JPH10104477A - Optical cable for outdoor aerial assembly - Google Patents

Abstract

(57) [Summary] An object of the present invention is to provide an optical fiber cable for outdoor aerial assembly in which optical fiber outdoor optical cables can be assembled at high density and can be manufactured efficiently. SOLUTION: This is an imaginary outdoor optical cable in which a large number of grooves 3 are formed by attaching a connecting groove 2 to a core member 1, and an imaginary outdoor optical cable 20 is accommodated in these grooves 3. , A band-shaped bottom plate 8,
A plurality of wall plates 9 erected on the bottom plate 8 along the longitudinal direction thereof, and a band-shaped top plate 9a formed on the top of the wall plate 9
A concave portion 9b is formed on the surface of the top plate 9a, and small grooves 8a, 8b are formed in a portion corresponding to the wall plate 9 on the bottom surface of the bottom plate 8 in the longitudinal direction. .

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an outdoor optical fiber cable in which optical overhead outdoor optical cables used for drawing in a general subscriber's house are assembled.

[0002]

2. Description of the Related Art At present, it is specifically studied to spread an optical fiber communication network to a subscriber's house such as a general home. In this case, as a method of wiring a communication optical fiber from a telephone station or the like to each subscriber's home, for example, a plurality of single-core overhead outdoor optical cables (hereinafter abbreviated as overhead optical cables) for drawing in the subscriber's home are assembled. A method has been proposed in which an optical cable for outdoor aerial assembly (hereinafter abbreviated as an aggregate optical cable) is installed on a utility pole, an aerial optical cable is pulled out from the aggregate optical cable as needed, and the optical fiber cable is pulled into a subscriber's house.

As such a collective optical cable, for example, a cable having a structure as shown in FIG. 9 has been proposed. The collective optical cable of this example has one overhead optical cable 40 and one
The back split pipe 6 is accommodated in the back split pipe 61.
1 is twisted around the tension member 64 by a required number, and a presser winding layer 65 and a sheath 66 are wound around these members.
Are sequentially formed. Tension member 64
Is a steel wire 62 in which a PE (polyethylene) coating 63 is provided on the circumference. The holding roll layer 65 is formed by winding a nonwoven fabric tape or the like, and the sheath 66 is formed by extruding PE.

On the other hand, the aerial optical cable 40 housed in the cracked pipe 61 has a structure in which a cable main body 48 is spirally wound around a support wire 43. The support wire 43 is formed by coating a steel wire having an outer diameter of 1.2 mm with a PVC (polyvinyl chloride) sheath on the outer circumference. In addition, the cable body 48 is configured by disposing two steel wires having an outer diameter of 0.7 mm on both sides of a nylon-coated optical fiber core wire having an outer diameter of 0.9 mm, and integrating them with a PVC sheath. The collective optical cable thus configured is used by being installed on a utility pole or the like. Then, if necessary, a hole of an appropriate size is formed in the sheath 66, the presser winding layer 65, and the back crack pipe 61, and the overhead optical cable 4
0 can be pulled out and wired to the subscriber's house or the like.

[0005] However, in the collective optical cable having such a structure, there is a problem that the accommodation density of the overhead optical cables 40 is low, and if the number of the overhead optical cables 40 to be assembled is increased, the outer diameter of the collective optical cables becomes considerably large. Further, when manufacturing this collective optical cable, a step of inserting one overhead optical cable 40 into one back cracked pipe 61 and a step of twisting a plurality of back cracked pipes 61 around the tension member 64. And a step of forming the presser winding layer 65 and a step of forming the sheath 66, the number of steps is large and the manufacturing efficiency is low.

[0006]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a collective optical cable capable of assembling overhead optical cables at high density and efficiently manufacturing them.

[0007]

According to the present invention, there is provided a collective optical cable in which a plurality of grooves are formed by attaching a connecting groove to a core member, and an aerial optical cable is accommodated in these grooves. Consists of a band-shaped bottom plate, a plurality of wall plates erected on the bottom plate along the longitudinal direction thereof, and a band-shaped top plate formed on the top of the wall plate, and a concave portion is formed on the surface of the top plate. A collective optical cable is characterized in that a small groove is formed in a portion corresponding to a wall plate on the bottom surface of the bottom plate in a longitudinal direction of the bottom plate.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
FIG. 1 is a sectional view showing an embodiment of the collective optical cable of the present invention. In the collective optical cable of this embodiment, a large number (12 in the drawing) of grooves 3 are formed by attaching the connecting groove 2 to the core member 1, and each of these grooves 3 accommodates one overhead optical cable 20, and further connects the optical fiber 20. A presser winding layer 4 and a collective optical cable sheath 5 around the groove 2
Are sequentially formed.

