Optical cable

Abstract

To provide an optical cable capable of protecting a coated optical fiber against living things such as cicadas and rats.SOLUTION: An optical cable 1 comprises: a coated optical fiber 2; a pair of tension members 4 disposed on both lateral sides of the coated optical fiber 2; protection members 5 that are disposed on both sides of an orthogonal direction crossing at a right angle with both of an arrangement direction of the pair of tension members 4 and a lengthwise direction of the cable, in the coated optical fiber 2 and the pair of tension members 4; and a sheath 7 covering the coated optical fiber 2, the pair of tension members 4, and the protection members 5. The protection members 5 are fixed to each of the pair of tension members 4.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an optical cable.

Background Art

[0002] Patent Document 1 discloses an optical fiber cable in which an optical fiber core wire, a pair of tension members, and a pair of protective walls are covered with an outer cable sheath. The pair of tension members are arranged on both sides of the optical fiber core wire, and the pair of protective walls are vertically attached to the optical fiber core wire on both sides of the optical fiber core wire on the side where the tension members are not arranged. The pair of protective walls serve to protect the optical fiber core wire from the ovipositor of a cicada or the teeth of an animal such as a rat or a squirrel when the ovipositor of a cicada pierces the optical fiber cable or an animal bites the optical fiber cable.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the optical fiber cable described in Patent Document 1, there is a possibility that the ovipositor of a cicada or the teeth of a rat may pass between the tension member and the protective wall and reach the optical fiber core wire, and there is room for improvement from the viewpoint of protecting the optical fiber core wire.

[0005] The present invention has been made in view of the above circumstances, and an object thereof is to provide an optical cable capable of protecting an optical fiber core wire from organisms such as cicadas and rats.

Means for Solving the Problems

[0006] To achieve the above object, the present invention provides an optical cable comprising an optical fiber core, a pair of tension members disposed on both sides of the optical fiber core, protective members disposed on both sides in a direction orthogonal to both the arrangement direction of the pair of tension members and the cable longitudinal direction in the optical fiber core and the pair of tension members, and an outer jacket covering the optical fiber core, the pair of tension members, and the protective members, wherein the protective members are fixed to the respective ones of the pair of tension members.

Advantages of the Invention

[0007] According to the present invention, it is possible to provide an optical cable capable of protecting the optical fiber core from organisms such as cicadas and mice.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Embodiments for Carrying Out the Invention

[0009] [First Embodiment] The first embodiment of the present invention will be described with reference to FIGS. 1 to 3. Note that the embodiments described below are shown as preferred specific examples for carrying out the present invention, and although there are parts that specifically illustrate various technically preferable technical matters, the technical scope of the present invention is not limited to this specific aspect.

[0010] FIG. 1 is a perspective view of the optical cable 1 in this embodiment. FIG. 2 is a cross-sectional view of the optical cable 1 in this embodiment.

[0011] The optical cable 1 of this embodiment can be installed, for example, inside a station building such as a subway, used as wiring within or between data centers, or used as a so-called drop cable. Generally, in an optical cable, damage from organisms such as insects, rodents, and birds can occur. For example, when the optical cable is arranged outdoors, there is a concern that cicadas may pierce the optical cable with their ovipositors or crows may peck at the optical cable, and when the optical cable is arranged inside a station building such as a subway, there is a concern that rats may bite the optical cable. Therefore, the optical cable 1 of this embodiment is devised to more reliably protect the optical fiber core wire 2 in the optical cable 1 from the above-mentioned damage.

[0012] The optical cable 1 of this embodiment includes an optical fiber core wire 2, a water-absorbing tape 3, a pair of tension members 4, a pair of protective members 5, an internal resin 6, and an outer sheath 7. Hereinafter, the longitudinal direction of the optical cable 1 is referred to as the cable longitudinal direction, the width direction of the optical cable 1 is referred to as the cable width direction, and the thickness direction of the optical cable 1 is simply referred to as the cable thickness direction. In this embodiment, the cable longitudinal direction, the cable width direction, and the thickness direction are perpendicular to each other.

[0013] The optical fiber core wire 2 is a so-called tape core wire and has four optical fiber strands 21 arranged in the cable width direction and a tape coating 22 that collectively covers the four optical fiber strands 21. Although detailed illustration is omitted, each optical fiber strand 21 has a core made of quartz glass or the like with a high refractive index, a cladding made of quartz glass or the like with a low refractive index that covers the outer periphery of the core, and a core coating made of resin that covers the outer periphery of the cladding. The tape coating 22 is made of, for example, an ultraviolet curable resin and embeds the four optical fiber strands 21 inside. The optical fiber core wire 2 is not particularly limited, but is used for communication and can be, for example, a multimode optical fiber or a single mode optical fiber.

