JPS61163513A - Communication cable - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a stretchable communication cable.

[Conventional technology]

Communication cables include local cables, intercity cables, intra-office cables, submarine cables, and high-frequency cables. Particularly, for local cables and long-distance cables, conductors are tightly wrapped with insulating paper tape to insulate them from each other, and multiple cables are bundled together. Furthermore, for intra-office cables, submarine cables, high frequency cables, etc., conductive wires coated with insulating synthetic resin are used.

[Problem that the invention seeks to solve]

However, in such conventional examples, in order to reduce the cost of materials and for other reasons, it is necessary to use the thinnest communication wires possible, and it is also necessary to use communication wires that are buried underground or installed in the air. However, various external forces such as shock and tension may be applied to this cable, and if such external force is greater than the cutting stress of the communication cable that makes up the cable,
The front or part of the cable will be cut.

Therefore, in reality, very thin communication wires could not be used.

In particular, since the communication cables that make up telephone cables are thin, there is a limit to their tensile strength, and if tension close to the limit of cutting stress is constantly and repeatedly applied, the conductors that make up the cables will fatigue. However, there was a problem in that its durability was impaired. For example, there have been problems with utility poles tilting due to external forces, and conductors breaking when objects come into contact with them.

Also, if you move the phone indoors and use it,
There are problems with wires breaking when people's feet get caught in them, and phones falling.

Furthermore, the required length of the communication cable must be strictly ensured. However, in reality, the cable may be cut to a slightly shorter length than necessary due to a mistake during work, and in that case, the communication cable becomes unusable.

Means for Solving Problem c] The communication cable according to the present invention includes a large transmission line in which a conducting wire is wound around an elastic thread, and an insulating member that covers this transmission line and has a predetermined elasticity. 1. A communication cable characterized in that a plurality of unit cables are bundled together, and a synthetic resin material having elasticity is further coated and layered around the bundle of unit cables.

[Effect]

As the elastic thread expands and contracts, the coil body of the conducting wire wound around it also expands and contracts. Further, the insulating member covering the transmission line made of elastic thread and conductive wire expands and contracts as the transmission line expands and contracts. A unit cable having such an effect performs a similar expansion and contraction operation even when a plurality of unit cables are bundled together. In addition, the elastic synthetic resin material expands and contracts with the gentle movement of the bundle of unit cables, thereby increasing the tensile strength.

〔Example〕

Hereinafter, embodiments of the present invention shown in the drawings will be described.

The unit cable 1 shown in FIG.
It consists of

The elastic yarn 2 is an elastic strip made of fibers made by mixing diisocyanates and polyols and extruding the mixture from a spinning nozzle and hardening it, and has a diameter of 1 to 6 mm.

The conducting wire 3 is formed by rolling a copper wire having a diameter of 0.3 fins and forming it into a flat shape, and is wound around the elastic thread 2 at a rate of 500 turns/m.

In addition, when winding the guiding fI3 around the elastic thread 2,
The elastic thread 2 is stretched by about 3.5 times as shown in Fig. 4(a), and in that state, the conductive wire 3 is wound to increase the stretching capacity (
Figure 4(b)).

In this way, a transmission composed of the elastic thread 2 and the guiding fl13!
The unit cable 1 is constructed by covering the fIAa with a stretchable insulating member 4 (FIG. 4(c)). Note that 6 shown in FIG. 4(C) is a splint thread that temporarily suppresses the elongation of the transmission line a, and may be made of nylon, polyester, or other various thread materials that do not have substantial elasticity. . The splint 6 regulates the tension of the transmission line a when covering the insulating member 4, thereby improving workability. When the covering of the insulating member 4 is completed, the unit cable 1 is pulled, the splint 6 is cut, and the predetermined elasticity can be restored.

As shown in FIG. 2, four unit cables 1 are twisted together to form a star-shaped quad, and the periphery thereof is covered with an elastic synthetic resin material 5 to constitute a communication cable A.

In addition, the method of coating the synthetic resin material 5 on a bundle of unit cables 1 to 1 is as follows: unit cables 1 to 1 are bundled, put through an extruder, pulled out from a drawer opening, and arranged so as to surround the pullout opening. A molten synthetic resin material 5 is extruded from an extrusion nozzle to cover the bundle of unit cables 1 to 1.

Next, FIG. 3 is a sectional view showing another embodiment of the elastic thread 2 constituting the communication cable A according to the present invention.

In the figure, 2a is a core material made of polyurethane, and around this core material 2a, a synthetic resin material 2b having slightly less elasticity than the core material 2a is coated by extrusion molding. The double-structured elastic yarn 2 constructed in this way is made into a communication cable A through the same steps as in the previous embodiment. In this embodiment, the diameter of the core material 2a made of polyurethane can be kept small, and a predetermined diameter can be ensured by covering it with another relatively inexpensive synthetic resin material 2b.

In both of the above embodiments, the unit cable l is 4
It is bundled together and is especially configured as a telephone cable.

Further, in both of the above embodiments, the conducting wire 3 is an electric wire, but it is of course possible to change the design to an optical fiber.

〔Effect of the invention〕

As is clear from the above explanation, this communication cable can be used in the event that an external force in the form of shock or tension is applied to it in a direction that intersects with the axial direction or along the axial direction. However, it can be absorbed by its elongation, and therefore has the effect of preventing cutting due to such force.

Furthermore, even if the length is cut out to be somewhat shorter than the required length during wiring work, it can be stretched and used.

This communication cable is particularly useful as a cable for telephones that requires elasticity.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram showing a unit cable constituting the communication cable of the present invention, Fig. 2 is a sectional view showing the same communication cable, and Fig. 3 is a sectional view showing another embodiment of the elastic thread according to the invention. 4A to 4C are explanatory diagrams showing the manufacturing process of a unit cable. 1...Unit cable, 2...Elastic thread,
3... Conductor wire, 4... Insulating member, 5...
...Synthetic resin material.

Claims (2)

[Claims] (1) A plurality of unit cables each consisting of a transmission line in which a conductive wire is wound around an elastic thread and an insulating member that covers this transmission line and has a predetermined elasticity are bundled together. A communication cable characterized in that a bundle of unit cables is further coated with a stretchable synthetic resin material. (2) The elastic yarn has a core material made of a fiber made by mixing diisocyanates and polyols and extruding it from a spinning nozzle and hardening it, and a synthetic resin material that covers the core material to increase its tensile strength. The communication cable according to claim 1, which is a structure.