JPH10142431A - Housing box for optical fiber and housing method of excess length - Google Patents

Abstract

PROBLEM TO BE SOLVED: To compactly collect excess length of an optical fiber by bending and laminating them and further to enable restraining a bent state of the excess length by superposing the excess length bent in circular or ecliptical shape via intgrmediate twist. SOLUTION: A housing box 3 of the optical fiber is constituted by providing a box main body 9 having a lid 8 capable of opening and closing and a protective cover 4 which is housed in the box main body 9 and protects and houses the excess length 10. A hole 11 for inserting the optical fiber 6 and a clasping means 12 for clamping both ends of the excess length 10 at the time of bending the excess length 10 are installed at the box main body 9. By using th housing box 3 of the optical fiber, housing workability is improved. Further, the excess length 10 is compactly housed and housing amount of the excess length can be increased by superposing annular parts formed by twisting the excess length 10 to each other and housing the parts in a protective cover 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber storage box and an extra length storage method.

[0002]

2. Description of the Related Art For example, in a so-called "pull-through type" closure for storing an optical fiber drawn from an optical cable without cutting it, conventionally, an extra length secured in the middle of the drawn optical fiber is made elliptical. It is curved and stored in a dedicated optical fiber storage box. The optical fiber storage box is generally made of metal and has a lid that can be opened and closed. By closing the lid, the stored extra length is protected.

[0003]

However, in the case of the optical fiber storage box as described above, (1) hooking on a protrusion in the box, (2) The optical fiber is likely to jump out of the box,
(3) When the number of optical fibers to be stored is large or the storage length is long, the above (1) and (2) become more remarkable, and the storage workability is improved. Is reduced.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problem, and can maintain and protect a stored optical fiber in a curved state, and can efficiently store and take out the optical fiber even when the excess storage amount is large. It is an object of the present invention to provide an optical fiber storage box and an extra length storage method that can be used.

[0005]

The present invention has the following features to attain the object mentioned above. That is, according to the first aspect of the present invention, an optical fiber storage box for storing a surplus length secured in the middle of an optical fiber, the box main body having an openable and closable lid, and stored in the box main body, A protective cover for protecting and storing the extra length is provided. The box body is provided with an optical fiber insertion hole, and a clamp means for clamping both ends of the extra length when the extra length is bent. An optical fiber storage box characterized in that the above-mentioned problem is solved.

According to the present invention, the extra length of the optical fiber is double-protected and stored by the box body and the protective cover. By storing the optical fiber inside the protective cover, the optical fiber can be protected and stored without damaging the optical fiber irrespective of the structure and inner surface shape in the box body. When storing the optical fiber, the optical fiber is bent using the clamp means.
Further, the clamping means is used for clamping the optical fiber even after the optical fiber is stored, thereby preventing the stored optical fiber from being pinched when the lid is closed. The mounting position of the clamping means may be either inside or outside the box body. The protective cover is preferably formed of a soft synthetic resin or the like, which enables stable storage for a long time without affecting the optical characteristics of the optical fiber. It is preferable that the clamping means is disposed near the optical fiber insertion hole. This makes it easier to bend the optical fiber and avoids interference with the extra length of the optical fiber stored in the box body.

According to a second aspect of the present invention, the protective cover has a tubular portion which can be taken out of the box main body and surrounds the stored extra length from outside to maintain a curved state. The optical fiber storage box described in 1 is a means for solving the above problem.

According to the present invention, the optical fiber is moved together with the protective cover into and out of the box body when the optical fiber is stored and taken out. Even if the protective cover containing the extra length is taken out of the box main body, the curved state of the extra length is maintained, so that the extra length can be moved without dispersing the extra length. Even when the protective cover is stored in the box main body, the cylindrical portion surrounds the extra length and maintains the extra long curved state, thereby preventing the optical fiber from jumping out of the box main body.

According to the third aspect of the present invention, the first step of bending the extra length secured in the middle of the optical fiber drawn from the optical cable terminal into a circle or an ellipse, and opposing the extra length made into the circle or the ellipse. A second step of forming a plurality of annular portions by relatively twisting both sides to form a figure 8, and a third step of overlapping the annular portions with each other and storing them in an optical fiber storage box. An extra length storage method characterized by comprising the above is provided as a means for solving the above problem.

