JPS63200103A - Structure body for optical fiber cable branch part - Google Patents

Abstract

PURPOSE:To easily and quickly branch an optical fiber cable and to prevent the damage of a branch fiber by attaching a branch fiber protective tube, through which the branch fiber branched from the cable should be inserted, through a connection tool. CONSTITUTION:A connection tool 35 is inserted into an aperture end part 52 of a branch tube part 10 through a slip-off stopping mechanism N and has a through hole 53 through which a branched fiber F is inserted, and a front end part 54 is inserted to a base end part 55 of a branched fiber protective tube 36, and the branched fiber protective tube 36 is attached to a case body 5. That is, the connection tool 35 consists of a cylinder body which has an outer colar-shaped projecting part 34 in the base end part, and the projecting part 34 is fitted to a recessed groove 57 formed on an inside peripheral surface 56 of the aperture end part of the branch tube part 10 to insert the connection tool 35 so that this tool 35 is not slipped out of the aperture end part 53 of the branch tube part 10. In this case, recessed and projecting parts 57 and 34 constitute a slip-off stopping mechanism. Thus, the branch fiber F is always protected from the external and is prevented from being damaged to hold the branch fiber protective tube 36 in a case body 5.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a branch structure for an optical fiber cable.

[Conventional technology and its problems]

Generally, when branching an optical fiber cable or optical fiber unit of an optical fiber cable having a plurality of coated optical fibers or optical fiber units inside the sheath, the coated optical fibers are separated from the sheath at the branching part. Alternatively, after exposing the optical fiber unit and taking out the optical fiber core or the branched fiber of the optical fiber unit, the sheath is sealed from the outside.

However, since the cable is usually wired close to a wall or the like, sealing the cable becomes extremely difficult and there is a risk of damaging the branch fiber.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a branching structure for an optical fiber cable that can easily and quickly branch a branched fiber of an optical fiber cable without damaging the branched fiber.

[Means for solving problems]

The optical fiber cable branching structure of the present invention has a sheath that includes a plurality of optical fiber cores or optical fiber units. A branching structure for branching; the optical fiber coated wire or the optical fiber unit being coated at a predetermined portion of the cable, the coated optical fiber or the optical fiber unit exposed from the coated end of the sheath; a case main body having a branch pipe section for guiding the branch fiber to the outside; a case main body having an insertion hole installed in the open end of the branch pipe section of the case main body via a retaining mechanism and through which the branch fiber is inserted; and the distal end is inserted into the proximal end of the branched fiber protection tube,
A connector for attaching the branched fiber protection tube to the case body.

[Effect]

With the above configuration, the branch fiber protection tube through which the branch fiber branched from the cable is inserted is attached via the connector, so the branch fiber is always protected.
Furthermore, since this connector is housed inside the open end of the case body via a slip-off prevention mechanism, it will not slip out from the case body.

〔Example〕

Hereinafter, the present invention will be explained in detail based on drawings showing examples.

2, 5, and 6, reference numeral 1 refers to an optical fiber cable 4 having a plurality of optical fiber units 3 inside a sheath 2. This is an optical fiber cable branching structure for branching into an optical fiber cable, and includes a case main body 5 having a branch pipe section 10 that guides a branch fiber F of an optical fiber unit 3 to the outside, and a protective tube 36 through which the branch fiber is inserted. A connector 35 for attaching to the branch pipe portion IO of the case body 5 is provided.

The case body 5 is made of a cylindrical body whose diameters are reduced at both ends 6 and 7, and includes the branch pipe section 10 in the center thereof, which protrudes in a direction perpendicular to its axial direction. Furthermore, concave circumferential grooves 11 and 12 are formed in the end portions 6 and 7, respectively, and furthermore, the tips of the end portions 6 and 7 are each provided with a tapered surface 1.
3.14.

Specifically, this case body 5 has the following features as shown in FIG.
It is made up of a pair of half-split bodies 5a, 5a, each having a main body groove 15 with a substantially semicircular cross section and a branch groove 16 with a substantially semicircular cross section connected from the main body groove 15, and is separable. There is. Also, branch! ! The outer flange 17 is formed at the opening edge excluding both ends of the main body groove 15 and the tip of the branch groove 16.
From the back surface 17a of 7 to both ends of the main body groove 15 and the branch groove 1
Opening end surface 1B of the tip of 6, 19.20 is the mating surface 2
It is said to be 1. A packing 22 made of rubber or synthetic resin is interposed between the mating surfaces 21 and 21 of the half bodies 5a, 5a, so that the half bodies 5a, 5a are brought together, and one half body 5° A patch plate 25 is applied to the surface 17b of the outer flange 17 of a, and fixing tools 23 such as screws are inserted into the through holes 24 provided through the outer flange 17 to attach the half bodies 5a, 5a.
are fixed to each other to form a single body. Then, the overlapping branch grooves 16 and 16 form a branch pipe portion IO.

