JP5735402B2 - Optical cable - Google Patents

Description

  The present invention relates to an optical cable provided with one or a plurality of units containing a plurality of optical fibers.

  Conventionally, as an optical fiber cable for communication (optical cable), a cable in which a plurality of units each accommodating a plurality of optical fibers are collected, or a cable that accommodates only one unit may be used. This unit is called an optical fiber ribbon or an optical fiber unit.

  When manufacturing such an optical cable, since the sheath is applied after the unit is covered with a fibrous interposition such as a yarn or a tape-like member, a coarsely wound string is wound so that the intervening is not dispersed when the sheath is applied.

  For example, Patent Document 1 discloses an optical fiber core made of one or more strands or a tape core, and a heat-resistant plastic yarn or an organic fiber or an inorganic fiber vertically attached to surround the optical fiber core. An intervening body made of fiber, a string in which all of the optical fiber cores and the intervening body are roughly wound together, a tensile element for an optical element arranged on both sides in parallel in the vicinity thereof, and a cable covering them An optical cable having a sheath is disclosed.

Further, in Patent Document 2, two or more optical fiber core wires are twisted together with a buffer material disposed around the optical fiber core, a presser winding thread or tape is wound around the outer side of the buffer material, and the presser winding thread or tape is wound. An optical cable is disclosed in which a tensile strength member is disposed outside a rotated optical fiber core and a buffer to further form a sheath (sheath).
By the way, in the operation | work which disassembles an optical cable and takes out a core wire, it is necessary to cut | disconnect a rough wound string with a cutting tool, such as a nipper, after sheath removal.

JP 2004-61964 A JP-A-2005-70127

However, in the conventional optical cables such as the optical cables described in Patent Documents 1 and 2, when cutting the coarse winding string, it is difficult to distinguish between the coarse winding string and the intervening color in a similar color, so that the operator has a really rough winding string. I don't know if it was cut.
Further, the operator may not know the number of coarsely wound strings during the dismantling operation, and in that case, it is not possible to know how many coarsely wound strings should be cut. In particular, when removing the coarsely wound string in a dark place, it is very difficult to distinguish between the coarsely wound string and the intervention.

  The present invention has been made in view of the above-described actual situation, and an object thereof is to provide an optical cable capable of easily distinguishing and cutting a rough winding string at the time of disassembling work.

The optical cable of the present invention is provided with one or a plurality of units containing a plurality of optical fibers, a fibrous interposition is arranged around the one or the plurality of units, and a coarse winding string is wound around the interposition. , The cable is covered with a sheath, and the color of the coarsely wound string is different from the intervening color, and two or more coarsely wound strings are wound in one direction at a fixed pitch with their respective positions shifted . The color of the coarsely wound string is different.

Also, the color of the roughly coiled cord is preferably a fluorescent color.
Further, as the interposition, it is preferable that the yarn is arranged in a unidirectional twist, or that the tape-like member is arranged vertically.

  According to the optical cable of the present invention, since the color of the coarsely wound string is different from the intervening color, it is possible to easily identify and cut the coarsely wound string during the dismantling operation.

It is sectional drawing which shows one structural example of the optical cable which concerns on this invention. It is a perspective view which shows the state which peeled the sheath of the optical cable of FIG. It is sectional drawing which shows the other structural example of the optical cable which concerns on this invention. It is a figure which shows the test result which compared the time required for disassembling the optical cable of this invention with the conventional optical cable.

FIG. 1 is a cross-sectional view showing a configuration example of an optical cable according to the present invention, and FIG. 2 is a perspective view showing a state where a sheath of the optical cable in FIG. 1 is peeled off.
An optical cable 1 illustrated in FIG. 1 includes six optical fiber ribbons 11, and yarns 12 are arranged around the six optical fiber ribbons 11. The optical fiber ribbon 11 is an example of a unit that accommodates a plurality of optical fibers. Moreover, although the number of the optical fiber ribbons 11 is exemplified as six, it is sufficient that one or a plurality of optical fibers are provided.

