JPH0228482Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention connects an optical fiber composite overhead ground wire made by twisting multiple metal wires to the outside of a metal pipe containing an optical fiber and a rod-shaped spacer. It is related to the retaining structure that retains the box.

[Conventional technology]

Generally, as shown in FIG. 1, the optical fiber composite overhead ground wire 1 is installed in a metal pipe 2 disposed at the center of a ground wire 5 made of a plurality of twisted metal wires 5a, as shown in FIG. As shown in FIG.
It is constructed by accommodating an optical fiber cable 3 coated with. As a connection structure for interconnecting optical fiber composite overhead ground wires 1 having such a configuration in a tower span section, the one shown in FIG. 3 is known. As shown in this figure, each line 5 in the left and right optical fiber composite overhead ground wires 1 to be connected
An appropriate length of the metal pipe 2 is exposed from the end of the metal pipe 2, and the optical fibers 3a drawn out from the end of each metal pipe 2 are connected to each other in a slack state, and the tension members 3b are connected in a straight line. There is. A disk-shaped spacer 7 is fixed to the exposed portion 2a of each metal pipe 2, and an optical fiber 3a is attached to this spacer 9.
A protective tube 10 that covers the connection part of the tension member 3b
are attached with bolts 11, and the inner space of the protection tube 10 is filled with a watertight filler 16. Further, the left and right optical fiber composite overhead ground wires 1 are connected to each other by a connecting filament (not shown).

[Problem that the invention attempts to solve]

Incidentally, in recent years, as shown in FIG. 4, a rod-shaped spacer 21 having a plurality of grooves 21a formed on its outer peripheral surface and an optical fiber 3a arranged in each groove 21a are accommodated in a metal pipe 20. So-called spacer-type optical fiber cables have been developed, but such spacer-type optical fiber cables have sufficient strength to withstand external compression forces, and also have a high resistance to external compression forces. This has the advantage that the optical fiber 3a can be protected. Therefore, a plurality of metal wires 5a are placed on the outside of the spacer type optical fiber cable.
Optical fiber composite overhead ground wire 23 made by twisting
When connecting to each other in the tower span, the third
It is not appropriate to adopt the conventional connection structure shown in the figure as is. This is because the conventional connection structure shown in FIG. 3 is suitable when the metal pipe 2 and the optical fiber cable 3 are relatively weak against external compressive force. Here, each end of the adjacent optical fiber composite overhead ground wires 23 is fixed to a junction box, and each optical fiber composite overhead ground wire 23 is interconnected via the junction box, while
Optical fiber 3 in optical fiber composite overhead ground wire 23
a. A connection structure may be considered in which the spacer 21 and the metal pipe 20 are mutually connected to the adjacent ones in the connection box, but in this case, the metal pipe 20
A retaining structure and metal pipe 20 to the connection box
It was necessary to develop a watertight structure in the portion where the water is drawn into the junction box.

In view of the above-mentioned circumstances, this invention provides a new retaining structure for retaining an optical fiber composite overhead ground wire, which is made by twisting a plurality of metal wires on the outside of a metal pipe housing an optical fiber and a rod-shaped spacer, to a junction box. It is intended to.

[Means for solving problems]

This invention includes a main body attached to a junction box by penetrating a part thereof, a gripping member attached to the main body and grasping an end of an optical fiber composite overhead ground wire,
a through hole formed in the main body that guides the metal pipe drawn out from the end of the optical fiber composite overhead ground wire into the connection box; and an introduction part of the main body that draws the metal pipe into the through hole. a watertight retaining member that is removably attached and maintains watertightness between the metal pipe and the through hole; a fixing member externally fitted on the metal pipe pulled out from the through hole; and a fixing member that is removably attached to the main body. The present invention is characterized by comprising a pressing member that is attached to the metal pipe and presses the fixing member to fix the metal pipe.

〔Example〕

Embodiments of this invention will be described below with reference to the drawings. Figures 5A to 5C are diagrams showing the configuration of an embodiment of this invention, and Figure 5A is a diagram showing A in Figure 5B.
-A-line view, Figure 5B is a partially cutaway side view, Figure 5
Figure C is a view taken along line B--B in Figure 5B. In addition, in FIG.
1 is connected to an adjacent spacer by a connecting fitting (not shown).

