JP2608792B2 - Twisting prevention method when processing excess length of optical fiber connection part - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for preventing twisting of an optical fiber connection portion during extra length processing, and relates to a method of winding an extra length portion around a storage case for storage. Effective to prevent the twisting of the optical fiber that occurs, eliminate the optical transmission loss of the extra length due to this twist, and prevent the rebound of the wound extra length due to the twist. Is.

[Prior Art and Problem] Conventionally, when laying an optical fiber, the work of connecting the optical fiber core wire is always required. In this operation, the coating tube (or protection tube) of the optical fiber cord is removed to expose a predetermined length of the optical fiber core wire, and the ends of the cores are butted and welded together. In this case, due to connection failure, welding connection is repeated several times in an extreme case. For this purpose, the exposed length of the optical fiber (the length obtained by cutting off the coating tube) is generally set to about 1 meter. After the connection is completed, the exposed remaining optical fibers are stored in the storage case and held by the storage case. To store in this storage case, the extra length (the rest of both optical fibers connected to each other, which is about 1 meter on each side in most cases, 2 meters in total) is rolled into a case and stored. This is performed by the procedure of closing and sealing the lid of {see FIG. 6 (A), (B), (C)}.

When the wire is wound in a tuna shape, the wire is always twisted, and the twist increases as the number of windings increases.

If you make a loop of the first roll {Fig. 6 (B)}, A,
The optical fiber A, which rises at the intersection of the two optical fibers B, is always twisted and twisted even number of times. The lower optical fiber B is not twisted in the first loop, but twists every time it is wound an odd number of times.

1 is the most commonly used storage case
A meter optical fiber is wound three times. In this case, the twist of the optical fiber reaches a non-negligible level, causing an optical transmission loss in this extra length, and since the optical fiber is hardly elastically deformed by the twist, the wound ring is The workability of popping up from the case, storing in the storage case, and closing the lid is significantly hindered.

According to the present invention, irrespective of the length of the optical fiber, the optical fiber is wound in a storage case in a storage case in a state where the optical fiber is not twisted, and the winding and storing operations for that purpose are compared. The task is to make it easier to achieve the goal.

[Means for Solving the Problems] Means taken for solving the above problems are configured by the following elements (a) to (f).

(A) The left side of the left and right optical fibers is coiled leftward by n (positive number) times to form a coiled loop.

(B) The right side of the left and right optical fibers is wound in the right direction n + 1 times to the right to form a coil ring.

(C) After connecting the left and right optical fibers to each other, twist the extra length of both optical fibers to the left (180 degrees), and stack the right optical fiber on the left optical fiber. To make one large loop by crossing both optical fibers.

(D) After the above (c), the large loop is reversed to the front, and then one loop of the right optical fiber is unwound, or one loop of the right optical fiber is unrolled and the above Flip the large wheel forward.

(E) Reversing the large wheel to fix the rear joint to the storage case, and (f) feeding the extra length into the coiled wheel to expand each wheel.

[Operation] The left and right optical fibers are wound in a coil shape so as not to leave a twist in the opposite direction to each other to form a coil-shaped ring n + 1 times and n times. Butt and fit the remaining parts so that no twist occurs. Then, the joint is gripped and twisted to the left (180 degrees). At this time, the right optical fiber overlaps and intersects with the left optical fiber to form one large ring. Grip the connection and flip the large loop forward, then unwind the right fiber optic loop. The coil is twisted once because the right-handed loop is unwound, and this cancels out the twisting caused by the above-mentioned twisting and reversing, so that the twisting of the extra length is completely eliminated as a whole. The same is true even if one wheel is unwound at the stage before turning forward. Since the coiled part has zero twist, when the extra length is sent to the left and right wheels and this ring is expanded, all the rings become large 2 × n winding rings that are not twisted at all. Become.

As is apparent from the above operation, the winding directions of the left and right optical fibers need to be opposite to each other, but it is not always essential to wind the right optical fiber rightward. If the right optical fiber is to be wound to the left, the "twisting" of the element (c) may be reversed to the right.

Therefore, "right" and "left" in this specification are
It does not mean literally right and left, but means one and the other on the left and right, respectively.