The central member 1 bears the tensile strength of the optical fiber cable, and is made of an appropriate tensile material. In this embodiment, a PE (polyethylene) coating 7 is provided around the steel stranded wire 6. Things are used.

FIG. 2 is a perspective view showing the connecting groove 2 before being attached to the core member 1. This connecting groove 2
A strip-shaped bottom plate 8, a plurality of (13 in the drawing) wall plates 9 erected along the bottom plate 8 along the longitudinal direction thereof, and the wall plate 9
And a band-shaped top plate 9a formed at the top of the horn. The material forming the connection groove 2 is preferably made of an elastically deformable material wound around the core member 1, and can be cut open by a blade when the overhead optical cable is branched from the collective optical cable. Is preferable, for example, PE
A thermoplastic resin such as (polyethylene) is preferably used.

The portions surrounded by the adjacent wall plates 9 and 9 and the bottom plate 8 are concave grooves 9 respectively.
In the connecting groove 2 of this embodiment, twelve grooves 9 are provided along the longitudinal direction of the bottom plate 8. The size of the groove 9 is the required number of the optical fiber cables 2
0, and preferably has a size such that when the connecting groove 2 is wound around the core member 1 as described later, the overhead optical cable 20 is not subjected to side pressure by the wall plates 9 on both sides. .

As shown in FIG. 4, the width of the top plate 9a is such that the connecting groove 2 is formed by the concave portion 9b of the top plate 9a.
The top plate 9a, which is next to the top plate 9a
It is preferable that the end portions 9c, 9c of the 9a are in contact with each other, that is, the total value of the width of the top plate 9a is preferably larger than the outer diameter value of the core member 1, so that the wall plate 9 The effect of preventing movement is more excellent.

As shown in FIG. 3, a concave portion 9b is formed on the surface of the top plate 9a. When such a concave portion 9b is formed in the top plate 9a, the connecting groove 2 is wound around the core member 1. This is because the recess 9b of the top plate 9a comes into close contact with the outer periphery of the core member 1 as shown in FIG. The radius of curvature of the concave portion 9b is preferably substantially the same as the radius of curvature of the outer periphery of the center member 1. In this case, the adhesion between the concave portion 9b of the top plate 9a and the outer periphery of the core member 1 is more improved. It is because it becomes excellent.

Small grooves 8a, 8a are formed in a portion corresponding to the wall plate 9 on the bottom surface of the bottom plate 8 along the longitudinal direction. These small grooves 8a and 8b are provided so as to be located outside the ends of the grooves 3 and 3 on both sides of the wall plate 9 as a center. If such small grooves 8a, 8a are provided, the portion where these small grooves 8a, 8a are formed is easy to bend when the connecting groove 2 is wound around the core member 1, so that the connecting groove 2 is formed on the core member 1. Is easy to wind. When the overhead optical cable 20 is branched from the collective optical cable, when the bottom plate 8 of the connecting groove 2 is cut open using a blade and the overhead optical cable 20 accommodated in the groove 3 is taken out, for example, small grooves at both ends outside one groove 3 are used. 8a and small groove 8
When the bottom plate 8 is cut using a cutting tool along the line b, the bottom plate 8 can be easily cut without damaging the overhead optical cable 20.
Can be cut open. The thickness of the bottom plate 8 and the wall plate 9 is preferably thin in terms of increasing the accommodation density of the aerial optical cable, reducing the diameter of the collective optical cable, reducing the weight, and economical efficiency, but if too thin, the reliability of the collective optical cable deteriorates. .

In the collective optical cable according to the present embodiment, the overhead optical cables 20 are inserted into the grooves 3 of the connecting groove 2 having the above-described configuration, and as shown in FIG.
The concave portion 9b is wound so as to be in close contact with the outer periphery of the core member 1 to form a linear body, and the groove 3 has a fan-shaped profile in cross section as shown in FIG. The optical cable 20 is housed.

The press-winding layer 4 is formed by press-winding so that the connecting groove 2 wound around the outer periphery of the core member 1 does not open, and a non-woven fabric tape or the like is used. The collective optical cable sheath 5 includes a holding roll layer 4.
The outer peripheral surface of the optical fiber cable 20 is provided to protect the connecting groove 2 accommodating the aerial optical cable 20 and the core member 1 from mechanical external force at the time of laying and an environment after the laying, and extrusion coating of an appropriate resin material. It is formed suitably by doing. In the present embodiment, it is formed by extrusion coating PE. The thickness of the collective optical cable sheath 5 is reduced in diameter of the collective optical cable,
Thinner is preferable in terms of weight reduction and economy, but if too thin, the reliability of the collective optical cable deteriorates.

FIG. 6 is a sectional view of the overhead optical cable 20 used in this embodiment. This overhead optical cable 20
The first tension member 21, the second tension member 22a, the optical fiber 23 and the third tension member 22b are sequentially arranged on the same plane, and these are integrated by a sheath 24. . Here, arranging on the same plane means arranging the members in parallel so that the central axis of each member is located on the same plane. Also,
The size of the overhead optical cable 20 in a direction parallel to the plane in which the central axis of each member is located is referred to as a cable height, and the size of the overhead optical cable 20 in a direction perpendicular thereto is referred to as a cable width.

The aerial optical cable 20 has a cross-sectional shape in which a support line portion 20A having a substantially circular cross section is continuous via a neck portion 25 in the longitudinal direction of the cable portion 20B having a substantially elliptical cross section. . The neck 25 is provided with a weakening groove 25a in which a sheath 24 is cut in the cable width direction.
Can be easily cut in the cable width direction, that is, the direction along the line BB 'in FIG. Then, by cutting the aerial optical cable 20 at this position, the first
Support member 20A including the tension member 21 and the sheath 24, and the second and third tension members 22.
a, 22b, a cable portion 20B composed of an optical fiber core 23 and a sheath 24 are cut off. The sheath 24 on the circumference of the optical fiber core 23 is also provided with a weakening groove 26 having a cut in the cable width direction, so that the sheath 24 can be easily torn at the position of the weakening groove 26. ing. By tearing the sheath 24 at this position, the optical fiber core wire 23 can be easily exposed.

The optical fiber 23 is not particularly limited, and single-core optical fibers having various structures can be suitably used. In this embodiment, an optical fiber bare wire is coated with an ultraviolet curable resin such as silicone to form an optical fiber wire, and a nylon-coated core wire having an outer diameter of 0.6 mm obtained by coating nylon around the optical fiber is further provided. It is preferably used.

The second and third tension members 22
a and 22b mainly connect the cable portion 20B to the support wire portion 20.
When the wiring is separated from A, the cable portion 20B bears strength so that the optical fiber core 23 is not disconnected. Also, when tapping the optical fiber 23,
The second and third tension members 22a, 22b
Used to pull the sheath 24 away from each other. In the present embodiment, a steel wire having an outer diameter of 0.4 mm is suitably used as the second and third tension members 22a and 22b in the present embodiment. The second tension member 22a is connected to the first tension member 21.
And on the same plane as the optical fiber core 23 and between the weakening groove 25 a and the optical fiber core 23. Further, the third tension member 22b is connected to the optical fiber core 23.
Is provided at a position opposed to the second tension member 22a with the. Second and third tension members 2
The distance between the center of the optical fibers 2a and 22b and the center of the optical fiber 23 can be changed as appropriate.

The first tension member 21 mainly bears the tensile strength when the overhead optical cable 20 is branched from the collective optical cable and wired overhead. In this embodiment, a steel wire having an outer diameter of 0.4 mm is suitably used.

The sheath 24 is connected to the first tension member 2
First, second and third tension members 22a, 22
b and the optical fiber 23 are integrated,
These are protected from mechanical external force during wiring and the environment after wiring. The sheath 24 is made of PVC or PE as a material.
Are preferably used, and are formed by extrusion coating.
Further, a lubricant is preferably added to the sheath 24. For example, erucylamide is preferably used as the lubricant,
The addition amount is preferably about 0.5 to 1%. It is preferable that the thickness of the sheath 24 is thinner because the diameter of the overhead optical cable 20 can be reduced. However, if the thickness is too thin, the first tension member 21 and the second tension member 22 are corroded,
The bending stiffness of the optical fiber 23 may be insufficient. Therefore, the cable portion 20B and the support wire portion 20
A so that these inconveniences do not occur even in a state where the optical fiber cable A is disconnected from the sheath A.
Is appropriately set.

The cross-sectional shape of the overhead optical cable 20 can be appropriately designed in consideration of the manufacturability and the like while ensuring the necessary thickness of the sheath 24. In the overhead optical cable 20 in this embodiment, the cross-sectional shape of the support wire portion 20A is a substantially circular shape with an outer diameter of 1.8 mm, and the cross-sectional shape of the cable portion 20B is a substantially elliptical shape with a short axis of 1.8 mm and a long axis of 2.6 mm. The thickness of the neck 25 in the cable width direction is formed to be 0.7 mm, the overall cable height is 6.1 mm, and the cable width is 1.8 mm. The depth of the weakening groove 25a provided in the neck 25 is 0.2 mm, and the depth of the weakening groove 26 provided in the vicinity of the optical fiber 23 is 0.2 m.
m.

In the overhead optical cable 20 having such a configuration, the first tension member 21, the second tension member 22a, the optical fiber 23, and the third tension member 22b are sequentially arranged on the same plane. It is obtained by applying an extrusion coating to form the sheath 24.

The collective optical cable of this embodiment can be manufactured as follows. First, a forming step of winding the connection groove 2 around the core member 1 while inserting an aerial optical cable into each of the grooves 3 of the connection groove 2, and thereafter, as shown in FIG. Is wound to form a press-winding layer 4 and a collective optical cable is obtained by a sheath forming step of extruding and covering the collective optical cable sheath 5 on the periphery of the connecting groove 2 on the side where the press-winding layer 4 is formed. The way of winding the connecting groove 2 around the core member 1 may be linear or spiral. As described above, the collective optical cable of the present embodiment can be manufactured in two steps of the forming step and the sheath forming step. In addition, since the above-described two steps can be performed continuously, manufacturing in one step is also possible.

The collective optical cable of the present embodiment obtained in this manner is used by being installed on a utility pole or the like. Then, a hole of an appropriate size is formed in the collective optical cable sheath 5 at a portion where the aerial optical cable 20 is extracted from the collective optical cable, thereby exposing the presser winding layer 4, and further removing the presser winding layer 4 to form a connection groove. A cut is made in the bottom plate 8 along the small groove 8a and the small groove 8b in which the bottom plate 8 is formed by using a blade, a hole of an appropriate size is formed in the bottom plate 8, and the overhead optical cable 20 is pulled out from the hole. This can be drawn into the subscriber's house and wired.

According to the collective optical cable of this embodiment, since a large number of overhead optical cables 20 are accommodated in one connecting groove 2, the accommodation density of the overhead optical cables 20 is high.
Higher density and smaller diameter of the collective optical cable can be achieved. Further, since the strip-shaped top plate 9a is formed on the top of the wall plate 9 of the connection groove 2, when the connection groove 2 is attached to the core member 1, the adjacent top plates 9a, 9a are fixed in close contact with each other. Since the wall plate 9 does not move, it is possible to prevent the overhead optical cable 20 from receiving a side pressure due to the movement of the wall plate 9. In addition, since the concave portion 9b is formed on the surface of the top plate 9a of the connection groove 2, the concave portion 9b of the top plate 9a fits on the outer periphery of the core member 1 when the connection groove 2 is attached to the core member 1. In close contact. Furthermore, since the small grooves 8a and 8b are formed in the longitudinal direction in the portion corresponding to the wall plate 9 on the bottom surface of the bottom plate 8 of the connecting groove 2, the portion where the small grooves 8a and 8b are formed is easy to bend. It is easy to attach the connecting groove 2 to the core member 1, and when the aerial optical cable 20 is branched from the collective optical cable, when the bottom plate 8 of the connecting groove 2 is cut open using a blade, the small grooves 8a and 8b serve as guide grooves for the blade. Since the blade can be reliably inserted into a predetermined position, it is possible to prevent the optical fiber core wire 23 from being erroneously damaged, thereby facilitating the branching operation.

Further, the method of manufacturing a collective optical cable according to the present embodiment requires fewer steps than the above-described conventional method of manufacturing a collective optical cable, and has good manufacturability. It is also possible to perform each step continuously, so that the production efficiency can be greatly improved.

The aerial optical cable 20 used in the present embodiment has a structure in which the supporting wire portion 20A and the cable portion 20B are integrated by the sheath 24, so that it is easy to manufacture and uses no bobbin or the like. It is possible to perform a winding bundle. Also, the support wire portion 20A and the cable portion 20B
Since the weakening groove 25a is provided between the support wire portion 20A and the support wire portion 20A, the cable portion 20B can be easily separated from the support wire portion 20A as necessary, and only the cable portion 20B can be used for wiring or the like. Further, if a lubricant is added to the sheath 24, the pull-out property of the overhead optical cable 20 is improved. Further, even when a plurality of overhead optical cables 20 are accommodated in one groove 3, the overhead optical cables 20 can be easily pulled out. Further, the second and third tension members 22
Since a and 22b are arranged at positions facing each other across the optical fiber core 23 and the sheath 24 on the circumference of the optical fiber core 23 is provided with a weakening groove 26,
The sheath 24 can be easily torn by pulling the second and third tension members 22a and 22b. Therefore, when the optical fiber 23 is connected, the optical fiber 23 can be easily led out without damaging the optical fiber 23 or applying a large bending stress.

In this embodiment, the connecting groove 2 has 12
Are formed, and the overhead optical cables 20 are accommodated one by one in these grooves 3. The number of the grooves 3 formed in the connecting groove 2 and the number of the overhead optical cables 20 accommodated in one groove 3 are formed. Can be any number, and at least one linking groove 2
It is sufficient that the overhead optical cable 20 is accommodated, and preferably about 1 to 24. In the present embodiment, a description has been given of the case where the core member 1 is one in which the PE (polyethylene) coating 7 is applied around the steel strand 6,
In addition, PBT (polybutylene terephthalate), P
A pipe made of C (polycarbonate), polyamide, or the like can also be used. In the present embodiment, the core member 1
The groove 3 is formed so that the contour of the groove 3 of the connecting groove 2 after winding is fan-shaped, but the shape of the groove 3 is not limited to this and can be changed as appropriate. Further, in the present embodiment, as the first example of the overhead optical cable housed in the groove 3 of the connecting groove 2, the one shown in FIG. 6 is used. Optical cables having various structures can be used as long as the optical cables can be wired overhead to a customer's house.

FIGS. 7 and 8 are sectional views respectively showing a second example and a third example of an overhead optical cable suitably used for the collective optical cable of the present invention. The overhead optical cable 10 shown in FIG. 7 includes a first tension member 11,
The second tension member 12 and the optical fiber core 13 are sequentially arranged on the same plane, and these are integrated by a sheath 14. This aerial optical cable 10 is significantly different from the aerial optical cable 20 of the first example in that the third tension member is not provided in the aerial optical cable 10, and
6 is the point attached vertically.

The aerial optical cable 10 has a cross section in a substantially gourd shape in which a support wire portion 10A having a substantially circular cross section and a cable portion 10B having a substantially circular cross section are connected via a neck portion 15. The neck portion 15 is provided with a weakening groove 15a in which a cut is made in the sheath 14 in the cable width direction, and the overhead optical cable 1 is located at the position of the weakening groove 15a.
0 can be easily cut in the cable width direction, that is, the direction along the line AA 'in FIG. By cutting the aerial optical cable 10 at this position, a support wire portion 10A composed of the first tension member 11 and the sheath 14, and a cable composed of the second tension member 12, the optical fiber core 13, and the sheath 14 are provided. The part 10B is separated. Further, a cord 16 is vertically attached to the optical fiber core 13, and a tear is formed in the sheath 14 by pulling the cord 16 so that the optical fiber 13 can be easily outputted therefrom. .

The optical fiber core 13, the first tension member 11, and the second tension member 12 are the same as those of the overhead optical cable 20 of the first example. In the overhead optical cable 10 of this example, the position where the second tension member 12 is provided is the first position.
Are on the same plane as the tension member 11 and the optical fiber
And can be changed as appropriate.

