EP0207612B1 - Manufacture of telecommunications cable core units - Google Patents
Manufacture of telecommunications cable core units Download PDFInfo
- Publication number
- EP0207612B1 EP0207612B1 EP19860303803 EP86303803A EP0207612B1 EP 0207612 B1 EP0207612 B1 EP 0207612B1 EP 19860303803 EP19860303803 EP 19860303803 EP 86303803 A EP86303803 A EP 86303803A EP 0207612 B1 EP0207612 B1 EP 0207612B1
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- European Patent Office
- Prior art keywords
- conductor
- array
- core unit
- conductor units
- units
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- 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
- H01B13/04—Mutually positioning pairs or quads to reduce cross-talk
Definitions
- stranding machines While stranding machines are obviously very efficient in producing the required core unit structure, they are of complex construction.
- a core unit take-up reel is required which need to be rotated not only around its own axis, but also around the axis of the machine so as to simultaneously provide the stranding action of the stranding machine and also take-up the core unit after its formation.
- the take-up reel especially when partially or almost completely loaded with core unit, has substantial weight and thus provides a substantial moment of inertia as it is rotated around the axis of the stranding machine to provide the stranding action.
- stranding machines are very heavily built and are expensive to manufacture.
- the horizontal flights are displaced progressively vertically upwards from one changing position to the next in the downstream direction of the feedpath by locating the pulleys upwardly from each position changing means to the next on supports 55 (see Figure 5).
- the horizontal flights of the upper group are displaced vertically downwards in a downstream direction of the feedpath.
- the horizontal flights of the two groups oppose each other across the feedpaths and approach each other progressively in a downstream direction.
- each position changing means is provided with its own reversible stepper motor 52 (see Figures 2, 3 and 7). All of the stepper motors 52 are mounted remotely from the horizontal flights by being attached to upper and lower panels 54 of the machine stand. Each motor is directly drivably connected to a sprocket 50 which engages with its respective chain 44 as shown by Figure 7.
- the drive motors may be driven at the same speed as each other whereby the guides 34 move along their horizontal flights at the same speed but out of phase with each other. However, in this embodiment the drive motors are driven at speeds which are slightly different from each other so that the positional relationship of all of the guides is continuously changing while reducing the possibility of a set pattern of movement of the guides 34.
- the profile die orifices 75 and 77 have their centers disposed upwardly from the closing die orifice 78.
- the upturned side portions of the array engage the sides 80 of the orifice with the center of the array engaging towards the bottom regions of the orifice.
- the conductor pairs at the upwardly turned side edges are then directed more towards the upper regions of the profile die orifice 77 as these regions are lower than those of the die orifice 75.
- Figure 13 shows, as dots, the positions of all of the conductor pairs 10 at a specific time as they emerge from the position changing means assembly 20. At that time, two of the conductor pairs 10a and 10b are in positions 82 and 84 respectively as shown by Figure 13. Both conductor pairs 10a and 10b are moving towards the left hand side of Figure 13 with conductor pair 10a having only just commenced movement in that direction and conductor pair 10b almost at the end of its movement before returning in the opposite direction.
- each of the pairs has some control over their position in the finished cable core unit.
- the final position of each of the pairs is, of course, also dependent upon the pressure applied to them in a lateral direction by other pairs as they approach and enter the closing die 18.
- each pair moved progressively in one direction and then in the other around the axis of the core unit as it extends along the core unit, but also its radial position in the core unit is automatically determined. This is illustrated by the positional movement and the path followed by conductor pairs 10a and 10b as they turn around the core unit axis along an axial length of the core unit.
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- Manufacturing & Machinery (AREA)
- Processes Specially Adapted For Manufacturing Cables (AREA)
Description
- This invention relates to the manufacture of telecommunications cable core units.
