| 摘要 |
PURPOSE:To prevent lowering of light transmission efficiency by splitting a protective tube for optical fiber employed to remote control a boom from working table into plural number then providing tube metal at the end and engaging dismountably with a coupling metal provided on the boom. CONSTITUTION:Optical fiber cable (f) is extended between an electro-optical converter 10 provided on the working table and another electro-optical converter 11 provided on slew table. A pipe 13 for protecting the optical fiber cable (f) is arranged and splitted into three pipes 13a-13c. Pipe metals 14 are mounted at the end section of said pipes 13a-13c. While coupling metals 15 having male screw engagable with said pipe metal 14 are secured to the tips of head boom and base boom in corresponding to the length of pipes 13a-13c. After inserting the optical fiber cable (f) into each pipe 13a-13c, pipe metal 14 and coupling metal 15, pipe metal 14 is screwed over the coupling metal 15 to extend the optical fiber cable (f). |
