JPH05113510A - Optical cable - Google Patents

Abstract

PURPOSE:To facilitate splicing processing in a splicing box and to realize an optical cable whose workability is improved. CONSTITUTION:The parts A of three two-fiber coated optical fibers 1 are separated respectively and the parts B thereof are twisted and integrated. Two- fiber splicing connector 2 is attached to the separated coated optical fiber side and a six-fiber batch splicing connector 3 is attached to twisted ends which are integrated through a thermal contraction tube 4. The connector 3 is fixed on the splicing box of the optical fiber of a trunk line and a forward part from a branching part, which is pulled down, is wired by the separated coated optical fiber 1, and the connector 2 is fixed on the splicing box of a terminal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical cable, and more particularly to an optical cable suitable for a drop cable for dropping a drop line having a small number of cores from a trunk line or a wiring system to a terminal.

[0002]

2. Description of the Related Art Conventionally, as an optical cable used for a technique for pulling from a trunk line or a wiring system, for example, "Research Practical Use Report", Vol. 33, No. 3, No. 3 (1984), Nos. 531 to 544.
A cable having a small number of cores, such as a two-core wire, as described in the page is known. Further, for the connection of the optical cable used for such a drop, at the time when the above-mentioned document was submitted, a fusion splicing method was used in which the glass portion of the optical fiber was brought into close contact, heated, melted, and connected.

However, with regard to the connection of optical fibers, recently, connectors having excellent workability have been developed and are being used. For example, "Optics" Vol. 19 No. 5 (1990) No. 3
As described on pages 26 to 336, the optical connector used in the drop connection box and the DS in the subscriber's house
There is a U (digital service unit) or the like, and it is also considered that a connector is attached to an optical cable in a factory and additional work is performed in the form of a cable with an optical connector.

A conventional drop cable has a single core or a small number of cores of about two. On the other hand, when laying an optical cable in a subscriber system or in a building, it is generally necessary to lay each of such cables one by one, and workability is low. Further, when terminals are connected using an optical cable with a connector, the number of connectors at the connection portion on the trunk side becomes very large, and the optical cable and the optical connector are congested, resulting in poor workability. Further, when a large number of cores are dropped at one place of the main line, there is a problem that the number of connected connectors becomes very large and the connection box becomes huge.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an optical cable that facilitates connection processing in a connection box and improves workability. To do.

[0006]

According to a first aspect of the present invention, there is provided an optical cable in which a plurality of optical fiber core wires each accommodating one or a plurality of optical fibers are assembled, and one end side thereof is provided. In, a collective connection connector that can connect all these optical fibers at the same time is provided, and at the other end side,
It is characterized in that it is separated for each optical fiber core wire, and a connection connector is provided for each.

According to a second aspect of the present invention, in the first aspect of the invention, a plurality of optical fiber cores are formed by a band-shaped body in the section from the collective connector on one end side until the optical fiber cores are separated. The invention of claim 3 is characterized in that it is partially or continuously wound, and in the invention of claim 1, in the invention of claim 1, from the collective connection connector on one end side, it is separated for each optical fiber core wire. In the section (1), the tube is attached to the plurality of optical fiber core wires.

[0008]

Since the optical cable having such a structure is used, 1
Wrap this cable around one coil or drum,
One end or the end where it is held in the installation site from the middle and where multiple optical fiber cores are integrated can be connected to a connection box or connection board with a collective connector, and the other end can be pulled down by guiding it to the end of the line. Can be done.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1A is a schematic configuration diagram of a first embodiment of an optical cable of the present invention. In the figure, 1 is an optical fiber core wire, 2 is a connector having a small number of cores, 3 is a multi-core collective connection connector, 4 is a heat-shrinkable tube, A part is a part where the optical fiber core wire is separated, and B is a part. The part is an integrated part. In this embodiment, since the optical fiber core wire 1 is a two-core optical fiber core wire having two optical fibers, the connector 2 has two cores. Further, since the three 2-fiber optical fibers are used, the collective connection connector 3 has 6 fibers. In the three two-fiber optical fibers, the A part up to the middle is separated, and the B part from the middle is twisted and integrated. The twisted ends are integrated by a heat-shrinkable tube 4, and the collective connection connector 3 described above is attached.

