| 摘要 |
PURPOSE:To locally suppress running water when water infiltrates an optical cable unit and to improve the water stopping power of the unit by consisting the retaining winding of the optical cable unit of multi-layered windings and specifying the hardness and winding tension of the tapes for the inside layers to the values lower than the values of the outside layers. CONSTITUTION:Plural pieces of optical tape cores 2 are housed into the plural grooves on the outer peripheral face of a bar-shaped spacer 1 and the retaining winding 5 is formed on the outer periphery thereof. The retaining winding 5 is formed by laminating the tapes consisting of a water absorptive and swellable material to >=2 layers. The hardness and winding tension of the water absorptive tapes I3 of the inside layers in contact with the spacer 1 are specified to the values of the water absorptive tapes II4 for the outside layers or below. As a result, the inside layer tapes I3 in contact with the spacer 1 are soft and, therefore, the spacing between the optical tape cores 2 and the tapes I3 is decreased so that the water infiltrating the cable unit is easily stopped. The running water is thereby suppressed and the water stopping power is improved. |
