JP2008268461A - Optical cable - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical cable that compactly store and hold the wound part for varying an extra length, that can be protected against being pulled by birds or the like, and that facilitates process such as installation work, extra length adjustment, and transportation. <P>SOLUTION: The optical cables 11, 11' are provided with bodies 12, 12' for which coated optical fibers are covered with a jacket. The optical cables are characterized in that a part of the cable is formed of a winding portion 17 formed by a plurality of winding turns which are wound with a diameter equal to or larger than the allowed curve diameter of the optical fiber, and the winding portion 17 is wound around a winding body 19. And, the winding body 19 is formed so that the outer diameter is equal to or larger than the allowed curve diameter of the optical fiber. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an optical cable used for pulling down from a trunk optical cable to a subscriber's house or the like through a closure.

  With the recent expansion of broadband services such as video distribution, IP telephony, and data communications, the number of subscribers to home-use data communications services (FTTH: Fiber To The Home) using optical fibers is increasing. In this FTTH, for example, an optical cable called a drop optical cable, which is pulled down from an imaginary trunk optical cable to a subscriber's house or the like through a closure, is often used. For example, as shown in FIG. 13, an optical fiber is dropped to a subscriber's house by branching a trunk optical cable laid on a utility pole in a city in a connection box usually called a closure. This is done by connecting the fiber to a drop optical cable.

  In general, a drop optical cable used for pulling down an optical fiber is formed with a small number of cores, one to several optical fibers in the cable. FIG. 14 is a diagram showing an example of a general drop optical cable. The optical cable 1 shown in FIG. 14A has a structure in which a cable body portion 2 having a rectangular cross section and a circular suspension line portion 3 are connected and integrated by a neck portion 4. belongs to. An optical cable 1 ′ shown in FIG. 14 (B) has a structure in which a circular cable body portion 2 ′ having a circular cross section is similarly connected and integrated with a neck portion 4.

  14 (A), tension members 6 are arranged on both sides of an optical fiber core wire 5, and these are formed into a rectangular main body jacket 7 (for example, 3 mm on the long side and 2 mm on the short side). Degree). The optical fiber core 5 is a glass fiber having a standard outer diameter of 125 μm coated with a protective coating having an outer diameter of about 250 μm. The tension member 6 is made of a non-metallic wire material in which a steel wire or high-strength fiber is hardened with a matrix resin. Further, a V-shaped notch 8 is provided on the side surface of the cable main body 2, and the inner optical fiber 5 is taken out by tearing the main body sheath 7 at this notch portion, so that branch connection and terminal formation are easy. It can be done.

14 (B) includes a high-strength fiber 6 ′ such as an aramid fiber around the optical fiber core wire 5 and a main body jacket 7 ′ having a circular cross section (for example, And an outer diameter of about 2 mm). The high-strength fiber 6 'has a function as a buffer for the optical fiber and a tension member.
The suspension wire portion 3 is formed, for example, by covering the outer periphery of a support wire 9 made of a steel wire of about 1.2 mmφ with a suspension wire jacket 10. The main body jackets 7 and 7 'and the suspension jacket 10 are made of the same resin material such as polyethylene, and both are connected together via a narrow neck 4 and are formed together by extrusion molding. .

  Moreover, the indoor optical cable used for indoor wiring can be used in the shape of the cable main body portions 2 and 2 ′ from which the hanging portion 3 of the optical cable is removed. This indoor optical cable is used in an apartment house such as a building for branching an optical fiber from a trunk optical cable drawn into the building and optically wiring it to each house.

  In response to the increasing demand for laying optical cables, it is desired to speed up the laying work using drop optical cables and indoor optical cables. In the case of a pull-down work from an imaginary trunk optical cable, it is often performed in a poor working environment such as on a power pole or a bucket car, and the cable is cut to a predetermined length and the optical fiber core wire is connected from the inside of the cable. The operation of taking out and reinforcing the optical fibers by fusion splicing is not easy and takes time. For this reason, there is a method of reducing work at the site by attaching optical connectors in advance to both ends of the optical cable cut to a predetermined length.

