US-12620790-B2 - Reticulated tube, optical fiber protective unit, method for protecting optical fiber, and method for manufacturing reticulated tube

Abstract

A fixing structure includes: an optical fiber group constituted by a plurality of optical fibers; a tubular member through which the optical fiber group is passed; a reticulated tube, one end part of the reticulated tube being disposed on an outer periphery of the tubular member, the optical fiber group being inserted through an extended section of the reticulated tube extending out from the tubular member; and a fixing member that fixes the tubular member which has the reticulated tube disposed on the outer periphery thereof.

Inventors

• Go Taki
• Masayuki Ishioka
• Mizuki ISAJI
• Tomoaki KAJI
• Soichiro Kaneko
• Koji Tomikawa
• Akira NAMAZUE
• Ken Osato

Assignees

• FUJIKURA LTD.

Dates

Publication Date

20260505

Application Date

20240129

Priority Date

20181004

Claims (13)

1. 1 . A fixing structure comprising: an optical fiber group constituted by a plurality of optical fibers; a tubular member through which the optical fiber group is passed; a reticulated tube, one end part of the reticulated tube being disposed on an outer periphery of the tubular member, the reticulated tube being longer than the tubular member, the optical fiber group being disposed inside an extended section of the reticulated tube extending out from the tubular member; and a fixing member that fixes the tubular member which has the reticulated tube disposed on the outer periphery thereof, wherein a plurality of optical fiber groups branch from a single optical cable, one or more of the optical fiber groups branching from the single optical cable are inserted through a respective one of the tubular member and the reticulated tube, and the fixing member comprises: a first fixing part that fixes an end part of the optical cable; and a second fixing part that fixes a plurality of the tubular members.
2. 2 . The fixing structure according to claim 1 , wherein the optical fiber group is an optical fiber group from a single optical cable.
3. 3 . The fixing structure according to claim 1 , wherein the fixing structure is disposed in a manner that the optical fiber groups branching from the optical cable extend downward from the fixing structure.
4. 4 . The fixing structure according to claim 1 , wherein the second fixing part fixes the tubular members by digging into the tubular members.
5. 5 . The fixing structure according to claim 1 , wherein the second fixing part has teeth that dig into the tubular members.
6. 6 . The fixing structure according to claim 5 , wherein the second fixing part has recessed parts into which the respective tubular members are inserted, and the teeth are constituted by the recessed parts.
7. 7 . The fixing structure according to claim 1 , further comprising a housing part configured to house a lead part of the optical cable at which the plurality of optical fiber groups branch from the optical cable.
8. 8 . The fixing structure according to claim 7 , wherein the housing part is configured in a manner that the housing part can be filled with an adhesive.
9. 9 . The fixing structure according to claim 8 , wherein the housing part includes a stopper that prevents leakage of the adhesive.
10. 10 . The fixing structure according to claim 1 , wherein the optical fiber group comprises an optical fiber ribbon.
11. 11 . The fixing structure according to claim 1 , wherein the fixing structure is disposed on a rack.
12. 12 . A method for fixing a group of optical fibers, comprising: inserting an optical fiber group, which is constituted by a plurality of optical fibers, through a tubular member and a reticulated tube which is longer than the tubular member, the optical fiber group branching from a single optical cable, one end part of the reticulated tube being disposed on an outer periphery of the tubular member, the optical fiber group being disposed inside an extended section of the reticulated tube which extends out from the tubular member; preparing a fixing member including a first fixing part that fixes an end part of the optical cable, and a second fixing part that fixes a plurality of the tubular members; fixing the end part of the optical cable to the first fixing part; and fixing, to the second fixing part, the plurality of tubular members each having the reticulated tube disposed on the outer periphery thereof.
13. 13 . A fixing structure comprising: an optical fiber group constituted by a plurality of optical fibers; a tubular member through which the optical fiber group is passed; a reticulated tube, one end part of the reticulated tube being disposed on an outer periphery of the tubular member, the optical fiber group being inserted through an extended section of the reticulated tube extending out from the tubular member; a fixing member that fixes the tubular member which has the reticulated tube disposed on the outer periphery thereof; and a housing part configured to house a lead part of a single optical cable at which a plurality of optical fiber groups branch from the single optical cable, wherein the fixing member comprises: a first fixing part that fixes an end part of the single optical cable; and a second fixing part that fixes a plurality of the tubular members, one or more of the optical fiber groups branching from the single optical cable are inserted through a respective one of the plurality of the tubular members and the reticulated tube, the housing part is configured in a manner that the housing part can be filled with an adhesive, and the housing part includes a stopper that prevents leakage of the adhesive.