JPH10268139A - Removal tool for optical fiber conductor cover and cover removal method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To dispense with the adjustment of a cover retaining force and make easy a cover removal work. SOLUTION: This tool 1 has a pair of retaining members 2 and 3, a plurality of dividing blades 16 for cutting an optical fiber conductor cover from the radial external side, a slide mechanism 13 for connecting the retaining members 2 and 3 to each other, so as to be capable of freely nearing and parting, a presser means 32 for pressing the cover to the internal surface of the retaining members 2 and 3 through a travel under a frictional force with the cover during the nearing and parting motions of the members 2 and 3. In this case, an optical fiber conductor is held with the retaining members 2 and 3, and the cover thereof is cut with the dividing blades 16, so as to separate the members 2 and 3 from each other, thereby easily removing the cover without damaging the internal surface thereof. In particular, the cover is held under an optimum retaining force with the presser means 32 concurrently with the separation of the retaining members 2 and 3. Thus, the adjustment of the retaining force is not needed, thereby making a cover removal work easy.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tool and a method for removing a coating of an optical fiber.

[0002]

2. Description of the Related Art In the field of communication, optical fibers capable of high-speed and large-capacity transmission have become the mainstream of transmission lines, and most of middle- and long-distance trunk lines have already been replaced by optical fiber cables from conventional metal cables. Further, in a few years, efforts to realize an optical subscriber transmission system in which a line to each home is to be converted to an optical fiber are being progressed at a rapid pace.

[0003] Most of the medium- and long-distance trunk lines already laid are taped by aligning a plurality of optical fibers.
A so-called optical fiber tape is assembled into a cable. In optical subscriber transmission systems,
Similar cables are likely to be used from the office to the vicinity of each home.

On the other hand, in the optical subscriber transmission system, one optical fiber laid to each home is sufficient in terms of transmission capacity. Therefore, in the portion where the optical fiber is drawn down from the multi-core optical fiber cable to each subscriber, it is necessary to connect the multi-core tape fiber and the single-core optical fiber.

[0005] Fusion splicing, connectors, mechanical splices and the like are used to connect the multi-core tape fiber to the single-core optical fiber, but none of them can directly connect the multi-core and single-core optical fibers. For this reason, a method has been devised which uses a multi-core-to-single-core conversion optical fiber in which one end is a multi-core optical fiber tape and the other end is a single-core optical fiber. This method
Since it is only necessary to connect multi-core tape fibers and single-core optical fibers, construction is easy.

[0006] However, although the structure of the tape fiber is determined by the number of core wires, the single core wire includes a φ0.25 mm core wire or a φ0.9 mm nylon core wire coated with an ultraviolet curable resin. Considering the connection with these, it is necessary to prepare a multi-core / single-core conversion core having a single core of φ0.25 mm and φ0.9 mm, which is not economical. Also, it is not possible to connect different core diameters to one multi-core / single-core conversion core.

Therefore, the present inventors have previously removed a part of the nylon coating layer and the silicone layer of an optical fiber core having a silicone coating layer and a nylon coating layer formed on the outer periphery of an ultraviolet curable resin coating layer having a diameter of 0.25 mm. A multi-core to single-core conversion core formed by exposing an ultraviolet curable resin coating layer of φ0.25 mm and forming a tape was devised. This core wire is a nylon core wire with a single core of φ0.9 mm, but by removing the nylon coating layer and silicone layer, the 0.25 mm ultraviolet curable resin coating layer can be exposed. Can be connected according to the core diameter
It is economical because there is no need to prepare various kinds of multi-core / single-core conversion cores. In addition, different core diameters can be connected to one multi-core / single-core conversion core.

As the single core portion of the conversion core wire, a nylon core wire having a sectional structure as shown in FIG. 11 is employed. As a tool for removing the coating 57 to be removed from the nylon core fiber, that is, the optical fiber core 51 (or the single core part of the conversion core), that is, the nylon coating layer 52 and the silicone layer 53, conventionally, FIG. A structure as shown in FIG. 13 was used.