A specific example will be described. A cross-sectional structure is shown in FIG. 1 (B), and a two-core tape core wire 5 having a major axis of 0.7 mm and a minor axis of 0.4 mm, in which two optical fibers having an outer diameter of 250 μ are integrated, was used. Three 1140 denier Kevlar fibers 6 were vertically attached to this, and a vinyl chloride resin 7 was coated to obtain a 2-fiber optical fiber 1 having an outer diameter of 3 mm. This optical fiber core wire 1 having a length of 120 m is prepared, and three fibers are prepared.
In the portion B of (A), three pieces were arranged in an equilateral triangle, and a section of 60 m was twisted with a pitch of 350 mm. After the terminals 150 mm on the twisted side are integrated so as not to be separated by the heat-shrinkable tube 4, the 6-core collective connector 3
Was introduced to configure the terminal. Two connectors were attached to the other terminal for each optical fiber. The size of each connector is more than the number of optical fibers connected.
Rather, it depends on the mechanical structure of the workable connector, so that the size of the two-core type or the six-core type does not change. Therefore, by using the optical cable of the present invention, the number of connectors on the trunk side is reduced to 1/3 and the space occupied by the connectors is reduced to 1/3.

FIG. 2 is a schematic configuration diagram of a second embodiment of the optical cable of the present invention. In the figure, the same parts as those in FIG. 8 is a fixed part. In this embodiment, the optical fiber core wire 1 in the first embodiment is used.
The parts that are integrated by twisting are integrated by a fixture 8 that can be attached and detached in parallel without twisting.

FIG. 3 is a schematic configuration diagram of a third embodiment of the optical cable of the present invention. In the figure, the same parts as those in FIG. 9 is a fixed tube with a slot. Also in this embodiment, the optical fiber core wires 1 are arranged in parallel. The fixed tube 9 is used and the optical fiber core wire 1 is inserted from the slot and housed in the fixed tube.

In the first embodiment, since the contact area between the cables is large due to the twisting, and the strength of integration is strong, the strength is excellent, while the second and third embodiments are performed. An example is that the integrated portion can be easily separated, and it is excellent in that the length of the separated portion can be easily adjusted if necessary. Of course, in the first embodiment, it is possible to adjust the length of the separated portions by untwisting the twisted and integrated portions.

FIG. 4 is a schematic configuration diagram of a fourth embodiment of the optical cable of the present invention. In the figure, the same parts as those in FIG. 11 is a tensile strength line. In this embodiment, the tensile strength wire 11 is integrated with the integrated portion of the optical cable. The optical cable of this embodiment has a structure in which the tensile strength wire 11 is used for a structure such as a utility pole especially when it is necessary to increase the strength at the time of laying and after laying, such as when the integrated portion is laid aerially. It is useful because it can be fixed to. As the tensile strength wire 11, an appropriate material such as a galvanized steel wire can be used, but as a specific example, three 2-core optical cable core wires with an outer diameter of 3 mm are provided outside a galvanized steel wire with an outer diameter of 12 mm. It was possible to get good results by twisting.

FIG. 5 is an explanatory diagram in which the optical cable having the length of 120 m described in FIG.
In the figure, 12 is a wiring cable, 13 is a connection box, 14 and 15
Is a utility pole, 16a, 16b and 16c are houses, 17 is an integrated part of an optical cable, 18 is a multi-core collective connection connector, 19 is an extra length of the integrated part, 20 is a drawing part, 2
1a, 21b, 21c are separated optical fiber core wires, 2
2a, 22b, 22c are extra lengths of the optical fiber core wire, 23
Reference characters a, 23b, and 23c are two-core connection connectors. The wiring cable 12 is suspended on a telephone pole 14 and a connection box 13 is installed. A route from the utility pole 14 to the utility pole 15 that is 50 m away is a route without branching, and a case where the optical cable is divided and introduced from the utility pole 15 to the three houses 16a, 16b, and 16c will be described.

