Protective tube for communication cable and communication wire

Abstract

The invention aims to provide a protection pipe for communication cables and communication wires, which is easily bent to a specified bending diameter with a small force, but is hard to bend below the specified diameter with larger force so as to improve an effect of bending prevention. The invention comprises sheaths (13, 13A) consisting of two or more synthetic resin layers, and a protection pipe for communication wires, which protects the communication cables (10, 10A) of the communication wires (11, 11A) in a loose state or is inserted into the communication wires. The hardest resin layers (13a, 13aA) of the sheaths (13, 13A) are provided with ring-cutting shaped or spiral shaped annular grooves (4) or cuts (14A) made continuously in the longitudinal direction to reach the inside diameter surface; the outermost layers of the sheaths (13, 13A) are made of protection layers (13b, 13bA) formed by resin which is softer than the hard resin layers (13a, 13aA); when the communication wires (11, 11A) are bent, adjacent edge parts (14a, 14aA) of the annular grooves (14) or the cuts (14A) are contacted with each other to prevent the communication wires from being bent below the specified diameter.

Description

technical field [0001] The present invention relates to a communication cable which protects communication wires such as optical fibers and layered twisted wires with a synthetic resin sheath in a loose state or in a tight state, and particularly relates to the protection of plug-in communication cables and communication wires used in indoor wiring. Tube. Background technique [0002] Communication cables are used for transmission and control of various information in vehicles, communication devices, and indoors. As the communication cable, an optical fiber for optical communication or a wire for electrical communication is used, and the outer periphery of the single-core or multi-core wire is directly or loosely covered with a sheath. In addition, as a cable form in which a communication line is covered with a cover, a protective tube serving as a cover of the communication line is laid in advance, and then the communication line is inserted into the protective tube as nec...

AI Technical Summary

Problems solved by technology

Therefore, when bending the communication cable, there is a danger of being bent below the specified bending diameter due to inertia, etc.

In addition, if the adjacent protrusions are in contact with each other, the covering layer is deformed, and a sufficient effect of preventing bending cannot be obtained.

Therefore, in order to reduce the deformation of the convex part, if the anti-bend covering layer 3 with concavities and convexities is made of hard resin, when the communication cable is repeatedly bent, it is easy to cause unsuitable situations such as whitening of the concave part and deepening of cracks.

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