Optical fiber cable

Abstract

To provide an optical fiber cable attaining compatibility between fastness properties and disassembling characteristics.SOLUTION: An optical fiber cable comprises a cable core including a plurality of coated optical fibers, a sheath provided on a periphery of the cable core, a reinforcement sheet embedded in the sheath, and tension members embedded in the sheath. The reinforcement sheet is disposed in such a manner that a clearance is formed at a part in a circumferential direction of the cable core. The tension members are disposed in such a manner that parts of the tension members are overlapped on a line segment connecting a first end and a second end in a circumferential direction of the reinforcement sheet.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to fiber optic cables. [Background technology]

[0002] Patent document 1 describes an optical fiber cable comprising a unit housing multiple optical fiber cores, an inner sheath housing the unit, a reinforcing sheet arranged around the inner sheath, and an outer sheath arranged around the reinforcing sheet. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-106568 A Summary of the Invention [Problem to be solved by the invention]

[0004] As disclosed in Patent Document 1, an optical fiber cable having a reinforcing sheet disposed around the inner sheath has excellent robustness.

[0005] On the other hand, there is room for improvement in the ease of disassembly of the optical fiber cable as disclosed in Patent Document 1.

[0006] An object of the present disclosure is to provide an optical fiber cable that is both robust and easy to dismantle. [Means for solving the problem]

[0007] An optical fiber cable according to one aspect of the present disclosure includes: a cable core including a plurality of optical fiber cores; an outer sheath provided around the cable core; A reinforcing sheet embedded in the outer cover; A tension member embedded in the outer cover, The reinforcing sheet is disposed so as to form a gap in a part of the circumferential direction of the cable core, The strength member is arranged so that a portion of the strength member overlaps a line segment connecting a first end portion and a second end portion in the circumferential direction of the reinforcing sheet. Effect of the Invention

[0008] According to the present disclosure, an optical fiber cable that is both robust and easy to dismantle can be provided. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a cross-sectional view of an optical fiber cable according to the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Description of the embodiments of the present disclosure First, the embodiments of the present disclosure will be listed and described. (1) An optical fiber cable according to one embodiment of the present disclosure comprises: a cable core including a plurality of optical fiber cores; an outer sheath provided around the cable core; A reinforcing sheet embedded in the outer cover; A tension member embedded in the outer cover, The reinforcing sheet is disposed so as to form a gap in a part of the circumferential direction of the cable core, The strength member is arranged so that a portion of the strength member overlaps a line segment connecting a first end portion and a second end portion in the circumferential direction of the reinforcing sheet. According to the optical fiber cable described above, by removing the tension members, the optical fiber cable can be easily dismantled through the gaps in the reinforcing sheet. In addition, since the tension members are provided in the circumferential gaps in the reinforcing sheet, the robustness of the optical fiber cable is improved in the circumferential direction. This provides an optical fiber cable that is both robust and easy to dismantle.

[0011] (2) In the optical fiber cable according to (1) above, The tension member may be one or more, and the total length of the diameters of the tension members may be greater than the distance of the line segment connecting the first end and the second end. The tension member is one or more, and the total length of the diameters of the tension members is greater than the distance of the line segment connecting the first end and the second end, so that the tension members are easily arranged to fill the gaps in the reinforcing sheet, thereby improving the robustness of the optical fiber cable in the circumferential direction.

[0012] (3) In the optical fiber cable according to (1) or (2) above, The tension members may be provided in a plurality. According to the above configuration, since a plurality of strength members are provided, the optical fiber cable is configured to close the gaps in the reinforcing sheet with the plurality of strength members, which reduces the required radial thickness of the outer jacket compared to when a single strength member is used to close the gaps, thereby enabling the optical fiber cable to be made smaller in diameter.

[0013] (4) In the optical fiber cable according to any one of (1) to (3) above, A tear cord may be provided between the cable core and the outer jacket. A tear string is provided between the cable core and the jacket, improving the ease of dismantling the optical fiber cable.

[0014] (5) In the optical fiber cable according to any one of (1) to (4) above, The diameter of the tension member may be 1.2 mm or more and 2.4 mm or less. By setting the diameter of the tensile member to be 1.2 mm or more and 2.4 mm or less, it becomes easier to achieve both robustness of the optical fiber cable and a smaller diameter of the optical fiber cable.

[0015] DETAILED DESCRIPTION OF EMBODIMENTS OF THE DISCLOSURE Specific examples of the optical fiber unit and the optical fiber cable according to the embodiment of the present disclosure will be described below with reference to the drawings. Note that 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 equivalent to the claims.

[0016] Fig. 1 is a cross-sectional view of an optical fiber cable 1. As illustrated in Fig. 1, the optical fiber cable 1 includes a cable core 10, an outer jacket 20, a reinforcing sheet 30, a tensile member 40, and a tear string 50.

[0017] The cable core 10 includes a plurality of optical fiber cores 11. The optical fiber core 11 of the present embodiment constitutes an optical fiber ribbon 12 in which 12 optical fiber cores are connected in parallel. The cable core 10 is constituted by an assembly of five units formed by bundling a plurality of optical fiber ribbons. In the optical fiber ribbon 12, adjacent optical fiber cores 11 may be intermittently connected to each other at a predetermined interval in the longitudinal direction of the optical fiber ribbon 12. The optical fiber cores 11 may each be in the form of a single core without constituting an optical fiber ribbon. The optical fiber core 11 has a glass fiber having a core and a clad, and a resin layer covering the glass fiber. The diameter of the glass fiber is usually about 125 μm. The diameter of the optical fiber core 11 is, for example, 180 μm or more and 220 μm or less, and is 200 μm in this example.