First, the branch point of the optical cable is retained as the detention section 20 on the utility pole 15, the integrated portion 17 side of the optical cable is pulled to the utility pole 14 side, and is suspended and fixed. 18 was fixed to the connection box 13. Although the extra length 19 is collected in the utility pole 14, it may be housed in the connection box 13. Next, from the utility pole 15 to the houses 16a, 1
6b and 16c respectively have optical fiber cores 21a and 21
b and 21c were pulled and fixed. After connecting the two-core connector 23a, 23b, 23c to the subscriber box on the wall of each house, the extra lengths 22a, 22b, 2 of each optical fiber core wire are connected.
2c was bundled and stored in the subscriber box. In this example, the distances from the utility pole 15 to the houses 16a, 16b, and 16c are 30 m, 40 m, and 50 m, respectively, and the separated optical fiber core wires are 60 m, so that sufficient wiring can be performed, Wiring was completed by performing extra length processing.

In this way, the optical cable can be laid once in a portion passing through the same route, such as between the electric pole 14 and the electric pole 15, and the working efficiency can be greatly improved. Also, the optical cable connected to the connection box looks like one
It has a beautiful appearance. If you connect the optical cables one by one,
Although the previously connected optical cable has a problem that it interferes, the optical cable of the present invention does not have such a problem, and it has been confirmed that the workability is high.

[0018]

As is apparent from the above description, according to the present invention, the following effects can be expected. It is possible to lay a plurality of optical cables in a portion that follows the same route at one time. The optical cables in the connection box can be connected at once by the multi-core collective connection connector. The space on the connection box required for connecting the connector can be made sufficiently small. It is possible to process once when the excess length of the optical cable occurs near the connection box. Since it is possible to prevent the congestion of the cables around the connection box including the fixing members for the optical cables such as telephone poles, it is advantageous for the subsequent connection of the optical cables to the connection box. In the section from the connection box to the dividing point, multiple optical fiber cores are integrated, so the strength in this section is higher than in the case of a single optical fiber core, and the optical length becomes longer. This is effective in cases such as subscriber systems.

Therefore, the optical cable of the present invention is useful as an optical cable having excellent laying workability, for example, when the laying section has an area that follows the same route, such as an optical subscriber withdrawal or a premises wiring.

[Brief description of drawings]

FIG. 1A is a schematic configuration diagram of a first embodiment of an optical cable of the present invention, and FIG. 1B is a sectional view.

FIG. 2 is a schematic configuration diagram of a second embodiment of the optical cable of the present invention.

FIG. 3 is a schematic configuration diagram of a third embodiment of the optical cable of the present invention.

FIG. 4 is a schematic configuration diagram of a fourth embodiment of the optical cable of the present invention.

FIG. 5 is an explanatory diagram of a usage situation of the optical cable of the present invention.

[Explanation of symbols]

 1 optical fiber core wire 2 connector with a small number of cores 3 collective connector with multiple cores 4 heat-shrinkable tube 5 2 core tape core wire 6 Kevlar fiber 7 vinyl chloride resin 8 fixing part 9 fixing tube 11 tensile strength wire

Front page continuation (72) Inventor Wataru Watanabe 1 Taya-cho, Sakae-ku, Yokohama-shi, Kanagawa Sumitomo Electric Industries, Ltd. Yokohama Works (72) Inventor Shigeru Tanaka 1-Taya-cho, Sakae-ku, Yokohama, Kanagawa Sumitomo Electric Industries Co., Ltd. Company Yokohama Works (72) Inventor Shigeru Tomita 1-1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corporation

Claims (3)

[Claims] 1. An optical cable in which a plurality of optical fiber core wires containing one or a plurality of optical fibers are assembled, and a collective connection connector capable of simultaneously connecting all of these optical fibers is provided at one end side, On the other end,
An optical cable, characterized in that it is separated for each optical fiber core and a connection connector is provided for each. 2. A plurality of optical fiber cores are partially or continuously wound by a strip in the section from the collective connection connector on one end side to the separation of each optical fiber core. The optical cable according to claim 1, which is characterized in that. 3. A tube is attached to a plurality of optical fiber core wires in a section from the collective connector on one end side to the separation of each optical fiber core wire. Optical cable described in.