JPS58142241A - Screening method for optical fiber and device thereof - Google Patents

Abstract

PURPOSE:To perform a more perfect security of strength, by a method wherein a maximum practice is produced at a whole periphery application of a twist moment to an optical fiber. CONSTITUTION:A first motion member 4 is located at an approximately equal distance from two bobbins 1 and 3, and an optical fiber 2 is stretched around the member 4, the optical fiber 2 is pressed against the first motion member 4 with the aid of second motion members 5. If, with this, the two bobbins 1 and 3 are turned, the optical fiber 2 begins to run, it is guided by a guide roller 6a and reaches between the first motion member 4 and the second motion member 5, and since the second motion members 5 reciprocate in a manner to press the optical fiber 2 against the first motion member 4, the optical fiber 2 moves over the rotation over the first motion member 4. The optical fiber 2 is located in an O-position when the second motion members 5 are brought to a neutral state, and it is situated in an A-position or a B-position when the second motion members 5 are brought to an upper dead point of a reciprocating movement. The optical fiber 2 turns at least one time during a period for which it reaches the A- position or the B-position from the O-position, and a maximum shearing stress is exerted at the A-position or the B-position.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical fiber screening method and apparatus for inspecting the strength of the optical fiber along its longitudinal direction.

When screening optical fibers, it is common to apply a certain tension to the optical fiber in its longitudinal direction and test its strength or strain.

As a typical example, the apparatus shown in FIG. 1 can be mentioned. 5. As can be seen from the figure, the optical fiber C running between a pair of rolls a% b is given tension by tension reels d and e placed in the middle.

The disadvantage of this device is that the optical fiber C is connected to the tension reel d,
Excessive from e! There is a risk of damage to the coating layer due to the slippage that may occur between the two.

As a conventional example other than the above, there is a device shown in FIG. This is a device in which a large number of mandrels f... are arranged and an optical fiber g is wound around each mandrel so that the optical fiber g is bent in several directions.

The disadvantages of this device are that it is complicated due to the large number of mandrels required, and that no matter how many mandrels are used, it is not possible to generate the maximum bending stress around the entire circumference of the optical fiber. be.

The present invention aims to solve the above-mentioned problems by applying a torsional moment to the optical fiber to be tested to generate maximum stress around the entire circumference, and this will be explained with reference to an embodiment shown in the drawings. , in Figure 3 (1
) is the horizontally fed bobbin on which the optical fiber (2) is wound, (3
) is a winding bobbin for winding the optical fiber (2), (4
) is an optical fiber (2) running between both bobbins (tl) (3).
) a first actuating member formed by a mandrel, (5)
is a second actuating member made of a roller or the like that reciprocates along the longitudinal direction of the mandrel. The optical fiber (2) is placed at a position equidistant from the bobbin (11) [3), and the optical fiber (2) is wound around the same member (4). 2) is pressed by the first actuating member (4) with an appropriate pressing force.

As mentioned above, a mandrel is used as the first actuating member (4),
When using a roller as the second actuating member (5),
These are made to be freely rotatable around the axis.

When both bobbins (11 (3)) are rotated in such a state, the optical fiber (2) starts running between them, and the optical fiber (2) coming out from the supply bobbin 11) passes through the guide roller (6).
& guided by the first actuating member (4) and the second actuating member (5)
reach between.

The second actuating member (5) reciprocates while pressing the optical fiber (2) against the first actuating member (4).
) is 1! as shown in Figure 4. : It will roll on the first actuating member (4).

In the figure, the 0 position of the optical fiber (2) is the position when the second second actuating member (5) is at the top dead center of the reciprocating process, and the optical fiber (2) is moved from the 0 position to the A or B position. It moves at least one revolution until reaching , and experiences maximum shear stress at position A or B.

The optical fiber (2), which has been given a torsional moment as described above, comes out from between the first and second actuating members [4] [5), is guided by the guide roller (6) b, and is guided by the winding drum (
3) is wound up.

As mentioned above, when a roller is used as the second actuating member (5), one pair of rollers is used as shown in the drawing, but it may be one pair or three or more, and the number may be determined as appropriate. Ru.

Alternatively, an endless band may be wound around a pair of rollers.

Furthermore, the outer diameter of the mandrel used as the first actuating member (4) can be arbitrarily selected within a range that can give the necessary amount of strain to the optical fiber (2). A mandrel is used as the first actuating member (4), and a passive member such as a roller that reciprocates along the mandrel is used as the second actuating member (5) to cause the second actuating member (5) to reciprocate. The first actuating member (4) may be reciprocated.

In other words, the relative positions of the first and second actuating members +41+51 may be changed so as to impart a twisting moment to the optical fiber (2).

Further, in the above embodiment, the optical fiber (2) is running, but the first and second actuating members (4 cylinders) may be running.

namely the optical fiber (2) and the first and second actuating members (4).
It is only necessary that the relative position with (5) changes.

Also, when a torsion moment is applied to the optical fiber (2), “
From this point of view, 2. The optical fiber may be sandwiched between the plate-like members of Te, and the relative position of both members may be changed in a direction intersecting the longitudinal direction of the optical fiber.

Although the supply bobbin (1) is used in FIG. 3, the optical fiber may be directly supplied from an optical fiber drawing machine or a secondary coating extruder without using this.

