JP2008191209A - Loose-type optical fiber cord - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a loose-type optical fiber cord that can prevent hydrotaxis without using an aluminum tube. <P>SOLUTION: In the optical fiber cord which is composed of a coated optical fiber, a tension fiber layer covering the outer periphery of the coated optical fiber, and a jacket covering the outer periphery of this tension fiber layer; at least one water-absorbing yarn is installed in the tension fiber layer to constitute the loose-type optical fiber cord. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a loose type optical fiber cord.

    Since the conventional loose type optical fiber cord is used indoors, water resistance is considered unnecessary, so the optical fiber core, the tensile fiber layer covering the outer periphery of the optical fiber core, and the tensile fiber layer It is comprised with the outer covering which covers the outer peripheral part.

For this reason, since there is no water-resistant property, in a cord-type cable using a loose-type optical fiber cord, when water enters somewhere in one place, a phenomenon of so-called running water in which water is transmitted between the tensile strength fibers of the tensile strength fiber layer occurs.
For this reason, when using it outdoors etc., since it covered and used with the aluminum pipe etc., there existed a fault that cost became high.
JP-A-9-243877

  An object of the present invention is to provide a loose type optical fiber cord capable of preventing running water without using an aluminum pipe in view of the above-described conventional drawbacks.

The above and other objects and novel features of the present invention will become more fully apparent when the following description is read in conjunction with the accompanying drawings.
However, the drawings are for explanation only and do not limit the technical scope of the present invention.

In order to achieve the above object, the present invention provides a loose optical fiber comprising an optical fiber core, a tensile fiber layer covering the outer periphery of the optical fiber core, and a jacket covering the outer periphery of the tensile fiber layer. In the cord, at least one water-absorbing yarn is provided in the tensile strength fiber layer to constitute a loose type optical fiber cord.

  As is clear from the above description, the present invention has the following effects.

(1) In a loose type optical fiber cord comprising an optical fiber core, a tensile fiber layer covering the outer periphery of the optical fiber core, and a jacket covering the outer periphery of the tensile fiber layer, Since at least one water-absorbing yarn is provided, the water-absorbing yarn expands by absorbing water when water enters the tensile-strength fiber layer, and can effectively prevent water from entering other than the site where water has entered. it can.

(2) According to the above (1), since it is only necessary to provide at least one water-absorbing yarn in the tensile strength fiber layer, it can be easily manufactured.

(3) Since it has water absorption characteristics according to the above (1), it can be used for an optical fiber cord of a cord type fiber cable, a flat cable, and an optical fiber cable. Can be a cable.

(4) In claim 2, the same effects as in the above (1) to (3) can be obtained.

(5) In claim 3, the same effects as in the above (1) to (3) can be obtained, and even if the jacket is pushed back to the connector, the force is not directly applied to the optical fiber core (spring back Absorbs light transmission characteristics.

  Hereinafter, the present invention will be described in detail with reference to the best mode for carrying out the present invention shown in the drawings.

  In the best mode for carrying out the present invention shown in FIGS. 1 and 2, reference numeral 1 denotes a loose type optical fiber cord having the water absorption characteristics of the present invention, and this loose type optical fiber cord 1 is an optical fiber core wire. 2, a tensile strength fiber layer 3 that covers the outer peripheral portion of the optical fiber core wire 2 with a plurality of tensile strength fibers so as to have gaps between the tensile strength fibers, and a jacket that covers the outer peripheral portion of the tensile strength fiber layer 3. 4 and three water-absorbing yarns 5, 5, 5 arranged at predetermined intervals in the tensile strength fiber layer 3.