[0010] According to the present invention, the excess length of the optical fiber is curved to form a multi-layered structure, so that the optical fiber is compacted. Moreover, by superimposing the extra length curved in a circle or an ellipse on the way via a twist, the curved state of the extra length can be restrained. Twisting in the second step is performed by simply making the surplus length of a circle or an ellipse into an eight-shape to form two annular portions.
This includes forming a plurality of annular portions into a continuous chain.
When there are three or more annular portions, in the third step, these annular portions are overlapped so as to be substantially coaxial.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. 1 (a) and 1 (b) and FIGS. 2 (a) and 2 (b), reference numeral 1 denotes a closure sleeve, 2 denotes a connecting rod, 3 denotes an optical fiber storage box, 4 denotes a protective cover, and 5 denotes an optical cable. is there. Axial direction (FIG. 1 (a), FIG. 2 (a) left and right direction) inside the closure sleeve 1.
The optical cables 5 are drawn in from both ends, and the multi-core or single-core optical fibers 6 drawn out from the end of each optical cable 5 are stored. A large number of optical fibers 6 are drawn from each optical cable 5, and most of these optical fibers 6 are
The closure sleeve 1 is laid without being cut midway between the optical cables 5, 5 facing each other in the axial direction.

The connecting rod 2 is disposed along the axial direction of the closure sleeve 1, and the optical fiber storage box 3 is placed on the connecting rod 2 (the upper side in FIGS. 1A and 1B). Further, on the upper side of the optical fiber storage box 3, a plurality of trays 7 for storing an optical connection portion for connecting a part of the optical fibers 6 drawn into the closure sleeve 1 and a tray 7 for storing an extra connection length are arranged. It is. As shown in FIGS. 1 (b) and 2 (a) and 2 (b), the trays 7 are rotatable by hinges 7a about an axis parallel to the central axis of the closure sleeve 1 while maintaining the stacked state. Has become.

Hereinafter, the optical fiber storage box 3 will be described with reference to FIGS.
This will be described with reference to FIG. As shown in FIGS. 3 and 4, the optical fiber storage box 3 includes a box main body 9 having an openable lid 8 at an upper portion, and a surplus length stored in the box main body 9 and secured in the middle of the optical fiber 6. And a protective cover 4 that protects and stores 10.

The lid 8 has a handle 8a protruding therefrom. The box body 9 has a rectangular parallelepiped shape, an optical fiber insertion hole 11 opened at both ends in the longitudinal direction, and a clamping means 1 for clamping both ends of the extra length 10 when the extra length 10 is curved.
2 is provided. The optical fiber insertion hole 11 is
Since the groove is recessed from the upper edge 9a, the open state is maintained even when the lid 8 is closed. A free bush (not shown) for protecting the optical fiber 6 inserted into the optical fiber insertion hole 11 is mounted on the entire circumference of the optical fiber insertion hole 11.

The clamping means 12 is a band made of a flexible material such as a resin, and is disposed opposite to both longitudinal ends of the box body 9 and is fixed on the bottom plate 13 of the box body 9. As shown in FIG. 5, each band 12 is installed near the optical fiber insertion hole 11 and
A plurality of optical fibers 6 inserted from 1 into the box body 9 are bound. The binding of the optical fiber 6 by the band 12 can be easily released by operating the hook 12a of the band 12. In addition, the clamp means 12 is not limited to a band,
Other configurations can be applied as long as a plurality of optical fibers 6 can be bound.

As shown in FIG. 6, the protective cover 4 is formed by assembling a belt-like body made of synthetic resin such as plastic or other flexible material into a rectangular tube.
It can be taken out of the box body 9. The protective cover 4 has an outer dimension slightly smaller than the inner surface shape of the box body 9, and is formed with an engaging projection 14 and an engaging hole 15 at both ends in the longitudinal direction of the original band-shaped body. is there. FIG.
2B, the engaging projections 14 and the engaging holes 15 are located above the protective cover 4. When the cover 8 is opened, the protective cover 4 can be engaged without removing the protective cover 4 from the box body 9. De-operation is possible. The protective cover 4 surrounds the stored extra length 10 from the outside by engaging the engagement protrusion 14 with the engagement hole 15. In addition, the protective cover 4 also serves as the cylindrical portion according to the second aspect.

