GB698545A - Improvements in or relating to the manufacture of electric cables - Google Patents

Abstract

698,545. Cables. DERBY CABLES, Ltd. June 15, 1950, No. 14925/50. Addition to 644,530, [Group V]. Class 36. [Also in Group V] The parent Specification describes a method and an apparatus in which conductors or cores are passed through an apparatus for extruding rubber or plastic composition, each conductor passing through a channel in a revolving pointholder, whereby the conductors are spacedly arranged in the cable. In the present invention, to ensure that the conductors shall be properly spaced in the rubber &c., a helical winding or helix of rubber, rubber-like material, strip metal, textile cord, wire covered with rubber or rubberlike material, or other flexible and sufficiently non-compressible material is tightly applied to one or more of the conductors prior to entry of the conductors into the extruding apparatus. In section, the helix may be circular or square. Fig. 1 shows a power conductor b, insulated with rubber, plastic, &c. b<SP>1</SP>, which is to be passed through the extruding apparatus, this conductor having a tightly wound helix a of rubber &c. Fig. 3 shows a multi-core cable comprising four insulated power conductors b surrounding a bare earthing conductor c having a helix a tightly disposed thereon. Fig. 5 shows a cable similar to that of Fig. 3, but in this case helices a are provided only on the insulated power conductors b, which are thereby spaced from the bare earthing conductor a. In Figs. 3 and 5, c is rubber or plastic material that surrounds all the conductors and fills the spaces therebetween.