JP2016080843A - Optical cable and method for fabricating optical cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical cable formed by a winding upper-winding tape strongly connected together in a longitudinal direction, and a method for fabricating the optical cable.SOLUTION: The optical cable includes: a cable core having a plurality of optical fibers; an upper-winding tape wounded around the circumference of the cable core; and a sheath covering the circumference of the upper-winding tape. The upper-winding tape has a connection part 16j, which is made by overlapping the ends of the tape in a longitudinal direction (ends of upper-winding tape materials 16p, 16q) and melting and joining the ends together.SELECTED DRAWING: Figure 3A

Description

  The present invention relates to an optical cable having a plurality of optical fiber core wires, and an optical cable manufacturing method for manufacturing the optical cable.

  With the recent expansion of broadband services such as video distribution, IP (Internet Protocol) telephone, and data communication, the number of subscribers to home-use data communication service (FTTH: Fiber To The Home) via optical fiber cable (optical cable) has increased. doing.

  In such an optical cable, an upper winding tape is wound around the outer periphery of a cable core having a plurality of optical fiber core wires spirally (horizontal winding) or vertically attached, and a sheath (also referred to as a jacket) is applied to the outer periphery. . In addition, as the winding method of the upper winding tape, in order to improve disassembling property (improvement of tape core wire take-out property) and productivity, vertical attachment is sometimes used instead of horizontal winding.

Such an optical cable and its manufacturing method are described in, for example, Patent Document 1 and the like. In the manufacturing method described in Patent Document 1, a presser winding tape (upper tape) is vertically attached to the slot body and introduced into the former.
Patent Document 2 discloses an ultrasonic welding apparatus for ultrasonic welding a fibrous mat such as a nonwoven fabric to the surface of a resin molded product.

Japanese Patent Laid-Open No. 2004-12915 JP 2011-110839 A

  The conventional upper winding tape as described in Patent Document 1 is installed by being wound around the upper winding tape supply bobbin in the production line, and is drawn out therefrom and wound around the cable core in the vertical or horizontal winding. In order to prevent the production line from being stopped for as long as possible, the upper winding tape supply bobbin is wound with an upper winding tape in which the ends of a plurality of upper winding tape materials are connected to each other and lengthened. .

  The state of this connecting portion will be described with reference to FIGS. 4A and 4B. 4A is a cross-sectional view in the thickness direction of the connection portion, and FIG. 4B is a top view showing a state in which the connection portion in FIG. 4A is removed. As shown in FIG. 4A, the end portion (length d2 portion) of the upper tape material 16q and the end portion (length d3 portion) of the upper tape material 16p are adhered to the end portion (length d1 portion). Tape 16r is used. Here, the upper winding tape materials 16p and 16q are non-woven fabrics, and the adhesive tape 16r is obtained by attaching an adhesive to a white cloth tape, and is more rigid and harder than the upper winding tape materials 16p and 16q. The adhesive tape 16r is bonded such that d1 is slightly longer than d2 + d3, and the thickness h of the connecting portion is the sum of the thickness of the adhesive tape 16r and the thickness of the upper tape material 16p (16q).

  As described above, in the conventional connection method, the adhesive tape 16r has high rigidity and is harder than the upper tape material 16p, 16q. Therefore, particularly when the cable core is wrapped in the former when vertically attached, the connection portion ( The overlapping portion) is easily opened, and the thickness h of the connecting portion is increased by the thickness of the adhesive tape 16r. Therefore, such a connecting portion is caught when passing through the former, and is easily broken as shown in FIG. 4B. In order to obtain adhesive strength, the length d1 of the pressure-sensitive adhesive tape 16r needs to be increased to, for example, 60 mm. However, it is still easy to open and break. In addition, the arrow in FIG. 4B points out the advancing direction of the upper winding tape in a production line. Even when the strength of the connection portion is confirmed by a tensile test or the like regardless of vertical attachment or horizontal winding, it may break along the pass line from the upper tape supply bobbin to the former.