[0014] The water-absorbing tapes 3 are arranged on both sides of the optical fiber core wire 2 in the cable thickness direction. Each water-absorbing tape 3 is vertically attached to the optical fiber core wire 2. The water-absorbing tape 3 is wide in the cable width direction and faces the optical fiber core wire 2 in the cable thickness direction. The water-absorbing tape 3 has the role of ensuring the waterproofness of the optical fiber core wire 2.

[0015] The pair of tension members 4 are located on opposite sides in the cable width direction with the optical fiber core wire 2 interposed therebetween. The pair of tension members 4 are vertically attached to the optical fiber core wire 2 and are arranged at a predetermined interval in the cable width direction with respect to the optical fiber. The tension member 4 is used to resist the tensile force acting on the optical cable 1 and is composed of a highly rigid wire material such as a single wire or a stranded steel wire, fiber reinforced plastic (FRP), aramid fiber, or Kevlar (registered trademark) fiber.

[0016] In this embodiment, the tension member 4 has a circular cross-sectional shape orthogonal to the longitudinal direction of the cable. The diameter of the tension member 4 can be, for example, 0.4 mm or more and 1.2 mm or less. The diameter of the tension member 4 is larger than the thickness of the optical fiber core 2. In the cable thickness direction, the optical fiber core 2 is arranged so as to be within the region between the end positions of both ends of each tension member 4. And the pair of tension members 4 surrounds the optical fiber core 2 together with the pair of protective members 5.

[0017] The pair of protective members 5 are arranged so as to cover the optical fiber core 2 and the pair of tension members 4 from both sides in the cable thickness direction. The protective member 5 is formed, for example, by forming a metal, an alloy, etc. into a tape shape. The protective member 5 can be constituted by, for example, a laminated tape made of stainless steel, iron, etc. The protective member 5 is wide in the cable width direction and is longitudinally attached to the optical fiber core 2 and the pair of tension members 4. In this embodiment, the protective member 5 is formed flat in the cable longitudinal direction. In this embodiment, the width of the protective member 5 satisfies 4 mm or more and 7 mm or less. Also, the thickness of the metal portion of the protective member 5 can be 0.05 mm or more and 0.20 mm or less.

[0018] Each protective member 5 is fixed to a pair of tension members 4. In the present embodiment, each protective member 5 and the pair of tension members 4 are adhered via an adhesive 11. In the present embodiment, the adhesive 11 is a hot melt adhesive that melts when heated. In the present embodiment, the adhesive 11 is provided on both surfaces of each protective member 5 and on the entire circumferential surface of each tension member 4. Further, the adhesive 11 is provided over substantially the entire length of the optical cable 1 in the longitudinal direction of the cable. Then, both end portions of the protective member 5 in the cable width direction and end portions of the pair of tension members 4 in the cable thickness direction are adhered by the adhesive 11. Also, in the present embodiment, the tension member 4, the outer sheath 7, and the inner resin 6 are adhered by the adhesive 11 disposed on the entire circumference of the tension member 4, and the protective member 5, the outer sheath 7, and the inner resin 6 are adhered by the adhesive 11 disposed on both surfaces of the protective member 5.

[0019] Here, as described above, while the adhesive 11 is formed over the entire length of the optical cable 1 in the longitudinal direction of the cable, an example of a method for melting and curing the adhesive 11 will be described. The protective member 5 and the tension member 4 provided with the adhesive 11 on the surface are applied to the heater while being run past the heater, and the adhesive 11 is melted in order from one side in the running direction, and then the adhesive 11 is cured by cooling the protective member 5 and the tension member 4. Further, when the outer sheath 7 is formed by extrusion molding, the adhesive 11 may be melted by applying the heater to the protective member 5 and the tension member 4 during the process of feeding out the protective member 5 and the tension member 4 provided with the adhesive 11 at the time of extrusion molding of the outer sheath 7.

[0020] In the cable width direction, both end positions of each of the pair of protective members 5 are within the region R between the opposite ends of the pair of tension members 4. That is, the pair of protective members 5 do not protrude outside the pair of tension members 4 in the cable width direction. In the present embodiment, the position of the end of the protective member 5 in the cable width direction is located in the central region of the tension member 4 on the side closer to the end in the cable width direction. The central region of the tension member 4 in the cable width direction can be a region having a certain width, such as the central region when the tension member 4 is divided into three equal parts in the cable width direction.

[0021] Here, as shown in FIG. 2, the distance between the pair of protective members 5 facing each other in the cable thickness direction via the optical fiber core wire 2 and the internal resin 6 described later is L1, and the distance in the cable width direction between the pair of fixing portions 51, which are the portions fixed to the pair of tension members 4 in each protective member 5, is L2. At this time, the ratio of the distance L2 to the distance L1, that is, L2 / L1, is preferably 1.9 or more from the viewpoint of the bendability of the optical cable 1 in the cable thickness direction. Also, the ratio L2 / L1 preferably satisfies 4.2 or less from the viewpoint of preventing the protective member 5 from being bent when a mouse or the like bites the optical cable 1. For example, the distance L1 can be 1.12 mm or more and 1.72 mm or less, and the distance L2 can be 3.8 mm or more and 4.6 mm or less. The fixing portion 51 is a part of the protective member 5 and is the portion fixed to the tension member 4 via the adhesive 11. In the present embodiment, it is both ends of each protective member 5 in the cable width direction.