In this case, optical connectors are attached to both ends of the optical cable in advance to improve the efficiency of connection work, and a curl portion is provided in the optical cable to make the extra length variable so as to absorb an error in the installation length (for example, Non-Patent Document 1). reference). In addition, there is a method for simplifying the installation work by curling the entire length of the optical cable, winding it around an existing suspension line, and laying it by pulling in the longitudinal direction (see, for example, Patent Document 1).
JP-A-2005-292205 Kunihiro Toge, and two others, “Optical cable technology that enables effective use of circuit board maintenance”, NTT Technical Journal, Telecommunications Association, December 2006, p. 64-65

However, the optical cable disclosed in Non-Patent Document 1 is intended for laying in underground pipes including manholes, but there is a specific disclosure about the protection and storage of the curled portion for varying the extra length. Not done.
In addition, the optical cable disclosed in Patent Document 1 is an optical cable that does not have a hanging line part, and is an optical cable that can be pulled down from an aerial, but a curl part is wound around a wire material such as a cable or a hanging line already installed between utility poles. Installed. Since this optical cable is curled over its entire length, it requires winding work around a pre-installed suspension line, and the curl stretches and bends during transportation, and is deformed and scattered by receiving side pressure. The problem in handling such as remained.

  If the curled optical cable is simply supported by an aerial suspension line, etc., there is a risk of adhesion of ice and snow, bending or cutting due to external pressure, and there is a risk of friction caused by vibration or vibration due to wind pressure and injury. . In addition, crows and other birds curled and slackened as a nest-building material, and may be pulled or played. There is also a problem.

  The present invention has been made in view of the above-described circumstances, and the winding portion for changing the extra length can be stored compactly and protected from being pulled by birds, etc. An object of the present invention is to provide an optical cable that can be easily handled such as transportation.

  An optical cable according to the present invention is an optical cable having a main body part in which an optical fiber core wire is covered with a jacket, and a part of the optical cable is wound from a plurality of winding turns wound with a diameter larger than an allowable bending diameter of the optical fiber. It is formed by the winding part which becomes, and this winding part is wound by the winding body, It is characterized by the above-mentioned. The outer diameter of the wound body is preferably formed to be equal to or larger than the allowable bending diameter of the optical fiber.

  The wound body may be supported by inserting a suspension line in the axial direction. In this case, the wound body is a cylinder, and it is preferable to provide a slit that can be attached to and detached from the hanging line from the side. By providing the slit, it is possible to easily remove the wound body from the wound portion regardless of whether the hanging line is inserted through the wound body. Further, a plurality of projections are provided in the axial direction at predetermined intervals on the outer surface of the wound body to increase the holding and restraining force of winding of the winding portion, and further, the interval between the projections is set to 5 to 5 times the diameter of the cable body. You may make it easy to extend by forming 10 times.

  Further, the wound body may have a tapered shape that becomes narrower toward the extending side of the wound portion, so that the optical cable can be easily extended. In addition, a notch is provided in the circumferential direction so that it can be easily cut at predetermined intervals in the axial direction of the wound body, or the wound body is formed of a plurality of cylindrical bodies that can be divided in the axial direction. In addition to the length of the winding body, the remaining winding body after the winding portion is stretched may be partially removed.

  According to the present invention, the winding portion for the extra length that absorbs the error in the installation length of the optical cable eliminates the variation of the winding turn by the wound body, and the winding portion is stretched or bent during transportation, It is possible to prevent deformation due to side pressure. Moreover, after laying the optical cable, it is possible to minimize the wound portion from being damaged by birds.

  Embodiments of the present invention will be described with reference to the drawings. FIG. 1A is a diagram for explaining a cable drawing form using an optical cable according to the present invention, and FIG. 1B and FIG. 1C are diagrams showing a configuration example of an optical cable used in the present invention. In the figure, 11 and 11 'are optical cables, 12 and 12' are main body parts, 13 is a hanging line part, 14 is a neck part, 15 is a connected and integrated part, 16 is a separated part, 17 is a wound part, and 18 is light. A connector 19 indicates a wound body.

