EP0147070B1 - Forming cable core units - Google Patents

Forming cable core units Download PDF

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Publication number
EP0147070B1
EP0147070B1 EP19840308215 EP84308215A EP0147070B1 EP 0147070 B1 EP0147070 B1 EP 0147070B1 EP 19840308215 EP19840308215 EP 19840308215 EP 84308215 A EP84308215 A EP 84308215A EP 0147070 B1 EP0147070 B1 EP 0147070B1
Authority
EP
European Patent Office
Prior art keywords
twisted
units
speed
forming
tension
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
EP19840308215
Other languages
German (de)
English (en)
French (fr)
Other versions
EP0147070A2 (en
EP0147070A3 (en
Inventor
Jean Bouffard
Andrew Dumoulin
Marc Seguin
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nortel Networks Ltd
Original Assignee
Northern Telecom Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Northern Telecom Ltd filed Critical Northern Telecom Ltd
Publication of EP0147070A2 publication Critical patent/EP0147070A2/en
Publication of EP0147070A3 publication Critical patent/EP0147070A3/en
Application granted granted Critical
Publication of EP0147070B1 publication Critical patent/EP0147070B1/en
Expired legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B13/00—Apparatus or processes specially adapted for manufacturing conductors or cables
    • H01B13/02—Stranding-up
    • H01B13/0228—Stranding-up by a twisting pay-off and take-up device

