JPS6118723B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing an optical cable and a tape used therefor.

The inventor filed a patent application on July 25, 1978.
No. 52-89464 describes a method for manufacturing an optical cable in which a tape and optical fibers are fed out from a rotating cage and assembled and twisted in a gathering die. This paper describes the manufacturing process in which the optical fiber is accommodated in the recess of the bent tape just before it is folded.

In this method, increasing the thickness of the tape to increase the mechanical strength of the cable increases the bending force of the tape, making it difficult to manufacture.

The present invention solves this problem by using a tape with a groove carved in the position where the crease should be formed (a continuous straight line in the length direction of the tape), and then forming the tape at the groove. This method takes advantage of the fact that it is easy to bend. The present invention will be explained below with reference to the attached drawings.

Figure 1 shows one of the cable structures described in Japanese Patent Application No. 52-89464, in which six optical fibers 1 are housed in a tape 2 bent into a V-shaped cross section and twisted together. A cross-section of the resulting cable is shown. FIG. 2 shows another cable structure described in the same application, in which four optical fibers 1 are housed in a tape 3 bent into a U-shaped cross section, and a central tension member 4 is connected to the cable structure. This shows a cross section of a cable that has been twisted together and a tape 5 has been wrapped around its outer periphery.

The present invention provides a method for manufacturing these cables that is further developed, and the cable strength is increased by significantly increasing the thickness of the V-shaped cross-sectional tape shown in FIG. 1 and the U-shaped cross-sectional tape shown in FIG. When increasing the size, use tape with grooves at the folds.

That is, the gist of the present invention is an optical cable manufacturing method in which a tape and optical fibers are fed out from a rotating cage, the cross section of the tape is bent into a desired shape, and the optical fibers are housed in the recesses of the bent tape and assembled. A method for manufacturing an optical cable, characterized by using a tape provided with a thin linear portion at the bending position of the tape, and a method for producing an optical cable, which involves feeding out the tape and optical fiber from a rotating cage, bending the cross section of the tape into a desired shape, and folding the tape. A method for manufacturing an optical cable in which optical fibers are housed in recesses of a bent tape and assembled, characterized by feeding out the tape, then providing a linear thin section at the bending position, and then bending along the linear thin section. This is a method for manufacturing an optical cable.

FIG. 3 shows the principle of forming the V-shaped tape according to the present invention, in which a groove 22 continuous in the longitudinal direction is provided in the center of the thick tape 21. By doing this, the grooves become folds, making it easier to form the V-shaped tape, making it easier to obtain a thicker V-shaped tape.
b shows the case of bending with the groove 22 outside,
In the present invention, either of these is possible. In particular, when the cable is bent with the groove 22 outside as shown in b, when it is assembled as shown in Figure 1, a hollow part is created in the center of the cable, so a high tensile strength wire is inserted into this hollow part as a tension member. It is also possible to enter it as

FIG. 4 shows the principle of forming a U-shaped cross-sectional tape according to the present invention. As in FIG. 3, there are methods a and b in which the tape is bent with the groove 32 inside or outside. The tape used for this purpose is a thick tape 31 in which two grooves 32 are continuously carved in the length direction at the positions where the folds should be formed. It goes without saying that the grooves formed on the tape may be formed on both sides of the tape as shown in FIG.

Further, it is also possible that the thickness is not so deep as to be called a groove, that is, the effect of the present invention can be obtained even if the fold position is made thinner than other parts. The tape fold grooves described above may be created online during the assembly process. This method can be implemented by carving a groove with a cutter or pressing a sharp roller between the time the thick tape is fed out and the time it is bent. Suitable materials for the tape of the present invention include plastics (polyethylene, polyester, polyvinyl chloride) and metals. According to the present invention, since the tape is flat when being fed out, it is possible to
Compared to the case of using a tape formed in a mold, there are fewer problems during unwinding (problems with the winding diameter, bobbin, etc.) and it is easier to implement.

In addition, according to the present invention, since the V-shaped or U-shaped tape can be made thick, the strength of the cable is high and bending can be easily performed, and the jig etc. for bending can be easily used. can be made, speeding up cable manufacturing,
Furthermore, since the bending position can be predetermined before forming, there are many advantages in terms of manufacturing and quality, such as improved bending accuracy.

[Brief explanation of the drawing]

Figures 1 and 2 are cross-sectional views of optical cables showing examples of optical cables to which the present invention is applied, Figures 3 and 4 are diagrams explaining the principles of the present invention, and Figure 5 is a cross-sectional view of an optical cable to which the present invention is applied. It is a sectional view of the tape showing an example. In these figures, 1 is an optical fiber, 2 is a V-shaped tape, 3 is a U-shaped tape, 4 is a tension member, and 5 is a tension member.
2 is a horizontally wound tape, 21 and 31 are tapes of the present invention, and 2
2 and 23 indicate grooves.

Claims (1)

[Scope of Claims] 1. A method for manufacturing an optical cable in which a tape and optical fibers are fed out from a rotating cage, the cross section of the tape is bent into a desired shape, and the optical fibers are housed in the recesses of the bent tape and assembled. A method for manufacturing an optical cable, comprising using a tape having a thin linear portion at a bending position of the tape. 2. An optical cable manufacturing method in which a tape and optical fibers are fed out from a rotating cage, the cross section of the tape is bent into a desired shape, and the optical fibers are accommodated in the recesses of the bent tape and assembled. 1. A method of manufacturing an optical cable, comprising: providing a thin linear portion at a bending position, and then bending the thin linear portion along the thin linear portion.