As described above, in the present invention, the test is performed by applying a twisting moment to the optical fiber, so that the entire circumference of the optical fiber receives the maximum stress, and therefore, the strength is more completely guaranteed.

In addition, when applying a twisting moment to the optical fiber, the optical fiber is held between the first and second actuating members and their relative positions are changed, so the tension applied in the longitudinal direction of the optical fiber is reduced compared to the conventional example. Therefore, when tension is applied, the coating layer is not crushed and deteriorated, or the unevenness of the tension-applying roller etc. damages the surface of the glass (1).

Particularly in the case of large-diameter optical fibers, a considerable amount of tension must be applied in the conventional example, which is extremely advantageous.

There is also the advantage that the number of parts is reduced, resulting in a simpler device structure.

[Brief explanation of drawings]

1 and 2 are schematic diagrams showing a conventional device; FIG. 3 is a schematic front view of a device according to the present invention; and FIG. 4 is an explanatory diagram when a torsion moment is applied to an optical fiber. (2)...0.Optical fiber (4)...0 First operating member (5)...Second operating member Patent applicant representative Patent attorney Makoto Ito Procedural amendment 1. Display of case: Japanese Patent Application No. 57-253942, title of invention: Optical fiber screening method and device 3
, Relationship to the case of the person making the amendment Patent Applicant: Furukawa Electric Co., Ltd. 4, Agent: 100 Contents of amendments to each column of "Brief Description of Drawings" (1) The scope of the claims has been amended as follows. Mas0r
t) A screening method for optical fibers in which the strength is inspected along the length of the optical fiber, the method comprising bending the original fiber to generate maximum stress over its entire circumference. (2) The method for screening optical fibers according to claim 1, which comprises: (1) applying a frictional force to the running optical fiber in a direction perpendicular to its longitudinal direction to cause the optical fiber to bend. (3) In a device that performs strength inspection along the longitudinal direction of an optical fiber, a predetermined pressing force [with which the source fiber is movably held and the relative position changes back and forth in a direction intersecting the longitudinal direction of the optical fiber] is used. 1. An optical fiber screening device, comprising first and second actuating members whose relative positions with respect to the optical fiber vary in the longitudinal direction of the optical fiber. (4) The device for screening an original fiber according to claim 3, wherein the second actuating member moves back and forth in a direction perpendicular to the longitudinal direction of the original fiber while being older than the first actuating member. (5) The first actuating member is a mandrel that is rotatable around its axis, and the second actuating member is disposed around the outer periphery of the mandrel and reciprocates along the longitudinal direction of the mandrel while rotating the mandrel. A reciprocating member rotatable in the same direction as the reciprocating member, wherein the optical fiber is wound around the mandrel and is pressed against the mandrel by the reciprocating member so as to be freely movable. The optical fiber screening device according to item 3 or 4. (6) The optical fiber screening device according to claim 51, wherein the reciprocating member is a roller disposed around the outer periphery of the mandrel. (2) "Torsional moment" on page 4, lines 10 to 11 of the specification is corrected to "bending." (3) "Second operating member 15) on page 5, line 16" is corrected to read, "The two second operating members (5) have the same forward movement direction and the same backward movement direction." Correct "reciprocating motion" in line 17 of the page to "synchronously reciprocating motion in directions A and B in Figure 4". Therefore, the optical fiber (2) will receive the maximum stress due to bending from each point on its circumference.'' He corrected the ``twisting moment'' in line 7 of the same page to ``bending.'' 1 Ding. (5) Correct “so as to give a bending moment” to “so as to roll” on page 7, lines 7-8,
Delete lines 15-19 on the same page. (6) "Torsional moment" on page 8, line 5 of the same page is changed to "
"Bending" and corrected it as "Strength Guarantee" r "Strength Guarantee" on the 7th line of the same page, and "1 torsion moment" on the 9th line of the same page as "
"bending" and correct it. (7) "Torsional moment" on page 9, line 6.
"bending" and correct it.

Claims (1)

[Scope of Claims] 11) A screening method for optical fibers in which the strength is inspected along the length of the optical fiber, the method comprising applying a twisting moment to the optical fiber to generate maximum stress over its entire circumference. (2) The method for screening optical fibers according to claim 1, characterized in that a frictional force is applied to the running optical fiber in a direction orthogonal to its longitudinal direction to cause the optical fiber to twist. (3) In a device that inspects the strength of an optical fiber along its longitudinal direction, the optical fiber is movably clamped with a predetermined pressing force, and the relative position changes back and forth in a direction intersecting the longitudinal direction of the optical fiber. An optical fiber screening device comprising first and second actuating members whose relative positions with respect to the fiber change in the longitudinal direction of the optical fiber. (4) The optical fiber screening device according to claim 3, wherein the second actuating member reciprocates along the first actuating member in a direction perpendicular to the longitudinal direction of the optical fiber. (5) The first actuating member is a mandrel rotatable about its axis, and the second actuating member is disposed around the outer periphery of the mandrel and reciprocates along the longitudinal direction of the mandrel and in the rotational direction of the mandrel. A reciprocating member rotatable in the same direction as the reciprocating member, the optical fiber being wound around the mandrel and being pressed against the mandrel by the reciprocating member so as to be freely movable. A screening device for an Ω optical fiber according to item 3 or 4. (6) The optical fiber screening device according to claim 5, wherein the reciprocating member is a row 2 disposed around the outer periphery of the mandrel.