Definitions

  • This invention relates to the apparatus and method for forming of cable core units.
  • twisting of insulated electrical conductors together to form twisted conductor units with a single direction of twist offers physical and electrical advantages when used in telecommunications cable cores.
  • the provision of twisted conductor units improves electrical characteristics such as a reduction in crosstalk.
  • a twisted conductor unit con. sists of two insulated conductors twisted together as a twisted pair.
  • twisting machines Conventionally, to twist conductors together in twisted pairs, high speed twisting machines are used. In such twisting machines, two lengths of insulated conductors are held upon reels which are freely rotatably mounted upon reel shafts in a reel cradle. To twist the conductor lengths together, each length is fed from its reel, around a rotatable pulley system and the lengths are then brought into side-by-side positions in which they are caused to rotate by means of a flyer or other framework, around an axis of the cradle. This rotation provides a double twist in the conductors and thus forms the twisted pair. The twisted pair is wound onto another reel immediately after twisting.
  • this reel is removed from the twisting machine and subsequently placed with other reels of twisted pairs as supply to a machine to draw the twisted pairs together to form a core unit.
  • the twisted pairs are then drawn through the core unit forming machine to provide a core unit of a plurality of pairs, e.g. 50 or 100 pairs. Hence, twisting into pairs is performed as a separate operation and on a different machine from the core unit forming machine.
  • the largely differing unequal tensions between twisted pairs achieved with differently spaced twisting machines in a tandem operation would result in great tension differences between twisted pairs after forming into core units.
  • the core units would become uncontrollably contorted along their lengths. Further processing of the units, e.g. to provide cable sheathing and jacketing, would present insurmountable problems as the core units would need to be non-contorted for these operations.
  • the differing tensions between the twisted pairs in the cable cause tightening together of the conductors in some regions of the cable more than in others thus varying the spacing between the conductors. This effects variations in mutual capacitance which is extremely undesirable in cable design.
  • This particular apparatus could not nullify any tension differential effect between twisted pairs nor could it solve the problem of excessive tension build-up in pairs approaching the stranding machine in manufacture of a core unit at faster speeds, e.g. at around 183 m/min (600 ft./ min).
  • the present invention is concerned with an apparatus for tandemizing the operation of twisting units, e.g., pairs of conductors with a continuous twist in one direction and then for forming a core unit while avoiding or minimizing the problems discussed above regarding the build-up of tension in the twisted pairs and the tension differences for high speed operation.
  • twisting units e.g., pairs of conductors with a continuous twist in one direction and then for forming a core unit while avoiding or minimizing the problems discussed above regarding the build-up of tension in the twisted pairs and the tension differences for high speed operation.
  • the present invention provides an apparatus for making a core unit of twisted units of individually insulated conductors comprising:-
  • the core unit forming and take-up means may comprise a stranding machine or a machine which merely groups the twisted units together without stranding.
  • the invention provides apparatus for making a core unit from twisted units of individually insulated conductors comprising:-
  • the forming and take-up means comprising drawing means to draw twisted units into the forming and take-up means
  • a tension equalizing means comprising a rotatable member disposed along the feedpaths of the twisted units, and drive means controlled to drive the rotatable member, said drive means having a drive speed dependent upon the drive speed of the drawing means to ensure that the unrestrained peripheral speed of the rotatable member is in excess of the draw speed of the twisted units into the forming and take-up means, lengths of the peripheral surface of the rotatable member presented to the feedpaths being insufficient to impart a driven speed to the twisted units above that of the draw speed into the forming and take-up means.
  • the tension equalizing means comprises rotatable members comprising drivable shafts surrounded by tubular members which are in slipping drivable engagement therewith.
  • the tubular members may be held in bearings upon the drivable shaft.
  • the unrestrained peripheral speed of the tubular members should exceed the draw speed of the unit into the forming and take-up means. For this purpose, it may be necessary to provide packed grease between the shafts and tubular members to increase the drive between them.
  • the tension equalizing means operates so that as twisted pairs of conductors travel side-by-side across and in contact with the tubular members, the rotational speeds of the tubular members are lessened compared to their unrestrained speeds and these lessened speeds are governed by a combination of tensions and speeds in all of the conductor pairs passing over the members.
  • the equalizing means To enable the equalizing means to operate, it is essential to place the twisting machines in series so that the feedpaths for the twisted pairs lie side-by-side and the tension equalizing means lies in the paths of the twisted pairs as they approach the forming and take-up means.
  • the invention further includes a method of forming a core unit of twisted insulated conductor units comprising twisting insulated conductors together into a plurality of twisted insulated conductor units with each unit having a single direction of twist along its length; drawing the twisted units as they are being formed, through a core unit forming and take-up means to form the core unit; and, as the twisted units approach the forming and take-up means, reducing the tension in all of the units by contacting them with a peripheral surface of at least one rotating member disposed in a tension reducing station and driven at a peripheral speed in excess of the draw speed into the forming and take-up means while the draw speed applies tension to the units as they leave the tension reducing station, peripheral surface contact with each unit in the tension reducing station sufficient only to increase the speed of the units towards, but not beyond, that of the draw speed.