[0022] In the cross-section of the optical cable 1 orthogonal to the cable longitudinal direction, an enclosed region 12 closed by the pair of tension members 4, the pair of protective members 5, and the adhesive 11 is formed. In the present embodiment, the internal resin 6 is disposed in the enclosed region 12.

[0023] The inner resin 6 is more preferably made of a resin softer than the outer sheath 7. The inner resin 6 has a shore hardness at least lower than that of the outer sheath 7. For example, the inner resin 6 is made of low-density polyethylene, and the outer sheath 7 is made of linear low-density polyethylene resin. Note that the inner resin 6 may have a shore hardness equivalent to that of the outer sheath 7. Further, the inner resin 6 may be formed to be porous. A housing space 60 for housing the optical fiber core wire 2 and the two water-absorbing tapes 3 is formed over the entire length of the optical cable 1 at the central portion of the inner resin 6. Note that fibrous members such as PP yarn and aramid fiber may be filled around the optical fiber core wire 2 and the two water-absorbing tapes 3 in the housing space 60.

[0024] The outer sheath 7 covers a unit having the optical fiber core wire 2, the two water-absorbing tapes 3, the pair of tension members 4, the pair of protective members 5, the adhesive 11, and the inner resin 6 from the outer peripheral side. The outer sheath 7 can have a width (i.e., the dimension in the cable width direction) of 5.5 mm or more and 7.0 mm or less, and a thickness (i.e., the dimension in the cable thickness direction) of 2.5 mm or more and 3.5 mm or less. The outer sheath 7 includes an outer-sheath central portion 71 formed such that its outer surface is along the cable width direction, and outer-sheath end portions 72 formed on both sides of the outer-sheath central portion 71 in the cable width direction and having a curved outer surface. In a cross section of the optical cable 1 orthogonal to the cable longitudinal direction, the surface of the outer-sheath end portion 72 is formed in a substantially arc shape bulging outward in the cable width direction.

[0025] Here, the optical cable 1 is disassembled at its terminal portion or the like to take out the optical fiber core wire 2, and the taken-out optical fiber core wire 2 is connected to a counterpart device or the like. Therefore, in order to easily break the outer sheath 7 and the inner resin 6 when taking out the optical fiber core wire 2 from the optical cable 1, a first notch 73 is formed in the outer peripheral portion of the outer sheath 7, and a second notch 61 is formed in the outer peripheral portion of the inner resin 6. The first notch 73 and the second notch 61 are recesses formed in a V shape at the outer peripheral portions of the outer sheath 7 and the inner resin 6, respectively, and are formed to be long in the cable longitudinal direction.

[0026] The first notches 73 are formed one by one at both ends in the cable thickness direction in the outer sheath central portion 71. Each first notch 73 is formed at the central position of each outer sheath central portion 71 in the cable width direction. On the extension line obtained by extending the tip (the tip of the V shape) of each first notch 73 in the cable thickness direction, the central portion in the width direction of each protective member 5 and the optical fiber core wire 2 are arranged.

[0027] The second notches 61 are formed one by one at both ends in the cable thickness direction in the inner resin 6. Further, the two second notches 61 are formed at positions on the opposite sides in the cable width direction with the optical fiber core wire 2 interposed therebetween. The two second notches 61 are respectively formed at positions between each of the pair of tension members 4 in the cable width direction and the optical fiber core wire 2. The shortest distance between the tip of the second notch 61 and the accommodation space 60 is smaller than the shortest distance between the tip of the second notch 61 and the tension member 4 arranged on the side opposite to the optical fiber core wire 2 with respect to the second notch 61.

[0028] Next, an example of the state of disassembling the terminal of the optical cable 1 and taking out the optical fiber core wire 2 from the optical cable 1 will be described with reference to FIG. 3. FIG. 3 is a perspective view for explaining the state of taking out the optical fiber core wire 2 from the terminal of the optical cable 1 in the present embodiment.

[0029] First, although not shown, a tool such as nippers is inserted into the outer sheath 7 from the first notch 73, and the outer sheath 7 is peeled from the protective member 5. Next, by pulling both end portions of the outer sheath 7 to both sides in the cable width direction, a tensile force is applied to the inner resin 6 via the tension member 4 and the adhesive 11 disposed around the tension member 4. As a result, the inner resin 6 is divided starting from the second notch 61, and the optical fiber core wire 2 is taken out from the optical cable 1. Note that the method of taking out the optical fiber core wire 2 from the optical cable 1 described in the present embodiment is merely an example, and other taking out methods may be employed.

