JPH0684408U - Optical fiber unit - Google Patents

Abstract

(57) [Summary] [Object] To prevent the side wall of the optical fiber unit base body from falling, and to prevent an increase in transmission loss of the optical fiber core wire housed in the groove of the optical fiber unit base body. [Structure] The optical fiber unit 10 comprises a plurality of optical fiber unit bases 14 gathered around a central member and twisted together. The side walls 14a of the adjacent optical fiber unit bases 14 are connected by the adhesive 18 applied to the gap S between the two side walls 14a.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an improvement of an optical fiber unit for constructing an optical fiber cable used for optical communication or the like.

[0002]

[Prior art]

 Generally, there are several types of optical fiber cables, but as shown in FIG. 6, a central member 12 such as a tension member, an optical fiber unit 10 arranged around the central member 12, and an optical fiber unit 10 An optical fiber cable 40 is known that includes a winding 34 and a protective sheath 36 provided on the outside of the unit 10. As shown in FIG. 7, the optical fiber unit 10 comprises a plurality of optical fiber unit bases 14 gathered around the outer periphery of the central member 12 and twisted together. Each optical fiber unit base 14 has a substantially U-shaped cross section. And has a shape of, for example, a support body 15 in which laminated optical fiber ribbons 16 are housed.

[0003]

[Problems to be solved by the device]

 However, in this optical fiber unit of the prior art, when the optical fiber cable is bent or lateral pressure is applied, the side wall of each optical fiber unit base body 14 constituting the optical fiber unit 10 falls inward or outward and the groove portion thereof falls. There is a drawback that lateral pressure is applied to the optical fiber core wire 16 housed in the optical fiber core, and the transmission loss of the optical fiber core wire forming the optical fiber core wire 16 increases.

The object of the present invention is to avoid the above-mentioned drawbacks, and to prevent the side wall of the optical fiber unit base body from falling down even if the optical fiber cable is bent or subjected to lateral pressure, and the optical fiber core housed in the groove portion is collapsed. An object of the present invention is to provide an optical fiber unit capable of preventing an increase in transmission loss of an optical fiber element wire that constitutes a line.

[0005]

Means for Solving the Problem As a means for solving the above problems, the present invention provides an optical fiber unit comprising a plurality of optical fiber unit bases gathered around the outer periphery of a central member and twisted together. The present invention provides an optical fiber unit characterized in that the side walls of adjacent optical fiber unit bases are connected to each other.

[0006]

[Action]

 In this way, when the side walls of adjacent optical fiber unit bases are connected to each other to form an optical fiber unit, the side walls of each optical fiber unit base support each other, and bending and lateral pressure are applied to the optical fiber cable. However, since it does not easily fall down, it does not affect the optical fiber strands that make up the optical fiber tape core wire that is housed in the groove, increasing the transmission loss of the optical fiber strands. Can be prevented.

[0007]

【Example】

 An embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 shows an optical fiber unit 10 of the present invention. The optical fiber unit 10 is a plurality of twisted fibers gathered around an outer periphery of a central member 12. It is composed of an optical fiber unit base 14. Incidentally, an intervening member or a tension member is used as the central member 12. Further, if necessary, a push-winding (not shown) is provided on the outside of the optical fiber unit 10 of the present invention, and a protective sheath is further coated on the push-winding to form an optical fiber cable.

As shown in FIG. 1, each optical fiber unit base 14 has a groove 14 A and an opening 14 B, and a support 15 having a substantially U-shaped cross section. The respective optical fiber unit bases 14 are gathered around the outer periphery of the central member 12 with their openings 14B facing outward, and are twisted together.

As shown in FIG. 1, a plurality of optical fiber ribbons 16 are stacked and housed in the groove 14 A of the optical fiber unit base 14. As shown in FIG. 2, the optical fiber ribbon 16 is formed by arranging a plurality of optical fiber strands 30 in parallel and covering them collectively with a sheath 32. In the illustrated embodiment, the plurality of optical fiber ribbons 16 thus laminated are housed in the groove 14A of the optical fiber unit base 14, but a single optical fiber core may be housed.

