| 摘要 |
PURPOSE:To improve watertightness and side pressure resistance, and to decrease an external diameter, by packing jerry in the layer of an optical fiber core, covering its external circumference lengthwise with a metallic plastic tape through a jerry buffer layer, and laminating a hard thermoplastic sheath around the external circumference of the tape. CONSTITUTION:Optical fiber cores 2 are stranded into one layer around the external circumference of a tension wire body 1 such as a copper-plate steel wire, and a plastic wire reinforced by glass fiber, and jerry 9 is packed among the core wires 2. The external circumference is covered with polypropylene yarn, a pressure winding layer of nylon yarn, etc., is provided around the external circumference of the yarn, and jerry is packed in it to form jerry buffer layers 3 and 4. The external circumference of the layers is covered lengthwise with a metal-plastic laminate tape 5, whose external circumference is covered with a hard thermoplastic sheath 6 of polyethylene, etc. Thus, watertightness and side pressure resistance are improved, and the external diameter is reduced. |
