United States Patent (19)
`Pan et al.
`
`11)
`(45)
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`4,428,787
`Jan. 31, 1984
`
`54
`75
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`73)
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`(21)
`22
`(51)
`(52)
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`58)
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`WRAPPING OF CABLE CORE UNITS
`Ali Pan, Storrington; John R.
`Inventors:
`Ellwood, Napanee, both of Canada
`Assignee: Northern Telecom Limited, Montreal,
`Canada
`Appl. No.: 369,341
`Filed:
`Apr. 19, 1982
`Int. Cl. ............................................. HO1B 13/26
`U.S. C. ........................................ 156/54; 156/55;
`156/56; 156/201; 156/202; 156/463; 174/36;
`174/103; 174/113 R
`Field of Search ..................... 156/54, 55, 56, 201,
`156/202,463,465; 174/36, 103, 104, 113 R, 117
`
`56
`
`References Cited
`U.S. PATENT DOCUMENTS
`2,538,019 1/1951 Lee ........................................ 156/54
`2,947,652 8/1960 Burr.....
`174/117 RX
`3,404,217 10/1968 Kelly ................................. 56/54 X
`4,085,284 4/1978 Olszewski et al. .................... 174/36
`
`Primary Examiner-Robert A. Dawson
`Attorney, Agent, or Firm-R. J. Austin
`57
`ABSTRACT
`A device and method for wrapping a wrapping material
`to form S-shaped shields around a cable core of two
`side-by-side core units in which two tubes are provided
`for passage of the core units. A space between the tubes
`accepts the thickness of a central region of the wrap
`ping material which has side portions extending away
`from the central region. Concave turning surfaces ex
`tend partially around the tubes and approach each other
`as they extend towards an outlet end of the tubes. The
`core units pass along the tubes and the wrapping materi
`als passes along between the tubes while the turning
`surfaces progressively turn the side portions inwardly
`towards and around the tubes whereby the side portions
`are turned around the core units when these emerge
`from inside the tubes. In a practical arrangement, the
`turning surfaces are formed by the inside surface of a
`frusto core.
`
`15 Claims, 14 Drawing Figures
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`U.S. Patent
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`Jan. 31, 1984
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`Sheet 1 of 4
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`U.S. Patent
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`Jan. 31, 1984
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`Sheet 1 of 4
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`U.S. Patent
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`Jan. 31, 1984
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`Sheet 2 of 4
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`4,428,787
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`U.S. Patent
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`Jan. 31, 1984
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`Sheet 2 of 4
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`U.S. Patent
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`Jan. 31, 1984
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`Sheet 3 of 4
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`U.S. Patent
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`Jan. 31, 1984
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`Sheet 3 of 4
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`U.S. Patent
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`Jan. 31, 1984
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`Sheet 4 of 4
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`4,428,787
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`U.S. Patent
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`Jan. 31, 1984
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`Sheet 4 of 4
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`4,428,787
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`10
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`15
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`1.
`WRAPPING OF CABLE CORE UNITS
`This invention relates to the wrapping of cable core
`units.
`During the manufacture of a telecommunications
`cable it is sometimes required to wrap the core with a
`metallic shield. In certain constructions, the core is
`formed by two or more cable core units, each of which
`is formed from a plurality of pairs of conductors, the
`conductors in each pair being twisted together to re
`duce cross-talk. Core wrap is applied over the finished
`core at a jacketing operation, followed by aluminum
`shield and jacket extrusion. With such an arrangement,
`it is known to provide a metallic shield which not only
`passes around the cable core itself but also between the
`units of the core so as to separate them and shield one
`from another. In one particular construction of cable
`core, side-by-side core units are separated by a metallic
`shield which has a central region lying between the core
`units. At each side of the central region of the metallic
`shield extend side portions of the shield which are
`wrapped around the core units, one to each unit. The
`two side portions extend around their respective core
`units in the same direction of rotation relative to the
`25
`core so that the metallic shield is of an S shape in a
`cross-section through the cable core taken normal to its
`longitudinal direction. Such a shield should completely
`enclose the core units and to ensure that complete
`shielding is provided, each side portion of the shield
`overlaps the other side portion at the position where it
`extends from the central region of the shield. Such a
`construction is shown in U.S. Pat. No. 4,085,284
`granted Apr. 18, 1978 in the names of J. A. Olszewski
`and L. Jachimowicz and entitled "D Shield Telephone
`35
`Cables'.
