JP3928114B2 - 2-core tape type 8 core drop cable with extra length - Google Patents

Description

  The present invention relates to a two-core tape type eight-core drop cable with extra length using an optical fiber as a cable.

  With the progress of communication networks using optical fibers, optical fiber cables are being wired. Examples of the optical fiber drop cable include a single-core wire, a two-core type using a two-core tape, and a four-core type using a four-core tape.

  In conventional fiber optic cables with a suspension line, the suspension line may be stretched when tension due to natural phenomena such as tension at the time of cable laying extension, tension at the time of cable laying, or wind pressure is applied to the suspension line. If the lengths of the cables are the same, the optical fiber cable is also stretched and there is a risk of disconnection.

As described in Patent Document 1, in order to prevent the optical fiber cable from being disconnected, an invention of a method for manufacturing an optical fiber cable with a suspension line in which an extra length is provided in the optical fiber cable and is longer than the suspension line is also disclosed. .
Japanese Patent Laid-Open No. 7-230028

  FIG. 5 is a front view of a conventional optical fiber cable with a suspension line. The optical fiber cable 8 with a suspension line is a single-core optical fiber, and includes a suspension line 9, an optical fiber cable 10, and a connection portion 11.

  The suspension line 9 and the optical fiber cable 10 are covered and molded, and there is also a structure that is connected by a connection portion 11. When the suspension line 9 extends, the optical fiber cable 10 is not cut so that the extra length is provided in the optical fiber cable 10. Some of them have

  The suspension wire 9 is a hard wire that is thinner than the optical fiber cable 10 and serves as a guide when the suspension-attached optical fiber cable 8 is wired so that the optical fiber cable 10 is not bent unnecessarily. Protect.

  FIG. 6 is a cross-sectional view of a conventional optical fiber cable with a suspension line. The suspension line 9 suspends the optical fiber cable 10 by connecting several places on the suspension-attached optical fiber cable 8 with the connection portion 11.

  The suspension wire 9 includes a steel support wire 9a so that the optical fiber cable 10 is not bent excessively. An optical fiber 10a is contained inside the optical fiber cable 10, and the surface is covered with a sheath material or the like.

  However, the 8-fiber drop cable with 4 2-fiber ribbons has no extra length, and there is a risk of disconnection because the optical fiber cable is supported by a single steel wire. The steel wire in the suspension line is also thick.

  In addition, since the conventional optical fiber cable with a hanging wire has no notch or the like, there is a drawback that it is not easy to take out the optical fiber when connecting to a device or the like.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a two-core tape type eight-core drop cable with an extra length in which an extra length is provided in an optical fiber cable so as to prevent disconnection due to extension of the extension line, etc. It is.

In order to solve the above problems, the present invention
Two-core tape cores 5, 5a, 5b, 5c, which are laminated in parallel to the long side of the cable cross section, are arranged on the upper and lower sides, above the upper two-core tape cores 5, 5a. Further, the tension members 7 and 7a are passed under the lower two-core tape cores 5b and 5c, and then the two-core tape cores 5, 5a, 5b and 5c and the tension members 7 and 7a are covered with a sheath material 3g. Covered in a rectangular shape, the upper left notch 3a and the upper right notch 3c hit the lower two-core tape cores 5b and 5c in a triangular shape at a position corresponding to the upper two-core tape cores 5 and 5a on the side surface of the sheath material 3g. An optical fiber cable 3 provided with a lower left notch 3b and a lower right notch 3d in a triangular shape at a position; a suspension line 2 in which a support line 2a for suspending the optical fiber cable 3 is covered with a sheath material 2b;
The optical fiber cable 3 includes a connecting portion 4 that is intermittently connected to the suspension line 2 after securing extra lengths 3e and 3f, and the optical fiber cable 3 is connected so as to draw a gentle curve. It was set as the structure of the 2 core tape type 8 core drop cable with extra length .

