JPH058565Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an optical fiber cable termination box.

[Conventional technology and its problems]

Generally, the optical fiber itself is made of inorganic glass or the like, and is immune to electromagnetic induction and surges caused by lightning. However, in addition to such inorganic optical fibers and plastic materials, metals are also used as constituent materials for optical fiber cables. In other words, steel wire or steel stranded wire is used for the optical fiber cable tension member, steel wire is used for the unit tension member, and aluminum tape, steel strip, etc. are used for the inner surface of the sheath layer. .

Therefore, at the end of the optical fiber cable,
It can be said that each of the metal components mentioned above must be grounded.

However, in the past, each of the above-mentioned metal components was grounded by a separate ground wire, which caused the problem that the inside of the termination box and its vicinity became complicated and complicated. Furthermore, optical fiber cable clamps, unit tension member clamps, and the like are separately attached inside the conventional termination box, resulting in an even more complicated internal structure.

[Means for solving problems]

In order to solve these conventional problems, the present invention has been developed to bring the cable tension member into a conductive state in a termination box provided at the end of an optical fiber cable that has a cable tension member and an optical fiber unit inside. A metal tension member clamp is provided in the termination box main body to fix the optical fiber unit to the tension member clamp, and the unit tension member of the optical fiber unit is fixed to the tension member clamp in a conductive state, and the optical fiber cable other than the optical fiber cable is A metal component is connected to the tension member clamp in a conductive state, and an inner end thereof is connected to the tension member clamp in a conductive state and extends to the outside of the termination box body, and the other end is connected to the tension member clamp in a conductive state. It is equipped with an earth wire for collective grounding.

[Effect]

The metal tension member clamp inside the termination box fixes not only the cable tension member but also multiple unit tension members at the same time.Moreover, this tension member clamp and the ground wire secure the optical fiber cable. Both of the above-mentioned tension members and metal components such as the presser tape can be grounded all at once.

〔Example〕

Hereinafter, the present invention will be explained in detail based on the illustrated embodiments.

In FIG. 1, 11 is an optical fiber cable 12
This is a short cylindrical terminal box provided at the terminal end 12a of the cable, specifically a moisture-proof dam and a cable-to-connector conversion site.

In FIG. 8, the optical fiber cable 12 has a cable tension member 13 in the center and eight optical fiber units 1 and 2 arranged in a star shape around the cable tension member 13.
. . . 7 and 8, respectively, will be exemplified. Tension member 13 is composed of steel strands 13a and a surrounding plastic coating layer 13b.
14 is a presser tape made of aluminum or the like;
15 is a sheath layer of plastic such as polyethylene, and the star-shaped optical fiber unit 1,
2...Sequentially coat the outside of 7 and 8.

FIG. 10 specifically shows an example of the optical fiber unit 1. That is, a unit tension member 16 made of a steel wire is arranged at the center, and fiber core wires 17 are arranged in a star shape around the unit tension member 16, and a pressure winding tape 19 is wound on top of the unit tension member 16 with an inclusion 18 interposed therebetween. It is configured as follows.

Therefore, as shown in FIG.
consists of a short cylindrical main sleeve 21 made of metal such as aluminum, a plastic cable clamp 22 and a fiber cord holding lid 23 that cover the openings at both ends of the main sleeve 21, and the terminal end of the optical fiber cable 12. The cable clamp 12a is inserted into the hole 22a of the cable clamp 22, and its external vicinity is hermetically covered with a sealing tape 24, a heat-shrinkable tube 25, etc., and is held down by a cap 26 and connected to the cable clamp 22. The main sleeve 21 is integrally connected.

27 is a metal tension member clamp that clamps and fixes the cable tension member 13 in a conductive state, and the coating layer 13b in FIG. 8 is peeled off to expose only a small length range of the steel strands 13a. and pinch it from above and below. Reference numerals 28 and 28 denote a pair of supporting members that hold the clamp 27 inside the terminal box body 20, and as shown in FIG.
Both ends are fixed to the inner surface and the inner surface of the holding lid 23 with screws, etc., and are provided in parallel to the longitudinal direction.

This tension member clamp 27 is constructed by overlapping the lower half body 29 shown in FIG. 4 and the upper half body 30 shown in FIG.
(see figure) etc.).

That is, the lower half body 29 has a substantially rectangular plate shape as shown in FIG. 4, has a V groove 32 in the center of the upper surface, and has screw holes 33 near the four corners.
As shown in Figure 4, there are four setscrew holes 34 on the left and right...
It has... In addition, four unit tension member insertion holes 35 are provided in a direction parallel to the V-groove 32 so as to be perpendicular to the setscrew holes 34, respectively. Further, as shown in FIGS. 4 and 2, the left and right end surfaces 36, 36 have screw holes 38, 38 for screws 37 fixed to the support member 28.
is provided.

As shown in FIG. 5, the upper half 30 has a substantially rectangular plate shape and has a V-groove 39 in the center of the lower surface, and holes 40 for the screws 31 near the four corners.
As shown in FIG. 5, it has four setscrew holes 41. In addition, four unit tension member insertion holes 35 are provided in a direction parallel to the V-groove 39 so as to be perpendicular to the setscrew holes 34, respectively.

By overlapping these two halves 29 and 30, as shown in FIGS. 1, 2, and 3, the steel strands 13a of the cable tension member 13 are
It is clamped and fixed within the grooves 32 and 39. Said screw 3
1... is a fixing means for integrating these halves 29, 30 in a polymeric manner. Then, the unit tension member 16 is inserted into the insertion hole 35, and the set screw 42 is inserted into the set screw hole 41... and the set screw hole 34 (as shown in FIG. 2).
(see figure) and is fixed to prevent it from falling out. That is, unit tension member 16...
is also fixed to this clamp 27 in a conductive state.

