| 摘要 |
PURPOSE:To prevent breakage of an optical fiber owing to its tension by containing the optical fiber provided with protecting layers which are set while the layers are held bent to spiral or waveform shapes into a pipe. CONSTITUTION:An optical transmission wire 3 is contained freely stretchably in a pipe 2 consisting of metal or plastics. Protecting layers 5 are made into the laminar structure wherein a primary coating layer 5a consisting of silicone rubber, etc., a cushion layer 5b consisting of silicone rubber, etc. having better elasticity than the layer 5a, and a secondary coating layer 5c consisting of nylon, etc. are provided successively on the outside circumference of an optical fiber 4. A shape holding layer 6 consists of a fiber reinforced thermosetting resin wherein fibers 6a consisting of glass fibers or polyamide fibers are coated and impregnated with a thermosetting resin 6b consisting of an epoxy resin or polyester resin, and is set while the layer is held bent spirally, whereby the shape thereof is maintained. |
