JP2006071897A - Optical fiber cable - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical fiber cable in which a cable sheath is easily ripped to take out internal coated optical fibers using a readily available electric wire tool such as a normally called nipper regardless of the outer shape or the difference in the size of the cable. <P>SOLUTION: In an optical fiber cable, one or a plurality of coated optical fibers 11 is arranged at the cable center section, tension members 12a and 12b are arranged on both sides of the fibers 11 and a cable sheath 13 integrally coats the all of the above. A pair of wedge shaped notches 15 is arranged without spanning the fibers 11. A minimum distance L between tips 15a of the wedge shaped notches 15 and a sheath inner wall surface 13a, which stores the coated optical fibers 11, is set smaller than a distance M which is the distance between the tips 15a of an pair of wedge shaped notches 15. Moreover, the pair of wedge shaped notches 15 is arranged to sandwich the tension member 12a. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an optical fiber cable that is used as a drop optical fiber cable or an indoor optical fiber cable in which tension members are disposed on both sides of an optical fiber core disposed in the center of the cable and are integrally covered with a 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. For this reason, the demand of the drop optical fiber cable used for drawing in to a house and the indoor optical fiber cable for indoor wiring is increasing.

  For example, as shown in FIG. 6A, these optical fiber cables generally have tension members 2 arranged in parallel on both sides of the optical fiber core wire 1 and are covered with a cable jacket 3 so as to be integrally covered. A structure with increased tensile strength is used. Further, this optical fiber cable is integrally provided with a support wire portion 4, and the support wire portion 4 is removed by tearing by hand so that it can also be used as an indoor optical fiber cable. And the V-shaped notch 5 for tearing the cable jacket 3 and taking out the internal optical fiber core wire 1 is provided in the both sides | surfaces of the cable jacket 3 normally.

  When the optical fiber core wire 1 is taken out from the middle portion of the cable, first, a notch 5 is cut to start tearing, and then the notch 5 is torn by hand. When making this cut, a special tool 6 called a detacher as shown in FIG. 6 (B) is used to take out the optical fiber core wire in the cable without cutting or scratching it. There is a method to use (for example, refer to Patent Document 1). The tool 6 includes, for example, lower gripping portions 7a and 7b and upper gripping portions 8a and 8b, and has an engaging protrusion 9 at the tip of these gripping portions.

The upper gripping portions 8a and 8b are openable and closable with respect to the lower gripping portions 7a and 7b, for example, and store an intermediate portion of the optical fiber cable in a tool storage portion 6a so that it can be taken out. The engaging protrusions 9 at the tips of the lower gripping portions 7a and 7b are engaged with one notch 5 side of the cable, and the upper gripping portions 8a and 8b are closed and the engaging protrusion 9 is connected to the other notch 5 side of the cable. Engage with. Next, the left upper and lower gripping portions 7a and 8a are moved to the left and the right upper and lower gripping portions 7b and 8b are moved to the right to cut the notch 5 part to the left and right. An optical fiber core having a desired length is taken out by continuously tearing from the portion.
JP 2000-121839 A

  By using a special tool as described above, it is possible to tear the cable and take out the optical fiber core wire without damaging the optical fiber cable. However, when the outer shape and dimensions of the optical fiber cable are different, one type of tool cannot be used, and it is necessary to prepare a plurality of tools suitable for each optical fiber cable. For this reason, the work contractor should purchase all of these tools and bring all the tools to the work place, or check the type of construction cable and do not forget the predetermined tool. There was annoyance that I had to go out.

  The present invention has been made in view of the above-described circumstances, and generally uses a general wire tool such as a nipper, and can easily be connected to a cable regardless of differences in cable outer shape and dimensions. An object of the present invention is to provide an optical fiber cable capable of tearing the jacket and taking out the inner optical fiber core wire.

  An optical fiber cable according to the present invention is an optical fiber cable in which one or more optical fiber cores are arranged at the center of the cable, tension members are arranged on both sides thereof, and are integrally covered with a cable jacket. A pair of wedge-shaped notches are provided so as not to straddle the core wires, and the shortest distance L between the tips of the wedge-shaped notches and the inner wall surface of the jacket for storing the optical fiber core wires is smaller than the distance M between the tips of the pair of wedge-shaped notches. To be. The pair of wedge-shaped notches are provided so as to sandwich the tension member. In order to store the optical fiber core in the cable, the optical fiber core may be vertically inserted with an intervening fiber material, or may be stored via a gap.

