JP3492452B2 - Overhead branch connection box and extra length storage method for branch optical cable - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an overhead branch connection box and a method for accommodating an extra length of a branch optical cable.

[0002]

2. Description of the Related Art A branch connection box may be used as a drop point when branching an overhead optical cable to a customer. In this case, it is common practice to give the branched optical cable an extra length. This extra length is for ensuring a work extra length required for branch connection and for adapting the replacement to adapt to changes in the surrounding environment after construction. However, heretofore, there has been no suitable method for processing this extra length.

FIG. 5 is an explanatory diagram of a first conventional example of a method for processing a surplus length of a branched optical cable. In the figure, 1 is an overhead branch connection box, 1a is a box bottom surface, 2 is an overhead optical cable, 10 is a branch optical cable, 30 is a utility pole, and 31 is a retainer. This conventional example is a method of slackening the branch optical cable 10 between the retaining portion 31 and the overhead branch connection box 1.

The overhead branch connection box 1 is installed in the middle of the overhead optical cable 2. The aerial optical cable 2 is a self-supporting optical cable in which an optical cable is suspended on a suspension wire by a supporting tool provided intermittently, or a supporting wire portion. An optical fiber core wire is taken out from the overhead optical cable 2 inside the overhead branch connection box 1 and is connected to the optical fiber core wire of the branch optical cable 10 by mechanical connection or fusion connection with a connector. The plurality of optical fiber core wires accommodated in the overhead optical cable 2 are multiple core wires such as a single core wire and a tape-shaped optical fiber core wire. The branch optical cable 10 is a small-core, small-diameter optical cable, which is, for example, a single-core optical outdoor line, and in order to deal with the problem of mechanical strength deterioration due to loss due to bending and elongation strain, a tensile strength member such as a steel core is used. Have.

Regarding the optical fiber core wires in the overhead optical cable 2 which are not branched and connected, there are cases where they are allowed to pass through the overhead branch connection box 1 as they are, and cases where they are once disconnected and then the disconnected parts are reconnected. . Fictitious branch connection box 1
Inside, a surplus length processing plate having a core holder is provided,
The extra length of the optical fiber required for connection work is stored. The optical fiber core wire on the side of the branch optical cable 10 is separated from the strength member and drawn into the overhead branch connection box 1.

The utility pole 30 is provided with a retaining portion 31, and the branched optical cable 10 pulled out from the box lower surface 1a of the aerial optical cable 1 is temporarily retained by the retaining portion 31 and then dropped to a consumer such as a subscriber's house. Be done. Therefore, a large number of branch optical cables with different amounts of sagging hang down between the utility pole 30 and the overhead branch connection box 1, which is aesthetically problematic and also causes other work performed on the utility pole 30, such as a power line or a CATV. In the construction related to the line, the optical fiber communication in use may be hindered by hooking the branch optical cable 10.

FIG. 6 is an explanatory view of a second conventional example of a method for processing an extra length of a branched optical cable. In the figure, the same parts as those in FIG. 40 is a ring,
41 is a ring attachment. In this conventional example, the lower part of the box 1a
The extra length of the branched optical cable 10 is wound around the ring 40 provided in the.

This aerial branch connection box 1 uses the box body of the connection terminal box for copper cables as it is.
A ring 40 is attached to the. This ring 40
Is a bar-shaped body extending in the width direction of the aerial branch connection box 1, the left and right sides of the bar-shaped body are bent upward, and the ends thereof are attached to the ring attachment member 41. Near both ends in the longitudinal direction of the aerial branch connection box 1. And a total of three are provided in the center.

The excess length can be treated by winding the branched optical cable 10 around a plurality of rings 40 like a copper cable. However, if the worker uses the branch optical cable 10
If it is bent too much when it is wound, the radius of curvature of the branched optical cable 10 becomes too small, which may cause a problem of transmission loss.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and when the extra length of the branch optical cable is stored, the storage amount can be set arbitrarily and the branch optical cable is bent too much. It is an object of the present invention to provide an overhead branch connection box and a method for accommodating an extra length of a branch optical cable that can be easily accommodated without any trouble.

[0011]

In the invention according to claim 1, in an aerial branch connecting box for branching and connecting an aerial optical cable to a branch optical cable, a lower side of the aerial branch connecting box outside the aerial branch connecting box. The extra length storage portion of the branched optical cable is provided in the open portion to be, and the extra length storage portion is characterized in that a pair of members having comb-shaped grooves face each other.

