JP2008249917A - Distribution line cable disposed between columns and method of retaining cable - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem that the conventional method by which a messenger wire is preliminarily disposed on which an optical cable is supported by using cable hangers is very inconvenient and a problem arising in the work of the conventional method by which the messenger wire is disposed, and to provide, after elaboration to find a means for low cost, a new optical cable wire with messenger wire which eliminates the existing stereotype that the conventional messenger wire and the cable must be coated by a common plastic material. <P>SOLUTION: The distribution line cable disposed between columns is characterized in that a high tensile strength wire composing the messenger wire and a steel pipe containing the optical fiber have the same diameter, and at least one or two steel pipes containing the optical fiber stay in surrounding twisted structure without neighboring other steel wires. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a messenger wire containing an optical fiber cable wired between distribution poles, a hanger-free cable, and a cable retaining method.

  In order to install cables between distribution poles, the cables are conventionally routed along the messenger wires previously installed between the distribution poles, and the cables are hung on the messenger wires using hangers called hangers, One-way spiral coil is extrapolated to a messenger wire previously installed between distribution poles, a cable is inserted inside the coil, and the cables are bundled. The former is troublesome at a high place, and the latter is troublesome to insert a cable, as shown in, for example, Japanese Patent Publication No. 52-4033.

  Japanese Patent Laid-Open No. 2005-168284 using an alternate left and right spiral is known as an improvement plan. However, the extension of the left and right alternating spiral coils and the work of installing the messenger wires and cables separately are high work between the distribution poles, and lightning strikes and strong winds cause disconnections in the lines and optical communication failures. We are concerned about such problems.

  On the other hand, there is a self-supporting cable in which a messenger wire and an optical fiber cable are connected by a common plastic sheath neck. For example, see Japanese Patent Application Laid-Open No. 10-133301. When such a cable is subjected to a crosswind from the side, lift occurs and the cable is susceptible to low-frequency vibration dancing, so the optical fiber and distribution cable stored in the cable core are likely to deteriorate. There is a problem.

Japanese Patent Publication No.52-4033 JP 2005-168284 A Japanese Patent Laid-Open No. 10-133301

An object of the present invention is to provide an optical cable installed between distribution poles that does not cause such a problem.
That is, the power distribution poles are provided at intervals of 30 m to 50 m, and optical cables installed here are not so large and heavy in weight.
Therefore, the conventional method of installing a conventional messenger wire in advance and supporting the optical cable with a cable hanger is very troublesome, and the method using a spiral coil does not require the work of attaching a large number of hangers like a hanger. Therefore, we studied earnestly on the low cost method.
In other words, a new optical cable that solves the problem of work when the conventional messenger wire is installed in advance and is free from the constraint of the existing concept that the conventional messenger wire and cable must be a common plastic coating. A messenger wire with a wire and a new cable support method.
According to the present invention, a messenger wire is installed in advance with a relatively simple structure, a hanger is not necessary, and the messenger wire in a desired cable may be retained at the location of the utility pole, so that the structure of the cable is It is simple, can be easily installed between utility poles, and can be safely installed at low cost.

In the present invention, the high tensile strength wire constituting the messenger wire and the steel pipe containing the optical fiber have the same diameter, and at least one or three of the steel pipe containing the optical fiber are not adjacent to each other. A cable for installing between distribution poles characterized in that it is present in a twisted structure (Claim 1), wherein there may be one steel pipe housing an optical fiber in the outer twisted structure, The center of the steel pipe according to claim 2 is used, when two steel pipes containing fibers are used and one steel wire is arranged via two high tensile strength wires, or three steel pipes containing optical fibers are used. The steel wire may be formed by alternately twisting a high tensile strength wire and a steel pipe containing an optical fiber around the steel wire. In this case, a cable containing the most optical fibers can be provided.
Further, the present invention is the cable for installing between distribution poles according to claim 1 or 2, wherein a proven stainless steel pipe is used as a steel pipe housing an optical fiber (Claim 3).
A distribution pole comprising the distribution pole installation cable according to any one of claims 1 to 3, wherein the cable is installed between the distribution poles, and the high-tensile wires in the cable are gathered together and secured by a retaining bracket. This is a method of retaining an intermediary cable (claim 4).