`While the S shield construction has particular advan
`tages, it is nevertheless difficult to form. The present
`invention is concerned with a device for wrapping a
`metal strip material around core units of a cable core
`40
`which will provide an S shield around the core units.
`The invention is also concerned with a method of wrap
`ping a metal strip material around core units of a core in
`the manufacture of an S shield.
`Accordingly, the present invention provides a device
`for wrapping a metal strip material lengthwise along
`two side-by-side core units of a cable core comprising:
`two tubes, each having an inlet and an outlet end, the
`two tubes being relatively disposed with their outlet
`ends located closely adjacent and facing in the same
`direction, the tubes being spaced sufficiently to accept
`between them the thickness of a central region of wrap
`ping strip material; and
`material turning means for turning longitudinally
`extending side portions of the wrapping material around
`the core units, said turning means comprising turning
`surface portions of concave configuration in a cross-sec
`tion normal to the length of the two tubes, the turning
`surface portions extending partially around the tubes,
`one to each tube, with the turning surface portions
`facing across the tubes towards each other, and the
`turning surface portions extending along the tubes and
`approaching each other to become closely adjacent to
`the tubes at the outlet ends.
`In a preferred arrangement, the turning means com
`65
`pletely surrounds the tubes and defines a frusto-conical
`inwardly facing turning surface which includes the
`turning surface portions, and the turning surface tapers
`
`4,428,787
`2
`towards the outlet ends of the tubes. Also in a preferred
`construction, the tubes lie substantially parallel to each
`other for at least part of their lengths as they extend
`upstream from their outlet ends or, alternatively, the
`tubes converge as they extend to their outlet ends at
`which position they lie closest together.
`The invention also includes a method of wrapping a
`metal strip material lengthwise along two side-by-side
`core units of a cable core to locate a central region of
`the strip material between the core units and side por
`tions of the strip material extending from said central
`region, one at least partly around each of the core units,
`said method comprising:
`(a) passing the two core units, one down each of two
`tubes which are relatively disposed with outlet ends
`closely adjacent and facing in the same direction;
`(b) moving the strip material in the same general
`direction as the core units with said central region lo
`cated between the tubes and the side portions projecting
`laterally from between the tubes;
`(c) turning the side portions around the tubes, one
`around each tube, by urging the side portions inwardly
`towards the tubes while displacing longitudinal edges of
`the strip material angularly around the tubes; and
`(d) passing the core units side-by-side downstream
`from the outlets of the tubes while passing the strip
`material downstream from around the tube outlets with
`the central region of the strip material disposed between
`the core units and the side portions wrapped around the
`core units.
`Embodiments of the invention will now be described
`by way of example, with reference to the accompanying
`drawings in which:
`FIG. 1 is a cross-sectional view taken normal to its
`longitudinal axis of a telecommunications cable;
`FIG. 2 relates to a first embodiment and is a side
`elevational view of a device for wrapping a metal shield
`around core units of the cable of FIG. 1;
`FIG. 3 is a cross-sectional view of the device of FIG.
`2 taken along line III-III in FIG. 2;
`FIG. 4 is a cross-sectional view of the device taken
`along line IV-IV in FIG. 3;
`FIG. 5 is a cross-sectional view of the device taken
`along line V-V in FIG. 3;
`FIG. 6 is a side elevational view, in cross-section, of
`apparatus for wrapping the metal shield around core
`units of the cable of FIG. 1, said apparatus including a
`device as shown in FIGS. 2 to 5;
`FIGS. 7, 8, 9 and 10 are cross-sectional views respec
`tively through the apparatus of FIG. 6 along lines VII
`-VII, VIII-VIII, IX-IX, and X-X;
`FIG. 11 is a cross-sectional view similar to FIG. 4
`through a device according to a second embodiment;
`FIG. 12 is a side elevational view, partly in cross-sec
`tion of an apparatus including a device according to a
`third embodiment;
`FIG. 13 is a cross-sectional view along line XIII-X-
`III in FIG. 12; and
`FIG. 14 is a cross-sectional view taken along lines
`XIV-XIV in FIG. 12.
`As shown in FIG. 1, a telecommunications cable 10
`comprises two core units 12 each formed from twenty
`five pairs of conductors, the conductors in each pair
`being twisted together. The two core units are each of
`substantially 'D' shape in that they have a partially
`circular surface and a substantially flat surface 16, the
`flat surfaces being in opposition as shown by FIG. 1, to
`
`45
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`4,428,787
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`4.