According to a second aspect of the present invention, in the overhead branch connection box according to the first aspect, a member for preventing the branch optical cable stored in the extra length storage portion from coming out in the groove direction of the comb-shaped groove. It is characterized by having.

According to a third aspect of the present invention, in the method for processing the extra length of a branch optical cable, the extra length of the branch optical cable branched and connected from the overhead optical cable is looped, and the overhead branch connection outside the overhead branch connection box. The branch optical cable is pushed between the opposing comb-shaped grooves of a pair of members having comb-shaped grooves provided in the open portion on the lower side of the box, and the branch optical cable is provided between the recesses by the spreading force based on the rigidity of the branch optical cable itself. It is characterized by retaining the extra length of.

[0014]

1 is a perspective view of an embodiment of the present invention. In the figure, the same parts as those in FIG. 3 is an extra length storage part, 3a is an upper comb-shaped groove, 3b is a lower comb-shaped groove, 3c is a coupling part, 4 is a tape, 4
a is a snap button. The extra length storage portion 3 and the tape 4 are attached to the bottom surface 1a of the box. Box bottom 1a
A hole for drawing in the branched optical cable 10 is formed in the, but the illustration is omitted.

The extra length storage section 3 includes a pair of upper comb-shaped grooves 3a,
The lower comb-shaped grooves 3b are opposed to each other, and the central portions of the both are joined and integrated by a joining portion 3c.
The portion having a is fixed to the central portion of the box lower surface 1a with the groove facing downward. The longitudinal direction of the groove is an aerial branch connection box 1
A plurality of grooves are arranged in parallel with each other in the longitudinal direction of the aerial branch connection box 1 in parallel to the width direction of the aerial branch connection box 1 to form comb-shaped grooves. The coupling portion 3c has a flat plate shape and is parallel to the groove. As a specific example of the groove, one groove has a width of 4 mm and a depth of 10 mm.
Then, a plurality of these are provided in parallel. The groove interval between the upper comb-shaped groove 3a and the lower comb-shaped groove 3b is 70 mm.
With this size, depending on the shape of the branch optical cable, 1
There are only two or three branch optical cables in one groove.

On the other hand, the tape 4 is provided near the longitudinal ends of the box lower surface 1a, and hangs down from the vicinity of the left and right ends of the box lower surface 1a in the width direction, and the middle portions of the left and right tapes are snap buttons 4a. It can be attached and removed by. This tape 4 droops when the extra length storage section 3
It is about the middle height between the upper comb-shaped groove 3a and the lower comb-shaped groove 3b.

If the working extra length of the branch optical cable 10 having a small number of cores and a small diameter is looped, the upper comb-shaped groove 3 of the extra length storing portion 3 is formed.
It can be housed between a and the lower comb-shaped groove 3b. Further, by passing the tape 4 across the extra length loop, the extra length loop can be prevented from slipping out of the groove. This storage method will be described with reference to FIGS.

FIG. 2 is an explanatory view of a method of looping the branched optical cable, and FIGS. 2 (A) to 2 (D) are explanatory views for explaining the procedure. Reference numeral 10 is the branch optical cable described in FIG. 5, and description thereof is omitted. In FIG. 2 (A), first, the extra length of the branched optical cable 10 is pulled up, and a lower portion thereof is twisted by half a turn about the vertical direction to form a single loop. When the twisted portion is further folded upward, a double loop state shown in FIG. 2B is obtained. Next, press down from the vertical direction or expand the horizontal direction,
The horizontally long double loop state of (C) is obtained. Further, the central portion is pressed down from above and below, and the central portion is pushed into the space between the upper comb-shaped groove 3a and the lower comb-shaped groove 3b from the side surface of the extra length storage portion 3 shown in FIG.

When the excess length of the branch optical cable 10 is short, the left and right widths of the extra length loop are adjusted so as to be narrowed, or
Push in the extra length storage part 3 with a single loop. Alternatively,
In FIG. 2 (A), it is also possible to move the upper part on the right side to the upper part on the left side and push it into the extra length storage section 3 as a half-loop. However, the larger the number of loops, the more reliable the holding. When the extra length of the branch optical cable 10 is long, adjust so that the left and right widths of the extra length loop are expanded,
The extra length can be processed by increasing the number of loops and making it three or more loops. By such a method, the extra length loop can be arbitrarily adjusted to continuously set the extra length amount.

