JPH1020163A - Cable for leading in by pneumatic feeding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the need for work for removing a sheath and the need for providing the cable with protecting means, such as closures, by stranding plural pipes consisting of weather resistant materials on the circumference of a tension member. SOLUTION: Plural pieces of the pipes 6 are stranded the tension member 4 on and are integrated and fixed thereto, by which this cable for leading in by pneumatic feeding is formed. The insertion passages for optical fibers or optical fiber unit are constituted in the pipes 6 of this cable. The pipes 6 are formed of the weather resistant materials, i.e., materials which are hardly deteriorated by the influence of UV rays, etc. More specifically, these materials include resins, etc., formed by compounding carbon with resins, such as polyethylene(PE) and resins formed by compounding UV absorbents with these resins. The PE compounded with the carbon is more preferable. The PE compounded with the carbon is formed by compounding and dispersing the carbon black having an average grain size of 10 to 60μm at 0.5 to 3wt.% with the PE.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cable for pneumatic feeding and drawing for inserting an optical fiber or an optical unit by pneumatic feeding.

[0002]

2. Description of the Related Art A pneumatic cable is laid beforehand between telephone poles and in buildings where optical fibers and optical units will be required in the future, and it is necessary to actually use the cable at a later date. At this point, an optical fiber or an optical unit is inserted into the insertion passage provided in the cable for pneumatic feeding and drawing and introduced. As a method of inserting an optical fiber or an optical unit into the insertion passage,
At the same time as sending an optical fiber or an optical unit from the entrance, air is blown at a high speed, and the optical fiber or the optical unit is put on the air flow and travels.

FIG. 3 shows an example of a conventional cable for pneumatic feeding and drawing. Reference numeral 4 denotes a tensile member such as a messenger wire, which is formed by coating the steel stranded wire 2 with polyethylene or the like. Around this tensile member 4, a plurality of polyethylene pipes 6 '...
Are gathered, on which the holding tape 8 is wound and integrated. Further, a sheath 10 made of vinyl chloride resin or the like is placed on the holding tape 8.
Are provided to constitute this pneumatic feeding and drawing cable. In the pneumatic feeding and drawing cable, the pipes 6 ′... Serve as insertion paths for optical fibers or optical fiber units.

When the above-described cable for pneumatic feeding and drawing is branched, the sheath 10 and the holding tape 8
, The branching operation of the pipes 6 '... Is performed, and then the pipe 6' at the portion where the sheath 10 has been removed.
... so that it is not deteriorated by the influence of ultraviolet rays, etc.
It is common to protect it by putting it in a closure or the like.

[0005]

However, in the branch of the cable for pneumatic feeding and drawing, the sheath 1
The operation of removing 0 is troublesome and requires skill, and in some cases, even the pipes 6 '... Disposed below the sheath 10 and the holding tape 8 may be damaged.
Further, there is a problem that a protection means such as a closure is always required, space efficiency is low, and cost reduction is difficult.

The present invention has been made in view of the above circumstances, and provides a pneumatic feed cable which does not require a sheath removing operation and does not need to provide a protection means such as a closure at a branch of the pneumatic feed cable. The purpose is to provide.

[0007]

In the cable for pneumatic feeding and drawing in according to the present invention, the solution to the above problem is to twist a plurality of pipes made of a weather-resistant material around a tensile member. Further, a holding wire such as a lashing wire may be wound after twisting the plurality of pipes.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an example of a pneumatic feed / in cable according to the present invention. FIG. 1 (a) is a sectional view, and FIG. 1 (b) is a side view. Reference numeral 4 denotes a tensile body, and here, a messenger wire in which seven strands of strands are twisted together and coated with polyethylene or the like is used. A plurality of pipes 6... Are twisted and integrated and fixed on the tensile member 4 to form a cable for pneumatic feeding and drawing. In this pneumatic feeding and retracting cable, the pipe 6 ...
The inside is an insertion path for an optical fiber or an optical fiber unit.

The pipes 6 are made of a weather-resistant material, that is, a material which is hardly deteriorated by the influence of ultraviolet rays or the like. Specifically, a resin in which carbon is mixed with a resin such as polyethylene, a resin in which an ultraviolet absorber is mixed, and the like can be exemplified. However, carbon-containing polyethylene is preferable in terms of cost. The carbon-containing polyethylene is obtained by mixing and dispersing 0.5 to 3% by weight of carbon black having an average particle size of 10 to 60 μm with polyethylene. In the above-described cable for pneumatic feeding and drawing, a messenger wire is used as the tensile member 4, but there is no particular limitation as long as it is a tensile material having an appropriate strength.

