Patent GB-1008426-A (GB)
Title: Improvements relating to communications cables
IPC: H01B11/04
Filed: 1962-10-01
Abstract: 1,008,426. Cables. SIEMENS & HALSKE A.G. Oct. 1, 1962 [Sept. 29, 1961], No.37023/62. Heading H1A. A communications cable comprises a stranded layer of single wires totalling a multiple of eight in number, the multiplier being at least two, wherein the paths of each four single wires which are disposed one with respect to the next at 90 degrees circumferential intervals in the layer, referred to as " quads " or " fourphantom lines " in the Specification, do not cross one another, and wherein a series of wire crossings are arranged at crossing points spaced at intervals along the cable so that in traversing the series the path of each odd-numbered wire in the layer (Figs. 1 and 2) crosses the path of each even-numbered wire in the layer, the paths of the odd-numbered wires which are not disposed in the same quad cross one another, and the paths of the even-numbered wires which are not disposed in the same quad cross one another. Fig. 2, which is an isometric projection of the arrangement of wires shown in Fig. 1, shows the crossing arrangement for a sixteenwire layer making available 14 decoupled lines. Proceeding along the cable, similar successions of single wire crossing points G are provided each followed by a multiple-wire crossing point Z at which groups of two neighbouring wires are crossed with a neighbouring like group. Each succession of single-wire crossing points consists of n.4 crossing points, n being a selected whole number, in this embodiment unity. This sequence of wire crossings is repeated successively and after four such sequences, each being displaced 45 degrees with respect to the preceding one, the sixteen wires have the same numerical sequence as at the start and the wires are completely decoupled, each odd-numbered wire having crossed each even-numbered wire, the paths of the odd-numbered wires which are not disposed in the same quad having crossed one another, and the paths of the even-numbered wires which are not disposed in the same quad having crossed one another. Eight trunk lines (each formed by diametrically opposite wires), four four-phantom lines and two eight-phantom lines (each formed by two four-phantom lines) are obtained with this arrangement. The Specification describes the series of wire crossings for 24 and 32 single wire layers and for a 16-wire layer with n = 2 (Fig. 3, not shown). Where the number of wires in the layer is divisible by 32, a further multiple-wire crossing point is incorporated at which groups of four neighbouring wires are each mutually crossed with a like group (Fig. 7, not shown). Where the number of wires in the layer is divisible by 24, each succession of single-wire crossing points consists of n.3 crossing points, and at each multiple-wire crossing point between adjacent group crossings two neighbouring wires remain uncrossed, and at the next succeeding multiple-wire crossing point along the cable those uncrossed wires are included in group crossings whilst wires included in group crossings at the preceding multiplewire crossing point are excluded and form the wires that remain uncrossed (Fig. 5, not shown). The wire crossing points are arranged to effect relative displacements between mutually adjacent trunk lines and four-phantom lines in opposed circumferential directions of the layer and through different angles, the displacement angles being in the ratio of Œ1: Œ3 for 16 wires, Fig. 2, Œ1 : Œ2 : Œ3 for 24 wires (Fig. 5, not shown) and Œ1 : Œ3 : Œ5 : Œ7 for 32 wires (Fig 7, not shown).