  Such a breakage makes it impossible to wrap the cable core, and the production of the optical cable is stopped. As described above, in the conventional connection method, as a result, it is impossible to manufacture a long length, and productivity is deteriorated.

  The present invention has been made in view of the above-described actual situation, and an object of the present invention is to make the longitudinal connection between the upper tapes stronger when manufacturing an optical cable wound with the upper tape. .

  An optical cable according to the present invention is an optical cable comprising a cable core having a plurality of optical fibers, an upper winding tape wound around the outer periphery of the cable core, and a sheath covering the outer periphery of the upper winding tape, The upper winding tape has a connection portion that is melt-bonded by overlapping end portions in the longitudinal direction.

  An optical cable manufacturing method according to the present invention manufactures an optical cable including a cable core having a plurality of optical fibers, an upper winding tape wound around the outer periphery of the cable core, and a sheath covering the outer periphery of the upper winding tape. An optical cable manufacturing method for the above-mentioned method, wherein the longitudinal ends of a plurality of upper-winding tape materials are overlapped and melt-bonded to form a joining step that constitutes the upper-winding tape, and the upper-winding tape is attached after the joining step. A winding step of winding around a reel, and a winding step of winding around the outer periphery of the cable core while feeding the upper winding tape from the reel.

  According to the present invention, when the optical cable wound with the upper winding tape is manufactured, the longitudinal connection between the upper winding tapes can be strengthened.

It is a figure which shows one structural example of the optical cable which concerns on one Embodiment of this invention. It is a figure which shows the other structural example of the optical cable which concerns on one Embodiment of this invention. It is a figure which shows an example of the manufacturing line of the optical cable of FIG. 1A. It is sectional drawing of the thickness direction which shows the mode of the connection part of the upper volume tape connected with the connection method which concerns on one Embodiment of this invention. It is sectional drawing of the thickness direction which shows a mode that the connection part of FIG. 3A was actually connected. It is a top view which shows the connection part of the upper winding tape of FIG. 3B. It is sectional drawing of the thickness direction which shows the mode of the connection part of the upper winding tape connected with the conventional connection method. It is a top view which shows a mode that the connection part of the upper winding tape of FIG. 4A removed.

[Description of Embodiment of the Present Invention]
First, embodiments of the present invention will be listed and described.
(1) An optical cable according to an embodiment of the present invention includes a cable core having a plurality of optical fibers, an upper winding tape wound around the outer periphery of the cable core, and a sheath covering the outer periphery of the upper winding tape. In the optical cable, the upper winding tape has a connection portion that is melt bonded by overlapping end portions in the longitudinal direction. Thereby, when manufacturing the optical cable which wound the upper winding tape, the connection of the longitudinal direction of upper winding tapes can be strengthened.

  (2) In the optical cable of (1), the connection portion is locally melt-bonded at a plurality of locations in a region where the end portions are overlapped. Thereby, it can melt-connect easily and firmly.

  (3) In the optical cable of (1) or (2) above, the connecting portion has a length in the longitudinal direction of the upper winding tape of 10 mm or less, and a tensile breaking strength at a tensile speed of 20 mm / min is 120 N / 30 mm or more. It is. Thereby, it can melt-connect still more firmly and a manufacturing speed can be raised.

  (4) An optical cable manufacturing method according to an embodiment of the present invention includes a cable core having a plurality of optical fibers, an upper winding tape wound around the outer periphery of the cable core, and a sheath covering the outer periphery of the upper winding tape. An optical cable manufacturing method for manufacturing an optical cable provided with a joining step for forming the upper winding tape by stacking and melting and joining longitudinal ends of a plurality of upper winding tape materials, and the joining step Thereafter, a winding step of winding the upper winding tape around a reel, and a winding step of winding the upper winding tape around the cable core while feeding the upper winding tape from the reel. Thereby, when manufacturing the optical cable which wound the upper winding tape, the connection of the longitudinal direction of upper winding tapes can be strengthened.