- A telecommunications cable is constructed 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, e.g. fifty or one hundred pairs, or larger cores, i.e. up to thirty-six hundred twisted pairs, each comprise a plurality of core units. The twisted pairs are stranded together to form a core unit with the conductors of each pair twisted together with a predetermined lead to the twist, i.e. the distance taken along the pair for each conductor to complete a single revolution along its path. This distance is normally referred to as the "twist lay" of the pair. There are different twist lays provided for the twisted pairs in a core unit with a pair having a particular twist lay being adjacent to other pairs of different twist lays. Care is taken, so far as is practicable, to ensure that pairs of equal or similar twist lays are separated from each other. 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 the pairs and to lower the coefficient of deviation of mutual capacitance of pairs in the cable. To reduce the pair-to-pair capacitance unbalance and to improve 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 distances apart. In a suggested method for changing the relative position 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 vertically tiered fashion. This method was first suggested by S. Norblad of Telefonaktiebolaget L.M. Ericsson, in a paper entitled "Capacitance Unbalance Telecommunications Networks" read before the International Wire and Cable Symposium in 1971.
- Further methods of changing the relative positions of the conductor pairs have also been suggested. These include the method and accompanying apparatus which is described and claimed in EP-A-170352, and entitled "Manufacture of Telecommunications Cable Core Units" in the name of J.N. Garner. In that patent application, apparatus is described for forming a core unit in which a plurality of position changing means are provided for conductor units, each position changing means operating to change the position of a conductor unit across the feedpath relative to other units. In this apparatus, each position changing means comprises a guide and means to reciprocally move the guide across the feedpath. The position changing means are disposed in series with one another along the feedpath with their reciprocating means overlapping one another in a view taken along the feedpath and the arrangement of position changing means is such that each guide is aligned for unobstructed passage of a conductor unit as it moves along the feedpath.
- Thus although suggestions have been made to move the conductor pairs relative to one another in the finished core unit, it still remains necessary to use a stranding machine to provide a core unit in which the twisted conductor units move around the axis of the core unit as they extend along its length. This type of assembly of core unit is preferred, because it provides a more positive assembly of the conductor units in a core unit and also enables the finished cable to be flexed either during spooling or laying into operating position by virtue of the fact that the conductor units extend angularly around the core unit.
- The manufacture of telecommunications cable core units is disclosed in EP-A-170,352. The relative positions of conductor pairs along a telecommunications cable core are changed by passing the unstranded pairs, as they approach a core unit forming means, through individual guides which are reciprocally moved across a feedpath for the pairs, the guides being disposed in series along the feedpath with each guide aligned for unobstructed passage of its conductor unit along the feedpath. In this construction, means to reciprocate each guide overlaps those of other guides thereby reducing the total height of the apparatus.
- A method and apparatus for forming cable core units is disclosed in EP-A-147070, in which pairs of twisted conductors are formed upon individual twisting machines, the twisted conductor pairs then being fed in-line to a core-forming device by passing the pairs through a tension-reducing means. The latter reduces the tension in each pair while allowing the lengths of the pairs to be different from pair-to-pair as they move into the core-forming device. A tension-equalising device is also provided which averages out the tension between the conductor pairs.
- While stranding machines are obviously very efficient in producing the required core unit structure, they are of complex construction. A core unit take-up reel is required which need to be rotated not only around its own axis, but also around the axis of the machine so as to simultaneously provide the stranding action of the stranding machine and also take-up the core unit after its formation. The take-up reel, especially when partially or almost completely loaded with core unit, has substantial weight and thus provides a substantial moment of inertia as it is rotated around the axis of the stranding machine to provide the stranding action. To provide for such a rotational movement, stranding machines are very heavily built and are expensive to manufacture. In addition to this, because of the location of the take-up reel and the need for it to rotate about two axes, it is extremely tedious and time consuming operation for completely loaded take-up reel to be removed and for a succeeding and empty reel to be located within the stranding machine.
- It is the object of the present invention to provide a method and apparatus for forming a core unit which avoids the use of a stranding machine while causing conductor units to extend around the core unit at an angle to its length. It is also an object of the invention to provide a method and apparatus which, while avoiding the use of a stranding machine, enables the core unit so formed to be assembled directly onto a take-up reel which is rotating in one direction only or alternatively, enables the completed core unit to be moved directly in line or in tandem with apparatus which provides the core unit with either a surrounding sheath or shield or a jacket material or both.