`around the tubes and face each other across the tubes as
`form the core units in their assembled condition into a
`core of substantially circular cross-section.
`is clear from FIGS. 8 and 9 as will be described.
`Towards an upstream end of the tube 42, and in the
`The core is provided with a metal shield 18. This
`region of the kink in the tubes 30, are disposed two
`shield is formed from aluminum strip and has a central
`forming plates 52 for feeding the aluminum strip mate
`portion 20 which lies between the two flat surfaces 16 of 5
`rial into the tube 42 with an initial shape in cross-section
`the core units. The shield extends outwardly from each
`which will enable the member 46 to urge the side por
`side of the central region to form a side portion 22 and
`tions of the strip around the core units to provide the
`each side portion surrounds a respective core unit 12.
`structure shown in FIG. I. As shown by FIG. 3, the
`The side portions continue completely, each around the
`two forming plates 52 are attached to upper ends of the
`curved surface of its own core unit 12, and each side
`brackets 44 and extend across the opening of the tube
`portion 22 overlaps a part of the other side portion
`42. Between them and in conjunction with the inner
`adjacent to the position at which it merges with the
`surface 48, the plates 52 provide an opening or slot 54 of
`central region 20. The aluminum strip is covered on
`'S' shape. This 'S' shaped slot has two ends 55 extending
`both sides with a plastics layer (not shown).
`between the plate 52 and the surface 48, and a central
`Surrounding the metal shield 18 is a core wrap 14
`region 57 which is aligned with a gap provided between
`formed from plastic material in the form of tape or strip
`the two tubes 30. This gap and the width of the slot S4
`and an aluminum shield 24 extends around the core
`are sufficient to accommodate the thickness of the mate
`wrap. The shield 24 is coated on both sides with plastic
`rial to be used for the shield 18 as the material is fed
`and has overlapped ends 25. A jacket 26 of plastics
`through the slot.
`20
`material such as polyethylene is extruded around the
`The device also comprises an edge guide means
`outside of the shield. The heat from the extrusion pro
`which extends inwardly of the cylinder 42 towards the
`cess causes the plastic on the outer surface of the shield
`tubes 30. This guide means comprises two diametrically
`24 to fuse to the plastic of the jacket and also causes the
`opposed guide pegs 56 which extend through circum
`plastic of the overlapped ends 25 to bond together.
`ferentially extending slots 58 (FIG. 2), the pegs 56 being
`25
`The shield 18 is formed around the core units by a
`'T' shaped and having heads 60 which provide guides
`device 28 (FIG. 2) which is constructed as follows.
`for the side edges of the wrapping material as it passes
`The device 28 comprises two tubes 30 which are
`along the cylinder 42. These heads extend longitudi
`kinked at their upstream ends 32 so that they converge
`nally of the cylinder 42 so that the edges of the material
`as shown in FIG. 5 towards a position a short distance
`will pass along the heads for alignment purposes. A nut
`downstream from their inlet ends 34. For the remainder
`62 received upon each peg 56 is provided for screw-fit
`of their lengths from the kinked position, the tubes
`ted assembly of the pegs onto the cylinders 42 and also
`extend substantially parallel to their outlet ends 36. The
`to enable its peg to be adjusted in position circumferen
`tubes are flared and care of circular cross-section at
`tially around a slot 58 so as to adjust the desired position
`their inlet ends. In each tube at its kinked position there
`of a side edge of the material as it passes along the cylin
`35
`is a 'D' shaped die 38 of the shape shown in FIG. 3. The
`der 42.
`shape of each tube changes progressively from circular
`The device 40 forms part of an apparatus for applying
`to the 'D' shaped of the die downstream from its flared
`the shield to the core of the cable. This apparatus also
`inlet. The die 38 is for shaping a substantially circular
`includes a closing die 64. This closing die operates in a
`core unit into the 'D' shape it assumes in the cable core
`normal fashion for closing dies in that it operates to urge
`shown in FIG. .
`the shield closely into contact with the core after shap
`The two tubes are held in fixed relative positions by
`ing. The closing die is followed downstream by a con
`being mounted within a material turning means 40
`ventional binding device 66 which carries a spool 68 of
`which comprises a substantially cylindrical tube 42
`binding tape 70 which is wrapped automatically around
`surrounding the tubes 30. The tubes 30 are held substan
`the shield covered core as it passes from the binding
`45
`tially centrally down the tube 42 by securing means in
`head 66.