  • the invention also includes a method of forming a core unit of twisted insulated conductor units comprising:-
  • apparatus for making a stranded core unit of 100 twisted pairs of conductors comprises apparatus for twisting the conductor pairs including a hundred twisting machines 10 arranged in four straight banks 12 with twenty-five machines in each bank.
  • the apparatus is capable of making cable core unit at a speed of up to and possibly in excess of 183 m/ min (600 ft./min).
  • a core unit forming and take-up means Spaced from one end of the four banks 12 is located a core unit forming and take-up means.
  • This comprises a stranding machine 13 comprising a stranding flyer 14 and including a "helper" capstan 15.
  • the "helper" capstan is to assist in the drawing of the core unit into the machine 13, the main force for which is taken by a motor 16 which drives a core unit take-up reel 17.
  • a drawing means in the form of a closing die 18 for drawing twisted conductor pairs together, and a binding head 20. This structure of closing die, binding head and stranding machine is conventional.
  • each of the twisting machines 10 comprises a cabinet 22 within which is located a reel cradle 24 for holding two reels 26 of individual insulated conductors in a rotatable fashion to enable the conductors to be drawn from the reels under the drawing influence of the stranding machine 14.
  • Each twisting machine may be of conventional construction for enabling the conductors to be drawn from the reels and to be twisted together as they pass through and outwardly from the machine.
  • each twisting machine comprises two_flyers 28 and associated pulleys to provide a balanced rotational structure while avoiding conventional balancing weights.
  • the two conductors 30 being removed from the reels 26 pass down- wardty together as described in the aforementioned specification and then through a selected one of the flyers 28 only.
  • the flyers are rotated by a drive motor (not shown) which is either an individual motor for each twisting machine or the twisting machines are driven from a common motor or motors. Flyer rotation causes the two conductors 30 to twist together with a double twist as is known.
  • Each twisting machine forms a sub-assembly on a main frame which extends lengthwise of its bank 12.
  • Each sub-assembly of twisting machine is detachable from the apparatus in a complete form.
  • each of the twisted pairs 32 as it emerges from the top of its twisting machine moves along the line of its associated bank 12 of twisting machines as it proceeds towards the stranding machine.
  • Each tension equalizing means comprises a shaft 36 which extends from side-to-side of the feedpaths for the twisted pairs, the shaft being held rotatably in bearings 38.
  • One end of each shaft 36 extends through a bearing 38 into the interior of a housing 40, upstanding from the general level of the twisting machines. This end of each shaft 36 has a V-grooved pulley 42 which is engaged by a drive belt 44.
  • the tension equalizing means are driven conveniently in groups of five whereby each of the belts 44 extends along the twisting machines so as to encompass five of the pulleys 42.
  • One of the drive shafts for each of the groups of five is driven directly by a drive motor 46, mounted upon the housing 40 and connected to its drive shaft 36 by an endless drive member 48 and pulleys 50 and 52 located on the drive shaft 36 and on the driven shaft for the motor 46.
  • a tubular member 54 carried in bearings 56 around shaft 36 so that it is in slipping drivable engagement with the shaft.
  • the tubular member 54 surrounds the shaft 36 so as to extend beneath the feedpaths for twisted pairs of conductors.
  • tubular member 54 will rotate at substantially the same angular speed as the shaft unless the member is restrained. While the bearings 56 may suffice for this purpose, the inside of the tubular member may also be packed with grease to hold it in more positive driving engagement with the shaft.
  • the drive motor 46 is coupled electrically to the line speed of the assembled twisted conductor units into the stranding machine, whereby the speed of the drive motor 46 is controlled in relation to the motor 64 so that the tension equalizing means is driven to provide a peripheral speed for the unrestrained tubular members 54, which is slightly in excess of the draw speed of the twisted pairs into the stranding machine.
  • the line speed of the assembled conductors is measured by a conventional means such as a rotor pulser device (not shown). The reason for this excess speed will be explained below.
  • the peripheral speed of the unrestrained tubular members is a question of choice dependent upon the tension reducing effects that are required. It has been found in practice that the peripheral speed of the tubular members 54 should exceed the speed of the twisted units into the stranding machine by up to 5% and preferably between 2% and 3%.
  • each bank 12 of twisting machines there are twenty-five tension equalizing means along each bank 12 of twisting machines.
  • the furthest equalizing means from the stranding machine supports only one twisted pair 32, i.e. that from the furthest twisting machine.
  • the number of twisted pairs supported by equalizing means increases along each bank 12, from equalizing means to equalizing means, until twenty-five pairs are carried by the equalizing means closest to the stranding machine.
  • Guide means is provided along the twisting machines 10 for holding the twisted pairs 32 spaced from one another to prevent the tension in one pair from influencing that in another.
  • This guide means takes the form of a plurality of vertical guide rods 58. These guide rods are located adjacent to but slightly downstream from each of the tubular members 54 and are held stationary in support brackets (not shown) in spaced apart positions axially of the tubular members.
  • the number of guide rods 58 used in respect of each equalizing means depends on the number of twisted pairs of conductors which will pass over that particular equalizing means. At the equalizing means, at Figure 4, there are five guide rods 58 provided which thus form guide means for four twisted pairs of conductors.