  As shown in FIG. 1B, the optical cable 11 used in the present invention does not have, for example, an optical cable having a rectangular cable cross section similar to that described in FIG. It is an optical cable. Although detailed description of the optical cable 11 is omitted, the main body 12 of the cable has tension members disposed on both sides of one or more optical fiber cores, and these are formed into a main body jacket (for example, a long side) having a rectangular cross section. 3 mm, about 2 mm on the short side). The optical fiber core is obtained by coating a glass fiber having a standard outer diameter of 125 μm with a protective coating having an outer diameter of about 250 μm. The tension member is formed of a non-metallic wire material in which a steel wire or high-strength fiber is hardened with a matrix resin. Further, the side surface of the main body 12 of the cable may be provided with a V-shaped notch for tearing, but may have a shape not having a notch.

  Further, as another optical cable 11 ′ used in the present invention, as shown in FIG. 1C, an optical cable having a circular cable cross section similar to that described in FIG. 14B. Although a detailed description of the optical cable 11 ′ is omitted, the main body 12 ′ of the cable is provided with a high-strength fiber such as an aramid fiber around the optical fiber core wire, and the main body 12 For example, the outer diameter is about 2 mm). The high-strength fiber has a function as a buffer and tension member for the optical fiber core wire.

  The suspension line portion 13 of the optical cables 11 and 11 ′ is formed, for example, by covering the outer periphery of a steel wire or the like of about 1.2 mmφ with a suspension line jacket. The outer cover of the main body parts 12 and 12 ′ and the outer cover of the hanging line part 13 are collectively formed by extrusion molding using the same resin material such as polyethylene, and the main body parts 12 and 12 ′ and the hanging line part 13 are thin. They are connected and integrated through a width neck 14. Therefore, although the main body parts 12 and 12 'and the hanging line part 13 are connected and integrated, the neck part 14 can be easily separated by cutting by hand as necessary.

  As shown in FIG. 1A, the optical cable according to the present invention is used as, for example, a drop optical cable that draws an optical fiber from a trunk optical cable C installed on a utility pole P to a house H or the like. The optical fiber from the trunk optical cable C is branched by the closure K, and the optical cables 11 and 11 'are optically connected to the branched optical fiber. The optical cables 11 and 11 ′ are composed of a part 15 in which the main body parts 12 and 12 ′ and the hanging line part 13 are connected and integrated, and a part 16 in which the main body parts 12 and 12 ′ and the hanging line part 13 are separated. A cylindrical winding portion 17 for extra length is formed in the main body portions 12 and 12 ′ of the separated portion 16. FIG. 1A illustrates a case where the hanging line is not inserted through the winding portion. The winding portion 17 is held by a winding body 19 described later. The wound body 19 is fixed to the suspended wire portion 13 by a clamp member or the like which will be described later, or by inserting the suspended wire portion 13 through the wound body 19.

  The hanging portion 13 is attached along the laying path of the optical cable by attaching the fixture R using the existing trunk optical cable C and other structures. When the spiral hanger S is installed in the existing trunk optical cable C, the optical cables 11, 11 'may be installed using this. The optical cables 11, 11 'are cut in advance to a predetermined length, and it is desirable to shorten the installation work by attaching an optical connector 18 to at least one end of the optical cables. The optical connector 18 can be attached at the work site, but may be prepared in a state of being attached in advance.

  The winding portion 17 and the wound body 19 that winds and supports the winding portion 17 are laid so as to be close to the cable termination side of the house side H in FIG. 1A, but are close to the closure K side. It can also be laid. This is due to the difference in which of the portion 15 where the main body portions 12, 12 ′ are connected and integrated and the portion 16 where the main body portions 12, 12 ′ are separated is connected to the closure K side. Considering the situation, etc., it is determined by the selection of the starting point when laying. Moreover, the position of the winding part 17 and the winding body 19 which winds and supports this may be changed depending on whether the optical cable is extended from the winding part 17 from either the left or right direction or both. it can.

