Fiber optic cables and fiber optic cable manufacturing equipment

Abstract

The purpose of this disclosure is to provide an optical fiber cable (10) in which the optical fiber core (16) is not clamped by the outer sheath (12), thus preventing increased light loss due to bending of the optical fiber core (16). To achieve the above objective, the optical fiber cable (10) of this disclosure is characterized by comprising: a cable core (11) having multiple optical fiber cores (16); an outer sheath (12) covering the cable core (11); and at least two tensioning members (41) having a warping outward from the axial center of the cable core (11) and disposed along the cable core (11) inside the outer sheath (12); the tensioning members (41) are respectively disposed at positions where the axial center of the cable core (11) is clamped by another tensioning member (41).

Description

Technical Field

[0001] This disclosure relates to optical fiber cables and optical fiber cable manufacturing apparatus. Background Technology

[0002] In recent years, in optical fiber communication systems, the transmission capacity has been limited by the nonlinear effects generated in the optical fiber and the optical fiber fuse. Therefore, in order to alleviate this limitation, optical fibers with an increased effective cross-sectional area (hereinafter referred to as Aeff) have been developed (see, for example, Non-Patent Literature 1).

[0003] However, in fiber optic cables, to achieve smaller diameters and lighter weight, slotless structures that eliminate the need for slotted rods to house the optical fibers have been developed and put into practical use (see, for example, Patent Document 1). Fiber optic cables incorporate tensioning members to protect the fiber core from temperature changes and tension applied during installation. Unlike conventional cables where the tensioning member is located inside the slotted rod, in slotless fiber optic cables, the tensioning member is located inside the outer sheath.

[0004] Furthermore, the connection of fiber optic cables is accompanied by their disassembly. When disassembling cables, it's necessary to consider avoiding increased optical loss due to bending. As one method, in slotless fiber optic cables, the risk of increased optical loss is reduced by installing fibers that suppress bending losses.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Invention Patent No. 4774337 (NTT)

[0008] Non-patent literature

[0009] Non-patent document 1: T.Kato, M.Hirano, M.Onishi and M.Nishimura, "Ultra lownonlinearity low loss pure silica core fiber for long-haul WDM transmission," Fifth Asia-Pacific Conference on... and Fourth Optoelectronics and Communications Conference on Communications,,Beijing,China,1999,pp.1575-1576vol.2,doi:10.1109 / APCC.1999.820589. Summary of the Invention

[0010] The problem the invention aims to solve

[0011] However, certain types of optical fibers, such as those with reduced transmission capacity limitations, are prone to increased light loss due to bending. Therefore, the risk of increased light loss during fiber optic cable disassembly cannot be reduced. For example, during the removal of the fiber core, if the outer sheath rigidly returns to its original position, it may trap the fiber core being removed from the crack, increasing light loss due to bending. This risk is further amplified in slotless fiber optic cables, where the clamping force is greater due to the integrated sheath and tensioning components.

[0012] To address the aforementioned issues, the present disclosure aims to provide an optical fiber cable and an optical fiber cable manufacturing apparatus, wherein the optical fiber core is not clamped by the outer sheath, thereby preventing increased light loss due to bending of the optical fiber core.

[0013] The means used to solve the problem

[0014] To achieve the above objectives, the optical fiber cable and optical fiber cable manufacturing apparatus disclosed herein, in an optical fiber cable having multiple tensioning members inside the outer sheath, each tensioning member is arranged along the axial direction of the cable core at a position clamping the axial center of the cable core, and applies a warping outward from the axial center of the cable core.

[0015] Specifically, the optical fiber cable disclosed herein is characterized by comprising:

[0016] Cable core with multiple optical fiber cores;

[0017] The outer sheath covering the cable core; and,

[0018] At least two tensioning members have a warping outward from the axial center of the cable core and are disposed inside the outer sheath along the cable core;

[0019] The tensioning members are respectively positioned at the center of the axis where the cable core is clamped by another tensioning member.