- Accordingly, the present invention provides apparatus for forming a core unit from telecommunications conductor units each formed of twisted together insulated conductors comprising, in a downstream direction along a passline for the conductor units, a position changing means for changing positions of laterally spaced apart conductor units across the passline and relative to other conductor unit, conductor unit array forming means comprising at least two rollers having rotational axes one downstream from the other with opposed peripheral surfaces of the rollers spaced-apart one each side of the passline, each surface changing in diameter along its length with one surface having its smallest diameter and the other its largest diameter at a position intermediate its axial ends, the positions and configurations of the surfaces being such that together they are operable to position the conductor units in an array as the conductor units move towards, past and then beyond the rollers, the array extending in two planes in a section taken across the array dependent upon the positional charge caused by the position changing means; and core unit forming means comprising a closing die for forming a core unit from the conductor units.
- In a preferred construction, the position changing means is operable for continuous operation to move the conductor units across the passline in a continuous fashion. In a further preferred arrangement, one of the rollers has a concave peripheral surface and the other a convex peripheral surface.
- The invention also provides a method for forming a core unit from telecommunications conductor units each formed of twisted together insulated conductors, the method comprises (a) moving a plurality of conductor units in laterally spaced relationship along a passline while:- moving the laterally spaced conductor units into an array across the passline, the array of controlled configuration extending in two planes in a section across the passline, and moving each conductor unit alternately in opposite directions across the passline independently of other units at a position upstream from the array so that each conductor unit moves alternately in opposite directions across the array and the conductor units move laterally relative to one another in the array; and (b) causing the conductor units in the array to converge as they continue along the passline so as to bring them together to form the core unit with the relative positions of the conductor units changing in the core unit as influenced by their relative positions in the array and with each conductor unit moving around the core unit axis alternately in opposite directions as it moves along the core unit and as influenced by its movement across the array.
- By the use of the apparatus and the method according to the invention, conductor units are caused to move around the axis of the core unit as they extend along its length. While the conductor units will not continuously move around the core unit axis in a single direction, as in conventional constructions, nevertheless the advantages obtained by a conventional core unit construction will be obtained with a core unit made in the inventive manner. Movement of the conductor units in opposite directions around the axis of the core unit formed by the inventive method and apparatus provide the angular orientation relative to the axial direction so as to enable the core unit and the finished cable to be flexed in the acceptable fashion. In the core unit made by the method according to the invention, if sufficient lateral movement is provided for each of the conductor units in the array, then each conductor unit as it extends axially may also move around the core unit axis for almost a complete revolution in each direction.
- One embodiment of the invention will now be described, by way of example, with reference to the accompanying drawings, in which:-
- Figure 1 is a side elevational view of apparatus for forming a core unit from conductor pairs;
- Figure 2 is a side elevation of a position changing means for conductor pairs and on a larger scale than shown in Figure 1;
- Figure 3 is a view of the position changing means in the direction of arrow III in Figure 2;
- Figure 4 is a cross-sectional view of the position changing means taken along line IV-IV in Figure 2 and on a larger scale;
- Figure 5 is a end view of a detail in the same direction as Figure 3 and on a larger scale;
- Figure 6 is a cross-sectional view taken along line VI-VI in Figure 2;
- Figure 7 is a cross-sectional view taken along line VII-VII in Figure 6 and on a larger scale;
- Figure 8 is a side elevational view of a conductor unit array forming means and core unit means and shown on a larger scale than in Figure 1;
- Figure 9 is a view of a part of the apparatus in Figure 8 and in the direction of arrow IX in Figure 8;
- Figure 10 is a view of the apparatus taken in cross-section of the conductor units along the line X-X in Figure 8;
- Figures 11 and 12 are cross-sectional views respectively taken along lines XI-XI and XII-XII in Figure 8;
- Figure 13 is a cross-sectional view through the conductor units taken along the line XIII-XIII in Figure 1 to show in diagrammatic fashion, the relative positions of conductor units from time-to-time as they issue from the position changing means;
- Figures 14, 15 and 16 are views similar to Figure 13 taken along lines XIV-XIV, XV-XV and XVI-XVI in Figure 8 to show the relative positions in the conductor units after passage through the array forming means and also during convergence of the conductor units during core unit formation;
- Figure 17 is a diagrammatic cross-sectional view through a finished core unit and showing the positional change of various conductor units within the core unit;
- Figure 18 is a view similar to Figure 1 of one end of a modification of the embodiment; and
- Figure 19 is a view similar to Figure 1 of a second embodiment.
- The apparatus according to the invention is particularly useful for a tandem or "in-line" operation for twisting individually insulated conductors together into conductor pairs and then for forming these conductor pairs into a core unit.
