JPH04101105A - Method for preventing twisting of optical fiber connection part in surplus length processing - Google Patents

Abstract

PURPOSE:To facilitate winding and housing operation for optical fibers by winding the right and left optical fibers spirally while the tips of the optical fibers are held free, connecting the optical fiber tips by a fusion splicing connecting machine, and then expanding the loops of the optical fibers and cutting a connecting part in part of the loops. CONSTITUTION:Many U-shaped unipack grip parts 7 are provided on the outer peripheral surface of a unipack support base and unipacks 6 are inserted into the unipack grip parts 7 and fixed. The surplus-length part of an optical fiber 2 is looped to form a proper number of loops 10, which are inserted into a unipack 6 and then held in the unipack 6 by closing the opening end of the unipack 6. The tips 11 of the optical fiber while led out of the loops 10 are mounted on the fusion splicing connecting machine 12 and connected. After the fusion splicing connection, the loops 10 are expanded to put the free ends of the optical fiber in the loops 10. Consequently, the surplus-length part of the optical fiber is prevented from twisting and the housing operation for the surplus-length part in a housing case is made easy and simple.

Description

[Detailed Description of the Invention] [Field of Application in the M Industry] This invention relates to a method for preventing twisting when processing excess length of an optical fiber connection portion, which occurs when the excess length is wound and stored in a storage case. It is effective when used to prevent twisting of the optical fiber, eliminate optical transmission loss in the excess length due to this twist, and prevent rebound of the excess length after one turn due to twisting. .

[Prior Art and Problems] Conventionally, when installing an optical fiber cable, the work of connecting the optical fibers is always involved.In this work, the cable sheath and the optical fiber sheathing tube (or protective tube) provided as necessary are required. The optical fibers are removed to expose a certain length of optical fibers (including single-core fibers or tape fibers, the same applies hereinafter), and then the coating layer at the tips of the optical fibers is removed, the fibers are exposed, and the fibers are welded and connected to each other. In this case, if the connection fails, in extreme cases the welding connection will have to be repeated several times. For this purpose, the exposed length of the optical fiber (the length after removing the cable sheath and covering tube) is generally set to about 1 meter. After the connection is completed, store this exposed remaining optical fiber in a storage case and hold it with the storage case.The work of storing it in this storage case is done with a lot of effort since it is the remaining part of both optical fibers that are connected to each other. In the case of 1 meter on each side, 2 meters in total) is coiled and stored in a case, and the case is closed and sealed (Figure 8 (A),
(See (B) and (C)).

When a wire is wound into a coil, the wire is always twisted, and the twist increases as the number of turns increases.

When making the first loop (Fig. 8 (B)), A, 8
The optical fiber A placed above at the intersection of both optical fibers will always be twisted, and will be twisted at an even number of times. The lower optical fiber B is not twisted in the first loop, but is twisted every odd number of turns.

In the storage case commonly used today, one meter of optical fiber is wound three times. In this case, the twist of the optical fiber reaches a level that cannot be ignored, resulting in optical transmission loss in this extra length.

In addition, since the optical fiber hardly deforms elastically when twisted, the wound ring springs up from the case, significantly impeding the workability of storing the optical fiber in the storage case and closing the lid.

The present invention is applicable regardless of the size of the extra length of the optical fiber.

The object of the present invention is to store the optical fiber in a coiled state in a storage case without twisting the fiber, and to make the storage process relatively easy. .

Measures taken to solve the CS problem] The measures taken to solve the above problem are constituted by the following elements (a) to (d).

(b) Attach the U-shaped Unipack to the Unipack support stand and attach it removably.

(b) Wrap the optical fiber into a coil and have the Unipack grip the loop.

(c) After welding and connecting the free ends of the left and right optical fibers, the ring inside the Unipack is expanded, and then the Unipack is removed from the Unipack support.

(d) The ring of optical fiber held in the Unipack,
Store it in the extra length storage case along with the Unipack.

Note that the above-mentioned "Unipack" is a U-shaped holder whose tip opening is closed by a simple engagement means such as a snap engagement.

[Operation: The optical fiber is wound into a coil shape with the tips of the left and right optical fibers being straight, and this is held in a U-shaped unipack, so by winding the optical fiber into a coil shape, twisting force is applied to the optical fiber. has no effect. After the tips of the optical fibers are connected using a welding splicer, the optical fiber loop is enlarged, the spliced part is taken into a part of the loop, and the entire loop is held by the Uni-Pack.Next, the Uni-Pack is removed from the support stand and left as it is. Since the zero wheel stored in the storage case with extra length is held in the storage case by the Uni-Pack, there is no bounce of the ring, and there is no need to fix the optical fiber ring to the storage case, and the storage case has no extra length. It is sufficient if it functions simply as a cover to protect the long portion.

Therefore, since the storage case may be a simple storage container such as a plastic bag, it is extremely easy to store the extra length of the looped optical fiber in the storage case.

