JP2003066292A - Optical fiber cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical fiber cable reducing costs for production facilities. SOLUTION: In the optical fiber cable 1 constructed by covering a cable core comprising a plurality of cores of tape optical fiber cable 2, of which the outer periphery is covered with a buffer body 3, and tension bodies 4 with an exterior covering 5, the cores of tape optical fiber cable 2 are slued around with an SZ twist.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber cable in which an optical fiber tape core wire is formed into a cable.

[0002]

2. Description of the Related Art An optical fiber cable used for a communication line or the like has a structure in which a large number of optical fibers are assembled to give strength. For example, as shown in FIG. 1, a conventional optical fiber cable 1 twists a plurality of laminated optical fiber tape core wires 2 in one direction and twists the outer circumference of the optical fiber tape core wires 2 in one direction. Formed by covering a cable core covered with a cushioning body 3 (for example, a string-like material such as a plastic yarn) and a tensile strength body 4 arranged outside the cable core with a jacket 5 made of a thermoplastic resin. ing.

[0003]

In order to manufacture the above-mentioned optical fiber cable 1, a plurality of optical fiber ribbons 2 are twisted in one direction, and a buffer 3 is twisted in one direction on the outer periphery thereof. It requires a turning machine. However, these two
There is a problem in that the cost of manufacturing equipment increases because each of the gathering machines of the table rotates the sending and winding drums.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems. According to the invention of claim 1, a cable core in which the outer circumference of a plurality of optical fiber ribbons is covered with a buffer body. In an optical fiber cable in which the and the tensile strength member are covered with an outer jacket, the optical fiber ribbon is twisted into an SZ twist. The invention according to claim 2 is characterized in that, in the invention according to claim 1, the buffer body is twisted into an SZ twist. Here, the SZ twisting is a twisting method in which the twisting direction in the longitudinal direction periodically changes to right twisting and left twisting.

According to the first aspect of the present invention, the plurality of optical fiber ribbons are twisted into the SZ twist, and the optical fiber ribbon assembling machine is a feeding and winding drum that does not require rotation. And an SZ reversing machine that alternately twists the assembly die to the left and right to impart twist. Therefore, this assembly machine is less expensive than a conventional assembly machine that twists in one direction (the delivery and take-up drum rotates), and the manufacturing equipment cost is reduced. Further, according to the invention of claim 2, all of the plurality of optical fiber ribbons and the buffers on the outer periphery thereof are twisted into SZ twists. It is cheaper than a collective machine that twists in the direction, and the manufacturing equipment cost is further reduced.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an embodiment of an optical fiber cable according to the present invention will be described with reference to FIG. In FIG. 1, an optical fiber cable 1
Is a stack of six 4-fiber optical fiber ribbons 2
A cable core, which is twisted with a Z twist, and the outer circumference of the twisted optical fiber tape core wire 2 is twisted and covered in one direction by a buffer body 3, and a tensile strength member 4 disposed outside the cable core. The outer sheath 5 is made of a thermoplastic resin and covers the cable core and the strength member 4. This embodiment is different from the conventional example in that the laminated optical fiber ribbons 2 are twisted by SZ twist.
The cross-sectional shape of this embodiment is no different from the cross-sectional shape of the conventional optical fiber cable.

In this embodiment, an optical fiber ribbon is used by using an assembling machine including a feeding and winding drum that does not require rotation and an SZ reversing machine that alternately twists a collecting die in the middle to the left and right to provide twisting. Since 2 is twisted by SZ twist, the equipment cost of the gathering machine is lower than that of the conventional gathering machine twisted in one direction.

Further, in the above-mentioned embodiment, the buffer 3 is twisted in one direction, but the buffer 3 may be twisted by SZ twisting like the optical fiber ribbon 2. In that case, the equipment costs of the two aggregation machines are both reduced.

When the transmission characteristics, mechanical characteristics, and temperature characteristics of the optical fiber cable 1 of the above-mentioned embodiment were evaluated, it was found that the laminated body of the optical fiber tape core wire 2 and the buffer body 3 were twisted by unidirectional twisting. It was possible to obtain good results comparable to those of the optical fiber cable of.

The present invention is not limited to the above embodiment, and for example, the number of tensile strength members 4 may be other than two, and the number of laminated members of the optical fiber ribbon 2 may be plural.

[0011]

As described above, according to the first aspect of the present invention, the optical fiber ribbon is twisted in the SZ twist, and therefore, compared with the conventional twist in one direction. Therefore, there is an excellent effect that the manufacturing equipment cost is reduced.
According to the second aspect of the present invention, since both the optical fiber ribbon and the buffer body are twisted into the SZ twist, there is an excellent effect that the manufacturing equipment cost is further reduced.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an optical fiber cable.

[Explanation of symbols]

1 optical fiber cable 2 Optical fiber ribbon 3 buffer 4 Strength member 5 jacket

Claims (2)

[Claims] 1. An optical fiber cable comprising a cable core having a plurality of optical fiber ribbons coated with a buffer material on the outer periphery thereof and a tensile strength body coated with a jacket, wherein the optical fiber ribbons are SZ twisted. An optical fiber cable characterized by being twisted. 2. The optical fiber cable according to claim 1, wherein the buffer body is twisted into an SZ twist.