  Further, although the description will be made on the assumption that the optical fiber ribbon 11 and the yarn 12 are twisted in the same direction, the optical fiber ribbon 11 may be twisted in the opposite direction to the yarn 12, or may be twisted. You may provide in straight shape, without turning. Moreover, although the yarn 12 is unidirectionally twisted, the optical fiber ribbon 11 may be twisted in the SZ direction. The yarn 12 may be made of plastic such as polypropylene (PP) yarn or polyethylene terephthalate (PET) yarn, but may not be made of plastic.

In the optical cable 1 according to the present invention, as shown in FIG. 2, the coarsely wound strings 16a, 16b, and 16c are wound in one direction at a constant pitch from the top of the yarn 12, as shown in FIG. The sheath 15 is covered with two tear strings 13 vertically attached thereto. As described above, the optical cable 1 is covered with the sheath 15 in a state where the coarsely wound strings 16 a, 16 b, and 16 c are wound around the yarn 12.

In addition, two tension members 14, which are steel wires, are also vertically attached inside the sheath 15, and a protrusion 15 a indicating the position of the two tear strings 13 is provided on a part of the sheath 15. .
The tear string 13 and the protrusion 15a do not need to be provided, but are preferably provided because they are convenient during dismantling work. The tension member 14 is provided to maintain the strength of the optical cable 1 and to prevent the optical fiber ribbon 11 from being broken.

  As an example of the optical cable 1 configured as described above, an optical fiber ribbon assembly in which about 5 to 6 optical fiber ribbons 11 are laminated in a twisted or straight manner. Yarns 12 functioning as interpositions around this are gathered around the periphery (coarse winding is wound around as described later), and an optical cable core having a circular cross section with a diameter of about 12 mm is provided. The optical cable 1 is formed by arranging a tear string 13, a tension member 14, and a sheath 15 on such an optical cable core.

  As a main feature of the present invention, the color of the coarsely wound strings 16a, 16b, and 16c wound between the yarn 12 and the sheath 15 is made different from the color of the yarn 12. Examples of the material of the coarsely wound string 16a, 16b, 16c include nylon, polyester, polyethylene, and aramid fiber. For example, since the yarn 12 is often white in the case of such a material, the coarsely wound strings 16a, 16b, and 16c may be colors other than white. In many cases, the yarn 12 is white, but any number of colors may be used.

  By using the coarsely wound cords 16a, 16b, and 16c having a color different from that of the yarn 12 as described above, both of them can be distinguished, and the coarsely wound cords 16a, 16b, and 16c can be easily distinguished during the disassembling work. It is possible to cut the yarn 12 while leaving it.

Moreover, although the example which wound the three coarsely wound strings 16a, 16b, and 16c around the optical cable 1 is given in FIG. 2, the number is not limited to this. However, roughly coiled cord is wound two or more, that the color of each coarse winding strap Do different. If it demonstrates in the example of FIG. 2, the color of the rough winding string 16a, 16b, 16c will be changed, respectively. For example, a color scheme may be adopted in which the yarn 12 is white, the coarsely wound string 16a is black, the coarsely wound string 16b is red, and the coarsely wound string 16c is yellow. In this way, it is preferable to change the color of each coarsely wound string because it is possible to know how many coarsely wound strings should be cut.

  It is also assumed that the optical cable 1 is laid in an underground pipeline. In such a case, the optical cable 1 is often disassembled in a dark place such as a manhole. Therefore, the rough winding removability can be further improved by setting the rough winding strings 16a, 16b, and 16c to a fluorescent color different from that of the yarn 12.

  The above description is based on the premise that the yarn 12 is arranged in the optical cable 1, but the color of the coarse winding cords 16 a, 16 b, and 16 c is different even if other fibrous interpositions are arranged instead of the yarn 12. It only has to be different from the color. For example, a tape-like member may be arranged vertically as a fibrous interposition. Examples of the tape-shaped member include fibrous materials such as a nonwoven fabric and a water-absorbing tape.

  The water-absorbing tape may be a tape-shaped member having a water-absorbing function, and an adhesive layer is provided on at least one surface, and a structure that can be attached to the optical fiber tape core wire 11 and vertically attached is provided. It is preferable to keep it. Further, as the water-absorbing tape, for example, a fibrous tape in which an adhesive is applied to both surfaces and a swelling powder is coated on the surface can be used. This swelling powder has a property (swellability) that absorbs moisture and swells in a short time, and as a result of swelling, it changes into a non-immersible gel-like substance. Therefore, when water reaches the water-absorbing tape, the swollen powder falls off the tape, and the gap between the optical fiber ribbon 11 and the sheath 15 can be filled with a non-immersible substance.