[Details of the embodiment of the present invention]
Hereinafter, specific examples of an optical cable and an optical cable manufacturing method according to embodiments of the present invention will be described with reference to the accompanying drawings.

  First, a configuration example of an optical cable (also referred to as an optical fiber cable) according to an embodiment of the present invention will be described with reference to FIGS. 1A and 1B. 1A is an example of a slot type optical cable, and FIG. 1B is an example of a slotless type optical cable, both of which are frequently used for trunk lines, but the use of the optical cable according to the present embodiment is not limited to this. Absent. Moreover, the structure of the optical cable manufactured in this embodiment and the cable core inside the optical cable are not limited to those illustrated.

  The optical cable 1 illustrated in FIG. 1A includes a cable core 11 having a plurality of optical fiber cores 12 and an upper winding tape (also referred to as a press-winding tape) 16 that is wound vertically around the outer periphery of the cable core 11. Further, in the optical cable 1, the coarsely wound string 17 is wound around the outer periphery of the upper wound tape 16 and then covered with the sheath 18. The sheath 18 covers the outer side of the upper winding tape 16 wound around the outer periphery of the cable core 11 so that the cross-sectional shape of the optical cable 1 becomes a round shape, and is made of, for example, PVC (polyvinyl chloride), polyethylene, or the like. do it.

  The cable core 11 has a slot rod (also referred to as a spacer rod) 13 made of a plastic material in which a tension member (also referred to as a tensile body) 14 such as a steel wire is embedded and integrated at the center and a plurality of grooves 13a are provided on the outer periphery.

  A groove (slot groove) 13a of the slot rod 13 is formed in a spiral shape or an SZ shape, and a plurality of optical fiber core wires 12 are accommodated in the groove 13a. Here, the optical fiber core wire 12 is not limited to a single core, and may be a tape-shaped optical fiber core wire as illustrated. Moreover, when installing the optical cable 1 in the place which needs to pull out the optical fiber core wire 12 in the tensioned state, it is preferable that the groove 13a is formed in an SZ shape.

  Further, the cable core 11 has a rough winding string 15. The coarsely wound string 15 is wound around the outer periphery of the slot rod 13 in a state where the optical fiber core 12 is accommodated in the groove 13a, and is held so that the optical fiber core 12 accommodated in the groove 13a does not fall off. Yes. In addition, when the groove | channel 13a is helical, the rough winding string 15 may be abbreviate | omitted.

  On the outer periphery of the cable core 11, an upper winding tape 16 is wound longitudinally in the longitudinal direction. When the rough winding string 15 is provided, the upper winding tape 16 is wound from above. When winding, the one end surface 16c side in the width direction is overlapped on the surface, so that the overlapping portion (the overlapping portion 16a on the upper layer side and the overlapping portion 16b on the lower layer side) is formed.

  In this way, the upper winding tape 16 holds the optical fiber core wire 12 accommodated in the groove 13a so that it does not jump out (so as not to be scattered), and the sheath 18 is formed by resin extrusion. At this time, the resin can function as a contact suppression layer that suppresses the resin from falling on the surface of the optical fiber core wire 12 and coming into contact therewith, or as a heat insulating layer during extrusion of the sheath 18.

  As the upper tape 16, for example, a nonwoven fabric made of fibers of polyester, polyethylene, polypropylene, or the like is used. Moreover, the upper tape 16 can also function as a water absorbing layer for water stopping into the optical cable 1 by applying a water absorbing agent.

  A presser winding coarse winding string 17 is wound around the outer periphery of the vertically wound upper winding tape 16 to prevent the upper winding tape 16 from being unwound. Thereafter, a sheath 18 is extruded and the upper winding tape 16 is wound. It is fixed. However, the sheath 18 may be directly extruded on the outer periphery of the upper winding tape 16 without providing the rough winding string 17.