  Since this invention is the above structure, the following effects are acquired. First, an extra length is provided in the optical fiber cable so that it is longer than the suspension line, so that tension due to natural phenomena such as tension at the time of cable laying, tension at the time of cable laying, and wind pressure is added to the suspension line, and the suspension line extends. The optical fiber cable will not be broken even if it is

  Secondly, by supporting the tension member in the optical fiber cable from both sides of the two-core tape core instead of one centered on the tension member, the optical fiber cable is reinforced and the optical fiber cable is disconnected. Can be prevented.

  Thirdly, by making the thickness of the steel wire in the suspension line half or less, the whole can be made small, and space saving can be achieved. Further, since the weight is reduced, the pressure of wind or the like can be reduced, and the work at the time of cable laying extension is facilitated.

  Fourthly, by providing four notches, it is possible to easily take out the two-core tape core wire that is divided into two portions by two without damaging the optical fiber.

  The two-core tape core wire, the tension member, and the support wire are collectively covered with a sheath material, but an extra length is attached to the optical fiber cable, and then the optical fiber cable and the suspension wire are connected.

  Below, based on an accompanying drawing, the extra length 2 core tape type 8 core drop cable which is the present invention is explained in detail. FIG. 1 is a front view of a two-core tape type eight-core drop cable with extra length according to the present invention. The extra-length two-core tape type eight-core drop cable 1 includes a suspension line 2, an optical fiber cable 3, and a connection portion 4.

  The suspension line 2 is a line that supports the optical fiber cable 3 by suspending it, and a support line 2a made of steel is contained inside. The optical fiber cable 3 is a line for propagating light, and contains therein two-core tape core wires 5, 5a, 5b, 5c and tension members 7, 7a each having two optical fibers. The suspension line 2 and the optical fiber cable 3 are intermittently connected and suspended by the connection portion 4.

  The tension members 7 and 7a have a structure in which a tensile tension is not directly applied to the optical fiber itself at the center of the optical fiber cable 3. Sometimes soft materials such as aramid fibers are used. In the two-core tape type eight-core drop cable 1 with extra length, two steel wires having a diameter of about 0.4 mm to 0.8 mm are put.

  The extra-length two-core tape type eight-core drop cable 1 covers the two-core tape core wires 5, 5a, 5b, 5c, the tension members 7, 7a, and the support wires 2a all together with a sheath material 3g. After adding extra lengths 3e and 3f, the optical fiber cable 3 and the suspension line 2 are connected.

  The sheath material 3g is for protecting the optical fiber, and there are various types such as polyethylene, nylon, Teflon (registered trademark), polyvinyl chloride (PVC), PVC monocoil, stainless steel (SUS), and flexible pipe. In the two-core tape type eight-core drop cable 1 with extra length, non-halogen flame-retardant polyethylene is used.

  On the surface of the optical fiber cable 3, an upper left notch 3a, a lower left notch 3b, an upper right notch 3c, and a lower right notch 3d are provided on the front side and the back side, respectively. The upper left notch 3a, the lower left notch 3b, the upper right notch 3c, and the lower right notch 3d are grooves cut into a triangular shape so that the sheath material 3g can be cut out and the optical fiber can be easily taken out when connecting to a device or the like.

  FIG. 2 is a plan view of an extra length two-fiber tape type eight-core drop cable according to the present invention. Between one connection portion 4 and another connection portion 4, the optical fiber cable 3 has extra lengths 3 e and 3 f, and therefore is longer than the suspension line 2.

  The extra lengths 3e and 3f are portions longer than the suspension line 2 of the optical fiber cable 3. The suspension line 2 and the optical fiber cable 3 are connected by the connecting portion 4 after extra lengths 3e and 3f are put in the optical fiber cable 3.

  Even when the tension due to a natural phenomenon such as tension at the time of laying a cable, tension at the time of cable laying, wind pressure, etc. is applied to the suspension line 2 and the suspension line 2 is extended, the optical fiber cable 3 has a margin for the extra lengths 3e and 3f. Therefore, there is little risk that the optical fiber cable 3 is stretched and disconnected.

  In the interval between one connection portion 4 and another connection portion 4, the length of the suspension line 2 is about 250 mm, the length of the optical fiber cable 3 is about 251 mm, and the optical fiber cable 3 is about 0 with respect to the suspension line 2. .4% extra length 3e, 3f. The range of the extra lengths 3e and 3f is preferably 0.1% to 0.4%, and is 2% at the maximum, and varies depending on the environment such as the installation location.