[0020] Specifically, the optical fiber cable manufacturing apparatus disclosed herein includes:

[0021] The tensioning member delivery section delivers multiple tensioning members, which are warped outward from the axis center of the cable core, to the vicinity of the cable core; and,

[0022] The outer sheath forming section suppresses the warping of the plurality of tensioning members being delivered and covers the cable core and the plurality of tensioning members located around the cable core with the outer sheath.

[0023] Invention Effects

[0024] According to this disclosure, an optical fiber cable and an optical fiber cable manufacturing apparatus can be realized, in which the optical fiber core is not clamped by the outer sheath, thus preventing increased light loss due to bending of the optical fiber core. Attached Figure Description

[0025] Figure 1 This illustrates an example of the structure of the optical fiber cable according to Embodiment 1.

[0026] Figure 2 This illustrates an example of the structure of the optical fiber cable according to Embodiment 1.

[0027] Figure 3 This illustrates an example of the structure of the optical fiber cable manufacturing apparatus according to Embodiment 2.

[0028] Figure 4 This illustrates an example of the structure of the optical fiber cable manufacturing apparatus according to Embodiment 3.

[0029] Figure 5 This illustrates an example of the structure of the optical fiber cable manufacturing apparatus according to Embodiment 4. Detailed Implementation

[0030] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. However, the present disclosure is not limited to the embodiments shown below. These examples are merely illustrations, and the present disclosure can be implemented in various modified and altered ways based on the knowledge of those skilled in the art. Furthermore, in this specification and the accompanying drawings, the same reference numerals denote identical constituent elements.

[0031] (Implementation Method 1)

[0032] Figure 1 The first embodiment of the present invention is shown in the figure. Figure 1 -a indicates a cross-sectional view of the fiber optic cable 10 before the outer sheath 12 is cut. On the other hand, Figure 1 -b indicates a cross-sectional view of the fiber optic cable 10 after the outer sheath 12 has been cut open. Figure 1 -c indicates Figure 1 -b shows a side view of the fiber optic cable 10.

[0033] like Figure 1 As shown in -a, the fiber optic cable 10 includes: a cable core 11 formed by assembling multiple fiber optic cores 16; an outer sheath 12 covering the cable core 11; and at least two tensioning members 41 disposed inside the outer sheath 12. There are multiple tensioning members 41, each pair of which is disposed at the axial center of the cable core 11 and arranged along the axial direction of the cable core 11. Figure 1In -a, there are two tensioning members 41, but it is not limited to this. Examples of materials for tensioning members 41 include steel, FRP (fiber reinforced plastics), or aramid fibers.

[0034] Each tensioning member 41 is warped outward from the axial center of the cable core 11. The outer sheath 12 inhibits this warping and contains the tensioning members 41 in a manner that allows them to lie along the cable core 11.

[0035] Thus, the tensioning member 41 (e.g., contained in the outer skin 12) Figure 1 The warping of the two tensioning members 41 (shown in -a) that are opposite each other at the axis center of the cable core 11 is suppressed by the outer sheath 12 before the outer sheath 12 is cut, so that there is no visible warping.

[0036] Figure 1 The tensioning member 41 shown has a circular cross-section; examples of different cross-sectional shapes are found in... Figure 2 As shown in the image. Figure 2 -a and Figure 2 -b indicates a cross-sectional view of fiber optic cable 10.

[0037] like Figure 2 As shown in -a, the cross-section of the tensioning member 41 can be quadrilateral.

[0038] In addition, such as Figure 2 As shown in -b, the cross-section of the tensioning member 41 can also be triangular. In this case, the tensioning member 41 can be configured with the vertex of the triangle facing the cable core 11, making it easy for the tensioning member 41 to warp outward from the axial center of the cable core 11. Furthermore, the cross-section of the tensioning member 41 can be arbitrary, and is not limited to, as long as it allows the tensioning member 41 to warp outward from the axial center of the cable core 11.

[0039] To cut the outer sheath 12, the fiber optic cable 10 has two cutting cords 40 on the innermost layer of the outer sheath 12, which is in a direction different from the tensioning member 41 when viewed from the axial center of the cable core 11. The two cutting cords 40 are positioned opposite each other on the axis that clamps the cable core 11. In this case, the two tensioning members 41 are positioned opposite each other on the axis that clamps the cable core 11, and are positioned at the circumferential center connecting the two cutting cords 40.