[Example] The storage case that is generally adopted has a length of one roll.
If the connection operation that can accommodate a loop having a size in the range of 210 mm to 370 mm is successful in one cycle, the extra length of one optical fiber is 1 m, so it is necessary to make three loops of approximately 333 mm in length.
Therefore, the number of turns n of the optical fiber is three. Each time the connection operation fails, the tip of the optical fiber is cut off by 35 mm and shortened. If the connection work fails 10 times, the surplus length of each optical fiber becomes 650 mm, so it is necessary to make three rings with a length of 216 mm or two rings with a length of 325 mm. The selection of the total number of turns is the same as in the prior art.

Prior to the connection, each optical fiber must be wound and held n and n + 1 times, respectively. An embodiment therefor will be described.

The jig for winding each optical fiber may be any jig as long as it has a mechanism and a structure that allows the bundle of optical fibers wound n or n + 1 times to be easily and easily removed from the jig.

One practical example is shown in FIG. In this embodiment, a cylindrical fiber core 13, 13, a partition disk 12, and a holding disk 15 are fixed to a center of a disk-shaped pedestal 11 by a core rod 14. 16 is a knob.

After the left optical fiber is wound leftward around the core 13 of the partition disk 12 of the jig 10 in the left direction n times, the partition disk 12 and the receiving base 11 are wound.
Then, a plate-shaped optical fiber stopper is press-fitted and inserted, and the wound optical fiber is fixed to the jig. Then, after the right optical fiber is wound n + 1 times to the right, an optical fiber stopper is press-fitted and inserted between the partition disk 12 and the pressing disk 15, and the wound optical fiber is used as a jig. Fix for.

After joining the optical fibers to each other, remove the optical fiber stopper, send the extra length of the left and right optical fibers toward the jig, and expand the loop wound around the core, the ring is The diameter is larger than that of the partition disk 12 and the presser disk 15, and the jig 10
Get out of.

The simplest of the optical fiber winding jigs is
A coil spring 21 as shown can be used.

The optical fiber f is sandwiched between the coil rings 22, 22 of the coille spring 21 which is relatively densely wound, and wound spirally n times or n + 1 times, and an appropriate clip,
Alternatively, the optical fiber f is temporarily fixed to the coil spring 21 with an adhesive tape or the like. Wrap the left and right optical fibers,
After connecting both ends to each other, the temporary stop is removed, and the optical fiber loop is removed from the coil spring 21.

FIGS. 3 and 4 show another example in which the work of temporarily fixing the optical fiber loop to the jig and the work of removing the same can be performed simply and easily. In this device, a substrate 31 and a cylindrical fiber winding core 32 are integrated, and a lower end of a fiber pressing lever 34 is inserted into left and right cutouts 33 of the substrate 31 and is pivotally attached to the substrate by a pin 35. An elastic tongue piece 36 is provided in the notch 33 so as to project radially outward from the lower end of the winding core 32. The upper surface of this elastic tongue piece 36 presses the flat surface of the lower end of the fiber pressing lever 34 to make the fiber pressing lever 34 Hold it in the upright position. When the fiber holding lever 34 is tilted left and right against the elasticity of the tongue piece 36, the elastic tongue piece 36 comes into contact with the outer surface of the lever 34 to hold the lever in a horizontal state.

The ring of the fiber wound n or n + 1 times around the outer circumference of the fiber core 32 is pressed by the inner side surface of the fiber pressing lever 34 and held by the core. By providing a large number of V-shaped grooves 37 on the inner surface of the lever 34, the holding by the pressing lever 34 with respect to the optical fiber can be further ensured.

Finally, an example of an actual work procedure for carrying out the present invention using the jig shown in FIG. 1 will be described with reference to FIG.

The distal end of the protective tube of the optical fiber cable 2, 2 'is fixed to the conventional storage case 1 (or storage tray) (A in FIG. 5), and the left tape fiber 3' is mounted in the storage case. It is wound around the core between the pedestal of the tool 10 and the partition disk in a left-handed manner three times (when the remaining length is about 1 m), and the ring is fixed to the jig 10 by the optical fiber stopper 4 '(5th (See FIG. B). Thereafter, the right-hand tape fiber 3 is wound four times clockwise around the core between the partitioning disc and the holding disc, and is fixed by the fiber stopper 4 (C in FIG. 5).
reference).

