GB1288924A - - Google Patents

Abstract

1288924 Cable armourings COMPAGNIE FRANCAISE THOMSON HOUSTON-HOTCHKISS BRANDT 13 Nov 1969 [14 Nov 1968 7 Feb 1969 28 March 1969] 55742/69 Heading H1A [Also in Division B8] An electric cable comprises a central assembly 2 of insulated conductors surrounded by a concentric metal conductor or armouring 3 constituted by one or more metal strips (Figs. 3-9, not shown) provided with perforations in the form of holes, slots or slits at least some of which are formed in the edges of each strip. The armouring or conductor 3 may be of a tubular sheath wound around its longitudinal axis as shown or of several metal strips (105, Fig. 11, not shown) arranged with their longitudinal edges overlapping or arranged in super-imposed layers (136-139, Fig. 14, not shown) and staggered. The metal strips may be provided with covering sheets 4, 5 of an adhesive plastics material of greater width. The slits or slots may have a depth equal to three-quarters of the width of the strip and a spacing of one-third the width. A process for making the cable as shown in Fig. 13 comprises the steps of twisting the individual conductors 102 at a fixed die 113 to form the central assembly, of applying metal strips 105 around the assembly according to a comparatively long pitch to form the armouring and of winding ribbons 106 around the composite of assembly and strips which is displaced by a drawing caterpillar 114 towards a storage reel 116. An outer protective sheath may be applied if desired and the cable may be non-sealed or sealed by a foam or any sealing compound. The apparatus of Fig. 10 (not shown) includes an arrangement for pre-forming the perforations in the metal strips used for the armouring and of applying adhesive plastics layers on either side of the strips.