JPH0559413U - Optical fiber cable - Google Patents

Abstract

(57) [Summary] [Object] To realize an optical fiber cable which is light even if the cross-sectional areas of the tension member and the coating layer are large, is highly flexible, and is easy to peel off the coating layer. [Structure] A tension member 1 is arranged at the center, a coating layer 2 is provided on the outer periphery thereof, and a plurality of slot units 3 are twisted and gathered on the outside of the coating layer 2. A plurality of tape-shaped optical fiber core wires 6 are stacked and accommodated in a spiral groove 5 provided on the outer periphery so as to open to the outside, and an optical fiber cable is formed by holding a presser winding 7 on the outside thereof. In the bull, holes 8 were formed in the coating layer 2 along its length. [Effect] Since the hole 8 is provided, it is lightweight and highly flexible, and the coating layer is easily separated from the tension member.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an improvement of an optical fiber cable in which a tape-shaped optical fiber core wire is housed in a groove of a slot.

[0002]

[Prior Art]

 In a conventional optical fiber cable, as shown in FIG. 3, a tension member 1 is arranged at the center, a coating layer 2 is provided on the outer periphery thereof, and a plurality of slot units 3 are twisted outside the coating layer 2. The slot unit 3 is assembled, and a plurality of tape-shaped optical fiber core wires 6 as shown in FIG. 4 are laminated in a spiral groove 5 provided to the outside of the slot 4 so as to open to the outside. It is then housed, and a presser wrap 7 is applied to the outside.

In this optical fiber cable, as the number of tape-shaped optical fiber cores 6 is increased to make a multi-core cable, the number of slot units 3 increases, and accordingly, the tension members 1 and The cross-sectional area of the portion (inner portion) 9 of the coating layer 2 becomes large.

[0004]

[Problems to be solved by the device]

 The larger the cross-sectional area of the inner portion 9 of the optical fiber cable, the heavier the weight becomes and the more difficult it is to bend (poor flexibility). Therefore, the handling during installation and transportation is troublesome. Further, when the optical fiber cables are connected to each other, the tension member 1 is fixed in the closure, so that the coating layer 2 on the outer periphery of the tension member 1 needs to be peeled off. The more difficult the peeling is.

An object of the present invention is to realize an optical fiber cable which is light even if the cross-sectional area of the inner portion of the optical fiber cable is large, is not easily bent, and is easy to peel off the coating layer.

[0006]

[Means for Solving the Problems]

 In the optical fiber cable of the present invention, as shown in FIG. 1, a tension member 1 is arranged at the center, a coating layer 2 is provided on the outer periphery thereof, and a plurality of slot units 3 are twisted outside the coating layer 2. As shown in FIGS. 1 and 4, the slot unit 3 is assembled into a plurality of tape-shaped optical fiber core wires 6 in a spiral groove 5 provided on the outer periphery of the slot 4 so as to open to the outside. In an optical fiber cable formed by stacking and accommodating sheets, and applying a press winding 7 on the outside thereof, a hole 8 is formed in the coating layer 2 along the longitudinal direction thereof as shown in FIGS. 2 (a) and 2 (b). It was done.

[0007]

[Action]

 In the optical fiber cable of the present invention, since the hole 8 is formed in the coating layer 2 along the longitudinal direction thereof, the weight of the optical fiber cable can be reduced correspondingly, and the optical fiber cable can be flexible. Thus, the peeling of the coating layer 2 becomes easy.

[0008]

【Example】

 FIG. 1 shows a cross section of one embodiment of the optical fiber cable of the present invention. In FIG. 1, 1 is a tension member, and 2 is a covering layer 2 made of polyethylene, foamed polyethylene, or the like, which is provided on the outer periphery of the tension member 1 so that it is located at the center.

Reference numeral 8 in FIG. 1 denotes a hole, which is formed in the coating layer 2 when the optical fiber cable is manufactured. The shape, length, number, etc. of the holes 8 are not particularly limited. The end surface shape of the hole 8 in FIG. 1 is a perfect circle, and the end surface shape of the hole 8 in FIG. 2A is a substantially trapezoidal shape in which the inner side and the outer side are slightly curved.

The holes 8 may be continuous in the longitudinal direction of the coating layer 2, but as shown in FIG. 2 (b), the holes 8 are made to have a length of several meters or less and intermittently provided in the longitudinal direction of the coating layer 2. May be formed as desired. By doing so, it is possible to prevent water from running in the hole 8. In order to form the holes 8 intermittently in the longitudinal direction of the coating layer 2, for example, a continuous hole is formed in the longitudinal direction by an extrusion coating method, and immediately after extrusion coating, the holes are crushed at appropriate intervals to intermittently fill the solid portion. It is easy to make a hole and form holes 8 on both sides of the solid part.

Although four holes 8 in FIGS. 1 and 2 are formed at equal intervals in the circumferential direction of the coating layer 2, the number may be any other number. Further, it may be a hole 8 spirally extending around the tension member 1.

In the optical fiber cable of the present invention, a plurality of (10 in FIG. 1) slot units 3 are twisted around the outer periphery of the coating layer 2 having holes 8 along the longitudinal direction thereof. Has been assembled. In this slot unit 3, a plurality of optical fiber tape core wires 6 are stacked and housed in a spiral groove 5 that opens to the outside of the slot 4, and a presser wrap 7 is provided on the outer side of the optical fiber tape core wire 6 by a water absorption tape or the like. It has been subjected.

Further, in the optical fiber cable of the present invention, as shown in FIG. 1, a water absorption tape 10 is wound around the outer circumference of the plurality of twisted slot units 3 and a polyethylene seal 11 is provided on the outer side thereof. It has been given.

[0014]

[Effect of the device]

 The optical fiber cable of the present invention has the following effects. ． A multi-fiber cable is lighter and more flexible than an optical fiber cable with a conventional structure, which makes it easier to handle during manufacturing, laying work, and connecting work. ． Since the coating layer 2 is easily separated from the tension member 1, the tension member 1 can be easily taken out. ． Since the material of the coating layer 2 is reduced by the amount of the holes 7, the material cost is reduced.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of an optical fiber cable of the present invention.

FIG. 2 is a vertical cross-sectional view of an inner portion showing another embodiment of the optical fiber cable according to the present invention.

FIG. 3 is a vertical sectional view showing a conventional optical fiber cable.

FIG. 4 is a perspective view showing a laminated state of optical fiber ribbons.

[Explanation of symbols]

 1 Tension Member 2 Covering Layer 3 Slot Unit 4 Slot 5 Spiral Groove 6 Optical Fiber Core 7 Presser Winding 8 Hole

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Creator Kazuo Hokari 1-1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corporation

Claims (1)

[Scope of utility model registration request] 1. A tension member 1 is arranged at the center,
A coating layer 2 is provided on the outer periphery thereof, and a plurality of slot units 3 are twisted and gathered on the outer side of the coating layer 2, and the slot unit 3 is provided on the outer periphery of the slot 4 so as to open to the outside. An optical fiber cable having a plurality of tape-shaped optical fiber core wires 6 stacked and accommodated in a groove 5 having a shape and a press winding 7 provided on the outer side thereof. An optical fiber cable characterized in that a hole 8 is formed along the optical fiber cable.