JP2012220506A - Optical fiber cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical fiber cable capable of reducing an outer diameter and improving workability in an intermediate branching work.SOLUTION: An optical fiber cable 1 is constituted by disposing two tension members 3 on both sides of multiple coated optical fibers 2, and then coating them entirely with a cable sheath 4. The optical fiber cable 1 includes: two inclusion tapes 6 disposed in the longitudinal direction thereof with the multiple coated optical fibers 2 held therebetween; and at least one tearing string 5 disposed in the vicinity of the inclusion tapes 6. In the cable sheath 4, a mark (projection 7) is formed for indicating a position of the tearing string 5.

Description

  The present invention relates to an optical fiber cable that covers a plurality of optical fiber core wires with a cable jacket.

  With the rapid spread of the Internet, etc., in addition to increasing the speed of information communication and increasing the amount of information, the construction of an optical network for two-way communication and large-capacity communication has recently progressed. FTTH (Fiber To The Home) service that provides high-speed communication services has been started. The demand for wiring work distributed to a plurality of homes and a plurality of terminals is increasing due to the expansion of optical fiber drawing into a subscriber's house and the expansion of a private network.

  Optical fiber cables for FTTH use require an operation (intermediate branching operation) for branching the optical fiber core from the middle of the optical fiber cable in order to connect to an optical cable (such as a drop cable) for drawing into the subscriber's home. Is done. As an example of the structure of such an optical fiber cable, an SZ slot type optical fiber cable as shown in FIG. 2 and an optical fiber cable as shown in FIGS. 3 and 4 are known.

  FIG. 2 is a diagram showing a conventional SZ slot type optical fiber cable. In the figure, 100 indicates an SZ slot type optical fiber cable. This SZ slot type optical fiber cable 100 is made of a resin rod having a plurality of grooves formed in a SZ shape on the outer surface side, with a tension member 102 made of steel wire, steel stranded wire or the like embedded in the center. It is formed using the SZ slot 103.

  A plurality of optical fiber ribbons 101 are accommodated in the groove of the SZ slot 103, and the coarse winding string 104 and the upper winding tape 105 are wound around the outer periphery of the SZ slot 103 to cover the optical fiber ribbon 101. And the thing of the shape which coat | covered the outer side of the upper winding tape 105 with the cable jacket 106 formed by extrusion molding is common.

  FIG. 3 is a view showing a conventional optical fiber cable for wiring disclosed in Patent Document 1. In FIG. In the figure, 110 is an optical fiber cable, 111 is a cable jacket, 112 is a tension member, 113 is an optical fiber core wire, 114 is an inclusion, 115 is a notch, 116 is a support wire, 117 is a support wire coating, and 118 is a support wire coating. Indicates the neck.

  The optical fiber cable 110 is a self-supporting type optical fiber cable, and a plurality of optical fiber core wires 113 are arranged side by side without being twisted at a substantially central portion of the cable jacket 111 and sandwich the optical fiber core wire 113. Thus, the inclusion 114 which is a plastic flat plate is disposed. A tension member (also referred to as a tensile body) 112 is integrally embedded on both sides of the optical fiber core 113, and a V-shaped cut notch 115 for taking out the optical fiber core 113 is formed.

  In addition, the optical fiber cable 110 includes a support wire 116, and the support wire 116 is made of, for example, a 1.2 mmφ steel wire, and the support wire covering 117 that covers the support wire 116 is low through the neck portion 118. It is integrally formed with a cable jacket 111 such as density polyethylene. The optical fiber cable 110 is used as an indoor or drop optical fiber cable regardless of the presence or absence of the support line portion.

  A dedicated dividing tool (not shown) has a blade formed on a base member having a concave cross section, and the base member blade is disposed so as to fit the notch 115 when the optical fiber cable 110 is set and sandwiched between the base members. . Conventionally, the optical fiber core wire 113 is taken out from the intermediate portion of the installed optical fiber cable 110 using a dedicated dividing tool. Specifically, by inserting a blade of a dedicated dividing tool into the notch 115 of the optical fiber cable 110, the cable jacket 111 is divided, and the optical fiber core wire 113 can be taken out.

  FIG. 4 is a diagram showing an optical fiber cable having a structure similar to the optical fiber cable 110 of FIG. In the figure, 120 is an optical fiber cable, 121 is a cable jacket, 122 is a tension member, 123 is an optical fiber core, and 124 is a notch. Unlike the optical fiber cable 110 shown in FIG. 3, the optical fiber cable 120 shown in FIG. 4 has no support line portion and inclusions, and the tear notches 124 are formed on both ends of the tension member 122. Similarly to the case of the optical fiber cable 110 in FIG. 3, the optical fiber cable 120 also uses the dedicated dividing tool to divide the cable jacket 121 from the tear notch 124 and take out the optical fiber core wire 123. .

JP 2008-70601 A

  The SZ slot type optical fiber cable shown in FIG. 2 is excellent in workability at the time of intermediate branching operation and can be applied to optical fiber cores having a wide number of cores from a small number of cores to many cores. There is a problem that the manufacturing cost is increased because the size is relatively large and the number of parts is large.

