JPH04182609A - Cord forming and branching part for coated multiple optical fiber tape - Google Patents

Abstract

PURPOSE:To evade twisting or the like to be generated in a coated optical fiber and to prevent the generation of loss in optical transmission by cord- forming and branching plural coated optical fiber tapes incorporated and arrayed in a multiple optical fiber cable under a similar arraying state. CONSTITUTION:Plural distribution grooves 21 are formed in an axial direction on the outside circumference of a core 2 and the inserting hole of the tension member 13 of the optical fiber cable 1 is formed at the center thereof. Besides, the core 2 is shaped similar to a separator 12. Then, the coated fiber tapes 14 fed from a distribution groove 11 are inserted in a protection tube 22, arrayed and housed in the groove 21 under the similar arraying state to the inside of the cable 1. Besides, they are formed to the cords and branched 10. At such a time, the core 12 and the tube 22, the tube 22 and a nylon tube 5 are respec tively fixed by adhesive and the core 2 is mechanically fixed to a member 13 by a fixing jig 4. Then, an outside cap 3 is mounted and engaged on the outside circumference.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention encodes and branches a plurality of optical fiber tapes built into a multi-core optical fiber cable for each tape fiber, and splits them into, for example, This relates to a branch section used when connecting to transmission equipment, etc.

(Prior Art) In a multi-core optical fiber cable in which a plurality of optical fiber tape cores are internally arranged, coding branching of a so-called non-gas cable, which does not contain gas inside, is a new technology to be tackled.

As a conventional similar technology, for example, Japanese Patent Application Laid-Open No. 1383-1983
There is a branch part of a multi-core optical fiber cable as shown in No. 03.

FIG. 3 is an explanatory diagram of a branch part of such a multi-core optical fiber cable, in which (A) is a longitudinal cross-sectional view, and (II) is a cross-sectional view along the line X2 and X2 in FIG. (A).

As shown in the drawings, an optical fiber core distribution medium is rod-shaped and has at least a conical tapered portion, and has a plurality of distribution grooves (1051) and a cut portion (IOEi) that reaches the center formed in the axial direction on its outer circumference. a cylindrical cap (107) attached to the outer periphery of the core (104), and a plurality of protective tubes (+03) fitted into the distribution grooves (104) of the core (104). The multi-core optical fiber cable (100) is equipped with an optical fiber cable (100).
1) is the protective tube (103) into which the core wire is inserted;
The tension member (102) is stored in the distribution groove (105) of the core (104) through the
is supported through the cut portion (+ollf) of the core (1G4).

(Problems to be Solved) However, the branch portion of the multi-core optical fiber cable as described above has the following problems.

■The structure is such that only one fiber can be stored in the distribution groove of the core, but as the number of optical fibers increases, the outer diameter of the core not only increases in proportion to the number of fibers, but also increases the number of optical fibers that are built into the cable. It is not possible to code and branch the arranged optical fibers without twisting them.

■The tension member is passed through the cut part of the core and supported by its elasticity, but due to the structure of optical fiber cables, the tension member and the outer sheath are not completely integrated. Therefore, mutual movement is unavoidable due to environmental temperature changes, tension during installation, etc. As a result, it is extremely difficult to prevent misalignment between the tension member and the core, or even between the core and the outer cap, using only the elasticity of the core.

■At the same time, the core and outer cap become misaligned,
Fixation of the protective tube to the distribution groove by pressure cannot be guaranteed.

When an optical fiber core wire is coded and branched, bending, pressure, twisting, tension, etc. occur in the core wire, and optical transmission loss becomes unstable.

(Means for Solving the Problems) The present invention provides a coded branching section of a multi-core optical fiber ribbon which solves the above-mentioned problems, and its characteristics are as follows:
Protection by inserting a plurality of optical fiber ribbons arranged internally in a multi-core optical fiber cable into the distribution grooves of the core, which has a cylindrical shape and has a tapered portion at the tip and a plurality of distribution grooves formed in the axial direction of the outer circumference. The tubes are stored and arranged, the core is fixed to the tension member of the optical fiber cable using a fixing jig, and an outer cap is attached to the outer periphery of the core. This is because a plurality of tape core wires are coded and branched in a similar arrangement.

(Example) Fig. 1 is a vertical cross-sectional view of a specific example of the coded branch section of the present invention, Fig. 2 (a) is a cross-sectional view of a multi-core optical fiber cable, and (+11) in the same figure is a longitudinal cross-sectional view of a specific example of the coded branch section of the present invention. Detailed view of part A of the same figure (c)
is a sectional view taken along the line X and -X in FIG.

In the drawing, (1) is a multi-core optical fiber cable, which has a distribution groove (11) in the axial direction on the outer periphery, and a tension member (13) in the center, as shown in its cross-sectional shape in FIG. ) of the separator (+2) with said distribution groove (
11), a plurality of optical fiber tape cores (14) are arranged and housed, and a protective coating layer (15) made of plastic or the like is provided on the outside thereof.