  According to the present invention, the wedge-shaped notch provided without straddling the optical fiber core in the cable is cut with a commercially available nipper such as used for cutting an electric wire, and a part of the jacket is placed on the side of the cable. The optical fiber core wire can be easily taken out simply by tearing it. In addition, regardless of the outer shape and size of the optical fiber cable, the cable can be torn using the same nipper, and the cost efficiency and workability can be improved.

  The outline of the present invention will be described with reference to FIG. FIG. 1A is a diagram for explaining an outline of an optical fiber cable according to the present invention, and FIGS. 1B and 1C are diagrams for explaining a tearing state of a cable jacket. In the figure, 11 is an optical fiber core (tape core), 12a and 12b are tension members, 13 is a cable jacket, 13a is an inner wall surface of the jacket, 13b is an ear, 14 is a support wire, and 15 is a wedge-shaped notch. , 15a indicates a notch tip.

  As shown in FIG. 1 (A), for example, the optical fiber cable according to the present invention has two or more optical fiber core wires 11 in the center portion of the cable, for example, two superposed optical fiber cores. The tension members 12a and 12b are arranged on both sides (upper and lower sides in the figure) and are integrally covered with a cable jacket 13. In the cable jacket 13, for example, a pair of wedge-shaped notches 15 are formed with the outer tension member 12a interposed therebetween. A pair of wedge-shaped notches 15 is inserted with a general nipper as an electric wire tool so as to make a cut, and then the sandwiched portion is torn to expose the inner optical fiber core wire 11. Can be taken out.

  The optical fiber core 11 in the present invention is a so-called 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 a reinforcing coating on the outside thereof. It shall include all of the structures etc. that have been subjected to. In addition, in FIG. 1, an example using a tape core obtained by tape-forming a plurality of optical fiber cores will be described, but in addition to this, one to several single optical fiber core wires are connected by a cable jacket 13. The present invention can be similarly applied to the form of direct coating.

  In the description of the present invention, a self-supporting example in which the support wire portion 14 is integrally provided on the main body portion of the optical fiber cable is used. However, the present invention can be similarly applied to use in a form in which the support line portion 14 is removed, or to an optical fiber cable that does not have the support line portion 14 from the beginning. As the tension member 12, for example, a steel wire having an outer diameter of about 0.4 mm, glass fiber reinforced plastic (FRP), aramid fiber reinforced plastic (K-FRP), or the like is used. A steel wire of about 2 mm is used. Further, the cable jacket 13 constituting the main body of the optical fiber cable is often rectangular in cross section, but is not particularly limited to this, and will be described later with reference to FIGS. 5 (A) to 5 (C). An elliptical shape or a circular shape as shown can also be used.

  In the optical fiber cable according to the present invention, as shown in FIG. 1B, the pair of wedge-shaped notches 15, for example, sandwich the outer tension member 12 a from both sides and gradually increase the distance toward the optical fiber core wire 11. It is formed so as to be narrowed into a “C” shape. And the line which connects between the notch tips 15a of the wedge-shaped notches 15 is formed so as not to straddle the optical fiber core wire 11 disposed in the center of the cable.

  In the present invention, L is the shortest distance between the notch tip 15a of the wedge-shaped notch 15 and the inner wall surface 13a of the outer sheath of the optical fiber core wire 11, and M is the distance between the notch tips 15a of the pair of wedge-shaped notches 15. When L <M. In the example of FIG. 1 (B), the notch tip 15a is formed so as to be positioned approximately in the middle between the optical fiber core wire 11 and the tension member 12a. The outer wall surface 13a of the jacket is a contact interface when the optical fiber core wire 11 is in direct contact with the cable jacket 13 by covering, and is also the outer peripheral surface of the optical fiber core wire 11.

