JPH0455285Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an optical fiber cable jumper device in a jumper section where a composite overhead ground wire to which an optical fiber cable is attached is held on both sides of a steel tower.

[Conventional technology] A composite overhead ground wire is installed on both sides of the steel tower, in which a rigid and heat-resistant optical fiber cable coated with FRP (glass fiber reinforced plastic) is attached to an overhead ground wire and held with gripping metal fittings. In the jumper part to be held down, the optical fiber cable separated from the composite overhead ground wire is stretched loosely between the holding parts of both overhead ground wires, which are held on both sides of the tower by the holding fittings.

[Problems to be solved by the invention] The jumper section of this optical fiber cable is subject to the shaking of the overhead ground wire due to wind pressure, and the slackened jumper section itself sways violently due to the wind pressure, resulting in contact with the steel tower and damage. There is a risk that local bending stress may cause damage to the gripping portions at both ends of the optical fiber cable jumper portion.

In practical use as a retaining clamp to prevent the optical fiber cable from colliding with foreign objects or damage due to lightning damage at the jumper part of a composite overhead ground wire with a built-in optical fiber cable, in which an optical fiber cable is installed at the center of the overhead ground wire. Like No. 57-41422,
Cover the steel clamp for pulling out the optical fiber cable with the aluminum clamp for connecting the jumper wire, screw the optical fiber cable cap into the hole of this steel clamp, attach the metal sealed protection pipe to this cap, and tighten the center hole of the retaining clamp. A retaining clamp for an overhead ground wire containing an optical fiber cable is known, which protects the optical fiber cable from damage from foreign objects and lightning by inserting the optical fiber cable into a metal protection pipe and pulling it out. There is.

The above-mentioned retaining clamp has a complicated structure in order to pull out the optical fiber cable built in the center of the overhead ground wire from the cut end of the overhead ground wire. Because the fiber optic cable must be assembled and pulled out, it takes a considerable amount of time and effort, and the optical fiber cable must be cut before it can be separated from the overhead ground wire, inserted into the retaining clamp, and pulled out. There is a problem.

Additionally, the present applicant has developed a steel tower lead-in section for an overhead optical cable attached to an overhead line in Japanese Patent Application Laid-Open No. 58-150910, in which a corrugated metal pipe or plastic pipe was used as a protection pipe for the optical cable. When a metal pipe is used, flexibility and handling are not always sufficient, and when a plastic pipe is used, it is not always sufficient to prevent damage to the optical cable, so further improvements have been desired.

In addition, the applicant has also proposed a method for laying an optical fiber cable by drawing it into a rubber/plastic tube with drainage holes that is integrally supported by the messenger wire.
No. 59-90911, a cable conduit for laying optical fiber cables overhead was developed, but this cannot be used for the jumper section of optical fiber cables attached to overhead ground wires.

The present invention provides a jumper device for an overhead optical fiber cable attached to an overhead ground wire, which can reliably prevent damage to the optical fiber cable at the jumper part as described above, and does not require much labor and time for work at the construction site. The purpose is to provide

[Means for Solving the Problems] In order to achieve the above object, the jumper device of the present invention for an overhead fiber optic cable attached to an overhead ground wire is provided in which a composite overhead ground wire in which an optical fiber cable is attached to an overhead ground wire is attached to a steel tower. At the jumper portion held down by the holding clamps 8, 8 on both sides, the overhead ground wire gripping portion 3a
Using the optical fiber cable separation fittings 3, 3 having optical fiber cable branch pipe attachment parts 3b, grip the optical fiber cable composite overhead ground wires 2, 2 with the respective overhead ground wire gripping parts 3a, 3a, and Each optical fiber cable 4, 4 attached to each overhead ground wire 2, 2 is passed through the branch pipe attachment part 3b, 3b of each separation fitting 3, 3, and the overhead ground wire 2, 2
The jumper part 4' of the optical fiber cable is formed by separating the fiber optic cable between the two separated separation fittings 3, 3, and forming a jumper part 4' of the optical fiber cable. A rubber optical fiber cable branch pipe 5 with molded stranded wires 5' is placed over the loosened optical fiber cable jumper part 4', and both ends of this pipe are connected to the branch pipe attachment parts of each of the separation fittings 3, 3. 3b and 3b to form a jumper device.