`the form of two brackets 44 which are secured one to
`In use, the two core units 12 are passed one down
`each tube 30. The brackets 44 extend diametrically
`each of the tubes 30, out through the outlet ends of the
`outwards from the tubes 30 to be held by screws to the
`tubes, through the closing die and thence through the
`inner surface of the cylindrical tube 42.
`binding device 66 as shown in FIG. 6. As the units pass
`Downstream of the cylindrical tube 42, the turning
`into the inlet ends 34 of the tubes 30 and then through
`means 40 also comprises detachable frusto-conical
`the dies 38, the core units are formed into their 'D'
`member 46 which is received in screw threaded engage
`shape. A length 72 of aluminum strip is passed between
`ment with the tube 42. As shown by FIGS. 4 and 5, the
`the core units 12 as they approach the tubes 30. The
`frusto-conical member has a larger diameter end which
`aluminum strip then proceeds between the tubes and the
`55
`merges with an inner cylindrical guide surface 48 of the
`side portions of the strip are received within the slot 54
`of the guide plates 52 to form the strip into 'SS' shape
`tube 42. The member 46 defines a frusto-conical in
`wardly facing material turning surface 50 which at a
`according to the slot. As the material 72 proceeds along
`downstream end of the member 46, i.e. adjacent to the
`the cylinder 42, the edges of the material are engaged by
`outlet ends 36 of the tubes 30, lies close to the outer
`the heads 60 of the pegs 56 to hold the material in its
`desired position. The configuration of the material 72,
`surfaces of the tubes 30.
`The device 40 is provided for turning strip material
`which is as shown by FIG. 7, is maintained until the
`around the core unit 12 during formation of the shield
`material enters the frusto-conical surface 50. Upon en
`18 by engagement with turning surface portions of the
`tering this surface and moving along it, the decrease in
`concave configuration of the surface 50. These turning
`diameter of the surface 50 urges the side portions of the
`surface portions are parts of the surface 50 which are
`material towards the tubes 30 and this movement is
`simultaneously accompanied by necessary displacement
`engaged by the strip as it passes downstream through
`the member 46 and these portions extend partially
`of the side portions of the material angularly around the
`
`30
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`tubes so that the side portions progress inwardly toward
`rate for efficient turning of the side portions of the
`the tubes 30. Hence, upon reaching the position of
`shield to take place.
`FIGS. 8 and 9, the side portions of the material 72 are
`The device 80 is used in apparatus similar to that
`turned around the tubes to the positions shown.
`shown in FIG. 6 and need be described no further.
`In a third embodiment shown by FIG. 12, a device 92
`The diameter at the outlet to the frusto-conical mem
`ber 46 is such that upon the core units issuing from the
`is completely frusto-conical without a cylindrical mem
`outlets 36 of tubes 30 together with the issuing of the
`ber and has two core unit guide tubes 94 which extend
`in convergent fashion from a large diameter upstream
`material 72 from the member 46, the material 72 sub
`stantially surrounds both of the core units 12 and lies
`end of the member 92, through the member, to its
`close to them without being in intimate engagement
`downstream end 96 at which the tubes 94 terminate.
`with the core unit. At this stage, while the material
`Each tube is held at an upstream end portion to the
`forms the shield 18, the side portions of the shield are
`member 92 by brackets 98 as shown by FIG. 13.
`not closed completely down onto the core units 12.
`In use of the device 92, the device is located again
`Between the downstream end of the member 46 and
`upstream of a closing die and binder as described in the
`the closing die 64 there is a gap of several inches. This
`first embodiment. Core units are fed through the tubes
`gap, which may be around 6 inches, is provided to
`94, as shown in FIG. 12, and out through the down
`enable visual inspection of the assembly of core units
`stream ends of the tubes with the shield material 18
`and the shield 18 as it issues from the member 40. As the
`wrapped around them. The length 72 of material is fed
`assembly moves through this gap, there is a tendency
`through the tubes as described in the preceding embodi
`for the side portions 22 of the shield to spring slightly
`ments and then through a forming die plate 100 (FIG.
`20
`away from the core units and this action does not assist
`13) at the upstream end of the member 92. This plate
`in closing the shield. Some method needs to be provided
`operates similarly to the plate 52 described in the first
`for restricting the degree of opening of the shield. The
`embodiment and forms the material 72 into 'S' shape as
`side portions 22 of the shield are held down upon the
`has previously been described. As the material 72 passes
`core units 12 by two fingers 74 which are diametrically
`along the member 92, the edges of the side portions are
`oppositely disposed in the gap on each side of the core.