  The winding body 19 is moved to the house H along the hanging portion 13 stretched first while extending the wound portion 17 that is wound, and then held at a predetermined position by a clamp member or the like described later. Fix it. The optical cable that has been stretched and slackened from the winding portion 17 is fastened to the hanging portion 13 by the binding tool T. Moreover, the optical connector 18 attached in advance to the moving direction end side of the winding portion 17 is inserted into a connection adapter or the like in a connection box of the house H. In addition, in order to change the laying direction by pulling down to the house H, the hanging line part 13 cut | disconnects a continuous hanging line in an intermediate part, and is laid in linear form between the houses H. Moreover, the suspended line part 13 can also use what was prepared separately.

  FIG. 2 is a diagram for explaining another cable pull-down configuration using the optical cable according to the present invention. FIG. 2A illustrates a form in which the hanging line is not inserted through the winding portion. In this case, the optical cable of the winding portion 17 is stretched while being spirally wound around the suspension line portion 13, and the wound body 19 moves while turning around the suspension line portion along the suspension line portion 13 as in the example of FIG. 1. It is an example of holding and fixing with a clamp member or the like in a stretched state. FIG. 2A shows a state in which the stretching is completed and the clamp member is fixed.

  In the form shown in FIG. 2 (B), the suspended wire portion 13 is inserted into the wound body 19, the wound body 19 is moved along the suspended wire portion 13, and the optical cable of the wound portion 17 is placed on the suspended wire portion 13. This is an example in which it is stretched so as to be wound in a spiral shape. In this laying configuration, by moving the winding body 19 with the suspension line portion 13 as a guide, the optical cable of the winding portion 17 wound around the outer periphery of the winding body 19 is automatically pulled out, and the suspension line portion 13. Wrapped on top. The wound body 19 is held and fixed by fixing both ends to the hanging portion. Note that FIG. 2B shows a state in which the stretching is completed and the clamp member is fixed.

  FIG. 3 is a diagram illustrating an example of an optical cable according to the present invention. The optical cable shown in FIG. 3A is an example in which a winding portion 17 is provided as an extra length in a part of an optical cable that does not have the hanging portion 13. The optical cable shown in FIG. 3B is an example in which a winding portion 17 is provided with an extra length in the optical cable of a portion 16 in which the main body portions 12 and 12 ′ are partly separated from the hanging wire portion 13. A part of the optical cable main body 12, 12 ′ is wound around the outer periphery of the cylindrical winding body 19 in a cylindrical shape to form a winding portion 17. The winding portion 17 of the optical cable may have a winding turn formed in advance by curling as will be described later.

The winding portion 17 is held by using a tightening band or the like (not shown) at the time of storage or transportation so that the winding portion 17 does not come off from the winding body 19 or come apart. When the required length of the optical cable is to be extended by laying the optical cable or the like, the tightening band or the like is loosened or removed and fed out from the wound body 19.
The wound body 19 is formed in a cylindrical shape with a lightweight alloy such as plastic or aluminum. Further, both ends of the wound body 19 may be in a released state, but it is desirable to attach a lid member 20 so that insects and birds do not enter inside to form a nest.

The winding portion 17 is wound with a diameter equal to or larger than the allowable bending diameter of the optical cable. For this reason, it is preferable that the wound body 19 is formed so that the outer diameter is equal to or larger than the allowable bending diameter of the optical cable.
In addition, it is desirable that the winding portion 17 is kept below a transmission loss that causes a practical problem in a state where the winding portion 17 is extended. For example, it is preferable to use an optical fiber having a bending loss of 0.5 dB / 10 turns or less at a bending diameter of 30 mm at a wavelength of 1.55 μm. Further, it is preferable to use an optical fiber having an allowable bending diameter such that a bending loss at a bending diameter of 15 mm at a wavelength of 1.55 μm is 0.5 dB / 10 turns or less.

