JPH0980277A - Optical cable and its manufacturing method - Google Patents

Abstract

(57) [Summary] [Structure] An optical fiber cable for small-scale demand. Spiral material 41 spirally wrapped with plastic tape
Is wound around the assembled optical fiber core wire 14,
A loose tube 42 is formed. It is passed through a jerry tank to be filled with a water blocking material (jelly) 16 inside, and a tape is wound on the outside to form a leak prevention layer 44, thereby forming an optical unit 46. It is the same as the conventional case that the sheath 20 is coated thereon to form the optical cable 48. [Effect] Loose tube 42 with spiral material 41
However, since the leak prevention layer 44 is provided, there is no risk of the jelly 16 leaking during manufacturing. Since the diameter of the loose tube 42 is determined by the size of the spiral material 41, 1
It is possible to manufacture cables of various sizes with a single device. The filling amount of the jelly 16 can be easily controlled. The manufactured optical cable itself is easy to branch back, has flexibility, and is easy to bend.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical cable, particularly a small-core cable used for small-scale demand, in which an optical fiber core wire is housed in a loose tube and a waterproof material (jelly or the like) is filled. And the manufacturing method thereof.

[0002]

2. Description of the Related Art FIG. 3 shows a conventional example of a small-fiber cable filled with a waterproof material (jelly or the like). (A) is a cross section,
(B) is a model showing the state viewed from the side. A loose tube 12 is made of a thin plastic pipe as shown in FIG. Reference numeral 14 is an optical fiber core wire, which is composed of a single core or a tape. 16 is a waterproof material,
It consists of Jerry and others. An optical unit 18 is configured by the loose tube 12, the optical fiber core wire 14, and the water blocking material (jelly) 16 described above. Reference numeral 20 denotes a sheath in which two tension members 22 are embedded. Reference numeral 23 represents the entire cable.

The above cable is manufactured as follows. As shown in FIG. 4 (a), a plurality of optical fiber core wires 14 are sent out from the sending machine 13, and they are assembled at the base 24 (narrowing the mutual distance). The loose tube 12 is continuously extruded by the extruder 26 around the assembled optical fiber core wires 14. At that time, the extruder 2
A waterproof material (jelly) 16 is fed into the loose tube 12 through the crosshead 6 to be filled. The optical unit 18 produced as described above is wound on the reel 28.

Next, as shown in FIG. 1B, the optical unit 18 is continuously sent out from the reel 28 and the extruder 30 is used.
Thus, the sheath 20 is extruded and covered. At that time, the tension member 22 is also fed at the same time and embedded in the sheath 20. The optical cable 23 is manufactured as described above and wound on the reel 32.

[0005]

The above-mentioned optical cable 23
As such, it has the following structural problems. The loose tube 12 is hard, hard to bend, and easy to get habit. It is difficult to take out a part of the optical fiber core wire 14 from the loose tube 12 at the time of branching.

Further, the above manufacturing method has the following problems. The size of the loose tube 12 is limited depending on the type of the extruder. In order to change the diameter of loose tube 12, the die of extruder 26 must be changed. Since jelly is injected into the loose tube 12, special dies and nipples are required for the extruder. Since the inside of the loose tube 12 cannot be seen, it is difficult to control the jelly filling rate. That is, the amount of jelly filling can be confirmed only by cutting the cable after manufacturing for a certain length and comparing the volume of jelly (calculated from the weight and the specific gravity) with the inner volume of the loose tube 12.

[0007]

As illustrated in FIG. 1,
A spiral material 41 (FIG. 7C) in which a plastic tape is spirally wound over the entire length is used. A loose tube 42 is obtained by making the spiral material 41 into a state in which the spiral interval a is almost zero, and the optical fiber core wire 14 is housed in this and a water blocking material (jelly) 16 is filled therein. A leak preventing layer 44 is provided on the tube 42 by winding a tape or the like to form an optical unit 46. The above is the means corresponding to claim 1 of the claims.

In the case of manufacturing, as illustrated in FIG. 2, a step of continuously delivering and assembling the optical fiber core wires 14 and an assembling spiral material 41 in which a plastic tape is spirally wound over the entire length are assembled. A step of continuously forming the loose tube 42 by winding the spiral fiber a around the optical fiber core wire 14 in a state where the spiral interval a is almost zero, and a water-stopping material (jelly) in the loose tube 42.
The cable is manufactured by a method including a step of filling 16 and a step of continuously forming the leak prevention layer 44 on the loose tube 42. The above is the means corresponding to claim 2 of the claims.

The above-mentioned spiral material 41 is an important element of the present invention, and only this is taken out and shown in FIG. 1 (c). This is a spirally wound plastic tape made of nylon, polyethylene or the like having a certain elasticity. This thickness changes depending on the number of optical fiber core wires 14 housed inside.

The state where the spiral interval a is almost zero means that the spirals may be in contact with each other or a slight gap may be present. Bobbin 40
By adjusting the revolution speed and the running speed of the optical fiber core wire 14, the spiral interval of the spiral material 41 after being wound around the optical fiber core wire 14 can be made almost zero.

