JP3234720B2 - Fiber optic cable - Google Patents

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 mainly used indoors, and aims at improving the handleability of a cable terminal.

[0002]

2. Description of the Related Art Conventionally, as an optical fiber cable used indoors, an optical fiber cable formed by applying a tensile fiber to one optical fiber core and applying a PVC (polyvinyl chloride) jacket thereon. Fiber cords are assembled around a strength member, and a cable jacket is applied on the fiber cord.

FIG. 2 illustrates an example of a conventional indoor optical fiber cable. FIG. 2 (A) is a sectional view of the optical fiber cable, and FIG. 2 (B) is an optical fiber cable used for the optical fiber cable. It is sectional drawing of a fiber cord. In the figure,
1 is a tensile strength wire, 2 is a resin coating, 3 is an optical fiber cord,
Reference numeral 4 denotes an upper winding tape, 5 denotes a cable jacket, 6 denotes an optical fiber core, 7 denotes a tensile fiber, and 8 denotes a cord jacket.

[0004] In this example, the optical fiber cable is shown in FIG.
As shown in (A), a tensile strength member is formed by applying a resin coating 2 around a tensile strength wire 1, and twelve optical fiber cords 3 are twisted and assembled thereon, and an upper winding tape 4 is wound thereon. A cable jacket 5 is provided thereon. As the tensile strength wire 1, a metal wire, an inorganic fiber wire, or the like is used, and as the cable jacket, PVC or the like is used. The number of optical fiber cords 3 to be assembled is about ten, but there are cases where several tens are divided into a plurality of layers and assembled.

[0005] As shown in FIG. 2 (B), the optical fiber cord 3 used in this optical fiber cable is provided with a cord jacket 8 along with a tensile fiber 7 around an optical fiber core 6. Have been. The cord jacket 8 is also made of PVC or the like.

[0006] In such an optical fiber cable used indoors, a code number is usually provided on a jacket of each optical fiber cord in order to improve the discriminability of each optical fiber cord at a cable terminal. Measures such as continuous printing in the longitudinal direction are applied.

However, when such a conventional optical fiber cable is used, several tens of optical fiber cords come and go out of the cable terminal, so that the optical fiber cords are stored in a storage rack for handling. In this case, it is necessary to store the extra length generated by the number of optical fiber codes. Usually, one line (upper and lower lines) is set for two optical fiber cords. Therefore, it is necessary to search for the optical fiber cord of the other party while confirming the code number and make a connection. There were drawbacks such as.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has been made to reduce the number of times of storing the extra length of optical fiber cords in a storage rack, and to use two optical fiber cords. It is an object of the present invention to provide an optical fiber cable that can be easily handled by being able to confirm in pairs.

[0009]

According to the present invention, in an optical fiber cable, a plurality of optical fiber cords each having a tensile fiber layer and a jacket layer provided in this order on the outer periphery of an optical fiber core are assembled around a tensile member, In an optical fiber cable provided with a cable jacket, two adjacent optical fiber cords are joined, and the joining is a weak joining that can be easily separated.

[0010] The joining is performed continuously or intermittently in the longitudinal direction, and the joining is performed by adhesion.

The weak bonding state in which the bonding can be easily separated can be easily separated, for example, in a state where the two bonded optical fiber cords can be separated by grasping with a finger and pulling by hand. In this manner.

[0012]

According to the present invention, since two optical fiber cords are joined to form one set, identification at the terminal is easy, and since the joining can be easily separated, connection to terminal equipment or the like is possible. Work becomes easy.

[0013]

FIG. 1 illustrates an embodiment of an optical fiber cable according to the present invention. FIG. 1 (A) is a sectional view of the optical fiber cable, and FIG. 1 (B) is used for the optical fiber cable. It is sectional drawing of an optical fiber cord. In the figure, FIG.
The same parts as those described above are denoted by the same reference numerals and description thereof will be omitted. 9
Is a joint.