A conventional coating removing tool a has an optical fiber core 51 sandwiched between members b and c which can be opened and closed like a stapler, and an optical fiber core 5 with a groove d provided in one member b.
The position 1 is guided, the movement is guided, and the cylindrical part f of the nylon coating layer 52 and the silicone layer 53 is cut and removed over the length by a blade e provided on the other member c.

However, in the case of the conventional tool a, since the cutting is performed while the optical fiber 51 is relatively moved with respect to the blade e, the blade e completely cuts the silicone layer 53 during the movement. Φ0.25mm
There is a problem that the ultraviolet curable resin coating layer 54 is damaged.

Also, when removing the nylon coating layer 52 and the silicone layer 53 of the core wire where the ultraviolet curing resin coating layer 54 having a diameter of 0.25 mm has already been partially exposed, the ultraviolet curing resin coating layer 54 is damaged. There was a problem.

Since only the cylindrical portion f of the nylon coating layer 52 and the silicone layer 53 is removed, it is necessary to peel off the remaining nylon coating layer 52 and the silicone layer 53 from the ultraviolet curable resin coating layer 54. However, there was a problem that it took time to work.

Therefore, the present inventors have solved the problems of the prior art, and have developed a tool for removing a sheath of an optical fiber, which can remove the sheath in a short time and does not damage the portion on the inner peripheral side of the sheath. A coating removal method was proposed in Japanese Patent Application No. 8-350606.

As shown in FIGS. 9 and 10, the tool comprises a pair of holding members 2, 3 for holding the optical fiber core 51 at a position close to the longitudinal direction thereof. And a plurality of splitting blades, ie, fixed blades, provided on one holding member 2 for cutting the coating 57 of the held optical fiber core wire 51 from the radial outside. 17 and the movable blade 18, a notch provided in these divided blades for inserting a portion of the optical fiber core wire 51 on the inner peripheral side from the coating 57, and a cutout provided in one holding member 2, And guide portions 29, 29 for guiding the movement of. In particular, the holding members 2 and 3 are composed of base members 4 and 5 and cover members 6 and 7 for opening and closing the base members. The optical fiber core 51 is seated on the groove 10 and the optical fiber 51 is accurately positioned. It has become.

As a method of removing the coating using the coating removing tool, first, as shown in FIG.
The cover members 6 and 7 are opened in a state where they are closest to each other, and the optical fiber core 51 is placed in the groove 10. At this time,
The orientation of the optical fiber 51 is determined by the fixed blade 17 and the movable blade 1.
8, the holding member 2 is defined as a base side, and the other holding member 3 is defined as a tip side. Next, as shown in FIG. 10, the cover members 6 and 7 are closed, and the base members 4 and 5 and the cover members 6 and 7 are manually held to hold the optical fiber core 51. Further, when the pushing portion 24 of the movable blade 18 is pressed in this state, the movable blade 18 descends while being accurately guided by the guide portion 29 toward the fixed blade 17, and cuts the covering 57 together with the fixed blade 17 from above and below. Become. Thereafter, the movable blade 18 is released to return to the original position by the elastic force of the spring 25, and the holding member 2 on the base side is pressed and the holding member 3 on the tip side is pulled, so that the holding member 3 moves away. At the same time, the tip side portion of the coating 57 also comes out neatly from the cut position as shown in FIG.

As described above, since the blades 17 and 18 do not move relative to the optical fiber 51, the cutting of the portion on the inner peripheral side of the coating 57 is completely prevented.

[0017]

In such a conventional tool and method, the base member 4, 5 and the cover member 6, 7 are held by hand to hold the optical fiber core 51. Therefore, there is a problem that it is difficult to adjust the holding force, and it is difficult to remove the coating. That is, if the holding force is weak, the optical fiber core 51 slides in the holding member 3 when the holding member 3 is pulled, so that the coating cannot be removed. There is a problem in that the coating 57 is pressed against the coating layer 54 and it becomes difficult to separate and move the coating 57.

