JPH089689Y2 - Fiber optic cable tow end - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a pulling end of a square tube type optical fiber cable described below.

[Prior Art] A square tube type optical fiber cable has been proposed as an optical fiber cable capable of densely collecting a large number of optical fibers (for example, thousands of cores).

 FIG. 5 shows an example thereof (two-layer structure).

Reference numeral 10 denotes a square tube type optical fiber unit in which a tape core wire 20 is housed in a square tube 12 described below.

The square tube 12 is made of a channel-shaped plastic (for example, polyethylene) elongated body having a U-shaped cross section, and has a square groove 14. It also has the flexibility to enable twisted gathering.

As an example of the size, the width is 5 mm and the height is 4 mm.

The table core wire 20 includes, for example, about 10 optical fibers 22.
Are arranged in a horizontal row and a common coating 24 is applied.

For example, about ten tape cores 20 are stacked and stored in the groove 14. Therefore, one optical fiber unit
10 becomes about 100 hearts.

The optical fiber unit 10 above is attached to the tension member 30.
Around, the layers are twisted and assembled. In addition, 301 is steel stranded wire of tension member, 302 is PE coated on it.
Etc. are plastics.

At this time, the opening side 16 of the groove 14 of the square tube 12 is on the outside and the bottom surface 18 is on the inside.

After the first layer 101 is formed as described above, the press winding 32 is applied onto the first layer 101, and the second layer 102 of the optical fiber unit 10 is further formed thereon in the same manner as above.

At that time, the collective twist direction is opposite to the first layer 101.

That is, when the twisting direction of the first layer 101 is rightward, for example, the twisting direction of the second layer 102 is leftward (if there is a third layer, the twisting direction is rightward). .

A presser winding 34 is applied on the second layer 102, and a sheath 36 is placed on the presser winding 34.
To provide.

[Problems to be solved by the invention] It is difficult to pull the cable having the above structure.

In the case of the slot type optical cable, since it is possible to apply a force to a portion other than the groove of the slot, it is possible to cover the pulling end with a cap, crimp it from the outside, and pull it together with the tension member.

However, in the case of this square tube type optical cable, since the square tube is crushed and the force does not act effectively, it is impossible to cover the cap and crimp it from the outside as described above.

Further, if only the tension member 30 is pulled, only the tension member may be pulled out.

[Means for Solving the Problems] (1) At the end of the optical fiber cable, the respective square tubes are fixed to each other at the intersections of the optical fiber units of the upper and lower layers, and (2) the fixed portion is fixed. , Mechanically connected to the tension member.

[Operation] When the tension member is pulled, the force uniformly acts on all the optical fiber units mechanically connected to the tension member.

When a tensile force acts on the fixed parts of the upper and lower layers, the twisting force of the left-twisted unit and the twisting force of the right-twisted unit are canceled out, and the cable twists. Does not cause

[Example] Fig. 1 schematically shows a state in which the square tubes of the upper and lower optical fiber units are fixed. The illustration of the tape core wire 20 is omitted because the drawing becomes complicated. The distance between the optical fiber units 10 is shown larger than it actually is.

A wire 40 is used as an example of a means for fixing the square tubes 12 that cross each other in the vertical direction. With this wire 40, the crossing position is tied and fixed to each other.

A single wire 40 may be used to tie a plurality of intersecting portions one after another, or to each of the intersecting portions separately.

In the case of the above two-layer structure, the second layer has a larger number of units. Therefore, one unit 1 of the first layer 101
The two units 10 of the second layer 102 may be fixed to 0 (for example, the rightmost one in FIG. 1).

When tying with the wire 40, as shown in FIG. 2, if the recessed portion 13 is formed in the upper square tube 12, the tying can be performed more easily and more reliably.

After the above processing is completed, as shown in FIG. 3, the plastic 302 at the end of the tension member 30 is removed and the steel stranded wire 3
01 is exposed, sleeve 42 is fitted on it, and cap 44 is covered. As the material of the cap 44, a metal having a large tensile strength is used.

 Then, the epoxy resin 46 is filled in the cap 44.

The epoxy resin 46 strongly adheres to the wire 40, the cap 44, and the tension member 30 that bind the square tube 12. As a result, the wire 40 and the tension member 30 are mechanically connected via the epoxy resin 46 and the cap 44.

Fit a metal fitting 50 with a pooling eye 48 on the end of the tension member 30 and crimp it to fix it.

 In this way, the towed end is completed.

[Another Embodiment] As shown in FIG. 4, (1) a wire in which each intersection of the optical fiber unit 10 is bound.
40 is further wound around the tension member 30 and tied. In this way, the connection with the tension member 30 of the optical fiber unit 10 becomes more reliable.

(2) Apart from binding the intersecting portion of the optical fiber unit 10, the entire optical fiber unit 10 of the first layer 101 is bound together with a wire 52 or the like from above. Further, the entire optical fiber unit 10 of the second layer 102 is collectively bound with a wire 54 or the like from above.

Further, those wires 52, 54 may be tied to the tension member 30.

[Effect of the Invention] At the end of the optical fiber cable, the respective square tubes are fixed to each other at the intersections of the optical fiber units of the upper and lower layers, and the fixed portion is mechanically connected to the tension member. When the tension member is pulled, the force is uniformly applied to all the optical fiber units, and the cable can be pulled without being caulked from the outside.

Further, even if a tensile force acts on the optical fiber unit, the cable does not twist.

[Brief description of drawings]

1 to 4 relate to an embodiment of the present invention. FIG. 1 is a schematic explanatory view of a state in which an intersecting portion of an optical fiber unit 10 is fixed, and FIG. 2 shows a recess 13 formed in the fixing portion. FIG. 3 is a schematic explanatory view of a section of the pulling end, FIG. 4 is an explanatory view of another embodiment, and FIG. 5 is an explanatory view of a square tube type optical fiber cable.
It is common to the present invention and the prior art. 10: Optical fiber unit 12: Square tube, 13: Recessed portion 14: Groove, 16: Opening side 18: Bottom surface, 20: Tape core wire 22: Optical fiber, 24: Common coating 30: Center tension member 32, 34: Presser winding , 36: sheath 40, 52, 54: wire, 42: sleeve 44: cap, 46: epoxy resin 48: pooling eye, 50: metal fitting 101: first layer, 102: second layer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Yoshio Kikuchi, 1440 Rokuzaki, Sakura-shi, Chiba Prefecture, Sakura Factory, Fujikura Cable Co., Ltd. (72) Hideo Suzuki, 1440, Rokuzaki, Sakura City, Chiba Prefecture, Fujikura Cable, Ltd. 72) Creator Shigeru Tomita 1-1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corporation

Claims (1)

[Scope of utility model registration request] 1. An optical fiber unit having a structure in which an optical fiber tape core wire is housed in a groove of a rectangular tube made of a channel-shaped long plastic body, and a plurality of layers are twisted and assembled around a central tension member. At the end of the optical fiber cable, the collective twisting direction of each layer is opposite to the collective twisting direction of the layer directly above or below the layer. A pulling end of a fiber optic cable in which the respective corner tubes are fixed to each other at the intersections of, and the fixing portions are mechanically connected to the tension members.