  On the other hand, the optical fiber cable shown in FIG. 3 or FIG. 4 has a relatively small outer diameter and a small number of parts, so that the manufacturing cost can be reduced compared to the above SZ slot type optical fiber cable. In order to take out the optical fiber core from the cable jacket at the time of intermediate branching work, a special dividing tool designed in accordance with the position of the notch is required. Since this dedicated dividing tool is designed in accordance with the specification of the optical fiber cable, there is a problem that it is not versatile and work using the dedicated dividing tool is troublesome.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an optical fiber cable that can improve the workability of an intermediate branching operation without using a dedicated dividing tool.

  An optical fiber cable according to the present invention is an optical fiber cable in which two tension members are arranged on both sides of a plurality of optical fiber cores and are collectively covered with a cable jacket. Two intervening tapes disposed in the longitudinal direction with the intervening tape interposed therebetween and at least one tear string disposed in the vicinity of the intervening tape, and a mark indicating the position of the tear string is formed on the cable jacket. .

  Moreover, it is preferable that a protrusion is formed on the cable jacket as a mark in the longitudinal direction of the cable jacket. Further, it is preferable that a notch is formed at the base of the protrusion. Moreover, it is preferable that the tear string is in contact with the intervening tape.

  According to the present invention, a plurality of optical fiber core wires are sandwiched between intervening tapes, a tear string is disposed in the vicinity of the intervening tape, and a mark indicating the position of the tear string is formed on the cable jacket. The outer diameter can be reduced compared to the above, and a dedicated dividing tool is not required, and the workability of the intermediate branching work can be improved.

It is a figure which shows an example of the optical fiber cable by this invention. It is a figure which shows the conventional SZ slot type | mold optical fiber cable. It is a figure shown about the conventional optical fiber cable for wiring currently disclosed by patent document 1. FIG. It is a figure which shows the conventional optical fiber cable.

  FIG. 1 is a diagram showing an example of an optical fiber cable according to the present invention. FIG. 1A shows an example of an optical fiber cable having no tear notch, and FIG. 1B shows an example of an optical fiber cable having a tear notch. In the figure, 1 and 1 'are optical fiber cables, 2 is an optical fiber cable, 3 is a tension member, 4 is a cable jacket, 5 is a tear string, 6 is an intervening tape (also called a protective tape), and 7 is a mark. A protrusion 8 is a tear notch.

  In the following description, the optical fiber cable 1 will be described with respect to a configuration that does not include a support line portion. However, as shown in FIG. 3 described above, it is needless to say that a self-supporting configuration including a support line portion may be used. .

  The cable jacket 4 is formed of a thermoplastic resin such as an olefin resin (for example, polyethylene) and accommodates a plurality of optical fiber core wires 2 without being twisted. The optical fiber 2 is called an optical fiber in which a glass fiber having a standard outer diameter of 125 μm is coated with a coating outer diameter of about 250 μm, and further, a coating or a colored coating is provided on the outer side. A plurality of optical fiber cores may be arranged in a line, and the number of accommodation is arbitrary. Moreover, the optical fiber core wire 2 may be a tape core wire in which a plurality of optical fiber core wires are integrated in a parallel line, or may be a form in which a plurality of tape core wires are used in an overlapping manner.

  The tension member 3 is also called a strength member, and a wire rod having a resistance to tension and compression is used. As this wire, for example, a steel wire having an outer diameter of about 0.40 to 0.70 mm, FRP (Fiber Reinforced Plastics), or the like is used. The outer diameter of the tension member 3 is appropriately determined according to the thickness when a plurality of optical fiber cores 2 are arranged. The intervening tape 6 is a tape-like member made of plastic such as polyethylene or polyester (PET) having a thickness of about 0.05 to 0.10 mm. It is also possible to protect the fiber core wire 2 from piercing the spawning tube.

  As the tear string 5, it is preferable to use a material having a high tensile strength in order to tear the cable jacket 4, remove the intervening tape 6, and take out the optical fiber core wire 2 therein. For example, an aramid fiber such as Kevlar having an outer diameter of about 0.70 mm can be used.

  In FIG. 1A, an optical fiber cable 1 includes two intervening tapes 6 arranged in the longitudinal direction with a plurality of optical fiber cores 2 interposed therebetween, and at least one intervening tape 6 arranged in the vicinity of the intervening tape 6. A tear string 5 is provided. A mark indicating the position of the tear string 5 is formed on the cable jacket 4. If one tear string 5 is provided, the cable jacket 4 can be torn and the inner optical fiber core wire 2 can be taken out. In this example, the two tear strings 5 are connected to the approximate center of the cable. As a mark, two protrusions 7 are formed in the longitudinal direction of the cable jacket 4. At this time, it is desirable that the two tear strings 5 are in contact with the intervening tape 6, respectively, whereby the optical fiber core wire 2 can be more easily taken out.

