Optical cable member, pulling member, and pulling method

Abstract

An optical cable member (1) that has an optical cable (10), a fixing member (20), a first housing tube (30), and a second housing tube (40). The optical cable (10) has optical fibers (11a) that extend in the longitudinal direction and a tensile body (13). The optical cable (10) has, provided along the longitudinal direction thereof: a cable main body (17) that has the optical fibers (11a) and the tensile body (13) housed therein; and a cable-exposed section (18) in which the optical fibers (11a) and the tensile body (13) are exposed to the outside. The fixing member (20) fixes the tensile body (13) in the cable-exposed section (18). The first housing tube (30) is disposed between the fixing member (20) and the cable main body (10), houses the tensile body (13) of the cable-exposed section (18) therein, and has the optical fibers (11a) of the cable-exposed section (18) extending therethrough. The second housing tube (40) is disposed on the opposite side to the first housing tube (30) in the fixed member (20), in the longitudinal direction, and houses the optical fibers (11a) of the cable-exposed section (18) therein. In the optical cable member (1), the second housing tube (40) is a bendable member.

Description

[Technical Field]

[0001] The present disclosure relates to an optical cable member, a pulling member, and a pulling method. This application claims priority to Japanese Application No. 2020-142575, filed on August 26, 2020, and incorporates by reference all of the contents of said Japanese application. [Background technology]

[0002] Patent Documents 1 and 2 disclose an optical cable pulling tool that is attached to one end of an optical cable containing a large number of optical fibers. In this optical cable pulling tool, a high-tension hose is provided on the outside of a connecting structure that fixes a tension member exposed from the optical cable and the optical fibers exposed from the optical cable, thereby protecting the connecting structure and the optical fibers arranged inside the high-tension hose. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-004888 [Patent Document 2] Japanese Patent Application Laid-Open No. 2001-004889 Summary of the Invention

[0004] The present disclosure provides, as one aspect, an optical cable member. The optical cable member includes an optical cable, a fixing member, a first storage tube, and a second storage tube. The optical cable has an optical fiber and a strength member extending in the longitudinal direction. The optical cable includes a cable main body portion in which the optical fiber and the strength member are stored inside, and a cable exposed portion in which the optical fiber and the strength member are exposed to the outside, arranged along the longitudinal direction. The fixing member fixes the strength members in the cable exposed portion. The first storage tube is disposed between the fixing member and the cable main body portion, and stores the strength members in the cable exposed portion, and the optical fiber in the cable exposed portion extends therein. The second storage tube is disposed on the opposite side of the fixing member from the first storage tube in the longitudinal direction, and stores the optical fiber in the cable exposed portion therein. In this optical cable member, the second storage tube is a bendable member.

[0005] In another aspect, the present disclosure provides a pulling member for pulling an optical cable having an optical fiber and a strength member. The pulling member includes a fixing member configured to fix the strength member of the optical cable, a first housing tube attached to a first end of the fixing member, and a second housing tube attached to a second end of the fixing member opposite the first end. In this pulling member, the second housing tube is a bendable member.

[0006] In yet another aspect, the present disclosure relates to a method for pulling an optical cable using the above-mentioned optical cable member, the pulling method including: passing the optical cable through a laying pipe; and removing the second storage tube of the optical cable from the fixing member after the optical cable has passed through the laying pipe, thereby exposing a tip portion of the optical fiber. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a perspective view showing an optical cable member according to an embodiment. [Figure 2] FIG. 2 is an exploded perspective view of the optical cable member shown in FIG. [Figure 3] FIG. 3 is a cross-sectional view showing an example of an optical cable of the optical cable member. [Figure 4]FIG. 4 is a side view schematically showing the optical cable shown in FIG. [Figure 5] FIG. 5 is a perspective view showing an example of a fixing member of an optical cable member. [Figure 6] FIG. 6 is a cross-sectional view showing a state in which the tension member of the optical cable is fixed to the pin of the fixing member. [Figure 7] FIG. 7 is a perspective view showing an example of attaching an optical cable to a fixing member. [Figure 8] FIG. 8 is a plan view of the fixing member shown in FIG. 5 as viewed from the optical cable side. [Figure 9] FIG. 9 is a schematic side view showing the inside of the first storage tube and the second storage tube of the optical cable member, and shows an enlarged example of a large number of optical fibers stored in the second storage tube. [Figure 10] FIG. 10 is a perspective view showing an example of a metal flexible tube used for the first storage tube and the second storage tube of the optical cable member. [Figure 11] FIG. 11 is a diagram for explaining an outline of a method for inserting an optical cable member into a laying pipe and pulling it. [Figure 12] FIG. 12 is a cross-sectional view showing another example of an optical cable used in the optical cable member. DETAILED DESCRIPTION OF THE INVENTION

[0008] [Problem to be solved by this disclosure] The optical cable pulling tool disclosed in Patent Document 1 and the like tends to have a large outer diameter because it covers the cable fixing part with a high-tension hose, and although it can protect the internal structure, it can be difficult to move when inserting and pulling the optical cable into the installation pipe. For example, if the installation pipe is thin, if another cable is already installed inside the installation pipe, or if the installation pipe is bent partway through, the optical cable pulling tool disclosed in Patent Document 1 and the like may get stuck in the middle, making it difficult to perform the pulling operation smoothly.