Next, the extra length storing method of the present invention will be described with reference to FIGS. FIG. 7 is a view showing a first step of this extra length storage method, in which the extra length 10 secured in the middle of the optical fiber 6 drawn from the terminal of the optical cable 5 is curved in a circle or an ellipse. The optical fibers 6 housed in the protective cover 4 are assembled and inserted into the box main body 9 from the optical fiber insertion hole 11, and both ends of a portion to be bent into a circle or an ellipse (a surplus length of 10) are clamped by the clamping means 12. Clamp with Thereby, both end positions of the extra length 10 to be bent are stabilized, and workability can be improved.

The optical fiber 6 is inserted into the optical fiber insertion hole 11 because the optical fiber insertion hole 11 has a groove shape recessed from the upper edge 9 a of the box body 9. The optical fiber insertion hole 11 from above the box body 9.
It is done simply by pushing it in.

FIG. 8 is a view showing the second step, in which the opposite sides (upper and lower sides in FIG. 8) of the surplus length 10 formed into a circle or an ellipse are twisted once to form a figure of eight. This forms two annular portions 16,16. At this time, since both ends of the extra length 10 are clamped and fixed by the clamp means 12,
When the extra length 10 is twisted, rotation of the portion of the optical fiber 6 other than the extra length 10 is restricted, and the workability is improved. If the length of the extra length 10 is large, twisting is performed twice or more to connect three or more annular portions 16 in a chain.

FIG. 9 is a diagram showing the third step,
The two annular portions 16, 16 having a surplus length of 10 are superimposed on each other. This allows the extra length 10 to be compacted, so that the extra length storage amount of the optical fiber storage box 3 (in particular, the number of optical fiber cores) can be increased. The surplus length 10 in which the overlapping of the two annular portions 16 and 16 is completed is stored in the protective cover 4 while maintaining the state. On this occasion,
By taking out the protective cover 4 from the box body 9, the operability of storage is improved. When the number of the annular portions 16 formed in the second step is three or more, the annular portions 16 are alternately bent in opposite directions and are superposed on the same axis.

When the storage of the extra length 10 in the protective cover 4 is completed, the engagement protrusion 14 and the engagement hole 15 are engaged to
0 is restrained, and the protective cover 4 is stored in the box body 9. This prevents the bent state of the extra length 10 from being released during the operation of storing the optical fiber 6 in the optical fiber storage box 3, and there is no concern that the optical fiber 6 will be pinched when the lid 8 is closed. .

When pulling out the target optical fiber 6 from the optical fiber 6 stored in the optical fiber storage box 3, the lid 8
Is released, the protective cover 4 is taken out while the extra length 10 is stored, and the extra length 10 is taken out of the protective cover 4 outside the box body 9. Then, the first to third steps are reversed to take out the target optical fiber 6 and separate it out of the optical fiber storage box 3. At this time, since the optical fiber insertion hole 11 has a groove shape depressed from the upper edge 9a of the box body 9, when the target optical fiber 6 is selected from the bundle of optical fibers 6, the optical fiber 6 is pulled up. Just can be separated. The other optical fibers 6 are stored again in the optical fiber storage box 3 through the first to third steps.

Therefore, according to the optical fiber storage box and the extra length storing method of the present embodiment, the optical fiber 6 is protected by the protective cover 4 and stored in the optical fiber storage box 3. The maintenance of the bending radius and the prevention of contact with the corners of the components in the optical fiber storage box 3 are ensured, and the optical characteristics of the optical fiber 6 can be stably maintained for a long time. As a result, the maintenance interval and the life of the optical path are extended. In particular, when applied to an aerial closure, the vibration of the optical fiber 6 is suppressed by the clamp means 5 and the extra length 10 is reliably protected in the protective cover 4 even if vibrations due to wind or the like are repeatedly given. ,
The effect on the optical characteristics can be greatly reduced.

Further, the annular portions 16 formed by twisting the optical fibers 6 are overlapped with each other by the above-mentioned extra length storing method, and are compacted and stored in the protective cover 4. Since the curved state is less likely to collapse due to the restraint, the stability of the stored state is improved, and the maintenance of the optical characteristics of the optical fiber 6 can be further ensured.

The shapes and sizes of the protective cover 4 and the box body 9 are not limited to the present embodiment, but can be changed as appropriate. Further, the optical fiber storage box and extra length storage method of the present invention can be applied to various optical fiber storage cases other than closures, and can be used alone.