  Since the optical fiber cable 3 is a little longer with the extra lengths 3e and 3f, the optical fiber cable 3 will draw a curve even if the suspension line 2 is straightened. And the optical loss does not increase.

  The extra lengths 3e and 3f are not limited to the two-core tape type eight-core drop cable 1 with extra length, but can be used for a single-core cord, two-core type, four-core type or other drop cables. Disconnection due to expansion can be prevented.

  FIG. 3 is a cross-sectional view of a two-core tape type eight-core drop cable with extra length according to the present invention. The support wire 2a is contained inside the circular suspension wire 2, and the inside of the optical fiber cable 3 contains four 2-core tape core wires 5, 5a, 5b, 5c, and two tension members 7, 7a. ing.

  The cross section of the extra-length two-core tape type eight-core drop cable 1 has a size of about 10.0 mm in the vertical direction and a size of about 4.0 mm in the horizontal position, and the mass per km is about 100 kg or less.

  The support wire 2a supports the optical fiber cable 3 with a steel wire having a diameter of 1.2 mm to 3.0 mm, preferably 1.2 mm to 2.6 mm. Even if there is an external pressure such as bending of the extra length 2-core tape type 8-core drop cable 1, the optical fiber cable 3 is protected from being directly applied.

  The optical fibers 6, 6 a, 6 b, 6 c, 6 d, 6 e, 6 f and 6 g are fiber-like ones made of a transparent material such as glass, and are located at the center of the optical fiber cable 3 and propagate light. In the two-core tape type eight-core drop cable 1 with a surplus length, the type is an SM type quartz fiber. Since the optical fibers 6 to 6 g themselves are considerably weak, they are double-coated with an ultraviolet curable resin. The outer diameter of the primary coating is 250 μm, and the outer diameter of the secondary coating is about 0.4 mm in thickness and about 0.6 mm in width.

  Two-core tape cores 5, 5a, 5b, and 5c are optical fibers 6 to 6g having two cores, and there are combinations of blue and white, yellow and white, green and white, and red and white. . The color may be changed and the arrangement is not limited. In the extra-length two-core tape type eight-core drop cable 1, the two-core tape cores 5 and 5a and the two-core tape cores 5b and 5c are separately provided.

  Each of the optical fibers 6 to 6g of the two-core tape core wires 5, 5a, 5b, and 5c of the two-core tape type eight-core drop cable 1 with extra length has a mode field diameter of 9.2 μm and a cladding diameter of 125 μm. Yes. The mode field diameter may be further reduced.

  The mode field diameter represents the spread of light confined in the optical fiber, and the cladding diameter is composed of a material having a lower refractive index than the central portion of the optical fiber surrounding the central portion of the optical fiber. The diameter of the circle that best approximates the part.

  The tension members 7, 7a are placed in positions outside the two-core tape cores 5, 5a and the two-core tape cores 5b, 5c in the optical fiber cable 3 in order to protect the weak optical fibers 6-6g. ing.

  The suspension line 2, the optical fiber cable 3, and the connection portion 4 are covered with sheath materials 2b, 3g, and 4a, respectively, and the support wire 2a and the tension members 7 and 7a are in close contact with or adhered to the sheath materials 2b and 3g. Yes. The portion of the optical fiber cable 3 has a rectangular shape, and the upper left notch 3a, the lower left notch 3b, the upper right notch 3c, and the lower right cut into a triangular shape around the two-core ribbons 5, 5a, 5b, and 5c. A notch 3d is provided.

  The upper left notch 3a and the upper right notch 3c are symmetrical with respect to the notch positions, and the two-core tape cores 5 and 5a are inserted between the upper left notch 3a and the upper right notch 3c. Similarly, in the lower left notch 3b and the lower right notch 3d, the incision positions are symmetrical, and the two-core tape cores 5b and 5c are inserted between the lower left notch 3b and the lower right notch 3d.

