IE65284B1 - Improvements in or relating to cable manufacture - Google Patents

Description

IMPROVEMENTS IN OR RELATING TO CABLE MANUFACTURE This invention relates to the manufacture of cables.

In the manufacture of cables, the cable is generally made up of concentric layers of a defined maximum number of strands which are wrapped around a central strand e.g. 1+6,+12,+ 18 etc. The outer strands are wrapped around the inner strands in multiple groups so that, for example, in the case of a cable made up of two hundred pairs of wires a central core made up of fifty pairs is passed through a cable production line and six groups of twenty five pairs are wrapped around the central core of fifty pairs to make up the finished cable of two hundred pairs. Such a cable is used in telecommunications and the process generally requires two passes through the production line.

The first pass comprises the manufacture of the central core of fifty pairs which is made up of two bunches of twelve pairs and two bunches of thirteen pairs wrapped about each other to form the fifty pair core. The second pass comprises passing the fifty pair core through the production line and the twisting and wrapping of the external six sets of twenty five pairs about the central fifty pair core to make the finished two hundred pair cable.

Two passes through a production line are also required for the - 2 manufacture of other cables such as a three hundred pair cable which is made up of a one hundred pair core around which eight groups of twenty five pairs are wrapped, also 400 pair which is made up of one hundred pair around which six groups of fifty pairs are wrapped.

Cable manufacturing methods which require more than a single pass through the production line are time consuming and hence result in an increase in manufacturing costs. Therefore, single pass cable manufacturing processes are preferable as production speeds are increased and manufacturing costs reduced concomitantly.

An object of the invention is to provide a production line and process for use in the manufacture of cables in which a single pass is required through the production line.

According to the invention there is provided a production line apparatus for the manufacture of cables comprising: a plurality of binders for binding one each of a plurality of 20 groups of wires; positioning means for positioning the groups of wires; a closing die for converging the groups of wires; twisting means for twisting the converged wires into a cable, and a drum for receiving the twisted cable, the production line being further provided with a secondary positioning means and secondary closing die to position and converge a central core group of wires and secondary binding means to bind the converged core group of wires so that the core cable can be manufactured and the groups of wires twisted around the core cable simultaneously in a single pass through the apparatus, the plurality of binders and the secondary binder being mutually arranged so that the bound groups of wires are wound symmetrically relative to one another about the core cable. - 3 The invention also provides a process for the manufacture of a cable comprising twisting groups of individual cables around a central core group of wires wherein the central core group of wires is assembled before the twisting operation and simultaneously with the twisting operation in a production line.

An embodiment of the invention will now be described having regard to the accompanying drawings in which: Figure 1 is a side elevation of a production line of the prior art; Figure 2 is a top elevation of the production line of Figure 1, and Figure 3 is a side elevation of the modified portion of a production line of the invention.

As shown in Figures 1 and 2, a production line apparatus 1 of the prior art has a number of components. The first component is a binder frame 2 into which individual groups of wires which contribute to make up the finished cable are fed from pay off drums (not shown). The binder frame 2 is followed by a table 3. A series of taping heads 6 follows the table 3, followed by a capstan haul off 7, a traverse 8 and take up drum 9. The drum 9 is motorised so that the cable is taken up from the capstan haul off and wrapped around the take up drum 9.

The binder frame 2 has a base 10 on which an outer support frame 11 and an inner support frame 12 are mounted. A series of input pulleys 13 and guides are mounted on the outer face of the outer frame 11. The pulleys 13 receive the groups of wires which make up the finished cable from the pay off drums. A corresponding number of binders 14 are mounted on the inner face of the outer frame 11. The binders 14 contain binding material which is wrapped around each of the groups of wires pulled through the binders 14 from the pul lies 13. The inner frame 12 has a number of pulleys 15 mounted on its outer face. The pulleys 15 receive the bound groups of wires from - 4 the binders 14. The table 3 has a lay plate 4 and a closing die 5 mounted on its top surface. f The lay plate 4 and closing die 5 are mounted on the table 3 so that the lay plate 4 is closest to the binder frame 2. Binded wires • are passed through the lay plate 4 from the binding frame 2 and converge at the closing die 5 to form a symmetrical shape.

Taping heads 6 follow and are used to form a tightly controlled cable assembly. Capstan 7 is made up of a number of capstan wheels. The converged groups of wires are twisted by passing them through the capstan wheel sequence.

The capstan wheels 7 are mounted on a carriage 16. The capstan wheels 7 contribute to imparting a twist to and controlling the tension on a cable passed over the wheels. The capstan wheels 7 are mounted on the carriage 16 immediately preceding the traverse 8; also mounted on the carriage 16.

The take up drum 9 is rotatable and is mounted on a disc supported by underrollers on carriage 16 and is the final component in the production line 1. The take up drum 9 is driven by a motor (not shown) and pulls the cable and groups of wires along the production line 1 in a tension controlled condition.

In the production of a cable made up of for example two hundred pairs of wires, the production line 1 can be used. Such a two hundred pair cable is made up of a central core group of wires made up of fifty pairs and six outer groups each of which is made up of twenty five pairs of wires. The six outer groups of twenty five pairs are wrapped around the central group of fifty pairs and twisted in the production line 1 to make up the two hundred pair cable.