[0030] (Operations and Effects of the First Embodiment) In this embodiment, each protective member 5 is fixed to each of the pair of tension members 4. Therefore, even when a mouse bites the optical cable 1 or a cicada pierces the ovipositor into the optical cable 1, it is possible to suppress the teeth of the mouse, the ovipositor of the cicada, etc. from entering the surrounding area 12 surrounded by the pair of protective members 5 and the pair of tension members 4. Therefore, the optical cable 1 of this embodiment can easily and surely protect the optical fiber core wire 2. Different from this embodiment, when each protective member 5 and each of the pair of tension members 4 are not fixed, there is a possibility that the teeth of the mouse, the ovipositor of the cicada, etc. may reach the optical fiber core wire 2 through the space between the tension member 4 and the protective member 5.

[0031] In addition, since each protective member 5 is fixed to each of the pair of tension members 4 via the adhesive 11, it is possible to suppress the protective member 5 from peeling off from the tension member 4 and a gap being formed between the protective member 5 and the tension member 4 in the vicinity of the portion where the optical cable 1 is bitten. Therefore, it is easy to maintain the function of suppressing the teeth of the mouse, the ovipositor of the cicada, etc. from entering the surrounding area 12 surrounded by the pair of protective members 5 and the pair of tension members 4.

[0032] In addition, the ratio L2 / L1 of the interval L2 in the cable width direction between the pair of fixing portions 51 fixed to the pair of tension members 4 in the protective member 5 to the interval L1 between the pair of protective members 5 facing each other in the cable thickness direction via the optical fiber core wire 2 is 1.9 or more. If the ratio L2 / L1 is made excessively small, it becomes difficult for the optical cable 1 to bend in the cable thickness direction. By setting the ratio L2 / L1 to 1.9 or more, it is possible to prevent the optical cable 1 from being excessively difficult to bend in the cable thickness direction.

[0033] Also, the ratio L2 / L1 is 4.2 or less. The larger the ratio L2 / L1, the more likely the amount of deflection of the protection member 5 when a mouse or the like bites the optical cable 1 will be large, and the more likely the impact when a mouse or the like bites the optical cable 1 will be applied to the optical fiber core wire 2. By setting the ratio L2 / L1 to 4.2 or less, it is possible to prevent the force when a mouse or the like bites the optical cable 1 from acting excessively on the optical fiber core wire 2.

[0034] Also, an enclosed region 12 surrounded by the pair of tension members 4 and the protection member 5 is provided with the internal resin 6. And the Shore hardness of the internal resin 6 is equal to or less than the Shore hardness of the outer sheath 7. Therefore, when a mouse or the like bites the optical cable 1, it is possible to suppress the teeth of the mouse or the like from entering the outer sheath 7 due to the relatively hard outer sheath 7, and it is possible to absorb the impact when a mouse or the like bites the optical cable 1 by the relatively soft internal resin 6.

[0035] Also, a first notch 73 is formed in the outer peripheral portion of the outer sheath 7, and a second notch 61 is formed in the outer peripheral portion of the internal resin 6 at a position between each of the pair of tension members 4 and the optical fiber core wire 2 in the cable width direction. Therefore, even in a configuration where the optical fiber core wire 2 is surrounded by the internal resin 6 and the internal resin 6 is surrounded by the outer sheath 7, the optical fiber core wire 2 can be easily taken out from the optical cable 1 as described above.

[0036] Further, the protective members 5 are arranged in a pair on both sides in the cable thickness direction of the optical fiber core wire 2 and the pair of tension members 4, and each of the pair of protective members 5 is fixed to each of the pair of tension members 4. And in the cable width direction, both end positions of each of the pair of protective members 5 are within the region R between the opposite ends of the pair of tension members 4. Here, different from this embodiment, when the protective member 5 protrudes to both outer sides in the cable width direction of the pair of tension members 4, the end portion of the protective member 5 in the cable width direction bites deeply into the outer sheath 7, and there is a risk that cracks or the like are likely to occur in the outer sheath 7. Therefore, according to this embodiment, it is possible to prevent the end portion of the protective member 5 in the cable width direction from biting deeply into the outer sheath 7, and it is possible to suppress the occurrence of cracks in the outer sheath 7.

[0037] As described above, according to this embodiment, it is possible to provide an optical cable capable of protecting the optical fiber core wire from organisms such as cicadas and mice.

[0038] [Second Embodiment] The optical cable 1 according to the second embodiment will be described with reference to FIGS. 4 and 5. FIG. 4 is a cross-sectional view of the optical cable 1 in this embodiment. FIG. 5 is a perspective view for explaining a state of taking out the optical fiber core wire 2 from the terminal of the optical cable 1 in this embodiment.

[0039] This embodiment is a form in which the position of the first notch 73 is changed with respect to the first embodiment. In this embodiment, two first notches 73 are formed at both ends in the cable thickness direction of the outer sheath central portion 71 of the outer sheath 7.

[0040] Each first notch 73 is formed at a position overlapping in the cable thickness direction with a fixing portion 51 which is a portion fixed to the tension member 4 in the protection member 5. In the present embodiment, the four first notches 73 are formed at positions overlapping in the cable thickness direction with respect to the fixing portion 51 arranged at the position closest to each of them. Here, the fact that the first notch 73 is formed at a position overlapping with the fixing portion 51 in the cable thickness direction means that at least a part of the whole of the first notch 73 (the whole of the V-shape in the present embodiment) may overlap with the fixing portion 51 in the cable thickness direction. For example, the tip of the first notch 73 may be formed at a position outside the fixing portion 51 in the cable width direction.

[0041] Next, an example of the state of disassembling the end of the optical cable 1 and taking out the optical fiber core wire 2 from the optical cable 1 will be described with reference to FIG. 5. First, although not shown in the drawing, a tool such as nippers is inserted into the outer sheath 7 from the first notch 73, and the fixing portion 51 between the tension member 4 and the protection member 5 at the tip of the first notch 73 is peeled off. In the present embodiment, since the first notch 73 is at a position overlapping with the fixing portion 51 in the cable width direction, it is easy to perform the operation of peeling off the fixing portion 51 between the tension member 4 and the protection member 5 using a tool such as nippers. Then, by pulling both ends of the outer sheath 7 in both width directions, a tensile force is applied to the internal resin 6 via the tension member 4 and the adhesive 11 arranged around the tension member 4. As a result, the internal resin 6 is divided starting from the second notch 61, and the optical fiber core wire 2 is taken out from the optical cable 1.

[0042] Other configurations of the present embodiment are the same as those of the first embodiment. Among the reference numerals used in the second embodiment and subsequent embodiments, those the same as the reference numerals used in the previous embodiments represent the same components and the like as those in the previous embodiments unless otherwise specified.

[0043] (Operation and Effect of the Second Embodiment) In this embodiment, the first notch 73 is formed at a position overlapping with the fixing portion 51 of the protection member 5 in the cable thickness direction. Therefore, as described above, the operation of peeling the fixing portion 51 of the protection member 5 and the tension member 4 can be facilitated. In addition, this embodiment also has the same operations and effects as those of the first embodiment.

[0044] [Third Embodiment] The optical cable 1 according to the third embodiment will be described with reference to FIG. 6. FIG. 6 is a cross-sectional view of the optical cable 1 in this embodiment.

[0045] This embodiment is a form in which the number of optical fiber cores 2 included in the optical cable 1 is changed with respect to the second embodiment. In this embodiment, four optical fiber cores 2 are arranged in the accommodation space 60 of the internal resin 6. The four optical fiber cores 2 are arranged in two rows and two columns in the cable width direction and the cable thickness direction. And each water absorption tape 3 faces two optical fiber cores 2 in the nearer row among the four optical fiber cores 2 in the cable thickness direction. Other aspects are the same as those of the second embodiment.

[0046] (Actions and Effects of the Third Embodiment) In this embodiment, a plurality of optical fiber cores 2 are arranged in the surrounding region 12. Therefore, a plurality of optical fiber cores 2 can be protected. In addition, this embodiment also has the same operation and effect as those of the second embodiment.

[0047] [Fourth Embodiment] The optical cable 1 according to the fourth embodiment will be described with reference to FIGS. 7 to 9. FIG. 7 is a cross-sectional view of the optical cable 1 in this embodiment. FIG. 8 is a cross-sectional view taken along the line VIII-VIII in FIG. 7. FIG. 9 is a perspective view of the protection member 5 in this embodiment.

[0048] This form is a form in which the shape of the protection member 5 is changed with respect to the second embodiment. In this form, each of the pair of protection members 5 is formed in a wave shape that rises and falls on both sides in the cable thickness direction from one side to the other side in the cable longitudinal direction. The protection member 5 has a plurality of peak portions 52 protruding toward the side away from the tension member 4 and a plurality of valley portions 53 protruding toward the side approaching the tension member 4. And the protection member 5 is adhered to the tension member 4 via the adhesive 11 at each valley portion 53. Other aspects are the same as those of the second embodiment.

[0049] (Operation and Effect of the Fourth Embodiment) In this form, the protection member 5 is formed in a wave shape that rises and falls on both sides in the cable thickness direction from one side to the other side in the cable longitudinal direction. Therefore, it is possible to improve the ease of bending in the cable thickness direction in the optical cable 1. Also, even when a mouse or the like bites the optical cable 1, the protection member 5 becomes difficult to bend, and it becomes easier to protect the optical fiber core wire 2. In addition, in this form as well, it has the same operation and effect as those of the second embodiment.

[0050] [Fifth Embodiment] The optical cable 1 according to the fifth embodiment will be described with reference to FIG. 10. FIG. 10 is a cross-sectional view of the optical cable 1 in this form.