  Assume that in the optical fiber cable having the above-described configuration, it becomes necessary to take out the optical fiber core wire 11 from the middle portion of the cable by branching the optical fiber or the like. In this case, the nipper blade portion is inserted into the pair of wedge-shaped notches 15 so as to be eaten, and the sandwiched portion is pulled out to the side perpendicular to the cable longitudinal direction. As shown in FIG. 1 (C), the cable sheath that surrounds the tension member 12a surrounds the tension member 12a due to a crack that reaches the outer wall surface 13a of the optical fiber core wire 11 from the notch tip 15a. The part is torn off. Subsequently, the optical fiber core wire 11 having a desired length range can be exposed by tearing the torn portion as a starting point. In addition, by gripping the torn portion 13b of the cable jacket 13 by hand and opening it to the left and right, the center portion can be opened wide and the internal optical fiber core wire 11 can be easily taken out.

  FIG. 2 shows another example of forming the wedge-shaped notch 15. 2A shows an example in which a wedge-shaped notch is formed on the support line side, and FIG. 2B shows an example in which the wedge-shaped notch is formed on the side surface side of the cable jacket 13. The reference numerals in the figure are the same as those used in FIG. 2A and 2B, the shortest distance L between the notch tip 15a of the wedge-shaped notch 15 and the inner wall surface 13a in which the optical fiber core wire 11 is accommodated is a pair of wedge shapes. The notch 15 is formed to be smaller than the distance M between the notch tips 15a.

FIG. 2A shows a pair of wedge-shaped notches 15 sandwiched from both sides of a tension member 12b positioned on the support wire portion 14 side, and gradually becomes narrower toward the direction of the optical fiber core wire 11 to form a “C” shape. This is an example of providing. In this case as well, as in the example shown in FIG. 1, the wedge-shaped notch 15 is nipped so that the nippers are bitten regardless of whether or not the support line portion 14 is present, and the sandwiched portion is laterally orthogonal to the longitudinal direction. The optical fiber core wire 11 having a desired length range can be exposed.
By providing the wedge-shaped notch 15 so as to sandwich the tension member 12a or 12b, the tension member is pulled out when the cable jacket is torn. Therefore, the pull-out portion is not cut off in the middle, and it is reliably and easily torn. Can be performed.

  In FIG. 2B, the pair of wedge-shaped notches 15 are formed in a “C” shape with the interval gradually narrowing toward the side of the optical fiber core 11 on the side surface side of the cable jacket 13 without the tension member. It is an example provided in. Also in this case, the nippers are nipped into the wedge-shaped notch 15 and the nipped portion is pulled out to the side perpendicular to the longitudinal direction for tearing. Can be exposed.

  FIG. 3 is a diagram showing various embodiments in consideration of taking out the optical fiber core wire. In the figure, 16 is an interposition, 17 is a gap, 18 is a cavity, and the other symbols are the same as those used in FIG. 3A to 3D, the shortest distance L between the notch tip 15a of the wedge-shaped notch 15 and the inner wall surface 13a in which the optical fiber core wire 11 is accommodated is a pair. The wedge-shaped notch 15 is formed to be smaller than the distance M between the notch tips 15a.

  FIG. 3A shows an example in which two optical fiber cores are used as the optical fiber core wire 11 and the interposition 16 is vertically attached between the two optical tape core wires. By arranging a non-woven fabric between the two tape core wires, as shown in FIG. 1 (C), when the cable jacket surrounding the tension member 12a sandwiched between the wedge-shaped notches 15 is torn off, By pulling out 16, the tape cores on both sides can be easily taken out. The intervening 16 can be a non-woven tape that is generally known as a water-absorbing tape for an optical fiber cable. In addition, a high-strength fiber such as Kevlar (registered trademark), a woven fabric tape, or the like can also be used. . In FIG. 3A, an example in which the interposition 16 is vertically provided between two tape cores is shown, but it may be arranged between the outside of the tape core and the cable jacket 13, One tape core may be used.

  FIG. 3B shows an example in which a single tape core is used as the optical fiber core 11 and is stored between the tape core and the cable jacket 13 via a gap 17. In addition, the surface of the tape core wire storage part forming the gap 17 becomes the above-described inner wall surface 13a of the jacket. By storing the tape core wire so as to have a gap around the outer periphery of the tape core wire, the tape core wire and the cable jacket 13 are free from adhesiveness. As a result, when the cable jacket surrounding the tension member 12a sandwiched between the wedge-shaped notches 15 is torn off, the tape core wire can be easily taken out.

