JPH0336971Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a self-supporting optical fiber cable in which a cable support line and a cable main body are integrally covered with the same protective sheath.

[Conventional technology]

Self-supporting optical fiber cables (SS optical fiber cables) can be made into cables in the same way as so-called round cables without support wires, and can be easily applied overhead, contributing to labor savings in cable installation work. commonly used as.

A conventional SS optical cable, as shown in FIGS. 1 and 2, for example, includes a cable support line 1 made of a twisted wire or the like, and a plurality of optical fiber core wires 2, 2...
The cable main body 3 made up of the cable support wire 1 and the cable main body 3 are kept parallel to each other and are integrally covered with the same protective sheath 4 made of plastic material. It has a configuration in which a connecting portion 5 is formed to connect the two.

In addition, severe bending, vibration, and
A low friction layer or a buffer layer is interposed between the cable body 3 and the protective sheath 4 in order to reduce the local stress acting on the optical fiber core wires 2, 2... due to tension and reduce the rate of breakage. (Japanese Patent Laid-Open No. 1983
-Refer to Publication No. 156944).

By the way, when wiring the SS optical cable configured in this way outdoors, it is installed on a utility pole etc. while applying tension to the cable support wire 1, and the cable main body 3 is held by the connection part 5 of the protective sheath 4. It is strung so that there is no excessive slack as a whole.

When the cables strung in this way are brought indoors and each optical fiber core 2 is individually wired to communication equipment, terminal equipment, etc., the rigid cable support wire 1 obstructs the freedom of wiring. This needs to be removed as it gets in the way.

This cutting operation of the cable support line 1 involves removing the entire protective sheath 4 that integrally covers the cable support line 1 and the cable body 3 together with the cable support line 1 at a portion corresponding to the wiring length of the cable body 3. A common method is to cut the cable in the radial direction, and then pull the cut part strongly in the axial direction of the cable to remove it from the periphery of the cable body 3.

[The problem that the idea aims to solve]

However, if the protective sheath 4 is pulled out while being strongly pulled over the wiring length of the cable body 3, there is a risk of putting an unreasonable load on the optical fiber cores 2, 2, etc. that make up the cable body 3, and damaging them. There is. Also, when the protective sheath 4 is removed, the optical fiber core wires 2, 2 forming the cable body 3 are
...becomes scattered over the entire length of the wiring,
The disadvantage is that the optical fiber cores 2 become intertwined with each other, causing significant trouble in wiring work.

In addition, instead of using the above method, as shown in FIG. 1, the connecting portion 5 of the protective sheath 4 is cut in the direction of arrow F by the wiring length of the cable main body 3, and the cable support line 1 and the cable main body 3 are separated from each other. If a method is adopted in which only the cable support line 1 is cut after separation, the cable body 3 is covered with a protective sheath 4.
remains, so when wiring, optical fiber core wires 2, 2...
... can be avoided from becoming complicated. Moreover, since the protective sheath 4 that covers the cable body 3 only needs to be cut by the length for centering the optical fiber core wires 2, 2..., when removing the protective sheath 4 from around the cable body 3, Optical fiber core wire 2, 2...
There is little worry about damaging it.

However, in this case, the work of cutting the connecting portion 5 of the protective sheath 4 over the length of the wiring of the cable body 3 is extremely troublesome, so it cannot be said to be a practical means.

Therefore, the present invention makes it possible to easily cut out the cable support wires that hinder the freedom of wiring when bringing the cable body of a self-supporting optical fiber cable from outdoors to indoors and wiring it individually without any trouble. The technical problem is to prevent the optical fiber core wires that make up the cable body from falling apart even if the support wire is removed, and by solving this problem, it is easy to install self-supporting optical fiber cables. The purpose is to prevent damage to the optical fiber.

[Means to solve the problem]

In order to achieve this objective, the present invention provides a cable support line made of twisted wire, etc., and a cable body made of a plurality of optical fiber cores, which are kept parallel to each other and covered with the same protective sheath. In a self-supporting optical fiber cable that is integrally coated, a binding layer that loosely inserts and holds the cable body and a protective sheath that covers the binding layer are concentrically coated on the outside of the cable body, and these binding layers are coated concentrically. A gap is formed between the layer and the protective sheath to the extent that the cut portion of the protective sheath, which is cut in the radial direction together with the cable support wire, can smoothly slide along the axial direction of the cable. shall be.

[Effect]

According to the present invention, when the terminal side of a self-supporting optical fiber cable strung outdoors is brought indoors and individually wired, the entire protective sheath is combined with the cable support wire at a portion corresponding to the wiring length. The cable is cut in the radial direction, and the cut part is pulled in the axial direction of the cable to remove it from around the binding layer coated on the outside of the cable body.

At this time, since a gap is formed between the binding layer and the protective sheath to allow the protective sheath to slide smoothly, the work of removing the cut protective sheath can be performed extremely quickly and easily. At the same time, when the protective sheath is removed, there is no risk of damaging the optical fibers forming the cable body by applying an unreasonable load.

In addition, even after removing the protective sheath together with the cable support wire that gets in the way of indoor wiring, the cable body is loosely inserted and held in the binding layer that covers the outside of the cable over the entire length of the cable, so the cable that forms the cable body is Each optical fiber core wire does not become disjointed and tangled, and wiring work becomes extremely easy.

