GB356376A - Improvements in or relating to telephone and like electric cables - Google Patents

Abstract

356,376. Telephone cables. HACKETHAL-DRAHT - UND KABEL - WERKE AKT.-GES., Staderlandstrasse, Hanover, Germany. July 10, 1930, No. 20972. Convention date, July 10, 1929. [Class 36.] To compensate the pair to phantom cross-talk couplings in a telephone quad, a length of the quad is so stranded that only one core of one pair of conductors 2, Fig. 2, E, is maintained adjacent the other pair 1. During the stranding of the compensating length the twist of the pair 2 is stopped, but the natural twist of the pair 1 and the lay of the quad is preferably continued. A fractional part of a run of cable, such as one of a number of lengths in series, may be formed as above with couplings which compensate for the total couplings of the remainder of the run, but preferably the couplings of each length are measured continously on the stranding machine and compensation is set into operation as soon as the couplings reach a predetermined value. To avoid the formation of pair to pair couplings due to the pair 2 of the compensating length being distorted into an oblique position, as shown at G, Fig. 2, the pair 2 is oscillated between the positions A, B through E. Fig. 1 shows a stranding machine for carrying out the invention; each pair of heads a, band c, d carrying core spools run round each other to strand the cores to pairs, whilst both pairs of heads rotate about a common axis to give the quad stranding. A predetermined location of the cores in the stranding nipple e and thus in the quad is obtained by passing the cores through adjustable guides f, g, between the heads and the stranding nipple, the guides being normally in positive connection with the heads belonging to the same pair, but may be moved independently by devices h, i. The pairs of heads a, band c, d may be locked in any position in relation to the whole system in order that the twisting of a pair of cores may be stopped when it is desired to set the compensation into operation. To prevent displacement of the cores with reference to each other, the pairs before quadding and the quad after stranding may be wound with paper strips or threads.