- As shown in the embodiment, twenty-five conductor pairs 10 (Figure 1) each formed from two twisted together individually insulated conductors, are drawn from twenty-five
reels 12 of the conductor pairs in conventional fashion. Acore unit 14 is formed at the downstream end of the apparatus by passing the conductor pairs through aclosing die 16 which draws the conductor pairs together and abinding head 18 at which position a binding material is closed around the drawn together conductor pairs to hold them together in conventional manner. The closing die forms part of a core unit forming means 24 for causing convergence of the conductor units into a core unit. - Disposed between the
reels 12 and themeans 24 are a position changingmeans assembly 20 and a conductor unitarray forming means 22. The position changing means and the conductor unit array forming means ensure that the conductor pairs are moved relative to each other and in such a fashion that the finished core unit has conductor pairs extending around its axis alternately in each direction as the conductor units extend along the length of the core unit. - The position changing
means assembly 20 and a guide means 26 which precedes it are of the construction described in EP-A-170352 entitled "Manufacture Of Telecommunications Cable Core Units" in the name of J.N. Garner. - The guide means 26 comprises a
roller 28 which is freely rotatably mounted upon a machine frame (not shown) and the roller is provided with a plurality of annular grooves (not shown) as described in the aforementioned application. As can be seen from Figure 1, the conductor pairs are fed from thereels 12 and through the guide means. Each conductor pair is disposed in its own individual groove in theroller 28 so as to maintain the conductor pairs separate from one another as they approach the position changingmeans assembly 20. - As shown by Figures 2 and 3, a plurality of position changing means 30 are provided in the
assembly 20 for the conductor pairs, one position changing means for each pair. The position changing means are all housed within a straightsided frame 32. The position changing means are disposed in two groups, one vertically above the other, with the position changing means in each group lying in series with one another along the feedpath for the conductor pairs. Each position changing means comprises aguide 34 for a conductor pair. This guide, as shown by Figure 4 has aguide passage 36 that is formed with twoside wings 38 attached withrivets 40 to an endless moving means for the guide, the moving means comprising aflat plastics belt 42 through which therivets 40 pass. The endless moving means also comprises achain 44 which extends between the ends of the belts as shown in Figure 7. Each endless moving means has ahorizontal flight 45 formed by thebelt 42 and the associatedguide 34, the belt mounted around twopulleys 46 at the sides of the machine frame to proceed as twoflights 48 towards asprocket 50 around which thechain 44 passes. The endless moving means overlap one another, as shown particularly in Figure 3, and the arrangement is such that each guide is aligned for unobstructed passage for its conductor pair as the pair moves along the feedpath. This clear passage for movement is achieved by disposing thehorizontal flights 45 of thebelts 42 of each group of position changing means at different vertical levels as shown by Figure 3. In practice, with the lower group, the horizontal flights are displaced progressively vertically upwards from one changing position to the next in the downstream direction of the feedpath by locating the pulleys upwardly from each position changing means to the next on supports 55 (see Figure 5). In contrast the horizontal flights of the upper group are displaced vertically downwards in a downstream direction of the feedpath. The horizontal flights of the two groups oppose each other across the feedpaths and approach each other progressively in a downstream direction. The advantages for this arrangement are as discussed in the aforementioned application. - Each of the endless moving means is movable independently of the others. For this reason, each position changing means is provided with its own reversible stepper motor 52 (see Figures 2, 3 and 7). All of the
stepper motors 52 are mounted remotely from the horizontal flights by being attached to upper andlower panels 54 of the machine stand. Each motor is directly drivably connected to asprocket 50 which engages with itsrespective chain 44 as shown by Figure 7. The drive motors may be driven at the same speed as each other whereby theguides 34 move along their horizontal flights at the same speed but out of phase with each other. However, in this embodiment the drive motors are driven at speeds which are slightly different from each other so that the positional relationship of all of the guides is continuously changing while reducing the possibility of a set pattern of movement of theguides 34. - A reversing means is provided for each
drive motor 52 to cause itsbelt 42 to reciprocate. As shown by Figure 7, and more clearly described in the aforementioned application, the reversing means for each direction of movement of abelt 42 comprises a magnet carried in one leg of ahead 58 which is U-shaped in side elevation (not shown). The other leg carries a magnetic field receiving means in the form of a coil (not shown) affected by inductance of the magnetic field created by the magnet. Each coil sends signals into an electrical circuit (not shown), the strength of the signals dependent upon the strength of the magnetic field induced in the coil and produced by the magnet. A trigger device in the form of anarm 60 is secured to and projects sideways from thechain 44 so as to be aligned with the gap in thehead 58. The position of the arm on the chain is dictated by the position required to influence the magnetic field, i.e. by a location within the gap when theguide 34 is at the end of its movement on the horizontal flight of its belt in the appropriate direction. - In use of the position changing means, the conductor pairs 10 are fed to their individual changing means 20 in the manner described with reference to Figure 1. Each conductor pair is passed through a
