JPH0519130A - Optical fiber cable connecting part - Google Patents

Abstract

PURPOSE:To slimly form a surplus length part, and to obtain an optical fiber cable connecting part which is slim and whose cost is low by providing a switchback connecting part in a surplus length part of a coated optical fiber, and forming the surplus length part by folding the switchback connecting part as a folding end. CONSTITUTION:In an optical fiber cable connecting part 3, a switchback connecting part 9 is provided in a surplus length part 8 of a coated optical fiber 6, and the surplus length part 8 is formed by folding the switchback connecting part 9 as a folding end. In this regard, as for the switchboard connecting part 9, both tips of two pieces of coated optical fibers 6 whose tips are arranged in the same direction are fused mutually in parallel and a fixed part is formed, and in its tip, a reflector is provided. Accordingly, the surplus length part 8 of the coated optical fiber 6 can be formed slimly, and a connecting box 4 for containing the coated optical fibers 5, 6, a coated fiber connecting part 7, the surplus length part 8, the switchback connecting part 9, etc., can be formed slimly.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber cable connecting portion in which optical fiber core wires of both optical fiber cables are connected at a core wire connecting portion in a connection box.

[0002]

2. Description of the Related Art FIG. 4 shows an example of a conventional optical fiber cable connecting portion 3 in which a branch cable 2 is connected to a trunk cable 1. The optical fiber cable connecting portion 3 is
The optical fiber core wire 5 of the trunk cable 1 is cut in the connection box 4, and the tip of the optical fiber core wire 6 of the branch cable 2 is butted against the end of the optical fiber core wire 6 to provide a core wire connecting portion 7 at this time. The structure is such that the extra length portion 8 of the optical fiber core wire 6 is provided between the optical fiber core wire 2 and the core wire connecting portion 7. The extra length portion 8 cuts the optical fiber core wires 5 and 6 on both sides of the core wire connecting portion 7 to change the connection when the connection of the optical fiber core wires 5 and 6 is changed. This is because the lengths of the fiber core wires 5 and 6 gradually decrease. In order to prevent breakage and deterioration of transmission characteristics, the extra length portion 8 is looped with a bending radius larger than the allowable bending radius of the optical fiber core wire 6 and is housed in the connection box 4.

[0003]

However, in the optical fiber cable connecting portion 3 having the looped extra length portion 8 as described above, since the looped extra length portion 8 extends, the connection box 4 is large in size. However, there was a problem that the cost increased.

It is an object of the present invention to provide an optical fiber cable connecting portion which can form an extra length portion of an optical fiber core wire in a slim shape.

[0005]

To explain the constitution of the present invention for achieving the above object, the present invention is to connect the optical fiber core wires of both optical fiber cables at a core wire connection portion in a connection box. In the optical fiber cable connection portion in which the optical fiber core wire on either the left or right side of the portion is provided with an extra length portion, a switchback connection portion is provided in the extra length portion of the optical fiber core wire, and the extra length portion is provided. Is formed by being folded with the switchback connection portion as a folding end.

[0006]

As described above, when the switchback connecting portion is provided in the extra length portion of the optical fiber core wire and the extra length portion is formed by folding the switchback connection portion as the folding end, the extra length portion of the optical fiber core wire is widened. It can be formed slim without taking.
Therefore, the connection box for accommodating them becomes slimmer than the conventional one and can be formed at low cost.

[0007]

Embodiments of the present invention will now be described in detail with reference to the drawings. In addition, in the part corresponding to the above-mentioned conventional example,
The same reference numerals are given.

FIG. 1 shows a first embodiment of an optical fiber cable connecting portion 3 according to the present invention. In the optical fiber cable connecting portion 3 of the present embodiment, the switchback connecting portion 9 is provided in the extra length portion 8 of the optical fiber core wire 6, and the extra length portion 8 is provided.
Is formed by folding the switchback connection portion 9 as a folding end.

As shown in FIG. 2, the switchback connection portion 9 is formed by fusing both ends of two optical fiber core wires 6 arranged with their ends in the same direction in a juxtaposed state by fusing each other. And a reflector 11 is provided at the tip of the fusion-bonded portion 10. The reflector 11 is formed by applying a metal coating, a dielectric multilayer film, or the like to the tip of the fusion-bonded portion 10.

In such a switchback connection section 9,
The light incident from the side a of the optical fiber core wire 6 is reflected by the reflector 11 and moves 100% to the side b.

As described above, the extra length portion 8 of the optical fiber core wire 6 is used.
If the switchback connection portion 9 is provided on the above and the extra length portion 8 is formed by folding the switchback connection portion 9 as a folding end, the extra length portion 8 of the optical fiber core wire 6 can be formed slim. Therefore, the connection box 4 accommodating the optical fiber core wires 5 and 6, the core wire connection portion 7, the extra length portion 8, the switchback connection portion 9 and the like is also slimmer than the conventional one and can be formed at low cost.

FIG. 3 shows a second embodiment of the optical fiber cable connecting portion 3 according to the present invention. In the optical fiber cable connecting portion 3 of the present embodiment, the optical fiber core wire 5 is connected to the optical fiber core wire 12 via the core wire connecting portion 7 to form an extra length portion 8, and four switches are provided in the extra length portion 8. The example in which the back connection portion 9 is provided and the adjacent switchback connection portions 9 are sequentially folded in the opposite direction is shown. By doing so, even a considerably long extra length portion 8 becomes very compact due to folding.

[0013]

As described above, in the optical fiber cable connecting portion according to the present invention, the switchback connecting portion is provided in the extra length portion of the optical fiber core wire, and the extra length portion is formed by folding the switchback connecting portion. As it is folded and formed as
The extra length portion of the optical fiber core wire can be formed to be slimmer than the conventional one. Therefore, the connection box for accommodating them is also slim and can be formed at low cost. Therefore, according to the present invention, it is possible to provide a slim and low-cost optical fiber cable connection portion.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a first embodiment of an optical fiber cable connecting portion according to the present invention.

FIG. 2 is a side view of a switchback connection portion used in this embodiment.

FIG. 3 is a vertical sectional view of a second embodiment of an optical fiber cable connection portion according to the present invention.

FIG. 4 is a vertical cross-sectional view of a conventional optical fiber cable connection part.

[Explanation of symbols]

1 ... Trunk line cable, 2 ... Branch line cable, 3 ... Optical fiber cable connection part, 4 ... Junction box, 5, 6 ... Optical fiber core wire, 7 ... Core wire connection part, 8 ... Extra length part, 9 ... Switchback connection part, 10 ... Fusion part, 11 ... Reflector, 12 ... Optical fiber core wire.

Claims (1)

Claim: What is claimed is: 1. An optical fiber core wire of both optical fiber cables is connected at a core wire connection portion in a connection box, and the optical fiber core wire on either side of the core wire connection portion has a margin. In the optical fiber cable connection portion provided with a long portion, a switchback connection portion is provided in the extra length portion of the optical fiber core wire, and the extra length portion is formed by folding the switchback connection portion as a folding end. The optical fiber cable connection part characterized by having.