JPH041528Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention is an optical communication cable, particularly an overhead wire attached type optical communication cable suitable as a signal transmission line attached to an overhead ground wire or other overhead wire. It's about cables.

[Prior art and its problems]

In recent years, optical communication lines have been attached to overhead lines such as overhead ground wires, overhead power transmission lines, and shielding lines (e.g., ground wires that serve as support wires,
Consideration is being given to installing them in parallel to shielding lines (or wrapping them in a spiral) to communicate with substations and power plants, or to monitor steel towers.

Conventionally, overhead line-attached optical communication cables used under such conditions are as shown in Figure 4.
A plurality of optical fiber core wires 4 are arranged in parallel, and these are collectively covered with a protective layer 5 made of an insulating material.
It is known that the cable is further covered with a belt-shaped sheath 2 made of insulating resin so that the cross section of the entire cable is flat. (Cable thickness) is small, so it is suitable as an overhead wire attached type.

However, the above method does not take into consideration the structure for branching the optical fiber core 4, so even if it becomes necessary to branch some of the optical fiber core 4 from the middle of the overhead line, it will not be possible to meet the demand. It was impossible to answer.

In consideration of this point, conventionally, as shown in FIG. An overhead wire-attached optical communication cable with a flat cross section has been proposed, which is made by arranging two optical fiber branch lines 1B in parallel and covering them all together with a band-shaped sheath 2.

According to this, since the optical fiber branch line 1B is prepared in advance in the cable, it is possible to take out the optical transmission signal from the middle of the overhead line at any time, but there is no risk of damaging the optical fiber branch line 1B. It is not easy to incise the sheath 2 without cutting, and it takes a lot of effort, so there is a problem that the workability of removing the branch is poor.

This idea was proposed in view of the above circumstances.
The purpose is to improve the workability of branching optical fibers midway through the installation route.

[Means for solving problems]

In an overhead wire-attached optical communication cable in which optical fiber trunk lines and optical fiber branch lines are arranged in a line parallel to each other and collectively covered with a band-shaped outer sheath, a non-metallic outer sheath tearable material is included in the sheath. A wire rod and a reinforcing wire rod having an outer diameter equal to or larger than the fiber trunk line and the optical fiber branch line are embedded along the length direction of the cable, and the reinforcing wire rod is embedded in the sheath in the width direction. The sheath tearing wire is disposed outside the optical fiber main line and the optical fiber branch line, and the sheath tearing wire is disposed further outside the reinforcing wire.

[Effect]

By pulling the sheath tearing wire outward in the width direction of the cable, the sheath can be torn and the optical fiber can be branched out.
In addition, when the sheath is torn by pulling the sheath tearing wire, the sheath is compressively deformed inward in the width direction, and a compressive force is generated inward of the sheath. Since it is received by the reinforcing wire located next to the tearing wire, the compressive force is prevented from acting on the optical fiber main wire or the optical fiber branch wire located further inside in the sheath width direction.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

1 and 2 show a first embodiment of the present invention.

This cable consists of multiple optical fiber cores 4
are arranged in parallel and collectively covered with a protective layer 5A to form an optical fiber main line 1A, and on one side in the arrangement direction, an optical fiber branch is formed by individually coating the optical fiber cores 4 with a protective layer 5B. line 1B
Further, a reinforcing wire 6 having an outer diameter equal to or larger than the main line 1A and the branch line 1B is arranged on both sides of the main line 1A and the branch line 1B on the outside in the sheath width direction. At the same time, a sheath tearing wire 3 made of a non-metallic material with high tensile strength, such as polyester, is provided at a portion further outward in the sheath width direction than the reinforcing wire 6, and these are attached to the belt-shaped outer sheath 2. It has a structure that is covered all at once.

In the overhead wire-attached optical communication cable constructed in this way, as shown in FIG. By tearing the outer sheath 2, the optical fiber branch line 1B can be easily pulled out and branched from the torn part. In particular, the sheath tearing wire 3 is provided further outside the reinforcing wire 6 in the sheath width direction, and the outer diameter of the reinforcing wire 6 is equal to or equal to that of the optical fiber main line 1A and the optical fiber branch line 1B. Since the above value is set, the compressive force accompanying the compressive deformation of the sheath 2 that occurs when tearing the sheath 2 is absorbed by the reinforcing wire 6, and therefore, the optical fiber main line 1A and the optical fiber branch line 1B are Without being compressed by the compression force, it is possible to effectively prevent excessive side pressure from acting on them.

FIG. 3 shows a second embodiment of the present invention, in which the sheath tearing wire 3 is provided only on the side where the optical fiber branch line 1B is present.

In this case as well, the outer sheath 2 is torn by pulling the outer sheath tearing wire 3 toward the outside in the sheath width direction as shown by the arrow in the figure, and the optical fiber branch line 1B is branched. At the same time, it is possible to effectively prevent the compressive force accompanying the compressive deformation of the sheath 2 during tearing from acting on the optical fiber branch line 1B.

[Effect of idea]

As is clear from the above, according to the present invention, it is possible not only to improve the workability of branching and extracting optical fiber wires, but also to ensure that there is no possibility that the compressive force generated when tearing the sheath will act on the optical fiber and have an adverse effect on it. It is something that can be eliminated.

[Brief explanation of the drawing]

1 and 2 are cross-sectional views showing a first embodiment of the present invention in a normal state and a torn outer sheath state, respectively, and FIG. 3 is a cross-sectional view showing a second embodiment of the present invention. , FIG. 4, and FIG. 5 are cross-sectional views showing conventional overhead line-attached optical communication cables, respectively. 1A... Optical fiber trunk line, 1B... Optical fiber branch line, 2... Outer sheath, 3... Wire rod for tearing the sheath, 6... Reinforcement wire rod.

Claims (1)

[Scope of utility model registration request] Optical fiber main line 1A and optical fiber branch line 1
In an overhead line-attached optical communication cable in which fibers B are arranged parallel to each other and collectively covered with a band-shaped external sheath 2, a sheath tearing wire 3 made of a non-metallic material and the optical fiber main line are disposed within the sheath 2. 1A
and a reinforcing wire 6 having an outer diameter equal to or larger than that of the optical fiber branch line 1B is embedded along the length direction of the cable, and the reinforcing wire 6 An overhead wire-attached optical communication cable, characterized in that it is disposed outside the fiber main line 1A and the optical fiber branch line 1B, and the sheath tearing wire 3 is disposed further outside the reinforcing wire 6. .