GB928712A - Electric cable comprising an external metal sheath - Google Patents

Abstract

928,712. Cables. COMPAGNIE GENERALE D'ELECTRICITE. Jan. 31, 1962 [Feb. 2, 1961], No. 3639/62. Class 36. An electric cable with metallic sheath is provided with an intercalary insulating cord or tape wound between the insulated core and the sheath of the cable to avoid damage to the insulation during application of the sheath at high temperatures. As shown, Fig. 1, the cable core consists of a number of insulated conductors 1 and is surrounded by further insulation 3 wound in the form of tapes. The intercalary element around the insulation 3 is in the form of a helically wound cord of a material such as nylon, polypropylene or a cellular plastic material, of high thermal resistance. The metal sheath 6 is arranged on the intercalary element, the helical air gap 5 between the sheath 6 and the insulation 3 decreasing the effect of the heated sheath on the insulation 3. If desired, the insulation may be a cord wound around the cable core. Fig. 3 shows a coaxial cable of which the outer conductor comprises the sheath itself, the inner conductor being spaced from the insulating tape 3 by circular spacers 2. Insulating cord 4 separates insulation 3 from sheath 6. The insulation may be omitted and two parallel cords laid directly on the spacers 2. The insulating intercalary elements may be tapes instead of cords having each a longitudinal ridge 7 or bead 8 or sheets folded longitudinally to cover the insulation 3 and having oblique corrugations 9 or multiple ridges 10, on the surface facing the sheath to provide air spaces for heat dissipation (Figs. 5-9, not shown).