  The upper left notch 3a and the upper right notch 3c are grooves for providing the upper two-core tape cores 5 and 5a, and the lower left notch 3b and the lower right notch 3d are for providing the lower two-core tape cores 5b and 5c. It is a groove. The upper left notch 3a, the lower left notch 3b, the upper right notch 3c, and the lower right notch 3d make it easy to remove the covering portion when exposing the two-core tape core wires 5, 5a, 5b, and 5c.

  Since the covering portion such as the sheath material 3g can be easily peeled off by the upper left notch 3a, the lower left notch 3b, the upper right notch 3c, and the lower right notch 3d, the two-core tape core wires 5, 5a, 5b, 5c are exposed. It is not necessary to apply much load, and the optical fibers 6 to 6g are rarely broken.

  The connecting portion 4 connects the suspension line 2 and the optical fiber cable 3 with a space therebetween. When the connection portion 4 is viewed in cross section, the width is smaller than that of the suspension line 2 and the optical fiber cable 3, so that the connection portion 4 is cut into a U shape from the left and right.

  FIG. 4 is a cross-sectional view in the case where a tension member is contained in the lower part of the suspension line of the extra length two-core tape type eight-core drop cable according to the present invention. A tension member 7b is inserted below the support line 2a of the suspension line 2 of the extra length 2-core tape type 8-core drop cable 1a.

  In the two-core tape type eight-core drop cable 1a with extra length, the tension members 7, 7a and 7b are in close contact with or adhered to the sheath material 3g when covered with the sheath materials 2b, 3g and 4a, but the support wire 2a is the sheath material. 2b is not adhered or adhered.

  When the support wire 2a is taken out from the suspension wire 2, it is easy to take it out if it is not in close contact with or adhered to the sheath material 2b. In addition, since the tension member 7b is provided, the sheath material 2b is prevented from contracting or extending, and an extra force is applied to the optical fiber cable 3 to increase optical loss or damage the optical fibers 6 to 6g. Can be prevented.

It is a front view of the 2 core tape type 8 core drop cable with extra length which is this invention. It is a top view of the 2 core tape type 8 core drop cable with extra length which is this invention. It is sectional drawing of the 2 core tape type 8 core drop cable with a surplus length which is this invention. It is sectional drawing in case the tension member is contained in the lower part of the suspension line of the 2 core tape type | mold 8 core drop cable with extra length which is this invention. It is a front view of the conventional optical fiber cable with a suspension line. It is sectional drawing of the conventional optical fiber cable with a suspension line.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 2 core tape type 8 core drop cable with extra length 1a 2 core tape type 8 core drop cable with extra length 2 Suspension 2a Support line 2b Sheath material 3 Optical fiber cable 3a Upper left notch 3b Lower left notch 3c Upper right notch 3d Right lower notch 3e Extra length 3f Extra length 3g Sheath material 4 Connection part 4a Sheath material 5 2-core tape core 5a 2-core tape core 5b 2-core tape core 5c 2-core tape core 6 Optical fiber 6a Optical fiber 6b Optical fiber 6c Optical fiber 6d optical fiber 6e optical fiber 6f optical fiber 6g optical fiber 7 tension member 7a tension member 7b tension member 8 optical fiber cable with suspension line 9 suspension line 9a support line 10 optical fiber cable 10a optical fiber 11 connection portion

Claims (2)

  Two cores of the two core tapes laminated in parallel to the long side of the cable cross section are arranged on the upper and lower sides, and the upper and lower two core tape cores of the upper two core tape cores are arranged. After passing the tension member downward, the two-core tape core wire and the tension member are collectively covered with a sheath material in a rectangular shape, and the upper left side of the sheath material in a triangular shape at a position where it contacts the upper two-core tape core wire An optical fiber cable in which a lower left notch and a lower right notch are provided in a triangular shape at a position corresponding to the lower two-core tape core wire, and a suspension wire in which a support wire for suspending the optical fiber cable is covered with a sheath material. A surplus length characterized in that the surplus length is secured to the optical fiber cable and the connection portion is intermittently connected to the suspension line, and the optical fiber cable is connected so as to draw a gentle curve. 2-core tape-type eight-heart drop cable.   2. The extra-length two-core tape type eight-core drop cable according to claim 1, wherein a tension member is passed under the support line of the suspension line.

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