[0009] [Effects of this disclosure] According to the present disclosure, it is possible to smoothly perform the pulling operation when laying an optical cable.

[0010] [Description of the embodiments of the present disclosure] First, the details of the embodiments of the present disclosure will be listed and described. An optical cable member according to one embodiment of the present disclosure includes an optical cable, a fixing member, a first storage tube, and a second storage tube. The optical cable has an optical fiber and a strength member extending in the longitudinal direction. The optical cable includes a cable main body in which the optical fiber and the strength member are stored inside, and an exposed cable portion in which the optical fiber and the strength member are exposed to the outside, arranged along the longitudinal direction. The fixing member fixes the strength members of the exposed cable portion. The first storage tube is disposed between the fixing member and the cable main body, and stores the strength members of the exposed cable portion therein, and the optical fiber of the exposed cable portion extends therein. The second storage tube is disposed on the opposite side of the fixing member from the first storage tube in the longitudinal direction, and stores the optical fiber of the exposed cable portion therein. In this optical cable member, the second storage tube is a bendable member.

[0011] A pulling member according to an embodiment of the present disclosure is a pulling member for pulling an optical cable having an optical fiber and a strength member. This pulling member includes a fixing member configured to fix the strength member of the optical cable, a first storage tube attached to a first end of the fixing member, and a second storage tube attached to a second end of the fixing member opposite the first end. In this pulling member, the second storage tube is a bendable member.

[0012] A pulling method according to an embodiment of the present disclosure is a method for pulling an optical cable using the above cable member, and includes the steps of: passing the optical cable through a facility pipe; and removing the second storage tube of the optical cable from the fixing member after the optical cable has passed through the facility pipe, thereby exposing a tip portion of the optical fiber.

[0013] In the above-described optical cable member or pulling member, the second storage tube located at the tip side and storing the optical fiber is a bendable member. Therefore, when a wire or the like is attached to the tip of the optical cable member and the optical cable is introduced into the installation pipe, even if the installation pipe is narrow or bent, the second storage tube can bend as necessary during the pulling operation, allowing for smooth movement. Therefore, the above-described optical cable member, pulling member, and pulling method make it possible to smoothly perform the pulling operation when laying the optical cable.

[0014] In one embodiment, the first storage pipe may be a bendable member, and the minimum bending radius of the first storage pipe may be smaller than the minimum bending radius of the optical cable. In this case, the first storage pipe on the optical cable side can also be bent as needed depending on the pipe it is installed in. The minimum bending radius of the second storage pipe may also be smaller than the minimum bending radius of the optical cable. Furthermore, the minimum bending radius of the first storage pipe may be, for example, 300 mm or more and 500 mm or less, and the minimum bending radius of the second storage pipe may be, for example, 200 mm or more and 500 mm or less. Note that the "minimum bending radius" used here refers to the radius at the limit at which the optical properties of the optical fiber housed therein are maintained in the case of an optical cable, and the radius at the limit at which the storage pipe can be bent without breaking, and each refers to the bending radius at the central axis of the member.

[0015] In one embodiment, the first storage tube may have an outer diameter smaller than the outer diameter of the second storage tube. The first storage tube may also have an outer diameter smaller than twice the outer diameter of the cable main body. In this case, the first storage tube on the optical cable side is made thinner, closer to the outer diameter of the optical cable, and can be handled as substantially the same as the optical cable when inserted into the installation pipe and pulled. As a result, the pulling operation when laying the optical cable can be performed more smoothly.

[0016] In one embodiment, the second storage tube may be three times or more as long as the first storage tube. In this case, even when an optical cable having a sufficient length of exposed optical fiber is inserted into the laying pipe, the optical cable can be smoothly pulled through the laying pipe. Furthermore, an optical cable member having a sufficient length of exposed optical fiber makes it easier to attach the optical fiber to an optical device and perform optical wiring after the pulling operation.

[0017] In one embodiment, the fixing member may include a pin that fixes the tip of the strength member in the exposed cable portion and a fixing main body located between the first storage tube and the second storage tube. The fixing main body may include a first attachment portion to which the first storage tube is attached and a second attachment portion to which the second storage tube is attached, and may be configured so that the pin can be attached from the first attachment portion side. The fixing main body may be provided with at least one through hole extending along the longitudinal direction, and the optical fiber in the exposed cable portion may extend from the first storage tube to the second storage tube through the through hole. In this case, the configuration for fixing the strength member and the configuration for passing the optical fiber can be simplified. Furthermore, the fixing work of the strength member can be easily performed.

[0018] In one embodiment, the optical cable member may further include a connecting member attached to the tip of the second storage tube. The connecting member, the second storage tube, and the fixing member may be configured so that a tensile force applied to the connecting member is transmitted to the strength member via the second storage tube and the fixing member. In this case, even if a twist due to tension is applied to the second storage tube or the like during a pulling operation, the tensile force or twist is transmitted directly to the strength member rather than from outside the optical cable, thereby preventing the optical cable itself from being pulled or twisted. As a result, it is possible to prevent unnecessary tension or twisting or the resulting deformation of the optical fiber in the optical cable, which could degrade the optical transmission characteristics.

[0019] In one embodiment, an optical connector may be attached to the tip of the optical fiber in the exposed cable portion, and the optical connector may be stored in the second storage tube. The second storage tube may be attached to the fixing member so as to be detachable from the fixing member. In this case, when the optical cable member is moved within the laying pipe and reaches the target location, the second storage tube can be removed, making it possible to easily take out the optical connector required for subsequent work, thereby improving work efficiency.

[0020] In one embodiment, at least one of the first outer circumferential region where the first storage tube is fixed to the fixing member and the second outer circumferential region where the second storage tube is fixed to the fixing member may be covered with waterproof tape, which can more reliably prevent moisture and the like from entering the optical cable.

[0021] [Details of the embodiments of the present disclosure] Hereinafter, an embodiment of the present disclosure will be described in detail with reference to the accompanying drawings. The present invention 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. In the following description, the same elements or elements having the same functions will be designated by the same reference numerals, and redundant explanations will be omitted.

[0022] An example of an optical cable member according to this embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a perspective view showing the optical cable member 1. FIG. 2 is an exploded perspective view of the optical cable member 1. As shown in FIGS. 1 and 2, the optical cable member 1 includes an optical cable 10, a fixing member 20, a first storage tube 30, a second storage tube 40, cable attachments 51 and 52, a cover 53, and a connecting member 54. FIGS. 1 and 2 show only one end of the optical cable 10, and other components are omitted. The optical cable member 1 is a member for inserting the optical cable 10 into a laying tube 60 and pulling the optical cable 10 to a predetermined position using a wire 56 connected to the connecting member 54 (see FIG. 11). The tip end (optical connector 16) of the optical cable 10 pulled to the predetermined position is optically connected to a predetermined device or the like. As an example, the optical cable member 1 including the optical cable 10 is used to optically connect data centers. The following describes the configuration of the optical cable member 1 at one end of the optical cable 10, but a similar configuration may be provided at the other end of the optical cable 10. The components of the optical cable member 1 excluding the optical cable 10 are the pulling member 5. That is, the pulling member 5 is configured to include a fixing member 20, a first storage tube 30, a second storage tube 40, cable attachments 51 and 52, a cover 53, and a connecting member 54.

[0023] As shown in FIGS. 3 and 4 , the optical cable 10 includes a fiber unit 11, which is a bundle of multiple optical fibers 11a, a spacer 12, a strength member 13, a jacket 14, and a water-absorbing tape 15. The fiber unit 11, the spacer 12, the strength member 13, the jacket 14, and the like are configured to extend in the longitudinal direction (the direction perpendicular to the plane of FIG. 3 ). The length of the optical cable 10 along the longitudinal direction may be, for example, 0.5 km or more and 3.0 km or less. The optical cable 10 includes, for example, multiple fiber units 11 (eight fiber units 11 in this embodiment), and each fiber unit 11 houses multiple optical fibers 11a. When the optical cable 10 is used in, for example, a data center, the optical cable 10 may have a total of 1,000 or more optical fibers 11a, for example, 1,728 or 3,456 optical fibers 11a, and these multiple optical fibers 11a are housed separately in each fiber unit 11.

[0024] The spacer 12 is a component that extends longitudinally together with the fiber units 11 to align the fiber units 11, and has multiple protrusions (star-shaped) that protrude from the inside to the outside in a radial direction perpendicular to the longitudinal direction. Each fiber unit 11 is housed in a groove defined by a pair of adjacent protrusions of the spacer 12. The spacer 12 is formed from a resin such as polyethylene resin. A round rod-shaped tension member 13 is embedded in the center of the spacer 12 and is integrated with the spacer 12. The tension member 13 is a component that supports external loads (such as tension and twist) applied to the optical cable 10, and extends longitudinally together with the fiber units 11 and spacers 12. The tension member 13 reduces external loads applied to the optical fibers 11a of the fiber units 11, the spacers 12, and the like, thereby protecting them. The tension member 13 is formed from, for example, metal (such as steel) or fiber-reinforced plastic (FRP). The tension members 13 may be provided separately from the spacer 12, or may be provided inside or outside the groove of the spacer 12.

[0025] The jacket 14 houses the multiple fiber units 11, spacers 12, and tension members 13 inside, and is a part that protects these components from external radial loads and intrusions (e.g., water), and is made of, for example, resin. The water-absorbing tape 15 is a tape for absorbing moisture that has infiltrated into the optical cable 10. The water-absorbing tape 15 is placed between the fiber units 11 and the jacket 14, and protects the optical fibers 11a of the fiber units 11 from moisture and the like.

[0026] 4, the optical cable 10 having the above configuration has a cable main body 17 in which the fiber unit 11 (optical fiber 11a), spacer 12, and strength members 13 are housed within the jacket 14, and a cable exposed portion 18 in which the jacket 14 is removed and the fiber unit 11 (optical fiber 11a), spacer 12, and strength members 13 are exposed to the outside. In the cable exposed portion 18, the strength members 13 are exposed so as to protrude from the end of the jacket 14, and the fiber unit 11 is exposed so as to protrude further from the jacket 14 than the strength members 13. In other words, the exposed fiber unit 11 is longer than the exposed strength members 13.

[0027] An optical connector 16 is attached to the tip of the exposed fiber unit 11. As an example, the optical connector 16 is an MPO connector compatible with 12 or 24 cores. Each optical connector 16 is stored in the second storage tube 40, but in order to efficiently utilize the space in the second storage tube 40, the optical connectors 16 may be connected to the fiber units 11 (optical fibers 11a) at different positions in the longitudinal direction (with steps). In other words, the optical connectors 16 may be attached so that the lengths of the exposed portions of the fiber units 11 (optical fibers 11a) differ to form steps.

[0028] As shown in FIG. 2, the fixing member 20 is a member that fixes one end of the strength member 13 in the exposed cable portion 18. The fixing member 20 is disposed between the first storage tube 30 and the second storage tube 40 and is attached to each of the first storage tube 30 and the second storage tube 40. As shown in FIGS. 2 and 5, the fixing member 20 has a pin 21 and a fixing main body 22. Both the pin 21 and the fixing main body 22 are made of metal. The fixing member 20 is configured so that the tip of the pin 21 can be inserted into the fixing main body 22. As shown in FIG. 6, the pin 21 is a round bar member having an inner hole 21a. The tip of the strength member 13 inserted into the inner hole 21a is fixed by caulking and / or adhesive, thereby fixing the exposed end of the strength member 13 of the optical cable 10 to the fixing member 20. As shown in FIG. 7, the strength member 13 is fixed to the pin 21 and then to the fixing main body 22.

[0029] As shown in FIG. 5 , fixed main body 22 includes a cylindrical central portion 23, a first attachment portion 24 on the first storage pipe 30 side of central portion 23, and a second attachment portion 25 on the second storage pipe 40 side of central portion 23. First attachment portion 24 and second attachment portion 25 are also cylindrical, but are formed to have a smaller outer diameter than central portion 23. Second end portion 32 of first storage pipe 30 is attached to first attachment portion 24, and first end portion 41 of second storage pipe 40 is attached to second attachment portion 25. More specifically, second end portion 32 of first storage pipe 30 is removably fixed to first attachment portion 24 by aligning through-holes 32a of second end portion 32 of first storage pipe 30 with screw holes 24a (four screw holes 24a in this embodiment) provided at equal intervals on the outer periphery of first attachment portion 24 and fastening with screws 32b. Similarly, by aligning through-hole 41a of first end 41 of second storage pipe 40 with screw holes 25a (four screw holes 25a in this embodiment) provided at equal intervals on the outer periphery of second attachment portion 25 and fastening with screws 41b, first end 41 of second storage pipe 40 is removably fixed to second attachment portion 25. Waterproof tape 55 may be attached to the outer periphery (first outer periphery region, second outer periphery region) of fixing member 20 to which first storage pipe 30 and second storage pipe 40 are fixed (see FIG. 11).

[0030] As shown in Fig. 5, a through hole 26 is provided inside the fixing main body 22 of the fixing member 20. The fiber unit 11 (optical fiber 11a) of the exposed cable portion 18 passes through the through hole 26 and extends from the first storage tube 30 to the second storage tube 40. On the first storage tube 30 side, the through hole 26 is divided into a pair of through holes 26a, 26b, as shown in Fig. 8, and the pin 21 is fixed in the center thereof.

[0031] As shown in FIGS. 1 and 2 , the first storage tube 30 is a tubular member disposed between the fixing member 20 and the cable main body 17 of the optical cable 10. The first end 31 is attached to the cable main body 17 of the optical cable 10 by cable attachments 51 and 52, and the second end 32 is attached to the fixing member 20 by screws or the like as described above. As shown in FIG. 9 , the first storage tube 30 accommodates the strength members 13 of the exposed cable portion 18 therein, and the fiber unit 11 (optical fiber 11a) of the exposed cable portion 18 extends therethrough. Although not shown in FIG. 9 , the fiber unit 11 in the first storage tube 30 is disposed radially outward of the strength members 13 and pins 21 and extends toward the second storage tube 40. The strength members 13 are fixed to the pins 21 of the fixing member 20 within the first storage tube 30, for example. As described above, the fiber unit 11 (optical fiber 11a) extends from the first storage tube 30 so as to be drawn out to the second storage tube 40 through the through-hole 26 of the fixing member 20. The first storage tube 30 is configured to be resistant to lateral pressure in order to protect the fiber unit 11, spacer 12, tensile strength member 13, pins 21 of the fixing member 20, etc. stored therein from pressure applied from the outside in the radial direction. The "lateral pressure resistance" of the first storage tube 30 is preferably such that it will not break even when a force of 1000 N is applied over a 30 cm length, and more preferably such that it will not break even when a force of 1500 N is applied.

[0032] On the other hand, the first storage tube 30 is configured to be bendable. For example, as shown in FIG. 10 , the first storage tube 30 is composed of a flexible metal hose, which is a hose made of interlocking metals or the like so that it can be bent. The first storage tube 30 may also be a flexible hose other than metal, as long as it has a predetermined lateral pressure resistance. The first storage tube 30 is preferably one that will not break even when bent while being pulled at 1000 N, and more preferably one that will not break even when being pulled at 1200 N. The minimum bending radius of the first storage tube 30 may be smaller than the minimum bending radius of the optical cable 10. As used herein, the term "minimum bending radius" refers to the radius at which the optical properties of the optical fiber housed therein are maintained for an optical cable, and the radius at which the optical cable can be bent without being damaged for a storage tube, and refers to the bending radius at the central axis of each component. The first storage tube 30 has a larger outer diameter than the optical cable 10, and there is a space between the first storage tube 30 and the optical cable 10. Therefore, even when the first storage tube 30 is bent, the bending of the optical cable 10 housed therein is usually more gradual. Therefore, the minimum bending radius of the first storage tube 30 can be made smaller than the minimum bending radius of the optical cable 10. On the other hand, the smaller the minimum bending radius of the first storage tube 30, the easier it is to pass through the conduit and the better the traction characteristics. For example, if the minimum bending radius (mm) of the optical cable 10 is R450, the minimum bending radius of the first storage tube 30 is, for example, R300 to R500 (300 mm to 500 mm), more preferably R300 to R400 (300 mm to 400 mm). Furthermore, the first storage tube 30 preferably has an outer diameter smaller than the outer diameter of the second storage tube 40 so that it can be handled in substantially the same way as the optical cable 10, and preferably has an outer diameter smaller than twice the outer diameter of the cable main body 17. However, the outer diameter of the first storage tube 30 may be the same as the outer diameter of the second storage tube 40. The length of the first storage tube 30 in the longitudinal direction may be, for example, 20 cm or more and 40 cm or less, and may be shorter than that of the second storage tube 40.

[0033] As shown in FIGS. 1 and 2, the second storage tube 40 is a cylindrical protective member arranged on the opposite side of the fixing member 20 in the longitudinal direction from the first storage tube 30. As described above, the first end 41 is attached to the fixing member 20 with screws or the like, and the second end 42 is similarly attached to the cover 53 with through-holes 42a and screws 42b or the like. As shown in FIG. 9, the second storage tube 40 stores the fiber units 11 (optical fibers 11a) of the exposed cable portion 18 therein. In the second storage tube 40, optical connectors 16 are attached to the ends of the fiber units 11, and the fiber units 11 with the optical connectors 16 are stored in the second storage tube 40 in a stepped manner. In other words, the fiber units 11 are stored so that the positions of the optical connectors 16 are offset in the longitudinal direction. However, it is not necessary for the positions of all the optical connectors 16 to be offset from one another. The fiber units 11 stored in the second storage tube 40 are held in a packed state without being fixed to the second storage tube 40, but may be fixed to the second storage tube 40.

[0034] The second storage tube 40 is formed, for example, from a metal tube so as to have resistance to lateral pressure to protect the fiber unit 11 and other components stored therein from external pressure, as well as resistance to bending tension generated when towing. The second storage tube 40 is also configured to be bendable, for example, from a metal flexible hose as shown in FIG. 10. The second storage tube 40 is preferably one that will not break even when bent while being pulled with a force of 1000 N. Regarding lateral pressure resistance, for example, the second storage tube 40 should have strength such that it will not break even when a force of 1000 N is applied over a 30 cm length, and more preferably, it should not break even when a force of 1500 N is applied. The minimum bending radius of the second storage tube 40 may be smaller than the minimum bending radius of the optical cable 10. The second storage tube 40 accommodates the fiber unit 11 (optical fiber 11a) and the optical connector 16 attached to its tip. Because there is a space between the second storage tube 40 and the fiber unit 11 (optical fiber 11a) and the optical connector 16 attached to its tip, the minimum bending radius of the second storage tube 40 can be made smaller than the minimum bending radius of the optical cable 10. The smaller the minimum bending radius of the second storage tube 40, the easier it is to pass through the conduit, resulting in better traction characteristics. When the minimum bending radius (mm) of the optical cable 10 is R450, the minimum bending radius (mm) of the second storage tube 40 is, for example, R200 to R500 (200 mm to 500 mm), and more preferably R300 to R450 (300 mm to 450 mm).

[0035] The second storage tube 40 has an outer diameter larger than that of the first storage tube 30 in order to store the fiber unit 11 to which the optical connector 16 is attached. The outer diameter of the second storage tube 40 may be the same as that of the first storage tube 30. The longitudinal length of such a second storage tube 40 may be, for example, 1 m or more and 5 m or less, and may be three times or more the length of the first storage tube 30. Having such a length facilitates installation and allows for appropriate wiring when installing the fiber unit 11 in an optical device after towing. Furthermore, since the second storage tube 40 is attached to the fixing member 20 with screws or the like, it can also be easily removed from the fixing member 20 after towing.

[0036] 1 and 2, a connecting member 54 is further provided at the second end 42 of the second storage tube 40 via a lid portion 53. The connecting member 54 has an opening for attaching a wire 56 used to pull the optical cable member 1, and the optical cable member 1 can be pulled by hooking the wire 56 into this opening and pulling it in a predetermined direction.

[0037] Here, with reference to FIG. 11 , a method for pulling the optical cable member 1 having the above-described configuration and its effects will be described. As shown in FIG. 11 , for example, other cables 61 and 62 may already be laid in the laying pipe 60. Furthermore, the laying pipe 60 may be narrow or bent. With a conventional optical cable member (pulling member), the outer tube is hard and inflexible, so the pulled optical cable may get stuck midway, hindering smooth pulling operations. In contrast, when pulling an optical cable 10 using the optical cable member 1 according to this embodiment, a wire 56 or the like is first attached to the tip of the optical cable member 1, and the optical cable 10 is passed through the laying pipe 60. At this time, the second storage pipe 40 located at the tip of the optical cable member 1 and housing the fiber unit 11 (optical fiber 11a) is at least a bendable member. Therefore, even if the inside of the laying pipe 60 is narrow or bent, the leading second storage pipe 40 can bend as needed during the pulling operation, allowing for smooth movement. Then, after the optical cable 10 has been pulled through the installation tube 60 to a predetermined position, the second storage tube 40 of the optical cable member 1 is removed from the fixing member 20, and the tip portion of the optical fiber 11a (including the optical connector 16, etc.) is exposed for a predetermined connection. In this way, the optical cable member 1 allows for smooth pulling work when laying the optical cable 10.

[0038] In this embodiment, the first storage pipe 30 may be a bendable member. In this case, the first storage pipe 30 on the optical cable 10 side can also be bent as needed depending on the shape and size of the installation pipe 60. Also, in this embodiment, the minimum bending radius of the first storage pipe 30 may be smaller than the minimum bending radius of the optical cable 10. In this case, the pulling operation when installing the optical cable 10 can be performed even more smoothly.

[0039] In this embodiment, the first storage tube 30 may have an outer diameter smaller than the outer diameter of the second storage tube 40. Alternatively, the first storage tube 30 may have an outer diameter smaller than twice the outer diameter of the cable main body 17. In this case, the first storage tube 30 on the optical cable 10 side is made thinner, closer to the outer diameter of the optical cable 10, and can be handled as substantially the same as the optical cable 10 when inserted into the laying tube 60 and pulled. As a result, the pulling operation when laying the optical cable 10 can be performed even more smoothly.

[0040] In this embodiment, the minimum bending radius of the second storage tube 40 may be smaller than the minimum bending radius of the optical cable 10. Furthermore, the second storage tube 40 may have a length three times or more that of the first storage tube 30. In this case, even when the optical cable 10 having a sufficient length of exposed optical fiber is inserted into the laying tube 60, the second storage tube 40 can be bent appropriately, making it possible to smoothly perform the pulling operation of the optical cable 10 inside the laying tube 60. Furthermore, since the optical cable member 1 has a sufficient length of exposed optical fiber, it becomes easier to attach the optical fiber to an optical device and perform optical wiring, etc. after the pulling operation.

[0041] In this embodiment, the fixing member 20 includes a pin 21 that fixes the tip of the strength member 13 in the exposed cable portion 18 and a fixing main body 22 located between the first storage tube 30 and the second storage tube 40. The fixing main body 22 includes a first attachment portion 24 to which the first storage tube 30 is attached and a second attachment portion 25 to which the second storage tube 40 is attached, and is configured so that the pin 21 can be attached from the first attachment portion 24 side. The fixing main body 22 is provided with a through-hole 26 extending along the longitudinal direction, and the optical fiber 11a in the exposed cable portion 18 extends from the first storage tube 30 to the second storage tube 40 through the through-hole 26. In this case, the configuration for fixing the strength member 13 and the configuration for passing the optical fiber 11a can be simplified. Furthermore, the fixing operation of the strength member 13 can be easily performed.

[0042] In this embodiment, the optical cable member 1 may further include a connecting member 54 attached to the second end 42 of the second storage tube 40. The connecting member 54, the second storage tube 40, and the fixing member 20 are configured so that a tensile force applied to the connecting member 54 is transmitted to the strength member 13 via the second storage tube 40 and the fixing member 20. That is, the connecting member 54 is fixed non-rotatably to the second end 42 of the second storage tube 40 with a screw or the like, and the first end 41 of the second storage tube 40 is fixed non-rotatably to the fixing member 20 with a screw or the like. The strength member 13 is then fixed to the fixing member 20. Meanwhile, the first storage tube 30, whose second end 32 is fixed to the fixing member 20, has its first end 31 attached to the optical cable 10 (cable main body 17) with cable attachments 51 and 52. The cable attachments 51 and 52 are, for example, waterproof heat-shrinkable tubes. In this case, even if tension or resulting twisting is applied to the second storage tube 40 during a pulling operation or the like, such tension or twisting is transmitted directly to the tensile strength member 13 rather than from the outside of the optical cable 10, thereby preventing tension or twisting of the optical cable 10 itself. As a result, it is possible to prevent unnecessary twisting and the resulting deformation of the optical fiber 11a in the optical cable 10, which could cause damage or a deterioration in the optical transmission characteristics of the optical fiber.

[0043] In this embodiment, an optical connector 16 is attached to the tip of the optical fiber 11a in the cable exposed portion 18, and the optical connector 16 is stored in the second storage tube 40. The second storage tube 40 is attached to the fixing member 20 so as to be detachable from the fixing member 20. Therefore, when the optical cable member 1 is moved inside the laying pipe 60 and reaches a target location, the second storage tube 40 can be removed, and the optical connector 16 required for subsequent work can be easily taken out, thereby improving work efficiency.

[0044] The above describes an optical cable member according to an embodiment of the present disclosure. However, the present disclosure is not limited to the above embodiment and can be modified as appropriate within the spirit and scope of the claims. For example, while the optical cable used in the optical cable member 1 in the above description is the spacer-equipped optical cable 10 shown in FIGS. 3 and 4, the present disclosure may also be applied to optical cables having other configurations. For example, the spacerless optical cable shown in FIG. 12 may also be used. An optical cable 70 according to this modification includes a plurality of fiber units 71 each having a large number of optical fibers, and the plurality of fiber units 71 are housed in an outer jacket 74. A pair of strength members 73 are embedded in the outer jacket 74. The configuration of the optical cable member 1 described above may be applied to one end of this optical cable 70. In this case, the ends of the pair of strength members 73 are fixed by fixing members 20 (pins 21). The other configurations are the same as those described above. Even when such an optical cable 70 is used, the pulling operation when laying the optical cable 70 can be performed smoothly, as described above. [Explanation of symbols]

[0045] 1...Optical cable component 5...Traction member 10,70...optical cable 11,71...Fiber unit 11a...Optical fiber 12...Spacer 13,73…Tensile strength body 14,74...Outer cover 15...Water-absorbing tape 16...Optical connector 17...Cable body 18...Exposed cable 20...Fixing member 21...pin 21a...Inner hole 22…Fixed body part 23...Central part 24...First mounting part 24a...Screw hole 25...Second mounting part 25a...screw hole 26,26a,26b...Through hole 30...1st storage tube 31...First end 32…Second end 32a...Through hole 32b...Screw 40...Second storage tube 41...First end 41a...Through hole 41b...Screw 42…Second end 42a...Through hole 42b...Screw 51, 52...Cable attachment 53...Lid part 54...Connecting member 55...Waterproof tape 56…Wire 60…Laying pipe 61,62...Cable

Claims

1. an optical cable having an optical fiber and a strength member extending in a longitudinal direction, wherein a cable main body portion in which the optical fiber and the strength member are housed inside, and a cable exposed portion in which the optical fiber and the strength member are exposed to the outside are provided along the longitudinal direction; a fixing member that fixes the tensile strength member to the exposed cable portion; a first storage tube disposed between the fixing member and the cable main body, the first storage tube storing the strength members of the exposed cable portion therein and the optical fibers of the exposed cable portion extending therethrough; a second storage tube that is disposed on the opposite side of the fixing member in the longitudinal direction from the first storage tube and that stores the optical fiber of the cable exposed portion therein; the first storage tube is a bendable member, The optical cable member, wherein the second storage tube is a bendable member.

