Optical cable

Abstract

The present application aims to provide an optical cable in which a tear-off string is exposed first when a sheath having three or more tensile bodies is cut with a knife or the like. To achieve the above object, the optical cable (1) of the present application includes: an optical fiber core wire (14); a sheath (11) that covers the optical fiber core wire (14); three or more tensile bodies (12) that are arranged inside the sheath (11) along the long axis of the optical fiber core wire (14); and a tear-off string (13) in which, in a portion of the cross section perpendicular to the long axis direction of the sheath (11), a portion of the outer circumference is located outward of the outer side tangent line (17) of the outer circumference of the three or more tensile bodies (12), and in the cross section perpendicular to the long axis direction of the sheath (11), a portion of the outer circumference is in contact with or located inward of the inner circumference of the sheath (11).

Description

Technical Field

[0001] The present invention relates to an optical cable having a tear cord disposed inside the optical cable for tearing. Background Technology

[0002] Currently, optical fibers are used in communication networks used to provide multimedia services. Specifically, optical cables with an outer sheath applied to bundled optical fiber cores are used. Conventionally, optical cables have slotted rods, which house the optical fiber cores within slots, but slotless optical cables without slotted rods are used for the purpose of reducing diameter (see, for example, Patent Document 1).

[0003] Figure 1 1 is the cross-section of the slotless optical cable 1, 11 is the outer sheath, 12 is the tensile strength body, 13 is the rope for tearing the outer sheath (hereinafter referred to as the "tear rope"), and 14 is the optical fiber core.

[0004] Tension resisting body 12 is embedded in the outer sheath 11 parallel to the long axis of the optical cable 1. Tension resisting body 12 protects the optical fiber core 14 from tension acting on the long axis of the optical cable 1, and is made of components such as steel wire or fiber-reinforced plastic, and has a thickness that can provide sufficient rigidity. Sometimes the tension resisting body 12 is composed of multiple pieces (for example, see Patent Document 2).

[0005] A tearing rope 13 is also embedded in the outer sheath 11 to easily tear open the outer sheath and remove the optical fiber core 14 inside the optical cable. By cutting open the outer sheath with a knife or the like, the tearing rope 13 can be exposed and removed. Existing technical documents

[0006] Patent Document 1: Japanese Patent No. 4619424 (NTT) Patent Document 2: Japanese Patent Publication No. 2015-166806 (NTT)

[0007] Tension resisting element 12 is essential for protecting optical cable 1 and optical fiber core 14. However, besides hindering the reduction of cable diameter due to its thickness, if tension resisting element 12 is placed in an asymmetrical position on optical cable 1, it becomes a major cause of bending directionality, thereby reducing the cable's maneuverability. To address this, as shown in Patent Document 2, by arranging multiple tension resisting elements in symmetrical positions, the diameter of each tension resisting element can be reduced, and the bending directionality can be mitigated.

[0008] On the other hand, in cases where there are multiple tensile strength elements 12, as in Patent Document 2, when cutting the outer sheath 11 with a knife or similar tool, the tensile strength elements 12 come into contact with the tearing rope 13 before reaching it, making it difficult to remove the tearing rope 13. In this situation, the tearing rope 13 cannot be used when tearing the outer sheath 11, and a sharp tool must be directly inserted into the housing of the optical fiber core 14 to tear it. In addition to the possibility of damaging the optical fiber core 14, the tearing operation takes a long time. Summary of the Invention

[0009] In order to solve the aforementioned problem, the present invention aims to provide an optical cable in which, when the outer sheath having three or more tensile elements is cut with a knife or the like, the rope is torn open before the tensile elements are exposed.

[0010] To achieve the above objectives, the optical cable of the present invention has a tear cord arranged along the long axis direction, which is located further outward than the tensile body inside the outer sheath of the cable.

[0011] Specifically, the optical cable of the present invention comprises: Fiber optic core wire; Outer sheath, covering the optical fiber core; Three or more tensile strength elements are arranged inside the outer sheath along the long axis of the optical fiber core; and When the rope is torn, in a section perpendicular to the long axis of the outer skin, a portion of the outer periphery is located further outward than the outer tangent of the outer periphery of the three or more tensile bodies. In a section perpendicular to the long axis of the outer skin, a portion of the outer periphery is in contact with the inner periphery of the outer skin or is located further inward than the inner periphery of the outer skin.

[0012] For example, in the optical cable of the present invention, the outer tangent of the three or more tensile bodies is located further outward than the inner periphery of the outer sheath.