`urged angularly around the tubes to curve the side
`These fingers 74 are adjustable in position by mechani
`portions around the tubes. The amount of material lying
`cal means (not shown) and are merely held against the
`between the tubes moves out from between the tubes as
`they converge together and progresses around the sur
`side portions 22 to retain them in position down on the
`core units as the assembly proceeds towards the closing
`face of the member 92 so as to form the side portions 22
`die.
`and the central portion 20 between them (FIG. 14). The
`Upon reaching the closing die, the core units and the
`assembly of core units and shield then issues from the
`shield 18 proceed therethrough and the closing die
`member 92 with the shield closely surrounding the core
`urges the side portion 22 down more closely into
`units 12 but not in intimate engagement therewith, i.e. in
`contact with the core units. This action effectively
`the manner described in the first embodiment.
`overlaps the edges of the side portions 22 each around
`It is worthy of note that in this embodiment the tubes
`the other side portion at the position where the side
`94 are not of "D' shape as described in the first embodi
`portion merges with the center region 20. The position
`ment but are of circular cross-section to accommodate
`of the shield is then as shown in the cable assembly of
`in sliding fashion the core units 12 before these are
`FIG. 1. The assembly of shield and core units then
`formed into 'D' shape. Upon the assembly of core units
`40
`proceeds through the binder 66 and the binding tape 70
`and the shield issuing from the downstream end of the
`member 92, the assembly passes through the closing die
`is wrapped around the shield 18 before the assembly
`proceeds to have the core wrap 14 applied and to an
`102 which not only urges the side portions of the shield
`extrusion device for extruding the jacket 26 around the
`intimately into contact with the core units, but also has
`assembly.
`a suitably shaped die to bring the core units together
`45
`The invention provides a simple method of providing
`and form them into 'D' shape. The core is then of sub
`a shield 'S' shape from a single layer of material to
`stantially circular shape as shown in FIG. 1.
`extend around two core units of a core while shielding
`The above embodiments have been described for the
`one from the other. The operation of the device is sim
`manufacture of cable as shown in FIG. 1. However, a
`ple and automatically forms the shield during progres
`cable similar to FIG. 1 and devoid of the aluminum
`50
`sion of the shield material and the core units through a
`shield 18 and core wrap 14 may have its screen 18 ap
`continuous cable forming process.
`plied by apparatus according to any of the above em
`In a second embodiment, as shown by FIG. 11, a
`bodiments. In this further cable (not shown), a core
`wrap is positioned around each core unit 12, the core
`device 80 is similar in construction to the device 40 of
`units then being brought together in the device 28, 80 or
`the first embodiment. The device 80 differs from that of
`55
`the first embodiment, however, in that while it has a
`92 and the shield 18 applied as described above. With
`cylindrical member 82 preceding a frusto-conical mem
`this cable, the jacket 26 lies around the shield 18 and the
`ber 84, the change from the cylindrical forming surface
`plastic covering the shield is bonded to the jacket. Also,
`to the frusto-conical surface does not take place at the
`the ends of the shield 18 are bonded to the parts of the
`connecting position between the two members. As
`shield which they overlap by fusing together of the
`shown by FIG. 11, the cylindrical member 82 is formed
`covering plastic layers under the influence of the extru
`partially along its length with a cylindrical surface 86
`sion heat.
`and this then merges into a frusto-conical surface 88.
`What is claimed is:
`1. A device for wrapping a metal strip material
`The surface 88 continues downstream as a frusto-coni
`lengthwise along two side-by-side core units of a cable
`cal surface 90 of the member 84 which is screw-fittedly
`core comprising:
`received within the downstream end of the member 80.
`It should be noted that, as shown by FIG. 11, the frusto
`two tubes each having an inlet end and an outlet end,
`the two tubes being relatively disposed with their
`conical surfaces 88 and 90 need not taper at the same
`
`35
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`25
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`30
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`65
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`

`

`4,428,787
`7
`8
`outlet ends located closely adjacent and facing in
`member, the second turning member being detachabis
`the same direction, the tubes being spaced suffi
`assembled to the first turning member.
`ciently to accept between them the thickness of a
`10. A device according to claim 8, having edge guide
`central region of wrapping strip material;
`means extending inwardly of the first turning member
`material turning means for turning longitudinally
`to engage the longitudinal edges of the wrapping mate
`extending side portions of the wrapping material
`rial and hold the material in a desired position relative
`to the tubes during a wrapping operation.
