GB498888A - Improvements in or relating to electric cables - Google Patents

Abstract

498,888. Cables. PYROTENAX, Ltd., and BECKETT, C. M. July 14, 1937, No. 19562. Drawings to Specification. [Class 36] A cable of the kind manufactured by a drawing, rolling, or other mechanical lengthening treatment of a work-piece comprising a plurality of conducting cores separated from a surrounding metallic sheath by insulating- rnaterial such as powdered magnesia is provided with at least one datum core or mark visible at all cross-sections of the cable so that the individual conductors can be readily distinguished from one another by reference to the datum core or mark. One or more of the conductors may be of a different size, shape, or material from the other conductor or conductors, and conductors of similar shape, size and material may be distinguished from one another by their disposition relatively to a conductor of different size, shape, or material. Alternatively, the conductors may be asymmetrically arranged in the sheath, or the sheath may be of irregular form, the conductors being identified in the latter case by reference to the sheath. A datum core, which may or may not carry current, or a datum mark in the sheath, such as a longitudinal groove, may be provided when the conductors are symmetrically arranged in the sheath, the datum, core or mark being so disposed that it is nearer one conductor than any other. Specifications 471,935 and 472,159 are referred to.