JPH01297609A - Optical wiring cable - Google Patents

Abstract

PURPOSE:To facilitate and stabilize post branching of arbitrary optical fibers in two fiber unit by housing an optical unit which is formed by adhering and fixing sepn. type optical fiber units integrally coated with two-fiber optical fibers together with tearing cords to the outside circumference of a central body into the grooves of a groove spacer. CONSTITUTION:The optical unit 4 has the structure in which plural pieces of the sepn. type optical fiber units 1 each formed by integrating the two-fiber optical fibers 11 and the tearing cord 12 and applying a covering 13 thereto as a secondary covering are adhered and fixed by an adhesive agent 3 to the outside circumference of a central body 2 which is periodically twisted right and left. The optical units 4 are housed into the grooves 6 of the grooved plastic spacer 5 contg. a tensile body 7. The post branching to take out the arbitrary optical fibers in the two-fiber unit is thereby easily executed.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an optical distribution cable used in an optical subscriber line network, and particularly relates to a spacer-type optical distribution cable that accommodates 26 separate optical fiber units. It is.

[Conventional technology]

Conventionally, there are various types of optical distribution cables whose cross-sectional structures are shown in FIGS. 4a to 4d as optical distribution cables used in this type of optical subscriber line network.

FIG. 4a shows a plurality of optical units 40 in which a plurality of optical fibers 41 are assembled around the outer periphery of a central tensile strength member 42, and a plurality of optical units 40, six in this example, are arranged around a tensile strength member 44. It has a structure that gathers around the outer periphery.

FIG. 4 shows a spiral groove formed on the outer periphery of a plastic spacer 471, in which a plurality of tape-shaped optical fiber core wires 45, in which a plurality of optical fibers are collectively coated in a tape-shape, are formed, four in this example. It has a structure in which the parts are stacked and housed in 46.

FIG. 4C shows a structure in which an optical fiber 41 is housed in the groove of an optical fiber housing grooved spacer 472, which has cut grooves 48 in consideration of branching after the cable is laid, such as when branching is performed as necessary. belongs to.

FIG. 4d shows a coating 50 in which two optical fibers 41 and tear strings 49 used for optical fiber separation are collectively coated as unit components of an optical distribution cable used in an optical subscriber line network.
This is an example of a two-separate optical fiber unit 400.

[Problem to be solved by the invention]

There is a need for a structure that can be easily stored and later branched. Conventional optical distribution cables having the structures shown in FIGS. 4a to 4C and simply collecting multiple separate optical fiber units shown in FIG. However, it is difficult to take out individual optical fibers as needed and handle them later for branching. There is a problem with handling as a distribution cable.

The present invention solves the conventional problems, allows easy and stable branching of arbitrary optical fibers in units of 26 after cable installation, and creates an optical distribution cable with a high-density storage structure. The purpose is to provide

[Means to solve the problem]

In order to achieve the above object, the present invention provides an optical distribution cable for use in a subscriber line network, in which a plurality of separate optical fiber units are provided, in which two-core optical fibers and tear strings are collectively coated with a secondary coating of resin. It is characterized by having a structure in which an optical unit is housed in a groove of a grooved spacer, which is formed by adhering with adhesive to the outer periphery of a twisted center body that is reversed left and right at regular intervals.

[Action]

In an optical subscriber line network, a method of branching midway is used depending on the subscriber's request, but the optical distribution cable of the present invention has a protective coating such as loose winding on the optical unit stored in the groove of a grooved spacer made of plastic. Because the split optical fiber unit that makes up the optical unit has a twist that reverses in both directions, it can be used as desired without having to take out the entire optical unit from the groove of the plastic spacer when branching midway. of optical fibers can be easily extracted in units of 26, which is the basic unit of optical fiber communication systems. Further, since the unbranched optical fiber remains housed in the groove of the spacer, there is no need to process the extra length in the junction box used for branching, and the post-branching handling is excellent.

Furthermore, the optical unit has a small diameter, and the optical fibers of the optical cable can be housed in high density.

Examples will be described below based on the drawings.