[0018]

SUMMARY OF THE INVENTION The present invention is a tool for removing coating of an optical fiber core having a coating of a predetermined thickness on an outer peripheral portion, wherein the optical fiber core is disposed at a close position along its longitudinal direction. A pair of holding members, a plurality of split blades provided on one of the holding members, for cutting the coating of the held optical fiber core wire from the outside in the radial direction, and the holding member in the core wire longitudinal direction. And a slide mechanism for moving the holding member apart from each other along one of the holding members. When the holding member moves away from the holding member, the holding member moves by frictional force with the coating to move the coating on the inner surface of the holding member. And pressing means for pressing.

The present invention also relates to a method for removing a coating of an optical fiber core having a coating of a predetermined thickness on an outer peripheral portion, wherein the optical fiber core is held in a pair at close positions along a longitudinal direction thereof. Held by a member, the coating of the held optical fiber core wire is cut from a radially outer side by a plurality of divided blades of one of the holding members, and these holding members are separated from each other via a slide mechanism, At the time of separation, the pressing means is moved by frictional force with the coating, and the coating is removed while pressing the coating against the inner surface of the holding member by the pressing means.

In this case, since the pressing means naturally generates an appropriate holding force when the holding member is moved away, the adjustment of the holding force by hand becomes unnecessary, and the coating is easily removed.

Preferably, the pressing means comprises an eccentric cam. Further, the holding member includes a base member on which the optical fiber core is seated and a cover member that covers the base member so that the base member can be opened and closed, and the holding member has a lock mechanism for locking the cover member in a closed state. Is preferred.

[0022]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

First, the structure of the optical fiber to be coated will be described with reference to FIG. This also applies to the single core portion of the multicore-single-core conversion core wire as described above. As shown in the figure, an optical fiber core 51 is formed by coating an ultraviolet curable resin coating layer 54 (hereinafter referred to as U
V coating layer), a silicone layer 53 and a nylon coating layer 52 are sequentially laminated. Especially the UV coating layer 54
Has an outer diameter of D ₁ = 0.25 mm, and the outermost nylon coating layer 52 has an outer diameter of D ₂ = 0.9 mm.
, And the latter defines a large-diameter secondary core wire. Here, the silicone layer 53 and the nylon coating layer 52 form a coating 57 on the outer peripheral side of the optical fiber 51, which is the secondary core, by covering the primary core 56, which is the inner peripheral part thereof. I have. The silicone layer 53 and the nylon coating layer 52 are portions to be removed in the optical fiber core 51, and the thickness thereof is t = (0.9-0.25) /2=0.325 mm. The UV coating layer 54, the silicone layer 53 and the nylon coating layer 52 form primary, secondary and tertiary coating layers, respectively. The glass fiber strand 55 is composed of a core and a clad, and the UV coating layer 54 has a three-layer structure, and the outermost layer has the same color as the nylon coating layer 52 and has a coating 57.
After the elimination is performed, the cord can be identified.

FIG. 1 shows a coating removing tool according to the present invention. As shown in the drawing, the coating removing tool 1 comprises a pair of holding members 2 for holding an optical fiber 51 at a close position along its longitudinal direction. , 3. These holding members 2 and 3
Are base members 4 and 5 on which the optical fiber 51 is seated.
And cover members 6 and 7 rotatably provided on the base members 4 and 5.

The base members 4 and 5 are formed in a rectangular parallelepiped shape or a semicylindrical plate shape extending in one direction, and have a hinge plate (not shown) on the back surface 8 thereof. , 7 can be turned or opened and closed. Each of the base members 4 and 5 has a groove 10 in its upper surface 9 for accommodating and seating the optical fiber 51. The groove 10 is formed linearly along the extension or longitudinal direction of the base members 4 and 5, and has a V-shaped cross section.
The depth of the groove 10 is set so that the upper end thereof projects when the optical fiber core 51 is received (FIG. 7).
reference).

The cover members 6 and 7 are connected to the base members 4 and 5 respectively.
Are arranged side by side in the longitudinal direction, and when closed, cover the upper surface 9 of the base members 4 and 5 and
The optical fiber 51 accommodated in the optical fiber 51 is held therebetween. The lower surface 11 of the cover members 6 and 7
The elastic body 12 that can abut the optical fiber 51 is buried flush with the optical fiber. The elastic body 12 is made of a material such as silicon rubber, and extends in the longitudinal direction at an intermediate position before and after the lower surface 11 of the cover members 6 and 7. The elastic body 12 ensures the holding of the optical fiber core 51 and also prevents the nylon coating layer 52 from being damaged during the holding. Note that the cover members 6 and 7 are integrally provided with flanges 6a and 7a so that the cover members 6 and 7 can be opened by hand.