In this embodiment, the fixing device 23 uses a screw 23a and a nut 23b, and the naso l-23b is embedded in the through hole 24 of the other half body 5a.

Next, as shown in FIG. 1, the connector 35 is inserted into the open end 52 of the branch pipe section 10 via the retaining mechanism N, and has an insertion hole 53 through which the branch fiber F is inserted. The distal end 54 is connected to the proximal end 55 of the branched fiber protection tube 36.
The branched fiber protection tube 36 is attached to the case body 5.

That is, the connector 35 is made of a cylindrical body having an outer flange-like convex portion 34 at its base end, and the convex portion 34 fits into a concave groove 57 formed on the inner circumferential surface 56 of the open end of the branch pipe portion 10. The branch pipe portion 10 is fitted in the opening end portion 52 of the branch pipe portion 10 so as not to come out from the open end portion 52 thereof. In other words, in this case, the uneven portions 57.34 constitute a retaining mechanism. In addition, the convex portion 34
A seal ring 58 such as an O-ring is attached to the.

As shown in FIG. 7, the protection tube 36 is a flexible metal tube (that is, a metal spiral tube), and if it is pulled in the longitudinal direction, the inner diameter will be reduced, and if it is compressed, the inner diameter will be reduced. will expand. That is, this protection tube 36 has one end bent in the inner radial direction, the distal end thereof folded back in the axial direction to form a hook-shaped fitting portion 62, and the other end side further bent in the outer radial direction. It is also formed by combining a short tube 64 whose distal end side is folded back in the axial direction to form a hook-shaped fitting portion 63.

Therefore, if the protective tube 36 in the contracted state is inserted into the tip of the connector 35 and the protective tube 36 is pulled, the protective tube 36
The inner diameter of the protective tube 36 is reduced and the protective tube 36 is fixed to the connector 35. Note that it is also preferable that the protective tube 36 is further coated with a coating layer made of a flexible synthetic resin or the like.

Further, at both ends of the case body 5, there are insertion holes 2 through which the covered ends 2a of the sheath 2 of the cable 5 are inserted and removably inserted.
Caps 8 and 8 each having a diameter of 8 are housed inside. That is, as shown in FIG.
A concave circumferential groove 50 and a tapered surface 29 corresponding to the tapered surfaces 13 and 13 and 14 are formed, and a tapered surface 30 is also formed on the proximal end side. Further, in this embodiment, the camp 8 is formed by combining the half bodies 8a, 8a, and is set so that the sheath 2 can be easily inserted into the insertion hole 26. In this case, it is preferable to use an integral cap 8 with a slit so that the insertion hole 28 expands, instead of using the cap 8 as a pair of half halves 8a, 8a. When forming a portion, it is preferable to form it in a straight line shape or in a bias shape.

Then, the coated ends 2a, 2a of the sheath 2 of the optical fiber cable 4 are inserted into the cap 8.8 configured as described above, and the caps 8.8 are inserted into the ends 6, 7 of the case body 5, respectively. The half bodies 5a, 5a are put together so that the half bodies 5a are installed internally.

5a is integrally formed as described above, and the tightening bands 9.9 are fitted into the concave circumferential grooves 11.12 of the case body 5, respectively,
When the tightening bands 9, 9 are tightened, the inner circumferential surface 27 of the case body 5 and the outer circumferential surface 2 of the cap 8 are tightened at both ends 6.7.
6, and the inner peripheral surface 32 of the cap 8 and the outer peripheral surface 33 of the covered end 2a of the sheath 2 are in close contact with each other, and the case body 5 connects the sheath 2 at a predetermined portion (branch) of the cable 4.
The coated end portion 2a of.

It is attached to the cable 4 so as to cover the optical fiber unit 3 exposed from the optical fiber unit 2a. In addition, in this case, a protective tube 3 is provided at the tip of the open end of the branch pipe portion IO.
A connecting tool 35 into which the connecting tool 6 is inserted and fixed is installed inside, and the connecting tool 3
The branch fiber F is inserted into the protective tube 36 through the five insertion holes 53 .

