| 摘要 |
PURPOSE:To prevent the shrinkage of a water-proof intimate mixture at a low temp. and the generation of microbending by contg. at least one wire rod without twisting the same with optical fiber strands into a tube. CONSTITUTION:The optical fibers 2 and the wire rods 3 inserted straightly without being twisted together with the fibers 2 are contained into the tube 1 made of a thermoplastic resin and the water-proof intimate mixture 4 is packed into the remaining space. Hard copper wires and FRP reinforced with long fibers, etc. are used for the rods 3. The rods 3 consisting of the material having the moduls of elasticity in bending larger than the moduls of elasticity in bending of the optical fiber strands are contained in the tube 1 without twisting the same with the fibers in the above-mentioned manner and therefore the longitudinal shrinkage of the mixture 4 is absorbed and relieved by the rods 3 at the low temp. and the generation of the side pressure owing to the microbending arising from the shrinkage is prevented.
|