  • the tension reducing means for each group of twenty-five twisted pairs of conductors is in a tension reducing station and comprises two driven rotatable cylinders 60 and 62 around each of which the conductors must pass on the way to the stranding machine.
  • the two cylinders are of substantially equal diameter and have a common drive in the form of a drive motor 64, which is connected to the cylinder 62 by a drive belt 66.
  • a drive belt (not shown) also drivably connects the two cylinders together.
  • the drive motor 64 is electrically influenced by the linespeed also to provide a peripheral speed to each of the cylinders 60 and 62, which is slightly in excess of the drawing speed of the twisted pairs of conductors into the stranding machine. The degree of this excess in speed is again subject to choice dependent upon design, but in this particular machine lies between 1 and 5% and preferably is in the region of 3%.
  • each tension reducing means For purposes of clarity and to assist in an understanding of the operation of each tension reducing means, it is of importance to realize that the two cylinders 60 and 62 are not a capstan drive and do not operate as such in the accepted sense for drawing twisted pairs of conductors through apparatus in cable manufacture.
  • the cylinders 60 and 62 do not engage each of the twisted pairs along a sufficiently long arc of contact to provide enough frictional grip to draw the pairs from the twisting machines without the assistance of tension upon the pairs downstream of the cylinders and provided by the rotation of the reel 18. Hence, if the stranding machine were omitted, the cylinders 60 and 62 would be incapable of drawing twisted pairs from the twisting machines.
  • the tension reducing means are arranged in pairs, i.e. two for adjacent units 12. These two pairs are mounted together one on each side of a vertical framework 70, which is located at the downstream end of the units 12. Also mounted on the framework are two guide cylinders 72, one to each tension reducing means. These guide cylinders are freely rotatably mounted so as not to affect unduly the tensions in the twisted pairs and lie in positions below the cylinders 62. Each of the guide cylinders 72 is provided with twenty-five guide grooves 74 for accepting and maintaining apart the twenty-five twisted pairs of conductors.
  • each group of twenty-five twisted pairs of conductors moves forwardly into the stranding machine by passing round suitable guide rollers (not shown) for forming individual paths for the twisted pairs and for ensuring that their paths converge at the stranding head 16 for forming a core unit 75.
  • each of the twisting machines is loaded with two reels 26 of individually insulated conductors as shown in Figure 5.
  • the reel 17 is operated by the motor 16.
  • Each of the motors 46 and 64 is driven at a speed controlled by the line speed such that the peripheral speeds of each of the driven cylinders 60 and 62 and each of the unrestrained tubular members 54 is in excess of the draw speed of the twisted pairs into the stranding machine as discussed above.
  • Each of the twisted pairs 32 of conductors extends outwardly from its individual machine and along its own feedpath which takes it across and in contact with each of the tubular members 54 which lie in its path as it moves towards the stranding machine.
  • Each of the conductors also passes around the cylinder 62, the cylinder 60 and then around its guide cylinder 72 as shown in Figure 6.
  • the tension equalizing means overcomes this problem as will be described.
  • the amounts of tension present in each twisted pair produced during twisting by this high speed apparatus operating at around 183 m/min (600 ft. per minute) of core production may be around 1.36 kg (3 lbs).
  • the tension equalizing and reducing means operate as follows.
  • the tubular members 54 As the twisted pairs pass across and are supported by the tubular members 54, they travel at different speeds dependent upon their positions and path lengths in the cable core being formed by the stranding machine. There is a tendency for the tubular members to urge the twisted pairs in the forward direction because of the faster driven peripheral speed of the members. However, with regard to each tubular member 54, because of the slipping driving engagement between the tubular members and their shafts 36, the upstream tensions in the twisted pairs and the effect of their relative speeds combine to slow down the speed of rotation of the tubular member to a speed which is influenced by these tensions and relative speeds of the pairs.
  • the pairs of conductors with their relative tensions substantially closer than their upstream tensions then approach and go through their tension reducing means.
  • the pull by the stranding machine increases the frictional contact of the twisted pairs against the surfaces of the cylinders 60 and 62.
  • these cylinders are rotating at a peripheral speed which is greater than the throughput speed of the twisted pairs into the stranding machine, their degree of grip upon the pairs is insufficient to draw the pairs from the twisting machines at the peripheral speeds of the cylinders. The reason for this is explained above.
  • the degree of drive by the cylinders is dependent upon the frictional grip upon them by the pairs which increases and decreases in proportion to the downstream tension created by the draw of the stranding machine.
  • the pull by the cylinders upon each pair increases its speed until it approaches that of the draw speed of that pair into the stranding machine sufficiently to reduce the frictional grip of the pair upon the cylinders to remove the driving force. Any slight increase in the downstream tension from the cylinders will improve their driving engagement with the pair thereby reducing the tension again. It follows that the tension in any twisted pair upstream of the cylinders (e.g. up to 1.36 kg or 3 lbs.) is reduced on the downstream side to an acceptable level (e.g.
  • the tension equalizing means and the tension reducing means operate conveniently together.
  • the finished core unit is free of any contorted shape thus showing that internal tension differences are minor and negligible. Also, electrical properties do not differ significantly along the finished cable and, in particular, mutual capacitance variations are extremely slight and are well within commercially acceptable limits.