FIG. 3 is a sectional view showing another configuration example of the optical cable according to the present invention.
The optical cable 3 illustrated in FIG. 3 includes six four-core optical fiber units 31 as another example of a unit that accommodates a plurality of optical fibers. In the optical cable 3, yarns 32 are arranged around six optical fiber units 31.

  The optical cable 3 has the same configuration as that of the optical cable 1 in FIG. 1 except for the configuration of the optical fiber unit 31. That is, the optical cable 3 is wound with a coarsely wound string (not shown) similar to that described with reference to FIG. 2 from above the yarn 32, and with two tear strings 33 vertically attached to the periphery thereof. A sheath 35 having a protruding portion 35 a is covered, and two tension members 34 are vertically attached inside the sheath 35.

  As an example of the optical cable 3 configured in this way, as shown in FIG. 3, six optical fiber units 31 having four fibers (or 8 to 40 optical fiber units having a single optical fiber, four optical fibers). 10 fiber units, 5 optical fiber units x 5 and 3 optical fiber units x 8, etc.) The yarns 32 functioning as intervening gathers, and a coiled wire is wound around the yarn 32, and an optical cable core having a circular shape with a cross-sectional diameter of about 3 to 12 mm is provided. The optical cable 3 includes a tear string 33, a tension member 34, and a sheath 35 arranged on such an optical cable core.

The optical cable 3 also has two or more coarsely wound strings wound in one direction at a fixed pitch with the respective positions being shifted, and the color of the coarsely wound string is the same as that of the yarn 32. Different and the color of each of the coarsely wound cords is different. Other application examples are as described for the optical cable 1.
In addition, the optical cable according to the present invention is not limited to the configuration described with reference to FIGS. 1 and 3, and a fibrous interposition and a rough winding string are arranged around a unit that accommodates a plurality of optical fibers, and a sheath is provided. Any coated configuration can be applied.

FIG. 4 is a diagram showing test results comparing the time required to disassemble the optical cable of the present invention with a conventional optical cable. In the test results shown in FIG. 4, in addition to Test Example 1 using the optical cable according to the present invention, Comparative Example 1 using a conventional optical cable as a comparative example and Comparative Example 2 applying some of the features of the present invention are shown. Show. In any of the examples, three coarsely wound cords were used, and a nipper was used for cutting the coarsely wound cords, and the core wire take-out operation time was examined as an average value of three people.

In Comparative Example 1 , the work time was 62 seconds as a result of examining the color of the yarn and the color of the three coarsely wound strings as white. On the other hand, in Comparative Example 2 in which some of the features of the present invention were applied, it took 47 seconds as a result of examining the working time with the yarn color white and the three coarsely wound cords all black. Work time has been shortened. Further, in Test Example 1 according to the present invention, the white color of the yarn, varied three of roughly coiled cord colors respectively, black, red, results of examining the working time as a yellow-consuming 39 seconds, The working time was further shortened compared to Comparative Example 2 .

DESCRIPTION OF SYMBOLS 1,3 ... Optical cable, 11 ... Optical fiber ribbon, 12, 32 ... Yarn, 13, 33 ... Tear string, 14, 34 ... Tension member, 15, 35 ... Sheath, 15a, 35a ... Projection part, 16a, 16b , 16c ... Coarse winding string, 31 ... Optical fiber unit.

Claims (3)

One or a plurality of units containing a plurality of optical fibers are provided, a fibrous interposition is arranged around the one or the plurality of units, and a sheath is covered in a state in which a coarse winding string is wound around the interposition. In the optical cable, the color of the rough winding cord is different from the intervening color, and two or more of the rough winding cords are wound in one direction at a fixed pitch with their positions shifted, An optical cable characterized in that the color of the winding string is different.   The optical cable according to claim 1, wherein the color of the coarsely wound string is a fluorescent color.   The optical cable according to claim 1 or 2, wherein as the interposition, a yarn is arranged in a unidirectional twist, or a tape-like member is arranged vertically.

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