JPS61166502A - Connection box for optical fiber composite overhead earth wire - Google Patents

Abstract

PURPOSE:To reduce the load applied to an optical fiber cable by rotating a bobbin to wind up the optical fiber cable when a tensile force acts upon the optical fiber cable and rotating the bobbin by the elasticity of a spring to wind up the optical fiber cable when a compressive force acts upon it. CONSTITUTION:If a tensile force is generated in an optical fiber cable 22 in the layed state of an optical fiber composite overhead earth wire 20, a bobbin 6 is rotated by this tensile force to wind up the optical fiber cable 22. If a compressive force acts upon the optical fiber cable 22, the bobbin 6 is rotated by the elasticity of a spring 9 to wind up the optical fiber cable 22; and the bobbin 6 is stopped when the tension of the optical fiber cable 22 and the elasticity of the spring 9 are balanced, thereby preventing an excessive tension from being applied to the optical fiber cable 22.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a junction box used for connecting optical fibers of an optical fiber composite overhead ground wire.

[Conventional technology and its problems]

When installing an optical fiber composite overhead ground wire in which an optical fiber cable is inserted movably in the axial direction of the pipe inside a pipe made of aluminum or the like, and multiple overhead ground wires are placed along the outside of the pipe, cable extension is required. An optical fiber composite overhead ground wire is drawn to the connection point using a wire or the like, and the optical fibers are connected to each other in a connection box placed at the connection point.

By the way, in the optical fiber composite overhead ground wire, the optical fiber cable is loosely inserted inside the pipe, and the tension during installation does not act directly on the optical fiber cable, so the tension of the optical fiber cable is set. It is impossible to hold and install the value.

Conventionally, the optical fiber is directly fixed to the face plate of the junction box, so either compressive force or tensile force acts on the optical fiber, and the above load applied to the optical fiber can cause the optical fiber to break and be damaged. There is the inconvenience of doing something like that.

[Problem that the invention seeks to solve]

The technical object of the present invention is to eliminate the above-mentioned disadvantages, reduce the load on the optical fiber cable, and prevent damage to the cable.

[Means for solving problems]

In order to solve the above problems, the present invention rotatably provides a cable winding bobbin inside a box having a cable insertion hole, and provides a spring for applying a rotational force in the cable winding direction to the seventh bobbin. The flange of the bobbin is provided with at least two holes for taking out the cable end.

[For production]

As described above, by applying a rotational force in the cable winding direction to the cable winding bobbin, the ends of the pair of optical fiber composite overhead ground wires to be connected are fixed in the cable insertion hole, and only the optical fiber cable is connected. is introduced into the box body, wound around the outside of the bobbin from the same direction, the tip of the optical fiber cable is guided outside through the outlet hole of the flanone, and the original fiber of the optical fiber cable is connected to the other optical fiber. When a tensile force is applied to the above optical fiber cable, the bobbin rotates and the optical fiber cable is unwound, and when a compressive force is applied, the bobbin rotates due to the elasticity of the suge ring and the optical fiber cable is unwound. The load on the optical fiber cable can be reduced.

〔Example〕

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

As shown in FIGS. 1 and 2, one side of one end plate 2 of a pair of mutually opposing end plates 2.2 of the box 1;
Cable insertion holes 3 are formed in the other side of the other end plate 2, respectively.

Also, inside the box body 1, a guide plate 4 is provided parallel to the end plate 2.
The guide hole 5 provided in the guide plate 4 is arranged on the same axis as the cable insertion hole 3 facing thereto.

Furthermore, a cable winding bobbin 6 is arranged inside the box 1, and a shaft 7 provided at the lower end of the bobbin 6 is rotatably supported by a bottom plate 8 of the box 1. A spiral spring 9 is fitted on the outside of the shaft 7, and the elasticity of the spring 9 rotates the bobbin 6 in multiple directions for winding the cable.

Two spiral grooves 11.11 are provided on the outer peripheral surface of the cable winding body 10 of the bobbin 6. Further, in the flanone 12 above the bobbin 6, a pair of cable outlet holes 13, 13 are formed continuously to the ends of the spiral groove 11.

The junction box shown in the embodiment has the above-mentioned configuration. This junction box is installed at the connection point of the optical fiber composite overhead ground wire, and connects the ends of a pair of optical fiber composite overhead ground wires that are laid to the position of the connection point. is fixed to the end of the cable insertion hole 3, and only the optical fiber cable is introduced into the box 1 through the cable insertion hole 3 and connected to the other optical fiber cable.