By the way, the holding members 2 and 3 are so arranged that they can be moved close to and away from each other along the longitudinal direction.
Are linked by That is, the slide mechanism 13 includes a pair of shafts 14 fixed to one base member 5 and a pair of shaft insertion holes 15 provided in the other base member 4. Here, the shaft 14 may have a structure that can be completely removed from the shaft insertion hole 15, and the holding members 2 and 3 may be separated from each other. In this way, the shaft 14 slides in the shaft insertion hole 15 so that the movement of the holding members 2 and 3 toward and away from each other is accurately guided in the longitudinal direction.

Further, the one holding member 2 is provided with a plurality of divided blades 16 for cutting the coating 57 of the optical fiber 51 in the holding state from the outside in the radial direction and from the entire circumferential direction. That is, here, the divided blade 16 includes a fixed blade 17 fixed to the base member 4 and a movable blade 18 provided on the cover member 6 and movable toward the fixed blade 17. The fixed blade 17 covers the cover 5 with its blade portion 19 facing upward.
7 and the movable blade 18 cuts the upper half of the cover 57 with its blade portion 20 facing downward. The fixed blade 17 and the movable blade 18 are formed by processing a metal plate piece, and the plane portion thereof is arranged in the longitudinal direction or perpendicular to the extending direction of the groove 10, and is disposed at the same position along the longitudinal direction. ing.

The fixed blade 17 is inserted and fixed to a pair of guide portions 29 protruding from the base member 4 to the bottom, and the blade portion 19 is raised upward from the inner surface of the groove 10 as shown in FIG. The blade portion 19 has a semicircular notch 19 a at a position along the groove 10 of the blade portion 19. In addition, the movable blade 18 can be moved perpendicularly to the surface direction of the cover member 6 by forming a long hole 22 in the vertical portion 21 and fastening the set screw 23 to the cover member 6 through the long hole 22. ing. In the movable blade 18, a pushing portion 24 continuous with the vertical portion 21 is formed so as to protrude above the cover member 6. Further, the movable blade 18 is urged upward by a spring 25 shown in FIG.

The guide portion 29 is formed in a U-shaped cross section, and the movable blade 18 can be inserted into the remaining portion of the upper end portion to guide the movement. The movable blade 18 is, as shown in FIG.
When it is guided by the guide portion 29 and descends, it eventually hits the fixed blade 17. When this abutment occurs, the semicircular notch 20a formed in the blade portion 20 matches the semicircular notch 20a of the fixed blade 17, and the primary core 56 of the optical fiber 51 is completely inserted. In addition, the circular hole 30 is formed so that the inner peripheral portion of the silicone layer 53 can be inserted.
The contact end between the fixed blade 17 and the movable blade 18 is formed in a straight line, and the rear surface of the cover member 6 on which the movable blade 18 is provided is for preventing interference with the guide portion 29 when the cover member 6 is closed. A step-shaped notch 27 is provided. In particular, the fixed blade 17 and the movable blade 18 are provided at the closest end of one holding member 2 closest to the other holding member 3.

In particular, the base member 4 of one of the holding members 2 is provided with a cam receiving hole 31 in which an eccentric cam 32 serving as a pressing means is received. As shown in FIG. 4, the cam receiving hole 31 is a rectangular hole having a bottom and an upper part opened, and is located just below the cover member 6 which is on the side closer to the other holding member 3 (hereinafter simply referred to as the “closer side”). And has an opening smaller than its cover member 6. And eccentric cam 3
2 is supported rotatably around the pin 33. The pin 33 extends in a direction perpendicular to the longitudinal direction, and is
1, the eccentric cam 32 is disposed on the far side (hereinafter simply referred to as far side) with respect to the holding member 3. A spring 34 as a biasing means is inserted in a compressed state between the side wall on the side close to the cam receiving hole 31 and the eccentric cam 32. This allows the eccentric cam 32 to rotate along the longitudinal direction while being constantly urged to the far side.