Further, as shown in FIG. 4, the optical fiber unit 3 used in the example includes a coating layer 39, a tensile member 40 included in the coating layer 39, and six optical fiber core wires 48.
It consists of... In this case, of course, the optical fiber core 48 can be freely removed.

Thus, the nine-branch structure 1 configured as described above is configured so that, for example, as shown in FIGS. It is used when branching the fiber unit 3. That is, in this case, the dimension A between the wall surface 37 and the cable 4 is extremely small, but if this structure 1 is used, it can be easily installed as described above, and the dimension A is small. I don't care if it is.

Moreover, FIG. 8 sequentially shows how to branch the optical fiber unit 3 when using this branching part structure 1. First, as shown in FIG. The optical fiber unit 3 is exposed from the optical fiber unit 3, and further, as shown in FIG. And then, the 8th
As shown in Figure 3, the optical fiber unit 3 to be branched is cut at a separate part, the unit 3 is pulled out from a predetermined part, and in this state, the branch part structure 1 is attached to the predetermined part, and A structure 42 having the same structure as the branch part structure 1 except that the case body 41 does not include the branch pipe part 10 is attached to the separated part, and the branching work is completed.

Therefore, according to the embodiment described above, the coated end 2 of the sheath 2
a, the cap with 2a inserted into the insertion hole 28,
The optical fiber unit 3 can be easily installed in both ends 6 and 7 of the case body 5, and the optical fiber unit 3 can be connected to the branch pipe part 1.
0, and by tightening the band 9, both ends 6 and 7 of the case body 5 are completely sealed, making the branching work extremely simple. This branch structure 1 has excellent drip-proof and waterproof properties. Furthermore, since the base end of the branch groove 16 is curved, the optical fiber unit 3 guided out of the case body 5 from the branch pipe part 10 is not bent sharply. The unit 3 will not be damaged. The radius of curvature of the curved portion 51 is set to be greater than or equal to the allowable bending radius of the unit 3 so that the unit 3 does not bend beyond the allowable bending radius. In addition, since the grooves 11.12 are formed in the ends 6, 7, the bands 9, 9 do not come off the ends 6, 7 when tightened, and furthermore, the outer peripheral surface of the cap 8.8 26 and the inner circumferential surfaces 27 of the end portions 6 and 7 have corresponding irregularities, so that the cap 8.
8 will not come off from the case body 5.

Therefore, as shown in FIG.
A seal ring tape 61 such as PvC tape or butyl rubber tape is wound around the outer circumferential surface of the open end 52 of the protective tube 36 or the outer circumferential surface of the proximal end 55 of the protective tube 36 exposed from the open end 52. Open end 52 of branch pipe section 10 to protection tube 36
It is also preferable to seal the proximal end of the tube.

Further, FIG. 12 shows another embodiment of the retaining mechanism N, in which the retaining mechanism N includes a concave groove 59 formed at the base end of the connector 35 and a branch pipe of the case body 5. The convex portion 60 is formed on the inner circumferential surface 56 of the open end of the portion 10 and fits into the groove 59 .

Next, FIG. 13 shows another embodiment of the case body 5, in which case body 5 is not divisible but expandable. That is, the corresponding outer flanges IT, 17 of the half bodies 5a, 5a are connected to form a hinge portion 43. Further, a concave groove 44 is formed on one side of the hinge portion 43, and a convex portion 45 is formed on the other side. Groove 4
4 is fitted.

Therefore, this case body 5 can be expanded as shown by the arrows X and Y, and like the splittable one in the above-mentioned embodiment, the covered end 2a of the sheath 2 can be easily attached to both ends 6.7 of the case body.
, 2a inserted into the insertion hole 28.
can be easily installed.

Therefore, if this case body 5 is used, the hinge part 4
3, it is not necessary to fix the fixing device 23 as in the above-mentioned embodiment, so it is particularly suitable when the dimension A between the wall surface 37 and the cable 4 is extremely small as shown in FIGS. 9 and 10. Become something.

Note that the present invention is not limited to the illustrated embodiment, and the design may be changed without departing from the gist of the present invention. For example, in FIGS. 1 and 12, as shown in FIG. It is also preferable to wrap a seal ring tape 61 around the open end 52 of the tube section 10 to the proximal end of the protective tube 36.
In FIG. 2, it is also preferable to interpose a seal ring 58 between the convex portion 60 and the concave groove 59.