In the loose type optical fiber cord 1 having the above-described configuration, when the outer jacket 4 is damaged and water enters the inside from the damaged portion, the water absorbing yarns 5, 5, 5 disposed in the tensile strength fiber layer 3 absorb water. It can expand and block running water to other parts.
As shown in FIG. 3, the loose type optical fiber cord 1 configured as described above includes an optical fiber cable 6 in which a part of the jackets 4 and 4 of the two loose type optical fiber cords 1 and 1 are connected. 4, tension members 7 and 7 are juxtaposed on both sides of the loose optical fiber cord 1, trapezoidal recesses 8 and 8 are formed at the upper and lower portions of the central portion, and notches 9 and 9 are formed at the center portions of both ends. A cord type optical fiber cable 11 covered with a rectangular sheath 10 formed with a tension member 7, 7 on both sides of two loose type optical fiber cords 1, 1 as shown in FIG. As shown in FIG. 6, a cord-type optical fiber cable 11A covered with a rectangular sheath 10 in which trapezoidal recesses 8 and 8 are formed in the upper and lower portions and notched portions 9 and 9 are formed in the center of both ends. Both tension members 7 A flat optical cable 12 in which two loose optical fiber cords 1 and 1 are juxtaposed in parallel, and an outer periphery thereof is covered with an elliptical sheath 10A, and a plurality of cables are provided so as to cover the outer periphery of the tension member 7A as shown in FIG. The loose type optical fiber cord 1 is arranged in at least one layer, in this embodiment two layers, and is used for an optical fiber cable 13 or the like whose outer peripheral portion is covered with a sheath 10B.
As shown in FIGS. 8 and 9, even the loose type optical fiber cord 1 </ b> A in which one water absorbing yarn 5 is disposed in the tensile strength fiber layer 3 has an effect of preventing running water.
The water absorbing yarn 5 can be a split yarn made of polypropylene.
As the tensile strength fiber, an aramid fiber such as Kevlar (registered trademark) can be used. The amount of Kevlar used varies depending on the diameter of the loose optical fiber cord, but when the diameter of the optical fiber core wire 2 is 0.9 mm, if the outer diameter of the loose optical fiber cord is 1.7 mm, about 3500 denier, If the outer diameter of the loose type optical fiber cord is 2 mm, it will be about 5000 denier, and if the outer diameter of the loose type optical fiber cord is 2.8 mm, it will be about 6500 denier. The amount of water absorbing yarn 5 is preferably 5 to 50% by weight of the tensile strength fiber. For example, when the optical fiber core wire 2 is a loose optical fiber cord having a diameter of 0.9 mm, an outer diameter of 2 mm, and a length of 10 m, and the included Kevlar is 5000 denier, the end can be finished in 10 minutes without the water absorbing yarn 5. However, when one 500 denier water-absorbing yarn 5 was included, the running distance was 2 m, and the effect of preventing running water appeared. When three 500 denier water-absorbing yarns 5 were included in a loose type optical fiber cord having the same dimensions, the running distance was less than 1 m, and the running prevention effect was further improved.
[Different forms for carrying out the invention]

  The second embodiment for carrying out the present invention shown in FIGS. 10 and 11 is mainly different from the best first embodiment for carrying out the present invention in that the tensile fiber forming the tensile fiber layer 3 is different from the first embodiment. The present invention is applied to the tensile fiber layer 3 using the tensile fiber impregnated or adhered with the water-absorbing polymer 14 in that a water-absorbing polymer 14 such as polyacrylate is used. The same effect as that of the first embodiment is obtained.

  The present invention is used in the industry of manufacturing loose type optical fiber cords.

1 is a perspective view of the best first embodiment for carrying out the present invention. The expanded sectional view which follows the 2-2 line of FIG. Explanatory drawing used for the optical fiber cable of the best 1st form for implementing this invention. BRIEF DESCRIPTION OF THE DRAWINGS Explanatory drawing used for the cord type optical fiber cable of the best 1st form for implementing this invention. BRIEF DESCRIPTION OF THE DRAWINGS Explanatory drawing used for the cord type optical fiber cable from which the 1st best form for implementing this invention differs. Explanatory drawing used for the flat optical cable of the best 1st form for implementing this invention. Explanatory drawing used for the optical fiber cable of the best 1st form for implementing this invention. The perspective view which has arrange | positioned the water absorption yarn. The expanded sectional view which follows the 9-9 line of FIG. The perspective view of the 2nd form for implementing this invention. The expanded sectional view which follows the 11-11 line of FIG.

Explanation of symbols

1, 1A: Loose type optical fiber cord,
2, 2: Optical fiber core wire,
3: Tensile fiber layer, 4: Outer jacket,
5: Water absorption yarn, 6: Optical fiber cable,
7, 7A: tension member, 8: trapezoidal recess,
9: Notch, 10, 10A, 10B: Sheath,
11, 11A: Cord type optical fiber cable,
12: Flat optical cable, 13: Optical fiber cable,
14: Water-absorbing polymer.

Claims (3)

In a loose type optical fiber cord comprising an optical fiber core, a tensile fiber layer covering the outer periphery of the optical fiber core, and a jacket covering the outer periphery of the tensile fiber layer, at least one in the tensile fiber layer A loose type optical fiber cord provided with at least one water absorbing yarn. In a loose type optical fiber cord comprising an optical fiber core, a tensile fiber layer covering the outer periphery of the optical fiber core, and a jacket covering the outer periphery of the tensile fiber layer, the tensile strength for forming the tensile fiber layer A loose type optical fiber cord characterized by impregnating or adhering a water-absorbing polymer to a fiber. The loose optical fiber cord with a connector according to claim 1, wherein a connector is attached to an end of the loose optical fiber cord and terminated.

Images