METHOD OF AND APPARATUS FOR MANUFACTURING CORE WIRE FOR OPTICAL FIBERS

摘要

An apparatus for manufacturing a core wire for use in laying optical fibers over a long distance produces a plurality of continuous corrugated deep grooves in a wire that are capable of holding therein the optical fibers longitudinally along the peripheral surface of the wire. An endless raw wire material of circular cross section is formed by the apparatus into a wire of square cross section through plastic processing and thereafter the wire is formed into a core wire of a flower patterned cross section with a plurality of petals having corrugated deep grooves in the periphery thereof continuously longitudinally thereof through a rolling device. In addition, the core wire so constructed is formed into a core wire with spiral corrugated deep grooves formed in the peripheral surface thereof. The rolling means has forming rolls equal in number to the number of ridges of the square wire, and each such roll having two perfect corrugated convex portions formed widthwise on the peripheral surface thereof. All the peripheral surfaces of the forming rolls are directed to a point on the wire travelling path, whereby each ridge of the wire is positioned between the two convex portions of each roll. The torsion processing device advantageously has a freely rotatable rim arranged for taking the core wire travelling path as a tangential line, and the rim is rotatable on the contact point between the core wire travelling path and the rim itself perpendicularly to the surface thereof to permit the core wire to be turned around the peripheral surface thereof.