JPH0343782Y2 - - Google Patents

Description

[Detailed Description of the Invention] "Industrial Application Field" The present invention relates to a structure for reinforcing the pulling end of an optical fiber composite overhead ground wire to make it easier to hold when the overhead ground wire is being wired.

``Prior Art'' FIG. 2 shows an example of an optical fiber composite overhead ground wire 1, in which a steel It has a structure in which a plurality of aerial ground wires 4 made of wires coated with aluminum are twisted together.

Conventionally, when such an optical fiber composite overhead ground wire 1 is installed as an overhead wire, the tensioned end thereof is constructed as shown in the example of FIG. 3. That is, the optical fiber composite overhead ground wire 1 is covered with a rubber cover 11.
It passes through the protective cover 12, and a steel sleeve 14 integrated with the traction fitting 13 is placed on the end thereof and crimped, and the protective cover 12 is placed over the steel sleeve 14 as shown by the chain line and fixed.

``Problem that the invention attempts to solve'' By the way, after extending such optical fiber composite overhead ground line 1 between steel towers, etc., it is necessary to connect optical fiber unit 2 to other optical fibers using the connection box attached to the steel tower. However, in this case, since the optical fiber unit 2 has been damaged by the compression force of the steel sleeve 14, the steel sleeve 1
The optical fiber unit 2 is exposed in a protruding state by cutting off the portion covered with the optical fiber unit 2 and removing the overhead ground wire 4 and the metal pipe 3 at the tip, and connecting the connector to the exposed end. However, there is a problem in that the connection work after the line is extended becomes complicated.

The object of the present invention is to effectively protect an optical fiber unit from the gripping force during wire drawing, and to facilitate connection work after wire drawing.

``Means for Solving the Problems'' The pulled end of the present invention is such that the end of the optical fiber unit is exposed in a protruding state than the overhead ground wire and the metal pipe, and An internal gripping sleeve is inserted into the metal pipe at a position halfway than the tip of the metal pipe, and a compression sleeve is inserted around the overhead wire so as to extend in front and behind the internal gripping sleeve. A stepped portion that reduces the inner diameter is formed on the inner periphery of the tip, and the aerial ground wire is held in a bent state between the stepped portion and the tip of the internal gripping sleeve. A retainer for holding the overhead wire in a bent state is screwed to the end of the internal gripping sleeve, and a protective tube with a traction fitting is attached to the tip of the compression sleeve in the exposed state. This is a structure that can be detached and attached to accommodate an optical fiber.

``Operation'' In the tension end structure of the present invention, the aerial ground wire is held between an internal gripping sleeve fitted over the metal pipe and a compression sleeve around the aerial ground wire, and the optical fiber unit is attached to the optical fiber unit. In addition to preventing the application of a gripping force, the overhead ground wire is held in a bent state at the front and rear of the internal gripping sleeve by the stepped part at the front end of the compression sleeve and the retaining part screwed to the rear end. A strong gripping force is applied to the overhead wire, and the exposed optical fiber unit is housed in a protective tube to protect it from external forces during wire stretching, and the protective tube is removed after the wire is stretched. This makes it possible to easily connect optical fiber units.

"Embodiment" Hereinafter, one embodiment of the tension end structure of the optical fiber composite overhead ground wire according to the present invention will be described based on FIG. 1.

This optical fiber composite overhead ground wire 1 has an optical fiber unit 2 at its end exposed in a protruding state beyond the overhead ground wire 4 and the metal pipe 3, and a termination section is provided at the exposed end of the optical fiber unit 2. A connector 21 is connected via 20.

An internal gripping sleeve 22 made of steel is inserted between the aerial ground wire 4 and the metal pipe 3, and is fitted onto the metal pipe 3 at a position halfway retracted from the tip thereof. Sleeve 22
The outer peripheral surfaces of both ends thereof are formed into tapered surfaces 22a.

Further, a compression sleeve 23 made of steel and longer than the internal gripping sleeve 22 is fitted around the twisted aerial ground wires 4 . The compression sleeve 23 is provided so as to extend forward and backward of the internal gripping sleeve 22 .
A tapered stepped portion 23a is formed on the inner periphery of the distal end disposed in front of the internal gripping sleeve 22, and the inner diameter of the distal portion is reduced. The aerial ground wire 4 is sandwiched between them, and the aerial ground wire 4 is held in a bent state.

