APPARATUS AND METHOD USED IN THE ASSEMBLY OF FIBRE OPTIC CABLES

APPARATUS AND METHOD USED IN THE ASSEMBLY OF FIBRE OPTIC CABLES An optical cable is assembled by laying up optical fibres around the surface of a central strength filament. To minimize longitudinal tension in the fibres, air is directed along the surface of the cable in a feed direction. A blow-pipe type device has a pair of concentric tubes along the central longitudinal axis of which cable is drawn. The tubes are sealed together at the upstream end, the outer tube extending beyond the inner tube at the downstream end. Compressed air injected between the tubes is directed along the cable surface as it escapes from the downstream end. The air jet both frictionally urges fibres in the feed direction and creates a partial vacuum over the fibres to locally reduce contact pressure between the fibres and the central strength filament. - i