First, in FIG. 5B, 26 is a main body in which an insertion hole 26a through which the metal pipe 20 is inserted is formed in the center, and a flange portion 26b is formed along the outer circumferential surface at approximately the center in the longitudinal direction. A cylindrical fixing portion 26c (see FIG. 5A) is formed from the portion where the flange portion 26b is formed to the left in the drawing. An annular groove 2 is formed on one side of the flange portion 26b.
6d is formed, and an O-ring 27 is fitted into this annular groove 26d. In addition, the fixed part 26c
A male screw portion 26e is formed on the outer circumferential surface of.
The main body 26 has its fixed portion 26c connected to the connection box 2.
At the same time, a fixing nut 28 is screwed into the outer periphery of the fixing part 26c, thereby fixing it to the connection box 25. In this case, the opening 25 on the outer surface of the junction box 25
An O-ring 27 is pressed around the connection box 25 to provide watertight protection, and washers 29a and 29b are interposed between the inner surface of the connection box 25 and the fixing nut 28. The main body 26 fixed in this way includes connection bars 30a, 30a, 30b,
Each base end of 30b has hexagon socket head bolts 31, 31,
... are respectively attached by the connecting bar 3.
A pair of gripping members 32 are provided at each tip of 0a and 30a.
a32a are respectively attached by hexagon socket head bolts 33, 33, . On the other hand, the connecting bar 30
The tips of b and 30b are gripping members 32a and 32b.
are fitted into the mutually abutting portions of the two.
(See FIG. 5C) These pair of gripping members 32a,
Reference numeral 32b is used to compress and fix the end of the optical fiber composite overhead ground wire 23 shown by the two-dot chain line in the figure by being tightened with the tightening bolts 35, 35, . . . . Additionally, a pair of gripping members 32a, 32
Fiber optic composite overhead ground wire 2 fixed by b
The metal pipe 20 pulled out from the end of the main body 26 is inserted into the through hole 26a formed in the main body 26.
A cylindrical introduction portion 26f is formed in the portion of the main body 26 where the metal pipe 20 is drawn into the through hole 26a. The inner circumferential surface of the introducing portion 26f is formed such that the inner diameter gradually increases at the end edge thereof, and an O-ring 37 is fitted into this portion. Further, a male screw portion 26g is formed on the outer peripheral surface of the introduction portion 26f, into which a seal nut 38 is screwed. This seal nut 38 has a through hole 38a in the center through which the metal pipe 20 is inserted, and when it is screwed into the introduction part 26f, it presses the O ring 37 via the seal washer 39, thereby causing the external This prevents rainwater or the like from entering the gap between the through hole 26a and the metal pipe 20. On the other hand, the metal pipe 20 pulled out from the through hole 26a has a cylindrical fixing part 26c.
A fixing clamp 40 shown in FIG. 6 A, B, and C is fitted onto the metal pipe 20 pulled out from the through hole 26a. . This fixed clamp 40 is composed of a member having a substantially truncated conical shape, and has a hole 40a with an open top and bottom surface through which the metal pipe 20 is inserted, and a cutout groove 40b extending from the bottom surface to the vicinity of the top surface. Notch groove 4 extending from the top surface to the vicinity of the bottom surface
0c are formed alternately. Further, a slide clamp 41 shown in FIGS. 7A and 7B is fitted onto the fixed clamp 40. This slide clamp 41 is the outer peripheral wall 40b of the fixed clamp 40.
It is composed of a substantially cylindrical member having an inner circumferential wall 41a whose inner diameter gradually increases in contact with the inner circumferential wall 41a. on the other hand,
A female screw portion 26h is formed on the inner peripheral surface of the fixing portion 26c, into which a clamp screw 43 is screwed. Then, by screwing in this clamp screw 43, the end surface of the clamp screw 43 is aligned with the washer 4.
4, the slide clamp 41 is pressed to the right in the drawing, and the inner circumferential wall 41a of the slide clamp 41 compresses the outer circumferential wall 40d of the fixed clamp 40. As a result, the fixed clamp 40 is crushed, and the metal pipe 20 is clamped from the outer periphery. In this case, since the fixed clamp 40 is held between the main body 26 and the slide clamp 41, its movement is restricted, and as a result, the metal pipe 20 is fixed.