[0013] For example, in the optical cable of the present invention, the tear cord is composed of multiple cords.

[0014] For example, in the optical cable of the present invention, the tearing cord is a structure in which the multiple cords are twisted together.

[0015] For example, in the optical cable of the present invention, the tearing cord is a structure in which the multiple cords are woven together.

[0016] For example, in the optical cable of the present invention, the plurality of ropes in the tear rope are bonded together.

[0017] For example, in the optical cable of the present invention, at least one of the tearing ropes is configured as a straight shape, and at least one rope is configured as a wave shape that repeatedly contacts and separates from the rope configured as the straight shape (hereinafter referred to as "straight shape rope"). The portion of the rope configured as the wave shape that contacts the straight shape rope is bonded or fused and is located inside the outer tangent, and the portion that separates from the straight shape rope is located outside the outer tangent.

[0018] For example, in the optical cable of the present invention, the outer sheath of the portion where the tear cord is provided is thinner than the outer sheath of the portion where the tear cord is not provided.

[0019] Furthermore, the inventions described above can be combined in combination as much as possible.

[0020] According to the present invention, an optical cable is provided in which, when the outer sheath having three or more tensile elements is cut with a knife or the like, the rope is torn open before the tensile elements are exposed. Attached Figure Description

[0021] Figure 1 This is an example of the cross-section of a slotless optical cable. Figure 2 This is an example of the cross-section of the grooveless optical cable of the present invention. Figure 3 This is an example of a cross-section near the tear rope of the optical cable of the present invention. Figure 4 This is an example of a cross-section near the tear rope of the optical cable of the present invention. Figure 5 This is an example of a cross-section near the tear rope of the optical cable of the present invention. Figure 6 This is an example of a cross-section along the long axis of the optical cable of the present invention. Figure 7 This is an example of the cross-section of the optical cable of the present invention. Figure 8 This is an example of the cross-section of the optical cable of the present invention. Figure 9 This is an example of the cross-section of the optical cable of the present invention. Detailed Implementation

[0022] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments shown below. These embodiments are merely illustrative, and the present invention can be implemented in various modifications and alterations 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.

[0023] (Implementation Method) Figure 2This diagram shows an example of a cross-section of an optical cable perpendicular to its long axis, according to an embodiment of the present invention. 1 is the optical cable, 11 is the outer sheath, 12 is the tensile strength body, 13 is the tear cord, 14 is the optical fiber core, and 17 is the outer tangent.

[0024] The optical cable 1 has an outer sheath 11, a tensile body 12, a tear rope 13, and an optical fiber core wire 14.

[0025] The outer sheath 11 covers one or more optical fiber cores 14. The outer sheath 11 can directly cover the optical fiber cores 14, or it can cover each optical fiber core 14 covered by a sheath.

[0026] The outer sheath 11 has three or more tensile strength members 12 inside, running along the long axis of the optical fiber core 14. The tensile strength members 12 may also be made of components such as steel wire or fiber-reinforced plastic. In this embodiment, the interior of the outer sheath 11 refers to the... Figure 2 The area between the inner and outer circumferences of the outer sheath 11 in the cross-section of the optical cable 1 shown.

[0027] In this embodiment, in a cross-section perpendicular to the long axis of the outer skin 11, the outer periphery of the rounded polygon is designated as the outer tangent 17. This rounded polygon is formed by connecting the outer peripheries of three or more tension bodies 12 through the outermost common tangent of the outer peripheries of adjacent tension bodies 12. Figure 2 The example shows the outer tangent 17 of a rounded quadrilateral, but is not limited to this.

[0028] The outer tangent 17 is preferably located further outward than the inner circumference of the outer sheath 11 in a cross section perpendicular to the long axis direction of the outer sheath 11. As a result, when the outer sheath 11 is cut open with a tool or the like, the tensile strength 12 is exposed before the optical fiber core 14, thus protecting the optical fiber core 14.

[0029] In at least a portion of the cross-section perpendicular to the long axis of the outer skin 11, a portion of the outer periphery of the tear rope 13 is located further outward than the outer tangent 17. This is considered requirement 1. When a portion of the outer periphery of the tear rope 13 is located further outward than the outer tangent 17 in all cross-sections perpendicular to the long axis of the outer skin 11, the tear rope 13 can be exposed by cutting the outer skin 11 from the tear rope 13 side at any cross-section using a knife or the like. On the other hand, when a portion of the outer periphery of the tear rope 13 is located further outward than the outer tangent 17 only in a portion of the cross-section perpendicular to the long axis of the outer skin 11, in order to expose the tear rope 13, the outer skin 11 needs to be cut from the tear rope 13 side at the cross-section where a portion of the outer periphery of the tear rope 13 is located further outward than the outer tangent 17 using a knife or the like.