Further, as shown in FIG. 1, other metal components such as the metal presser tape 14 shown in FIG. 8 are connected to the clamp 27 via the tape bond wire 43 to make them conductive. In the same figure, the screw 3
1 is also used to fix one end of this tape bond line 43.

In this way, all of the metal members constituting the optical fiber cable 12 are connected together to the tension member clamp 27 in the center, and as shown in FIG. The screw 31 also serves as the tension member clamp 27,
The inner end of the ground wire 44 is connected in a conductive state, and the ground wire 44 is pulled out to the outside and grounded. That is, as shown in FIG. 6 and FIG. A hair ground wire 44 is extended, and the other end of the ground wire 44 (not shown) is grounded. In this way, it can be said that the ground wire 44 is also for collective grounding.

In FIG. 6 and FIG. 1, a center hole 46 through which the cable tension member 13 is inserted is provided in the center of the fiber cord holding lid 23, and the aforementioned hole 45 is provided in the lateral position of the center hole 46. Furthermore, a large number of small holes 47 for inserting fiber cords are arranged in an orderly manner, and FIG. 6 shows an example of 48 small holes 47, and the optical fiber unit 1 shown in FIG. , 2...Applicable to the case where 7 and 8 are each "6 hearts".

In FIG. 1, numerals 48, . . . are fiber core wires, which are exposed inside the termination box main body 20, but extend outside as an optical fiber cord 49. That is, as shown in FIGS. 11 and 12, a fiber core 48 is coated with a nylon tube 50, and reinforcing fibers 51 and a jacket 52 are sequentially coated thereon to form an optical fiber cord 49, which increases rigidity. and gives strength.

Furthermore, a cord clamp 53 as shown in FIGS. 1, 11, and 12 is used to fix the end of the optical fiber cord 49 to the inner surface of the fiber cord holding lid 23.

That is, the cord clamp 53 includes a short cylindrical portion 54 having an axial hole into which one end of the optical fiber cord 49 is inserted, and a flange portion 5 protruding from the outer peripheral surface of the short cylindrical portion 54.
The reinforcing fiber 51 at one end of the optical fiber cord 49 inserted into the cord clamp body 56 is bent (as shown in FIG. 11) and stretched along the top of the short cylindrical portion 54. and a holding outer cylinder 57 that is press-fitted from above (as indicated by arrow K in FIG. 11). The flange portion 55 of the cord clamp 53
the small hole 47 until it comes into contact with the inner surface of the holding lid 23.
A part of the short cylindrical portion 54 is inserted into and fixed.
Note that an optical connector 58 is attached to the tip of each optical fiber cord 49 (as shown in FIG. 1).

It should be noted that the optical fiber cable 12 may be a 24-fiber cable as shown in FIG.
4 optical fiber units 1, 2, 3, 4 and 6
The intervening books Q... are arranged in a star shape.
In this case, the fiber cord holding lid 23 used is the one shown in FIG. 7, which has 24 small holes 47. Of course, the termination box 11 of the present invention can be applied to various optical fiber cables other than those shown in the drawings, and in short, the metal members of the optical fiber cable can be combined into one tension member clamp 27 and one ground It is grounded at line 44.
The clamp 27 is a metal fitting for collectively grounding, and is also a metal fitting for collectively fixing the tension members 13, 16, . . . , and can be said to have both functions.

Note that the inside of the termination box 11 is filled with a compound 59 such as urethane foam.

[Effect of idea]

The present invention is constructed as described above, and has a tension member clamp inside that serves as a bracket for collective grounding and collective fixing, and can significantly reduce the number of parts and simplify it, making it more compact and lightweight. was also achieved. Furthermore, it is possible to perform the fixing work of each tension member 13, 16... and the grounding work of all the metal components of the members constituting the optical fiber cable 12 with extremely high efficiency, ease and reliability. Therefore, it can be said that its practical effects are significant.

[Brief explanation of the drawing]

Fig. 1 is an overall sectional plan view showing an embodiment of the present invention, Fig. 2 is a perspective view of the main part, Fig. 3 is a front view of the main part, and Fig. 4 is a diagram showing a specific example of the lower half. It's hot,
The same figure is a plan view thereof, the same figure is a front view, the same figure is a right side view, and FIG. 5 is a diagram showing a specific example of the upper half; The figure is a bottom view, FIGS. 6 and 7 are front views showing a specific example of a fiber cord holding lid, FIGS. 8 and 9 are cross-sectional explanatory views showing a specific example of an optical fiber cable, and FIG. 11 is an explanatory cross-sectional view of an example of an optical fiber unit, FIG. 11 is an enlarged exploded perspective view of main parts, and FIG.
FIG. 2 is a perspective view showing the assembled state. 1, 2, 3, 4, 5, 6, 7, 8... optical fiber unit, 11... termination box, 12... optical fiber cable, 13... cable tension member, 16... unit tension member, 20...
... Termination box body, 27... Tension member clamp, 12a... Termination.

Claims (1)

[Claims for Utility Model Registration] A metal tension member for fixing the cable tension member in a conductive state in a termination box provided at the end of an optical fiber cable having a cable tension member and an optical fiber unit inside. A clamp is provided in the termination box body, and the unit tension member of the optical fiber unit is fixed to the tension member clamp in a conductive state, and other metal components of the optical fiber cable are fixed to the tension member clamp. An earth wire for collective grounding, which is connected to the member clamp in a conductive state, and whose inner end is connected to the tension member clamp in a conductive state, and which extends to the outside of the termination box body and whose other end is grounded. An optical fiber cable termination box characterized by being attached with.