The cable for installing the utility pole of the present invention, in particular, a messenger wire is installed separately, and can be installed easily without using a spiral support, and the optical cable is inserted into the conduit, Without being affected by external weather conditions, it does not cause communication failures due to micro vibrations or problems due to salt damage,
In addition, the high strength wire in the center and the high strength wire in the wire layer from the outer periphery are gathered together at the retaining portion of the utility pole and retained as a messenger wire. There are effects such as less equipment and easier work in high places.
Furthermore, the steel pipe containing the optical fiber has the same diameter as the high-strength wire and is twisted in a balanced manner as a whole, and has an overall twisted wire structure. Therefore, the cable may be oriented in any direction.

FIG. 1 is a cross-sectional view showing a structural example of a cable for installing between distribution poles obtained by the present invention. A steel pipe in which a high tensile strength wire 1 is provided in the center portion and around the center portion and an optical fiber is accommodated. 2 and twisted alternately.
In addition, although not shown in figure, the steel pipe 2 which accommodated the optical fiber may be 1 line | wire, and 2 line | wires may be arranged through every 2 line | wire of the high tensile strength wire 1. FIG.
In the figure, the outer diameters of all the high tensile strength wires 1 and the steel pipes 2 containing the optical fibers are the same, and the nominal cross-sectional area and outer diameter are calculated from the tensile load. Even when the steel pipe is used, the overall design can be made by judging the stranded wire, that is, the design value of the messenger wire as an approximate value. For example, when the cross-sectional area is 22 mm ² , the diameter is 6.0 mm, when the cross-sectional area is 55 mm ² , the diameter is 9.6 mm, and when the cross-sectional area is 135 mm ² , the diameter is 15.0 mm. Usually, an outer diameter of about 6.0 mm to 15.0 mm is practical.

The material of the steel pipe 2 containing the optical fiber is normally used from the standpoint of strength of SUS, which has a proven track record, and corrosion prevention by the atmosphere, and the galvanized steel wire is inexpensive for the high tensile strength wire 1, used.
Of course, an aluminum-coated steel wire may be used. This is preferable because it is resistant to salt damage.
In FIG. 1, a high tensile strength wire 1 and a metal tube housing optical fiber 2 having the same diameter are alternately arranged around one high tensile strength wire, and six strands are twisted as a whole.
Although the high tensile strength wire 1 and the steel pipe 2 containing the optical fiber are alternately positioned and twisted together, as described above, the steel pipe 2 containing the optical fiber is required to be one strip or as required. Even two are acceptable. That is, it is preferable not to adjoin the steel pipe containing the optical fiber in view of strength retention and influence on the optical fiber.
In addition, although the steel pipe 2 which accommodated the optical fiber is one layer, when considering the number of optical fibers accommodated therein, this is sufficient, and it is not necessary to have two or more layers.

Although not shown, the outer peripheral steel wires and the steel pipes containing the optical fibers are biased in an assembled state, and the outer peripheral steel wires 3 and the steel pipes 3 containing the optical fibers are grouped into groups. In the case of twisting together, it seems that retaining at the power pole seems simple, but it is not preferable because the strength of the cable itself is not uniform in the circumferential direction. In short, it is preferable that the steel wire and the steel pipe containing the optical fiber are twisted in a well-balanced manner in terms of production and product.
The presence of the center high tensile strength line is effective in preventing microbending of the surrounding optical fiber.

  In the present invention, when an optical fiber is installed between distribution poles, it is retained using a high tensile strength wire in the cable structure, so that it can be easily installed without requiring a separate messenger wire, a hanger, or a lashing rod. .

It is sectional drawing of an example of the aerial cable of this invention.

Explanation of symbols

1 High tensile strength wire 2 Steel pipe containing optical fiber

Claims (4)

The high tensile strength wire constituting the messenger wire and the steel pipe containing the optical fiber have the same diameter, and at least one or three of the steel pipe containing the optical fiber are not adjacent to each other in the surrounding twisted configuration. A cable for installation between distribution poles, characterized by the existence.   The cable for installing distribution poles according to claim 1, wherein the cable is constructed by alternately arranging and twisting high tensile strength wires at the center and steel pipes containing optical fibers around them.   The cable for installing a utility pole according to claim 1 or 2, wherein a stainless steel pipe is used as the steel pipe containing the optical fiber.   A cable for laying between distribution poles according to any one of claims 1 to 3, wherein the cable for laying between distribution poles is laid between the distribution poles, and the high tension wires in the cable are gathered together and fastened with a fastening bracket. Retention method for erection cable.

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