respective guide 34 and proceeds from there around two inseries arrangement rollers 62 prior to passing to the conductor unit array forming means. As the conductor pairs move along their feedpaths in spaced positions through the position changing means, theindependent motors 52 rotate at their own speed, possibly controlled by a computer, so as to move thebelts 42 to reciprocate the guides horizontally. During this movement, each of the conductor pairs passes both over and under horizontal flights of thebelts 42 of position changing means in its own group, as shown by Figure 2. In this figure, the paths of only six conductor pairs 10 are shown for clarity. Movement of theguides 34 independently of other guides continuously changes the relative positions of all of the conductor pairs as they pass through the position changing means. Thus as conductor pairs pass around thearrangement roller 62, their positions in the plane of contact with the rollers are dependent upon the positions of the pairs at any particular time moving through theguides 34. The relative lateral movement of conductor pairs will be discussed below. - While the position changing means is useful for producing positional change of conductor units in the finished core unit, any progression of conductor units around the axis of the core unit as they extend along its length is a random occurrence and takes place in a localized region. In the aforementioned EP-A-170352, the progression around the core unit was provided by a stranding machine in conventional fashion. In the apparatus of the present invention however, the stranding machine is replaced by the conductor unit array forming means 22 which simplifies the structure of the apparatus and also simplifies the reeling of cable core and removal of filled reels and their replacement.
- To be able to provide for any movement of each conductor unit around the core unit axis in progressive fashion, then the conductor unit array forming means must produce movement of each conductor pair not only in one plane as with the position changing means, but also in a second plane in a cross-section taken along the passline. To achieve this two planar movement of each conductor pair, the forming
means 22 operates to convert the planar arrangement of the conductor pairs as they issue from therollers 62 into a twoplanar array 72 in a section taken across the feedpath. Thus any lateral movement of any conductor pair as produced by the position changing means, will be translated into a movement across the array in two directions. - As can be seen from Figure 1 and more clearly from Figures 8 and 9, the array forming means comprises two
rollers roller 64 is disposed with its axis of rotation slightly upstream from that ofroller 66 with the rollers disposed one on each side of the passline. The outer peripheral surfaces of the two rollers vary in diameter along their axial lengths as shown by Figure 9. In the case ofroller 64, its outerperipheral surface 68 is of concave curvature whereas thesurface 70 ofroller 66 is convex. As is clearly seen from the figures, especially Figures 9 and 10, the rollers are disposed so that their surfaces while opposing one another do not in fact form a nip between them for the conductor pairs to be moved along the passline. In contrast, the rollers coact so that the surface of each roll urges the conductor pairs against the surface of the other roll as it passes between them so as to form acurved array 72 of the conductor pairs as they issue downstream from theroller 66. This curved array is in contrast to the flat array which exits from therollers 62 and, as can be seen from Figure 14 particularly, has two ends which turn upwardly. The spacing apart of therollers roller 64. In contrast, if the rollers had a relationship tending more towards a nip for passage of the conductor pairs, then movement of the pairs transversely of the array could not take place and also there might be a tendency for the conductor pairs to bunch together in between the rollers so as to follow a path of least resistance as they move towards the closing dies. - The
array 72 issuing from between therollers means 24 comprises an upstream profile die 74 withorifice 75 and a further profile die or dies 76 withorifice 77, these dies 74 and 76 which are for the purpose of guiding the conductor pairs in thearray 72 into a more closed position in which they are aligned with the closing die 16 which causes final convergence of the conductor pairs to form thecore unit 14. As may be seen from Figure 11, the two profile dieorifices orifice 78 so as to fill it without distorting some pairs more than others in the closing die orifice, it is essential that the profile dieorifices orifice 78. As a result of this, as the array of conductor pairs moves into the orifice ofdie 74, the upturned side portions of the array engage thesides 80 of the orifice with the center of the array engaging towards the bottom regions of the orifice. The conductor pairs at the upwardly turned side edges are then directed more towards the upper regions of the profile dieorifice 77 as these regions are lower than those of thedie orifice 75. Hence the conductor pairs move more towards the upper regions of the dies as they progress from one die to another until upon reaching the closing dieorifice 78, the conductor pairs engage around the whole of the peripheral surface of the circular die orifice in natural alignment with the orifice as they pass into it. The bunching together of conductor pairs at this stage, of course, ensures that thedie 78 is filled by the pairs. - As will now be described, the relative movement of the conductor pairs in the position changing means and the formation of the array in the array forming means causes the conductor pairs to follow a path around the axis of the core unit as the core unit is being formed. This progression of conductor pairs from position changing means and into the finished core unit will be described with reference to two pairs only. The action of these two pairs is typical of all other pairs passing through the apparatus and into the core unit.