[Function] The optical fiber cable separation fitting 3 has its overhead ground wire gripping section 3a and optical fiber cable branch pipe attachment section 3b to separate the optical fiber cable without cutting the optical fiber cable attached to the overhead ground wire. to hold the end of the branch pipe 5.

The optical fiber cable branch pipe 5 has sufficient strength and appropriate flexibility by molding steel stranded wires 5' into a rubber pipe, and even if it swings and comes into contact with a steel tower member, the optical fiber cable inside will not be damaged. It is possible to protect the branch pipe and reliably prevent damage, and it is safe even if local bending stress is applied to both ends of the branch pipe.In addition, by having the slit 5a in the length direction, the branch pipe can be attached to an overhead ground wire. It becomes possible to cover the jumper part without cutting the optical fiber cable.

[Examples] Examples of the present invention will be described below with reference to the drawings. In the embodiment shown in the first diagram, 2, 2 is an overhead ground wire;
Reference numerals 4 and 4 are optical fiber cables with rigidity and heat resistance such as FRP coated optical fiber cables, and the optical fiber cables 4 are attached to the outer surface of the overhead ground wire 2 and held with the gripping fittings 9 to be attached to the overhead wires. A fiber optic cable is configured. 7 is a steel tower, and the above-mentioned overhead ground wires 2, 2 are attached with retaining clamps 8,
He was held back at 8. Reference numerals 1 and 1' designate the anchoring portions of the overhead ground wires 2 and 2 on both sides of this tower.

3, 3 is an optical fiber cable separation fitting;
It has an overhead ground wire gripping part 3a and an optical fiber cable branch pipe attachment part 3b, and is gripped by the overhead ground wire gripping parts 3a on each overhead ground wire part near the retaining clamps 8, 8 on both sides of the steel tower 7. Attach separation fittings 3 and 3. The optical fiber cable 4 attached to the overhead ground wire 2 is separated from the overhead ground wire 2 by sandwiching it between the branch pipe attachment portions 3b of this separation fitting 3, and is held in place by retaining clamps 8, 8 on both sides of the steel tower. A jumper section 4' of the optical fiber cable is formed by providing a predetermined slack in the optical fiber cable section between the two anchoring sections 1 and 1'.

Reference numeral 5 designates an optical fiber cable branch pipe, which is molded, for example, from chloroprene rubber with a shore hardness of about 30 to 40, and stranded steel wires 5' are molded inside the pipe wall as shown in the cross-sectional view in Figure 2, and slits are formed in the length direction. 5a
The inner diameter of the pipe is approximately 5 mm larger than the outer diameter of the optical fiber cable. The jumper section 4' of the optical fiber cable is inserted into the pipe through the slit 5a of the branch pipe 5, and the branch pipe attachment section 3b of the separation fitting 3 is attached to both ends of the branch pipe 5 to the overhead ground wire sections on both sides of the steel tower. Then, the branch pipe 5 is loosened and placed over the loosened optical fiber cable jumper portion 4'. The optical fiber cable branch pipe 5 thus placed over the optical fiber cable jumper portion 4' is fixed to the steel tower 7 with fixing fittings 6, 6 such as U-bolts.

If the hardness of the rubber pipe of this branch pipe 5 is too small, it may bend beyond the allowable radius of curvature of the loosened optical fiber cable jumper section 4' and break the internal optical fiber cable. Fiber cable jumper section 4'
Since the work of covering the surface becomes difficult, it is appropriate to set the shore hardness to about 30 to 40. Since the branch pipe 5 is made of rubber, it can be easily attached to the optical fiber cable jumper section, and the stranded steel wire 5' is molded inside to strengthen the bending strength.

