`
`2s
`
`

`

`2058046
`
`2
`
`15
`
`Accordingly, the present invention provides an
`electrical telecommunications cable comprising a plurality
`of pairs of individually insulated conductors, the con(cid:173)
`ductors in each pair twisted together, and spacer means
`5 holding the pairs of conductors spaced apart.
`The spacer means may be disposed along the axis of
`the cable or may be provided by inwardly extending pro(cid:173)
`jections of a jacket which surrounds the cable pairs .
`When the spacer means is disposed along the axis
`10 of the cable, it may be a central core member of substan(cid:173)
`tially circular shape. Alternatively, the central core
`member may be provided with radially outwardly extending
`projections which are spaced apart circumferentially of the
`core member and define recess regions between the pro-
`jections. Each pair of conductors is disposed in an indi(cid:173)
`vidual recess region and is separated from other pairs by
`the projections.
`In a further alternative arrangement, the
`spacer means comprises a plurality of spokes diverging
`radially outwards from the center to define recess regions
`for the conductors between the spokes.
`Where the spacing means is provided by the pro(cid:173)
`jections extending inwardly from the jacket, then these
`projections are spaced circumferentially around the jacket
`to provide spacers and the pairs of conductors are
`25 separated from one another by the projections.
`In a
`practical manner of providing such a structure, the pro(cid:173)
`jections converge towards a common center and have spaced
`apart inner ends disposed outwardly of the center.
`Chambers are thus formed within the jacket and are defined
`30 partly by a circumferentially extending portion of the
`jacket and two projections positioned one at each end of
`the circumferentially extending portion.
`Embodiments of the invention will now be
`described, by way of example, with reference to the accom-
`35 panying drawings, in which: -
`Figures 1 to 6 are cross-sectional views through
`six cables each of which forms an embodiment according to
`
`20
`
`

`

`205804G
`
`3
`
`s
`
`the present invention.
`In a first embodiment as shown by Figure 1, an
`electrical telecommunications cable 10 comprises a jacket
`12 of suitable polymeric material, the jacket surrounding
`four pairs 14 of individually insulated metal (i.e . copper)
`conductors 16. The conductors in each pair are twisted
`together in conventional manner.
`As may be seen from Figure 1, the four pairs 14 of
`conductors are spaced apart circumferentially of the cable
`10 by being disposed around a spacer means which is in the
`form of a central core member 18 of substantially circular
`cross-section . This spacer member is flexible, is capable
`of withstanding torsion, and is formed from a dielectric
`material. The pairs 14 of conductors 16 are stranded
`15 around the central core member 18 with the distances
`between the pairs around the core member maintained along
`the length of the cable. The spacing of the pairs mini(cid:173)
`mizes cross-talk between the pairs and in effect the volt(cid:173)
`age induced in the pairs is decreased. Dependent upon the
`20 performance requirements of the cable, the distances
`between the pairs can be determined for any particular AWG
`of conductor and mathematical modelling may be used to
`determine these required distances. Further, as may be
`seen from Figure 1, the distances between adjacent pairs
`25 are substantially equal so that the induced voltages
`between the pairs is substantially the same. Hence, a
`degree of design control is provided for maintaining the
`distances between the conductor pairs constant along the
`length of the cable and as these distances are substan-
`tially equal from one pair to another, cross-talk between
`adjacent pairs is carefully controlled.
`In other embodiments now to be described, features
`of the cable constructions which are similar to that of the
`first embodiment and/or to each other will bear the same
`reference numerals.
`In a second embodiment, as shown with reference to
`Figure 2, in a cable 20, the jacket 12 surrounds four pairs
`
`30
`
`35
`
`

`

`2058046
`
`4
`
`s
`
`20
`
`25
`
`14 of insulated conductors 16 which are held in controlled
`distances apart, as they extend in stranded condition along
`the cable, by a spacer means in the form of a central core
`member 20. This core member extends axially along the
`cable and is formed from a tensile dielectric material. It
`has a central mass 22 from which four radially outwardly
`extending projections 24 extend, the projections 24 being
`equally angularly displaced around the axis of the core
`member 20. The projections 24 are tapered as shown in
`10 Figure 2 with concave sides which merge from projection to
`projection to provide a smoothly curved surface to a recess
`region 26 extending between adjacent projections. Lying
`within each of the recesses 26 is an individual pair 14 of
`the conductors. The projections 24 and thus the recesses
`15 26 extend in helical fashion along the core member 20 to
`allow the pairs 14 to lie within the recesses in stranded
`fashion. As shown by Figure 2 the projections 24 only
`extend part way towards the inside surface of the jacket,
`but it must be understood that the projections could extend
`further towards the jacket dependent upon the degree of
`flexibility or stiffness required from the core member.
`In Figure 3 is shown a third embodiment of the
`invention. As shown by Figure 3 , a telecommunications cable
`30 has its jacket 12 again surrounding four circumferen-
`tially spaced pairs 14 of conductors 16. This structure is
`similar to that described in the second embodiment except
`that the central core member 20 of the second embodiment is
`replaced by a spacer means in the form of a body 32 formed
`by four helically extending spokes 34 which lie, in cross-
`section, at right angles to one another in cruciform
`fashion and extend outwardly from a common center as shown.
`The spokes have a constant thickness from end-to-end and
`form individual recess regions 36 between the spokes, these
`recess regions having straight convergent sides formed by
`sides of the spokes. The recess regions accommodate the
`pairs 14 of conductors, one pair to each of the recess
`regions.
`
`30
`
`35
`
`