[0051] This form is a form in which a light guide 13 is added in the surrounding region 12 while having the same basic structure as the first embodiment. The light guides 13 are arranged one on each side in the cable width direction of the optical fiber core wire 2. The light guide 13 is a bundle light guide in which a plurality of optical fiber strands 21a (optical fiber core wires) for optical power feeding to a wireless device such as 5G (28 GHz band) are bundled. The optical fiber core wire 2 arranged in the accommodation space 60 of the internal resin 6 is an optical fiber core wire for communication.

[0052] The two light guides 13 are arranged within the internal resin 6. The second notch 61 of the internal resin 6 is arranged between the light guide 13 and the optical fiber core wire 2 in the cable width direction. The shortest distance between the tip of the second notch 61 and the accommodation space 60 is smaller than the shortest distance between the tip of the second notch 61 and the light guide 13 arranged on the side opposite to the optical fiber core wire 2 with respect to the second notch 61. Other aspects are the same as those of the first embodiment.

[0053] (Operations and Effects of the Fifth Embodiment) In this embodiment, a plurality of light guides 13 are arranged within the surrounding region 12 in addition to the optical fiber core wire 2. Therefore, in addition to the optical fiber core wire 2, a plurality of light guides 13 can be protected. In addition, in this embodiment as well, it has the same operations and effects as those of the first embodiment.

[0054] [Sixth Embodiment] The optical cable 1 according to the sixth embodiment will be described with reference to FIG. 11. FIG. 11 is a cross-sectional view of the optical cable 1 in this embodiment.

[0055] This embodiment is a form in which the configuration within the surrounding region 12 is changed with respect to the first embodiment. In this embodiment, four optical fiber core wires 2 are arranged in the surrounding region 12. When looking at a cross-section orthogonal to the cable longitudinal direction, the four optical fiber core wires 2 are arranged in two rows and two columns. Also, within the surrounding region 12, a plurality of fibrous members 14 are arranged so as to fill the periphery of the four optical fiber core wires 2 within the surrounding region 12. The fibrous member 14 is made of fibrous plastic such as PP yarn, and a large number of them are arranged within the surrounding region 12.

[0056] In addition, in the present embodiment, the first notch 73 is formed at a position between the optical fiber cores 2 adjacent in the cable width direction and at a position overlapping in the cable thickness direction. Here, the fact that the first notch 73 is formed at a position between the optical fiber cores 2 adjacent in the cable width direction and at a position overlapping in the cable thickness direction means that at least a part of the entire first notch 73 (the entire V-shaped part in the present embodiment) overlaps with the position between the adjacent optical fiber cores 2 in the cable width direction and the cable thickness direction. Also, in the present embodiment, the interval L1 can be set to be 1.64 mm or more and 2.44 mm or less, and the interval L2 can be set to be 5.8 mm or more and 6.6 mm or less. Other aspects are the same as those of the first embodiment.

[0057] (Actions and effects of the sixth embodiment) In the present embodiment, the surrounding region 12 is filled with a plurality of fibrous members 14. Therefore, when a mouse or the like bites the optical cable 1, the plurality of fibrous members 14 can absorb the impact, and the optical fiber core 2 can be further protected.

[0058] Also, in the present embodiment, the first notch 73 is formed at a position between the optical fiber cores 2 adjacent in the cable width direction and at a position overlapping in the cable thickness direction. Here, when a mouse or the like bites the optical cable 1, the teeth of the mouse or the like are likely to be guided to the first notch 73. Therefore, according to the present embodiment, even when the optical cable 1 is bitten by a mouse or the like from the first notch 73, it is possible to suppress the force of the optical cable 1 being bitten by the mouse or the like from reaching between the optical fiber cores 2 adjacent in the cable width direction and applying an impact to the optical fiber core 2. In addition, in the present embodiment as well, it has the same actions and effects as those of the first embodiment.

[0059] [Seventh embodiment] The optoelectronic composite cable 10 according to the seventh embodiment will be described with reference to FIG. 12. FIG. 12 is a cross-sectional view of the optoelectronic composite cable 10 in the present embodiment.

[0060] This embodiment relates to an optical and electrical composite cable 10 including the optical cable 1 of the sixth embodiment. The optical and electrical composite cable 10 of this embodiment includes an optical cable 1, a plurality of power lines (two first power lines 17 and a second power line 18), a pair of strip members 15 that cover the optical cable 1 and the plurality of power lines from both sides in the cable thickness direction, and a jacket 16 that covers these from the outer peripheral side. The plurality of power lines include three power lines, namely, two first power lines 17 having the same diameter as each other and a second power line 18 having a diameter smaller than that of the first power line 17. The optical cable 1, the two first power lines 17, and the one second power line 18 are formed side by side in the cable width direction, and the two first power lines 17 are located at both ends thereof.