The optical fiber unit 10 is configured by connecting the side walls 14 a of the adjacent optical fiber unit bases 14 to each other. Specifically, as shown in FIG. 1, an adhesive 18 is applied to the gap S (see FIG. 3) between the side walls 14 of the adjacent optical fiber unit bases 14 in the longitudinal direction of the optical fiber unit bases 14. As a result, adjacent optical fiber unit bases 14 are connected to each other. As a result, the side walls 14a of the respective optical fiber unit bases 14 mutually support each other, and the optical fiber unit bases 14 will not fall down even if bending or lateral pressure is applied to the optical fiber cable.

The optical fiber unit base body 14 may be connected by filling the gap S between the side walls 14a of the optical fiber unit 14 with the adhesive 20 as shown in FIG. In this case, as the adhesive 20, for example, silicon putty can be used.

In addition, in the embodiment using the adhesive or pressure-sensitive adhesive shown in FIGS. 1 and 3, as shown in FIG. 4, the length of the optical fiber unit base body 14 is extended in the opening 14 B of each optical fiber unit base body 14. It is desirable to cover the lid 24 in all directions. As a result, it is possible to prevent the optical fiber tape core wires 16 that are stacked and housed in the groove portion 14A of each optical fiber unit substrate 14 from protruding. As shown in FIG. 5, the lid 24 has a convex cross section, and is covered on the optical fiber unit base 14 so that the convex portion engages with the opening 14B.

In the embodiment in which the groove 24A of the optical fiber unit base 14 shown in FIG. 4 is covered with the lid 24, as shown in FIG. 5, the monitoring provided on the lid 24 at regular intervals. The holes 26 may be formed. By providing the monitoring hole 26, it is possible to confirm and monitor the presence or absence of the optical fiber tape core wire 16 stored in the groove portion 14A of the optical fiber unit base 14 and the storage state.

[0014]

[Effect of device]

 According to the present invention, as described above, since the side walls of the adjacent optical fiber unit bases are connected to each other to form the optical fiber unit, the side walls of the respective optical fiber unit bases mutually support each other. Even if bending or lateral pressure is applied to the optical fiber cable, it will not fall down, so it will not affect the optical fiber strands that compose the optical fiber tape core wire stored in the groove, and There is a real benefit that can prevent the transmission loss from increasing.

[Brief description of drawings]

1 is a cross-sectional view of an optical fiber unit of the present invention.

FIG. 2 is a cross-sectional view of an optical fiber ribbon which is housed in the optical fiber unit of the present invention.

FIG. 3 is a cross-sectional view of another embodiment of the optical fiber unit of the present invention.

FIG. 4 is a cross-sectional view of another embodiment of the optical fiber unit of the present invention.

5 (A) is a top view of a lid used in the embodiment shown in FIG. 4, and FIG. 5 (B) is a sectional view taken along line AA of FIG. 5 (A).

FIG. 6 is a cross-sectional view of a general optical fiber cable.

FIG. 7 is a cross-sectional view of a conventional optical fiber unit.

[Explanation of symbols]

 10 Optical Fiber Unit 12 Center Member 14 Optical Fiber Unit Base 14A Groove 14B Opening 14a Side Wall 16 Optical Fiber Tape Core Wire 18 Adhesive 20 Adhesive 24 Lid 26 Monitoring Hole 30 Optical Fiber Wire 32 Sheath 34 Push-up 36 Protective Sheath 40 Fiber optic cable

Front page continuation (72) Tsutomu Akiyama Tsutomu Akiyama 2-6-1, Marunouchi, Chiyoda-ku, Tokyo Furukawa Electric Co., Ltd. (72) Shigeru Tomita 1-6, Uchiyuki-cho, Chiyoda-ku, Tokyo Nihon Telegraph Phone Co., Ltd.

Claims (1)

[Scope of utility model registration request] 1. An optical fiber unit comprising a plurality of optical fiber unit bases gathered around the outer periphery of a central member and twisted together, wherein the side walls of adjacent optical fiber unit bases are connected to each other. .