JP5250592B2 - Fiber optic cable - Google Patents

Description

  The present invention relates to an optical fiber cable.

  An optical fiber cable is provided in the underground conduit or between the power poles on the ground, and is drawn into the building, condominium, or house from the power pole.

  In recent years, with the spread of the Internet, FTTH (Fiber To The Home) optical fiber cables that provide high-speed and large-capacity communication have become widespread. From the viewpoint of laying the optical fiber cable, reducing the cost of drawing it in, and restricting the optical fiber laying pipeline, branch the optical fiber core from the middle of the optical fiber cable containing a plurality of optical fiber cores, Many wiring forms connected to a plurality of terminals are employed. These branching operations are normally performed in a live line state without interrupting signal transmission, and the optical fiber cable is required to have a simple configuration that does not cut the optical fiber core wire. Various proposals have been proposed to meet this demand.

  In Patent Document 1, the cable jacket is not bonded and integrated to both sides of the optical fiber core on the side where no tension member is arranged, and is wider than the arrangement width of the optical fiber core. An optical fiber cable is described in which a synthetic resin release tape is disposed so as to be in contact with the fiber core.

  Patent Document 2 describes an optical fiber cable in which a plurality of optical fiber core wires are accommodated in a gap in a covering resin body of a cable body.

JP 2008-70601 A JP 2004-361475 A

  The optical fiber cable described in Patent Document 1 is arranged on both sides of a plurality of optical fiber cores so that the peeling tape is in contact with the optical fiber cores, and the optical fiber cores are sheaths, that is, cables. It is covered with a jacket.

  As this release tape, a tape made of a synthetic resin made of a material that has poor adhesion to the cable jacket and easily peels off is used.

  The method of taking out the internal optical fiber core from the optical fiber cable having the above-described configuration is as follows. First, the cutting blade is bitten into the notch, cut toward the tape, and the cable jacket is divided into two divided portions on the end side and It is configured by dividing into four of the two divided parts on the side surface side. Even if the peeling tape is not adhered to the cable jacket or has been adhered, the peeling tape has a weak adhesive force, so that it can usually be easily separated into four divided portions.

  When separating the optical fiber cores in this way, the peeling tape comes out together with the optical fiber core wires. There is a risk of cutting the optical fiber. In addition, there is a problem that the manufacturing cost becomes high because the release tape is contained.

  In the thing of patent document 2, it has the structure which provided the space | gap part in the coating resin body of the cable main body, and accommodated the several optical fiber core wire in this space | gap part, and the tape is used. Absent.

  However, the optical fiber core is held through the fiber inclusions embedded in the air gap, and there is a risk of cutting the optical fiber core wire when removing the fiber inclusions in an intermediate branching operation. In addition, the optical fiber core wire is not directly formed by the surrounding cable jacket, and there is a problem in holding.

  The present invention has been made in view of such points, and reliably holds the optical fiber core by the cable jacket, and without using a material that may cut the optical fiber core during the intermediate branching operation. Furthermore, it aims at providing the optical fiber cable which can aim at the cost reduction at the time of manufacture by this.

The present invention has a cable portion provided with a substantially rectangular sheath having a long side and a short side to accommodate one or more optical fiber cores, and one or more cables are provided on both sides of the long side of the cable portion. In an optical fiber cable with a notch,
The optical fiber core wire is held in contact with and sandwiched by the cable jacket,
The gap is on the long side cross section including the notch, and is formed inside the cable jacket so as to contact through a contact opening that opens to a part of the optical fiber core. The contact area of the mouth with the one or more optical fiber cores is made smaller than the projected cross-sectional area of the optical fiber cores, and the drop of the optical fiber cores into the gap is caused by the cable jacket An optical fiber cable characterized by being blocked is provided.

  The present invention is also characterized in that, in claim 1, the notches are formed on both sides of the side surface of the long side at a symmetric position about the center line along the long side, and the gap is formed between both notches. An optical fiber cable is provided.

The present invention is also the optical fiber according to claim 1, wherein the plurality of optical fiber core wires are arranged in two rows in the vertical direction along the side surface of the long side, and the gap portion is at the end of each row. Provided is an optical fiber cable which is arranged in two rows and two columns so as to be in contact with a side surface on the long side of the core wire.
According to the present invention, in the first aspect, the plurality of optical fiber cores are arranged in two rows in the vertical direction along the side surface on the long side, and the gap portion is defined by the width of the optical fiber core in each column. Is formed in a large width so as to be in open contact with the short side surface of the two optical fiber cores at the end of each row, and the contact area of the contact port to the two optical fiber cable cores is An optical fiber cable characterized by being made smaller than the maximum projected cross-sectional area of an optical fiber core.

  According to the present invention, in the first aspect, the plurality of optical fiber cores are arranged in two rows in the vertical direction along the long side surface, and the gap is smaller than the width of the optical fiber core in each column. The contact area of the contact opening to one optical fiber cable core wire is formed so as to be in open contact with the short side surface of the two optical fiber core wires formed at the end of each row. An optical fiber cable characterized by being smaller than the maximum projected cross-sectional area of the fiber core is provided.