FIG. 3 is an explanatory view showing a state in which the extra length of the branch optical cable is stored. In the figure, the same parts as those in FIG. 5 and FIG. Since the branched optical cable 10 has a tensile strength body such as a steel core, it has a large bending rigidity, and the rigidity of the branched optical cable 10 itself exerts a spreading force, so that the gap between the upper comb-shaped groove 3a and the lower comb-shaped groove 3b of the extra length storage portion 3 acts. Held in. The bending diameter of the extra length loop is determined by the upper and lower groove intervals of the extra length accommodating portion 3, and is not held at a diameter smaller than the upper and lower groove intervals due to the spreading force of the branch optical cable 10.

There are a plurality of pairs of grooves in the extra length storage section 3,
The branched optical cable 10 is stored in a pair of upper and lower grooves. In the case of the extra length storage section 3 in FIG. 1, since there are 8 pairs of grooves,
Extra length loops for books can be stored independently. Therefore, the extra length loops are stored one by one, and the extra length can be processed without overlapping or entangled with another extra length loop.

When a plurality of branch optical cables 10 are already stored and it is necessary to take out any one of them, the extra length loop of the branch optical cable 10 may be pulled out along the direction of the groove. . When storing the pulled extra length loop again, push it in along the groove, or move the stored extra length loop to the groove at the back one by one and open the outermost groove and put it in this groove. All you have to do is push in the pulled out one.

The extra length storage section 3 may have only one pair of grooves, and in this case also, one branch optical cable 10 can be stored.
On the other hand, when there are a plurality of pairs of grooves, when the number of loops of the branch optical cable 10 increases, the loops may be moved to another groove for each round in order to separate the overlap of the loops.

Further, in the extra length storage portion 1 shown in FIG. 1, a pair of grooves are arranged vertically above and below, but it is also possible to arrange a pair of grooves horizontally. That is, the longitudinal direction of the groove is also the same as the longitudinal direction of the aerial branch connection box 1, but when a plurality of pairs are prepared by providing a pair of grooves near both ends in the width direction of the aerial branch connection box 1, Comb-shaped grooves may be arranged in the vertical direction.

On the other hand, the accommodated loop-shaped branch optical cable 10 may be displaced in the groove direction due to vibration or the like.
In order to prevent the extra length loop from slipping out, a mechanism for limiting the movement may be provided in the extra length loop. Tape 4 is one example.

The snap button 4a of the tape 4 is removed, the tape 4 is laid across the extra length loop, and the snap button 4a is fastened again. In this way, the bottom surface 1a of the box and the tape 4
It is possible to surround the extra length loop with and hold it on the lower surface 1a of the box. The tape 4 may be provided on the right side of the drawing near the end in the longitudinal direction, and the extra length loops may be retained on both sides.

FIG. 4 is an explanatory view of another example of retaining the extra length loop. In the figure, the same parts as those in FIG. 20 is a pin. In this example, a threaded pin insertion hole 3d is provided near the central portion of the coupling portion 3c of the extra length storage portion 3, and the pin 20 is attached thereto.

After accommodating the extra length loop, the horizontal portion of the L-shaped pin 20 is screwed into the pin insertion hole 3d, so that the bent portion of the pin 20 is bent on one side surface of the upper comb groove 3a or the lower comb groove 3b. Abut and fix. As a result, the extra length storing portion 3 and the L-shaped pin 20 cross the extra length loop to surround the extra length loop, so that the extra length loop can be retained and the extra length loop is prevented from slipping out. can do. In the illustrated example, the pin 20 and the pin insertion hole 3d are individually provided on the left and right sides of the coupling portion 3c. It should be noted that instead of fixing with screws, fixing may be performed by fitting, and in this case, the left and right pins 20 can be integrated.

The bent portion of the pin 20 does not necessarily have to be brought into contact with one of the upper comb-shaped groove 3a and the lower comb-shaped groove 3b, and may be spaced or may not have the bent portion. Even in this case, if the pin 20 crosses the extra length loop, the extra length loop can be prevented from slipping out in the groove direction. The pin 20 may be attached from the beginning before accommodating the extra length loop.

The ring 40 and the ring attachment 41 described in the second conventional example described with reference to FIG. 6 can be used instead of the tape 4. Ring 40 is ring fitting 4
It shall be detachably attached to 1. the first,
After the ring 40 is removed and the extra length loop is stored, the ring 40 may be inserted across the extra length loop and then fixed to the ring attachment 41.