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This is a continuation application of U.S. patent application Ser. No. 17/982,661, filed on Nov. 8, 2022, which is a continuation of U.S. patent application Ser. No. 17/282,626, filed on Apr. 2, 2021, which is a national stage of International Patent Application No. PCT/JP2019/036612, filed on Sep. 18, 2019, which claims priority from Japanese Patent Application No. 2018-189278, filed on Oct. 4, 2018. The contents of these applications are incorporated herein by reference in their entirety. TECHNICAL FIELD The present invention relates to a reticulated tube, an optical fiber protective unit, a method for protecting an optical fiber, and a method for manufacturing a reticulated tube. BACKGROUND Patent Literatures 1 to 4 describe an optical fiber unit formed by wrapping a bundling member around a bundle of a plurality of optical fibers. Patent Literatures 3 and 4 describe a method for manufacturing an optical fiber unit by wrapping a bundling member around a bundle of a plurality of optical fibers. Further, Patent Literatures 5 to 7 describe various tubes. Patent Literature 5 describes a protective tube that protects an optical fiber by covering an outer periphery of the optical fiber. Patent Literature 6 describes that a plastic line or a metal line is braided and formed into a cylindrical net capable of extension and contraction to protect wiring. Patent Literature 7 describes a net tube having a diameter enlarged when the net tube shrinks, and that the net tube protects an electric wire. CITATION LIST Patent Literature Patent Literature 1: WO 2015/053146Patent Literature 2: JP 2011-169939APatent Literature 3: JP 2013-97320APatent Literature 4: JP 2018-049081APatent Literature 5: JP 2017-215438APatent Literature 6: JPU 63 (1988)-49356APatent Literature 7: JP 2002-10441A The bundling member described in Patent Literatures 1 to 4 is wrapped around an outer periphery of a bundle of a plurality of optical fibers at a manufacturing factory in order to bind the plurality of optical fibers. Thus, the bundling member described in Patent Literatures 1 to 4 does not protect the optical fibers, and is not inserted with the optical fibers therethrough. Further, the bundling member described in Patent Literatures 1 to 4 is not assumed to be attached to an outer periphery of a bundle of optical fibers when the optical fibers are laid at a laying site (it should be noted that it is difficult to attach the bundling member described in Patent Literatures 1 to 4 to an outer periphery of a bundle of optical fibers when the optical fibers are laid at a laying site). Further, in a case of the protective tube described in Patent Literature 5 and a spiral tube described in the prior art in Patent Literature 6, work for inserting optical fibers takes time and effort. In a case of a braided tube (tube constituted by braiding a wire) described in Patent Literatures 6 and 7, the amount of extension and contraction in a longitudinal direction is small, and thus work for inserting optical fibers also takes time and effort in this case. In addition, when optical fibers are inserted through the braided tube having the diameter changed during extension and contraction, a diameter becomes thin when the braided tube is extended in the longitudinal direction. Thus, pressure is applied to the optical fibers inserted through the inside, and a transmission loss of the optical fibers increases. SUMMARY One or more embodiments of the present invention provide a new protective tube that is configured to be inserted with optical fibers through the tube when the optical fibers are laid, has a great amount of extension and contraction in a longitudinal direction, and suppresses a diameter becoming thin during extension. One or more embodiments of the present invention is a reticulated tube comprising openings reticulately formed, and the reticulated tube is configured to be inserted with a plurality of optical fibers through the reticulated tube. Other features of embodiments of the invention are made clear by the following description and the drawings. With one or more embodiments of the present invention, it is possible to protect a plurality of optical fibers by inserting the optical fibers through a reticulated tube when the optical fibers are laid. Since openings are reticulately formed, the amount of extension and contraction in a longitudinal direction is great, and it is possible to suppress a diameter becoming thin during extension. BRIEF DESCRIPTION OF DRAWINGS FIG. 1A is an explanatory diagram of an optical fiber unit 3 according to one or more embodiments. FIG. 1B is an explanatory diagram of the optical fiber unit 3 in a state in which a reticulated tube 10 is folded according to one or more embodiments. FIG. 2A is a developed view for illustrating a shape of the reticulated tube 10 according to one or more embodiments. FIG. 2B is an enlarged perspective view of the reticulated tube 10 illustrated