  In the present invention, since the gap portion is formed as described above, the drop of the gap portion of the optical fiber core wire is prevented, so that the optical fiber core wire is securely held by the cable jacket and the intermediate branch. This makes it possible to reduce the manufacturing cost without using a material that may cut the optical fiber core wire during operation.

The longitudinal cross-sectional view which shows the structure of the Example of this invention. The longitudinal cross-sectional view which shows the other structure of this invention. The longitudinal cross-sectional view which shows the other structure of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a longitudinal sectional view showing a configuration of an optical fiber cable 100 according to an embodiment of the present invention.

  In FIG. 1, an optical fiber cable 100 includes a branch line portion 1 and a cable portion 2, and both are connected by a neck portion 3. In this example, the branch line part 1 connected through the neck part 3 is provided, but the present invention is applied to an example in which the branch line part 1 is not provided.

  A tensile body 11 is provided at the center of the branch line portion 1, a sheath 12 is applied to the outer periphery thereof, and a cable jacket is formed.

  The cable portion 2 includes a cable jacket having a substantially rectangular shape with a long side 21 and a short side 22, that is, a sheath 14, an optical fiber core 13 and a pair of upper and lower strength members 15 accommodated therein, and further an optical fiber core. 13, the gap portion 16 is formed around the periphery of the cable portion 2, and two notches 17 are formed on both sides of the long side surface of the cable portion 2.

  In the present embodiment, the strength member 15 is provided in the cable portion 2, but the present invention can also be applied to an example in which the strength member 15 is not provided. Further, in this embodiment, two notches 17 are provided on both sides of the long side surface of the cable portion 2, but the present invention is not limited to this. What is necessary is just to set with the part 16 formation condition.

  In the present embodiment, a plurality of (four in the drawing) optical fiber core wires 13 are arranged in two rows in the vertical direction (both short side directions) along the long side surface, and the total Eight optical fiber core wires are accommodated in the cable portion 2.

  Each optical fiber core wire 13 is held in contact with the cable jacket 14 and is pressed and held.

  In this example, four gap portions 16 are arranged in parallel in two rows and two columns so as to mainly contact the side surface on the long side of each optical fiber core wire 13 at the end of each column. In this example, the gap 16 is mainly in contact with the side surface on the long side of the optical fiber core wire 13, but may be mainly in contact with the side surface on the short side, You may make it contact on both sides equally.

  In this example, the length of the gap portion 16 in the vertical direction is made shorter and longer depending on the arrangement so that the optical fiber core wire 13 is displaced in the vertical direction, that is, in a zigzag manner.

  The notches 17 are formed at positions where the respective gaps 16 are located when the long side is cut in the horizontal direction (long side cross section). Such a state is indicated by dotted lines A and B in the drawing. When the cable jacket 14 is cut by cutting the notch 17 into the notch 17, the cut line can easily reach each gap 16. ing. In other words, the gap 16 is formed on the long side cross section including the notch 17.

  The gap portion 16 is arranged so as to open and contact the optical fiber core wire 13, and the contact portion is a contact port 23, and the gap portion 16 has a notch shape.

  The contact area of the contact opening 23 of the gap 16 in the open state with respect to the optical fiber core wire is smaller than the projected cross-sectional area of the optical fiber core wire 16 toward the contact opening 23. Considering that the optical fiber core wire 16 has a circular shape, the cross-sectional area formed by the contact edge of the cable jacket 14 forming the contact port 23 is smaller than the cross-sectional area of the central portion of the optical fiber core wire 16. That is, it is narrow.

  With such a contact hole configuration, the optical fiber core wire 16 in contact with the contact hole 23 is prevented from moving (shifting) and falling into the gap portion 16. That is, the cable jacket contact edge, which is the surrounding cable jacket 14 forming the contact port 23, functions to prevent the optical fiber core wire 13 from dropping into the gap 16. Therefore, even if the gap 16 is formed in this way, the function of the cable jacket 14 to hold the optical fiber core wire 16 by pressing is not hindered.

As described above, the gap portion 16 is formed inside the cable jacket so as to be in contact with a part of the optical fiber core wire 16 via the contact port 23, and is made smaller than the projected sectional area of the contact port 23. Thus, the drop of the optical fiber core wire 13 into the gap 16 is prevented by the cable jacket itself.
These functions are the same for any of the four gaps 16.

The optical fiber core wire 16 is taken out from the inside of the optical fiber cable 100 configured as described above as follows.
First, the branch line portion 1 and the cable 2 portion are separated at the neck portion 3.
Next, a cutting blade (not shown) is bitten into the notch 17.

  In such a state, a cut is made from each notch 17 toward each gap portion 16, and the cut is made to reach the gap portion 16. As a result, in the cable part 2 that is cut by the cutting blade, the cable jacket 14 is divided into four parts, that is, a split part on the end part side and a split part on the side face side.