  The optical cable 2 illustrated in FIG. 1B includes a cable core 21 having a plurality of optical fiber core wires 22 and an upper winding tape 26 wound vertically around the outer periphery of the cable core 21. The cable core 21 bundles a plurality of optical fiber core wires 22 in a bundle shape with a tape or the like to form an optical fiber wire bundle 23. A plurality of the optical fiber wire bundles 23 are assembled and twisted together with a buffer material 25 bundled with yarn or the like. The outer shape is circular. The upper winding tape 26 is the same as the upper winding tape 16, and is formed with overlapping portions (the upper layer side overlapping portion 26a and the lower layer side overlapping portion 26b) so that one end face 26c is on the upper side.

  Then, like the optical cable 1, a sheath 28 is extruded on the outer periphery of the vertically wound upper tape 26 after the coarsely wound string 27 is wound, and the winding of the upper tape 26 is fixed. However, the tension member 24 is embedded in the sheath 28.

  Next, an example of the optical cable and the manufacturing method thereof according to the present embodiment will be described with reference to FIG. FIG. 2 is a diagram illustrating an example of a production line (optical cable production apparatus) of the optical cable 1 in FIG. 1A. Note that the description of the production of the slotless optical cable 2 is omitted because the main features of the present embodiment are the same.

  The production line illustrated in FIG. 2 includes a slot feeder 31, a feeding capstan 32, an optical fiber supply bobbin 33, a wire concentrator 34, a rough winding device 35, a vertical attachment device (forming device) 40, a tear string supply bobbin 36, a rough A winding device 37, a take-up capstan 38, and a winder 39 are provided.

  On the most upstream side (the leftmost side in FIG. 2) of the production line, there is provided a slot feeder 31 that feeds out the SZ-type slot rod 13 wound around the drum and supplies it to the production line. In the center of the production line, a concentrator 34 made of a collecting die or the like is provided. The concentrator 34 fixes the phase of the groove 13a of the slot rod 13 so that the predetermined groove 13a always passes through a certain position. A winder 39 is provided on the most downstream side (the rightmost side in FIG. 2) of the production line to wind up the slot rod 13 wound up.

  The slot rod 13 fed out from the slot feeder 31 passes through the feeding capstan 32 and goes to the concentrator 34. A fixed tension is applied to the slot rod 13 by the feeding capstan 32 and the take-up capstan 38 on the downstream side of the concentrator 34 so that the concentrator 34 is passed.

  On the upstream side of the concentrator 34, optical fiber supply bobbins 33 for supplying the optical fiber core 12 to the concentrator 34 are provided according to the number of optical fiber cores 12 accommodated in the grooves 13a. The optical fiber core wire 12 supplied by the optical fiber supply bobbin 33 is accommodated in the groove 13 a of the slot rod 13 by the concentrator 34.

  Here, the concentrator 34 includes a groove position fixing guide for setting the position of the groove 13a of the slot rod 13 to a fixed position. The groove position fixing guide keeps the position of the predetermined groove 13a of the slot rod 13 passing therethrough at a constant position in the circumferential direction, and the protrusion provided on the groove position fixing guide is inserted into the groove 13a. The passage position is restricted to the groove 13a. Since the grooves 13a of the SZ-type slot rod 13 have spiral shapes that are alternately reversed, the circumferential position of the groove 13a is fixed, so that the slot rods 13 before and after the groove position fixing guide are twisted. And twisted. This twist amount (twist angle) becomes maximum at the reversal portion of the groove 13a.

  A coarse winding device 35 is provided on the downstream side of the concentrator 34. The coarse winding device 35 includes a coarse winding string supply bobbin around which one or a plurality of coarse winding strings 15 are wound, and the coarse winding string 15 is supplied from the coarse winding string 15 to the slot rod 13 in which the optical fiber core wire 12 is accommodated. The cable core 11 is wound horizontally on the outer periphery. Thereby, the optical fiber core wire 12 is held inside the groove 13a. In addition, the intermediate product after giving the rough winding string 15 can also be called the cable core 11.