The steel stranded wire 2 has an outer diameter of 3 to 6 mm obtained by twisting a plurality of strands having an outer diameter of 1 to 2 mm. Is 5 to 27 mm
It is said. The inner diameter of the pipe 6 is 2 to 3 mm, and the outer diameter thereof is 3 to 5 mm. The number of the pipes 6 is 6 to 20. The outer diameter of the cable for pneumatic feeding and drawing is 12 to 37 mm.

FIG. 2 shows another example of the pneumatic feeding and drawing cable of the present invention. FIG. 2 (a) is a sectional view and FIG.
(B) is a side view. The difference between the pneumatic feeding cable and the pneumatic feeding cable shown in FIG. 1 is that the pipes 6...
The point is that a presser winding wire 12 such as a lashing wire is wound from above the pipes 6 at regular intervals. As shown in FIG. 1, the pipes 6 may be merely twisted. However, by winding the holding wire 12 and holding the pipes 6 from above, the pipes 6 are more stable. And integrated and fixed. The lashing wire used as the holding wire 12 has a diameter of 0.3 to 0.5 mm obtained by coating a steel wire or the like with polyethylene or the like.
Is a small diameter wire. The holding wire is not limited to this lashing wire, but has appropriate strength,
What is necessary is just to be able to be easily wound on top.

In the pneumatic feeding and drawing cable shown in FIGS. 1 and 2 described above, since the pipes 6 are formed of a weather-resistant material, ultraviolet rays or the like can be provided without providing a sheath thereon. No deterioration due to the influence of
For this reason, when branching the cable for pneumatic feeding and drawing, unlike the related art, it is not necessary to remove the sheath or the like, the working time is shortened, and there is no fear of damaging the pipes 6. Further, since a protection means such as a closure is not required, space can be saved and cost can be reduced.

Further, since no sheath is provided, the individual pipes 6 can be easily pulled out. Therefore,
Shortly before the branch point (drop point) of the cable for pneumatic feeding and drawing, the middle of one pipe 6 forming the pipe aggregate is cut, and this cut portion is pulled out from the pipe aggregate to the branch point (drop point). It can also be used for dropping. However, if the strength of the drawn-out pipe 6 is insufficient, a suitable tensile body is vertically attached to the pipe 6 and wound, or a support wire for dropping is laid.
An operation such as winding the pipe 6 is required.

[0014]

As described above, in the pneumatic feeding and drawing cable according to the present invention, since the pipe is formed of a weather-resistant material, even if a sheath is not provided thereon, the pipe is deteriorated by the influence of ultraviolet rays or the like. Never do. For this reason, when branching the pneumatic feed cable,
Unlike the related art, there is no need to remove the sheath and the like, the working time is shortened, and there is no fear of damaging the pipe. Further, since a protection means such as a closure is not required, space can be saved and cost can be reduced.

Further, since no sheath is provided, each pipe can be easily pulled out. Therefore, just before the branch point (drop point) of the cable for pneumatic feeding and drawing, the middle of one pipe forming the pipe aggregate is cut, and this cut portion is pulled out from the pipe aggregate to the branch point (drop point). Therefore, it can be used for dropping, and branching can be easily performed.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view and a side view of an example of a cable for pneumatic feeding and drawing of the present invention.

FIG. 2 is a cross-sectional view and a side view of another example of the pneumatic feed / in cable according to the present invention.

FIG. 3 is a cross-sectional view of an example of a conventional pneumatic feeding and drawing cable.

[Explanation of symbols]

2 ... steel stranded wire, 4 ... tensile body (messenger wire), 6 ... pipe, 12 ... holding wire (lashing wire)

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Suehiro Miyamoto 1440, Musaki, Sakura City, Chiba Prefecture Inside Fujikura Sakura Plant

Claims (2)

[Claims] 1. A pneumatic feed-in cable, wherein a plurality of pipes made of a weather-resistant material are twisted around a tensile body. 2. A cable for pneumatic feeding and drawing, wherein a plurality of pipes made of a weather-resistant material are twisted around a tensile body, and a holding wire is wound thereon.