It is also preferable that the ends 6 and 7 of the case body 5 are straight, and that the outer circumferential surface of the cap 8 installed in the ends 6 and 7 is straight.
A pair of lips are formed on the outer circumferential surface of the end portion 6.7, and a concave circumferential groove 11.12 into which the band 9 is fitted is formed for tightening. Further, an uneven portion is formed on the inner circumferential surface 27 of the end portions 6 and 7 to make it difficult for the cap 8 to come off from the case body 5, and a labyrinth groove and an uneven strip are formed on the inner circumferential surface 32 of the character 8. It is also possible to prevent the cap 8 from coming off the sheath 2. In addition, the backing plate 25 is divided into two halves 5a,
It is also free to contact the surface 17b of the outer flange 17 of 5a. It is preferable that the cap 8 is made of an elastic material such as rubber or synthetic resin.Although in the illustrated example, the number of branched fibers F is one, it is of course possible to use two or more branched fibers. Furthermore, in the illustrated example, an optical fiber cable 4 in which an optical fiber unit 3 is housed within the sheath 2 is used. It is also preferable to use existing ones. Furthermore, the protection tube 36 may be formed of a long cylinder made of flexible synthetic resin, rubber, etc., without using a metal flexible tube. It is also preferable to bond the protective tube 36 and the connector 35 together.

〔Effect of the invention〕

In the optical fiber cable branch structure of the present invention, since the branch fiber protection tube 36 is attached, the branch fiber F is always protected from the outside and will not be damaged. The branched fiber protection tube 36 can be reliably held in the case body 5 without slipping out from the open end 52.

[Brief explanation of the drawing]

Fig. 1 is an enlarged sectional view of main parts showing one embodiment of the present invention;
The figure is a side view of the case body in a separated state, Figure 3 is a perspective view of the cap, Figure 4 is an enlarged sectional view of the optical fiber unit,
Fig. 5 is a side view, Fig. 6 is a rear view, Fig. 7 is an enlarged sectional view of the branched fiber protection tube, Fig. 8 is a simplified diagram explaining the branching method in sequence, and Fig. 9 is a diagram of this branching structure. 10 is a front view of the same, FIG. 11 is an enlarged cross-sectional view showing another embodiment of the retaining mechanism, and FIG. 12 is a still another embodiment of the retaining mechanism. Enlarged sectional view, 13th
The figure is a sectional view showing another embodiment of the case body. 2... Sheath, 2a... Covered end, 3... Optical fiber unit, 4... Optical fiber cable, 5...
Case body, lO...branch pipe part, 28...insertion hole,
35... Connector, 36... Protective tube, 48... Optical fiber core wire, 52... Open end, F... Branch fiber, N... Removal prevention mechanism. Patent applicant Mitsubishi Cable Industries, Ltd. Figure 1 Crab j4 'O,j 'j,? Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 9 Figure 10 Figure 13 ζ '30 Figure 11 Figure 12

Claims (1)

[Claims] 1. Branching of an optical fiber cable having a plurality of coated optical fibers or optical fiber units inside the sheath to branch out the coated optical fibers or optical fiber units to the outside of the sheath. A part structure that covers a coated optical fiber or an optical fiber unit exposed from the coated end of the sheath at a predetermined portion of the cable, and a branched fiber of the coated optical fiber or the optical fiber unit. a case main body having a branch pipe portion for guiding the fiber to the outside; and an insertion hole that is installed inside the open end of the branch pipe portion of the case main body via a retaining mechanism and through which the branch fiber is inserted; A branch part structure for an optical fiber cable, comprising: a connector whose distal end is inserted into a proximal end of the branched fiber protection tube to attach the branched fiber protection tube to the case body. 2. The retaining mechanism includes a groove formed on the inner circumferential surface of the opening end of the branch pipe portion of the case body, and a convex portion formed at the proximal end of the connector and fitting into the groove. An optical fiber cable branching structure according to claim 1, comprising the following. 3. The retaining mechanism includes a concave groove formed at the proximal end of the connector, and a convex portion formed on the inner circumferential surface of the open end of the branch pipe portion of the case body and fitting into the concave groove. An optical fiber cable branching structure according to claim 1, comprising the following.