- Figure 13 shows, as dots, the positions of all of the conductor pairs 10 at a specific time as they emerge from the position changing
means assembly 20. At that time, two of the conductor pairs 10a and 10b are inpositions conductor pair 10a having only just commenced movement in that direction and conductor pair 10b almost at the end of its movement before returning in the opposite direction. - At some later time, and with the conductor pairs moving laterally at different speeds,
conductor pair 10a has now reachedposition 84 towards the end of its movement towards the left. At this stage, conductor pair 10b has completed movement towards the left and is at someintermediate position 86 of movement towards the right. - The corresponding
positions array 72 and as they pass through the dies 74 and 76 are shown in Figures 14, 15 and 16. - The positions of conductor pairs in the array and as they pass through the profile dies 74 and 76 have some control over their position in the finished cable core unit. The final position of each of the pairs is, of course, also dependent upon the pressure applied to them in a lateral direction by other pairs as they approach and enter the closing die 18. Hence, not only is each pair moved progressively in one direction and then in the other around the axis of the core unit as it extends along the core unit, but also its radial position in the core unit is automatically determined. This is illustrated by the positional movement and the path followed by
conductor pairs 10a and 10b as they turn around the core unit axis along an axial length of the core unit. In Figure 17,conductor pair 10a follows thepath 88 around the core unit between the twopositions positions pair 10a substantially completes movement in one direction and almost one complete revolution around the core unit axis. - On the other hand, conductor pair 10b in completing one direction of movement and then commencing to move in the opposite direction between
positions limit position 90 in one direction as it moves alongpath 92 in Figure 17 between thecorresponding positions - As may be seen, it is impossible for any
conductor pair 10 to form a complete revolution about the cable core axis before changing direction of movement around the axis. Passage of the closed together conductors in the core unit through the bindinghead 18 effects wrapping of a binder tape in conventional manner around the core unit and holds it in substantially circular cross-sectional shape. - The above embodiment shows that with the use of apparatus and a method according to the invention, conductor pairs in a finished core unit may be caused to follow a path which extends around the axis of the core unit as the pairs move along the core unit and without use of a stranding machine. It follows that the core unit is provided with the degree of flexibility which is required to enable it to bend and without placing undue strain on the conductor pairs.