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  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Processes Specially Adapted For Manufacturing Cables (AREA)
  • Ropes Or Cables (AREA)
  • Communication Cables (AREA)
EP19840308215 1983-12-23 1984-11-27 Forming cable core units Expired EP0147070B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CA000444295A CA1217395A (en) 1983-12-23 1983-12-23 Forming cable core units
CA444295 1983-12-23

Publications (3)

Publication Number Publication Date
EP0147070A2 EP0147070A2 (en) 1985-07-03
EP0147070A3 EP0147070A3 (en) 1986-08-06
EP0147070B1 true EP0147070B1 (en) 1989-01-25

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ID=4126827

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Application Number Title Priority Date Filing Date
EP19840308215 Expired EP0147070B1 (en) 1983-12-23 1984-11-27 Forming cable core units

Country Status (6)

Country Link
EP (1) EP0147070B1 (fi)
JP (1) JPS617511A (fi)
CA (1) CA1217395A (fi)
DE (1) DE3476489D1 (fi)
ES (1) ES8606724A1 (fi)
FI (1) FI79417C (fi)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FI90697C (fi) * 1992-04-03 1994-03-10 Maillefer Nokia Oy Menetelmä ja sovitelma vaihtosuuntakertauksen yhteydessä
FR3007926B1 (fr) 2013-06-27 2016-01-08 Areva Np Transducteur a ultrasons

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1268902A (en) * 1968-07-15 1972-03-29 British Insulated Callenders Improvements in or relating to the manufacture of stranded conductors
US3715877A (en) * 1969-10-27 1973-02-13 Oki Electric Cable Communication cable
GB1303106A (fi) * 1970-01-23 1973-01-17
GB1428130A (en) * 1972-10-04 1976-03-17 Cortinovis Spa Apparatus for the manufacture of telephone cables
DD152225A1 (de) * 1980-07-23 1981-11-18 Mueller Bernd Dipl Ing Verfahren und vorrichtung zur zugkraftentlastung an sz-verseilmaschinen

Also Published As

Publication number Publication date
CA1217395A (en) 1987-02-03
EP0147070A2 (en) 1985-07-03
ES8606724A1 (es) 1986-04-16
FI845026A0 (fi) 1984-12-19
FI79417B (fi) 1989-08-31
ES538954A0 (es) 1986-04-16
DE3476489D1 (en) 1989-03-02
FI845026L (fi) 1985-06-24
EP0147070A3 (en) 1986-08-06
FI79417C (fi) 1989-12-11
JPS617511A (ja) 1986-01-14
JPH0381249B2 (fi) 1991-12-27

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