  FIG. 3C shows an example in which a plurality of single-core optical fiber core wires 11 are accommodated in a hollow portion 18 formed in the center portion of the cable jacket 13 so that a space portion is filled with interpositions 16. 3D shows that the single-core optical fiber core 11 is housed loosely in the hollow portion 18 formed in the center portion of the cable jacket 13 via the gap 17, and the support wire portion. An example without 14 is shown. In the example shown in FIGS. 3C and 3D, the surface of the cavity 18 is the inner wall surface 13a of the jacket. By housing a plurality of single-core optical fiber cores 11 in the cable jacket 13 via the intervening 16 or the gap 17, the cable jacket portion surrounding the tension member 12 a sandwiched between the wedge-shaped notches 15 was torn off. At this time, it is possible to easily take out the single-core optical fiber.

  FIG. 4 is a diagram showing an example in which a plurality of single-core optical fiber cores are directly embedded in a cable jacket. FIG. 4 (A) shows an example of two cores, and FIG. FIG. 4C is a diagram showing an example in which the above-described intervention is added vertically. The reference numerals in the figure are the same as those used in FIGS. 4A to 4C, the shortest distance L between the notch tip 15a of the wedge-shaped notch 15 and the inner wall surface 13a in which the optical fiber core wire 11 is accommodated is a pair of wedge shapes. The notch 15 is formed to be smaller than the distance M between the notch tips 15a. Since the optical fiber core wire 11 is in direct contact with the cable jacket 13, the contact interface between the cable jacket 13 and the optical fiber core wire 11 becomes the jacket inner wall surface 13 a.

  FIGS. 4A and 4B show a cable in which a plurality of single-core optical fiber cores 11 are directly embedded in the cable jacket 13, and a pair of wedge-shaped notches 15 are arranged in the direction of the optical fiber core 11. This is an example in which the interval is gradually narrowed toward the direction of “” and is formed in a “C” shape. Also in this case, the nippers are nipped into the wedge-shaped notch 15 and the nipped portion is pulled out to the side perpendicular to the longitudinal direction for tearing. Can be exposed. However, depending on the arrangement state of the optical fiber cores 11, it is difficult to take out the optical fiber cores arranged at a deeper position. Therefore, it is applicable to the case where the number of optical fiber cores is relatively small, that is, 8 cores or less. desirable.

  The example of FIG. 4C is an example in which the interposition 16 described in FIG. 3A is vertically attached to the optical fiber core wire 11 embedded directly in the cable jacket 13. When the optical fiber core wire 11 is directly embedded in the cable jacket 13 and the takeout property of the optical fiber core wire 11 is deteriorated, it can be improved by adding the interposition 16 vertically. In this case, for example, the interposition 16 only needs to lay a tape-shaped non-woven fabric parallel to the optical fiber core wire 11, so that the cable jacket 13 is not directly in contact with the outer surface of the optical fiber core wire 11. A part is formed and the take-out property of the optical fiber core wire 11 can be improved.

  As shown in FIGS. 3C and 3D, when an optical fiber core wire is housed in a cable jacket so as to be movable through an intervening gap, the optical fiber moves in the cable due to vibration or the like. This phenomenon may cause the optical fiber to protrude from the cable connection. If the optical fiber protrudes, the optical fiber is sharply bent to increase the transmission loss or break the optical fiber. However, as shown in FIGS. 4 (A) and 4 (B), in the case of an optical fiber cable with a small number of cores, the optical fiber core wire 11 is directly embedded in the cable jacket 13 as described above. The problem can be solved. Further, as shown in FIG. 4C, by combining with the use of the interposition 16, the takeout property of the optical fiber core wire 11 can be improved.

  5A and 5B are diagrams showing examples of other optical fiber cables. FIG. 5A shows an example in which the cable jacket cross section is an ellipse, FIG. 5B shows an example in which the cable jacket cross section is a circle, and FIG. ) Is a diagram showing an example of an optical fiber cable having a large number of cores. The reference numerals in the figure are the same as those used in FIGS. 5A to 5C, the shortest distance L between the notch tip 15a of the wedge-shaped notch 15 and the inner wall surface 13a in which the optical fiber core wire 11 is accommodated is a pair of wedge shapes. The notch 15 is formed to be smaller than the distance M between the notch tips 15a.

