OPTICAL FIBER CABLE FOR PRESS FEEDING

摘要

PURPOSE:To provide the optical fiber unit having the structure suitable for pneumatically feeding into a spiral tube line. CONSTITUTION:Total 7 pieces of cords consisting of six pieces of optical fibers 1 and one piece of tear cord are twisted. An inside layer coating 3 and an outside layer coating 4 are clad thereon, by which the optical fiber unit is constituted. The twisting direction of the optical fibers is reversed from the twisting direction of the tube line into which this unit is to be inserted. The pitch of the twists is set smaller than the pitch of the twists of the tube line. The twists are relieved and the bending rigidity is lowered, by which the insertion characteristic is improved when this unit is inserted into the spiral tube line.