  For example, an optical fiber having a mode field diameter (MFD) of 9.0 μm or less as defined by Petermann-I at a wavelength of 1.3 μm is used as the optical fiber of the optical cable that satisfies the above conditions. It is preferable. Furthermore, by setting the mode field diameter at a wavelength of 1.55 μm to 8.0 μm, it becomes possible to suppress the microbend and bending loss due to the side pressure and reduce the allowable bending diameter.

From the above points, the bending diameter D of the optical cables 11, 11 ′ is set to about 30 mm, for example. In this case, the length L of the winding portion 17 on the cylinder can be set to about 1 m (about 300 turns), for example, so that an extra length of about 20 m can be obtained.
Returning to FIGS. 1 and 2, the laying distance of the optical cables 11 and 11 ′ by pulling from the imaginary trunk optical cable C to the house H is, for example, about 45 to 50 m. In this case, the portion 15 where the main body portions 12, 12 ′ and the hanging wire portion 13 are connected and integrated is about 40 m, and the portion 16 where the main body portions 12, 12 ′ and the hanging wire portion 13 are separated is about 10 m. It is wound in a cylindrical shape to make the extra length. In addition, it is preferable to attach the optical connector 18 to both ends of the main body portions 12 and 12 ′.

  Although the winding part 17 can hold | maintain a winding state using said winding body 19 by this invention, other binding ties, etc., a winding turn cross | intersects only by winding. In some cases, it is difficult to align and hold the cylindrical body until the both ends are held and fixed after being wound around the winding body 19. Therefore, as shown in FIG. 4, the winding portion 17 that is the extra length of the optical cable is curled into a cylindrical shape, and the curled winding turn is wound on the wound body 19. It may be.

  In the curling process, the main body parts 12 and 12 ′ having no curl are aligned and wound at a predetermined diameter (greater than the allowable bending diameter of the optical cable) using a cylindrical winding jig 40. Next, the main body 12, 12 ′ including the outer cover part is heat-treated by the heating device 41, and the entire body parts 12, 12 ′ are curled and arranged so that the winding turns of the winding part 17 are aligned in a cylindrical shape. Hold. The curled cylindrical winding portion 17 can be expanded and contracted like a coil spring along the axial direction. As the heating unit 41a, various methods such as heater heating and infrared heating can be used.

  In addition, in the optical cable 11 as shown in FIG. 1B, when a steel wire is used for the tension member of the main body 12, the tension member is not curled by heating to the extent that the resin is curled. It is difficult to hold. For this reason, the optical cable 11 is, for example, a cable formed of a nonmetallic tension member using FRP in which high-strength fibers are hardened with a matrix resin.

  FIG. 5 and FIG. 6 are diagrams for explaining a configuration example of preventing the winding portion 17 from being scattered and holding and fixing the wound body 19 described with reference to FIG. 1 (A) or FIG. 2 (A). FIG. 5A shows an example in which both ends of the wound body 19 are held by the clamp members 22 a and 22 b and the screw member 23 and are suspended and supported by the hanging line portion 13. The clamp members 22a and 22b are made of metal or hard plastic. The left clamp member 22a is formed, for example, so as to hold the hanging line portion 13, the optical cable main body portions 12 and 12 ', and the wound body 19 in a line. Further, the right clamp member 22b holds the hanging wire portion 13 and the wound body 19 in a line, and the optical cable main body portions 12 and 12 'are formed so as to be held by the side surface of the wound body 19. Good.

  In addition, although the clamp member 22a, 22b showed the example using a different shape in the cable extension direction of the left side, and the moving direction of the right side winding body 19, the thing of the same shape of right and left may be used. . When the cable is extended or the winding body 19 is moved, the clamp member is once removed, and after the extension is finished and the winding body is moved to the fixing position, the winding body and the suspension portion are fixed again with the clamp member, and the optical cable is connected. Grip with the clamp member. Alternatively, when extending or moving the winding body, the screw member 23 is loosened to release the holding and fixing state of the main body portions 12 and 12 'and the winding body 19, and the predetermined cable extension and movement of the winding body are completed. In this case, the screw member 23 is tightened again to prevent the winding portion 17 from being scattered and the winding body 19 is held and fixed.