〔Example〕

FIG. 1 is a sectional view of an embodiment of an optical unit applied to the optical distribution cable of the present invention. The optical unit 4 of this embodiment has two
The core optical fiber 11 and the tear string 12 are assembled into a separate optical fiber unit 1 with a secondary coating 13 made of, for example, resin, and a central body 2 made of, for example, a BP wire periodically twisted left and right. It has a structure in which a plurality of wires, six in this embodiment, are bonded and fixed to the outer periphery using an adhesive 3 made of, for example, an ultraviolet curable resin.

In the optical unit of this structure, by releasing the pattern of the center body 2, the detachable optical fiber unit, which is adhesively fixed to the center body 2 in a twisted state, becomes twisted in the reverse direction. It is in a state where it is adhered to the central body 2. Furthermore, since the separable optical fiber unit 1 is bonded to the center body 2, the entire outer periphery is not roughly wound.

FIG. 2 shows an outline of the side structure of the optical unit 4.

The same reference numerals as in FIG. 1 indicate the same parts.

FIG. 3 is a cross-sectional view of an embodiment of an optical distribution cable in which an optical unit of the present invention is housed in a groove of a grooved spacer. In the optical distribution cable of this example, a plurality of separable optical fiber units are adhesively fixed to the outer periphery of a central body that is twisted left and right at regular intervals, and the twist is reversed when the central body is untwisted. The optical unit 4 is housed in a groove 6 of a grooved spacer 5 made of plastic and has a built-in tensile strength member 7. An optical distribution cable designed for high-density storage of optical fibers is constructed.

(Effects of the Invention) As explained above, the optical distribution cable of the present invention is a split-type optical fiber in which a two-core optical fiber, which is a basic unit of an optical subscriber line network in an optical fiber communication system, is coated together with a tear string. The optical unit is fixed with adhesive to the outer periphery of a center body that is twisted left and right at regular intervals, and is housed in the groove of a grooved spacer. When the center body is untwisted, it can be separated. Since the optical fiber unit is twisted in the reverse direction and is adhesively fixed to the center body, it is housed in the groove of the grooved spacer without the need for any rough winding around the outer periphery of the optical fiber unit. Therefore, it is possible to easily take out arbitrary optical fibers in units of 26 and then split them without having to take out the entire optical unit from the groove of the spacer during branching, and the optical fibers that are not to be branched can be left in the groove of the spacer. This eliminates the need to process excess length in the junction box for branching, making it easier to handle after branching.Furthermore, the small diameter of the optical unit makes it possible to use optical distribution cables that store optical fibers in high density. Can be provided.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of an optical unit according to the optical distribution cable of the present invention, FIG. 2 is a side view of the optical unit according to the optical distribution cable of the present invention, and FIG. 3 is a cross-sectional view of an embodiment of the optical distribution cable of the present invention. FIGS. 4a to 4d are cross-sectional views of examples of conventional optical distribution cables. 1.400...separable optical fiber unit, 11゜4
1... Optical fiber, 12.42... Tear string, 13
゜50...Coating, 2...Central body, 3...Adhesive,
4.40... Optical unit, 5... Grooved spacer, 6
．． 46... Grooved spacer, 7.44... Tensile strength body,
42... Central tensile strength body, 43... Rough winding, 45...
Tape-shaped optical fiber core wire, 471, 472... Spacer, 48... Cut groove 4 Optical unit Optical Nisoto sectional view No. 1 related to the optical wiring cable of the present invention
1 Figure 4: A diagram of a unit according to the optical wiring cable of the present invention.
2 Figure 3 c d Cross-sectional view of an example of a conventional optical distribution cable Figure 4

Claims (1)

[Claims] In an optical distribution cable for a subscriber line network, a plurality of separable optical fiber units in which two-core optical fibers and tear strings are collectively coated with a secondary coating with resin,
An optical wiring cable characterized in that an optical unit is housed in a grooved spacer by adhering an optical unit to the outer periphery of a twisted central body that reverses left and right at regular intervals with adhesive.