JPH08334630A - Method or tightening optical fiber cable - Google Patents

Abstract

PURPOSE: To prevent the sheath of an optical fiber cable from being damaged and the transmission loss of light of optical fibers from increasing. CONSTITUTION: A protective member 10 is mounted at the prescribed position on the outer periphery of the optical fiber cable 1 so as to cover the entire part of the outer periphery of the optical fiber cable 1. A wedge 3 for a cam along and the cam along 4 are mounted on the protective member 10 and thereafter, the can along 4 is pulled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for tightening an optical fiber cable.

[0002]

2. Description of the Related Art As shown in FIG. 3, conventionally, for example, in order to anchor an end portion of an optical fiber cable 1 to a supporting member 2 such as a steel tower, first, the optical fiber cable 1 is supported between the supporting members 2.
And then attach the cam along wedge 3 and the cam along 4 at a predetermined position on the end side of the optical fiber cable 1, and then pull the cam along 4 to bring the end portion of the optical fiber cable 1 to the supporting member 2 side. In this state, a pulling clamp (not shown) or the like is attached to the end portion of the optical fiber cable 1 so as to pull it. In the figure, 5 is a hoisting device for pulling the cam along 4 toward the support member 2, and 6 is the cam along 4 and hoisting device 5.
It is a connecting member that connects and.

In the above description, the case where the end portion of the optical fiber cable is anchored and fixed to the supporting member such as a steel tower has been described. However, when the intermediate portion of the optical fiber cable is supported by the supporting member such as a steel tower, Attach the wedge for cam along and cam along at the specified position of the optical fiber cable,
Thereafter, the optical fiber cable is supported by the support member by pulling the cam along.

[0004]

However, as described above, when the cam-along wedge 3 and the cam-along 4 are mounted at predetermined positions of the optical fiber cable 1 and then the cam-along 4 is pulled, the clamping force on the optical fiber cable 1 is increased. Therefore, there has been a problem that the sheath of the optical fiber cable 1 is deformed by this tightening force. That is, the cam-along wedge 3 is divided into two as shown in FIG. 4, and when the cam-along wedge 3 is attached to the outer circumference of the optical fiber cable 1, the cam-along wedge 3 is increased in order to increase the tightening force of the cam-along wedge. The wedge 3 is formed so as to have a gap at the joint 3A. For this reason, when the cam-along is pulled, the sheath of the optical fiber cable 1 protrudes into this gap. Further, when the cam along is pulled, the optical fiber itself arranged in the optical fiber cable is also deformed, which causes a problem that the transmission loss of light increases.

The above-mentioned problems are particularly serious when an optical fiber cable is a non-metallic optical fiber cable having neither a metal protective layer nor a metal tension member.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and provides an optical fiber cable which does not damage the sheath of the optical fiber cable and which does not increase the transmission loss of light in the optical fiber. To provide a method of tight binding, a protective member is attached to a predetermined position on the outer circumference of the optical fiber cable so as to cover the entire outer circumference of the optical fiber cable, and then a wedge for cam along and a cam along are mounted on the protective member. After that, it is characterized by pulling the come along.

[0007]

When a protective member is attached to a predetermined position on the outer circumference of the optical fiber cable so as to cover the entire outer circumference of the optical fiber cable, and a cam-along wedge is mounted on the protective member.
Even if a gap is formed at the joint of the cam-along wedge that is split in two, the sheath of the optical fiber cable is not deformed because the entire outer periphery is covered with the protective member. Further, since the pulling force of the cam along is dispersed by the protective member, local stress is not concentrated on the optical fiber cable. Therefore, the optical fiber itself arranged in the optical fiber cable is not deformed, and the optical transmission loss is not increased.

[0008]

The present invention will be described in detail below with reference to the drawings. 1 and 2 show an embodiment of the present invention. In the present invention, first, the optical fiber cable 1 is extended between the support members 2, and then the cam along wedge 3 and the cam along 4 are mounted at predetermined positions of the optical fiber cable 1,
Thereafter, the cam along 4 is pulled to draw the end portion of the optical fiber cable 1 toward the support member 2 side, and a retracting clamp (not shown) or the like is attached to the end portion of the optical fiber cable 1 in this state as in the conventional method. However, in the present invention, before attaching the wedge 3 for the cam along,
The protective member 10 is attached to the outer periphery of the optical fiber cable 1 so as to cover the outer periphery of the optical fiber cable.
The wedge 3 for cam along is attached on top of 0.

