JPH0452687B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement in a method for pulling down an optical fiber composite overhead ground wire to obtain extra length necessary for connection.

[Conventional technology and problems] When connecting optical fiber composite overhead ground wires,
A commonly adopted method is to tie the ground wire to the steel tower using a retaining clamp, pull down the optical fiber along with the remaining length of the wire, guide it to a junction box installed in the middle of the tower, and connect the optical fiber within the junction box. ing.

Conventionally, in order to take out the extra length of the electric wire, for example, when the electric wire is extended to the lowered steel tower, the electric wire is temporarily fixed to the lowered steel tower, and the length of the extended electric wire is equivalent to the above-mentioned extra length. A worker leans out to the position and attaches the come-along and wire, then releases the fixation on the wire delivery side, takes the wire to the tower side, and lowers the excess length via a metal wheel, or dangerously steps onto the wire. In order to avoid this work, the wires were temporarily fastened to the steel tower, then the wires were loosened to near the ground and the come-alongs were attached to them.

However, the above-mentioned work for the worker to step onto the ground line is extremely dangerous, and if the pull length becomes long, the work becomes extremely difficult. If this happens, there is even a risk of damaging the internal optical fiber. Furthermore, the method of letting the wires hang loose on the ground requires conditions such as good terrain and the absence of obstacles, and is not a method that can be implemented everywhere.

[Object of the Invention] The present invention has been made in view of the above-mentioned circumstances, and eliminates the drawbacks of the above-mentioned prior art, and eliminates the dangerous riding on the electric wire and the loosening of the electric wire. It is an object of the present invention to provide a method for lowering the excess length of an electric wire by which the excess length of the electric wire can be easily taken in, and a metal wheel used for the method.

[Summary of the Invention] That is, the gist of the present invention is to suspend a metal wheel having a winding groove capable of wrapping the extra length of the electric wire from a steel tower to be lowered, and to extend the electric wire through the metal wheel. After the electric wire is tied to the steel tower, there is a method for unwinding the wrapped electric wire and pulling down the excess length on the metal wheel, and a method in which the above-mentioned extra length winding groove is formed on the metal wheel. It is possible to safely and easily take out the extra length of the electric wire by simply winding and extending the electric wire.

[Example] This will be explained below based on examples.

FIG. 1 is a front view showing an embodiment of a metal wheel 10 used in carrying out the present invention, in which 1 is a rotating body rotatably attached to a frame 3, and 2 is an outer circumferential surface of the rotating body 1. a winding groove formed in the winding groove 2;
is constructed so that the electric wire can be wound in multiple turns in a spiral shape.

In the present invention, the metal wheel 10 configured as described above is suspended from a steel tower to which the electric wire is to be lowered, and as shown in FIG. The wire is wound around the ten winding grooves 2 and stretched. Therefore, the length of the winding groove 2 in this case is configured to have a length commensurate with the length of the wire to be pulled down. Now, let this pulling length be L, and the rotating body 1 of the metal wheel 10
When the radius of the spiral circle formed by the groove surface is r, and the number of times the groove is wound is n, there is a relationship L=2πr·n, so this L can be selected to be the above-mentioned pull-down length.

Now, consider an actual railway line that requires the above-mentioned extra length of drawdown of 15 m. In this case, the diameter of the groove surface of the rotating body 1 is
If 2r=1m is selected, it can be seen from the above relational expression that n should be set to approximately 5 times. Of course, this value changes depending on the length of the pull, so
It is desirable to have a structure in which unit groove structures can be connected as appropriate, and the number of windings can be increased or decreased as necessary. FIG. 2 is an explanatory diagram showing an embodiment of the rotating body 1 suitable for increasing and decreasing the number of grooves,
A plurality of rollers 4 are arranged in the winding groove,
By increasing or decreasing the number or diameter of these rollers 4 or adjusting the depth of the mounting position, the length of the electric wire wound around the groove can be easily adjusted.

The gold wheel according to the present invention configured as described above,
In practical use, the metal wheels 10 and 10 are arranged in series in the wire running direction as shown in Figure 4, the ground wire 20 is wrapped around both wheels as shown in the figure, and the wire is stretched. The ground wire 20 may be tied to the steel tower and cut at the intermediate point P, and the ground wire 20 wound around the metal wheels 10, 10 may be unwound and suspended in the direction of the middle part of the steel tower. By doing this, the left and right spans can be lowered at the same time. In addition, for securing the ground wire 20 to the steel tower, it is not only possible to use a temporary restraining device as in the case of the conventional method, but also a method for permanently securing the ground wire 20 and connecting the jumper wire to the tower. It can be fastened directly to a fastening clamp, etc.

[Effects of the Invention] As described above, according to the pulling down method according to the present invention, since the extra length of the wire is held in the groove of the metal wheel and the wire is extended, there is no need to attach clamps and wires necessary for taking off the extra length. Therefore, there is no need for the worker to stand on top of the wire or unnecessarily loosen the wire and pull it down, unlike in the conventional case, which not only greatly improves safety, but also makes work easier. It is possible to achieve efficient reduction by simplifying and omitting the above, and as the adoption of optical fiber composite overhead ground wires is gaining momentum, this timely proposal has great industrial significance.

[Brief explanation of the drawing]

FIG. 1 is a front view showing an embodiment of the metal wheel according to the present invention, FIG. 2 is an explanatory view showing an example of the structure of the rotating body of the metal wheel according to the present invention, and FIG. FIG. 4 is an explanatory diagram showing one embodiment of the present invention. 1... Rotating body, 2... Winding groove, 3... Frame body, 1
0... Gold car, 20... Optical fiber composite overhead ground wire.

Claims (1)

[Scope of Claims] 1. Two metal wheels each having a winding groove capable of wrapping the extra length of the electric wire around the outer periphery of a rotating body are suspended from a steel tower in which the extra length of the optical fiber composite overhead ground wire is to be lowered. ,
After winding the wire continuously around the two metal wheels and extending the wire, the wire is tied to the steel tower, the wire is cut in the middle between the two metal wheels, and then the extra length of the wire wrapped around the metal wheel is cut off. A method for lowering the extra length of an optical fiber composite overhead ground wire by unwinding and lowering it. 2. A metal wheel in which a rotating body is supported by a frame body, and a plurality of grooves are formed around the rotating body so that the extra length of the electric wire can be wound around it.