  The optical fiber core wire 13 and the cable jacket 14 are in contact with each other on at least one side surface. For this reason, it is possible to easily take out the optical fiber core 13 and cut the optical fiber core 13 without giving any instantaneous loss fluctuation or bending to the internal optical fiber core 13 and since there is no material that disturbs the cutting. Absent. The optical fiber fiber cable has an optical fiber core wire pulling force of 10 N or more with respect to 10 cm of the optical cable core wire. Holding power is kept.

  For the optical fiber 13, it is preferable to use a coating material that has poor adhesion to the cable jacket 14 and can be easily peeled off.

  According to the present embodiment, as a result of performing an intermediate branching operation using an intermediate branching tool such as a conventional cutting blade of an optical fiber cable, the operation can be performed without performing the removal work of inclusions such as a peeling tape, and the active state During this branching operation, there was no instantaneous loss fluctuation or increase in loss due to bending in the optical fiber core 13, and the optical fiber core 13 was not cut.

  FIG. 2 shows a second embodiment of the present invention. The same components as those in the first embodiment shown in FIG. 1 are denoted by the same reference numerals, and the description thereof will not be made in the first embodiment. The explanation which was made is used.

  In this embodiment, two gaps 16 are formed on the upper and lower sides of the short side 22. The optical fiber core wires 13 arranged in two rows are arranged on the same cross section.

  The width in the long side direction of the end face of the gap portion 16 is formed larger than the width of the optical fiber core wires 13 in each row.

  The gap 16 is in contact with the short side surface of the two optical fiber core wires 13 at the end of each row. The contact port 23 is in contact with two optical fiber cable cores that are in contact with each other in the same cross section, and the contact area is smaller (narrower) than the maximum projected cross-sectional area of the optical fiber core wire 13.

  In this example, the neck portion 24 is formed in the gap portion 16. However, the neck portion 24 may be linear in the vertical direction, but it is not desirable to be inclined outward from the linear shape.

  Even with such a structure, the same effect as in the first embodiment can be obtained.

  FIG. 3 shows a third embodiment of the present invention. The same components as those in the first embodiment shown in FIG. 1 are denoted by the same reference numerals, and the description thereof will not be made in the first embodiment. The explanation which was made is used.

  In the present embodiment, a pair of gap portions 16 are provided along the long side at the upper and lower portions of the optical fiber core wire 13. The width of the gap 16 in the long side direction is formed smaller than the width of the optical fiber cores 13 in each row.

  The optical fiber cores 13 are arranged in two rows in contact with each other along the long side. Therefore, in this case, the uppermost or lowermost optical fiber cores 13 that are in contact with the gap 16 the longest. Is from the contact end with the uppermost or lowermost optical fiber core in the adjacent row to the contact edge of the cable jacket 14. The cross-sectional area of the contact opening formed in this way, that is, the contact area is larger than the projected area of the gap 16. In other words, the projected area of the gap 16 is smaller than the contact area of the contact opening, as in the previous embodiment.

  Even in such a structure, the optical fiber core wire 13 is held in contact with and sandwiched by the cable jacket, and the gap portion 16 is on the long side cross section including the pair of left and right notches 17. It is formed inside the cable jacket 14 so as to come into contact with a part of the core wire 13 through a contact opening, and the contact area of the contact opening to the optical fiber core wire 13 is projected from the optical fiber core wire 13. A configuration is provided that is smaller than the cross-sectional area and prevents the optical fiber core wire 13 from dropping into the gap 16 at the contact edge of the cable jacket 14.

  DESCRIPTION OF SYMBOLS 1 ... Branch part, 2 ... Cable part, 13 ... Optical fiber core wire, 14 ... Cable jacket (sheath), 15 ... Strength body, 16 ... Gap part, 17 ... Notch (notch groove), 21 ... Long side, 22 ... short side, 23 ... contact port, 100 ... optical fiber cable.

Claims (2)

It has a cable part in which optical fiber cores arranged in parallel in two rows are accommodated in a substantially rectangular cable jacket having a long side and a short side, and one or more are respectively provided on both sides of the long side of the cable part. In an optical fiber cable with a notch,
The optical fiber core wire , the long side surface is in contact with the cable jacket, is sandwiched and held,
When the gap portion is horizontally sectioned on the long side, the long side side cross section including the notch inside the cable jacket and on each short side outside the position where the optical fiber core wire is disposed. position and are formed two at a time and each parallel to the top has a contact hole that the void portion is open in a part surface of the short side of the optical fiber, the contact hole is, the one The contact cross-sectional area from the contact end to the optical fiber core wire to the cable jacket is formed smaller than the projected cross-sectional area toward the contact port of the outer shape of the optical fiber core wire, An optical fiber cable characterized in that a drop into a gap is prevented by the cable jacket , and a cut line reaches the gap when a cutting blade is cut into the notch .   2. The notch according to claim 1, wherein the notches are formed on both sides of the long side surface at symmetrical positions around the center line along the long side, and the gap is formed between both notches. Fiber optic cable.

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