  5 (A) and 5 (B) show an example in which the optical fiber core wire 11 is directly embedded in the cable jacket 13 as in FIGS. 4 (A) and 4 (B). A tape core wire may be used as the core wire 11, and an interposition may be provided vertically. In each example, the pair of wedge-shaped notches 15 are formed so as to sandwich the outer tension member 12a. However, as described in FIG. 2, the pair of wedge-shaped notches 15 sandwich the tension member 12b on the support line portion 14 side. You may form, and you may form in the side surface side of the cable jacket 13 without a tension member. FIG. 5C is an example in which a large number of optical fiber cables 11 are accommodated in a circular cavity 18 via intervening 16 or gaps, using a relatively large diameter optical fiber cable. The cable jacket 13 is formed with a relatively thick coating, tension members 12a and 12b are embedded in at least two places, and a pair of wedge-shaped notches 15 are formed with one tension member 12a interposed therebetween.

  In any of the examples of FIGS. 5A to 5C, the cable jacket cross section shown in FIG. 1 is generally used as a wire tool at a pair of wedge-shaped notches 15 as in the rectangular example. A nipper blade portion is inserted and eaten, and the sandwiched portion is pulled out to the side perpendicular to the longitudinal direction. By this drawing, a crack that reaches the inner wall surface of the outer jacket where the optical fiber core wire 11 comes into contact from the notch tip 15a enters, and the cable jacket portion surrounding the tension member 12a is torn off. Subsequently, the optical fiber core wire 11 having a desired length range can be exposed by tearing the torn portion as a starting point.

  As shown in FIG. 1, when the cross-sectional shape of the cable jacket of the optical fiber cable is rectangular, the wedge-shaped notch 15 is formed by cutting from the corner of the jacket 13 in the direction of the optical fiber core wire. The For this reason, the effective width of the both side surfaces 13a of the jacket 13 can be widened, and the marking characters and the like can be easily given in a size that can be easily identified as shown in FIG. In addition, when this optical fiber cable having a rectangular cross section is used as a drop optical fiber cable, it can be introduced in a sealed state without any additional changes to the introduction part of the existing closure when pulled down from the outdoor closure.

It is a figure explaining the outline of the present invention. It is a figure which shows the other example of formation of the wedge-shaped notch by this invention. In this invention, it is a figure which shows the various formation examples in consideration of taking out of an optical fiber core wire. In this invention, it is a figure which shows the example of a formation which embeds the several single core optical fiber core wire directly in a cable jacket. It is a figure which shows the example of formation of the other optical fiber cable by this invention. It is a figure explaining the prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Optical fiber core wire (tape core wire), 12a, 12b ... Tension member, 13 ... Cable jacket, 13a ... Jacket inner wall surface, 13b ... Ear part, 14 ... Support wire part, 15 ... Wedge-shaped notch, 15a ... Notch tip, 16 ... interposition, 17 ... gap, 18 ... cavity.

Claims (5)

  An optical fiber cable in which one or more optical fiber cores are arranged at the center of the cable and tension members are arranged on both sides thereof and are integrally covered with a cable jacket so as not to straddle the optical fiber cores. A pair of wedge-shaped notches is provided, and the shortest distance L between the front end of the wedge-shaped notch and the inner wall surface of the outer casing in which the optical fiber core wire is accommodated is made smaller than the distance M between the front ends of the pair of wedge-shaped notches. An optical fiber cable.   The optical fiber cable according to claim 1, wherein the pair of wedge-shaped notches are provided so as to sandwich the tension member.   The optical fiber cable according to claim 1 or 2, wherein an intervening made of a fiber material is vertically attached to the optical fiber core wire.   The optical fiber cable according to claim 1 or 2, wherein the optical fiber core wire is accommodated through a gap.   The optical fiber cable according to any one of claims 1 to 4, wherein a cross-sectional shape of the cable jacket is rectangular.

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