GB268418A - Improvements in or relating to electric cables - Google Patents

Abstract

268,418. Macintosh Cable Co., Ltd., and Williams, A. W. Dec. 23, 1925. Cores for cables; cables, arrangement and disposition of parts of; cables with auxiliary conductors.- Relates to cables such as those used for supplying electrical apparatus in mines, of the kind comprising a plurality of cores embedded in rubber &c. insulating material. and consists in providing the cores with a conducting sheath consisting of wire cords each composed of a group of spirally twisted strands, the cords being helically twisted in one direction about the cores in such a manner as to lie close together without crossing. Fig. 1 shows a cable comprising three power cores 1 arranged symmetrically about a central earthing core 2. All the cores are similarly constructed and consist of a central conductor 4, Fig. II, insulation 5 and a sheathing of helically wound conducting cords 6 each formed of a number of helically twisted wires. The sheathings of the power cores are in electrical contact with the sheathing of the earth core or with a bare earthing conductor 11 as in Fig. V. Cushioning pads may be interposed between the power cores and one of the pads may carry at its outer edge an earthing conductor 12. Fig. IV shows an arrangement in which the power cores 1 and the earthing conductor 8 wrapped with insulation 9 to enlarge it to the size of the power cores are supported and spaced by a pad 10 of cross shape. The Provisional Specification refers to Specification 209,831, [Class 38 (v), Electric switches &c.].