  FIG. 5 (B) is an example in which both ends of the wound body 19 are held by binding members 24 a and 24 b such as insulation locks and are suspended and supported by the hanging line portion 13. The binding members 24a and 24b are made of flexible plastic. The left bundling member 24a has, for example, a shape that binds the hanging wire part 13, the optical cable main body parts 12 and 12 ', and the wound body 19 in a line, and the right bundling member 24b is a hanging line part. 13 and the winding body 19 are held in a line, and the main body portions 12 and 12 ′ of the optical cable are formed so as to be held by the side surface of the winding body 19.

  In addition, it is the same as that of the case of FIG. 5 (A) that you may use the same shape for the bundling members on the left and right sides. When the cable is extended or the winding body 19 is moved, the holding members 24a and 24b are cut or loosened to release the holding and fixing state of the main body portions 12 and 12 'and the winding body 19, and a predetermined cable extension is performed. When the movement of the wound body is finished, the wound members are bound again by the binding members 24a and 24b, and the winding portion 19 is prevented from being scattered and the wound body 19 is held and fixed.

  In FIG. 6A, the support bar member 25 is inserted into the wound body 19, and the bar portions protruding from both ends of the wound body 19 are held by the clamp members 26 a and 26 b and the screw member 23. It is an example which makes it suspend and support. The clamp members 26a and 26b are formed of metal or hard plastic as in the example of FIG. The left clamp member 26a is formed, for example, so as to hold the hanging line portion 13, the optical cable main body portions 12 and 12 ', and the bar member 25 in a line. Further, the right clamp member 26b holds the hanging line portion 13 in a line with the bar member 25, and the optical cable main body portions 12 and 12 'are separately held on the side surface of the wound body 19 by a binding member 27. May be.

  In addition, it is the same as that of the case of FIG. 5 (A) that you may use the same shape for the clamp members on both the left and right sides. When the cable is extended or the winding body 19 is moved, the clamp members 26a and 26b are loosened by the screw member 23 to release the holding and fixing state of the main body portions 12 and 12 'and the winding body 19, and the predetermined cable extension is performed. When the movement of the winding body is completed, the screw member 23 is tightened again to prevent the winding portion 17 from being scattered and the winding body 19 is held and fixed.

  In FIG. 6B, the support bar member 25 is inserted into the wound body 19, and the bar portions protruding from both ends of the wound body 19 are held by the binding members 28 a and 28 b such as an insulok. It is an example which makes it suspend and support. The binding members 28a and 28b are made of flexible plastic. For example, the binding member 28a on the left side has a shape that binds the hanging wire part 13, the optical cable main body parts 12 and 12 ', and the wound body 19 in a line, and the right binding member 28b has the hanging wire part 28b. 13 and the wound body 19 may be held in a line, and the optical cable main body portions 12 and 12 ′ may be separately held on the side surface of the wound body 19 by a binding member 27.

  In addition, it is the same as that of the case of FIG. 5 (A) that you may use the same shape for the bundling members on the left and right sides. When the cable is extended or the winding body 19 is moved, the binding members 28a and 28b are cut or loosened to release the holding and fixing state of the main body portions 12 and 12 'and the winding body 19, and the predetermined cable extension is performed. When the movement of the winding body is finished, the winding members are bound again by the binding members 28a and 28b, and the winding portion 19 is prevented from being scattered and the winding body 19 is held and fixed.

  FIG. 7 is a diagram illustrating a configuration example of preventing the winding portion 17 from being scattered and holding and fixing the wound body 19 described with reference to FIG. In this example, the wound body 19 is inserted through and supported by the hanging portion 13, the wound body 19 is moved along the hanging portion 13, and the optical cable of the winding portion 17 is spirally formed on the hanging portion 13. This is an example in which it is stretched so as to be wound around. In this example, by moving the winding body 19 with the suspension line portion 13 as a guide, the optical cable of the winding portion 17 wound around the outer periphery of the winding body 19 is automatically pulled out and the suspension line portion 13 is Wrapped around.

