JPS6334445B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for manufacturing an optical fiber cable.

An optical fiber cable has a structure in which a protective coating (sheath) is applied to an aggregate of a large number of optical fiber core wires for optical transmission. Optical fiber cores have low strength, and their transmission characteristics are easily affected by tension and other external influences, so as a countermeasure, it is necessary to attach a large number of optical fiber cores to a tape-like object in advance, or to attach the core wires to a surface or surface. A tape for optical transmission glass fibers (hereinafter referred to as "optical fiber tape") is made by forming a tape-like plastic into a composite material inside, and this tape is further assembled to form an aggregate. However, since this optical fiber tape has a tape shape, it is not possible to twist a plurality of fibers together and assemble them, as with conventional cables. Therefore, in optical fiber cables using optical fiber tapes, a stacked bundle of multiple optical fiber tapes is used as an assembly. The cross section of the optical fiber cable in this case has a structure in which a sheath 4 is applied to an assembly 1 in which optical fiber tapes 3 comprising optical fiber core wires 2 are bundled in a laminated manner, as shown in FIG. However, when a cable with this structure is sheathed using the conventional method, if the cable is bent during processing or subsequent work, the length difference (expansion/contraction) due to the difference in the radius of curvature between the optical fiber tapes will occur depending on the thickness of the aggregate. ), which causes the optical fiber tape bundle to become disarrayed and the transmission characteristics to deteriorate.

The present invention aims to provide a method and device for manufacturing an optical fiber cable that eliminates the above-mentioned drawbacks by twisting and sheathing a laminated optical fiber tape assembly using a special method and device. This is the purpose.

The present invention will be explained below based on the drawings.

FIG. 2 is a front view showing an embodiment of the present invention in which plastic sheathing is performed using a plastic extrusion device. After forming this plastic sheath, sheathing can be carried out by an aluminum extrusion method, a metal plate made of aluminum, copper, etc., a wrapping method using a plastic band, or the like. An optical fiber tape assembly 1 in which optical fiber tapes are overlapped is wound around a supply bobbin 5. At this time, the aggregate 1 may be slightly twisted. Supply device 7
A cradle 6 is provided on which the supply bobbin 5 is rotatably mounted, and the cradle 6 is rotated by a motor 8 around the direction in which the assembly 1 is fed out, and the number of rotations and the forward and reverse directions can be freely controlled. It's summery. A linear guide 11 is provided which passes through the crosshead 10 of the plastic extrusion coating device 9. As shown in detail in FIG. 3, the linear guide 11 is pipe-shaped and has a rectangular hole in the center through which the optical fiber tape assembly is passed. Therefore, it can be freely controlled and rotated. A die 10 and a point 15 are provided in the crosshead 10 of the plastic extrusion device 9, and the plastic 16 is extruded from the gap formed by the die 10 and the point 15 to form a pipe 17 and sheath the optical fiber tape assembly. The linear guide 11 passes through the inside of the point 15 and projects further forward from the tip of the point 15. The plastic 16 extruded from the die 10 and the point 15 is in a molten state, and is cooled and solidified while passing through a cooling tank 22, which will be described later. Since the optical fiber tape assembly 1 sags due to its own weight and vibrates due to twisting motion, there is a risk of it coming into contact with the molten sheath and adhering. If adhesion occurs, the outer shape of the cable may be deformed, and the cable may be subjected to external forces such as bending. When external force is applied, the external force directly reaches the optical fiber, causing deterioration of the transmission characteristics of the optical fiber. In the structure of the present invention, the protruding linear guide supports the optical fiber tape assembly up to the front of the sheath point and prevents contact between the two until the plastic of the sheath becomes solid, thereby completely preventing the above-mentioned danger. ing. There is a cooling tank 2 in front of the plastic extrusion equipment.
2. A pinch roller 19 for pulling out the cable and a winding device 21 are provided. A capstan or a caterpillar capstan may be used in place of the pinch roller 19, or it may be directly pulled out by a winding device. Optical fiber tape assembly 1
is the supply bobbin 6 that rotates around the feeding direction
The cable 1 is unwound from the cable 1, passes through the hole of the rotating linear guide 11, and is sheathed into the plastic of the sheath formed by the plastic extrusion device.
8 and is cooled in a cooling tank, pulled out by a pinch roller 19, and wound onto a winding bobbin 20 of a winding device. At this time, if there is no twist in the aggregate wound around the supply bobbin, the cradle 6 and the linear guide rotate at the same rotation speed, and if the aggregate is twisted in advance, the rotation of the linear guide is the rotation of the cradle. The number of rotations is adjusted by adding or subtracting the unwinding speed of the aggregate and the rotation corresponding to the torsion. The torsion applied to the assembly 1, that is, the rotation of the supply bobbin and the linear guide, may be applied in only one direction over the entire length of the cable, or it may be so-called S that the twist direction is reversed every certain length of the cable.
-Z twisting may also be used. The optical fiber cable made in this way has a structure in which it is sheathed around a twisted optical fiber tape assembly, so it cannot be used during the cable manufacturing process when it is wound around a capstan, a take-up bobbin, or during subsequent work. Even if the cable is bent, the expansion and contraction of the optical fiber tape caused by the thickness of the assembly is made uniform, so that the tape does not become disarrayed or the transmission characteristics deteriorate.