  The cable core 11 around which the coarsely wound string 15 is wound is inserted into a longitudinal attachment device 40 provided on the downstream side of the coarse winding device 35 and subjected to longitudinal attachment by the upper winding tape 16. The vertical attachment device 40 of the production line according to this embodiment is provided with an upper winding tape supply bobbin 41 around which the upper winding tape 16 is wound, a plurality of rollers such as a roller 42, and a former 43. In the present embodiment, the upper tape 16 wound around the upper tape supply bobbin 41 has a main feature. This feature will be described later.

  The former 43 is a forming member having a tapered insertion opening, and has a cylindrical shape except for the tapered portion. In the outer periphery of the cable core 11, the former 43 forms the upper winding tape 16 in a cylindrical shape so as to form overlapping portions (the upper layer side overlapping portion 16 a and the lower layer side overlapping portion 16 b) at both end portions in the width direction of the upper winding tape 16. It is a member to be wound.

  The former 43 may be formed by rolling a sheet of high density polyethylene (HDPE) having a width larger than the width of the upper winding tape 16, for example. If the former 43 is too hard (for example, a metal material such as an aluminum plate), it takes a long time to adjust the outer shape of the slot rod 13 in accordance with the outer shape of the slot rod 13, leading to an increase in setup time. On the other hand, if the former 43 is too soft, tightening is insufficient, and wrinkles are generated or the former 43 is easily worn and easily broken. Therefore, by adopting a sheet made of HDPE and making the hardness of the former 43 moderate, it is easy to make adjustments according to the outer shape, and troubles such as breakage and the like can be added stably and vertically. Further, the former 43 may be tapered over the entire length as shown in FIG. 2, but the downstream side may be rounded into a cylindrical shape, and the upstream side may be rounded into a tapered shape.

  After such vertical attachment (winding step), the tear string supply bobbin 36 supplies a tear string not shown in FIG. The tear string is a string for tearing the sheath 18 when the optical cable 1 is disassembled. The coarse winding device 37 has a coarse winding string supply bobbin around which one or a plurality of coarse winding strings 17 are wound, and the coarse winding string 17 is supplied from the rough winding string 17 to the outer periphery of the upper winding tape 16 (the outer periphery of the tear string). I will roll it sideways.

  The cable core 11 after the coarsely wound string 17 is wound in this way is taken up by the take-up capstan 38 and taken up by the winder 39. The feed capstan 32 and the take-up capstan 38 are each composed of a plurality of wheels, and send out the wound slot rod 13 while holding it without rotating it in the circumferential direction. Thereby, the twist of the slot rod 13 generated on one side of the feeding capstan 32 and the take-up capstan 38 is not transmitted to the other side.

  The product taken up by the winder 39 is then fed out again, and the outer periphery thereof is covered with the sheath 18 by an extrusion molding device (not shown), cooled by a cooling device (not shown), and finished product. The optical cable 1 becomes. However, in the production line of FIG. 2, an extrusion molding device and a cooling device may be provided in front of the take-up capstan 38 so that the coating process with the sheath 18 may be performed on the same production line.

  In the optical cable manufacturing method according to the present embodiment, the optical cable 1 is manufactured as described above. Prior to that, the length of the upper tape 16 is increased and then wound on the upper tape supply bobbin 41. It is necessary to connect the upper winding tapes 16 when lengthening, and the connection method will be described with reference to FIGS. 3A to 3C. FIG. 3A is a cross-sectional view in the thickness direction showing the state of the connection portion of the upper tape connected by the connection method according to the present embodiment, and FIG. 3B is a thickness direction showing the state in which the connection portion in FIG. 3A is actually connected. Sectional drawing and FIG. 3C are top views which show the connection part of the upper winding tape of FIG. 3B.

