JP3105125B2 - Optical fiber cable exit method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for tapping an optical cable having a small diameter and a small number of cores, which is used mainly for indoor wiring in an optical communication line.

[0002]

2. Description of the Related Art FIG . 2 shows an example of an outdoor optical fiber cable 10 (see Japanese Patent Publication No. 4-70606). The two optical fiber cores 12 are arranged in a line in contact with each other in the left-right direction (the left, right, up, and down are determined as indicated by arrows 13). The tension members 14 are disposed on the left and right sides of the optical fiber core 12 at positions away from the optical fiber core 12. A common plastic coating layer 16 is provided for the optical fiber core 12 and the tension member 14. A groove 18 for tearing is provided on the surface of the coating layer 16 in the vertical direction.

[0003] In the case of indoor wiring, for example, as shown in FIG . When the optical fiber core 12 is exposed, the following is performed.
That is, as shown in FIG.
The covering layer 16 is cut right and left. Then, the optical fiber cable 10 is split into two at the optical fiber core 12.
A part of the optical fiber core 12 is exposed on the separation surface.
Therefore, it can be taken out of the coating layer 16 relatively easily.

[0004]

(1) When the optical fiber core 12 is a tape core as shown in FIG. 5 , even if the coating layer 16 is torn to the right and left as shown in FIG. It is difficult to remove it from the coating layer 16 and there is a fear of scratching. (2) When tearing right and left as shown in FIG. 4 , the tension member 14 is pulled and curled, and the optical fiber core wire 12 may be damaged.

[0005]

[Means for Solving the Problems] In order to solve the above-mentioned problems
, As in FIG. 1 (a), the structure of the optical fiber cable 30 as follows. The plurality of optical fibers 32 are
Arrange them in one row in the horizontal direction. The tension members 34 are arranged on the left and right sides of the optical fiber core 32 at positions away from the optical fiber core. The optical fiber core 32 and the tension member 34 are provided with a common plastic coating layer 36 having no slit for cleavage on the surface in the vertical direction.

An optical fiber cable having such a structure is
The bull 30 is tapped by the following method. Coating layers 360 on both outer sides of tension member 34 as viewed from the left and right directions
(FIGS. 1A and 1B). The tension member 34 is taken out of the coating layer 36 (c). A cut 364 leading from the hole 362 after the tension member 34 is taken out to the optical fiber core 32 is inserted into the coating layer (c). Thereafter, the coating layer 36 is separated into an upper half 366 and a lower half 368 (d).

First, the optical fiber cable 30 will be described.
I will tell. In the case of FIG. 1, two optical fiber ribbons 32 are used as the optical fiber ribbons 32, and they are arranged side by side and in contact with each other. The coating material of the optical fiber core 32 is preferably a polyamide resin. Optical fiber core 32
Is not limited to the above, and the following mode is also conceivable. Use a single core instead of tape. Slightly separate without touching each other. Not only Article 2, but Article 3 or more. The optical fibers 32 are not overlapped in the vertical direction, but are arranged in a row. If the layers are vertically stacked, the impact and lateral pressure characteristics deteriorate, so that problems such as breakage of the tape and an increase in transmission loss tend to occur. As the tension member 34, for example, a steel wire or the like is used.

The material of the covering layer 36 is polyethylene or the like. The coating layer 36 is made of polyethylene and the optical fiber core 32
When a polyamide resin (nylon) is used for coating, the adhesiveness thereof is not good.
When the fiber 6 is torn up and down, the optical fiber core 32 is easily taken out from the coating layer 36. The cross section of the coating layer 36 is, for example, a flat barrel shape obtained by cutting the upper and lower bow portions 38 from a circle, and has a shape in which a bow-shaped concave portion 40 is formed at the center of both upper and lower surfaces. The concave portion 40 is provided for improving impact characteristics and lateral pressure characteristics. The vertical thickness a of the optical fiber core 32 is made larger than the distance b between the optical fiber core 32 and the tension member 34. The reason for this is that when the film is torn in the vertical direction, the portion a is continuously torn at the portion b without tearing.

When this optical fiber cable 10 is used as it is or after being sheathed and wound around the support wire 24 as shown in FIG. 6 , it can be used for outdoor wiring.