[0026]

As described above, according to the optical fiber storage box of the first aspect, the optical fiber stored in the box main body is protected and stored inside the protective cover stored in the box main body. Regardless of the inner structure and inner surface shape, the optical fiber can be stored safely without damaging it,
Even when stored for a long period of time, the optical characteristics can be stably maintained. In addition, when the optical fiber is stored, the optical fiber is fixed and bent using the clamping means, so that the bending workability is improved and the storage time is shortened. .

According to the optical fiber storage box of the present invention, the protective cover can be taken out from the box main body, and has the cylindrical portion that surrounds the stored extra length from the outside and maintains the curved state. (1) By moving the optical fiber together with the protective cover into and out of the box main body when storing and removing the optical fiber, the extra length is restrained even if the protective cover containing the extra length is taken out of the box main body. (2) Due to the restraint of the extra length, there is no fear of inconvenience such as pinching of an optical fiber at the time of the storing operation, and the operability of storing is improved. Due to the length constraint, there is no risk of stress concentration on the specific optical fiber due to the movement of the optical fiber after the storage is completed or contact with parts in the box body, and the optical characteristics of the optical fiber are reliably maintained even after long storage. Do DOO can, excellent effects such as.

According to the extra length storing method of the third aspect, the extra length secured in the middle of the optical fiber drawn from the optical cable terminal is curved into a circle or an ellipse, and the annular portions formed by twisting are overlapped. By matching, (1) the extra length can be compacted and the extra length storage amount of the optical fiber storage box increases, and (2) the curved state of the extra length can be restrained, so that after storage, In addition, there is no fear of stress concentration on a specific optical fiber or contact with components in the box body, and an excellent effect that the optical characteristics of the optical fiber can be reliably maintained even when stored for a long time.

[Brief description of the drawings]

1A and 1B are diagrams showing an embodiment of an optical fiber storage box of the present invention, wherein FIG. 1A is a front view, and FIG. 1B is a cross-sectional view taken along line AA of FIG. 1A.

FIGS. 2A and 2B are views showing an open state of the optical fiber storage box of FIG. 1, wherein FIG. 2A is a plan view and FIG.
FIG. 3 is a sectional view taken along line B of FIG.

FIG. 3 is an overall perspective view showing the optical fiber storage box of FIG. 1;

FIG. 4 is a side view showing the optical fiber storage box of FIG. 1;

FIG. 5 is an enlarged front view showing a clamp means applied to the optical fiber storage box of FIG. 1;

FIG. 6 is a perspective view illustrating a protective cover applied to the optical fiber storage box of FIG. 1;

FIG. 7 is a plan view illustrating a first step, showing a method of storing extra length according to the present invention.

FIG. 8 is a plan view showing a second step, showing the extra-length storing method of the present invention.

FIG. 9 is a plan view showing a third step, showing the extra length storing method of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 3 ... Optical fiber storage box, 4 ... Protective cover, 5 ... Optical cable, 6 ... Optical fiber, 8 ... Lid, 9 ... Box body, 10 ... Extra length, 11 ... Optical fiber insertion hole, 12 ... Clamping means, 1
6 ... an annular part.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hideo Hirao 1440 Mutsuzaki, Sakura City, Chiba Prefecture Inside Fujikura Sakura Plant

Claims (3)

[Claims] 1. An optical fiber storage box for storing an extra length (10) secured in the middle of an optical fiber (6), wherein the box main body (9) has an openable / closable lid (8); A protective cover (4) that is housed in the main body and protects and stores the extra length. The box body has an optical fiber insertion hole (11), and the extra length when the extra length is curved. An optical fiber storage box (3) provided with a clamping means (12) for clamping both ends. 2. The protective cover according to claim 1, wherein the protective cover has a tubular portion (4) which can be taken out of the box main body and surrounds the stored extra length from the outside to maintain a curved state. Optical fiber storage box. 3. A first step of bending a surplus length secured in the middle of an optical fiber drawn from an optical cable (5) terminal into a circle or an ellipse, and opposing both sides of the circle or the elliptical surplus length. A second step of forming a plurality of annular portions by relatively twisting them into a figure-eight shape, and a third step of overlapping the annular portions with each other by overlapping (16) with each other and storing the annular portions in the optical fiber storage box (3). And an extra length storing method.