GB485400A - Improvements in and relating to air-space-insulated high frequency electric cables - Google Patents

Abstract

485,400. Cables. SIEMENS & HALSKE AKT.-GES. Dec. 14, 1936. Nos. 34294 and 34295. Convention dates, Dec. 13, 1935 and Jan. 15, 1936. [Class 36] In an air-space insulated cable comprising one or more inner conductors 10, Fig. 1, spaced by members of polystyrol or other substantially non-compressible insulating material from an outer conductor or screen 16 formed of strips 16 which fit together to form a tube but which are liable to relative movement when subjected to internal pressure by the spacing members, either the spacing members are formed so as to possess a limited amount of fiexibility, or a yielding layer or skin is arranged between the spacing members and the outer conductor or screen to prevent relative displacement of the strips thereof. As shown in Fig. 1, the spacing members comprise polystyrol strings 11, 12 over which are wound polystyrol bands 13, 14 rendered flexible by rows of punched out bosses 15. The bosses may be staggered and the bosses in each row may be pressed out alternately on one and then the other face of the band. In the construction shown in Fig. 7, the spacer 35 between the inner and outer conductors 34, 38 consists of a multiply helical polystyrol cord 35 wound round the inner conductor and secured thereto by a binding 36. A reinforcing thread may run through the helical cord, the turns of the cord being bound to the thread. The individual plies of the cord 35 may be of round or sector-shape crosssection. In another construction, the inner and outer conductors are separated by ceramic discs arranged at intervals along the inner conductor, the periphery of each disc being coated with rubber. In a modified construction, similar to that of Fig. 1, the bands 13, 14 are replaced by a single unbossed band winding over which is wound in open turns a rubber thread. Specification 347,929 is referred to.