[0030] Furthermore, in a cross-section perpendicular to the long axis of the outer sheath 11, a portion of the outer periphery of the tearing cord 13 contacts the inner periphery of the outer sheath 11 or is located further inward than the inner periphery of the outer sheath 11. This is considered requirement 2. Preferably, in the entire cross-section perpendicular to the long axis of the outer sheath 11, a portion of the outer periphery of the tearing cord 13 contacts the inner periphery of the outer sheath 11 or is located further inward than the inner periphery of the outer sheath 11. Thus, by pulling the tearing cord 13, the entire outer sheath 11 can be neatly torn apart, exposing the optical fiber core 14. Furthermore, as long as the entire outer sheath 11 can be neatly torn apart, the tearing cord 13 can also be located further outward than the inner periphery of the outer sheath 11.

[0031] The tearing of rope 13 preferably occurs in at least a portion of a cross-section perpendicular to the long axis of the outer sheath 11, satisfying requirements 1 and 2 above. For example, as... Figure 2 As shown, the tear cord 13 can also be located between the two tensile bodies 12, thereby satisfying both requirements 1 and 2. The tear cord 13 can also satisfy requirements 1 and 2 respectively in different cross sections perpendicular to the long axis direction of the outer skin 11. Furthermore, the tear cord 13 does not necessarily need to be arranged in two locations, but can be arranged in three or more locations.

[0032] Markings indicating the positions where the outer skin 11 can be cut with a knife or the like can also be provided on the surface of the outer skin 11. For example, if a portion of the outer periphery of the tear rope 13 is located further outward than the outer tangent 17 in a section perpendicular to the long axis of the outer skin 11, markings can be provided on the surface of the outer skin 11 in the section where the outer periphery of the tear rope 13 is located further outward than the outer tangent 17, thus exposing the tear rope 13 more reliably.

[0033] use Figures 3 to 6 The structure of the tear rope 13 of the optical cable 1 will be explained.

[0034] Figures 3 to 5 This is an example of a cross-section near the tear rope 13 of optical cable 1. Figures 3 to 5 This only indicates a portion of the outer sheath 11 of two tension elements 12 and a tear rope 13 located between the two tension elements 12 in a cross-section perpendicular to the long axis of the optical cable 1. 15 is the outermost common tangent line in the common tangent lines drawn between adjacent tension elements 12, and is a portion of the outer tangent line 17. Hereinafter, in Figures 3 to 5 In the illustration, the outer tangent 17 will be used as the common tangent 15 for the purpose of using the torn rope 13 and the two tension-resistant bodies 12.

[0035] The shape of the torn rope 13 is arbitrary. For example, it can also be configured as follows: the cross-section is... Figure 3 The circle or shown Figure 4The rectangle shown has, in at least a portion of a cross section perpendicular to the long axis of the outer skin 11, a portion of its outer periphery located further outward than the common tangent 15, and another portion of its outer periphery contacting or located further inward than the inner periphery of the outer skin 11.

[0036] like Figure 5 As shown, the tearing rope 13 can also be composed of multiple ropes. In this case, it can also be configured such that a portion of the outer periphery of at least one of the multiple ropes constituting the tearing rope 13 is located further outward than the common tangent 15, and at least a portion of the outer periphery of any one of the multiple ropes is in contact with or located further inward than the inner periphery of the outer sheath 11.

[0037] The tearing rope 13 can also be a structure in which multiple ropes are twisted together. The tearing rope 13 can also be a structure in which multiple ropes are woven together. The multiple ropes in the tearing rope 13 can also be glued together. Based on these structures, by removing at least one of the multiple tearing ropes 13, the other tearing ropes 13 can be removed simultaneously.

[0038] Figure 6 This represents an example of a cross-section along the long axis of optical cable 1.