* However, the central group made up of fifty pairs must first be * 35 manufactured by passing two groups, each made up of twelve pairs, and two groups, each made up of thirteen pairs, through a production line. Therefore, the manufacture of a two hundred pair cable using the apparatus described above requires two passes through a - 5 production line. In such a production line, the central group of fifty pairs of wires is fed from a pay off drum (not shown) onto a pulley 13. Six groups of twenty five pairs of wires per group are also fed onto an input pulley 13 from input drums (also not shown). All groups are then passed from the input pulleys 13 through openings provided therefor in the outer frame 11 into the binders 14. The binders 14 bind each of the groups which are then passed through the inner frame 12 of the binder frame 2 onto the pulleys 15 and twisted as described above.

Figure 3 shows an enlarged side elevation of a modified portion of a production line 20 of the invention. The remainder of the production line comprises the components described above.

The modified portion 18 is made up of a modified support frame of the binder frame 2 and an external table 19. The external table resembles the inner table 3 but is positioned in the production line 20 before the outer frame 11 so that the tables 19 and 3 are mounted either side of the binder frame.

The external table 19 has a lay plate 21 and a closing die 22 mounted on its top surface in an arrangement similar to that on the internal table 3. The closing die 22 is mounted between the lay plate 21 and the outer frame 11.

The outer frame 11 is provided with binders 14 on its internal surface for binding groups of wires received from pay off drums (not shown) as described previously. However, the outer frame 11 is provided with an additional central binder 23 on its internal surface for binding a core group of wires. The core group of wires is passed to the additional binder 23 through an opening 24 in the outer frame 11.

The additional binder 23 is driven by the twisting binder motor through additional drive pulleys 25 mounted on the external surface of the outer frame 11. The binder drive 25 is made up of an upper drive wheel 26 and a lower drive wheel 27 connected by a drive belt 28. When the upper drive wheel 26 is actuated, the lower wheel 27 is therefore rotated by the drive belt 28.

The lower drive wheel 27 and the upper drive wheel 26 are both mounted on drive shafts 29, 30 respectively which project from the outer frame 11. The lower shaft 29 is hollow and the lower drive wheel 27 is provided with an opening 31 which communicates with the hollow shaft 29 so that the core group of wires can be passed through the lower drive wheel 27, the shaft 29, the opening 24 and into and out of the additional central binder 23 where it is bound.

The lower drive wheel opening 31, hollow shaft 29, opening 24 and binder 23 are all co-axial so that the core group of wires travels in a straight line. The additional binder 23 is further located on the outer frame 11 so that the other binders 14 are distributed evenly about the additional binder 23. The opening of the closing die 22 is also co-axial with the shaft 29, opening 24 and binder 23.

The operation and use of the invention will now be described having regard to the accompanying drawings.

In the manufacture of a telephone cable made up of 200 wire pairs, a central core of wires made up of 50 pairs is used and six groups of 25 pairs are twisted about the central core as previously described. In the production line 1 the central core is pre-manufactured by a pass through the production line of the prior art of two groups of 13 pairs each and two groups of 12 pairs each.

In the production line 20, two groups of 12 pairs of wires and two groups of 13 pairs of wires are paid off from pay off drums (not shown) and gathered at the lay plate 21. The lay plate 21 has evenly arranged openings through which each group passes so that the groups of wires are evenly spaced apart. The groups of wires are illustrated schematically by broken lines in Figure 3.

The four groups of wires are converged at the closing die 22 to make a cable core of 50 pairs which is passed through the closing die 22, the opening 31 of the lower drive wheel 27, the hollow shaft 29, - 7 and the opening 24 in the outer frame 11 into the additional binder 23 where the central group of 50 pairs of wire is bound. The bound group of 50 pairs of wires is then passed through a central opening provided in the lay plate 4 and into the closing die 5. The six groups of 25 pairs of wires, also indicated by broken lines are also passed through the lay plate 4 from the binders 14 as described above. The six groups of 25 pairs of wires are arranged symmetrically about the central core of 50 wire pairs and the cable twisted and completed on this remainder of the production line 20 as outlined above.

The use of the external table 19 with the lay plate 21 and closing die 22, and the additional driven binder 23 therefore facilitates simultaneous production of the central core of wire pairs and the completed cable in a single pass through the production line 20 compared to the double pass required in order to first manufacture the core group of wires with the production lines of the prior art.

For 400 pair cables formed by six fifty pair groups around a central 100 pair group this is normally a three pass operation but with the new method described above the 100 pair group made from four 25 pair units are cabled together with the six 50 pair units; the 50 pair units having been formed individually as per the original method. Thus only two passes are necessary.

Claims (5)

1. A production line for the manufacture of cables comprising: a plurality of binders for binding one each of a plurality of groups of wires. positioning means for positioning the groups of wires; a closing die for converging the groups of wires; and twisting means for twisting the converged wires into a cable; and a drum for receiving the twisted cable, the production line being further provided with a secondary positioning means and secondary closing die to position and converge 20 a central core cable and secondary binder to bind the converged core cable so that the core cable can be manufactured and the groups of wires wrapped around the core cable simultaneously so that only one pass is required through the production line, the plurality of binders and the secondary binder being mutually arranged so that the 25 bound groups of wires are wound symmetrically relative to one another about the core cable.

2. A process for the manufacture of a cable comprising twisting groups of individual cables around a central core cable wherein the 30 central core cable is assembled before the twisting operation and simultaneously with the twisting operation in a production line as defined in claim 1.

3. A production line substantially as hereinbefore described with 35 reference to the accompanying drawings.

4. A process for the manufacture of a cable substantially as hereinbefore described with reference to the accompanying drawings. - 9

5. A cable whenever manufactured by a process as claimed in claim 2 or 4.