[0040] When located Figure 1 When the two cutting ropes 40 at the indicated positions are pulled outwards towards the fiber optic cable 10, the outer sheath 12 is cut. At this time, as... Figure 1 -b and Figure 1 As shown in -c, due to the force F generated by the warping of the tensioning member 41, the outer sheath 12 deforms away from the axial center of the cable core 11. Figure 1 -b shows Figure 1 -a's outer edge offset distance G. Due to the warping of the tensioning member 41, such as Figure 1 As shown in -c, the cable core 11 is exposed from the slit. Therefore, the optical fiber core 16 is sandwiched into the slit in the outer sheath 12, thereby reducing the risk of increased optical loss.

[0041] (Implementation Method Two)

[0042] Figure 3 The second embodiment of the present invention is shown in the figure. In this embodiment, an optical fiber cable manufacturing apparatus will be described.

[0043] The fiber optic cable manufacturing equipment 20 is equipped with:

[0044] The tensioning member delivery section 42 delivers multiple tensioning members 41, which are warped outward from the axis center of the cable core 11, to the vicinity of the cable core 11; and,

[0045] The outer sheath forming part 22 suppresses the warping of the multiple tensioning members 41 that are delivered, and covers the cable core 11 and the multiple tensioning members 41 located around the cable core 11 with the outer sheath 12.

[0046] Specifically, the tensioning member delivery section 42, composed of multiple spools, delivers the wound tensioning member 41 from the cable core 11 side to the outer sheath forming section 22, where it is integrated with the outer sheath 12 and covers the cable core 11. At this time, since the tensioning member 41 is wound on the tensioning member delivery section 42, warping is applied to the tensioning member 41. Furthermore, by adjusting the orientation of the pair of tensioning member delivery sections 42, the pair of tensioning member delivery sections 42 are positioned opposite each other, clamping the cable core 11, and the warping directions are different for each pair.

[0047] Here, the tensioning member delivery section 42, in order to cause the tensioning member 41 wound around itself to warp outward from the axis center of the cable core 11 and deliver the tensioning member 41 wound around itself, such as... Figure 3 As shown, it can also be configured so that its own rotation axis is perpendicular to the axis of the cable core 11, and the tensioning member 41 is fed to the outer sheath forming part 22 along the rotation direction of the cable core 11 side of the tensioning member feeding part 42.

[0048] By adopting the structure described above, an optical fiber cable manufacturing apparatus 20 capable of manufacturing the optical fiber cable 10 as described in Embodiment 1 can be realized.

[0049] (Implementation Method 3)

[0050] Figure 4 The third embodiment of the present invention is shown in the figure.

[0051] Compared to the structure described in Embodiment 2, the structure is as follows: a tensioning member deformation section 43, composed of conveyor rollers, is provided between the tensioning member delivery section 42 and the outer sheath forming section 22. The tensioning member 41 delivered from the tensioning member delivery section 42 passes through at least one conveyor roller that serves as the tensioning member deformation section 43. Furthermore, when the tensioning member 41 passes through the tensioning member deformation section 43, the tensioning member 41 is positioned in a direction that warps outward from the axial center of the cable core 11.

[0052] For example, such as Figure 4 As shown, the conveyor roller, which serves as the tensioning member deformation section 43, can also be positioned between the tensioning member delivery section 42 and the cable core 11, and the rotation axis of the conveyor roller is perpendicular to the axis of the cable core 11. Then, the tensioning member delivery section 42 can deliver the tensioning member 41 along the cable core 11 side of the tensioning member deformation section 43 to the outer sheath forming section 22.

[0053] By adopting the structure described above, the optical fiber cable manufacturing apparatus 20 described in Embodiment 2 can be realized, and it is not necessary to reduce the main body diameter of the tension member delivery part 42 in order to apply the necessary warping to the tension member 41. Therefore, long-sized optical fiber cables 10 can be manufactured in one go.

