GB629923A - Improvements in or relating to electric cables - Google Patents

Abstract

629,923. Cables. POOLE, R. Dec. 4, 1947, No. 32078. [Class 36] An electric cable of the type made by drawing down an initial workpiece containing a block of pulverulent insulating material and conducting cores, has one or more parts of the insulating material distinctively coloured. The insulation may be made up of a plurality of differently coloured segments A, B, C, Fig. 2, in which the conductors E, El, E<SP>2</SP> are inserted. The assembly is surrounded with a metal sheath D and drawn down to the required diameter. Alternatively the insulation may comprise a block F, Fig. 4, provided with a plurality of groove-like recesses into which distinctively coloured insulating members G, G<SP>1</SP> G<SP>2</SP> may be inserted prior to the drawing down. A single asymmetrical gtoove may be formed in the insulating block for the insertion of a suitably coloured member (Figs. 6 and 8, not shown). The insulating material used is preferably magnesium oxide, a silicon compound, barium oxide or cadmium oxide, and may be coloured with any suitable insulating dye or oxide such as nickel oxide, cobalt oxide, lead oxides, or mercuric oxide.