GB1241360A - Method of applying a protective covering to a cable - Google Patents

Abstract

1,241,360. Electric couplings &c. SIEMENS A.G. 16 Oct., 1969 [28 Feb.; 1969], No. 50948/69. Heading H2E. One or more tapes of an olefinic copolymer of at least two olefins are wound on the end of a polyolefin insulated cable, and are then crosslinked or vulcanized to form an integral body chemically bonded to the polyolefin insulation and able to withstand the rated voltage of the cable during continuous operation. Two single conductor cables 1, with either crosslinked, or high or low pressure. polyethylene insulation 3, and conductor smoothing layer 4, conductive varnish layer 5, textile tape 6, screening 7, and sheathing 8 are joined by soldering to a jointing sleeve 10. Weakly conducting tapes 11 of ethylene-propylene-terpolymer are wound on sleeve 10 and cover layer 4 on each cable. Tapes of ethylene-propylene-terpolymer are wound over tapes 11 and insulations 3 to form a sleeve, and all the copolymer is crosslinked or vulcanized by heat, and possibly also pressure so that an integral body chemically bonded to the insulations 3 is formed. To effect dross.linking a peroxide may be employed, or must be employed for an ethylene-propylene elastomer, and for vulcanizing, a mixture of sulphur and an organic accelerator, for example mercaptobenzthiazole or tetrainethylthiuram disulphide. A layer of varnish, united with varnish 5 of the cables is applied, and a conductive tape 13, copper strip 14, and plastics tape 15. An epoxy resin body 16 is cast around the joint, or (Fig. 2, not shown) a polyvinyl chloride tube (17) is shrunk on to it; The copolymer may be ethylene-olefin copolymer, or an ethylene propylene elastomei, or may contain as a third component a polyunsaturated hydrocarbon, e.g. a diene.