JPH01310306A - Post branching juncture of optical fiber cable - Google Patents

Abstract

PURPOSE:To prevent an increase in light transmission loss and buckling of fibers by mounting a reinforcing pipe to the exposed part of the spacer of a cable juncture. CONSTITUTION:A sheath 2 of the optical cable juncture is stripped to expose the spacer 3 and the coated optical fiber 5 to be branched is taken out and is cut. The cut fiber is connected to a coated branch fiber 7. The two-split reinforcing pipe 11 is mounted to the exposed part of the spacer 3 and is fastened by means of connecting bolts 2 at flange parts 11B. These juncture parts are housed in a connecting box 13. The protrusion of the spacer 3 into the connecting box is, therefore, prevented by the reinforcing pipe even if said spacer tends to project in said box. The increase in the transmission loss by curving of the spacer 3 is thus prevented and the buckling of the fibers is prevented.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a rear branch connection section of an optical fiber cable in which an optical fiber core is housed in a slot of a spacer and a sheath is coated on the outer periphery of the spacer. It is.

[Prior art] The post-branch connection of an optical fiber cable involves stripping off the sheath of the ophthalmic fiber cable over a required length at the point where the branch is required, exposing the spacer, and connecting the required branch to be branched from within the slot of the exposed spacer. Take out and cut the nine optical fiber cores, connect a branch optical fiber core to the cut end of the optical fiber core, and store the exposed portion of the spacer and the branch connection portion of the optical fiber core in a junction box. It is formed by

[Problems to be Solved by the Invention] However, in the conventional rear branch connection section of an optical fiber cable, the spacer protrudes into the connection box due to temperature changes during use, and the spacer bends in the connection box, causing internal damage. Abnormal bending stress acts on the optical fiber core, increasing transmission loss or causing optical failure. There was a problem that the fiber core wires buckled.

SUMMARY OF THE INVENTION An object of the present invention is to provide a rear branch connection section of an optical fiber cable that can prevent a spacer from bending inside a connection box.

[Means for Solving the Problems 1] In the present invention for achieving the above object, a reinforcing pipe is attached to the outer periphery of the spacer in the junction box.

"Function" When a reinforcing pipe is attached to the outer periphery of the spacer like this,
The spacer will not curve, and the optical fiber will not be adversely affected.

Embodiment 1 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. As shown in FIG. 1 and the third factor, the sheath 2 of the optical fiber cable 1 is stripped off to a required length at the location where the rear branch connection is to be made, and the spacer 3 is exposed. At this exposed location of the spacer 3, the optical fiber core 5 to be branched is taken out from inside the slot 4 of the spacer 3 and cut, and the branched optical fiber cable 6 is connected to the cut location of the optical fiber core 5. Fiber core 1! i17 is the core wire connection IW
Connected by 8. Branch-connected optical fiber core wire 5
The extra length portion 9 of the branched optical fiber core 7 is connected to the core wire connection portion 8.
It is stored in the extra length storage case 10 along with the length τ. A reinforcing pipe 11 split into two is attached to the outer periphery of the exposed part of the spacer (J 3).
are connected by tightening the flange portions 11B on both sides of the splitter 11A with connecting bolts 12. The core wire connection portion 8 is branch-connected in this way. Extra length 9. Sube 1
The exposed portion of J3 is housed within the junction box 13. The penetration portions of the optical fiber cable 1 and the branch optical fiber cable 6 at both ends of the junction box 130 are hermetically sealed by the end plate 14 divided into two and the sealing material 15. Furthermore, the sheath ends of the optical fiber cable 1 and the branched optical fiber cable 6 are fixed to the junction box 13 with fixing fittings 16 within the junction box 13 .

By reinforcing the exposed portion of the spacer 3 with the reinforcing pipe 11 in this way, even if the spacer 3 tries to protrude into the connection box 13 during use, the spacer 3 can be prevented from curving.

Note that the connection of the splitter 11A of the reinforcing pipe 11 can be done by other means, such as by using a connecting band 17 and setscrews 18 that fix both ends of the connecting band 17, as shown in FIGS. 4 and 5. can.

[Effects of the Invention] As explained above, in the rear branch connection part of the optical fiber cable according to the present invention, a reinforcing pipe is attached to the exposed part of the spacer in the junction box to reinforce the spacer. Even if the spacer tries to protrude into the connection box, the reinforcing pipe can prevent the spacer from curving. Therefore, according to the present invention, it is possible to prevent an increase in transmission loss and buckling of the optical fiber due to abnormal bending of the optical fiber due to the curvature of the spacer.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the rear branch connection part of an optical fiber cable according to the present invention, and FIGS.
A front view and a right side view of the reinforcing pipe used in the figure, and FIGS. 4 and 5 are a front view and a right side view of other examples of the reinforcing pipe. 1... Optical fiber cable, 2... Sheath, 3...
・Spacer, 4... Slot, 5... Optical fiber core wire, 6... Branch optical fiber cable, 7... Branch optical fiber core wire, 8... Core wire connection portion, 9... Extra length portion, 10... Extra length storage case, 11... Reinforcement pipe,
11Δ... split surface, 11B... flange part, 12.
...Connection bolt, 13...Connection box.

Claims (1)

[Claims] The sheath of an optical fiber cable is formed by storing an optical fiber in a slot of a spacer and covering the outer periphery of the spacer with a sheath, and the sheath is stripped off to a required length without cutting the spacer at a post-branch connection point. A predetermined coated optical fiber is taken out from within the slot at a location of the spacer exposed at the location where the sheath is stripped, a branched coated optical fiber is connected to the cut end of the coated optical fiber, and the coated optical fiber is connected to the cut end of the coated optical fiber, and the coated optical fiber is connected to the cut end of the coated optical fiber. In the rear branch connection part of the optical fiber cable, in which the exposed part of the optical fiber and the branch connection part of the optical fiber core are housed in a connection box, a reinforcing pipe is attached to the exposed part of the spacer in the connection box. A rear branch connection part of an optical fiber cable, characterized in that: