Optical branch cable and optical branch cable set

Abstract

To provide an optical branch cable and an optical branch cable set that have improved ease of manufacture.SOLUTION: An optical branch cable comprises a main cable and a branch cord part. The main cable includes a plurality of optical cords each including at least one coated optical fiber, a tensile strength body, and a tape that forms an outermost layer. In the branch cord part, at least one coated optical fiber is derived to the outside of the outermost layer from the optical cords of the main cable. The optical branch cable includes an optical cord group and a core part. The optical cord group includes the plurality of optical cords bound by a first bundle. The core part includes an optical cord group bound by a second bundle and the tensile force body. The tape is wound around the core part by longitudinal lapping, and covers the core part.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to an optical branching cable and an optical branching cable set. [Background technology]

[0002] Patent Document 1 discloses an optical branching cable that connects a server rack group having multiple server racks to a distribution board. The optical branching cable includes a main cable and branch cords that branch off from the main cable and are connected to each server rack. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2023-083096 Summary of the Invention [Problem to be solved by the invention]

[0004] The layout of server racks in a server rack cluster varies depending on the application. For this reason, optical branching cables are manufactured so that the locations of the branching sections where the main cable and branch cord branch off correspond to the layout of each server rack. Branching cables that are easy to manufacture not only reduce the labor required for manufacturing, but are also beneficial in that they can be easily adapted to various server rack clusters.

[0005] An object of the present disclosure is to provide an optical branching cable and an optical branching cable set that are easier to manufacture. [Means for solving the problem]

[0006] An optical branching cable according to one embodiment of the present disclosure is an optical branching cable comprising: a main cable comprising a plurality of optical cords, each comprising at least one optical fiber core, a tensile strength member, and a tape forming the outermost layer; and a branching cord portion in which at least one optical fiber core is led out from the optical cords of the main cable outside the outermost layer, the optical branching cable comprising: an optical cord group including the plurality of optical cords bundled together in a first bundle; and a core portion including the optical cord group bundled together in a second bundle and the tensile strength member, and the tape is wrapped longitudinally around the core portion, covering the core portion. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to improve the ease of manufacturing optical branching cables and optical branching cable sets. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 illustrates an optical communication system according to this embodiment. [Figure 2] FIG. 2 is a schematic diagram of an optical branch cable. [Figure 3] FIG. 3 is a cross-sectional view of the main cable. [Figure 4] FIG. 4 is a partial enlarged view of the tape. [Figure 5] FIG. 5 illustrates a branch cord bag. [Figure 6] FIG. 6 is a cross-sectional view taken along the line VI-VI in FIG. [Figure 7] FIG. 7 is a perspective view of the bending restricting component. [Figure 8] FIG. 8 illustrates an example of a bend restricting part and a branch cord portion. [Figure 9] FIG. 9 illustrates the installation of an optical branch cable using a pulling jig. [Figure 10] FIG. 10 is a plan view of the traction jig. [Figure 11] FIG. 11 is a cross-sectional view taken along the line XI-XI in FIG. [Figure 12] FIG. 12 illustrates the fixed position of the connection. [Figure 13] FIG. 13 is a view of the optical branch cable as seen from a direction intersecting the width direction. [Figure 14] FIG. 14 illustrates an example of an optical branch cable aligned by a pulling jig. [Figure 15] FIG. 15 is a perspective view of an optical branch cable set according to a modified example. [Figure 16] FIG. 16 illustrates an optical branching cable set and a branching cord bag according to a modified example. [Figure 17] FIG. 17 illustrates an example of the arrangement of the branch cord portions of each optical branch cable. DETAILED DESCRIPTION OF THE INVENTION

[0009] (Description of Embodiments of the Present Disclosure) First, embodiments of the present disclosure will be listed and described. (1) An optical branching cable according to one embodiment of the present disclosure is an optical branching cable comprising: a main cable including a plurality of optical cords, each including at least one optical fiber core, a tensile strength member, and a tape forming an outermost layer; and a branching cord portion in which at least one optical fiber core is led out from the optical cords of the main cable outside the outermost layer, the optical branching cable comprising: an optical cord group including the plurality of optical cords bundled together in a first bundle; and a core portion including the optical cord group bundled together in a second bundle and the tensile strength member, and the tape is wrapped longitudinally around the core portion to cover the core portion.

[0010] According to the above-described optical branch cable, the optical cord group is bundled by the first bundle so as to be separate from the tension members, making it easy to distinguish between the optical cord group and the tension members during work. This allows for the task of branching optical fiber cores from the optical cord group to create a branch cord portion. The outermost layer is wrapped vertically to cover the core portion, so the optical cord group is not embedded in the resin coating layer. This allows for partial peeling starting from the overlapping portion of the vertically wrapped tape, exposing the optical cords to the outside. This facilitates the task of branching optical fiber cores from the main cable to create a branch cord portion. Compared to a case where the outermost layer is resin-coated by extrusion molding, this eliminates the need to remove the extruded coating when extracting the branch cord portion, thereby reducing the number of steps required for manufacturing the optical branch cable and improving the ease of manufacturing the optical branch cable.

[0011] (2) In the optical branching cable according to (1) above, a slit may be formed in the tape at a position corresponding to a branching portion that leads out the branching cord portion from the main cable, the slit extending along the circumferential direction of the main cable in a part of the circumferential direction of the tape, and the branching cord portion may be led out from the main cable through the slit.

[0012] With the optical branch cable described above, the tape can be partially peeled off using the slit to expose the optical cord to the outside. This makes it easy to fabricate the branch cord portion. Furthermore, because the branch cord portion branches off from the main cable through the slit, the area of ​​the main cable exposed after fabricating the branch cord portion can be reduced.

[0013] (3) In the optical branching cable according to (2) above, the slit may be formed in the overlapping portion of the longitudinally wrapped tape, from the circumferential end of the inner layer portion to the circumferential end of the outer layer portion.

[0014] According to the above optical branching cable, the circumferential ends of the inner layer portion and the outer layer portion are removed by slits, so that the tape can be easily partially peeled off from the circumferential ends of the tape using the slits.

[0015] (4) In the optical branching cable according to any one of (1) to (3) above, an optical connector may be provided at the tip of the branching cord portion, and a branching cord bag may be provided in which at least a portion of the branching cord portion can be stored in a coiled state.

[0016] According to the above-mentioned optical branching cable, at least a portion of the branching cord portion is stored in a branching cord bag in a coiled state, so that the branching cord portion can be protected in a state that makes it easy to remove after manufacture.

[0017] (5) In the optical branch cable according to (4) above, at least one surface of the branch cord bag may be semicircular.

[0018] According to the above optical branch cable, at least one surface of the branch cord bag is semicircular, so that the branch cord bag can be easily stored in a state where it fits into the branch cord portion in a coiled state.

[0019] (6) In the optical branch cable according to (4) or (5) above, the inner surface of the branch cord bag and the main cable may be connected by a hook-and-loop fastener.

[0020] In the optical branch cable described above, the branch cord bag and the main cable are bonded together with a hook-and-loop fastener, which makes it difficult for the branch cord bag to shift relative to the main cable, and therefore the branch cord portion is less likely to lose its shape when wound in a coil.

[0021] (7) In the optical branching cable according to any one of (4) to (6) above, a bend restricting part may be attached at a position corresponding to the branching part leading out the branching cord part from the main cable, the bend restricting part including an attachment part that can be attached to the main cable, a bend restricting part that restricts the branching cord from bending at a radius less than a predetermined bend radius, and a main body part that is formed along the outer shape of the main cable and that, together with the bend restricting part, defines a connector passage part that is a hole through which the optical connector can pass.

[0022] According to the above optical branching cable, the branching cord portion is restricted by the bend restricting portion so as not to bend at a radius less than a predetermined bending radius, thereby preventing the branching cord portion from being damaged by unintentional small-diameter bending.

[0023] (8) An optical branching cable set according to one embodiment of the present disclosure is an optical branching cable set in which optical branching cables according to any one of (1) to (7) above are arranged in parallel in a direction intersecting the longitudinal direction, and the optical branching cables are provided with a branching cord bag that can store at least a portion of the branching cord portion in a coiled state, and an outer surface of each of the branching cord bags is formed with an outer fastener portion, and the branching cord bags of adjacent optical branching cables are connected to each other by the outer fastener portion.

[0024] According to the optical branching cable set, when the optical branching cables are arranged in parallel, the branching cord bags of adjacent optical branching cables are adhered to each other by the outer surface fasteners, so that the plurality of optical branching cables can move together. According to the present disclosure, it is easy to manufacture an optical branching cable set for laying in parallel at one time.

[0025] (9) In the optical branch cable set according to (8) above, the outer surface fastener portion may be formed so as to extend in the longitudinal direction.

[0026] With the optical branch cable set described above, the longitudinal position of the optical branch cable where the branch cord portion is formed may be misaligned depending on the optical branch cable due to manufacturing errors, etc. Since the outer surface fastener portion is formed to extend in the longitudinal direction, the branch cord bags can be easily bonded together even if the longitudinal position of the optical branch cable where the branch cord portion is formed is misaligned.

[0027] (Details of the embodiments of the present disclosure) Specific examples of optical branching cables and optical branching cable sets according to embodiments of the present disclosure will be described below with reference to the drawings. Note that the present disclosure is not limited to these examples, but is defined by the claims, and is intended to include all modifications within the meaning and scope of the claims.

[0028] (optical branching cable) FIG. 1 illustrates an optical communication system 100 according to this embodiment. As illustrated in FIG. 1, the optical communication system 100 includes a distribution board 110 and a plurality of server racks 120. Optical branching cables 1 used in the optical communication system 100 are concentrated and connected to the distribution board 110. The server racks 120 house physical servers therein. Optical fibers branched from the optical branching cable 1 are connected to each server rack 120. The optical branching cables 1 are laid in a cable laying tray T and wired to the distribution board 110 and the server racks 120.

[0029] Fig. 2 is a schematic diagram of the optical branch cable 1. As illustrated in Fig. 2, the optical branch cable 1 includes a main cable 10, a branch cord section 20, a branch cord bag 30, a bend restricting member 40, a tip bag 50, and a connection loop 60.

[0030] 3 is a cross-sectional view of the main cable 10. The main cable 10 includes a plurality of optical cords 11, a strength member 12, and a tape 13. The optical cords 11, the strength member 12, and the tape 13 are arranged along the longitudinal direction of the main cable 10.

[0031] Each of the optical cords 11 includes at least one optical fiber 11A therein. In this embodiment, the optical cord 11 includes 24 optical fiber 11A therein. The optical cords 11 are bundled together in a first bundle 14 to form an optical cord group 15.

[0032] The tension members 12 are formed of fiber reinforced plastic (FRP), such as aramid FRP, glass FRP, or carbon FRP. The tension members 12 are configured so that tension is applied when the optical branching cable 1 is pulled. The optical cord group 15 and the tension members 12 are bound together by a second bundle 16 to form a core portion 17.

[0033] The tape 13 forms the outermost layer of the main cable 10. The tape 13 is wound longitudinally around the core 17 to maintain a shape that covers the core 17. The tape 13 is a sheet-like insulating resin, and may be made of, for example, polyester.

[0034] Returning to Fig. 2, the branch cord section 20 is a cord in which at least one optical fiber 11A is led out from the optical cord 11 of the main cable 10 to the outside of the tape 13, which is the outermost layer. An optical connector 21 is provided at the tip of the branch cord section 20. The branch cord section 20 may be one in which the optical fiber 11A in the optical cord 11 is led out beyond the outermost layer of the main cable 10, or one in which the optical cord 11 itself is led out beyond the outermost layer of the main cable 10.

[0035] Fig. 4 is a partially enlarged view of the tape 13. As illustrated in Fig. 4, the tape 13 is longitudinally wrapped around the core portion 17 to form an overlapping portion where the tape 13 overlaps twice. In the overlapping portion, the circumferential end of the inner layer portion of the tape 13 is designated as a first end portion 13A, and the circumferential end of the outer layer portion of the tape 13 is designated as a second end portion 13B.

[0036] A slit S is formed in the tape 13 at a position corresponding to the branching portion where the main cable 10 branches off to the branch cord portion 20. The slit S is formed in a part of the circumferential direction of the tape 13 so as to extend along the circumferential direction of the main cable 10.

[0037] The slit S is formed so as to penetrate the inner layer and the outer layer of the overlapping portion. The slit S is formed from the first end 13A to the second end 13B of the overlapping portion of the longitudinally wrapped tape 13. In other words, the slit S is formed so as to include the first end 13A and the second end 13B.

[0038] The branch cord portion 20 is led out from the main cable 10 through the slit S. In Figure 4, the arrows show how the branch cord portion 20 passes through the slit S. The dashed lines indicate that the branch cord portion 20 passes inside the tape 13, which is the outermost layer of the main cable 10.

[0039] As illustrated in Fig. 4, before branching from the main cable 10, the branch cord portion 20 passes inside the outermost layer formed by the tape 13. The branch cord portion 20 is led out from the main cable 10 by passing through a slit S. As a result, the branch cord portion 20 is positioned outside the outermost layer.

[0040] (branch cord bag) 5 illustrates the branch cord bag 30. In addition, the outline of the branch cord bag 30 is indicated by a broken line in FIG. 5. FIG. 6 is a cross-sectional view taken along line VI-VI in FIG.

[0041] The branch cord bag 30 is configured to be able to store the branch cord section 20. When the branch cord section 20 does not need to be connected to the server rack 120 (see FIG. 1), such as during transportation, it is stored in the branch cord bag 30. The branch cord bag 30 is configured to be able to store the branch cord section 20 with at least a portion of the branch cord section 20 wound in a coil shape.

[0042] The branch cord bag 30 has a flat shape, and a portion thereof is formed so as to be openable. At least one surface of the branch cord bag 30 may be semicircular. In the present embodiment, the outer surface of the branch cord bag 30 may have two main surfaces 31. The main surfaces 31 are the surfaces of the branch cord bag 30 with the largest area. The main surfaces 31 of the branch cord bag 30 may be semicircular so as to fit along the branch cord portion 20 wound in a coil shape.

[0043] 6, a first hook-and-loop fastener portion 32a and a second hook-and-loop fastener portion 32b are formed on the inner surface of the branch cord bag 30. The first hook-and-loop fastener portion 32a and the second hook-and-loop fastener portion 32b are formed at a position on the main surface 31 that forms an opening of the branch cord bag 30, with their connecting surfaces facing the main cable 10. In this embodiment, the first hook-and-loop fastener portion 32a and the second hook-and-loop fastener portion 32b form hook surfaces of the hook-and-loop fasteners.

[0044] A cable hook-and-loop fastener portion 18 is formed on the outer surface of the main cable 10. The cable hook-and-loop fastener portion 18 may be provided only at a position corresponding to the branch portion. In this embodiment, the cable hook-and-loop fastener portion 18 forms a loop surface.

[0045] The first hook-and-loop fastener portion 32a and the second hook-and-loop fastener portion 32b are configured to be connectable to the cable hook-and-loop fastener portion 18. In other words, the inner surface of the branch cord bag 30 and the main cable 10 are connected by the first hook-and-loop fastener portion 32a, the second hook-and-loop fastener portion 32b, and the cable hook-and-loop fastener portion 18. In this embodiment, the third hook-and-loop fastener portion 32c forms the hook surface of the hook-and-loop fastener.

[0046] 6, a third hook-and-loop fastener portion 32c is formed on the inner surface of the branch cord bag 30. The third hook-and-loop fastener portion 32c is formed to protrude in the direction of the opening of the branch cord bag 30.

[0047] A fourth hook-and-loop fastener portion 32d is formed on the outer surface of the main surface 31 on which the second hook-and-loop fastener portion 32b is provided in the branch cord bag 30. In this embodiment, the fourth hook-and-loop fastener portion 32d forms a loop surface.

[0048] The third hook-and-loop fastener portion 32c is configured to be able to connect to the fourth hook-and-loop fastener portion 32d. As illustrated in Fig. 6, by performing a connecting operation O1 such that the portion where the third hook-and-loop fastener portion 32c is provided is folded onto the fourth hook-and-loop fastener portion 32d, the third hook-and-loop fastener portion 32c is connected to the fourth hook-and-loop fastener portion 32d. This makes it possible to close the opening of the branch cord bag 30. The branch cord bag 30 is arranged so as to wrap around the main cable 10, which further strengthens the connection between the branch cord bag 30 and the main cable 10.

[0049] A fifth hook-and-loop fastener portion 32e is formed on the outer surface of the main surface 31 on which the first hook-and-loop fastener portion 32a is provided in the branch cord bag 30. In this embodiment, the fifth hook-and-loop fastener portion 32e forms a loop surface.

[0050] A sixth surface fastener portion 32f is formed on the outer surface of the main surface 31 on which the second surface fastener portion 32b is provided in the branch cord bag 30. In this embodiment, the sixth surface fastener portion 32f forms a loop surface.

[0051] The fifth hook-and-loop fastener portion 32e is configured to be connectable to the sixth hook-and-loop fastener portion 32f of a different branch cord bag 30 (see FIG. 13). The fifth hook-and-loop fastener portion 32e and the sixth hook-and-loop fastener portion 32f may be formed to extend along the longitudinal direction of the main cable 10 (see FIG. 14). The fifth hook-and-loop fastener portion 32e and the sixth hook-and-loop fastener portion 32f are examples of outer hook-and-loop fastener portions.

[0052] (Bending restriction parts) 2 and 5, a bend restricting part 40 is attached to a position corresponding to the branch portion of the optical branch cable 1. Fig. 7 is a perspective view of the bend restricting part 40. Fig. 8 illustrates the bend restricting part 40 and the branch cord portion 20.

[0053] As illustrated in FIG. 7, the bend restricting component 40 includes an attachment portion 41, a bend restricting portion 42, and a main body portion 43.

[0054] The attachment portions 41 are configured to be attachable to the main cable 10. In this embodiment, the bend restricting part 40 is provided with four attachment portions 41. The bend restricting part 40 is attached to the main cable 10 by clamping the main cable 10 between the four attachment portions 41.

[0055] The main body 43 is formed in a curved shape so as to fit the outer shape of the main cable 10. Therefore, the main body 43 has a partial cylindrical shape.

[0056] The bend restricting portion 42 is provided so as to protrude from the main body portion 43 in a direction intersecting the axial direction of the main cable 10 when the bend restricting part 40 is attached to the main cable 10. The boundary portion between the bend restricting portion 42 and the main body portion 43 is formed into a rounded curved surface so as to ensure a bend radius equal to or larger than a predetermined bend radius.

[0057] The bend restricting portion 42 restricts the position of the branch cord portion 20 so that the branch cord portion 20 is not bent at a radius less than a predetermined bend radius. As illustrated in FIG. 8 , the branch cord portion 20 is led out from the main cable 10 along the boundary between the bend restricting portion 42 and the main body portion 43.

[0058] The main body 43, together with the bend restricting part 42, defines a connector passing part 44, which is a hole through which the optical connector 21 can pass. When the bend restricting part 40 is attached to the main cable 10, the optical connector 21 and the branch cord part 20 are passed through the connector passing part 44 and are housed together with the bend restricting part 40 in the branch cord bag 30.

[0059] As shown in FIG. 2, the tip bag 50 is provided to protect the end of the optical cord 11 exposed at the tip of the main cable 10 and the end optical connector C provided at the end of the optical cord 11.

[0060] The connecting loop 60 is connected to the tension member 12 exposed at the tip of the main cable 10. The connecting loop 60 is a portion that is connected to a traction device such as a winch. The connecting loop 60 is formed in a ring shape, and when the connecting loop 60 is pulled, tension is applied to the tension member 12, causing the optical branch cable 1 to be displaced.

[0061] Next, a manufacturing process for leading out the branch cord portion 20 from the main cable 10 will be described.

[0062] In order to lead the branch cord portion 20 out of the main cable 10, it is necessary to expose the optical cord 11 to the outside. In this embodiment, the optical cord 11 can be easily exposed to the outside by partially peeling off the tape 13, which is wrapped vertically, starting from the overlapping portion of the tape 13. In particular, when a slit S is formed in the tape 13, the tape 13 can be easily peeled off using the slit S.

[0063] 4, in particular, when the slit S is formed from the first end 13A, which is the circumferential end of the inner layer portion, to the second end 13B, which is the circumferential end of the outer layer portion, as in this embodiment, it is easy to expose the optical code 11 to the outside. Starting from the second end 13B, the tape 13 is partially peeled off so that the first end 13A is exposed to the outside, and once the first end 13A is exposed to the outside, the tape 13 is partially peeled off starting from the first end 13A, thereby easily exposing the optical code 11 to the outside.

[0064] In optical branching cables, when the outermost layer is formed by extrusion molding with a resin coating, the extruded coating must be removed in order to lead out the branch cord portion from the main cable. In this case, all of the coating in the circumferential direction of the main cable must be removed in a portion of the cable's longitudinal direction, and the time and effort required for removing the coating is one of the reasons for the increase in the number of steps required to manufacture optical branching cables.

[0065] According to the optical branch cable 1 of this embodiment, the optical cord group 15 is bundled by the first bundle 14 so as to be separate from the tension members 12, and therefore, it is easy to work while distinguishing between the optical cord group 15 and the tension members 12. This makes it possible to branch the optical fiber core 11A from the optical cord group 15 and fabricate the branch cord portion 20. The outermost tape 13 is wrapped vertically to cover the core portion 17. Therefore, the tape 13 can be partially peeled off starting from the overlapping portion of the vertically wrapped tape 13, exposing the optical cord 11 to the outside. This makes it possible to branch the optical fiber 11A from the main cable 10 and produce the branch cord portion 20. Compared to when the outermost layer is coated with a resin by extrusion molding, there is no need to remove the extruded coating when extracting the branch cord portion 20. This reduces the number of steps required to manufacture the optical branch cable 1, and makes it easier to manufacture the optical branch cable 1.

[0066] In the optical branch cable 1 according to this embodiment, the tape 13 can be partially peeled off using the slit S to expose the optical cord 11 to the outside. This facilitates the work of fabricating the branch cord section 20. Furthermore, because the branch cord section 20 branches off from the main cable 10 through the slit S, the exposed area of ​​the main cable 10 can be reduced after the work of fabricating the branch cord section 20.

[0067] In the optical branching cable 1 of this embodiment, the first end 13A, which is the circumferential end of the inner layer portion, and the second end 13B, which is the circumferential end of the outer layer portion, are removed by the slit S, so that the slit S can be used to easily peel off the tape 13 partially from its circumferential end.

[0068] In the optical branching cable 1 of this embodiment, at least a portion of the branching cord section 20 is stored in the branching cord bag 30 in a coiled state, so that the branching cord section 20 can be protected in a state that makes it easy to remove after manufacturing.

[0069] In the optical branch cable 1 according to this embodiment, the main surface 31 of the branch cord bag 30 has a semicircular shape, so that it can be easily stored in a state where it fits into the branch cord section 20 in a coiled state.

[0070] In the optical branch cable 1 according to this embodiment, the branch cord bag 30 and the main cable 10 are connected by the cable hook-and-loop fastener portion 18, the first hook-and-loop fastener portion 32a, and the second hook-and-loop fastener portion 32b. This makes it difficult for the branch cord bag 30 to displace relative to the main cable 10, and therefore the branch cord portion 20 is less likely to lose its shape when wound in a coil.

[0071] In the optical branching cable 1 of this embodiment, the branching cord portion 20 is restricted by the bending restriction portion 42 to prevent bending at a radius less than a predetermined bending radius, thereby preventing the branching cord portion 20 from being damaged by unintentional small-diameter bending.

[0072] The optical cord group 15 is bundled by the first bundle 14 so as to be separate from the strength members 12. This prevents the strength members 12 from becoming tangled around the optical cords 11 during the manufacturing process, installation work, etc. If the strength members 12 become tangled around the optical cords 11, the tension when pulled during installation may be applied not only to the strength members 12 but also to the optical cords 11. If tension is applied to the optical cords 11, the optical cords 11 may be damaged. In this embodiment, the first bundle 14 prevents the strength members 12 from becoming tangled around the optical cords 11, thereby preventing damage to the optical cords 11 during installation work.

[0073] Furthermore, the second bundle 16 bundles the optical cord group 15 and the strength members 12. This makes it possible to prevent the relative positional relationship between the optical cord group 15 and the strength members 12 from varying depending on the position in the longitudinal direction of the main cable 10. If the relative positional relationship between the optical cord group 15 and the strength members 12 in the longitudinal direction of the main cable 10 is spiral, the tension applied to the strength members 12 during installation may also be applied to the optical cord group 15. In this embodiment, the relative positional relationship between the optical cord group 15 and the strength members 12 can be prevented from varying depending on the position in the longitudinal direction of the main cable 10, thereby preventing damage to the optical cords 11 during installation.

[0074] (Towing jig) Next, a pulling jig 201 for pulling the optical branching cable 1 will be described. Fig. 9 illustrates an example of how the optical branching cable 1 is laid using the pulling jig 201. As illustrated in Fig. 9, multiple optical branching cables 1 are arranged in parallel while being housed in grooves formed in a cable laying tray T. The pulling jig 201 is used to pull the multiple optical branching cables 1 while maintaining the parallel arrangement of the multiple optical branching cables 1. The multiple optical branching cables 1 are an example of an optical cable set. The pulling jig 201 and the optical branching cable set are an example of an optical cable pulling system.

[0075] 10 is a plan view of the pulling jig 201. As illustrated in FIG. 10, the pulling jig 201 includes a base 210, a pulling portion 220, and a plurality of connection portions 230. The base 210 has a width equal to or greater than the width of the plurality of optical branching cables 1 arranged in parallel. The "width equal to or greater than the width of the plurality of optical branching cables 1 arranged in parallel" means a width equal to or greater than the sum of the diameters of the plurality of optical branching cables 1 arranged in parallel. Furthermore, the base 210 may have a width slightly smaller than the width of the groove formed in the cable installation tray T so that the base 210 does not rotate in a top view relative to the cable installation tray T illustrated in FIG. 9 during pulling.

[0076] 10, guide portions are formed in the width direction of the base 210 (left-right direction on the paper) so as to extend in a direction intersecting the width direction. The number of guide portions provided is the same as the number of connection portions 230. In this embodiment, the guide portions are formed as guide slits GS, which are grooves formed in the base 210. The guide slits GS are formed so as to extend in a direction intersecting the width direction.

[0077] The base 210 includes an engaged portion 211, which is a surface that defines the upper surface of the gap space V below the guide slit GS and communicates with the guide slit GS (see FIG. 12). The gap space V is formed along the guide slit GS. The gap space V is formed wider in the width direction than the guide slit GS.

[0078] The towing portion 220 is provided to be connectable to a traction device. In this embodiment, the towing portion 220 is formed as a ring-shaped member so that it can be hung on a traction device.

[0079] The multiple connection parts 230 are provided on the base part 210 and are lined up along the width direction (left-right direction on the paper) of the base part 210. By having the connection loop 60 hooked around the connection parts 230, when the pulling jig 201 is pulled, tension can be applied to the optical branch cable 1 in the pulling direction.

[0080] Fig. 11 is a cross-sectional view taken along the line XI-XI of Fig. 10. The connecting portion 230 includes a positioning portion 231 and a fastener 232.

[0081] The positioning portion 231 includes a shaft portion 231a and an engaging portion 231b. The shaft portion 231a can be inserted into the guide slit GS, and has a male thread formed on at least a portion of its outer surface. The engaging portion 231b is a portion that is connected to the shaft portion 231a. The engaging portion 231b is disposed below the guide slit GS. Even if the positioning portion 231 is displaced upward, the engaging portion 231b abuts against the engaged portion 211, preventing it from being inserted into the guide slit GS.

[0082] A female screw that can be fastened to the shaft portion 231a is formed on the fastener 232. The fastener 232 is disposed on the outer surface of the base portion 210, and is configured so as not to be able to pass through the guide slit GS.

[0083] FIG. 12 illustrates fixed positions of the connection portions 230. The connection portions 230 are displaceable along the guide slits GS. Each connection portion 230 can be fixed to one of at least two different positions in a direction intersecting the width direction. In this embodiment, the connection portions 230 can be fixed to a first position A on each guide slit GS and a second position B that is closer to the traction portion 220 than the first position A. The first position A and the second position B are indicated by dashed frames in FIG. 12.

[0084] 11, the connection part 230 is fixed by fastening the fastener 232 to the shaft part 231a. By rotating the fastener 232 in a direction that closes the fastening between the fastener 232 and the shaft part 231a, the positioning part 231 is displaced upward, and the engaging part 231b comes into contact with the engaged part 211. By clamping the engaged part 211 between the fastener 232 and the shaft part 231a, the connection part 230 is fixed to the base part 210 and cannot be displaced on the guide slit GS.

[0085] The connection part 230 is released from the fixed state by loosening the fastening between the locking device 232 and the shaft part 231a. By rotating the locking device 232 in a direction that loosens the fastening between the locking device 232 and the shaft part 231a, the positioning part 231 is displaced downward, and the engaging part 231b no longer abuts against the engaged part 211. By releasing the clamping of the engaged part 211 by the locking device 232 and the shaft part 231a, the connection part 230 can be displaced from the first position A to the second position B, or from the second position B to the first position A.

[0086] 12, the connection portions 230 can be fixed at different positions along the guide slits GS in a direction intersecting the width direction, thereby making it possible to adjust the position at which the connection loop 60, which is the end of the optical branching cable 1, is connected to the pulling jig 201 for each optical branching cable 1.

[0087] (Optical cable pulling method) Next, a method for pulling an optical cable will be described. The optical branch cable 1 is pulled while maintaining the state in which the plurality of optical branch cables 1 are arranged side by side in the width direction.

[0088] 12, each of the multiple connection parts 230 is connected to one optical branch cable 1. By pulling the pulling jig 201 in this state, it is easy to apply a pulling force of equal magnitude in the same direction to all of the optical branch cables 1 connected to the connection parts 230. This makes it easy for all of the optical branch cables 1 to be displaced by the same amount in the same direction, and it becomes possible to pull the multiple optical branch cables 1 together while keeping them aligned.

[0089] Fig. 13 illustrates an optical branching cable 1 connected to a pulling jig 201. Fig. 13 is a view of the optical branching cable 1 as viewed from a horizontal direction intersecting the width direction. As illustrated in Fig. 13, the fifth hook-and-loop fastener portion 32e formed on the branching cord bag 30 may be coupled to the sixth hook-and-loop fastener portion 32f formed on the branching cord bag 30 of adjacent optical branching cables 1. This couples the branching cord bags 30 together, making it easier to maintain the optical branching cables 1 in an aligned state during the pulling operation of the optical branching cables 1.

[0090] When all optical branching cables are connected to one connection point, they are pulled toward that connection point. As a result, the direction and magnitude of the pulling force that each optical branching cable experiences varies depending on the optical branching cable. In particular, optical branching cables located at the ends are pulled toward the center, which can cause them to ride over or cross over adjacent optical branching cables. This can make it difficult to maintain the parallel state of the optical branching cables.

[0091] The pulling jig 201 and optical cable pulling system according to this embodiment include a plurality of connection parts 230 arranged in the width direction. Each of the connection parts 230 is configured to be connectable to one optical branching cable 1. This allows a plurality of optical branching cables 1 to be pulled while each is connected to a connection part 230. This makes it possible to pull a plurality of optical branching cables 1 together with as uniform a force as possible, improving the workability of laying the optical branching cables 1.

[0092] Furthermore, the optical cable pulling method of this embodiment includes pulling a plurality of optical branching cables 1 while maintaining the parallel arrangement thereof using the pulling jig 201. By using the pulling jig 201, it becomes possible to pull a plurality of optical branching cables 1 simultaneously, thereby improving the workability of laying the optical cable.

[0093] Incidentally, manufacturing errors may occur in the position where the branch section where the branch cord section 20 is led out from the main cable 10 is formed for each optical branch cable 1. Specifically, the distance from the end of the optical branch cable 1 to one branch section may differ between adjacent optical branch cables 1. Furthermore, the distance between the branch sections may differ between adjacent optical branch cables 1. However, even if manufacturing errors exist, the positions of the branch sections need to be aligned to some extent in optical branch cables 1 arranged in parallel.

[0094] Fig. 14 illustrates an example of an optical branching cable 1 aligned by a pulling jig 201. In the example of Fig. 14, the position where the branching cord bag 30 is provided indicates the position of the branching portion in the optical branching cable 1. The branching cord bag closest to the connection loop 60 illustrated in Fig. 14 is referred to as the first branching cord bag 30A, and the branching cord bag that is n-th closest to the connection loop 60 is referred to as the n-th branching cord bag.

[0095] 12 , the connecting portion 230 can be fixed to a first position and a second position that are different from each other along the cable longitudinal direction in each guide portion. At this time, when the connecting portion 230 is connected to an optical branching cable 1 having a relatively short distance from the connecting loop 60 to the first branching cord bag 30A, the connecting portion 230 is fixed to the first position A. When the connecting portion 230 is connected to an optical branching cable 1 having a relatively long distance from the connecting loop 60 to the first branching cord bag 30A, the connecting portion 230 is fixed to the second position B.

[0096] In this way, by positioning each connection portion 230 at the appropriate first position A or second position B in accordance with each optical branching cable 1, the position of the first branching cord bag 30A in each optical branching cable 1 can be aligned to a certain extent, as illustrated in Figure 14.

[0097] Furthermore, the distance between the branch cord bags 30 may differ depending on the optical branch cable 1. Even in such a case, by positioning each connection portion 230 at the first position A or the second position B in accordance with the optical branch cable 1, it is possible to align the positions of the n-th branch cord bags 30N in each optical branch cable 1 to some extent, as exemplified in FIG.

[0098] As described above, in the traction jig 201 according to this embodiment, the connection portion 230 can be fixed at either one of two different positions in the direction intersecting the width direction, that is, a first position A or a second position B. As a result, even if the position of the branching portion is shifted in the direction intersecting the width direction by the optical branching cable 1, the displacement of the connection portion 230 makes it easy to align the position of the branching portion in the direction intersecting the width direction to some extent. Note that it is sufficient for each connection portion 230 to be fixable at two different positions in the direction intersecting the width direction, and the fixing positions in the direction intersecting the width direction of each connection portion 230 may be the same as or different from each other. That is, the position of the first connection portion 230 in the direction intersecting the width direction at the first position A and the position of the second connection portion 230 in the direction intersecting the width direction at the first position A may be the same as or different from each other. Similarly, the position of the first connection portion 230 in the direction intersecting the width direction at the second position B may be the same as or different from each other.

[0099] In the traction jig 201 according to this embodiment, the connection portion 230 is configured to be displaced along the guide portion, and therefore, the connection portion 230 can realize a mechanism with a simple configuration that can change its position in a direction intersecting the width direction.

[0100] In the towing jig 201 according to this embodiment, the fastener 232 is fastened or loosened to the shaft portion 231a, thereby realizing a mechanism with a simple configuration for displacing and fixing the position of the connection portion 230 in a direction intersecting the width direction relative to the base portion 210.

[0101] In the optical branching cable 1 according to this embodiment, the branching cord bag 30 is formed with a fifth hook-and-loop fastener portion 32e and a sixth hook-and-loop fastener portion 32f, which are outer hook-and-loop fastener portions. Furthermore, in the optical branching cable set according to this embodiment, when the optical branching cables are arranged in parallel, the branching cord bags 30 of adjacent optical branching cables 1 are connected to each other by the fifth hook-and-loop fastener portion 32e and the sixth hook-and-loop fastener portion 32f. Therefore, when the optical branching cable set is pulled, the multiple optical branching cables 1 can move together. Thus, the optical branching cable set according to this embodiment facilitates the manufacture of an optical branching cable set for laying multiple optical branching cables 1 in a parallel arrangement.

[0102] Note that even if the position of the first branch cord bag 30A is aligned, the position of the nth branch cord bag 30N does not necessarily align in a direction intersecting the width direction (i.e., completely adjacent). As illustrated in Fig. 14, the position of the nth branch cord bag 30N may be misaligned in the longitudinal direction of the optical branch cable 1. However, in the optical branch cable set according to this embodiment, the fifth hook-and-loop fastener portion 32e and the sixth hook-and-loop fastener portion 32f extend along the longitudinal direction of the main cable 10. Therefore, even if the branch portions are misaligned in the longitudinal direction of the optical branch cable 1, the branch cord bags 30 can be easily coupled to each other.

[0103] (Modification of optical branching cable) Next, a modified example of the optical branching cable set will be described. Fig. 15 is a perspective view of an optical branching cable set 300 according to the modified example. Fig. 16 illustrates the optical branching cable set 300 according to the modified example and a branching cord bag 330.

[0104] The optical branching cable set 300 according to the modified example includes 22 optical branching cables 301. The optical branching cable 301 according to the modified example differs from the optical branching cable 1 according to the embodiment shown in Fig. 9 in that one branching cord bag 330 is shared by the plurality of optical branching cables 301. In other words, one branching cord bag 330 houses 22 branching cord portions 320.

[0105] Fig. 17 illustrates an example of the arrangement of the branch cord portions 320 of each optical branch cable 301. For ease of explanation, the optical branch cables 301 will be referred to as the first optical branch cable, the second optical branch cable, ..., the twenty-second optical branch cable in the order in which they are arranged from left to right on the page of Fig. 17. Similarly, the branch cord portions 320 included in the first optical branch cable, the second optical branch cable, ..., the twenty-second optical branch cable will be referred to as the first branch cord portion 320A, the second branch cord portion 320B, ..., the twenty-second branch cord portion 320V.

[0106] 17, the branch cord portions 320 are arranged in three rows in the longitudinal direction of the optical branch cable 301. The top row includes branch cord portions 320 from the first branch cord portion 320A to the seventh branch cord portion 320G. The center row includes branch cord portions 320 from the eighth branch cord portion 320H to the fourteenth branch cord portion 320N. The bottom row includes branch cord portions 320 from the fifteenth branch cord portion 320O to the twenty-second branch cord portion 320V. Each branch cord portion 320 is wound clockwise in a coil shape in a plan view.

[0107] The branch cord portions 320 should be arranged so that the bending radius is as large as possible. For example, in the left column, the first branch cord portion 320A is arranged farthest from the branch portion BR. The first branch cord portion 320A through the seventh branch cord portion 320G are arranged in order of increasing distance from the branch portion BR. In other words, the seventh branch cord portion 320G is arranged closest to the branch portion BR.

