JPS58207018A - Method for branching photoconductor of optical cable - Google Patents

Abstract

PURPOSE:To make easier the branching and connecting works of optical cables, by exposing a photoconductor to be branched by removing the outer cover of an optical cable at a proposed branching point and cutting off the photoconductor to be branched after removing the outer cover of the optical cable at a point which is located at the distance of excess length necessary for the connecting work from the branching point. CONSTITUTION:In the first place, the outer cover 13 of the optical cable 1 is removed at the branching point 2 and a pipe 110 containing the photoconductor 100 to be branched is cut crosswise so that the photoconductor 100 contained in the pipe 110 is not spoiled. Then the outer cover 13 of the cable 1 at a position 5 at a distance equal to the excess length necessary to the connecting work 100a from the branching point 2 is removed and the photoconductor 100 is cut off together with the pipe 110. The cut photoconductor of the excess length is pulled out at the branching point 2, introduced to a connecting device installed near the branching point 2, and connected with a photoconductor 3 for local wiring at a connecting part 4. The cut position 5 of the photoconductor 100 is protected by putting a packing 7, such as compound, etc., in the part from which the cable cover 13 is removed and covering the packing with a sleeve 6.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for branching light guides in an optical cable.

After the optical cable is installed, the optical conductor may be branched to increase the number of terminals, etc. At the branch point, the cable jacket is removed and the optical conductor to be branched is taken out and connected to the optical guide for local wiring.

By the way, when connecting light guides, the connecting device is installed at a stable position near the branching point of the optical zoom, and the light guides to be connected are guided to the connecting device.

At that time, ``In order to provide enough leeway to prevent unnecessary tension or bending from being applied to the light guide, an extra length for branching and connection work is required, which can be approximately 1 to 2 meters.

Therefore, when branching a light guide in the middle of an optical cable,
The cable jacket must not be removed for that long to provide extra length for branch connections. In the case where the cable sheath has already been removed, it must be covered with a protective body instead of the cable sheath after the branch connection work, or when a branch box is used as a protector, the shape of the branch box becomes long, resulting in high cost and handling. Undesirable due to inconvenience etc. In addition, all the light guides of the existing optical cable are cut at a glance, and the light guides to be branched are branched and connected there. On the other hand, in order to restore the line, an optical cable is inserted into the remaining optical conductor that is not branched (2) as a connection extra length, and the optical conductor of the divided optical cable and the optical conductor of the cut cable are connected.

However, since it is necessary to temporarily cut the non-branching optical conductor and connect it at two places to restore it, the number of connections increases, which not only affects the transmission characteristics but also takes time and effort to connect. Undesirable.

The present invention has been made in view of the above problems, and it is possible to branch an optical fiber in the middle of an optical cable in which the optical fiber is retractably housed, without requiring a split optical cable, and by reducing the length of the removed portion of the cable jacket. The present invention provides a method for branching an optical cable guide body, which shortens the length of the optical cable and facilitates the branch connection work, by removing the outer sheath, etc. of the optical cable at the branch point of the optical cable, which is housed so that the optical cable can be pulled out. to expose the light guide to be branched, and remove the jacket etc. of the optical cable at a position at least an extra length of light guide connection from the branch point to cut the light guide to be branched, and then cut the light guide to branch. The extra length of the optical waveguide is pulled back to the branch point.

Embodiments of the present invention will be described in detail below with reference to the drawings.

The drawings are explanatory diagrams for explaining a method for branching a guide body in an optical cable according to the present invention.

In the figure, l is an optical cable having a light guide 〈〉, which is a known type having a core, a cladding layer, a protective layer, etc. in order from the center outward. Reference numeral 11 denotes a pipe made of polyamide resin or the like that houses the light guide 1o, and the leading body 10 has a space 12 inside the pipe Il.
The light guide 10 is loosely inserted through the pipe 11, and the light guide 10 can be pulled out from the pipe 11 after a distance of several meters to several tens of meters. Reference numeral 13 denotes a cable sheath, which is provided on the optical fiber assembly 10 and is made of a restraining layer, a metal sheath, a plastic sheath, or the like. In addition, in the embodiment described in F, the optical cable 1 in which the optical cable 10 is housed so that the optical cable 10 can be pulled out is shown in which the optical cable 10 is loosely inserted into the pipe 11 with a space 2. In addition to the above-mentioned optical cable l used in the invention, the present invention can be applied to any optical cable that is removably housed in a light guide.