[0018] The outer jacket 20 is provided around the cable core 10 to cover the cable core 10. The outer jacket 20 can be made of, for example, polyethylene resin, flame-retardant polyethylene resin, polyvinyl chloride resin, or the like.

[0019] The reinforcing sheet 30 is embedded in the jacket 20. The reinforcing sheet 30 is disposed at a middle position in the thickness of the layer of the jacket 20. The reinforcing sheet 30 is disposed in a C-shape in cross section so that a gap is formed in a part of the circumferential direction of the cable core 10. The reinforcing sheet 30 is formed of, for example, steel or hard plastic. The thickness of the reinforcing sheet 30 may be 0.5 mm or more and 1.5 mm or less. In addition, the distance of the line segment L connecting the first end A1 and the second end A2 may be 2.0 mm or more and 4.6 mm or less. In this embodiment, the distance of the line segment L is 3.4 mm.

[0020] The tension body 40 is embedded in the jacket 20 along the cable core 10. The tension body 40 is made of, for example, steel or hard plastic. The reinforcing sheet 30 and the tension body 40 may be adjusted in thickness or material in order to uniformize the bending rigidity in the circumferential direction of the optical fiber cable 1. For example, the reinforcing sheet 30 and the tension body 40 may be made of the same material in order to uniformize the bending rigidity in the circumferential direction of the optical fiber cable 1. The diameter D of the tension body 40 is preferably 1.2 mm or more and 2.4 mm or less. In the example of this embodiment, the tension body 40 is made of steel, and the diameter D of the tension body 40 is 1.8 mm. It is preferable that the reinforcing sheet 30 and the tension body 40 are on the same circumference, but they do not necessarily have to have the same thickness. For example, the diameter of the tension body 40 may be larger than the thickness of the reinforcing sheet 30.

[0021] A plurality of the strength members 40 may be provided. In the optical fiber cable 1 of the present embodiment, two strength members 40 are provided side by side in the circumferential direction of the cable. It is desirable that the strength members 40 are arranged together in only one place in the jacket 20. This can reduce the bending anisotropy of the optical fiber cable 1, thereby improving the workability of the optical fiber cable 1.

[0022] The tension members 40 are arranged so as to be sandwiched in gaps formed by the reinforcing sheet 30. Specifically, the tension members 40 are arranged so that a portion of the tension members 40 overlaps a line segment L connecting a first end A1 and a second end A2 in the cable circumferential direction of the reinforcing sheet 30. The reinforcing sheet 30 and the tension members 40 may be arranged on the same circumference in order to make the bending rigidity of the optical fiber cable 1 in the circumferential direction uniform.

[0023] The total length of the diameter D of the reinforcing members 40 is desirably greater than the distance of the line segment L connecting the first end A1 and the second end A2. In this embodiment, the diameter D of the reinforcing members 40 is 1.8 mm, and since two reinforcing members 40 are provided, the total length of the diameter D of the reinforcing members 40 is 3.6 mm. In addition, the distance of the line segment L connecting the first end A1 and the second end A2 is 3.4 mm. In this case, the reinforcing sheet 30 and the reinforcing members can be arranged so that the gaps in the reinforcing sheet 30 are filled by the reinforcing members 40.

[0024] The tear cord 50 is disposed between the cable core 10 and the outer jacket 20. For example, one tear cord 50 is provided on the inner circumferential surface of the outer jacket 20 so as to sandwich the center of the cable core 10. The tear cord 50 is made of a resin material such as nylon or polyester.

[0025] In an optical fiber cable in which a reinforcing sheet is disposed so as to surround the entire circumference of the cable core, the robustness of the optical fiber cable can be ensured, but dismantling the optical fiber cable is likely to be troublesome. In addition, when a strength member is provided in the cable core, the diameter of the cable core is likely to increase, and when a strength member is embedded in the jacket, the thickness of the jacket is likely to increase, so that the outer diameter of the optical fiber cable is also likely to increase.

[0026] According to the above optical fiber cable 1, by removing the tensile members 40, the optical fiber cable 1 can be easily dismantled from the gaps in the reinforcing sheet 30. Furthermore, since the tensile members 40 are provided in the circumferential gaps in the reinforcing sheet 30, the robustness of the optical fiber cable 1 is improved in the circumferential direction. This provides an optical fiber cable 1 that is both robust and easy to dismantle. Furthermore, since the reinforcing sheet 30 can ensure a certain degree of cable rigidity, the diameter of the tensile members 40 can be made relatively small. This provides an optical fiber cable 1 that is robust and easy to dismantle, while having a small diameter.

[0027] Although the present disclosure has been described in detail and with reference to specific embodiments, it is clear 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. [Explanation of symbols]

[0028] 1. Fiber optic cable 10 Cable Core 11 Optical fiber core 12 Optical fiber ribbon 20 Outer cover 30 Reinforcement sheet 40 Tensile strength body 50 Rip Cord A1 First end A2 second end L line segment

Claims

1. a cable core including a plurality of optical fiber cores; an outer sheath provided around the cable core; A reinforcing sheet embedded in the outer cover; A tension member embedded in the outer cover, The reinforcing sheet is disposed so as to form a gap in a part of the circumferential direction of the cable core, The tension member is arranged so that a portion of the tension member overlaps a line segment connecting a first end portion and a second end portion in the circumferential direction of the reinforcing sheet. Fiber optic cable.

2. The tension member is provided as one or more tension members, and a total length of diameters of the tension members is greater than a distance of the line segment connecting the first end and the second end.

2. The optical fiber cable according to claim 1.

3. The tension members are provided in a plurality. The optical fiber cable according to claim 1 or 2.

4. A tear cord is provided between the cable core and the jacket. The optical fiber cable according to claim 1 or 2.

5. The diameter of the tension member is 1.2 mm or more and 2.4 mm or less. The optical fiber cable according to claim 1 or 2.

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