[0108] Similarly, in the center column, the eighth branch cord portion 320H is arranged farthest from the branch portion BR. The eighth branch cord portion 320H through the fourteenth branch cord portion 320N are arranged in the order of furthest from the branch portion BR. In other words, the fourteenth branch cord portion 320N is arranged closest to the branch portion BR. Furthermore, in the right column, the fifteenth branch cord portion 320O is arranged farthest from the branch portion BR. The fifteenth branch cord portion 320O through the twenty-second branch cord portion 320V are arranged in the order of furthest from the branch portion BR. In other words, the twenty-second branch cord portion 320V is arranged closest to the branch portion BR.

[0109] By arranging the branch cord sections 320 in this manner, the branch cord section 320 arranged closest to the branch section BR is the branch cord section 320 of the rightmost optical branch cable 301 in each row. In this case, when the branch cord section 320 is wound clockwise into a coil, the branch cord section 320 arranged closest to the branch section BR is less likely to be subjected to excessive small-diameter bending.

[0110] Furthermore, when removing the branch cord sections 320, the branch cord sections 320 are arranged in order, so when connecting the branch cord sections 320 to the server rack 120, etc., it is difficult to mix up the branch cord sections 320, making the connection work of the branch cord sections 320 easy.

[0111] In the optical branching cable 301 according to the modified example, one branching cord bag 330 houses all of the branching cord sections 320, so when the optical branching cable set 300 is pulled, the multiple optical branching cables 301 tend to move together.

[0112] Although the present disclosure has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the present disclosure. Furthermore, the number, position, shape, etc. of the components described above are not limited to the above embodiments, and can be changed to the number, position, shape, etc. that are suitable for implementing the present disclosure.

[0113] In the present embodiment, a case where the optical branching cable 1 is laid using the pulling jig 201 has been described as an example, but the cable laid using the pulling jig 201 is not limited to the optical branching cable 1. For example, an optical cable that does not include a branching cord portion may be pulled using a pulling jig while maintaining the parallel state.

[0114] In this embodiment, the connection portion 230 can be fixed at a first position A and a second position B on the guide slit GS, but the connection portion 230 may be fixable at three or more points on the guide slit GS, and each connection portion 230 may be fixable at at least two or more different positions on the guide slit GS. [Explanation of symbols]

[0115] 1,301 optical branching cables 10 Main Cable 11 Optical cord 11A optical fiber core 12 Tensile strength body 13 Tape 13A First end 13B Second end 14 First Bundle 15 Optical Code Group 16 Second Bundle 17 Core 18 Cable hook-and-loop fastener 20,320 Branch code section 21 Optical Connector 30,330 Branch cord bag 30A First Branch Cord Bag 30N nth branch cord bag 31 Main Surface 32a First hook-and-loop fastener 32b Second hook-and-loop fastener 32c Third hook-and-loop fastener 32d Fourth hook-and-loop fastener 32e Fifth hook-and-loop fastener 32f Sixth hook-and-loop fastener 40 Regulated Parts 41 Mounting part 42 Regulatory Department 43 Main body 44 Connector passage 50 Tip Bag 60 connecting loop 100 Optical Communication System 110 Distribution board 120 Server Racks 201 Towing Jig 210 base 211 Engaged part 220 Traction section 230 Connection 231 Positioning part 231a Shaft 231b Engagement part 232 Fixtures 300 Optical Branch Cable Set 320A First Branch Code 320B Second branch cord section 320G seventh branch cord 320H 8th branch cord section 320N 14th branch cord section 320O 15th Branch Code Section 320V 22nd branch cord part Join operation O1

Claims

1. a plurality of optical cords each including at least one optical fiber; A tension member; a tape forming the outermost layer; a main cable comprising: an optical branch cable including a branch cord portion in which at least one optical fiber core is led out from the optical cord of the main cable to an outer side than the outermost layer, an optical cord group including a plurality of the optical cords bound together in a first bundle; a core portion including the optical cord group bound together by a second bundle and the tensile strength member, The tape is longitudinally wrapped around the core portion to cover the core portion. Optical branching cable.

2. a slit is formed in the tape at a position corresponding to a branch portion through which the branch cord portion is led out from the main cable; the slit extends along a circumferential direction of the main cable in a part of the circumferential direction of the tape, The branch cord portion is led out from the main cable through the slit. The optical branch cable according to claim 1 .

3. The slit is formed in the overlapping portion of the longitudinally wrapped tape from the circumferential end of the inner layer portion to the circumferential end of the outer layer portion. The optical branch cable according to claim 2 .

4. an optical connector provided at a tip of the branch cord portion; a branch cord bag capable of storing at least a portion of the branch cord portion in a coiled state, The optical branch cable according to claim 1 .

5. At least one surface of the branch cord bag is semicircular in shape. The optical branch cable according to claim 4 .

6. The inner surface of the branch cord bag and the main cable are connected by a hook-and-loop fastener. The optical branch cable according to claim 4 .

7. a mounting portion that can be attached to the main cable; a bend restricting portion that restricts the branch cord from bending at a radius less than a predetermined bend radius; a main body portion formed along an outer shape of the main cable and defining, together with the bend restricting portion, a connector passing portion which is a hole through which the optical connector can pass; a bend restricting part provided with the above-mentioned components is attached to a position corresponding to the branch part through which the branch cord part is led out from the main cable, The optical branch cable according to claim 4 .

8. An optical branching cable set in which a plurality of optical branching cables according to any one of claims 1 to 7 are arranged in parallel in a direction intersecting a longitudinal direction, the optical branch cable includes a branch cord bag capable of storing at least a portion of the branch cord portion in a coiled state; An outer surface fastener portion is formed on the outer surface of each of the branch cord bags, The branch cord bags of adjacent optical branch cables are connected to each other by the outer surface fastener portion. Optical branching cable set.

9. The outer surface fastener portion is formed to extend in the longitudinal direction.

9. The optical branch cable set according to claim 8.

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