Then, both ends of the left and right tape fibers are joined in the same manner as the conventional one (see D in FIG. 5). The connecting part 6 is gripped and twisted 180 degrees counterclockwise. At this time, the tape fiber 3 on the right side overlaps and crosses over the tape fiber 3'on the left side, and one large loop R is formed (see E in FIG. 5).
The connecting portion of both tape fibers is gripped and the ring R is inverted forward (see F in FIG. 5), and the connecting portion 6 is press-fitted into the locking clip 5 of the storage case 1 to be fixed. At this time, the large loop R formed by the left and right tape fibers is turned forward and the front and back are reversed, so that one small twisted ring r is formed. This small twisted ring r (see F in FIG. 5) is shifted to the right. Formed on the other tape fiber 3.

Thereafter, a stopper 4 'for the left tape fiber 3'
And remove the extra length of tape fiber 3'on the left side with jig 10
Then, the tape fiber 3'is fed into the inside to expand the diameter of the loop of the tape fiber 3 '(see G in FIG. 5). Further, the stopper 4 of the tape fiber 3 is removed, and one loop of the tape fiber 3 is removed from the jig. As a result, the small twist ring r of the tape fiber 3 is unraveled and disappears (see H in FIG. 5). Thereafter, the extra length of the tape fiber 3 is fed into the jig 10 to expand the loop.

The left and right tape fibers are wound around the jig without twisting, and the twisting of the extra length after being wound on the jig has been eliminated as described above, so there is a large number without twisting as a whole A large ring of is formed. After expanding the above wheel, jig
10 is removed from the storage case.

When using the jig shown in FIG. 1, stabilize the jig 10 outside the storage case, wrap the left and right tape fibers around the jig 10, and fix it with the fiber stoppers 4 and 4 '. A method of moving the jig 10 into the storage tray may be adopted.

When the jigs shown in FIGS. 3 and 4 are adopted, either the right or left tape fiber may be wound around one jig, but both the right and left tape fibers may be wound around one jig. It may be turned. In either case, it is easier to work by winding outside the storage case, expanding the ring, expanding the ring to a predetermined size, and moving the ring into the storage case.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of the jig of the present invention, FIG. 2 is a plan view showing another example of the jig, and FIGS. 3 and 4 are cross-sectional views showing still another example of the jig. FIG. 5 is a plan view, FIG. 5 is an explanatory view of an embodiment of the present invention, and FIGS. 6A to 6C are explanatory views of a conventional technique. In the figure, 1 ... storage case, 2 2 '... optical fiber cable, 3 3' ... tape fiber, 4 4 '... optical fiber stopper, 5 ... locking clip, 6 ... connection Part, 10
…… Jig, 11 …… Catch, 12 …… Partition disc, 13 …… Fiber core, 14 …… Core rod, 15 …… Presser disc, 16 …… Knob, 21 …… Coil spring, 22 …… Coil ring, 31
…… Substrate, 32 …… Fiber core, 33 …… Notch, 34…
… Fiber holding lever, 35… pin, 36 …… elastic tongue,
37 ... V single groove, R ... large ring, r ... twist ring, A,
B, f ... Optical fiber.

Claims (2)

(57) [Claims] 1. One of the left and right optical fibers is n.
+1 turn to wind the coil in one direction to make a loop, and the other optical fiber to turn the coil in the other direction n times to make a loop, and after connecting the left and right optical fibers to each other, the extra length of both optical fibers Is twisted in the other direction, one optical fiber is superimposed on the other optical fiber and crossed to form one large loop, and one loop of one optical fiber is unwound to form a loop of the left and right optical fibers. After equalizing the number, the large one ring is turned forward, or the large one is turned upside down and one ring of the other optical fiber is unwound to remove the number of left and right optical fiber rings. And fixing the connecting portion to the storage case and feeding the extra length portions to the coil-shaped rings to expand the rings, thereby preventing twisting at the time of the extra length processing of the optical fiber connection portion. A jig comprising a receiving portion, a partition plate, a holding plate, a core between the receiving portion and the partition plate, and a winding core between the partition plate and the holding plate; 2. The twist preventing method according to claim 1, wherein the left and right optical fibers are wound around the core.