The exit of such an optical fiber cable 30
This is performed as follows. About 10 cm of the end of the cable to be taken out, the outer coating layer 360 is cut off from the chain line 42 in FIG. One method is to make a mark on the surface of the coating layer 36 so that the position to be shaved is known. A knife or the like is used to make the cut 364 as shown in FIG.
As shown in (d), in order to separate the coating layer 36 up and down, it is sufficient to hold the coating layer 36 at the cable end and tear it up and down. When the coating layer 36 is separated vertically, the optical fiber core 32 is exposed on the separation surface, so that it can be easily taken out without any damage.

[0011]

[Effects] (1) Coating layer 3 of optical fiber cable 30
Since there is no groove for tearing on the surface in the up-down direction of 6, it becomes strong against impact. If there is a groove for tearing on the surface of the coating layer when the object hits strongly during storage, it may tear from that part.
There is no. (2) When stopped by staples, as described above, there is no groove for tearing on the surface of the coating layer 36, so there is no fear of tearing. (3) Cover layers 360 on both left and right sides of tension member 34
Is removed, the tension member 34 is taken out of the coating layer, and a cut 364 reaching the optical fiber core 32 from the hole 362 after the tension member is taken out is inserted into the coating layer. Just by adding
6 can be separated up and down. (4) Since the coating layer 36 is vertically separated, the optical fiber cores arranged in a line in the left-right direction as described above are exposed on the separation surface of the coating layer. Therefore, even if it is elongated left and right like a tape core wire, it can be easily taken out of the coating without damaging it. The same applies to a case where there are three or more tape cores or a case where the tape cores are separated from each other. (5) When separating the coating layer 36 up and down, only the coating layer 36 is torn and the tension member 34 is not contained therein. The core wire 32 is not damaged.

[Brief description of the drawings]

FIG. 1 is an explanatory view of an embodiment of the present invention, in which (a) shows a cross section, and (b) to (d) show a tapping method in the order of steps.

FIG. 2 is a sectional view showing a conventional optical fiber cable 10;
FIG.

FIG. 3 shows a conventional optical fiber cable 10 which is stapled.
Explanatory drawing of the state which stopped.

FIG. 4 pulls a conventional optical fiber cable 10 left and right.
Explanatory drawing of the torn state .

FIG. 5 is a sectional view showing an example of a conventional optical fiber cable.
FIG.

FIG. 6 is a cross section showing an example of a conventional optical fiber cable.
FIG.

[Explanation of symbols]

10, 30 ... optical fiber cable, 12, 32 ... optical fiber core, 14, 26, 34 ... tension member, 1
6, 36 coating layer, 18 slit groove, 20 staple, 22 structure, 24 support wire, 28 coating 360
... Outer part, 362 ... Hole, 364 ... Cut, 366 ...
Upper half, 368: Lower half, 38: Bow-shaped part, 40: Recess, 42: Chain line

Continuation of the front page (72) Inventor Hiroyuki Sawano 1440 Mutsuzaki, Sakura-shi, Chiba Pref. Fujikura Co., Ltd. Sakura Plant (56) Reference Reference U) Japanese Utility Model 2-69305 (JP, U) Japanese Utility Model 5-45612 (JP, U) Japanese Utility Model 63-1212 (JP, U) Japanese Utility Model 63-33111 (JP, U) (58) Survey Field (Int.Cl. ⁷ , DB name) G02B 6/44 G02B 6/00

Claims (1)

(57) [Claims] An optical fiber is provided on both left and right sides of an optical fiber.
The tension member is located at a position away from the fiber core.
Are integrated by a common plastic coating layer
In the end portion of the optical fiber cable, the surface of the coating layer in the vertical direction in which the optical fiber core wire is disposed is provided with a concave portion having no groove for tearing along the longitudinal direction.
Removing the coating layer outside the tension member in the left-right direction, taking out the tension member outside the coating layer, from the hole after taking out the tension member, cut a line on the optical fiber core wire, A method for tapping an optical fiber cable, comprising the steps of: placing in the coating layer; and separating the coating layer into an upper half and a lower half.