[0061] The pair of strip members 15 can be formed of a laminated tape made of stainless steel, iron, or the like, similar to the protective member 5 of the optical cable 1. The strip member 15 is wide in the cable width direction and is vertically attached to the optical cable 1, the first power line 17, and the second power line 18. Both ends of the strip member 15 in the cable width direction are arranged at positions of one end of the two first power lines 17 in the cable thickness direction. Note that, similar to the protective member 5, an adhesive may be provided on the surface of the strip member 15, and the strip member 15 may be adhered to the jacket 16 and the two first power lines 17.

[0062] The jacket 16 is formed so as to collectively cover the optical cable 1, the first power line 17, the second power line 18, and the pair of strip members 15. The jacket 16 is made of a resin such as a polyethylene resin. Other aspects are the same as those of the sixth embodiment.

[0063] (Operations and Effects of the Seventh Embodiment) In this embodiment, since the optical cable 1 is covered by a pair of strip members 15, the impact acting on the optical fiber core wire 2 can be reduced by both the strip member 15 of the optical and electrical composite cable 10 and the protective member 5 of the optical cable 1. Further, for example, for the portion where the optical cable 1 is exposed at the terminal of the optical and electrical composite cable 10, the optical fiber core wire 2 can be protected from organisms such as rats and cicadas, similar to the first embodiment. In addition, in this embodiment as well, it has the same operational effects as the sixth embodiment.

[0064] (Summary of Embodiments) Next, the technical idea grasped from the above-described embodiments will be described by referring to the reference numerals and the like in the embodiments. However, each reference numeral and the like in the following description are not limited to the members and the like that specifically show the components in the claims in the embodiments.

[0065] [1] An optical cable (1) comprising an optical fiber core wire (2), a pair of tension members (4) arranged on both lateral sides of the optical fiber core wire (2), protective members (5) arranged on both sides in a direction orthogonal to both the arrangement direction of the pair of tension members (4) and the cable longitudinal direction in the optical fiber core wire (2) and the pair of tension members (4), and an outer sheath (7) covering the optical fiber core wire (2), the pair of tension members (4), and the protective members (5), wherein the protective members (5) are fixed to the respective ones of the pair of tension members (4).

[0066] [2] For the optical cable (1) according to [1], the ratio L2 / L1 of the interval L2 in the arrangement direction between a pair of fixing portions (51), which are the portions of the protective members (5) fixed to the pair of tension members (4), to the interval L1 between the protective members (5) facing each other in the orthogonal direction via the optical fiber core wire (2) is 1.9 or more.

[0067] [3] For the optical cable (1) according to [2], the ratio L2 / L1 is 4.2 or less.

[0068] [4] An internal resin (6) is disposed in an enclosed region (12) surrounded by the pair of tension members (4) and the protection member (5), and the Shore hardness of the internal resin (6) is equal to or less than the Shore hardness of the outer sheath (7). The optical cable (1) according to any one of [1] to [3].

[0069] [5] A first notch is formed in the outer peripheral portion of the outer sheath (7), and a second notch is formed in the outer peripheral portion of the internal resin (6) at a position between at least one of the optical fiber core wires (2) and the pair of tension members (4) in the arrangement direction. The optical cable (1) according to [4].

[0070] [6] The enclosed region (12) surrounded by the pair of tension members (4) and the protection member (5) is filled with a plurality of fibrous members (14). The optical cable (1) according to any one of [1] to [4].

[0071] [7] The pair of protection members (5) are arranged in a pair on both sides of the optical fiber core wire (2) and the pair of tension members (4) in the orthogonal direction, and each of the pair of protection members (5) is fixed to each of the pair of tension members (4). In the arrangement direction, both end positions of each of the pair of protection members (5) are within a region (R) between opposite ends of the pair of tension members (4). The optical cable (1) according to any one of [1] to [6].

[0072] [8] A first notch is formed in the outer peripheral portion of the outer sheath (7), and the first notch is formed at a position overlapping the fixing portion (51), which is a portion fixed to the tension member (4) in the protection member (5), in the orthogonal direction. The optical cable (1) according to [7].

[0073] [9] The optical fiber core wire (2) is a tape core wire formed by collectively coating a plurality of parallel optical fiber element wires with a tape coating, and a plurality of them are arranged. On the outer peripheral portion of the outer sheath (7), a first notch is formed, and the first notch is formed at a position between two adjacent optical fiber core wires (2) in the arrangement direction and at a position overlapping in the orthogonal direction. The optical cable (1) according to any one of [1] to [8].

[0074]

[10] The protective member (5) is formed in a wavy shape that goes up and down on both sides in the orthogonal direction as it goes from one side to the other side in the cable longitudinal direction. The optical cable (1) according to any one of [1] to [9].