[Example] Fig. 1 shows a conventionally known optical fiber connection part, and the flange 1 shown in Fig. 1 is for fixing the tip of the optical fiber cable 2 and fixing both ends of the connection surface. The left and right flanges 1.1 are connected to each other by a connection $3.

The extra length 4 of the optical fiber connection is approximately 80a! It has a length of 1.

At the center of the connecting rod 3 is an arc-shaped Unipack support 5, which is removably attached (see Figures 2 and 3), and a number of U-shaped Unipacks 6 are attached to the outer peripheral surface of this Unipack support 5. are doing.

A large number of U-shaped unipack gripping parts 7 are provided on the outer peripheral surface of the unipack support base, and the unipack 6 is inserted into these unipack gripping parts 7 and fixed. The Unipack is installed with the open end facing radially outward. A groove 6a with a C-shaped cross section and a C-shaped protrusion 6b are formed on the inner surface of the opening end of this Unipack.
The open end of the Unipack 6 is closed by snap-engaging the C-shaped protrusion 6b to the C-shaped #6a.

Wind the extra length of the optical fiber into a coil shape and make an appropriate number of loops.
0 is made, this loop 10 is inserted into the Unipack 6, the open end of the Unipack 6 is closed, and the Unipack 6 holds the optical fiber loop. With the tip 11 of the optical fiber pulled out of the ring 10, it is attached to the welding splicer 12 and the two tips are connected (see FIGS. 4 and 5). After welding and splicing, the loop 10 is expanded so that the free end of the optical fiber is absorbed into the loop 10.

At this time, the ring tries to expand due to the elasticity of the optical fiber, but is held down by the Unipack and becomes a horizontally elongated oval (see Fig. 6).

Next, the Unipack 6 is removed from the Unipack gripping part 7, and the remaining length is stored in a storage case 13 such as a plastic bag (see FIG. 7), with the ring still being held by the Unipack.

The storage case 13 is supported by the support arm 3' of the connecting rod 3.

After the extra lengths of all the optical fibers are stored in respective storage cases and the connection work is completed, the Unipack support stand 5 is removed from the connecting rod 3.

[Effects of the Invention] The above-mentioned problem of the present invention is novel. Therefore, by solving the above-mentioned problems and preventing twisting of the excess length of the optical fiber,
The unique effect of the present invention is that the work of storing the extra length into the storage case is extremely simple and easy. Although it is not publicly known, there is an invention that prevents the extra length from twisting by devising a way to make the loop, and a jig is attached to the storage tray, the extra length is wrapped around this jig, and the free end is welded. An invention has also been completed in which the jig is removed after connection, the extra length of the ring is stored in a storage tray, and the ring is fixed and held in the storage tray (@pending application).

The present invention utilizes Unipack to create a ring and hold it,
Since the ring is stored in the storage case with the ring held by the Unipack, the work of storing it in the storage case is easier than in the above-mentioned inventions, and the storage case does not need to be a so-called tray. A simple storage container such as a plastic bag can be used as the case. This is one of the major advantages of the present invention. Furthermore, since a soft bag can be used as a storage case, when a large number of soft bags are stacked and stored in the connection surface (protection box for the connection part), there is no need for complicated support means such as a storage shelf (the return case is If the tray is a tray, a storage shelf is required), and the above storage task can be completed by suspending a number of storage cases (bags) from a simple rod. This is also a great advantage of the present invention.

[Brief explanation of the drawing]

Figure 1 is a perspective view of the internal structure of a conventional optical fiber connection surface, Figure 2 is a perspective view of an embodiment of the present invention, and Figure 2-1 is a perspective view of the internal structure of a conventional optical fiber connection surface.
A partially enlarged view of the figure, FIG. 3 is a front view and side view of the Unipack support stand in FIG. 2, FIGS. 4, 5, 6 and 7 are explanatory diagrams of the optical fiber connection work procedure, FIG. 8 is an explanatory drawing of the prior art. In the figure: 1...Flange, 2...Optical fiber cable, 3...Connecting rod, 3'...Support arm of connecting rod 3, 4...Excess connecting length of optical fiber, 5...・Arc-shaped Unipack support stand, 6... U-shaped Unipack, 6a...
・Groove with C-shaped cross section, 6b...C-shaped protrusion, 7...U
Holding part of type Unipack, 10... ring, 11... tip of optical fiber, 12... welding splicer, 13... storage case, A, B... optical fiber.

Claims (1)

[Claims] Attach the U-shaped Unipack to the Unipack support stand, removably attach it, wind the optical fiber into a coil, have the Unipack grip the loop, weld and connect the free ends of the left and right optical fibers, and then insert it into the Unipack. expand the optical fiber ring,
After that, the Unipack is removed from the Unipack support base, and the optical fiber loop held by the Unipack is stored in an extra length storage case together with the Unipack, which is a method for preventing twisting when processing excess length of an optical fiber connection part.