The eccentric cam 32 is formed in a fan shape having an angle of about 90 °, and its cam surface 35 faces upward. In particular, the cam surface 35 is formed such that the distance to the pin 33 is smaller on the near side portion than on the far side portion, that is, the eccentric cam 32 is formed with a small diameter on the near side and a large diameter on the far side. As shown in FIG. 4, when the eccentric cam 32 is in the original position on the far side, the cam surface 35 projects slightly upward from the lowermost end of the groove 10 and the optical fiber core seated on the groove 10. It comes into contact with the coating 57 of the wire 51.

As shown in FIG. 1, one of the holding members 2
Is provided with a lock mechanism 36 for locking the close side cover member 6 in a closed state. Lock mechanism 36
Are hook members 37 slidably provided on the cover member 6 and hook members 3 provided on the base member 4.
And a locking hole 38 into which the wire 7 is inserted and locked. The hook member 37 is slidable in the longitudinal direction along the elongated hole 39 of the cover member 6, and a disk-shaped knob 40 for manual operation is formed at the upper end thereof (see FIG. 3), and at the lower end thereof. Has a bent claw portion 41 which forms a substantial locking portion. Another claw portion (not shown) for hooking the claw portion 41 is provided inside the locking hole 38, and the claw portions are hooked to each other to achieve locking of the cover member 6.

Next, a coating removing method using the coating removing tool 1 will be described.

First, as shown in FIG.
They are positioned closest to each other. Then, the cover members 6 and 7 are opened, and the optical fiber 5
Put 1 on. At this time, the direction of the optical fiber 51 is
The holding member 2 where the fixed blade 17 and the movable blade 18 are located is the leading end side on the coating removal side, and the other holding member 3 is the root side. Then, the position of the fixed blade 17 is adjusted to the position where the removal of the coating 57 is to be started. In this state, no cut is made because the optical fiber 51 is merely placed on the fixed blade 17.

Next, as shown in FIG.
Is closed, and the optical fiber core 51 is sandwiched and held at a close position along the longitudinal direction. In particular, in the cover member 6 on the side close to the holding member 2, the hook member 37 is simultaneously closed.
When the hook member 37 is slid toward the near side by operating the knob 40 from above, the locking of the cover member 6 is achieved. . The other cover members 6 and 7 are sandwiched by hand together with the base members 4 and 5 to close the cover members 6 and 7 and hold the optical fiber core 51. At this time, the cut by the fixed blade 17 has not been made yet, and the movable blade 18 is not in contact with the optical fiber 51 because it is pushed by the spring 25 and is at the upper position. At this time, as shown in FIG.
The cam surface 35 on the side closer to
Just to touch.

Further, in this state, the pressing portion 2 of the movable blade 18 is
When 4 is pressed, the movable blade 18 descends while being accurately guided by the guide portion 29 toward the fixed blade 17, and cuts the covering 57 together with the fixed blade 17 from above and below. The pushing of the movable blade 18 is performed until the movable blade 18 comes into contact with the fixed blade 17.
At this time, as shown in FIG.
Has a larger longitudinal width than the outer diameter D ₂ of the groove 10 is precisely position the optical fiber 51, the primary semicircular notch 19a of the double-edged portion 19, 20, 20a may form a circular hole 30 Since the core wire 56 is inserted with a small gap, only the covering 57 is cut accurately from the outside in the radial direction and from the entire circumferential direction.

Thereafter, the movable blade 18 is released to return to the original position by the elastic force of the spring 25, and the holding member 3 on the base side is pressed to pull the holding member 2 on the tip side.

At this time, in the holding member 2 on the distal end side, any cover member 6 should not be pressed too much by hand. This is because an optimal holding force is naturally generated by the action of the eccentric cam 32.