[0054] (Implementation Method 4)

[0055] In the structure described in Embodiment 3, the tensioning member 41 is warped only when passing through the tensioning member deformation portion 43. Therefore, the diameter of the tensioning member deformation portion 43 and the delivery tension of the tensioning member 41 must be controlled to achieve sufficient warping. In this case, there is an increased risk of breakage of the tensioning member 41, and the need to strengthen the peripheral components supporting the tensioning member deformation portion 43.

[0056] Therefore, in Figure 5 The fourth embodiment of the present invention is shown in the figure.

[0057] In addition to the structure shown in Embodiment 3, it also includes a plastic deformation promoting part 44, so that when the tensioning member 41 passes through the tensioning member deformation part 43, it becomes a state in which residual deformation is easily retained.

[0058] Although the specific structure of the plastic deformation promoting part 44 falls within the design scope corresponding to the tensioning member 41 used, for example, if the tensioning member 41 is a composite material such as FRP, a heating method can be used, and if it is steel, a quenching and annealing method can be used.

[0059] By adopting the structure described above, it is easy to retain the deformation generated when the tensioning member 41 passes through the tensioning member deformation section 43, thereby making it easy to obtain the desired warping.

[0060] In addition, the plastic deformation promoting part 44 can be disposed not only in the tension member deformation part 43, but also in the tension member delivery part 42 or between the tension member delivery part 42 and the tension member deformation part 43.

[0061] Industrial applicability

[0062] The optical fiber cable and optical fiber cable manufacturing apparatus disclosed herein are applicable to the information and communication industry.

[0063] Explanation of reference numerals in the attached figures

[0064] 10: Fiber optic cables

[0065] 11: Cable core

[0066] 12: Outer skin

[0067] 16: Fiber optic core wire

[0068] 20: Fiber optic cable manufacturing equipment

[0069] 22: Outer skin forming part

[0070] 40: Cut the rope

[0071] 41: Tensioning component

[0072] 42: Tensioning component delivery section

[0073] 43: Deformation section of tensioning member

[0074] 44: Plastic deformation promoting section.

Claims

1. An optical fiber cable, characterized in that, include: Cable core with multiple optical fiber cores; The outer sheath covering the cable core; The two cut ropes located in the innermost layer of the outer skin, and, At least two tensioning members have a warping outward from the axial center of the cable core and are disposed inside the outer sheath along the cable core; The tensioning members are respectively positioned at the center of the axis where the cable core is clamped by another tensioning member; When the outer sheath is cut, the tensioning member bends outward from the axis center of the cable core, exposing the cable core; When the outer sheath is cut by the two cutting ropes, the cable core is exposed from the tear in the outer sheath due to the warping of the tensioning member.

2. An optical fiber cable manufacturing apparatus for manufacturing the optical fiber cable of claim 1, comprising: The tensioning member delivery section delivers multiple tensioning members, which are warped outward from the axis center of the cable core, to the vicinity of the cable core; and, The outer sheath forming section suppresses the warping of the plurality of tensioning members being delivered and covers the cable core and the plurality of tensioning members located around the cable core with the outer sheath.

3. The optical fiber cable manufacturing apparatus according to claim 2, characterized in that, The tensioning member delivery section has a plurality of spools respectively arranged around the cable core, which deliver the tensioning member wound on itself from the cable core side to the outer sheath forming section.

4. The optical fiber cable manufacturing apparatus according to claim 2, characterized in that, It also includes: a tensioning member deformation section to enhance the warping of the tensioning member outward from the axial center of the cable core; The tensioning member delivery section delivers the tensioning member to the outer skin forming section via the tensioning member deformation section.

5. The optical fiber cable manufacturing apparatus according to claim 4, characterized in that, The deformable part of the tensioning member is a conveyor roller whose rotating axis is perpendicular to the axis of the cable core.

6. The optical fiber cable manufacturing apparatus according to claim 4 or 5, characterized in that, It also includes: a plastic deformation promoting section, which prevents the tensioning member from warping outward from the axial center of the cable core.

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