  The wound body 19 is held and fixed by fixing both ends to the hanging portion 13. In the example of FIG. 7, the lid member 20 described with reference to FIG. 3 is attached, and when the extension is completed, the lid member 20 can be fixed to the suspension line portion 13 by bonding. In addition, an insertion pipe may be arranged in advance between the lid members 20 on both sides so that the hanging line portion 13 can be easily inserted into the hole 20a. In addition, a bundling member 27 such as an insulation lock similar to that used in FIG.

  8-12 is a figure explaining various embodiment of the wound body by this invention. FIG. 8 shows an example in which a slit 31 is inserted in the axial direction of the cylindrical wound body 19a. The slit 31 inserted in the axial direction is normally closed by the elasticity of the wound body 19a. However, the slit 31 can be opened by pushing it open in the arrow direction against the elastic force of maintaining the cylindrical shape. . By opening the slit 31, the hanging portion 13 can be inserted into or taken out of the wound body 19a from the side.

  Accordingly, in FIG. 2B, the wound body 19a can be easily inserted into or removed from the suspension line 13 even when both ends of the suspension line 13 are fixed and stretched to a structure or the like. Further, as shown in FIG. 8C, by placing one end of the slit 31 inside the wound body 19a, the outer diameter of the wound body 19a can be reduced, and the wound body 19a is wound. It can be made to be easily detachable from the turning portion 17. This form of providing the slit 31 can also be applied to FIGS. 9, 10 </ b> A and 10 </ b> B, which will be described below, and the wound bodies 19 c and 19 d 19 f shown in FIG. 12.

  FIG. 9A shows an example in which a taper portion 32 is provided on the side of the wound body 19b where the cable is extended. In this example, when the winding portion wound on the wound body 19b is extended, the optical cable can be smoothly drawn out to facilitate the extension. Further, when the optical cable is stretched, it is possible to reduce damage caused by rubbing or damaging the optical cable at the end edge of the wound body.

  FIG. 9B shows an example in which the entire wound body 19b 'is configured with a tapered portion 32'. In this case, the wound body 19b 'is narrowed toward the extending side, and the outer diameter of the tip portion where the attached body 19b' is the thinnest is made larger than the allowable diameter of the optical fiber. The winding portion 17 can be wound around a portion that is not the tapered portion 32 of the wound body 19b in FIG. 9A, or can be wound around the tapered portion of the wound body in FIGS. 9A and 9B. You can also. The form in which the tapered portions 32 and 32 'are provided can be applied to the shape in which the slits in FIG. 8 are provided, and can also be applied to the form in FIG.

  FIG. 10A shows an example in which the protrusions 33 are continuously provided along the axial direction of the wound body 19c. The protrusions 33 are provided in at least one row on the outer surface of the wound body 19c at an interval in which at least one optical cable 12, 12 'is inserted. The optical cables 12 and 12 ′ are wound on the wound body 19 c so as to be accommodated in the space portion 33 a between the projecting portions 33. Each winding turn of the winding portion is restrained from moving in the axial direction and is held at a predetermined interval without intersecting the winding turns.

  FIG. 10B shows an example in which the protrusions 33 are provided at a distance from the example of FIG. 10A along the axial direction of the wound body 19d. In this example, the interval between the protrusions 33 can accommodate about 5 to 10 optical fibers. By putting a plurality of optical cables together in the protruding portion 33, it is possible to make it easier to extend the optical cable than in the case of putting one optical cable in FIG. However, since the holding and restraining force of the winding turn is somewhat lower than in the case of FIG. 10A, for example, a protruding piece 33a may be provided on the top of the protrusion 33.

