CABLES

摘要

1283271 Expanding conductor coatings STANDARD TELEPHONES & CABLES Ltd 30 June 1970 31500/70 Heading B5A [Also in Division H1A] A plastics insulated conductor is made by extruding plastics insulation 22 over a conductor 21 with an extruder having a tube through which the conductor passes. A pulsating air supply is applied to the input side of the tube to produce air bubbles 23 between the conductor and insulation at intervals along the conductor.