Furthermore, since the cable body is loosely inserted into the bundle layer, the bundle layer is cut in the radial direction over the centering length of the optical fiber core, and the cut portion is slid smoothly in the cable axial direction. It can be easily pulled out from around the cable body. Therefore,
There is no risk of damaging the optical fiber during centering.

〔Example〕

Hereinafter, embodiments of the present invention will be specifically described based on the drawings.

FIGS. 3 and 4 are a perspective view and a cross-sectional view of an example of a self-supporting fiber optic cable according to the present invention.

In the figure, 10 is a cable support line made of twisted wire, 11 is seven optical fiber core wires 12, 12...
A cable body 13 is a cable body 13 that is coated on the outside of the cable body 11 to form the cable body 1.
A binding layer 14 is a protective sheath that integrally covers the outside of the cable support line 10 and the binding layer 13.

That is, in the self-supporting optical fiber cable shown in this example, a binding layer 13 that loosely inserts and holds the cable body 11 and a protective sheath 14 that covers the binding layer 13 are formed by extrusion molding on the outside of the cable body 11. covered concentrically.

Further, the protective sheath 14 is formed with a connecting portion 15 that connects a portion that covers the binding layer 13 and a portion that covers the cable support line 10 to each other.

Between the binding layer 13 and the protective sheath 14 covering it, the cut portion of the protective sheath 14 cut in the radial direction together with the cable support wire 10 can be slid smoothly along the cable axis direction. A slight void 16 is formed.

However, when wiring this self-supporting optical fiber cable from outdoors to indoors,
As before, the entire protective sheath 14 together with the cable support wire 10 is cut in the radial direction at a portion corresponding to the wiring length of the cable body 11, and the cable body 1 is pulled while pulling the cut portion along the cable axis direction.
0 from around the binding layer 13.

At this time, since a gap 16 is formed between the binding layer 13 and the protective sheath 14 to the extent that the protective sheath 14 can smoothly slide in the cable axial direction, the cut protective sheath 14 can be moved with a relatively small force. It can be pulled out from the binding layer 13 easily and smoothly.

Therefore, it is possible to quickly and easily cut off the cable support wire 10 that gets in the way of indoor wiring, and at the same time, the light forming the cable body 11 can be cut with a blade that cuts the protective sheath 14 when performing the cutting work. Do not damage the fiber core wires 12, 12...
When removing the protective sheath 14, the optical fiber core 1
There is no need to worry about putting an unreasonable burden on 2, 12...

In addition, the cable body 11 has a wiring portion from which the protective sheath 14 has been cut out, and the cable body 11 has a binding layer 1 over its entire length.
3, and the optical fiber core 1 is covered in the middle of wiring.
Since the wires 2, 12, etc. do not fall apart and intersect with each other, there is no problem with the wiring work.

Furthermore, if the binding layer 13 is made of rubber or elastic synthetic resin, for example, it has good flexibility and is extremely convenient for wiring work, and at the same time, it acts as a protective sheath that acts as a buffer on its own during wiring work, allowing light to shine through. There is an advantage that the fiber core wires 12, 12, . . . are protected.

Furthermore, since the cable main body 11 is loosely inserted and held within the binding layer 13, when the cable main body 11 is wired and connected to communication equipment, terminal equipment, etc., the optical fiber core wires 12, 12 The binding layer 13 is cut in the radial direction at a portion corresponding to the centering length of .

Therefore, there is little risk of damaging the optical fibers 12, 12, . . . when centering the optical fibers 12, 12, . . . by cutting off the binding layer 13 by a predetermined length.

[Effect of idea]

As described above, according to the present invention, cable support wires that get in the way during indoor wiring can be fixed to the wiring length of the cable body without applying excessive force to the optical fiber core wires that make up the cable body. In addition to being able to quickly and easily cut out the cable support wire, it also prevents the optical fibers that make up the cable body from coming apart and becoming tangled when the cable support wire is cut, making wiring work easier and significantly improving work efficiency. It has a very good effect of improving.

Furthermore, there is also the excellent effect of being able to reliably prevent damage to the optical fibers that may occur during wiring work or centering work.

[Brief explanation of the drawing]

1 and 2 are perspective views and sectional views showing examples of conventional self-supporting optical fiber cables, and FIGS. 3 and 4 are perspective views and sectional views showing examples of self-supporting optical fiber cables according to the present invention. FIG. Explanation of symbols, 10... Cable support line, 11...
... Cable body, 12 ... Optical fiber core wire, 13
...Binding layer, 14...Protective sheath, 16...Void.

Claims (1)

[Scope of utility model registration request] A self-supporting cable in which a cable support line 10 made of a twisted wire or the like and a cable body 11 made of a plurality of optical fiber core wires 12 are kept parallel to each other and integrally covered with the same protective sheath 14. In the type optical fiber cable, the cable body 11
A binding layer 13 that loosely inserts and holds the cable body 11 and a protective sheath 14 that covers the binding layer 13 are concentrically coated on the outside of the cable body 11. Between the binding layer 13 and the protective sheath 14, the cable Support line 10
A self-supporting optical fiber cable characterized in that a gap 16 is formed to allow a cut portion of the protective sheath 14 cut in the radial direction to smoothly slide along the axial direction of the cable.