GB677656A - Improvements in or relating to electrostatic screening conduits for electric conductors - Google Patents

Abstract

677,656. Conduits; screened cables; couplings. AVICA EQUIPMENT, Ltd., and MILLAR, J. H. March 6, 1951 [March 9, 1950], No. 5969/50. Classes 36 and 38 (i). [Also in Group XXVIII] A flexible electrostatic screening and protective conduit for electric cables, particularly those used in ignition systems, comprises a metallically reinforced flexible moisture-proof insulating tube 1 having an electrostatic screen 3 formed of strip metal foil wound therearound with successive turns overlapping one another. The reinforcement 2 may comprise high tensile strength wire braided around the tube 1, and a secondary braided metallic sheath 4 may be applied over the screen to serve as a secondary screen and also to hold the screen 3 in place and give additional reinforcement. The assembly may be encased in an insulating sheath 5. Several layers of foil may be employed, either applied directly over each other, or having additional braided layers therebetween. In order to apply a union to the end of the conduit the ends of tubes 1 and 5 are removed leaving bared metal 9. A ferrule 11 containing a deformable metallic band 13 is mounted on the end of the conduit so that annular teeth 12 are over the end of sheath 5. A tubular spigot 8 carrying a union nut 6 is inserted within the conduit to bring annular teeth 10 into engagement with tube 1. The ferrule 11 and spigot 8 are then closed together, as by swaging, causing band 13 to grip the bared metal 9. The spigot 8 and ferrule 11 are provided with collar 15 and groove 16 respectively which engage and prevent relative axial movement of the parts, the extremity of the bared metal 9 being trapped therebetween.