JPS6477805A - Optical fiber composite aerial terrestirial wire, its manufacture and tape - Google Patents

Abstract

PURPOSE:To provide optical fibers with sufficient surplus length and enable shrinking of the outside dia. of an OP unit by winding or laying longitudinally a tape which forms a foaming layer partially at the periphery of a bundle of optical fibers, and foaming the foaming layer when it is covered with an aluminum pipe. CONSTITUTION:Foaming agents 3a, 3a are pinched partially between two polymid tapes 2, 2. Optical fibers 1a, 1a are twisted or bundled into a bundle of optical fibers 1, and at its periphery the tapes 2 having foaming agent 3a are wound or laid longitudinally. This is heated to allow the agent to foam, and a foam layer 3 is provided. The tapes themselves deform into corrugated form, and accordingly the inside bundle of optical fibers 1 are deformed into corrugated form, to equip the fibers 1a, 1a with a surplus length on the basis of the corrugated form. An aluminum pipe 4 is laid over this surplus length to constitute an OP unit 10.