That is, as described above, the cover member 6 is locked, and the portion of the cam surface 35 near the cam surface 35 is in contact with the sheath 57 of the optical fiber 51 as shown in FIG.
When the holding member 2 is pulled in the separating direction in this state, first, the optical fiber core wire 51 slides slightly in the holding member 2 and relatively moves, whereby the eccentric cam 32 is turned to the close side by the frictional force with the coating 57. The optical fiber core 51 is pressed against the elastic body 12 of the lower surface 11 of the cover member 6 (that is, the inner surface of the holding member 2) by the rise of the cam surface 35. That is, with the initial separation movement of the holding member 2, the optical fiber core 51 is gradually sandwiched between the cam surface 35 and the elastic body 12.

Thus, the pinching becomes strong to some extent,
When a predetermined holding force is generated, as shown in FIG.
2 cannot rotate, and if the holding member 2 is continuously pulled thereafter, only the coating 57 is peeled off from the primary core wire 56, and only the coating 57 is separated and removed from the cut position as shown in FIG. Become. And the outer diameter is D ₁
The primary core wire 56 or the UV coating layer 54 can be exposed.

Since the silicone layer 53 in contact with the UV coating layer 54 is soft, the removal of the coating is smoothly performed by deformation and slippage of the silicone layer 53.
When the silicone layer 53 partially remains on the surface of the UV coating layer 54, it can be easily removed by wiping it with gauze impregnated with alcohol or the like.

Here, since the movable blade 18 is raised before the holding member 2 is pulled and there is escape by the stepped notch 27, the optical fiber core immediately after being cut by the fixed blade 17 and the movable blade 18 is used. The wire 51 rises slightly from the fixed blade 17 at the same time as the pulling of the holding member 2, and is substantially released. Therefore, even if the tension is performed in this state, the fixed blade 17 does not come into contact with the primary core wire 56, so that the primary core wire 56 or the UV coating layer 54 is prevented from being damaged.

As described above, in the coating removing tool and the coating removing method, the coating 57 to be removed can be optimally held with the minimum necessary force, thereby reducing the coating removing resistance and adjusting the holding force. The coating removal operation can be made extremely easy as unnecessary. Lock mechanism 3
6, the cover member 6 is locked, so that it is possible to automatically receive a reaction force when the optical fiber core 51 is pressed by raising the cam surface 35, whereby the holding force can be reduced without pressing the cover member 6 by hand. It occurs naturally and the work becomes easier.

The inventor conducted a coating removal test using such a tool and method. As a test method, the coating on the tip side was 50 mm for each of 50 optical fiber cores.
Each sample was removed twice, and a total of 100 mm of coating was removed from one sample. As a result, no harmful damage such as scratching of the UV coating layer was confirmed for any of the samples, thereby confirming the effectiveness of the tool and the method.

Here, the eccentric cam 32 is used as the pressing means in the tool 1, but a tapered member may be used as the pressing means instead. That is, at the same time as the holding member 2 is pulled, the tapered member is moved in the longitudinal direction by the frictional force with the optical fiber 51, and is raised toward the cover member 6 to cover 5
7 can be expected to have the same function and effect as described above. Thus, the form of the pressing means is not particularly limited.

Further, such a pressing means can be provided on the other holding member 3. In this case, the direction and the pulling direction of the optical fiber 51 are reversed, and the holding member 3 is attached to the removal side (the tip side). ) Will be retained. At this time, there is no relative movement between the fixed blade 17 and the movable blade 18 with the primary core wire 56, and the damage is completely prevented. It is also conceivable to provide a plurality of pressing means on one holding member 2, 3 or to provide a pressing means on the cover members 6, 7. Further, it is also conceivable that the holding member is simply cylindrical and the holding is performed only by the pressing means.

Similarly, various configurations of the lock mechanism 36 are conceivable, and it is of course possible to provide this for the other cover members 6 and 7.

On the other hand, in the tool 1, the dividing blade 16 is composed of two fixed blades 17 and movable blades 18. For example, as shown in FIG. 8, four movable blades are arranged at 90 ° intervals in the circumferential direction. The blade 28 may be used. Some of them may be fixed blades, and in other words, whether or not the divided blades can be moved, the number, the shape, the arrangement, and the like are not particularly limited.

Further, when the thickness of the coating and the primary and secondary core diameters are different from each other, the fixed blade 17 and the movable blade 18 may be replaced with ones having different sizes.