- As can be seen from Figure 1, after movement of the core unit through the binding head, it is reeled onto a
reel 94. Because the apparatus causes the conductor pairs to move around the axis of the core unit as described, there is no reason for thereel 94 to be rotated around any axis additional to its normalrotational axis 96. Thus thereel 94 is merely rotated around its own axis by amotor 98 and for this purpose may be merely held in bearings at its ends in a fixed position machine frame. It follows therefore that it is a simple matter to remove a filled reel and to replace it with an empty reel for a further reeling operation in a short space of time. In addition to this, and as shown by the modification of Figure 18, there may be two or more reels disposed side-by-side such asreels reel 94 being filled with core unit, then the core unit issuing from the closing die is fed onto thereel 100 without stopping operation. - In a second embodiment shown in Figure 19, the reels are dispensed with and the core unit after passage through the binding
head 18 is then passed through apparatus for completing manufacture of the cable with the core unit forming the whole cable core. The bound core unit is fed intoapparatus 102 for folding acore wrap 104 around the core unit and for placing a metal shield orsheath 106 onto the core unit prior to extruding a jacket around the unit by theextrusion head 108. The apparatus for providing the core wrap, sheath and jacket are of conventional construction and do not require description. - The possibility of applying a core wrap, sheath and jacket in tandem with core unit formation also makes it possible to tandemize the above operation with the twisting of individually insulated conductors into conductor pairs when incorporated with apparatus as described in U.S. Patent Application Serial No. 565,634 filed December 27, 1983 (Canadian Application 444,295, filed December 23, 1983) and entitled "Forming Cable Core Units" and in the names of J. Bouffard, A. Dumoulin and M. Seguin. As described in Application Serial No. 565,634, in the second embodiment of Figure 19, the reels of conductor pairs are replaced by a plurality of twisting
machines 110, i.e. one for eachconductor pair 10. Thesemachines 110 may be of conventional construction and each have two reels of individual insulated conductor. The two conductors of each machine are twisted together as they leave the machine. The twisted pairs then pass through a tension reducing means which enables the twisting machines to be placed in tandem with the core unit forming means. The tension reducing means comprises twocylinders cylinders - Hence, when there is a small tension in any pair downstream from the cylinders, the cylinders provide no assistance in drawing the
pairs 10 because the grip upon the cylinders is unsubstantial. If downstream tension increases, thereby increasing this grip, the cylinders provide a degree of assistance corresponding to the degree of grip. Of course, immediately this assistance is given, the downstream tension reduces thereby reducing the degree of grip and thus of cylinder assistance. The cylinders thus reduce the tensions downstream to enable the conductor pairs to be formed, at low tension, into the core unit. The operation of the tension reducing means which enables the twisting operation to be tandemized with the core unit forming process is described in detail in Application Serial No. 565,634. - It is clear therefore that the invention provides not only a core unit having conductor pairs extending around its center to provide the normal flexibility for a core unit, but also simplifies the operation of the apparatus, i.e. it enables reels to be replaced simply and quickly or it enables the core unit to be formed in tandem with the cable finishing processes. Clearly, greater core and cable flexibility is provided if each conductor pair extends around the core unit axis for almost a complete revolution. However, it is preferred that the movement around the core axis of each pair subtends an angle of at least 180° with the core unit axis. In particular, extremely good flexibility is obtained with the angle at least 270°. In addition to this, it is also clear that each conductor pair moves through the core unit completely independently of other conductor pairs and as dictated by the use of the position changing means in addition to the array forming means. Each conductor pair in fact follows a path around the core unit through inner and outer radial positions so as to lie close to any other conductor pair for only short distances of the core unit. Thus the apparatus provides improvements in the electrical characteristics such as in mutual capacitance or lowering the coefficient of deviation of mutual capacitance between the pairs and lessening outer pair capacitance unbalance. The independent movement of the conductor pairs throughout the core unit also leads to a reduction in cost.
Claims (8)
- Apparatus for forming a core unit from telecommunications conductor units each formed of twisted together insulated conductors, comprising in a downstream direction along a passline for the conductor units:-
a position changing means (20,30) for changing the positions of laterally spaced-apart conductor units (10) across the passline and relative to other conductor units (10);
conductor unit array forming means (22) comprising at least two rollers (64,66) having rotational axes one downstream from the other with opposed peripheral surfaces (68,70) of the rollers spaced apart one on each side of the passline, each surface changing in diameter along its length with one surface (70) having its smallest diameter and the other its largest diameter (68) at a position intermediate its axial ends, the positions and configurations of the surfaces being such that together they are operable to position the conductor units in an array as the conductor units move towards, past and then beyond the rollers, the array extending in two planes in a section taken across the passline, the rollers enabling the conductor units to move across the array dependent upon the positional change caused by the position changing means; and
a core unit forming means (24) comprising a closing die (16) for forming a core unit from the conductor units. - Apparatus according to claim 1, characterized in that the position changing means (20) is continuously operable to change position of each conductor unit laterally across the feedpath.
- Apparatus according to claim 1, characterized in that in side elevation, one of the rollers (68) has a concave peripheral surface and the other roller (70) has a convex peripheral surface.