`

`2058046
`
`5
`
`In a fourth embodiment as shown by Figure 4, a
`cable 40 is provided with four pairs 14 of insulated con(cid:173)
`ductors 16. The four pairs 14 are surrounded by a jacket
`42 which incorporates spacer means for holding the pairs of
`5 conductors in spaced apart positions. The spacer means is
`provided by a plurality (namely four) of inwardly extending
`helically extending projections 44 spaced apart circumferen(cid:173)
`tially around the jacket. These projections are integrally
`formed with the jacket during jacket extrusion and are
`10 equally angularly spaced apart around the axis of the
`jacket . The projections 44 are tapered radially to inner
`free ends 46 which are spaced outwardly from the axis of
`the jacket. This tapering is effected by concave surfaces
`which blend from one projection to another so as to define
`15 between adjacent projections recess regions 48 having
`smooth concave surfaces. The recess regions having open(cid:173)
`ings 50 facing inwardly towards the axis of the jacket.
`Each pair 14 of conductors is housed within an individual
`recess 48, as shown, so that the distances between adjacent
`20 pairs is substantially constant along the length of the
`cable and with the distances between the pairs being sub(cid:173)
`stantially equal as described for other embodiments above.
`In a fifth embodiment as shown by Figure 5 a cable
`52 has a jacket 54 also formed with radially inwardly
`extending and helically extending projections 56 of
`slightly different shape from those shown with regard to
`Figure 4.
`In the case of the fifth embodiment the pro(cid:173)
`jections 56 extend with parallel sides radially outwards
`from their free ends 58 for a certain distance and then
`each of the projections increases in thickness with
`diverging flat surface areas 60. The surface areas 60 of
`adjacent projections 56 are substantially parallel on each
`side of a recess region or chamber 62 defined between the
`surface areas 60 and also by the inside surface 64 of a
`35 circumferentially extending portion of the jacket . Each
`chamber 62, which opens in a radially inward direction as
`described for the fourth embodiment above, houses an indi-
`
`30
`
`25
`
`

`

`205804G
`
`6
`
`victual pair 14 of insulated conductors 16.
`In a sixth embodiment shown by Figure 6, a cable
`66 is of substantially the same structure as the cable 52.
`The cable 66 differs basically from cable 52 in that the
`s projections 56 of changing thickness are omitted.
`Instead,
`the cable 66 has spacer means formed by four radially
`inwardly extending spokes 68 of constant thickness formed
`integrally with the jacket. Radially inwardly extending
`recess regions or chambers 70 housing individual conductor
`10 pairs 14 are defined between opposite spoke surfaces and
`relatively long circumferentially extending portions 72 of
`jacket 14.
`In each of the embodiments described above, the
`pairs of conductors around the cable from pair-to-pair are
`15 maintained substantially equal distances apart with the
`distances between adjacent pairs maintained substantially
`constant along the length of the cable. This has the
`effect of minimizing cross-talk between pairs and per(cid:173)
`mitting closeness between some of the pairs such as to
`20 detract from this minimized cross-talk capability.
`
`

`

`2058046
`
`7
`
`WHAT IS CLAIMED IS:
`
`s
`
`10
`
`1 . An electrical telecommunications cable c(cid:173)
`omprising a plurality of pairs of individually insulated
`conductors, the conductors in each pair twisted together,
`and spacer means holding the pairs of conductors spaced
`apart.
`
`2. A cable according to claim 1 wherein the
`spacer means is disposed along the axis of the cable and
`the pairs of conductors extend helically around the spacer
`means in circumferentially spaced positions.
`
`15
`
`3. A cable according to claim 2 wherein the
`spacer means is a central core member of substantially
`circular shape.
`
`4. A cable according to claim 2 wherein the
`spacer means comprises a central core member provided with
`radially outwardly extending projections spaced apart
`circumferentially of the spacer means to define recess
`regions between the projections with each pair of con(cid:173)
`ductors disposed in an individual recess region and being
`separated by other pairs by the projections, the pro-
`jections extending helically along the core member.
`
`20
`
`25
`
`5. A cable according to claim 2 wherein the
`spacer means comprises a plurality of spokes diverging
`radially outwardly from a center to define recess regions
`30 between spokes, with each pair of conductors disposed in an
`individual recess region and being separated from other
`pairs by the spokes, the spokes extending helically along
`the cable.
`
`35
`
`6. A cable according to claim 1 wherein the pairs
`of conductors are surrounded by a cable jacket, the jacket
`formed with a plurality of inwardly extending projections
`
`

`

`2058 046
`
`8
`
`spaced apart circumferentially around the jacket to provide
`spacer means, the pairs of conductors separated from one
`another by the projections.
`
`5
`
`10
`
`7. A cable according to claim 6 wherein the
`projections converge towards a common center and have
`spaced apart inner ends disposed outwardly of the common
`center, and chambers are defined within the jacket , each
`chamber by a circumferentially extending portion of the
`jack et and two projections, one at each end of the cir-
`curnferentially extending portion, and each pair of con(cid:173)
`ductors is contained within an individual chamber.
`
`

`

`2058046
`
`14
`
`FIG. l
`
`FIG.2
`
`26
`
`20
`
`2058046
`
`FIG. |
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` FIG.2
`
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`Page 11
`
`CommScope Exhibit 1023
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`2058046
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`FIG. |
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` FIG.2
`
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`2058046
`
`FIG. |
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` FIG.2
`
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`

`

`2058046
`
`44
`
`FIG. 3
`
`FIG. 4
`
`2058046
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`Page 12
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`CommScope Exhibit 1023
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`2058046
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`2058046
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`

`

`205804G
`
`52
`
`54
`
`60
`
`· 68
`
`62
`
`FIG.5
`
`FIG.6
`
`2058048
`
`
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`Page 13
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`CommScope Exhibit 1023
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`2058046
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`2058046
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