  The upper winding tape 16 wound around the upper winding tape supply bobbin 41 has a connecting portion (joining portion) 16j that is melt-bonded by overlapping the end portions in the longitudinal direction as illustrated in FIGS. 3B and 3C. Yes. Here, the ends refer to ends of two upper-winding tapes (referred to as upper-winding tape materials 16p and 16q for distinguishing from the upper-winding tape 16 wound around the upper-winding tape supply bobbin 41).

  At least one connecting portion 16j exists in one upper tape supply bobbin 41. Each time the length of the tape is increased, the number of upper tape materials to be used increases and the number of connection portions 16j also increases. For example, the upper tape 16 is wound around the upper tape supply bobbin 41 after elongating, for example, 10 rolls of a 1 km material to a length of 10 km. Further, the end portions may be overlapped with each other with a predetermined length.

  And since such a connection part 16j is performing the fusion | melting joining by the tape of the same quality without using an adhesive agent, there is no change of hardness like the past, and it can prevent the former 43 from being caught, In addition, it is possible to maintain a stable strength without being affected by outside air temperature and aging deterioration, and to perform operation management without considering the temperature management of the connection portion 16j and the expiration date. Further, since the connection portion 16j is a fusion connection, its actual thickness H can be made about 30% thinner than the overlapped thickness of the upper tape materials 16p and 16q. it can. Thus, according to this embodiment, the longitudinal connection between the upper winding tapes can be strengthened.

  As described above, the optical cable manufacturing method according to the present embodiment includes a joining process, a winding process, and a winding process. As described above, the joining step is a step of configuring the upper winding tape 16 by superposing and melting and joining the longitudinal ends of a plurality of upper winding tape materials (for example, the upper winding tape materials 16p and 16q). . The winding step is a step of winding the upper winding tape 16 on a reel after the joining step. This reel is mounted on the production line as the upper tape supply bobbin 41. The winding step is a step of winding the upper winding tape 16 around the outer periphery of the cable core 11 while feeding the upper winding tape 16 from the upper winding tape supply bobbin 41. When the upper tape 16 is lost, the upper tape supply bobbin 41 may be replaced, and the upper tapes 16 may be melt-bonded in the above-described bonding step.

  Moreover, it is preferable that the said fusion | melting joining is a fusion | melting joining by an ultrasonic wave so that it may illustrate in FIG. 3A. In this case, for example, as described in Patent Document 2, welding is performed by pressing the pressing surface of the horn 50 using an ultrasonic welding apparatus that emits ultrasonic waves from the horn 50 having the pressing surface having the convex portions 51 locally. do it. A circular recess as shown in FIG. 3C is formed in the connection portion 16j corresponding to the projection 51, and the upper winding tape materials 16p and 16q are bonded to the recess. In addition, the arrow in FIG. 3C points out the advancing direction of the upper winding tape in a production line.

  Further, not limited to ultrasonic waves, for example, melt bonding can be performed by locally heating (for example, only a concave portion) with heat. The local heating may be performed, for example, by using a heating head having a pressing surface having a convex portion locally and heating the pressing surface while pressing it. In particular, thermal bonding is also effective for the upper tape 16 made of polyester.

  Moreover, as illustrated in FIG. 3C, it is preferable that the connection portion 16j is locally melt-bonded at a plurality of locations in a region where the end portions are overlapped. As a result, it is possible to melt and bond easily and firmly as compared with melting at only one place.

  The connecting portion 16j preferably has a length in the longitudinal direction of the upper winding tape 16 of 10 mm or less and a tensile breaking strength at a tensile speed of 20 mm / min of 120 N / 30 mm or more.