To wind the spiral material 41 around the optical fiber core wire 14, as shown in FIG.
The bobbin 40 for feeding 1 may be revolved around the optical fiber core wire 14.

The leakage prevention layer 44 may be formed by winding a plastic tape or by vertically attaching a wide tape.

[0013]

[Operation] When the loose tube 42 is formed of the spiral material 41, post branching becomes easy. That is, when a part of the spiral material 41 is cut and unwound, the optical fiber core wire 1
4 can be easily taken out, and when it is wound again, it becomes almost the same as the original spiral material 41.
The optical fiber core wire 14 can be easily pulled out from the helix by slightly expanding the helix spacing. When the loose tube 42 is formed of the spiral material 41, the cable can be bent easily. When the loose tube 42 is formed by the spiral material 41 in which the spiral interval is almost zero, and the leak prevention layer 44 is provided thereon, the water blocking material (jelly) 16 filled in the loose tube 42 is exposed to the outside. It doesn't leak.

When the loose tube 42 is formed of the spiral material 41, the loose tubes 42 of various sizes can be manufactured by one apparatus by using the spiral materials 41 having different diameters. There is no need to change dies as in the past. Loose tube 42 formed by spiral material 41
If you fill the inside with water-stopping material (jelly) 16,
Air and excess jelly are discharged from the spiral gap, so it can be filled in a proper state with almost no voids.

[0015]

EXAMPLE A single-core fiber was used as the optical fiber core wire 14, and the 10-fiber optical fiber core wire 14 was assembled by a base 24.
As the spiral material 41, a nylon tape having a width of 6 mm and a thickness of 0.55 mm spirally wound to an outer diameter of 3.0 mm was used. The bobbin 40 wound with the spiral material 41 was revolved around the optical fiber core wire 14, and the spiral material 41 was wound around the assembled optical fiber core wire 14 to form a loose tube 42. At that time, the revolution speed of the bobbin 40 and the traveling speed of the optical fiber core wire 14 were adjusted so that the spiral interval a after being wound around the optical fiber core wire 14 was almost zero.

As the water blocking material (jelly) 16, petrolatum type jelly was used. The optical fiber core wire 14 wound with the spiral material 41 was passed through the jelly tank 50, and the water blocking material (jelly) 16 was filled inside. On tape 43,
Use a non-woven fabric with a width of 10 mm, and wind this in the direction opposite to the spiral of the loose tube 42 to prevent leakage.
4 was formed. By forming the leakage prevention layer 44, it was possible to prevent the leakage of the water blocking material (jelly) 16 even though the loose tube 42 was spiral.

The optical unit 46 is formed as described above, and thereafter, the sheath 20 is extruded and covered thereon to form an optical cable 48 as in the case of the conventional cable.
The outer diameter of the optical cable 48 is 7.0 mm.

[0018]

【The invention's effect】

 (1) The present invention described in item 1 has the following effects. Post branching is easy. Flexible and easy to handle.

(2) The present invention described in item (2) has the following effects. Although the loose tube 42 is formed of the spiral material 41, the leak preventive layer 44 is provided on the loose tube 42, so that the water blocking material (jelly) is provided until the sheath 20 is covered.
16 can be prevented from leaking. Since the diameter of the loose tube 42 is determined by the size of the spiral material 41, cables of various sizes can be manufactured with one device. The appropriate filling amount of the water blocking material (jelly) 16 can be easily controlled. It can also be manufactured with a collective machine. The setup of the device is simplified and the manufacturing time is shortened. It can be manufactured with one unit, which saves time.

[Brief description of drawings]

FIG. 1 is an explanatory view of an embodiment of an optical cable of the present invention,
(A) is a cross section, (b) is a side view, and (c) is the spiral member 41 taken out.

FIG. 2 is an explanatory diagram of an embodiment of a method for manufacturing an optical cable according to the present invention.

FIG. 3 is an explanatory diagram of an example of a conventional optical cable.

FIG. 4 is an explanatory view of an example of a conventional optical cable manufacturing method.

[Explanation of symbols]

 12 Loose Tube 13 Feeder 14 Optical Fiber Core 16 Water Stopper (Jerry) 18 Optical Unit 20 Sheath 22 Tension Member 23 Optical Cable 24 Base 26 Extruder 28 Reel 30 Extruder 32 Reel 40 Bobbin 41 Spiral Material 42 Loose Tube 44 Leak prevention layer 46 Optical unit 48 Optical cable 50 Jerry tank

Claims (2)

[Claims] 1. An optical fiber core wire is housed in a loose tube formed by spirally winding a plastic tape over the entire length so that the spiral interval is close to zero, and the spiral fiber is placed on the loose tube. An optical cable comprising a leak preventive layer and an optical unit in which the loose tube is filled with a water blocking material (jelly). 2. A step of continuously delivering and assembling optical fiber cores, and a spiral material, in which a plastic tape is spirally wound over the entire length, around the assembled optical fiber cores, and a spiral interval is almost zero. A step of continuously forming a loose tube by winding in a state close to, a step of filling a water blocking material in the loose tube, and a step of continuously forming a leakproof layer on the loose tube,
A method for manufacturing an optical cable, comprising: