JP5297514B2 - Flat optical fiber cable and optical fiber cable drawing method - Google Patents

Description

  The present invention relates to a flat optical fiber cable used for intra-building wiring in an apartment house, for example, and a method for drawing in the optical fiber cable.

  For example, in an existing apartment house such as an apartment, there may be no space for laying a new pipe for laying an optical fiber cable, or there may be no free space for laying an optical fiber cable in an existing pipe. is there.

  For this reason, it is necessary to route the optical fiber cable along the wall surface or ceiling surface of the common hallway from the dividing board installed at each level to each dwelling unit (each room). Examples of the optical fiber cable include a structure in which a plurality of indoor type optical fiber cables are connected through a connecting portion (for example, Patent Document 1), and a plurality of indoor type optical fiber cables together with a tension member. There is a structure (for example, Patent Document 2) that is covered and assembled.

JP 2008-70573 A JP 2008-281843 A

  However, in the optical fiber cable described in Patent Document 1, since the optical fiber cables are arranged in parallel by the connecting portion, it is difficult to tear the connecting portion while being fixed to the wall surface. In particular, in order to pull the branched optical fiber cable into the subscriber's house, it is necessary to take out a length of at least about 2 to 3 m. However, the connecting portion must be torn over this length range to separate the optical fiber cable. It must be difficult.

  On the other hand, in the optical fiber cable described in Patent Document 2, when the optical fiber cable is taken out from the inside by tearing the jacket, a plurality of optical fiber cables are arranged so as to surround the periphery of the tension member. It is difficult to find a specific optical fiber cable. Therefore, the installation cost increases because the extraction work of the optical fiber cable is required. Moreover, since the optical fiber cable of patent document 2 is circular shape, when it attaches to a wall surface, it looks bad.

  Accordingly, the present invention provides a flat optical fiber cable and an optical fiber cable lead-in that can be branched intermediately while being wired on a wall surface, and that each optical fiber cable can be easily identified at the time of intermediate branching. It aims to provide a method.

According to a first aspect of the present invention, a plurality of rectangular optical fiber cables formed by coating an optical fiber core wire with a sheath are arranged in a line, and a plurality of optical fiber cables are sandwiched between the both sides in the direction of the line. The tensile strength member is formed by covering a plurality of optical fiber cables and the tensile strength portions on both sides with an outer sheath. of the one surface of the long side to the side which is wired to the wall surface, the outer envelope surface opposite to the side to be wired to at least the wall surface, each notch at a position corresponding to the both sides of the strength member portion It is characterized by being formed in the longitudinal direction of the cable.

  2nd invention is 1st invention, Comprising: The melting | fusing point of the sheath of the said optical fiber cable is higher than the melting | fusing point of the said outer-layer jacket, It is characterized by the above-mentioned.

  3rd invention is 1st or 2nd invention, Comprising: The processus | protrusion provided in the side surface of the cable width direction among the said tension body parts of both sides melts with the heat | fever at the time of the coating | cover of the said outer-layer jacket, It is characterized by being fused to the outer envelope.

  A fourth invention is any one of the first to third inventions, characterized in that the total length of the optical fiber cable is longer than the total length of the flat optical fiber cable.

  5th invention is 4th invention, Comprising: The extra length ratio of the said optical fiber cable is 0.03% or more, It is characterized by the above-mentioned.

  A sixth invention is any one of the second to fifth inventions, characterized in that a friction coefficient of the sheath of the optical fiber cable is 0.3 or less.

  In the seventh invention, after the flat optical fiber cable according to any one of the first to sixth inventions is wired in contact with the wall surface, the notches formed in the outer layer jacket are each cut, The outer layer jacket of the portion where the cut is made is removed, the optical fiber cable is taken out from the inside and cut, and the notch formed in the outer layer jacket is cut at a position different from the portion where the cut is made. The optical fiber cable is characterized in that the outer layer jacket of the part where the cut is made is removed, the cut optical fiber cable is drawn out from the inside, and the drawn optical fiber cable is drawn into each room of the apartment house. It is a pull-in method.

  According to the present invention, a flat optical fiber cable in which a plurality of optical fiber cables are arranged in a line is formed. Therefore, since the outer shape is flat, it is easy to wire on a wall surface such as a shared corridor of an apartment house. Further, according to the present invention, since a plurality of optical fiber cables are arranged in a line, the arrangement is not changed in the longitudinal direction of the cable, and a specific optical fiber cable is identified in the arrangement order at the time of intermediate branching. be able to.

  Further, according to the present invention, since the outer layer jacket opposite to the side wired on the wall surface is provided with a notch at a position corresponding to the strength member, the flat optical fiber cable is wired on the wall surface. It is possible to remove the outer layer jacket and take out a specific optical fiber cable from the inside. That is, the intermediate branching operation can be performed even when the flat optical fiber cable is wired on the wall surface.

  Further, according to the present invention, the notch is formed at the position corresponding to the tensile strength body portion. Even if the notch is cut, the portion below the portion is the tensile strength body portion, so that the optical fiber cable is damaged. Can be prevented.

It is a cross-sectional view of the flat optical fiber cable of this embodiment. It is a schematic block diagram of the measuring apparatus used in measuring the friction coefficient between the optical fiber cables in the flat optical fiber cable of this embodiment. FIG. 3 is a view for explaining a method of taking out the specific optical fiber cable and drawing it into each room of the apartment house after the flat optical fiber cable of FIG. 1 is wired on the wall surface.

  Hereinafter, specific embodiments to which the present invention is applied will be described in detail with reference to the drawings.

  FIG. 1 shows a cross section of the flat optical fiber cable of this embodiment. This flat optical fiber cable 1 has a plurality of rectangular optical fiber cables 4 formed by coating an optical fiber core wire 2 with a sheath 3 arranged in a line (in parallel), and a tension member 5 is coated on both sides of the cable. 6 is disposed, and the plurality of optical fiber cables 4 and the tensile strength body portions 7 on both sides are collectively covered with the same outer layer jacket 8 to form a flat cable. ing. This flat optical fiber cable 1 is suitable for wiring a specific optical fiber cable 4 to each room by wiring on a wall surface (such as a ceiling wall or an eaves wall surface) such as a shared corridor in an apartment house such as an existing apartment. It is.

  The optical fiber cable 4 has an optical fiber core 2 provided at the center and two tension members 9 and 9 arranged on both sides of the optical fiber core 2 so as to be spaced apart from each other on the same straight line. Thus, the rectangular cross-sectional shape is integrally covered with the sheath 3.

  The optical fiber core wire 2 is composed of, for example, a quartz glass fiber provided in the center and an outer layer formed by coating the ultraviolet curable resin around the quartz glass fiber. The optical fiber core 2 has a standard in which the outer diameter of the silica glass fiber is 0.125 mm and the entire outer diameter is 0.25 mm. Further, the outer layer of the optical fiber 2 is colored (including colorless) for distinguishability between the cores.

  The two tension members 9 and 9 are disposed on both sides of the optical fiber core 2 so as to be separated from each other. These tension members 9 and 9 are provided on the same line as the optical fiber core wire 2 provided at the center position of the optical fiber cable 4. The tension members 9 and 9 function as a cable rigid member that increases the rigidity of the optical fiber cable 4 itself and as a cable bending direction regulating member that curves the bending direction of the optical fiber cable 4 only in the cable short side direction. In this embodiment, aramid FRP of φ0.5 mm is used as the tension members 9 and 9. The tension members 9, 9 can be made of, for example, various fiber reinforced plastics such as glass FRP, steel wires, or the like other than the aramid FRP which is easily bent to a small diameter.

  The sheath 3 is formed with notches 10 and 11 for tearing the sheath 3 and taking out the optical fiber core wire 2. The notches 10 and 11 are each formed as a groove having a V-shaped cross section that tapers toward the optical fiber core 2 at a position corresponding to the optical fiber core 2. These notches 10 and 11 are formed continuously along the longitudinal direction of the cable (direction perpendicular to the paper surface of FIG. 1).

  For the sheath 3, for example, black flame-retardant polyethylene in which magnesium hydroxide and red phosphorus are mixed with high-density polyethylene can be used. In addition, various olefinic materials such as low density polyethylene, linear low density polyethylene, medium density polyethylene, ethylene vinyl acetate copolymer (EVA), ethylene / ethyl acrylate copolymer (EEA), and additives such as flame retardants. The flame retardant polyolefin contained can also be used as the sheath 3.

  In addition, the melting point of the sheath 3 is higher than the melting point of the outer envelope 8 described later. By doing so, it is possible to prevent the sheath 3 and the outer layer jacket 8 from being fused by heat when the optical fiber cable 4 and the strength member 7 are collectively covered with the outer layer jacket 8. In the present embodiment, high-density polyethylene is used as the base resin of black flame-retardant polyethylene as the sheath 3 that is higher than the melting point of the outer envelope 8.

  In this embodiment, the outer diameter of the optical fiber cable 4 is set to 1.6 mm (vertical) × 2.0 mm (horizontal). The size of the optical fiber cable 4 can be adapted to existing connectors by making it the same shape and the same size as the existing indoor cable used conventionally. Of course, the present invention is not limited to the above dimensions.

  Further, the friction coefficient of the sheath 3 is set to 0.3 or less. By doing so, the specific optical fiber cable 4 to be pulled out of the plurality of optical fiber cables 4 arranged in contact with each other can be easily taken out from the other optical fiber cables 4. In order to make the friction coefficient of the sheath 3 0.3 or less, for example, a resin having a high surface hardness such as high-density polyethylene and a low friction coefficient is used, and a lubricant such as silicone-dispersed polyethylene, silicone blend polyethylene, and fatty acid amide is added. This can be reduced. In order to make it easy to take out the optical fiber cables 4 at both ends, it is desirable that the outer cover 6 of the strength member 7 also has a friction coefficient of 0.3 or less. The reason why the friction coefficient is set to 0.3 or less will be described in an example described later.

  The total length of the optical fiber cable 4 is longer than the total length of the flat optical fiber cable 1. Specifically, the extra length ratio of the optical fiber cable 4 is set to 0.03% or more. The extra length ratio is expressed by ((total length of optical fiber cable−total length of flat optical fiber cable) / total length of flat optical fiber cable) × 100%. By making the total length of the optical fiber cable 4 longer than the total length of the flat optical fiber cable 1, the optical fiber cable 4 is slightly lifted when part of the outer sheath 8 is peeled off during intermediate branching. It becomes easy to take out. The reason why the surplus length ratio is set to 0.03% or more will be described in an example described later.

  The extra length is such that when the optical fiber cable 4 and the strength member 7 are arranged in parallel in a row and inserted into the extrusion head for extruding the outer sheath 5, the strength member 7 extends more than the optical fiber cable 4. By applying a tension so as to be, a plus extra length can be obtained. By doing in this way, the extra length ratio of the optical fiber cable 4 can be 0.03% or more.

  In FIG. 1, the number of the optical fiber cables 4 is four, and the optical fiber cables 4 are brought into contact with each other and arranged in a line. All of the four optical fiber cables 4 have the same shape and the same outer shape.

  The strength member 7 is formed in a rectangular shape by covering the strength member 5 provided at the center with the outer cover 6. In view of the ease of alignment when the tensile strength body portion 7 is inserted into an extrusion head for extruding the outer layer jacket 8, the vertical and horizontal sizes are substantially the same as those of the optical fiber cable 4. When the strength member 7 has the same size as that of the optical fiber cable 4, the thickness becomes uniform when viewed as a whole of the flat optical fiber cable, and it is easy to wire the wall surface.

  In the present embodiment, the tensile strength body portion 7 is formed by using an iron wire having a diameter of 0.5 mm as the tensile strength body 5 and covering it with the same black flame-retardant polyethylene as the sheath 3 of the optical fiber cable 4 to form the jacket 6. . Further, the tensile strength body portion 7 has a rectangular shape of 1.6 mm in length and 2.0 mm in width like the optical fiber cable 4. In addition, the dimension of the said tension body part 7 is an example, and is not limited to this. The tensile strength body portion 7 has a rectangular cross-sectional shape perpendicular to the longitudinal direction, but a shape that is not in contact with the optical fiber cable 4 may have a rounded arc shape. In addition, the strength member 7 may have a circular or elliptical cross-sectional shape, and is not particularly limited to the shape.

  As the tensile body 5, various fiber reinforced plastics such as aramid FRP and glass FRP, and steel wires can be used in addition to iron wires. When wiring to the wall of a shared corridor (passage) in a condominium, the cable can be bent easily by using a metal material that is easily plastically deformed, such as an iron wire. It becomes possible to wire neatly.

  It is desirable that the jacket 6 of the strength member 7 is formed of the same material as the sheath 3 of the optical fiber cable 4. Specifically, the jacket 6 is formed of a material in which the melting point of the outer cover 6 of the strength member 7 is higher than the melting point of the outer cover 8 and the friction coefficient of the outer cover 6 is 0.3 or less. Since the specific material is the same as that of the sheath 3 of the optical fiber cable 4, the description thereof is omitted here. If the outer sheath 6 of the strength member 7 is made of the same material as the sheath 3 of the optical fiber cable 4, the outer layer sheath 8 is peeled off at the time of intermediate branching, and the optical fiber cables 4 at both ends contacting the strength member 7 are taken out from the inside. Work becomes easy. In other words, the removal of the optical fiber cable 4 is facilitated by both the fact that the outer sheath 8 and the tensile body portion 7 are not fused and the sliding of the optical fiber cable 4 with respect to the tensile body portion 7 is improved. .

  Further, the protrusion 12 provided on the side surface 6 a in the cable width direction of the tensile strength body portion 7 is melted by heat at the time of covering the outer layer jacket 8 and is fused to the outer layer jacket 8. In FIG. 1, the protrusion 12 is illustrated, but actually, the protrusion 12 melts at the time of heat-sealing with the outer layer jacket 8, and the outer shape of the protrusion 12 cannot be understood. The protrusion 12 is formed as a protrusion having a triangular shape with the tip sharpened from the side surface 6 a of the outer cover 6 toward the outside. If the projections 12 are provided, the outer layer jacket 8 and the jacket 6 of the strength member 7 are fused, so that the strength member 5 can be prevented from protruding or retracting.

  In the present embodiment, three protrusions 12 are provided. In addition, the projections 12 are similarly provided on the long sides 6b and 6c. The protrusions 12 provided on the both surfaces 6b and 6c are provided at positions closer to the side surface 6a than the center position where the strength member 5 is provided. At this position, the optical fiber cable 4 can be taken out when the outer jacket 8 is peeled off from a notch described later.

  The outer-layer jacket 8 includes a wall-side outer-layer jacket that contacts the wall surface 13 (hereinafter referred to as a wall-surface-side outer jacket 8a) and a surface-side outer layer jacket that does not contact the wall surface 13 (hereinafter referred to as the surface side). And outer side envelopes (hereinafter referred to as side-side outer envelopes 8c and 8d) corresponding to the tensile strength body portions 7 at both ends.

  The outer layer jacket 8 is formed by extrusion molding so as to cover a plurality of optical fiber cables 4 arranged in a row and the tensile strength body portions 7 on both sides. At this time, the outer layer jacket 8 is coated so as not to be bonded to the optical fiber cable 4 by thermal fusion so that the outer layer jacket 8 can be cut off and the optical fiber cable 4 mounted inside can be taken out. Yes. This is realized because the melting point of the sheath 3 of the optical fiber cable 4 is higher than the melting point of the outer sheath 8.

  For the outer sheath 8, a black flame-retardant polyolefin containing EEA as a base material and containing magnesium hydroxide and red phosphorus was used. In addition, various olefin materials such as low density polyethylene, linear low density polyethylene, medium density polyethylene, ethylene vinyl acetate copolymer (EVA), ethylene / ethyl acrylate copolymer (EEA), and additives such as flame retardants are added to them. A flame retardant polyolefin can be used. In order to avoid fusion with the sheath 3 of the optical fiber cable 4 and to facilitate tearing at the notch described later, a resin such as low density polyethylene, EEA, EVA, and an additive such as a flame retardant are added thereto. A flame retardant polyolefin is desirable.

  On the opposite side of the outer layer jacket 8 from the side wired to the wall surface 13, notches 14 are respectively formed in the cable longitudinal direction at positions corresponding to the tensile strength body portions 7 on both sides. Specifically, a notch 14 is formed in the longitudinal direction of the cable as a V-shaped groove that tapers toward the strength member 5 at a position corresponding to each strength member 7 in the outer surface outer layer jacket 8b. Yes. Similarly, a notch 14 is formed in the longitudinal direction of the cable as a V-shaped groove tapering toward the strength member 5 at a position corresponding to each strength member 7 in the wall surface outer layer jacket 8a. These notches 14 are provided outside the portion where the optical fiber cables 4 are arranged in parallel. It is desirable from the removability of the outer envelope 8 that the outer envelope 8 and the outer envelope 6 are not fused below the notch 14. In this embodiment, the notch 14 is formed in both the wall surface side outer layer jacket 8a and the surface side outer layer jacket 8b. However, the notch 14 may be provided only in the surface side outer layer jacket 8b.

  According to the flat optical fiber cable 1 configured as described above, a flat optical fiber cable in which a plurality of the optical fiber cables 4 and the tensile strength member portions 7 on both sides are arranged in a line is formed, so that the outer shape is flat. Because of this, it is easy to wire the walls such as the shared corridor of the apartment. Further, according to the present invention, since the plurality of optical fiber cables 4 are arranged in a line, the arrangement thereof is not changed in the longitudinal direction of the cable, and the specific optical fiber cables 4 are arranged in the arrangement order at the time of intermediate branching. Can be identified. In addition, the discriminability of the optical fiber cable 4 is further improved by performing identification printing such as numbering on the surface of the sheath 3 of the optical fiber cable 4.

  Further, according to the flat optical fiber cable 1, the notch 14 is provided in the outer layer jacket 8 on the side opposite to the side wired on the wall surface 13 at a position corresponding to the tensile strength body portion 7. Therefore, the flat optical fiber Even in a state where the cable 1 is wired on the wall surface 13, the outer layer jacket 8 can be peeled off and the specific optical fiber cable 4 can be taken out from the inside. That is, the intermediate branching operation can be performed even when the flat optical fiber cable 1 is wired to the wall surface 13.

  Moreover, according to this flat optical fiber cable 1, since the notch 14 is formed in the position corresponding to the strength body part 7, even if this notch 14 is torn, the part below the part is the strength body part 7. The optical fiber cable 4 can be prevented from being damaged.

  Further, according to the flat optical fiber cable 1, the melting point of the sheath 3 of the optical fiber cable 4 is set higher than the melting point of the outer layer jacket 8, so that the sheath 3 and the outer layer jacket 8 are bonded (fused). The outer layer jacket 8 can be easily peeled off at the time of intermediate branching. For this reason, since the outer layer jacket 8 is peeled off without disturbing the arrangement state of the optical fiber cables 4, it is easy to take out the specific optical fiber cable 4 from the inside.

  Further, according to the flat optical fiber cable 1, the protrusions 12 provided on the side surfaces 6 a in the cable width direction of the tensile body portions 7 on both sides are melted by the heat at the time of covering the outer layer jacket 8, and the outer layer jacket Since it is fused with 8, it is possible to prevent the tensile body 5 from protruding and retracting.

  Moreover, according to this flat optical fiber cable 1, since the total length of the optical fiber cable 4 is longer than the total length of the flat optical fiber cable 1, the excess optical fiber cable 4 is slightly removed at the portion where the outer layer jacket 8 is removed. The optical fiber cable 4 can be easily pulled out even when attached to the wall surface 13.

  The following experiment was conducted on the reason why the extra length ratio of the optical fiber cable 4 in the flat optical fiber cable 1 is 0.03% or more. The extra length ratio was measured as follows. After measuring and cutting the flat optical fiber cable 1 to a length of 10 m, the outer jacket 8 was peeled off, the optical fiber cable 4 was taken out from the inside, and the length of the taken-out optical fiber cable 4 was measured. When the length of the optical fiber cable 4 at this time is L1, and the total length of the flat optical fiber cable 1 is L0 = 10 m, the extra length ratio = ((L1-L0) / L0) × 100%.

Table 1 shows the result of confirming the extra length ratio of the optical fiber cable 4 and the take-out property of the optical fiber cable 4 at the time of intermediate branching. In the intermediate branching operation, the optical fiber cable 4 was attached to a flat surface, and the outer layer jacket 8 was removed by making a cut in the notch 14 over a length of 15 cm at the middle of the cable. In this state, the optical fiber cable 4 was slackened and evaluated as ◯ for those that could be easily taken out, Δ for those that could be taken out, and x for those that could not be taken out.

  As a result, it was confirmed that an intermediate branching operation is possible if the extra length ratio is 0.03% or more. Furthermore, the extra length ratio of 0.05% or more is excellent in the takeout property of the optical fiber cable 4, and this range is desirable.

  Moreover, the following experiment was conducted about the reason why the friction coefficient of the sheath 3 of the optical fiber cable 4 in the flat optical fiber cable 1 described above was 0.3 or less. The friction coefficient of the sheath 3 (including the outer cover 6 of the strength member 7) was measured by the method shown in FIG. The optical fiber cables 4 are arranged in a row and fixed to the flat plates 15 and 16 respectively, and the pulling force when the optical fiber cable 4 sandwiched between them is pulled at a pulling speed of 500 mm / min is measured. The optical fiber cable 4 was attached to the flat plates 15 and 16 with double-sided tape.

A weight 17 was placed on the upper flat plate 16 so that a load of 19.6 N was applied. When the pulling force is F (N), the friction coefficient μ = F / 19.6. Then, the friction coefficient and the drawability of the optical fiber cable 4 were investigated. For the drawability, the optical fiber cable 4 was attached to a flat surface, and a notch 14 was cut over a length of 15 cm at the middle portion of the cable to remove the outer layer jacket 8 (point a). A similar outer layer jacket 8 was removed at a position 3 m away from the jacket removing portion, and one optical fiber cable 4 was cut (point b). The optical fiber cable 4 cut at the point b was pulled from the point a, and it was confirmed whether or not the optical fiber cable 4 was pulled out. The results are shown in Table 2.

  As can be seen from this result, it was confirmed that the optical fiber cable 4 could be easily pulled out by 3 m or more if the friction coefficient of the sheath 3 was 0.3 or less. 3 m is a length necessary for drawing the optical fiber cable 4 from the hallway to each room.

  Thus, if the friction coefficient of the sheath 3 of the optical fiber cable 4 is 0.3 or less, the friction between the adjacent optical fiber cables 4 becomes small, and the sheath 3 and the outer layer jacket 8 are fused. Therefore, the optical fiber cable 4 can be easily pulled out from the inside. As a result, when the optical fiber cable 4 is pulled out 2 m at the time of the intermediate branch, the outer layer jacket 8 is peeled off from the intermediate branch 2 m below, and the optical fiber cable 4 to be branched at this portion is cut, thereby The 2 m optical fiber cable 4 can be pulled out from the branch part. By doing so, it is possible to secure the optical fiber cable 4 having a length necessary for drawing into each room while minimizing the length for removing the outer sheath 8.

[How to pull in optical fiber cable]
Next, a method of drawing the specific optical fiber cable 4 into each room of the apartment house after wiring the flat optical fiber cable 1 in contact with the wall surface 13 will be described. FIG. 3 is a view for explaining a method of taking a specific optical fiber cable 4 from the flat optical fiber cable 1 of FIG. 1 and drawing it into each room.

  The flat optical fiber cable 1 is wired by a cable fixing means 18 on a wall surface such as a corridor of an existing apartment house such as an apartment. In order to draw a specific optical fiber cable 4 from the flat optical fiber cable 1 into each room, a notch 14 in an arbitrary cable part A is cut with a cutter. At this time, since the strength member 7 is located directly below the notch 14, the optical fiber cable 4 is not accidentally damaged.