  With respect to the optical fiber cable 1, the operator cuts the peripheral portion of the protrusion 7 formed on the cable jacket 4 using a general tool such as a peeler or a cutter, and removes the tear string 5. Take out. And by tearing the cable jacket 4 using the taken-out tear string 5, the intervening tape 6 can be removed and the optical fiber core wire 2 inside thereof can be easily taken out. At this time, since the optical fiber core wire 2 is protected by the intervening tape 6, it is not damaged by the above-mentioned tool during operation.

  As described above, the plurality of optical fiber core wires 2 are sandwiched between the intervening tapes 6, the tear string 5 is disposed in the vicinity of the intervening tape 6, and the protrusion 7 indicating the position of the tear string 5 is formed on the cable jacket 4. The outer diameter can be made smaller than that of the slot type optical fiber cable, and it is not necessary to use a dedicated dividing tool, so that the workability of the intermediate branching work can be improved. In addition, since the operator can easily know the position of the tear string 5 by the protrusions 7, it becomes easy to perform work even during night work.

  The optical fiber cable 1 described above may be arranged such that when a plurality of optical fiber cores are arranged, adjacent optical fiber cores are adjacent to each other and are also in contact with the intervening tape 6. desirable. When a plurality of tape cores are arranged, it is desirable that the tape cores and the tape core and the intervening tape 6 are in contact with each other. Thereby, when the cable jacket 4 is formed, the resin material of the cable jacket 4 does not enter between the optical fiber cores 2 and between the optical fiber core 2 and the interposition tape 6. 2 and the cable jacket 4 are not in close contact with each other, and the take-out property of the optical fiber core wire 2 can be improved.

  In the case of this example, the width of the intervening tape 6 is substantially the same as the arrangement width when the optical fiber cores 2 are gathered and arranged, but the optical fiber core 2 is composed of a tape core. In this case, it is not necessary to cover the entire arrangement width of the tape cores with the intervening tape 6. If the intervening tape 6 covers about half of the tape cores at both ends in the width direction, the optical fiber core 2 Can be taken out.

  In addition, the mark formed on the cable jacket 4 is not limited to the protrusion 7, and instead of the protrusion 7, a color may be added to the position of the tear string 5 so that the position of the tear string 5 can be known. Any form is acceptable.

  In FIG. 1A, as an example of the configuration of the optical fiber cable 1, a = 3.1 mm, b = 0.4 mm, c = 2.3 mm, d = 0.7 mm, e = 6.1 mm, and f = 0. 4 mm, g = 0.2 mm, and h = 0.2 mm. In addition, if the height b of the protrusion 7 is too large, there is a problem in laying, and if it is too small, it is difficult to discriminate. For example, it is 0.1 mm or more and 2.0 mm or less. Also, if the distance f from the surface of the cable jacket 4 to the tear string 5 is too large, it is difficult to remove the tear string 5, and if it is too small, the tear string 5 may be exposed. It is desirable to form in such a range. For example, it is 0.1 mm or more and 2.0 mm or less.

  The thus configured optical fiber cable 1 can take out the tear string 5 by scraping the cable jacket 4 around the protrusion 7 using a common tool such as a peeler or a cutter in the middle portion of the cable. it can. Then, by tearing the cable jacket 4 with the tear string 5 to expose the intervening tape 6 and further removing the intervening tape 6, the internal optical fiber core wire 2 can be taken out.

  Further, as shown in FIG. 1B, at least one slit notch 8 may be formed in the root portion of the protrusion 7. In this example, a total of four slit notches 8 are formed in the two protrusions 7. Thereby, even if an operator does not use a peeler, he can tear off the tear notch 8 with a nipper or the like and take out the tear string 5 more easily.

  As described above, according to the present invention, a plurality of optical fiber cores are sandwiched between intervening tapes, a tear string is disposed in the vicinity of the intervening tape, and a mark indicating the position of the tear string is formed on the cable jacket. The outer diameter can be made smaller than that of the optical fiber cable, and a dedicated dividing tool is not required, and the workability of the intermediate branching operation can be improved.

DESCRIPTION OF SYMBOLS 1,100,110,120 ... Optical fiber cable, 2, 101, 113, 123 ... Optical fiber core wire, 3, 102, 112, 122 ... Tension member, 4, 106, 111, 121 ... Cable jacket, 5 ... Tear string, 6 ... intervening tape, 7 ... protrusion, 8, 115,124 ... tear notch, 103 ... SZ slot, 104 ... coarse winding string, 105 ... overwinding tape, 114 ... inclusion, 116 ... support line, 117 ... Support wire coating, 118 ... neck.

Claims (4)

An optical fiber cable in which two tension members are arranged on both sides of a plurality of optical fiber cores and are collectively covered with a cable jacket,
Two interposed tapes arranged in the longitudinal direction across the plurality of optical fiber core wires, and at least one tear string arranged in the vicinity of the interposed tape, the cable jacket includes An optical fiber cable having a mark indicating a position of a tear string.   The optical fiber cable according to claim 1, wherein a protrusion is formed in the cable jacket as the mark in the longitudinal direction of the cable jacket.   The optical fiber cable according to claim 2, wherein a notch is formed in a base portion of the protrusion.   The optical fiber cable according to claim 1, wherein the tear string is in contact with the interposition tape.

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