The sheath 14 is preferably made of PVC (polyvinyl chloride), PE (polyethylene), or the like, and is formed by extrusion coating, similarly to the overhead optical cable 20 of the first example. Also preferably, the first
The same sliding material as the overhead optical cable 20 of the example is added. The thickness of the sheath 14 is set in the same manner as in the overhead optical cable 20 of the first example. In the overhead optical cable 10 of this example, the cross-sectional shape of the support wire portion 10A has an outer diameter of 1.8 mm.
And the cross-section of the cable portion 10B has an outer diameter of 1.8.
mm, the thickness of the neck 15 in the cable width direction is 0.7 mm, the overall cable height is 4.0 mm, and the cable width is 1.8 mm. The depth of the weakening groove 15a provided in the neck 15 is 0.2 m.
m. It is desirable to use a material having a small diameter and relatively excellent strength, for example,
p-phenylene terephthalamide fiber (Kevlar: trademark)
And the like are suitably used.

In the overhead optical cable 10 having such a structure, the first tension member 11, the second tension member 12, and the optical fiber core 13 are sequentially arranged on the same plane, and the sheath 14 is formed by collectively extrusion coating. Is obtained. The overhead optical cable 10 of the second example
Since the lead cord is vertically attached to the optical fiber core 13, when connecting the optical fiber core 13, a tear is formed in the sheath 14 by pulling the lead fiber 16, and the optical fiber core 13 can be easily taken out.

The overhead optical cable 30 shown in FIG.
Tension member 31 and second tension member 3
2a, the optical fiber core wire 33, and the third tension member 32b are sequentially arranged on the same plane, and these are integrated by a sheath. The difference between the overhead optical cable 30 of this example and the overhead optical cable 20 of the first example is that the second and third tension members 32 are different.
a and 32b are both made of a nonmetallic material.

The aerial optical cable 30 of this example has a cross-sectional shape formed by connecting a support wire portion 30A having a substantially circular cross section to an end of a cable portion 30B having a substantially bow tie shape via a neck portion 35. ing. The neck portion 35 has a weakened groove 35 a formed by cutting a sheath 34 in a cable width direction.
Is provided. At the position of the weakening groove 35a, the overhead optical cable 30 is moved in the cable width direction, that is, C in FIG.
The support wire portion 30A including the first tension member 31 and the sheath 34 is easily cut in the direction along the line C '.
And second and third tension members 32a, 32b
And a cable portion 30B composed of the optical fiber core wire 33 and the sheath. The cable section 30B has a cross-sectional shape that is substantially bow-tie in which the cable width gradually decreases toward the central portion 35, and the optical fiber core 33 is disposed inside the central portion 36. The central portion 36 is provided with a weakening groove 36a in which a cut is made in the sheath 34 in the cable width direction. The sheath 34 is torn at the position of the weakening groove 36a, so that the optical fiber core wire 33 can be easily exposed. It has become.

The optical fiber core 33 and the first tension member 31 are the same as the overhead optical cable 20 of the first example. The second and third tension members 32a and 32b of the overhead optical cable 30 of this example are made of a non-metallic material, and are mainly used when the cable portion 30B is separated from the support wire portion 30A and wired. The cable portion 30B bears strength so as not to be disconnected. When the optical fiber core 33 is exposed, the second and third tension members 32a and 32b are used to pull the sheath 34 apart by pulling them away from each other. As the second and third tension members 32a and 32b, any suitable nonmetallic material can be used as long as the required strength is obtained. In this embodiment, FRP (glass fiber reinforced plastic) having an outer diameter of 0.7 mm is suitably used. The second and third tension members 32a,
The position where the 32b is provided is designed in the same manner as the overhead optical cable 20 of the first example.

The sheath 34 is preferably made of PVC (polyvinyl chloride) or PE (polyethylene) as a material, and is formed by extrusion coating, similarly to the overhead optical cable 20 of the first example. Also preferably, the first
The same sliding material as the overhead optical cable 20 of the example is added. The thickness of the sheath 34 is set in the same manner as in the overhead optical cable 20 of the first example. In the overhead optical cable 30 of this example, the cross-sectional shape of the support wire portion 30A has an outer diameter of 1.8 mm.
, The cross-section of the cable portion 30B is substantially bow-tie-shaped, and the cable width of the central portion 36 is 1.6 mm, and the portion having the largest cable width is 2.5 mm. The thickness of the neck 35 in the cable width direction is 0.7 m.
m, the overall cable height is 3.0m
m, and the cable width is 8.5 mm. Also neck 3
5, the depth of the weakening groove 35a formed in the central portion 36 of the cable portion 30B is 0.2 mm.
Has a depth of 0.2 mm.

