JPS5823136Y2 - connection cable - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a plastic insulated communication cable with a watertight dam that prevents water from running inside the communication cable.

In recent years, plastic has increasingly been used as an insulator for communication cables instead of paper.

Plastic insulated communication cables have the same or better properties than paper insulated cables, but if water gets into the cable, conventional paper insulated cables The insulator swells,
Although this method acted as a dam against flooding and was able to suppress the flooding locally to some extent, plastic insulated cables do not allow water to run inside the cable due to the water running properties of the plastic and the large porosity of the communication cable. This has the disadvantage that the flooded areas are rapidly expanding.

As a measure to prevent this drawback, cables have already been developed in which the inside of the cable is filled with a water running prevention compound.

However, while a cable filled with a water running prevention compound inside the cable can completely prevent water from running inside the cable, it is difficult to prevent water from running between the presser tape and the plastic sheath. It had drawbacks.

In order to prevent water from running between the presser tape and the plastic sheath, it has been proposed that the presser tape is filled with a compound to prevent water from running, similar to the inside of the cable.
In this case, the compound filled in the tape may fall off from the tape during cable manufacture, making it impossible to sufficiently exhibit the anti-water running effect, which has the drawback of making it difficult to manage and manufacture the presser-wound tape.

In addition, there is also the drawback that the manufacturing cost increases because the process of filling the presser tape with the compound for preventing water running is increased.

Furthermore, the water running prevention effect was limited by the pressure tape itself, and it could not be said that the water running preventing compound could fully demonstrate its effect.

The present invention was developed with the aim of providing a communication cable that can prevent water from running between the presser tape and the plastic sheath, which is a disadvantage. Alternatively, it can be made of twisted cable cores, a watertight dam filled with a water-travel prevention compound provided in the cable core, a presser tape provided around the outer periphery of the cable core, and a plastic sheath provided around the outer periphery. In the communication cable consisting of
The communication cable is characterized in that the presser tape itself is made of a material that swells upon absorption of moisture.

Next, an embodiment of the cable of the present invention will be described with reference to the accompanying drawings.

Reference numeral 1 is an insulated wire core in which a conductor made of copper is extruded and coated with a plastic insulator such as polyethylene, and the required number of wires are assembled or twisted together.

Reference numeral 2 denotes a water running prevention compound filled in the gaps between the insulated wire cores, which acts as a water dam to stop water from entering if water enters.

Even if this watertight dam is installed along the entire length of the cable,
Alternatively, they may be provided at appropriate intervals.

Reference numeral 3 denotes a holding tape, which not only maintains the shape of the assembled or twisted insulated wire cores, but also acts as a dam to prevent water from running along the holding tape 3 when water enters. be.

Therefore, the material used for the presser tape 3 is a fiber tape such as carboxymethyl cellulose tape, which itself swells by absorbing water, or a water-soluble plastic tape such as polyvinyl alcohol tape.

This presser tape 3 allows water to seep into the cable.

When this happens, it absorbs water and swells, acting as a dam to stop flooding.

Reference numeral 4 denotes a plastic sheath made of vinyl chloride or the like which is extruded and coated around the outer periphery of the presser tape 3.

In the cable of the present invention constructed as described above, water is prevented from running on the inside of the presser-wrapped tape by a water-running prevention compound, and between the presser-wrap tape and the plastic sheath, the presser-wrapped tape itself is used to remove water that has soaked in water. The plastic insulated communication cable absorbs water, swells, acts as a dam, and prevents water running, thus making it possible to provide a plastic insulated communication cable that has a complete water running prevention effect.

Furthermore, since the presser tape itself is made of a material that absorbs moisture and swells, it is easy to handle and easy to manufacture into cables, so it has great practical value.

[Brief explanation of drawings]

The attached drawing is an explanatory cross-sectional view showing one embodiment of the cable of the present invention. 1: Niblast insulated wire core, 2: Compound for preventing running, 3: Holder winding tape, 4 Niblast stick sheath.

Claims (1)

[Scope of utility model registration request] A cable core in which the required number of plastic insulated wire cores are assembled or twisted together, a watertight dam filled with a water running prevention compound provided in the cable core, a presser wrapping tape provided around the outer periphery of the cable core, and further the outer periphery of the cable core. 1. A communication cable comprising a plastic sheath provided on a plastic sheath, wherein the presser tape is made of a material that swells upon absorbing moisture.