Further, a threaded portion 2 is provided at the rear end of the compression sleeve 23 at a position rearward of the internal gripping sleeve 22.
4, the retainer 25 is removably fitted. The retainer 25 has an inner diameter that is the same as the reduced diameter portion of the distal end of the compression sleeve 23, and a tapered surface 25a is formed on the inner peripheral surface of the distal end. 25a and the tapered surface 22a at the rear end of the internal gripping sleeve 22, the aerial ground wire 4 is held in a bent state.
A plug 26 is provided behind the retainer 25 so as to connect the outer circumferential surface of the retainer 25 and the outer circumferential surface of the aerial ground wire 4 in a gently tapered surface.

On the other hand, a coupling nut 27 is rotatably inserted into the distal end of the compression sleeve 23 and is locked between the flange 23b at the distal end of the compression sleeve 23 and a fixing nut 28 screwed onto the compression sleeve 23. A protective tube 29 is removably connected to the coupling nut 27.

The protective tube 29 has a laminated structure of a flexible metal tube 30 made of stainless steel or the like and a braided tube 31 made of stainless steel wire or the like, and the coupling nut 2 is attached to one end thereof.
A cylindrical base 32 screwed into the cylindrical base 7 is integrally provided, and a traction fitting 33 for locking a traction wire is connected to the other end.

Further, inside the protective tube 29, a hose 35 made of vinyl chloride or the like is stored in an inserted state with both ends sealed with plugs 34, and the exposed end of the metal pipe 3 is inserted into one of the plugs 34. The optical fiber unit 2 drawn out from the metal pipe 3 and the connector 21 at its tip are housed in the hose 35.

When assembling the tension end of such a structure, attach the plug 26 to the optical fiber composite overhead ground wire 1 in advance.
After inserting the stopper 25 and untwisting the aerial ground wire 4 at the tip and attaching the internal gripping sleeve 22 to the metal pipe 3, the aerial wire is inserted again from above the internal gripping sleeve 22. The wires 4 are twisted together and the compression sleeve 23 is extrapolated thereon.
Then, the compression sleeve 23 is pressed in the direction of its external insertion, so that the aerial ground wire 4 is sandwiched between the stepped portion 23a on the inner periphery of the tip and the tapered surface 22a at the tip of the internal gripping sleeve 22, By compressing the vicinity of the longitudinal center of the compression sleeve 23 from the outside, the aerial ground wire 4 is gripped with the internal gripping sleeve 22. Next, by screwing the retainer 25 into the rear end of the compression sleeve 23, the tapered surface 25a of the retainer 25 is tightened.
When the aerial ground wire 4 is sandwiched between the tapered surface 22a at the rear end of the internal gripping sleeve 22, the aerial ground wire 4 is held against the internal gripping sleeve by the stepped portion 23a of the compression sleeve 23 and the stopper 25. It is held in a bent state before and after 22. In this case, by screwing in the stopper 25, the compression sleeve 23 and the stopper 25 are in a state in which a pressing force is applied to both tapered surfaces 22a of the internal gripping sleeve 22 in opposing directions, and the aerial The sandwiched state of the wire 4 can be maintained reliably. Then, the optical fiber unit 2 and the connector 2 at its tip
1 is housed in the hose 35, the protective tube 29 is placed on the outside of the hose 35, and the cap 3 is closed.
2 is fixed to the tip of the compression sleeve 23.

After assembling the tensioned end in this way, when the optical fiber composite overhead ground wire 1 is to be connected to the overhead wire, the wire is wound around the traction fitting 33 and pulled. In this case, the protective tube 29 is When passing through a metal wheel etc. placed on the way of the wire, it can be bent to match the metal wheel etc., allowing smooth traction and protecting the optical fiber unit 2, connector 21 etc. from external force at that time. can be effectively protected. After the wire is stretched, the compression sleeve 2
At the same time as removing the protective tube 29 and the traction fitting 33 from 3, remove the hose 35, etc., and connect the connector 21 stored therein to another optical fiber in the connection box attached to the steel tower etc. It can be done.