Here, as shown in FIGS. 4 and 5, the optical fiber composite overhead ground wire 20 is a pipe 21 made of aluminum or the like.
An optical fiber cable 22, which is a bundle of a plurality of optical fibers, is inserted inside the pipe 21, and an overhead ground wire 23 such as an aluminum-coated steel wire is run along the outside of the pipe 21.

The end of the optical fiber composite overhead ground wire as described above is attached to the box body 1 via a fixture. Any fixture can be used as the fixture.The fixtures shown in the examples are:
As shown in FIGS. 4 and 5, it consists of a sleeve 30, a collar 31 disposed at the inner end of the sleeve 30, and a cap nut 32 for preventing the collar 31 from being removed.

The tip of the sleeve 30 has a slit 33 along the axial direction.
A pair of half bodies 34 and 34 are provided by forming the sleeve 30, and a pair of fastening pieces 35 are formed on both sides of the distal end of the half body 34. Also, a screw is provided on the outer peripheral surface of the rear end of the sleeve 30. 36 is formed, and the cap nut 32 can be screwed into this screw 36.

Now, the sleeve 30 is attached to the cable insertion hole 3, the collar 31 previously inserted inside the sleeve 30 is prevented from being removed by screwing in the cap nut 32, and the inside of the sleeve 30 is filled with a waterproof filler 37. By inserting the end of the optical fiber composite overhead ground wire 20 into the inside of the sleeve 30 and tightening the pair of opposing fastening pieces 35 with bolt donuts 38, the pair of half bodies 34 and 34 are connected to the overhead ground line 23
The ends of the can be clamped.

Installation as above should be done by connecting a pair of optical fiber composite overhead ground? 1J20 into each cable insertion hole 3 of box 1, and insert only the optical fiber cable 22 into box 1.
The tip of the optical fiber cable 22 is wound around the outer circumference of the bobbin 6 and inserted into the take-out hole 13 of the flange 12, and the optical fiber cable 22 is inserted into the guide hole 5 of the guide plate 4. By connecting the optical fibers 22' of the fiber cable 22 to each other, the connection of the optical fiber composite overhead ground wire can be completed.

FIG. 3 shows the connected state of the optical fiber 22', and 24 indicates a connecting portion.

When winding the optical fiber cable 22 around the outside of the bobbin 6, the optical fiber cable 22 is wound around the outside of the bobbin 6 with the bobbin 6 slightly rotated in the opposite direction to the cable winding direction.

When the optical fiber composite overhead ground wire 20 is installed as described above, if tensile stress occurs in the optical fiber cable 22, the bobbin 6 rotates due to the tensile force, and the optical fiber cable 22 is rewound. When a compressive force is applied, the grain pin 6 rotates due to the elasticity of the sedge ring 9 to wind up the optical fiber cable 22, and when the tension of the optical fiber cable 22 and the elasticity of the spring 9 are balanced, the bobbin 6 is rotated. is stopped and the fiber optic cable 22
This can prevent excessive tension from being applied.

〔effect〕

As described above, in this invention, the optical fiber cables of a pair of optical fiber composite overhead ground wires to be connected are wound in the same direction on the outside of a bobbin which is given a rotational force in the cable winding direction by the elasticity of a spring. , the tip of the optical fiber cable was taken out from the take-out hole formed in the flange of the bobbin, and the optical fibers were interconnected.
Optical fiber: Depending on the direction of the load acting on the fiber cable, the bobbin rotates to wind or unwind the optical fiber cable. Therefore, the tension applied to the optical fiber cable can be reduced, and damage to the optical fiber cable can be effectively prevented.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional bottom view of the junction box according to the present invention, Fig. 2 is an enlarged sectional view of the bobbin mounting portion of the above, Fig. 3 is a plan view of the bobbin of the above, and Fig. 4 is an optical fiber composite aerial FIG. 5 is a cross-sectional view showing the fixing part of the ground wire, and FIG. 5 is a vertical front view of FIG. 4. 1...Box body, 3...Cable insertion hole, 6...Bobbin. 9... Spring, 12... Flange, 13...
Cable exit hole

Claims (1)

[Claims] A cable winding bobbin is rotatably provided inside a box body with a cable insertion hole, a spring is provided on the bobbin to apply rotational force in the cable winding direction, and the cable end is taken out at the flange of the bobbin. A junction box for an optical fiber composite overhead ground wire that has at least two or more holes.