In the embodiment, an armor rod 11 is used as the protective member 10 as shown in FIG. That is, the armor rod 11 is tightly wound around the outer circumference of the optical fiber cable at the position where the cam-along wedge 3 is mounted. Therefore, the entire outer circumference of the sheath of the optical fiber cable is covered with the armor rod 11 which is the protection member 10.

As a material for the armor rod 11, aluminum alloy, aluminum-coated steel wire or the like can be used. The inner diameter is formed to be slightly smaller than the outer diameter of the optical fiber cable 1 so that the optical fiber cable 1 does not move when wound around the optical fiber cable 1.

The winding length of the armor rod 11 is
It is preferable that the length is equal to or more than twice the length of the cam-along wedge 3 in order to disperse the force applied to the optical fiber cable. Further, in order to prevent the armor rod 11 from sliding on the outer circumference of the optical fiber cable 1, it is preferable to apply a polishing material between the armor rod 11 and the optical fiber cable 1. The application position of the polishing material may be the entire contact portion between the armor rod 11 and the optical fiber cable 1 or a part thereof, but it is necessary to apply the polishing material at least at the position where the cam along wedge 3 is attached to prevent slippage. From the point of, it is preferable.

As described above, after the armor rod 11 which is the protection member 10 is attached to the optical fiber cable 1 at a predetermined position, the cam along wedge 3 and the cam along 4 are mounted, and then the cam along 4 is pulled. When pulled, the armor rod 11 covers the entire outer circumference of the optical fiber cable, so that the sheath of the optical fiber cable 1 is not deformed. Further, since the pulling force of the cam along 4 is dispersed by the armor rod 11, local stress is not concentrated on the optical fiber cable,
The optical fiber in the optical fiber cable is not deformed. do not do.

Next, specific examples of the present invention will be described. A non-metallic optical fiber cable with an outer diameter of 14.9 mm has a wire diameter of 2.5 mm and a length of 1000 m on the outer circumference.
Seventeen steel armor rods each having an inner diameter of 14.6 mm and having a steel wire of m were closely wound. Next, in the center of the armor rod in the longitudinal direction, an inner diameter of 19.9 mm and a length of 3
A 00 mm wedge for cam along was attached, a conical cam along was attached to the outer periphery of the wedge, and the cam along was pulled up to the tower side by a hoisting device to perform a tight line work. Tension tension is 19.6 KN. The optical transmission loss of the optical fiber cable during the wire-tightening work and the outer diameter of the optical fiber cable before and after the wire-tightening work were measured.

For the purpose of comparison, the wire tight work is carried out without the armor rod attached, the optical transmission loss of the optical fiber cable during the wire tight work and the outer diameter of the optical fiber cable before and after the wire tight work. Was measured.

Table 1 shows the measurement results of the above tests. The outer diameter of the optical fiber cable is the value measured at two locations by changing the position in the same direction at right angles. The smaller the difference between the measured values, the closer the outer diameter of the optical fiber cable is to a perfect circle. The larger the opening, the larger the deformation of the outer diameter of the optical fiber cable.

[0016]

[Table 1]

As is apparent from the above table, in the present invention, no light transmission loss of the optical fiber cable occurs during the wire-tightening operation. Further, the fluctuation of the outer diameter of the optical fiber cable after the wire tightening work is small, and the outer diameter of the optical fiber cable is hardly deformed even after the wire tightening work. On the other hand, in the comparative example, a large optical transmission loss of the optical fiber cable occurs during the wire-tightening work, and the outer diameter variation of the optical fiber cable after the wire-tightening work is also large, and the optical fiber cable is It is greatly deformed.

Although the armor rod is used as the protective member in the above embodiment, the protective member may be a rolled metal plate or plastic plate.

[0019]

As described above, according to the method of tightly connecting an optical fiber cable according to the present invention, the transmission loss of light of the optical fiber cable does not occur during the tight wire work, and after the tight wire work. Also, the sheath of the optical fiber cable is not deformed.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of the present invention.

FIG. 2 is an enlarged front view of a main part of the present invention.

FIG. 3 is a front view showing a conventional example.

FIG. 4 is an enlarged front view of a conventional main part.

[Explanation of symbols]

 1 Optical fiber cable 2 Support member 3 Wedge for cam along 4 Cam along 5 Winding device 10 Reinforcing member 11 Armor rod

Claims (1)

[Claims] 1. A protective member is attached to a predetermined position on the outer circumference of an optical fiber cable so as to cover the entire outer circumference of the optical fiber cable, and then a wedge for cam along and a cam along are mounted on the protective member, and then the cam along. A method for tightening an optical fiber cable, wherein the optical fiber cable is tightened to a support member by pulling.