In the detention structure configured as described above, the O-rings 27 and 37 completely prevent rainwater from entering the inside of the connection box 25, and the metal pipe 20, which is the outer sheath of the spacer-type optical fiber cable, is securely fixed to the main body 26 by the action of the fixed clamp 40, slide clamp 41, and clamp screw 43.

[Effect of idea]

As explained above, according to this invention, a new tie-down method is developed for holding an optical fiber composite overhead ground wire, which is made by twisting a plurality of metal wires on the outside of a metal pipe containing an optical fiber and a bar-shaped spacer, to a junction box. In addition, it is possible to securely hold the metal pipe in the junction box, ensure watertight protection at the part where the metal pipe is drawn into the junction box, and furthermore, it is possible to securely hold the metal pipe in the junction box. This has the advantage that the removal and installation work of each part can be easily performed. Furthermore, the pressing member that is screwed into the female thread provided on the main body is fitted onto a fixed member that can be deformed in the radial direction, and a tapered surface is provided between these members, so that the pressing member can be screwed. In particular, the propulsive force of the pressing member can be converted into a radially inward force, and the fixing member can be uniformly deformed radially inward to firmly hold the metal pipe. Since the member is deformable in the radial direction, there is an effect that flexibility is provided for the outer diameter of the metal pipe.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view showing the configuration of a conventional optical fiber composite overhead ground wire, Figure 2 is an enlarged cross-sectional view of the optical fiber cable in Figure 1, and Figure 3 is a cross-sectional view of a conventional optical fiber composite overhead ground wire. FIG. 4 is a cross-sectional view showing the structure of the optical fiber composite overhead ground wire to which this invention is applied;
Figures 5A, 5B, and 5C are views showing the configuration of an embodiment of this invention. Figure 5A is a view taken along line A-A of Figure 5B, and Figure 5B is a partially cutaway side view. 5C is a view taken along line BB in FIG. 5B, and FIGS. 6B is a plan view, FIG. 6B is a sectional view taken along the line D-D in FIG. 6A, FIG. 6C is a bottom view, and FIGS. 7A and 7B are side cross sections of the slide clamp 41 shown in FIG. 5B. FIG. 2 is a diagram and a plan view. 3a... Optical fiber, 5a... Bare wire, 20...
Metal pipe, 21... Rod-shaped spacer, 23... Optical fiber composite overhead ground wire, 25... Junction box, 26...
...Main body, 26a...Through hole, 26f...Introduction part,
32a, 32b...Gripping member, 37...O ring (watertight member), 40...Fixing clamp (fixing member), 41...Slide clamp, 43...Clamp screw (pressing member).

Claims (1)

[Scope of utility model registration request] A plurality of grooves 21a are formed on the outer peripheral surface along its longitudinal direction.
a rod-shaped spacer 21 in which a plurality of optical fibers 3a are respectively arranged in the plurality of grooves 21a.
In the retaining structure for retaining an optical fiber composite overhead ground wire 23 made of a plurality of metal wires 5a twisted together on the outside of a metal pipe 20 containing a a main body 26 attached to the main body 26; gripping members 32a and 32b attached to the main body 26 and gripping the ends of the optical fiber composite overhead ground wire 23; The metal pipe 20 pulled out from the end of the wire 23
into the connection box 25, and the metal pipe 20 of the main body 26 into the through hole 26a.
The metal pipe 20 and the through hole 26
a watertight maintenance member 37 that maintains watertightness between the
A fixing member 40 is fitted onto the metal pipe 20 pulled out from the through-hole 26a, and a female screw portion 26h, which is fitted onto the fixing member 40 and provided in the axial direction of the main body 26, is screwed into the fixing member 40. The fixing member 40 has a hole 40a into which the metal pipe 20 is inserted, and the fixing member 40 has a hole 40a into which the metal pipe 20 is inserted, and the hole 40a is deformed in the radial direction. Notch grooves 40b are formed at multiple locations in the circumferential direction to allow
A tapered surface is formed on the inner periphery of the pressing member 43 and the outer periphery of the fixing member 40 for converting the displacement of the pressing member 43 due to screwing into the radially inward displacement of the fixing member 40. Optical fiber composite overhead ground wire retaining structure.