| 摘要 |
PURPOSE:To obtain a metallic tube which is thoroughly hard over the entire part by delivering a hard metallic tape, forming transversely and successively the tape into a circular shape and welding the butt ends thereof then reducing once the tube with a roller die or die by tandem rolling. CONSTITUTION:While an optical fiber 1 is delivered from a reel 2, a hard metallic tape 3 such as hard Al delivered from a reel 4 is fed through a slitter 5 to a forming unit 6 and while the fiber 1 is housed into the tape 3 formed successively to a semi-circular shape, the tape 3 is rounded to a circular tubular shape. The butt parts of the tape 3 are welded by a torch 7. The metallic tube which cointains the optical fiber and is subjected to welding is passed through a roller die or die 8 and is once reduced to a prescribed size, by which the weld zone is hardened again. The metallic tube which is relatively thin-walled and small-sized and is thoroughly hard over the entire part is thus obtd. |