(2) is a cylindrical core with a tapered part at the tip, and on its outer periphery, as shown in Figure 2 (c), a plurality of distribution grooves (21) are formed in the axial direction. has an insertion hole for the tension member (13) of the optical fiber cable (1), and has a similar shape as a whole to the separator (12) of the optical fiber cable (1). And the distribution groove (II) of the separator (12) of the optical fiber cable (1)
The tape core wire (14) taken out from the protective tube (
22), and are arranged and housed in the distribution groove (21) in the same arrangement as in the optical fiber cable (1), and are coded and branched (lO). At this time, the core (2) and the protective tube (22) and the protective tube (22) and the nylon tube (5) are each fixed with an adhesive. The protective tube (22) is formed on the nylon tube (5) as shown in FIG.
The exposed tape core (14) located between 1) is protected by inserting a spacer (6). Further, the core (2) is mechanically fixed by a fixing jig (4) to a tensicon member (+3) inserted through its center.

(3) is an outer cap made of a plastic material etc. attached to the outer periphery of the core (2), and the short diameter end of the outer cap is located on the outer coating layer (+5) of the optical fiber cable (1). and fixed with a heat shrink tube (7). There is an annular projection (31) on the inner peripheral surface of the outer cap (3) located above the core (2), which fits into an annular recess (23) provided on the outer peripheral surface of the core (2). This prevents axial movement.

In addition, the inner surface of the outer cap (3) has a distribution groove (2) for the core (2).
A plurality of axial protrusions (32) are provided to fit into the core (2), and by fitting the protrusions (32) into the distribution grooves (21) of the core (2), the circumferential direction It prevents movement and presses the protective tube (22) housed therein.

(Effects of the Invention) As explained above, according to the multi-core optical fiber/(tape core coded branch) of the present invention, a plurality of tape core wires arranged internally in a multi-core optical fiber cable can be Since the coded branches are arranged in a manner similar to the above, it is possible to reduce the size of the branch part, and prevent an increase in transmission loss without applying excessive force such as twisting to the tape core wire.

In addition, since the Tensicon member, core, outer cap, and cable are mechanically fixed, it is possible to prevent the outer coating layer of the cable and the Tensicon member from shifting due to environmental temperature changes or tension during cable installation. .

Furthermore, since the protective tube is fixed to the core, it will be in a stable state in the future, no unreasonable force will be applied to the optical fiber ribbon, and a branch portion with low optical transmission loss can be obtained.

Therefore, in order to reduce the diameter of optical fiber cables, tape cores are rapidly being introduced, and tape cores are often coded at the connection part with transmission equipment, etc., and the present invention is extremely useful. It is valid.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a specific example of a coding branch according to the present invention. Figure 2 (A) is a cross-sectional view of the multi-core optical fiber cable, Figure 2 (B) is a detailed view of section A in Figure 1, and Figure 2 (C) is a cross-sectional view taken along line Xl-X in Figure 1. be. FIG. 3 is an explanatory diagram of a branch part of a conventional multi-core optical fiber cable, in which (A) is a longitudinal cross-sectional view, and (+2) is a +2-+2 cross-sectional view of FIG. (A). 1... Multi-core optical fiber cable, 11... Distribution groove,
DESCRIPTION OF SYMBOLS 12... Separator, 13... Tensicon member, 14... Optical fiber tape core, IS... Outer coating layer, 2... Core, 21... Distribution groove, 22... Protective tube, 23... Annular recess, 3... Outer cap, 31... Annular projection, 32...
・Axial protrusion, 4...Fixing jig, 5...Nylon tube, 6...
・Spacer, 7...Heat shrink tube. '$31!1 (I) 102 10/

Claims (3)

[Claims] (1) The core has a cylindrical shape with a tapered portion at the tip and a plurality of distribution grooves formed in the axial direction on the outer periphery, and the plurality of optical fiber ribbons arranged inside the multi-core optical fiber cable are inserted into the distribution grooves of the core. A multi-core optical fiber cable is constructed by arranging a plurality of protective tubes inserted through them, fixing the core to the tension member of the optical fiber cable using a fixing jig, and attaching an outer cap to the outer periphery of the core. 1. A coded branching section of a multi-core optical fiber tape coated wire, characterized in that a plurality of tape coated wires arranged in a built-in array are coded and branched in a similar arrangement state. (2) The coded branch portion of a multi-core optical fiber tape according to claim (1), wherein the core and the protective tube and the protective tube and the nylon tube are respectively fixed with an adhesive. (3) The coded branch portion of a multi-core optical fiber tape according to claim (1), characterized in that the core and the outer cap have a structure that prevents them from moving relative to each other in the axial and circumferential directions.