JP3118796B2 - Tensile resistant cable - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tension-resistant cable used for an uninterruptible bypass method of overhead distribution lines, for example.

[0002]

2. Description of the Related Art A bypass cable used in a conventional uninterruptible bypass method is:
In order to prevent tension from being applied to the cable, a messenger wire is lashed to the cable, or a structure in which the messenger wire is embedded in a protective coating layer of the cable is used. However, the bypass cable having such a structure is not flexible and has poor workability, and is not preferable as the bypass cable.

For this reason, a messenger wire is often installed in advance, and a flexible cable is hung on the messenger wire using a cable hanger or the like. However, in this case, erection of the messenger wire and suspension using a cable hanger are indispensable, and therefore, there is a problem that the working time of the uninterruptible construction is prolonged.

[0004]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems and eliminates the necessity of erection of a messenger wire as in the prior art, thereby making it possible to greatly reduce the time required for uninterrupted work. A feature of the present invention is that the shielding layer provided on the outside of the cable core is constituted by a braided braid of a non-metallic wire such as a metal wire and a cotton thread and a high-tensile fiber, and the above-mentioned metal wire and the non-metallic wire are provided. Is the opposite direction, and the high-tensile fiber is braided in both directions.

[0005]

In the tension-resistant cable of the present invention having the above-described structure, the high-tensile fibers interwoven in the shielding layer share the tension applied to the cable, so that the messenger wire does not need to be installed. However, in such a state where the high-tensile fibers share the tension, a large stress is applied to the shielding layer as compared with a cable having a general shielding layer. Therefore, in a structure in which a metal wire and a high-tensile fiber are simply interwoven and braided,
There is a high possibility that the metal wires rub against each other when the cable is bent due to the intersection of the metal wires, or the metal wires are broken due to the action of shear stress at the time of crushing. So, metal wire,
Along with the high-tensile fiber, the non-metallic wire such as cotton thread with good slip is interwoven and braided so that the high-tensile fiber is in both directions so that the metal line and the non-metallic wire are in opposite directions. As a result, the possibility of the metal wire breaking can be significantly reduced. Further, since the high-tensile fibers are braided in both directions, the tension can be shared in a balanced direction.

[0006] By impregnating the resin with the high-tension fiber, the high-tension fiber becomes less slippery. In this case, if the impregnated resin is of a hardening type, the flexibility of the cable is deteriorated.
Use a non-curing type. Further, by applying the protective coating layer so as to be hardened between the braids by solid extrusion, the high-tensile fiber becomes less and less slippery, and can efficiently share the tension.

[0007]

FIG. 1A is a cross-sectional view of a tension-resistant cable according to the present invention, and FIG. 1B is a developed view of a shielding layer of FIG. 1A. In the drawings, reference numeral 1 denotes a cable core, which is provided with an insulating layer 3 of vinyl chloride, polyethylene, cross-linked polyethylene or the like on a conductor 2, and further has an external semiconductive layer 4 thereon. Outside the cable core 1, a shielding layer 5 and a protective coating layer 6 of vinyl chloride, polyethylene, rubber or the like are provided. In order to prevent the shielding layer 5 from getting into the external semiconductive layer 4, a seating tape such as a semiconductive tape may be applied between them.

[0008] As shown in FIG.
The metal wire 11, the non-metal wire 12, and the high-strength fiber 13 are composed of a cross-woven braid.
The braiding direction of No. 2 is the opposite direction, and the high-tensile fibers 13 are braided in both directions. As the metal wire 11, a material for shielding a general cable such as a tin-plated soft copper wire, a soft copper wire, a soft aluminum wire can be used, and the non-metal wire 12 is a thread such as a wire, which is considered to be appropriate in design. May be appropriately selected. The high-tensile fiber is obtained by twisting a bundle of polyaramid fibers or a bundle of non-curable polyaramid fibers such as an ester-type polyurethane resin impregnated with a resin having a Vicat softening point of 150 ° C or higher. Are used. The twist grooves formed by the twisting form irregularities on the surface of the high-tensile fiber, and as shown in FIG. 1 (c), the number of protrusions is 10 or more per 1 cm ^{2 of the} outer surface of the high-tensile fiber, so that the protective coating is formed. The frictional resistance with the layer is dramatically increased, and the high tension effect can be further enhanced.

A protective coating layer 6 is provided on the outer periphery of the shielding layer 5, and this protective coating layer 6 is formed by solid extrusion of rubber and plastic so as to be tightly inserted between braids as shown in FIG. .

[0010]

As described above, according to the tension-resistant cable of the present invention, since the high-tensile fibers interwoven in the shielding layer share the tension applied to the cable, the conventional messenger wire installation work is unnecessary. The work time of uninterrupted work can be greatly reduced. Also, since the metal wire and the non-metal wire are braided in opposite directions, even in a state where tension is applied to the high-tensile fibers woven in the shielding layer, rubbing of the metal wires is eliminated, and the metal wire is hardly broken. Become.

[Brief description of the drawings]

FIG. 1A is a cross-sectional view of the tensile strength cable of the present invention, FIG. 1B is a developed view of the shielding layer of FIG. 1A, FIG.
(C) is a state diagram of twisting of high-tensile fibers.

FIG. 2 is an enlarged view of a contact cross section of a shielding layer and a protective coating layer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cable core 5 Shielding layer 6 Protective coating layer 11 Metal wire 12 Non-metal wire 13 High-tensile fiber

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-161610 (JP, A) JP-A 55-21544 (JP, U) JP-A-6-45215 (JP, U) (58) Investigation Field (Int.Cl. ⁷ , DB name) H01B 7/18 H01B 9/02

Claims (3)

(57) [Claims] 1. A shielding layer provided on the outside of a cable core is made of a cross-woven braid of a non-metallic wire such as a metal wire and a cotton thread and a high-tensile fiber, and the braiding directions of the metal wire and the non-metallic wire are opposite to each other. And a high-strength fiber is braided in both directions. 2. A tension-resistant cable according to claim 1, wherein the high-tensile fibers are formed by twisting a bundle of polyaramid fibers impregnated with a resin. 3. The tension-resistant cable according to claim 1, wherein the protective coating layer provided on the shielding layer is formed by solid extrusion of rubber or plastic, and is hardly inserted between the braids.