That is, according to this tensioned end structure, during wire drawing, the internal gripping sleeve 22 and the compression sleeve 2
3 and the stopper 25 to grip the aerial wire 4 so as not to apply a gripping force to the optical fiber unit 2, and to bend the aerial wire 4 before and after the internal gripping sleeve 22. The optical fiber unit 2 and the connector 21 can be held in the protective tube 29 to protect them from friction when passing through the metal wheel. At the time of wire extension, the connector 21 can be connected to another optical fiber without any terminal processing by simply removing the protective tube 29, hose 35, etc. Note that the compression sleeve 23, the internal gripping sleeve 22, and the like may be left attached as they are even after the overhead wire is installed.

"Effects of the Invention" As explained above, according to the pulling end structure of the optical fiber composite overhead ground wire of the present invention, the following effects can be achieved.

(i) Since the aerial ground wire is held between the internal gripping sleeve fitted onto the metal pipe, the compression sleeve around the aerial ground wire, and the retainer, no gripping force is applied to the optical fiber unit. In addition, since the exposed end of the optical fiber unit is housed in the protective tube, the optical fiber unit can be effectively protected from external forces during wire drawing.

(ii) The stepped portion of the compression sleeve and the stopper keep the overhead wire bent before and after the internal gripping sleeve, and since the stopper is screwed into the compression sleeve, the inside A pressing force can be applied to both ends of the gripping sleeve in a direction facing the stepped portion and the retainer, and a strong gripping force can be applied to the aerial ground wire.

(iii) Since the optical fiber unit exposed from the overhead ground wire and metal pipe is housed in the protective tube during the wire extension, after the wire is wired, the traction fitting and the protective tube are removed from the compression sleeve. By simply using this method, the optical fiber unit can be exposed, and the terminal processing can be omitted, and the connection work after the wire is stretched can be facilitated.

[Brief explanation of the drawing]

Fig. 1 is a partially sectional front view showing an embodiment of the tensile end structure of the optical fiber composite overhead ground wire according to the present invention, and Fig. 2 is a sectional view showing an example of the optical fiber composite overhead ground wire. , FIG. 3 is a perspective view showing an example of a conventional structure. DESCRIPTION OF SYMBOLS 1... Optical fiber composite overhead ground wire, 2... Optical fiber unit, 3... Metal pipe, 4... Overhead ground wire, 20... Termination part, 21... Connector, 22
...internal gripping sleeve, 22a...tapered surface, 2
3...Compression sleeve, 23a...Stepped portion, 23b...
...Flange, 24... Threaded portion, 25... Stopper, 25a... Tapered surface, 26... Plug, 27
...Cup ring nut, 28...Fixing nut,
29...protective tube, 30...metal tube,
31... Braided tube, 32... Cap, 33...
Towing fittings, 34...plug, 35...hose.

Claims (1)

[Scope of utility model registration request] Metal pipe 3 housing optical fiber unit 2
In the optical fiber composite overhead ground line 1 formed by twisting a plurality of overhead ground wires 4 around the optical fiber unit 2, the optical fiber unit 2 at the end thereof is exposed in a protruding state than the overhead ground wire 4 and the metal pipe 3. At the same time, an internal gripping sleeve 22 is inserted between the aerial ground wire 4 and the metal pipe 3 in an externally fitted state on the metal pipe 3 at a position halfway drawn in from the ends thereof, and the inner gripping sleeve 22 is inserted between the overhead ground wire 4 and the metal pipe 3 in a state of fitting around the metal pipe 3. In this state, a compression sleeve 23 is fitted onto the inner gripping sleeve 22 so as to extend forward and backward, and a protective tube 29 having a pulling fitting 33 accommodates the exposed optical fiber unit 2 at the tip of the compression sleeve 23. The compression sleeve 23 is provided with a stepped portion 23a that reduces the inner diameter at the inner periphery of its distal end, and an air gap is formed between the stepped portion 23a and the distal end of the internal gripping sleeve 22. A retainer 25 is screwed to the rear end of the wire 4 to hold the wire 4 in a bent state, and to hold the aerial wire 4 in a bent state with the rear end of the internal gripping sleeve 22. A tensile end structure of an optical fiber composite overhead ground wire.