GB547470A - Improvements in electric cables - Google Patents

Abstract

547,470. Electric cables. CALLENDER'S CABLE & CONSTRUCTION CO., Ltd., and HUNTER, P. V. April 10, 1941, No. 4798. [Class 36] A cable with the insulation impregnated with a liquid, such as mineral oil or compound, and enclosed in a sheath, the body of the cable is built up of solid parts which fit together closely to leave a minimum space for the impregnant and give the body a non- circular cross-section, and the sheath consists of a strip of elastic metal, such as steel, iron, bronze or hard copper, wrapped closely round the body and connected at the seam as by welding. In Fig. 2, the stranded conductor 1 and layers of impregnated paper 2 are surrounded by a helical wrapping 3 of perforated metallized paper or other screening material, about which are placed packing members 4 to give an approximately triangular section ; members 4 may be of jute strings impregnated with oil or compound and are pressed tightly together and on to the wrapping 3 by the sheath 5 comprising a strip of elastic metal wrapped round the composite body longitudinally and having its flanged edges 6 connected by brazing metal 7. In Fig. 3, the sheath comprises a strip of metal wound helically and with its flanged edges 6 welded or brazed, the strip having two corrugations 8 parallel to its length. In Fig. 6, the cable comprises three cores as in Fig. 1 (not shown) laid together helically, and with a further packing member 4 in the central space.