- Apparatus according to claim 3, characterized in that the roller (70) with the convex peripheral surface is disposed downstream the roller (68).
- Apparatus according to claim 3 characterized in that the rollers are operable together to provide a curved array of conductor units with sides of the array extending upwardly from an intermediate region of the array, the closing die (16) has a die orifice (18) of substantially circular configuration, and the core unit forming means (24) also comprises a die (74) upstream from the closing die (16), the die (74) having an orifice (75) with greater height than width, and the die orifice (18) is smaller than the die orifice (75), the closing die (16) being disposed with a centre of its die orifice (18) disposed below the center of the die orifice (75) whereby the die orifice (75) is operable to guide conductor units engaging its upper side regions into engagement with the upper regions of the die orifice (18).
- A method for forming a core unit from telecommunications conductor units each formed of twisted together insulated conductors, comprising:-(a) moving a plurality of conductor units (10) in laterally spaced relationship along a passline while:
moving the laterally spaced conductor units (10) into an array (22) across the passline, the array of controlled configuration extending in two planes in a section taken across the passline; and
moving each conductor unit alternately in opposite directions across the passline independently of other units at a position upstream from the array so that each conductor unit moves alternately in opposite directions across the array and the conductor units move laterally relative to one another in the array (22); and(b) causing the conductor units in the array to converge as they continue along the passline so as to bring them together to form the core unit with the relative positions of the conductor units changing in the core unit as influenced by their relative positions in the array (22) and with each conductor unit moving around the axis of the core unit alternately in opposite directions as it moves along the core unit as influenced by its movement across the array. - A method according to claim 6, characterized in changing the relative positions of the conductor units (10) in continuous manner upstream from the array (22) whereby, in the core unit, the relative positions of the conductor units change in a continuous manner.
- A method according to claim 7, characterized in moving some at least of the conductor units so that they move across the array alternately in one direction and then in the other a sufficient distance to cause said conductor units to move alternately around the core unit in opposite directions while subtending an angle greater than 270° from the axis of the core unit for each direction of movement around the axis.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CA482544 | 1985-05-28 | ||
CA000482544A CA1235288A (en) | 1985-05-28 | 1985-05-28 | Manufacture of telecommunications cable core units |
Publications (3)
Publication Number | Publication Date |
---|---|
EP0207612A2 EP0207612A2 (en) | 1987-01-07 |
EP0207612A3 EP0207612A3 (en) | 1988-12-28 |
EP0207612B1 true EP0207612B1 (en) | 1992-01-29 |
Family
ID=4130574
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP19860303803 Expired EP0207612B1 (en) | 1985-05-28 | 1986-05-19 | Manufacture of telecommunications cable core units |
Country Status (4)
Country | Link |
---|---|
EP (1) | EP0207612B1 (en) |
CA (1) | CA1235288A (en) |
DE (1) | DE3683696D1 (en) |
FI (1) | FI862243A (en) |
Family Cites Families (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB1490532A (en) * | 1974-09-19 | 1977-11-02 | Standard Telephones Cables Ltd | Apparatus for manufacturing telecommunication cable |
FR2488437A1 (en) * | 1980-08-05 | 1982-02-12 | Cables De Lyon Geoffroy Delore | Random core mixing appts. for electrical cable - includes oscillating slotted disc carrying cores of cable ensuring random relative positions of cable cores to eliminate cross-talk |
CA1239278A (en) * | 1984-07-27 | 1988-07-19 | John N. Garner | Manufacture of telecommunications cable core units |
-
1985
- 1985-05-28 CA CA000482544A patent/CA1235288A/en not_active Expired
-
1986
- 1986-05-19 EP EP19860303803 patent/EP0207612B1/en not_active Expired
- 1986-05-19 DE DE8686303803T patent/DE3683696D1/en not_active Expired - Fee Related
- 1986-05-27 FI FI862243A patent/FI862243A/en not_active IP Right Cessation
Also Published As
Publication number | Publication date |
---|---|
DE3683696D1 (en) | 1992-03-12 |
EP0207612A3 (en) | 1988-12-28 |
FI862243A0 (en) | 1986-05-27 |
CA1235288A (en) | 1988-04-19 |
EP0207612A2 (en) | 1987-01-07 |
FI862243A (en) | 1986-11-29 |
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