As shown in FIG. 1B, two optical fiber cords are joined at a joint 9 in the optical fiber cord. As shown in FIG. 2B, one optical fiber cord is provided with a cord jacket 8 made of PVC or the like along a tensile fiber 7 around an optical fiber core wire 6. I have. The two optical fiber cords can be joined by bonding with an adhesive, and the cord jacket can be joined with a solvent in the same manner as the adhesive. For example, when PVC is used as a material for the cord jacket, two optical fiber cords can be bonded in the longitudinal direction using an organic solvent such as ethyl methyl ketone.
The bonding can be performed continuously or intermittently in the longitudinal direction.

When extruding and covering the cable jacket without using an adhesive, the cable jacket may be joined so that two cables are simultaneously coated and the cable jacket is integrated.
When the joining width of the joining portion is large, a cut may be made in the width direction and / or the longitudinal direction so as to reduce the joining area.

FIG. 1 is a sectional view of an embodiment of an optical fiber cable formed by using the optical fiber cord.
It is shown in (A). An optical fiber cord 3 is helically wound around a strength member in which a resin coating 2 is applied around a strength line 1. In order to stabilize the shape, it is also effective to simultaneously wind an intervening material such as a polypropylene yarn around the gap between the optical fiber cords 3. An upper winding tape 4 is wound on the twisted optical fiber cord, and a cable jacket 5 is extruded and coated on the outermost layer. In addition,
The number of optical fiber cords 3 is 6 pairs in this embodiment, provided that the two joined fibers are counted as one pair.
It is changed as needed. Further, it can be arranged in two or more layers.

[0017]

As is apparent from the above description, according to the present invention, since two optical fiber cords are combined and assembled as a pair, when the optical fiber cable is terminated on the storage rack, Compared with the conventional optical fiber cable in which the optical fiber cords are gathered one by one, not only the identification of the optical fiber cord is improved, but also the number of times of storing the extra length of the optical fiber cord in the storage rack is halved. However, there is an effect that a significant time reduction can be expected for the entire work required for the cable terminal processing work. In particular, the effect increases as the number of optical fiber cords increases.

[Brief description of the drawings]

FIG. 1 is a view for explaining an embodiment of an optical fiber cable of the present invention. FIG. 1 (A) is a cross-sectional view of the optical fiber cable, and FIG. 1 (B) is an optical fiber cord used for the optical fiber cable. It is sectional drawing.

FIG. 2 illustrates an example of a conventional indoor optical fiber cable. FIG. 2 (A) is a sectional view of the optical fiber cable, and FIG. 2 (B) is an optical fiber cable used for the optical fiber cable. It is sectional drawing.

[Explanation of symbols]

1 ... tensile strength wire, 2 ... resin coating, 3 ... optical fiber cord,
4: Top-wound tape, 5: Cable jacket, 6: Optical fiber core wire, 7: Tensile fiber, 8: Cord jacket, 9: Joint part

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Shusuke Suesuke 1-6-1, Uchisaiwaicho, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Corporation Examiner Eiichi Yoshida (56) References JP-A-2-259611 (JP, A) JP-A-62-262808 (JP, A) JP-A-56-162705 (JP, A) JP-A-2-270216 (JP, A) JP-A-52-18338 (JP, A) −193205 (JP, U) Hira 1-169210 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G02B 6/44

Claims (3)

(57) [Claims] 1. A tensile fiber layer on the outer periphery of an optical fiber core,
A plurality of optical fiber cords provided with a coating layer in order are assembled around a tensile strength member, and in an optical fiber cable provided with a cable coating, the optical fiber cords are connected to adjacent two
An optical fiber cable to which a book is joined and the joint is a weak joint that can be easily separated. 2. The optical fiber cable according to claim 1, wherein the joining is performed continuously or intermittently in a longitudinal direction. 3. The optical fiber cable according to claim 1, wherein the joining is performed by bonding.