JP3605619B2 - Guidance lines for radio rebroadcasting - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a radio rebroadcasting guide line for transmitting to a radio rebroadcasting facility installed for emergency use such as a tunnel and for customer service.
[0002]
[Prior art]
Conventionally, as an induction line for radio rebroadcasting, a commercially available overhead distribution line electric wire (OW line) is used, and a few meters are provided on lining concrete such as a ceiling or a wall surface of a tunnel or the like. Since the insulator is supported and wired, if the insulation coating cracks due to vibration or aging, moisture will enter from it and the conductor will be corroded, eventually leading to corrosion of the conductor and breaking of the wire, and the electric wire will go to the roadway. The problem of sagging occurs.
[0003]
[Problems to be solved by the invention]
The present invention has been made in order to solve the problems described in the prior art, and aims to provide a guide line for radio rebroadcasting such as a radio rebroadcast that does not drop on a road even if a conductor is corroded and disconnected. is there.
[0004]
[Means for Solving the Problems]
The guide line for radio rebroadcasting of the present invention has a string-like member made of non-metallic fiber having corrosion resistance and flexibility and tensile strength at the center, so that no tension is applied to this member. It is characterized in that a plurality of conductors are twisted around it, and an insulator is further extruded and coated thereon.
[0005]
BEST MODE FOR CARRYING OUT THE INVENTION
One example of an embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, it is made of a non-metallic fiber having corrosion resistance such as aramid fiber and also having flexibility and tensile strength. A string-shaped member 1 is disposed at the center, and a plurality of conductors 2 such as hard copper wire and hard aluminum wire are twisted around the member 1 so that tension is not applied to the member 1, and an insulating material such as polyethylene is further placed thereon. Body 3 is extrusion coated.
[0006]
During normal use, no tension is applied to the string-like member 1 made of aramid fiber or the like, and the tensile strength does not decrease due to the mechanical tensile load of the member 1 in normal use.
[0007]
When the conductor 2 such as a hard copper wire is corroded and broken due to the ingress of moisture due to cracks in the insulator 3 or the like, the conductor 2 is cut and separated at the broken portion. A tensile load is applied to the member 1 to prevent the guide line according to the present invention from drooping on the roadway.
[0008]
【The invention's effect】
Since the present invention is configured as described above, it has the following effects.
{Circle around (1)} In a steady state, since a tensile load is not applied to a string-like member made of aramid fiber or the like, there is no decrease in tensile strength.
{Circle around (2)} When a conductor is disconnected, a tensile load is applied to a string-like member made of aramid fiber or the like, thereby preventing a guide line such as a rebroadcast from hanging down on a roadway.
{Circle over (3)} Since the conductor is twisted around a string-shaped member made of aramid fiber or the like, the conductor is flexible, and wiring work is easy.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an example of the embodiment.
DESCRIPTION OF SYMBOLS 1 String-like member made of aramid fiber 2 Conductor 3 Insulator

Claims (1)

A string-shaped member (1) made of aramid fiber is disposed at the center, and a plurality of conductors (2) are twisted around the member (1) so that tension is not applied to the member (1). (3) Extrusion coating for radio rebroadcasting, characterized by extrusion coating

Images