OPTICAL FIBER CABLE AND ITS MANUFACTURE METHOD

摘要

PROBLEM TO BE SOLVED: To provide an optical fiber cable capable of effectively restraining a loose tube unit used therein by means of a member forming a pressure resistant layer. SOLUTION: The pressure resistant layer is formed by vertically adding a plurality of metal split pieces 2a or the pressure resistant layer is made by forming a thin pressure resistant plate 2d tubularly. A rugged shape 2c is formed in the direction nearly vertical to the axial direction (arrow K) on the inner peripheral surface of the split piece 2a or the pressure resistant plate 2d and the protruded part 2f of the rugged shape 2c formed on the pressure resistant layer becomes the minimum diameter Di of the central hole of the pressure resistant layer. The loose tube unit 1 is manufactured by inserting a plurality of coated optical fibers 1a and filling gelatinous filler 1c into the loose tube 1d made of resin such as PBT and PP. The outer diameter of the loose tube is made (d). The minimum diameter Di is made smaller than (d) and the protruded part 2f of the rugged shape on the inner peripheral surface of the pressure resistant layer bites the loose tube 1d and restrains the loose tube unit 1 so as not to be moved in the axial direction. COPYRIGHT: (C)2004,JPO&NCIPI