In the above description, the center of the extra length loop is pushed into the pair of grooves of the extra length storage part 1, but two extra length storage parts are shortened along the longitudinal direction of the overhead branch connection box 1. Alternatively, the extra length loops may be arranged at predetermined intervals, and the extra length loops may be pushed into the pair of grooves of each extra length storage portion so that the center of the extra length loop is located between the two extra length storage portions. Further, the groove does not necessarily have to have a constant width and a constant depth, and a pair of recesses capable of holding the extra length loop by the spreading force based on the rigidity of the extra length loop itself may be used.

[0032]

As is apparent from the above description, according to the first aspect of the invention, the branch length optical fiber has an extra length storage portion at the lower portion of the box, and the extra length storage portion has a pair of comb-shaped grooves. Since the members of (1) and (2) face each other, it is ensured that the bending diameter of the branched optical cable does not become less than the distance between the pair of grooves of the extra length storage portion, and there is an effect of high reliability. In addition, the length of the extra length loop can be adjusted arbitrarily to easily set the amount of extra length continuously, and a pair of grooves can be used for each branch optical cable, so that there is no excess or entanglement. Has the effect of long processing. For this reason, it is useful when used for accommodating the extra length of the drop-down connection box of the optical subscriber system.

According to the second aspect of the present invention, since the branch optical cable housed in the extra length housing portion has a member for preventing the branch optical cable from slipping out in the groove direction of the comb-shaped groove, the branch optical cable that easily moves in the groove direction vibrates. There is an effect that can be prevented from getting out by such as.

According to the third aspect of the present invention, the extra length of the branch optical cable branched and connected from the overhead optical cable is formed into a loop shape and is pushed between a pair of recesses provided under the overhead branch connection box, Since it is held between the recesses by the spreading force based on its own rigidity, it is ensured that the bending diameter of the branched optical cable does not become less than the distance between the pair of recesses, and there is an effect of high reliability. Moreover, since the length of the extra length loop can be arbitrarily adjusted, there is an effect that the extra length amount can be continuously set and extra length processing can be performed. For this reason, it is useful when used for accommodating the extra length of the drop-down connection box of the optical subscriber system.

[Brief description of drawings]

FIG. 1 is a perspective view of an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a method for looping a branched optical cable, and FIGS. 2 (A) to 2 (D) are explanatory diagrams for explaining the procedure.

FIG. 3 is an explanatory diagram showing a state in which an extra length of the branched optical cable is stored.

FIG. 4 is an explanatory diagram of another example of retaining an extra length loop.

FIG. 5 is an explanatory diagram of a first conventional example of a surplus length processing method for a branched optical cable.

FIG. 6 is an explanatory diagram of a second conventional example of a surplus length processing method for a branched optical cable.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Aerial branch connection box, 2 ... Aerial optical cable, 3 ... Extra length storage part, 4 ... Tape, 10 ... Branch optical cable, 20 ... Pin, 30 ... Utility pole, 31 ... Pull-fastener, 40 ... Ring, 4
1 ... Ring attachment.

Front page continued (72) Inventor Hiroki Ishikawa 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, Ltd. Yokohama In-house (72) Inventor Makoto Tominaga 1300 No. 1 Irita Nitta, Kita Sotoyama, Komaki City, Aichi Japan Communication Electronics Co., Ltd. (56) Reference JP-A-58-40711 (JP, A) Actual 60-120405 (JP, U) Actual development Sho 59-58415 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) G02B 6/00 G02B 6/24

Claims (3)

(57) [Claims] 1. An overhead branch connection box for branching and connecting an overhead optical cable to a branch optical cable, wherein an extra length of the branch optical cable is stored in an open portion below the overhead branch connection box outside the overhead branch connection box. An aerial branch connection box characterized in that a portion is provided, and the extra length storage portion is formed by facing a pair of members having comb-shaped grooves. 2. The aerial branch connection box according to claim 1, further comprising a member for preventing the branch optical cable housed in the extra length housing portion from slipping out in the groove direction of the comb-shaped groove. 3. A branch optical cable branched and connected from the overhead optical cable is formed into a loop length, and a comb-shaped groove is provided outside the overhead branch connection box, which is provided in an open portion below the overhead branch connection box. The extra length of the branched optical cable is characterized in that the extra length of the branched optical cable is held between the comb-shaped grooves by pushing it between the comb-shaped grooves of the pair of members that have it, and the spreading force based on the rigidity of the branch optical cable itself. Processing method.