Also, such tools and methods can be used to remove tubes from tubed optical fibers. That is,
In the present embodiment, using the inner diameter is in the D ₁ or more tube outer diameter D _2, the removal of the optical fiber inserted and tubed optical fiber comprising an outer diameter of D ₁ tube it can.

In addition, various other embodiments of the present invention are possible. For example, the core diameter, coating diameter and thickness, material, structure and the like of the optical fiber core are not limited to the above.

[0053]

The present invention exhibits the following excellent effects.

(1) The coating can be optimally held with the minimum necessary force, thereby reducing the coating removing resistance and greatly simplifying the coating removing operation.

(2) The lock mechanism can receive the reaction force of the cover member, and the work of removing the coating can be further facilitated.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a coating removing tool according to the present invention.

FIG. 2 is a perspective view for explaining a coating removing method according to the present invention.

FIG. 3 is a perspective view for explaining a coating removing method according to the present invention.

FIG. 4 is a longitudinal sectional front view showing a state of an eccentric cam before removing coating.

FIG. 5 is a longitudinal sectional front view showing a state of the eccentric cam at the time of removing the coating.

FIG. 6 is a perspective view showing the optical fiber core after the coating is removed.

FIG. 7 is a longitudinal sectional side view showing a cut state of a coating.

FIG. 8 is an enlarged vertical sectional side view of a main part showing another embodiment.

FIG. 9 is a perspective view showing a coating removing tool according to the prior application.

FIG. 10 is a perspective view for explaining a coating removing method according to the prior application.

FIG. 11 is a longitudinal sectional view showing an optical fiber cable.

FIG. 12 is a perspective view showing a conventional coating removing tool.

FIG. 13 is a perspective view for explaining a conventional coating removing method.

[Description of Signs] 1 Cover removal tool 2, 3 Holding member 4, 5 Base member 6, 7 Cover member 13 Slide mechanism 16 Split blade 17 Fixed blade 18 Movable blade 32 Eccentric cam 36 Lock mechanism 51 Optical fiber core wire 57 Coating t thickness

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazuya Murakami 5-1-1, Hidaka-cho, Hitachi-shi, Ibaraki Hitachi Cable, Ltd. Opto-System Research Laboratories (72) Inventor Norifumi Shiina Sunasawa-cho, Hitachi-shi, Ibaraki 880 Hitachi Cable Co., Ltd. Takasago Plant (72) Inventor Takeshi Takeshi 5-1-1 Hidakacho, Hitachi City, Ibaraki Prefecture Hitachi Cable Co., Ltd. Optro System Research Laboratories

Claims (4)

[Claims] 1. A tool for removing coating of an optical fiber core having a coating of a predetermined thickness on an outer peripheral portion, comprising: a pair of holding members for holding the optical fiber core at a close position along a longitudinal direction thereof. And a plurality of split blades provided on one of the holding members and cutting the coating of the held optical fiber core wire from the radial outside, for moving the holding member apart from each other along the core wire longitudinal direction. And a pressing means provided on one of the holding members, the pressing means being moved by a frictional force with the coating when the holding member moves away from the holding member to press the coating against the inner surface of the holding member. A coating stripping tool for an optical fiber. 2. The optical fiber stripping tool according to claim 1, wherein said pressing means comprises an eccentric cam. 3. The holding member comprises a base member on which the optical fiber core is seated and a cover member which covers the base member so as to be openable and closable. The holding member locks the cover member in a closed state. 3. The tool for removing sheath of an optical fiber according to claim 1, further comprising a lock mechanism. 4. A method for removing coating of an optical fiber core having a coating of a predetermined thickness on an outer peripheral portion, wherein the optical fiber core is held by a pair of holding members at close positions along a longitudinal direction thereof. Then, the coating of the held optical fiber core wire is cut from the outside in the radial direction with a plurality of divided blades of one of the holding members, and these holding members are separated from each other via a slide mechanism. A method for removing a coating from an optical fiber core, comprising: moving a pressing means by a frictional force with the coating, and removing the coating while pressing the coating against the inner surface of the holding member by the pressing means.