  FIG. 11 shows an example in which the wound body 19e is divided into a plurality of short cylindrical bodies 34 along the axial direction. The end portion of the short cylindrical body 34 is formed with a coupling portion 35 that can be attached to and detached from each other, and by connecting an arbitrary number of cylindrical bodies 34, a wound body 19e having an arbitrary length can be obtained. For example, the coupling portion 35 includes a male portion 35a and a female portion 35b that can be fitted to each other, and can be configured to be integrated by fitting rotation. As described above, the length of the wound body 19e can be changed, and the extra length of the optical cable can be selected at an arbitrary length. Further, when the remaining amount of the winding portion is reduced by extending the cable, it is possible to shorten the winding body 19e by removing an appropriate number of the cylindrical bodies 34.

  FIG. 12 shows an example in which notches 36 are provided in the circumferential direction at predetermined intervals along the axial direction of the wound body 19f. For example, the circumferential notch 36 has a V-shaped notch cross section, and can be easily cut by cutting with a cutter or the like. The wound body 19f can be obtained by breaking a long pipe-shaped object at the circumferential notch 36 to obtain a wound body 19f having a desired length. Further, when the remaining amount of the winding portion is reduced by extending the cable, the winding body 19e can be shortened similarly to the case of FIG. 11 by cutting with the circumferential notch 36 at an appropriate location. .

It is a figure explaining the outline of embodiment of this invention. It is a figure explaining the outline of other embodiment of this invention. It is a figure explaining an example of the optical cable by this invention. It is a figure explaining an example which performs a curl process to the optical cable in this invention. It is a figure explaining the structural example which makes the suspension part support the winding prevention and the winding body of the winding part in this invention. It is a figure explaining the other structural example which makes the suspension line part support the winding part prevention and winding body in this invention. It is a figure explaining the structural example which penetrates a hanging line part in the wound body in this invention. It is a figure explaining the structural example of the wound body in this invention. It is a figure explaining the other structural example of the wound body in this invention. It is a figure explaining the other structural example of the wound body in this invention. It is a figure explaining the other structural example of the wound body in this invention. It is a figure explaining the other structural example of the wound body in this invention. It is a figure explaining the pulling-down method of the conventional optical cable. It is a figure explaining the structural example of the conventional drop optical cable.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11, 11 '... Optical cable, 12, 12' ... Main-body part, 13 ... Hanging line part, 14 ... Neck part, 15 ... Connection integrated part, 16 ... Separated part, 17 ... Winding part, 18 ... Optical connector, 19 , 19a to 19f ... Wound body, 20 ... Lid member, 22a, 22b, 26a, 26b ... Clamp member, 23 ... Screw member, 24a, 24b, 27, 28a, 28b ... Bundling member, 25 ... Bar member, 31 ... Slit, 32, 32 '... taper portion, 33 ... projection, 34 ... short cylindrical body, 35 ... coupling portion, 36 ... circumferential notch.

Claims (9)

  An optical cable having a main body part coated with an optical fiber core, and a part of the optical cable is formed by a winding portion composed of a plurality of winding turns wound with a diameter larger than the allowable bending diameter of the optical fiber. An optical cable, wherein the wound portion is wound around a wound body.   The optical cable according to claim 1, wherein an outer diameter of the wound body is equal to or larger than an allowable bending diameter of the optical fiber.   The optical cable according to claim 1, wherein a suspension line is inserted in an axial direction of the wound body.   The optical cable according to claim 3, wherein the wound body is provided with a slit that can be attached and detached from a side of the suspension line.   The optical cable according to any one of claims 1 to 4, wherein a plurality of protrusions are provided in an axial direction at predetermined intervals on an outer surface of the wound body.   The optical cable according to claim 5, wherein an interval between the protrusions is 5 to 10 times a diameter of the main body portion of the cable.   The optical cable according to any one of claims 1 to 6, wherein a taper is provided on an end of the wound portion of the wound body on the extending side.   The optical cable according to any one of claims 1 to 4, wherein an annular notch that can be easily cut is provided at a predetermined interval in the axial direction of the wound body.   The optical cable according to any one of claims 1 to 3, wherein the wound body is formed of a plurality of short cylindrical bodies that can be divided in the axial direction.

Images