  Then, the outer layer jacket 8 of the arbitrary cable part A with the cut is peeled off by a predetermined length, and the specific optical fiber cable 4 is taken out from the inside and cut. Further, a cut is made at a position different from the arbitrary cable part A with the cut. The cable part B which is the position where the second cut is made is a part corresponding to the room into which the optical fiber cable 4 is drawn. The distance between the first cut site A and the second cut site B is the length necessary to pull into the room.

  Next, the outer layer jacket 8 of the second cut portion B is peeled off by a predetermined length, and the cut optical fiber cable 4 is pulled out from the inside. Then, the drawn optical fiber cable 4 is drawn into a predetermined room. Thereafter, the cable portions A and B having the cuts are covered with some cover, or tape is applied to cover the torn portions. The above work is performed for each room.

  According to this drawing method of the optical fiber cable, the specific optical fiber cable 4 can be taken out by making a cut in the notch 14 formed in the outer jacket 8 while the flat optical fiber cable 1 is wired on the wall surface 13. it can. For this reason, the operation of drawing the optical fiber cable 4 into each room can be performed in a short time, and the cost required for the laying operation can be greatly reduced.

  Although specific embodiments to which the present invention is applied have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made. For example, in this embodiment, the optical fiber core wire 2 is provided at the center, tension members 9 and 9 are disposed on both sides thereof, and the indoor optical fiber cable 4 is covered with the sheath 3. The invention is not limited to this form of optical fiber cable.

  INDUSTRIAL APPLICABILITY The present invention can be used for a flat optical fiber cable used for premises wiring in an apartment house and drawn into each room.

DESCRIPTION OF SYMBOLS 1 Flat optical fiber cable 2 Optical fiber core wire 3 Sheath 4 Optical fiber cable 5 Tensile body 6 Outer sheath 7 Tensile body part 8 Outer layer outer sheath 12 Protrusion 13 Wall surface 14 Notch

Claims (7)

A plurality of rectangular optical fiber cables formed by coating optical fiber cores with a sheath are arranged in a line, and a tensile body is attached to both sides of the plurality of optical fiber cables in the direction of the line. A tensile strength body portion coated with a covering is disposed, and the plurality of optical fiber cables and the tensile strength portion portions on both sides are collectively covered with an outer sheath, and the long side of the outer sheath is formed . one surface and the side which is wired to the wall surface, the outer envelope surface opposite to the side to be wired to at least the wall surface, the corresponding cable longitudinal notch in positions with strength members of both sides A flat optical fiber cable characterized by being formed into The flat optical fiber cable according to claim 1,
A flat optical fiber cable, wherein a melting point of the sheath of the optical fiber cable is higher than a melting point of the outer layer jacket. The flat optical fiber cable according to claim 1 or 2,
A flat optical fiber cable in which protrusions provided on side surfaces in the cable width direction of the tensile strength body portions on both sides are melted by heat at the time of coating the outer layer jacket and fused to the outer layer jacket. . A flat optical fiber cable according to any one of claims 1 to 3,
A flat optical fiber cable, wherein an overall length of the optical fiber cable is longer than an overall length of the flat optical fiber cable. The flat optical fiber cable according to claim 4,
A flat optical fiber cable, wherein an extra length ratio of the optical fiber cable is 0.03% or more. A flat optical fiber cable according to any one of claims 2 to 5,
A flat optical fiber cable, wherein a coefficient of friction of the sheath of the optical fiber cable is 0.3 or less. After wiring the flat optical fiber cable according to any one of claims 1 to 6 in contact with a wall surface,
Cut into the notches formed in the outer jacket, respectively, remove the outer jacket of the portion where the cut was made, take out the optical fiber cable from the inside and cut,
Further, the notch formed in the outer layer jacket is cut at a position different from the notched portion, the outer layer jacket of the cut portion is removed, and the optical fiber cable cut from the inside is removed. A method of drawing a flat optical fiber cable, characterized in that the optical fiber cable is pulled out and drawn into each room of the apartment house.

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