| 摘要 |
1,272,355. Cable. KABEL-UND METALLWERKE GUTEHOFFNUNGSHUTTE A.G. 7 Aug., 1970 [8 Aug., 1969], No. 38216/70. Heading H1A. A cable has soft aluminium phase conductors 1 surrounded by a casing 2 of a thermoplastic synthetic resin which is enclosed in a layer 3 of flexible material in which are embedded aluminium wires 5 and copper wires 6 forming the neutral conductor, the wires of the neutral conductor being applied with their direction of lay being reversed periodically along the cable. This is surrounded by a helical metal band 7 to ensure a uniform distribution of current between the wires 5, 6 and a casing 4 of a thermoplastic synthetic resin, e.g. polyvinyl chloride, is formed around the cable. The aluminium and copper wires, 5, 6 may be tinned and the sum of the cross-sections of all the copper wires may be greater than the cross-section of a fuse protecting the cable. The neutral conductor wires may alternatively each be formed by a copper wire sheathed in aluminium, the aluminium sheath being either pressed on to the copper wire by means of an extruder or shaped around the copper wire as a longitudinal strip the edges of which are welded together after this shaping. The neutral conductor wires may alternatively each be formed by an aluminium wire sheathed in copper, the copper sheath being applied by electrolytic means or by a copper strip shaped longitudinally around the aluminium wire, the strip edges being welded together by electric arc welding using a protective gas. Instead of using aluminium in the neutral conductor iron, iron alloys, or ferrous metals in general may be used. The phase conductors 1 may consist of aluminium wires pressed into the form of segment-shaped conductors. |