In the overhead optical cable 30 having such a configuration, the first tension member 31, the second tension member 32a, the optical fiber core 33, and the third tension member 32b are sequentially arranged on the same plane. It is obtained by applying an extrusion coating to form the sheath 34.

In the overhead optical cable 30 of this example, since the second and third tension members 32a and 32b are made of a non-metallic material, when the cable portion 30B is routed from the collective optical cable to the indoor wiring, the cable 30B is not connected. There is an advantage that there is no risk of lightning damage even if the ground is not taken. Therefore, for example, from the branch point of the collective optical cable to the termination cabinet of the subscriber's house, an overhead optical cable 30 is used, and from this point to the indoor outlet, the support line 30A is separated and only the cable 30B is used for wiring. In addition, the optical fiber cable 33 can be pulled in from the collective optical cable to the indoor outlet without connection, and the diameter of the indoor wiring can be reduced.

[0042]

As described above, the collective optical cable of the present invention is formed by forming a large number of grooves by attaching connecting grooves to the core member and accommodating the overhead optical cables in these grooves. A large number of overhead optical cables can be accommodated in the groove, the accommodation density of the overhead optical cables is high, and the density and diameter of the collective optical cable can be reduced.

Further, since a band-shaped top plate is formed on the top of the wall plate of the connection groove, when the connection groove is attached to the core member, the adjacent top plates are fixed to each other in close contact with each other, and the wall plate is fixed. Does not move, so that it is possible to prevent the overhead optical cable from receiving a side pressure due to the movement of the wall plate. In addition, since the concave portion is formed on the surface of the top plate of the connecting groove, the concave portion of the top plate comes into close contact with the outer periphery of the core member when the connecting groove is attached to the core member. Furthermore, the small groove is formed in the portion corresponding to the wall plate on the bottom surface of the bottom plate of the connection groove in the longitudinal direction,
Since the portion where the small groove is formed is easy to bend, it is easy to attach the connecting groove to the core member, and when cutting the bottom plate of the connecting groove using a blade when branching the overhead optical cable from the collective optical cable, the small groove is used as a blade. Since it can be a guide groove, it is possible to reliably insert the blade at a predetermined position,
Inadvertent damage to the optical fiber can be prevented, and the branching operation is facilitated.

The collective optical cable according to the present invention includes two steps: a forming step of winding the connecting groove around the core member while inserting the aerial optical cable into the connecting groove, and a sheath forming step of forming the press-winding layer and the sheath. It is possible to manufacture in a process, the number of manufacturing steps is small, and the manufacturing efficiency is good. Further, by performing the above-mentioned two steps continuously, it is possible to manufacture in one step, and it is possible to greatly improve the manufacturing efficiency.

[Brief description of the drawings]

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

FIG. 2 is a perspective view showing a connecting groove before being attached to a core member.

FIG. 3 is an enlarged sectional view of a part of the connecting groove of FIG. 2;

FIG. 4 is an enlarged sectional view of a central portion of the collective optical cable of FIG.

FIG. 5 is a perspective view for explaining a production example of the collective optical cable of the present invention.

FIG. 6 is a cross-sectional view showing an overhead optical cable used for the collective optical cable of FIG.

FIG. 7 is a cross-sectional view showing another example of an overhead optical cable suitably used for the collective optical cable of the present invention.

FIG. 8 is a cross-sectional view showing another example of an overhead optical cable suitably used for the collective optical cable of the present invention.

FIG. 9 is a cross-sectional view showing an example of a conventional collective optical cable.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Core member, 2 ... Connecting groove, 3 ... Groove, 6
... Steel strand, 7 ... Coating, 8 ... Bottom plate, 8a, 8b ... Small groove, 9 ... Wall plate, 9a ... Top plate, 9b ... Recess, 10,2
0,30 ... overhead optical cable.

Claims (1)

[Claims] 1. An optical fiber cable for outdoor aerial assembly in which a number of grooves are formed by attaching a connecting groove to a core member, and an optical fiber outdoor optical cable is accommodated in these grooves.
The connection groove includes a band-shaped bottom plate, a plurality of wall plates erected on the bottom plate along the longitudinal direction thereof, and a band-shaped top plate formed on the top of the wall plate. Is an aerial assembly outdoor optical cable characterized in that a concave portion is formed, and a small groove is formed in a portion corresponding to the wall plate on the bottom surface of the bottom plate in the longitudinal direction.