Steel strands 5' are placed inside the rubber pipe wall as described above.
By covering the optical fiber cable jumper part 4' with the branch pipe 5 molded with the above, the internal optical fiber cable will not be damaged even if this jumper part swings due to wind pressure etc. and comes into contact with the steel tower member.
It is safe even if local bending stress is applied to both ends of the branch pipe, and the work of covering the branch pipe 5 over the optical fiber cable jumper section 4' can be accomplished by inserting the optical fiber cable inside through the longitudinal slit 5a. Therefore, it becomes possible to cover the optical fiber cable attached to the overhead ground wire over the jumper portion without cutting it.

The embodiment shown in FIG. 3 is an embodiment in which a junction box 10 containing a connecting part of the optical fiber cable is provided in the middle of the jumper part 4' of the optical fiber cable shown in the first diagram, and this junction box 10 is fixed to the steel tower 7. This is an example, and the same reference numerals as in FIG. 1 indicate the same parts. In this embodiment as well, optical fiber cable separation fittings 3, 3 are attached to each overhead ground wire portion near the detention clamps 8, 8 on both sides of the steel tower 7, and the optical fiber cable 4 attached to the overhead ground wire 2 is connected to the separation fittings 3. A jumper part 4' is formed between the stop parts 1 and 1' by separating it from the overhead ground wire 2 at the branch pipe attachment part 3b, and a stranded steel wire 5' is molded on this optical fiber cable jumper part 4', and the slit 5a is formed. By covering the optical fiber cable branch pipe 5 made of rubber and having both ends of the pipe supported by the branch pipe attachment part 3b of the separation fitting 3, the optical fiber cable jumper part 4'
It is the same as in the embodiment shown in the first figure that the pipe 5 is protected by the branch pipe 5.

[Effects of the invention] As described above, the present invention has an overhead ground wire gripping portion and an optical fiber cable branch pipe attachment portion in a jumper portion that holds a composite overhead ground wire in which an optical fiber cable is attached to an overhead ground wire to a steel tower. Grip the composite overhead ground wire with the optical fiber cable separation fitting, separate the optical fiber cable from the overhead ground wire at the branch pipe attachment part of the separation fitting to form a jumper part of the optical fiber cable, and cut a longitudinal slit. A rubber optical fiber cable branch pipe with molded steel strands was placed over the optical fiber cable jumper section, and both ends of the pipe were attached to the branch pipe attachment section of the separation fitting, so the jumper section covered with the branch pipe would not sway due to wind pressure, etc. The internal optical fiber cable will not be damaged even if it comes into contact with a steel tower member, and it is safe even if there is local bending stress at both ends of the branch pipe. The work of forming a branch pipe and covering it with a branch pipe can be performed without cutting the optical fiber cable attached to the overhead ground wire.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing one embodiment of the present invention, FIG. 2 is a sectional view of an optical fiber cable branch pipe, and FIG. 3 is a diagram showing another embodiment. 1, 1'... Detention part, 2... Overhead ground wire, 3...
Optical fiber cable separation fitting, 3a... overhead ground wire gripping part, 3b... optical fiber cable branch pipe attachment part, 4... optical fiber cable, 5... optical fiber cable branch pipe, 5a... slit,
5'... Steel stranded wire, 7... Steel tower, 8... Detention clamp.

Claims (1)

[Scope of utility model registration request] The overhead ground wires 2, 2 held on both sides of the steel tower by the retaining clamps 8, 8 are connected to the respective overhead wires 3, 3 of the optical fiber cable separating fittings 3, 3 having the overhead ground wire gripping part 3a and the optical fiber cable branch pipe attachment part 3b. Each of the above-mentioned overhead ground wires 2,
The optical fiber cables 4, 4 attached to
The optical fiber cable is separated from the overhead ground wires 2, 2 by passing it through the cable, and the optical fiber cable portion between the two separated separation fittings 3, 3 is loosened to form a jumper portion 4', which has a longitudinal slit 5a. Stranded steel wire 5' inside the pipe wall
A molded rubber optical fiber cable branch pipe 5 is attached to the optical fiber cable jumper section 4'.
A jumper device for an overhead optical fiber cable attached to an overhead ground wire, in which both ends of the pipe are attached to the branch pipe attachment portions 3b, 3b of the respective separation fittings 3, 3.