`around and out of intimate contact with the core
`units, said turning means comprising turning sur
`11. A device according to claim 3, wherein the tubes
`face portions of concave configuration in a cross
`have 'D' shaped dies for forming the core units into 'D'
`section normal to the length of the two tubes, the
`shape in cross-section.
`turning surface portions extending partially around
`12. A device according to claim 1, wherein at an inlet
`the tubes, one to each tube, with the turning sur
`end of the turning means, at least one forming plate is
`face portions facing across the tubes towards each
`provided which defines an 'S' shape slot for shaping
`other, and the turning surface portions extending
`material into an 'S' shape with turned side portions
`along the tubes and approaching each other to
`contacting the turning surface portions of the turning
`become close to but spaced from the tubes at the
`means, the slot having a central region which extends
`outlet ends; and
`between the tubes.
`a closing die downstream of the tubes and of the
`13. A method of wrapping a metal strip material
`material turning means and having a die surface
`lengthwise along two side-by-side core units of a cable
`defining a passage of smaller cross-section than the
`core, the units devoid of jackets and comprising a plu
`20
`turning surface portions to draw the side portions
`rality of pairs of twisted conductors stranded together,
`of the material into close intimate contact with the
`in which a central region of the strip material is located
`between the core units and side portions of the strip
`COe.
`2. A device according to claim 1, wherein the turning
`material are provided to extend laterally of the central
`means surrounds the tubes and defines a frusto-conical
`region, one at least partly around each of the core units,
`25
`inwardly facing turning surface which includes the
`said method comprising:
`turning surface portions, the turning surface tapering
`(a) passing the two core units, one down each of two
`towards the outlet ends of the tubes.
`tubes which are relatively disposed with outlet
`3. A device according to claim 2, wherein the tubes
`ends closely adjacent and facing in the same direc
`lie substantially parallel for at least part of their lengths
`tion;
`30
`upstream from their outlet ends and each turning sur
`(b) moving the strip material in the same general
`face portion approaches its associated tube as it ap
`direction as the core units with said central region
`proaches the outlet end of the tube.
`located between the tubes and the side portions
`4. A device according to claim 2, wherein the tubes
`projecting laterally from between the tubes;
`converge for at least part of their lengths towards their
`(c) turning the side portions around the tubes, one
`35
`outlet ends at which position they are closest together
`around each tube, by urging the side portions in
`and each turning surface portion approaches its associ
`wardly towards the tubes while displacing longitu
`ated tube as it approaches the outlet end of the tube.
`dinal edges of the strip material angularly around
`5. A device according to claim 2, wherein the turning
`the tubes;
`means also comprises a substantially cylindrical in
`(d) passing the core units side-by-side downstream
`wardly facing guide surface with the frusto-conical
`from the outlets of the tubes while passing the strip
`turning surface extending away from the cylindrical
`material downstream from around the tube outlets
`guide surface while tapering towards its end of smaller
`with the central region of the strip material dis
`diameter.
`posed between the core units and the side portions
`6. A device according to claim 5, including securing
`wrapped around but not in intimate contact with
`45
`means which attach the tubes to the turning means
`the core units; and
`along the part of the turning means which defines the
`(e) suddenly closing the side portions against and into
`cylindrical guide surface.
`intimate contact with the core units.
`7. A device according to claim 2, having material
`14. A method according to claim 13, comprising:
`edge guide means extending inwardly of the turning
`shaping the core units into a substantially 'D' configu
`means towards the tubes to engage the longitudinal
`ration in cross-section by passage through a die
`edges of the wrapping material and hold the material in
`opening in each tube, the core units of 'D' shape
`a desired position relative to the tubes during a wrap
`having confronting flat surface regions between
`ping operation.
`which the central region of the tape is disposed.
`8. A device according to claim 5, wherein the turning
`15. A method according to claim 13, comprising
`means comprises a first turning member which is
`passing the core units through the tubes and after wrap
`formed with a cylindrical guide surface- and a second
`ping of the material around the core units, feeding the
`turning member formed with the frusto-conical turning
`assembly of core units and wrapping material through a
`surface, the two members being attached together.
`die which urges the material intimately into contact
`9. A device according to claim 8, wherein the two
`with the core unit and shapes the core units into a sub
`60
`tubes are secured to the first turning member and extend
`stantially 'D' configuration in cross-section.
`from the first turning member into the second turning
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`55
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`sk
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`k
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`65
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`10
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`15
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`50
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`