[0039] In the tearing of rope 13, at least one rope 13a is configured in a straight shape, and at least one rope 13b is configured in a wavy shape that repeatedly contacts and separates from the straight rope 13a (hereinafter referred to as "straight rope 13a"). The portion of the wavy rope 13b (hereinafter referred to as "wavy rope 13b") that contacts the straight rope 13a is bonded or fused and is located closer to the inner side than the outer tangent 17, while the portion that separates from the straight rope 13a is located further outward than the outer tangent 17. Preferably, in the entire cross-section perpendicular to the long axis direction of the outer skin 11, a portion of the outer periphery of the straight rope 13a contacts the inner periphery of the outer skin 11 or is located closer to the inner periphery than the inner periphery of the outer skin 11. Preferably, the wavy rope 13b takes the radial direction of the outer skin 11 as the amplitude direction.

[0040] The tearing cord 13, composed of a straight cord 13a and a wavy cord 13b, can be formed from two thin cords 13. Furthermore, the wavy cord 13b is positioned on the outside of the outer sheath 11 for easy pulling, thus eliminating the need to thin the outer sheath of the portion containing the tearing cord 13 and maintaining the strength of the optical cable 1. When the outer sheath 11 is cut using a tool or similar tool, a portion of the wavy cord 13b can be exposed before the tensile body 12. If the exposed wavy cord 13b is pulled out, the bonded or fused straight cord 13a is simultaneously pulled out, thus dividing the outer sheath 11 and allowing easy removal of the optical fiber 14.

[0041] Figures 7 to 9 An example of the cross-section of optical cable 1 according to an embodiment of the present invention.

[0042] The thickness of the outer skin 11 with the tear cord 13 can also be thinner than the thickness of the outer skin without the tear cord 13. For example, as... Figure 7 As shown, the inner circumference of the outer skin 11 can also be elliptical, with a tearing rope 13 positioned at the apex of the ellipse along its major axis. Figure 8 As shown, a protrusion can also be provided on a portion of the inner circumference of the outer skin 11, and a tearing rope 13 can be disposed at the top of the protrusion. Figure 9 As shown, protrusions and flat sections with low curvature can also be provided on the inner circumference of the outer skin 11, with a tearing rope 13 disposed at the top of the protrusion. Alternatively, the shape of the outer circumference of the outer skin 11 can be changed without altering the shape of the inner circumference. Furthermore, both the shape of the inner circumference and the shape of the outer circumference of the outer skin 11 can be changed.

[0043] Furthermore, even if the shape of the inner or outer periphery of the outer skin 11 is changed, the structure and configuration of the tensile body 12 and the tear rope 13 remain the same as described above.

[0044] By changing the shape of the inner or outer periphery of the outer sheath 11, the optical fiber 14 can be easily removed without changing the shape of the tearing rope 13.

[0045] According to the optical cable of the present invention, when the outer sheath 11 is cut with a knife or the like, the tearing rope 13 is exposed before the tensile body 12. Industrial applicability

[0046] The optical cable of this invention can be applied to the information and communication industry. Explanation of reference numerals in the attached figures

[0047] 1: Optical fiber cable 11: Outer skin 12: Tension body 13: Tear the rope 14: Fiber optic core 15: Common tangent 16: Adhesive part 17: Outer tangent

Claims

1. An optical cable, characterized in that, have: Fiber optic core; Outer sheath, covering the optical fiber core; Three or more tensile strength elements are arranged inside the outer sheath along the long axis of the optical fiber core; and Multiple tear-off ropes are arranged inside the outer sheath along the long axis of the optical fiber core. Each of the plurality of tearing ropes comprises: a straight rope configured in a straight shape; and a wavy rope configured to repeatedly contact and separate from the straight rope. A portion of the outer periphery of the straight rope is in contact with or located more inwardly than the inner periphery of the outer sheath. The portion of the wavy rope that contacts the straight rope and the straight rope are located closer to the inner side than the outer tangent of the outer periphery of the three or more tension bodies. The portion of the wavy rope that separates from the straight rope is located further outward than the outer tangent in a cross-section perpendicular to the long axis of the optical fiber core.

2. The optical cable according to claim 1, characterized in that, The outer tangent of the three or more tensile elements is located further outward than the inner periphery of the outer skin.

3. The optical cable according to claim 1, characterized in that, The tearing rope is composed of multiple ropes, including the straight rope and the wavy rope.

4. The optical cable according to claim 3, characterized in that, The tearing rope is a structure in which multiple ropes are twisted together.

5. The optical cable according to claim 3, characterized in that, The tearing rope is a structure in which multiple ropes are interwoven.

6. The optical cable according to claim 3, characterized in that, The multiple ropes in the torn rope are glued together.

7. The optical cable according to any one of claims 1 to 6, characterized in that, The outer skin with the tear cord is thinner than the outer skin without the tear cord.

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