| 摘要 |
PURPOSE:To eliminate the breakage of a tail cable near a free gimbals coupling by running optical fiber cores in an optical fiber unit individual through small- diameter metallic pipes, and stranding them. CONSTITUTION:Small-diameter metallic pipes 17 which function for optical fiber core protection and feeding and a small-diameter metallic pipe 18 at the center position of stranding form a feeder line, and an insulator 19 made of polyethylene for insulating the small-diameter pipes is provided. Namely, the tail cable is constituted by stranding the small-diameter metallic pipes 17 as many as all optical fiber cores 11 in the optical fiber unit 10 which run through the pipes around the small-diameter metallic pipe 18 at the center position of the stranding at nearly the same pitch as the stranding pitch of the optical fiber cores, coating the stranded small-diameter metallic pipes 18 with the insulator 19 of polyethylene, etc., and forming this in a coil shape. |
