Nippon Telegraph and Telephone Corporation

Fujikura Limited

Yuta Maruo

Hiroaki Tanioka

Shigekatsu Tetsutani

Yusuke Yamada

Hisashi Izumita

Akira Sakurai

Ken Osato

Masatoshi Ohno

Yohei Endo

Akira Namazue

Kouji Tomikawa

An object of the present disclosure is to provide a method of laying an optical cable that is capable of laying and removing the optical cable in a stable place without civil engineering works. To achieve the above-mentioned object, a method of laying an optical cable according to the present disclosure includes laying the optical cable and two laying strips on a road surface or a wall surface so that the optical cable is sandwiched between side surfaces of the two laying strips.

Optical cable laying method

A method of laying an optical cable according to the present disclosure includes: installing a laying strip, in which the optical cable is to be embedded, on a road surface or a wall surface; forming a cut line, for embedding the optical cable, on the installed laying strip; and embedding the optical cable in the formed cut line.

The present disclosure intends to facilitate tearing a metal sheath even in a case where the metal sheath is incorporated in an optical fiber cable. The optical fiber cable of the present disclosure includes a cable core arranged at a central portion and accommodating a plurality of optical fibers gathered together, an inner layer sheath arranged on an outer circumference of the cable core and sheathing the cable core, a metal sheath arranged on an outer circumference of the inner layer sheath and wound around the inner layer sheath, an outer layer sheath arranged on an outer circumference of the metal sheath and sheathing the metal sheath, and at least one outer sheath tearing string arranged in a longitudinal direction inside the metal sheath.

Optical fiber cable

An optical cable includes: twisted optical fiber units each including a fiber group formed by optical fibers. At least one of the optical fiber units includes a filling that wraps an outer circumference of the fiber group.

Optical cable and optical cable manufacturing method

An object is to provide a closure with a structure having a drainage function to eliminate water immersion into a coated optical fiber against temporary flooding and to prevent water from continuously contacting the coated optical fiber. Another object is to provide a closure with improved workability for opening and closing. A closure according to the present invention protects a connection part that connects a coated optical fiber enclosed in a optical fiber cable with a coated optical fiber enclosed in a optical fiber cable. The closure includes a coated optical fiber housing that divides an interior of the closure into a first space that is on a side of a road and has a main body cable insertion hole for inserting the optical fiber cables from an exterior and a second space that is on an opposite side of the road and includes the connection part. The coated optical fiber housing has a frustum shape with two bases each open and a base with a smaller area of the two bases protruding toward the side of the road. The base with the smaller area of the two bases is a cable insertion hole for inserting the optical fiber cable from the first space into the second space and is not in contact with a bottom surface of the first space on the side of the road.

Closure with partition to facilitate draining flood water away from optical fiber connection

An optical fiber cable includes: a cable body having a core and an inner sheath that accommodates the core; a reinforcing sheet that surrounds the cable body; an outer sheath that accommodates the cable body and the reinforcing sheet; and an outer ripcord that is embedded in the inner sheath. The inner sheath includes a projection that projects outwardly in a radial direction of the optical fiber cable. At least part of the outer ripcord is disposed inside the projection.

Growing community of inventors

Tsukuba, Japan

Yuta Maruo