2. the minimum bending radius of the second storage tube is smaller than the minimum bending radius of the optical cable; The optical cable member according to claim 1 .

3. the minimum bend radius allowed for the first storage tube is smaller than the minimum bend radius allowed for the optical cable; The optical cable member according to claim 1 or 2.

4. the first storage tube has an outer diameter smaller than the outer diameter of the second storage tube or smaller than twice the outer diameter of the cable main body; The optical cable member according to claim 1 .

5. the second storage tube has a length three times or more as long as the first storage tube; The optical cable member according to claim 1 .

6. at least one of the first storage pipe and the second storage pipe includes a metal flexible hose; The optical cable member according to claim 1 .

7. the fixing member has a pin that fixes the tip of the tension member of the cable exposed portion, and a fixing main body portion that is located between the first storage tube and the second storage tube, the fixed main body includes a first attachment portion to which the first storage tube is attached and a second attachment portion to which the second storage tube is attached, and is configured so that the pin can be attached to the fixed main body from the first attachment portion side; the fixed main body is provided with at least one through-hole extending along the longitudinal direction, and the optical fiber of the cable exposed portion extends from the first storage tube to the second storage tube through the through-hole; The optical cable member according to claim 1 .

8. a connecting member attached to a tip of the second storage tube, the connecting member, the second storage tube, and the fixing member are configured so that a tensile force applied to the connecting member is transmitted to the tensile member via the second storage tube and the fixing member. The optical cable member according to claim 1 .

9. an optical connector is attached to a tip of the optical fiber of the cable exposed portion, and the optical connector is housed in the second housing tube; the second storage tube is attached to the fixing member so as to be detachable from the fixing member; The optical cable member according to claim 1 .

10. The number of the optical fibers housed in the optical cable is 1000 or more. The optical cable member according to claim 1 .

11. At least one of a first outer circumferential region where the first storage tube is fixed to the fixing member and a second outer circumferential region where the second storage tube is fixed to the fixing member is covered with waterproof tape. The optical cable member according to claim 1 .

12. Both the first outer peripheral region and the second outer peripheral region are covered with the waterproof tape. The optical cable member according to claim 11 .

13. further comprising a cable attachment positioned between the optical cable and the first storage tube; The optical cable member according to claim 1 .

14. A pulling member for pulling an optical cable having an optical fiber and a tension member, a fixing member configured to fix the tensile strength member of the optical cable; a first storage tube attached to a first end of the fixing member; a second storage tube attached to a second end of the fixing member opposite to the first end, the first storage tube is a bendable member, the second storage tube is a bendable member, the fixing member has a pin configured to fix the tip of the tensile strength member, and a fixing main body portion located between the first storage tube and the second storage tube, the fixed main body includes a first attachment portion to which the first storage tube is attached and a second attachment portion to which the second storage tube is attached, and is configured so that the pin can be attached to the fixed main body from the first attachment portion side; The towing member, wherein the fixed body portion is provided with at least one through hole extending from the first mounting portion toward the second mounting portion.

15. The through hole is divided into a pair of through holes each having a semicircular shape. The towing member of claim 14.

16. the minimum bending radius of the second storage tube is 200 mm or more and 500 mm or less; A towing member according to claim 14 or 15.

17. the minimum bending radius of the first storage tube is 300 mm or more and 500 mm or less; A towing member according to any one of claims 14 to 16.

18. the first storage tube has an outer diameter smaller than the outer diameter of the second storage tube, the second storage tube has a length three times or more as long as the first storage tube; A traction member according to any one of claims 14 to 17.

19. At least one of the first storage tube and the second storage tube has a lateral pressure resistance that is strong enough to withstand a force of 1000 N or more applied within a 30 cm length without breaking. A traction member according to any one of claims 14 to 18.

20. a connecting member attached to a tip of the second storage tube, the connecting member, the second storage tube, and the fixing member are configured so that a tensile force applied to the connecting member is transmitted to the tensile member via the second storage tube and the fixing member.

20. A traction member according to any one of claims 14 to 19.

21. the second storage tube is attached to the fixing member so as to be detachable from the fixing member; A traction member according to any one of claims 14 to 20.

22. A method for pulling an optical cable using the optical cable member according to any one of claims 1 to 13, comprising: a step of passing the optical cable through a laying pipe; a step of removing the second storage tube of the optical cable from the fixing member after the optical cable has passed through the installation tube, thereby exposing a tip portion of the optical fiber; A towing method comprising:

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