Furthermore, to explain another embodiment of the present invention, a normal supply device that does not rotate the supply bobbin around the feeding direction is used, and a linear guide having the above-mentioned structure and a plastic extrusion device are used. If the optical fiber tape assembly is sheathed by rotating it forward and backward for a certain period of time or for a certain length of the assembly, an optical fiber cable in which the assembly is given S-Z twist can be obtained. Similar good fiber optic cables can be obtained. In this case, while the assembly exiting the tip of the linear guide is given an S twist, the assembly on the side entering the linear guide is untwisted and further given an N twist. Therefore, in the case of this embodiment, it is desirable to make the distance between the supply device, the linear guide, and the sheath device sufficiently large.

As described in detail above, the present invention provides an optical fiber tape assembly in which optical fiber tapes are stacked one on top of the other, through a rectangular hole in a rotating linear guide that protrudes forward beyond the head of a sheath coating device in one direction or in an S-Z direction. This is a method and device for manufacturing an optical fiber tape cable that is sheathed by giving a twist in the direction, and since the optical fiber tape cable manufactured by this method has a twisted aggregate, the alignment of the optical fiber tape is maintained even when the cable is bent. No collapse or deterioration of transmission characteristics occurs.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a laminated optical fiber tape cable, Fig. 2 is an overall front view showing an embodiment of the optical fiber cable manufacturing apparatus of the present invention, and Fig. 3 is the structure of the head and linear guide of the sheath device. FIG. 1: Optical fiber tape aggregate, 2: Optical fiber, 3: Optical fiber tape, 4: Sheath,
5: Supply bobbin, 6: Cradle, 7: Supply device, 8, 13: Motor, 9: Sheath extrusion device, 10: Crosshead, die, 11: Linear guide, 12: Wheel, 14: Bearing, 15: Point, 16: Plastics, 17: Sheath pipe, 18: Cable, 19: Pinch roll, 2
0: Winding bobbin, 21: Winding device, 22: Cooling tank, 23: Cooling water.

Claims (1)

[Claims] 1. A large number of optical fiber cores for optical transmission are bonded to a tape-shaped object, or a plurality of plastic tapes with multiple optical fiber cores composited on the surface or inside are stacked and bundled. In a method of manufacturing an optical fiber cable by winding a shaped aggregate around a supply bobbin and sheathing the aggregate fed out from the supply bobbin with a plastic sheath,
A linear guide that restricts the cross-sectional shape of the aggregate and allows the assembly to pass through is passed through the sheath device, protrudes forward from the sheath point, and rotates through a linear guide that twists the aggregate and draws it out, thereby imparting twist to the inside of the sheath. 1. A method for manufacturing a laminated optical fiber cable, characterized by arranging a multi-layered optical fiber cable. 2. The method for manufacturing a laminated optical fiber cable according to claim 1, characterized in that the supply bobbin is fed out while rotating around the feeding direction of the assembly. 3 Torsion in the opposite direction (S-
3. A method for manufacturing a laminated optical fiber cable according to claim 1 or 2, characterized in that the cable is given a Z-twist. 4. A large number of optical fiber cores for optical transmission are bonded to a tape-shaped object, or a bundle-like aggregate is formed by overlapping multiple plastic tapes with multiple optical fiber cores on the surface or inside. A supply device that feeds out a supply device, and a linear guide that has a hole that restricts the cross-sectional shape of the fed out aggregate and allows it to pass through, and that penetrates the inside of the sheath device and projects forward from the sheath point, is provided so as to be able to controllably rotate. 1. An apparatus for producing a laminated optical fiber cable, comprising a sheath coating device, and for pulling out and winding an optical fiber tape cable sheathed by the sheath coating device. 5. Manufacture of a laminated optical fiber cable according to claim 4, characterized by having a supply device having a cradle that rotates around the direction in which the aggregate is fed out and a supply bobbin attached to the cradle. Device.