| 摘要 |
PURPOSE:To prevent local bending from occurring without being affected by the burr nor edge of the cut end surface of a metallic tube even if the end of the metallic tube is bent by composing the optical fiber of a 1st heat-shrinkable tube whose external diameter after heat shrinkage is nearly equal to the external diameter of the metallic tube and a 2nd heat-shrinkable tube which is provided while riding over the 1st heat- shrinkable tube and the metallic tube. CONSTITUTION:The optical fiber 1 is run through the projecting metallic pipe 2 of the optical fiber 1 on the end part side. The optical fiber is composed of the 1st heat- shrinkable tube 6 which abuts on the end part of the metallic tube 2 and has the external diameter after the heat shrinkage nearly equal to the external diameter of the metallic tube 2 and the 2nd heat-shrinkable tube 6a which is provided while riding over the 1st heat-shrinkable tube 5 and the metallic tube 2. Therefore, even if the metallic tube is bent at its end, the gap between the optical fiber 1 and metallic tube 2 is held, the bending stress is dispersed in a longitudinal direction and the optical fiber neither touches the burr and edge of the cut surface of the metallic tube 2 not curves locally. Consequently, even is the metallic tube is bent at its end, the metallic tube is affected by neither the burr nor the edge of the cut end surface of the metallic tube and the local curvature is precluded. |