100 is the light guide to be branched, +00a is the extra length for connection work of the light guide +00 to be branched, +10 is the light guide 100
It is a pipe that is inserted through the 2 is a branch point provided for expansion, etc., 3 is a light guide for local wiring, and 4 is a connection portion between the light guide 100 to be branched and the light guide 3 for local wiring. The light guide 100 to be branched is long, including the extra connection length 100a required to connect with the guide body 3,
In order to prevent excessive bending or tension from being applied to the light guides +00 and +3, they are stored in a loop shape in the branch box 20.

5 is the cutting position of the light guide 100 to be branched, which is provided at a position separated by the total connection length 100a from the branch point 2, and the cable jacket 13 is removed, and the light guide to be branched +0
0 is exposed and cut. Reference numeral 6 denotes a sleeve provided to cover the removed portion of the cable jacket 13 after cutting the optical conductor +00 to be branched as described above in order to repair and protect the portion. 7 is a filler such as a compound provided inside the sleeve 6.

First, the procedure for forming this embodiment will be explained.

At the branch point 2, the cable jacket 1 of the optical cable 1 is removed.
3 is removed, and the pipe 110 housing the light guide 100 to be branched is cut into rounds with a knife or the like so as not to damage the light guide 100 inside. +10 indicates the cut point of the pipe. Therefore, the remaining length of connection to the light guide 100 to be branched is 1
In order to take 00a, remove the cable jacket 13 at position 5, which is a distance equivalent to the connection length 00a from the branching point 2, and cut the light guide 00 along with the pipe 110 that accommodates the leading body +00 to be branched as appropriate. Cut with a tool such as nippers.

The extra connection length 100a cut at position 5, which is separated by the extra connection length 100a, is pulled back at the branch point 2. A connection device (not shown) in which the optical conductor +00 with the extra connection length 100a is installed in a stable position near the branch point 2 of the optical cable l.
and connect it to the light guide 3 for local wiring. Although not shown, suitable pipes may be inserted through the light guides 100a and 3 for protection. As described above, at the cutting position 5 of the optical guide 100, the removed portion of the cable sheath 13 is protected by a sleeve 6 and a known method such as a compound.

In the present invention, the length of the cable sheath that is removed in order to branch the light guide 100 and to cut the light guide 100 is extremely short, as is clear from the above description.
For example, about 10 to 30 cM is sufficient.

It should be noted that although the above description has been made regarding a method of branching light guides in an optical cable having only light guides, the present invention may also be applied to an optical cable including an electrical conductor. When the light guide is housed in a pipe as in the embodiment, it can be pulled out for quite a long time, so the light guide for wiring to the terminal etc. can be pulled back at the branch point without connecting to the light guide for local wiring. It is also possible to cover the branched light guide with a pipe member other than the above-mentioned pipe and guide it to a location remote from the branch point.

As described above, the method for branching a guide member in an optical cable according to the present invention does not require a split optical cable, does not require any effort for connection, and shortens the cable sheath removal portion, making the work easier. Furthermore, although the number of connection points is small, the transmission characteristics do not deteriorate.

[Brief explanation of the drawing]

The drawings are explanatory diagrams for explaining a method for branching a guide body in an optical cable according to the present invention. In the figure, 1 is the optical cable, 2 is the branch point, 5 is the cutting position of the light guide to be branched, which is a distance equivalent to the extra connection length from the branch point, 100 is the light guide to be branched, +00 a is the light guide to be branched +00 The remaining length of connection work is shown respectively. Patent applicant: Dainichi Nippon Electric Cable Co., Ltd. Representative Director: Yukio Aoyama

Claims (1)

[Claims] At the branching point of the optical cable of the optical cable housed in a manner that allows the optical cable to be pulled out, the outer sheath of the optical cable is removed to expose the optical conductor to be branched, and at least a portion of the optical cable for connecting the guide is removed from the branching point. An optical cable characterized in that, after removing the outer sheath or the like of the optical cable at a long distance position and cutting the optical conductor to be branched, the extra length of the optical conductor to be branched is pulled back to the branching point. A method for branching the leading body in “.