[0075] (Supplementary Note) As described above, the embodiments of the present invention have been described. However, the above-described embodiments do not limit the invention according to the claims. Also, it should be noted that not all combinations of the features described in the embodiments are essential means for solving the problems of the invention. Further, the present invention can be appropriately modified and implemented without departing from its gist.

[0076] For example, as in each of the above embodiments, when there are a pair of protective members, at least one protective member may be fixed to each of the pair of tension members. Even in this case, compared with the case where each of the plurality of protective members is not fixed to each of the pair of tension members, an effect of protecting the optical fiber core wire from organisms such as cicadas and mice can be obtained.

[0077] Also, a pair of tension members may exist on both sides sandwiching the optical fiber core wire, and three or more other tension members may exist.

[0078] Also, in each of the above embodiments, an example where the optical fiber core wire is a tape core wire in which a plurality of element wires are covered with a tape coating is shown, but it is not limited to this, and the tape coating may not exist. That is, the optical fiber core wire may be composed of optical fiber element wires.

[0079] In addition, in each of the above embodiments, an example in which an adhesive is provided on each surface of the protective member and the tension member has been shown. However, it is sufficient that the adhesive is present at least between the protective member and each tension member.

[0080] Also, the fixation of the tension member and the protective member is not limited to using an adhesive, and for example, a fixing method other than adhesion such as welding can be adopted.

[0081] In addition, in each of the above embodiments, an example in which the optical cable has a pair of protective members has been shown, but it is not limited thereto. For example, one long protective member may be wound around a pair of tension members and fixed to the pair of tension members by adhesion or the like.

[0082] In addition, in each of the above embodiments, an example in which there are a pair of protective members has been shown, but there may be another protective member separately.

[0083] In addition, in each of the above embodiments, the tension member has a circular cross-section, but it is not limited thereto. For example, it can also be a quadrilateral having sides along the cable width direction and the cable thickness direction. In this case, it is easy to fix both surfaces in the cable thickness direction and the protective member over a wide range.

Explanation of Reference Numerals

[0084] 1... optical cable 12... surrounding region 14... fibrous member 2... optical fiber core 3... water-absorbing tape 4... tension member 5... protective member 51... fixing portion 6... internal resin 61... second notch 7... outer sheath 72... first notch R... region

Claims

1. An optical fiber core wire, a pair of tension members arranged on both sides of the optical fiber core wire, protective members arranged on both sides in a direction orthogonal to both the arrangement direction of the pair of tension members and the cable longitudinal direction in the optical fiber core wire and the pair of tension members, a jacket covering the optical fiber core wire, the pair of tension members, and the protective members, an internal resin arranged in an enclosed region surrounded by the pair of tension members and the protective members, and comprising: the protective members are arranged in a pair on both sides in the orthogonal direction in the optical fiber core wire and the pair of tension members, each of the pair of protective members is adhered to each of the pair of tension members, each of the pair of tension members is adhered to the jacket and the internal resin by an adhesive provided on the entire circumferential surface of each of the pair of tension members, the protective members are adhered to the jacket and the internal resin by adhesives provided on both surfaces of the protective members, in the arrangement direction, both end positions of each of the pair of protective members are within a region between opposite ends of the pair of tension members, an optical cable.

2. The ratio L2 / L1 of the interval L2 in the arrangement direction between a pair of adhesive portions, which are portions of the protective members adhered to the pair of tension members, to the interval L1 between the protective members facing each other in the orthogonal direction via the optical fiber core wire is 1.9 or more. The optical cable according to Claim 1.

3. The ratio L2 / L1 is 4.2 or less. The optical cable according to Claim 2.

4. The Shore hardness of the internal resin is equal to or less than the Shore hardness of the jacket. The optical cable according to any one of Claims 1 to 3.

5. A first notch is formed in the outer peripheral portion of the jacket. A second notch is formed in the outer peripheral portion of the internal resin at a position between at least one of the optical fiber core wire and the pair of tension members in the arrangement direction. The optical cable according to Claim 4.

6. The enclosed region surrounded by the pair of tension members and the protective members is filled with a plurality of fibrous members. The optical cable according to any one of Claims 1 to 4.

7. A first notch is formed in the outer peripheral portion of the jacket. The first notch is formed at a position overlapping in the orthogonal direction with respect to an adhesion portion which is a portion of the protection member adhered to the tension member. The optical cable according to any one of claims 1 to 6. **Claim 8** The optical fiber core wire is a tape core wire formed by collectively covering a plurality of parallel optical fiber strands with a tape coating, and a plurality of the tape core wires are arranged. A first notch is formed on an outer peripheral portion of the outer sheath. The first notch is formed at a position between two adjacent optical fiber core wires in the arrangement direction and at a position overlapping in the orthogonal direction. The optical cable according to any one of claims 1 to 7. **Claim 9** The protection member is formed in a wave shape that rises and falls on both sides in the orthogonal direction as it goes from one side to the other side in the longitudinal direction of the cable. The optical cable according to any one of claims 1 to 8.

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