  In this way, by suppressing the length of the connecting portion 16j to 10 mm or less, the repulsive force to open the overlap is further reduced, the catch of the former 43 is further prevented, the vertical attachment is made easier, and the breakage is further broken. It becomes possible to make it difficult. In addition, by setting the tensile breaking strength to 120 N / 30 mm or more, it is possible to avoid a breaking trouble at the connection portion 16j even when the production speed is maintained to some extent. That is, by forming the connecting portion 16j to be as short as possible and to have a tensile breaking strength so as to satisfy these conditions, it is possible to make the melt connection more firmly and increase the production speed. Actually, it was manufactured using the upper winding tape connected under these conditions, but it was possible to melt and connect more firmly and increase the manufacturing speed.

  In the above, only the example in which the upper tape 16 is vertically attached has been described, but it can also be applied to horizontal winding. However, in the horizontal winding structure, for example, the upper winding tape supply bobbin 41 needs to be rotated around the cable core 11. Therefore, the length of the upper winding tape 16 that can be set on the production line is shorter than that of the vertical attachment structure. That is, the longitudinally attached structure allows the length of the upper winding tape to be longer than that of the horizontal winding structure (the upper tape supply bobbin 41 having a larger number of connecting portions can be used). Therefore, it can be said that the effect of the present embodiment is more remarkable in the vertically attached structure than in the horizontally wound structure.

  Moreover, the connection method of the upper winding tape in this embodiment can be utilized as a connection method of the upper winding tape in an electric wire cable.

  As described above, the embodiments disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is not limited to the examples described above, but is defined by the claims, and is intended to include all modifications within the scope and meaning equivalent to the claims.

DESCRIPTION OF SYMBOLS 1, 2 ... Optical cable 11, 21 ... Cable core, 12, 22 ... Optical fiber core wire, 13 ... Slot rod, 13a ... Groove, 14, 24 ... Tension member, 15, 17, 27 ... Coarse winding string, 16, 26 ... upper winding tape, 16a, 26a ... upper layer side overlapping portion, 16b, 26b ... lower layer side overlapping portion, 16c, 26c ... end face, 16j ... connection portion, 16p, 16q ... upper winding tape material, 18, 28 ... sheath, DESCRIPTION OF SYMBOLS 23 ... Optical fiber wire bundle, 25 ... Buffer material, 31 ... Slot feeder, 32 ... Feeding capstan, 33 ... Optical fiber supply bobbin, 34 ... Concentrator, 35, 37 ... Coarse winding device, 36 ... Tear string supply bobbin, 38 ... Winding capstan, 39 ... Winding machine, 40 ... Vertical attachment device (forming device), 41 ... Upper winding tape supply bobbin, 42 ... Roller, 43 ... Four , 50 ... horn, 51 ... protruding portion.

Claims (4)

An optical cable comprising a cable core having a plurality of optical fibers, an upper winding tape wound around the outer periphery of the cable core, and a sheath covering the outer periphery of the upper winding tape,
The upper-winding tape is an optical cable having a connection portion that is melt-bonded by overlapping end portions in the longitudinal direction.   The optical cable according to claim 1, wherein the connection portion is locally melt-bonded at a plurality of locations in a region where the end portions are overlapped with each other.   3. The optical cable according to claim 1, wherein the connecting portion has a length in the longitudinal direction of the upper tape of 10 mm or less and a tensile breaking strength at a tensile speed of 20 mm / min is 120 N / 30 mm or more. An optical cable manufacturing method for manufacturing an optical cable comprising a cable core having a plurality of optical fibers, an upper winding tape wound around the outer periphery of the cable core, and a sheath covering the outer periphery of the upper winding tape,
By joining the longitudinal ends of a plurality of upper-winding tape materials in a melt-bonding manner, a joining step that constitutes the upper-winding tape,
A winding step of winding the upper tape on a reel after the joining step;
A winding step of winding the upper winding tape from the reel while winding the outer periphery of the cable core;
An optical cable manufacturing method comprising:

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