GB398811A - Improvements in the insulation and construction of electric cables, wires and conductors - Google Patents

Abstract

398,811. Cables. GREENGATE & IRWELL RUBBER CO., Ltd. and POVEY, R., Greengate, Salford, Manchester. March 19, 1932, No. 8215. [Class 36.] Cables are insulated with layers of unvulcanizable wax compound containing at least 50 per cent of wax alternating with layers of varnished fabric or fabric proofed with the wax compound, the innermost layer of the insulation being of the wax compound and applied directly upon the conductor or upon an interposed layer of asbestos. The outer layer of insulation, which is of varnished or proofed fabric, is covered by a braided fabric sheath coated with cellulose varnish or wax, over which may be applied a protective metal sheath. The wax compound, which may be extruded on the conductor or which may be spirally wound on the conductor in strip form, comprises a mixture of paraffin, ozokerite or ceresin with rubber, guttapercha or balata without vulcanizing agents, the wax comprising from 50 to 80 per cent of the mixture. The Figure shows a conductor A having insulating layers a, a<1> of wax compound and layers b, bl of varnished or proofed fabric. A braided cotton layer d which is treated with wax or cellulose varnish, and which may be armoured with metal, completes the cable. The layers a<1>, b<1> may be applied in one operation by coating the proofed fabric with the wax compound before it is lapped on the conductor.