JP5087492B2 - Fiber optic cable - Google Patents

Description

  The present invention relates to an optical fiber cable, and more particularly, a small-core aerial optical fiber cable or a small-scale building in which one or more optical fibers made of, for example, an optical fiber core wire are installed between utility poles when being drawn into a small-scale building or general home. Alternatively, the present invention relates to an optical fiber cable for drawing into a general household.

  Conventionally, FTTH (Fiber to the Home), that is, from an optical fiber cable of an access system extended from a telephone office to a building or general in order to be able to transmit and receive high-speed broadband information such as ultra-high-speed data at home or office For example, an optical fiber made of an optical fiber core or the like is pulled down to a subscriber's house such as a house, and an optical fiber drop cable is used for wiring the optical fiber. In other words, the optical fiber drop cable is used when drawing the optical fiber from the branch closure of the trunk cable on the utility pole into the home, and is mainly applied to the optical fiber drop cable (outdoor line) and a longer installation span. For this purpose, a small-core optical aerial cable with an increased support line size is used.

  As known in Patent Document 1 and Non-Patent Document 1, for example, referring to FIG. 7, as a conventional optical fiber drop cable 101, for example, an optical fiber 103 made of an optical fiber core and the like, Parallel to one of the two directions orthogonal to the longitudinal direction of the fiber 103 (the direction orthogonal to the paper surface in FIG. 7) and on both sides of the optical fiber 103 on a straight line passing through the center of the optical fiber 103 For example, a cross-sectional shape in which a pair of strength members 105 made of, for example, an aramid fiber FRP and the like are disposed extending in the same direction as the longitudinal direction of the optical fiber 103 and the outer periphery of the optical fiber 103 and the pair of strength members 105 are covered. Constitutes a long optical element portion 109 comprising a casing 107 made of a resin such as a non-halogen flame retardant sheath.

  In this optical element portion 109, a flat inclusion 111 is provided at a certain distance of the optical fiber 103 in the outer jacket 107 above and below the optical fiber 103.

  The long optical element 109 and the outer cover 117 made of resin in which a support wire 115 made of, for example, steel wire is coated on the left side of the outer cover 107 in FIG. A long optical fiber drop cable 101 is constituted by the integrated support line portion 119.

  The inclusion 111 is provided in the outer sheath 107 above and below the optical fiber 103 at a certain distance from the optical fiber 103, so that the bearfish stabs the egg-laying tube into the outer sheath 107, and light The occurrence of a failure that breaks the fiber 103 is prevented.

  In addition, as the optical fiber drop cable 121 that takes measures against damage of the oviposition of bearfish, the one shown in FIG. 8 is used. In FIG. 8, as the optical fiber drop cable 121, for example, an optical fiber 103 made of an optical fiber core or the like, and two directions orthogonal to the longitudinal direction of the optical fiber 103 (the direction orthogonal to the paper surface in FIG. 8). A pair of tensile strength composed of, for example, an aramid fiber FRP, which is arranged in parallel with one of the optical fibers 103 and extending in the longitudinal direction of the optical fiber 103 on both sides of the optical fiber 103 on a straight line passing through the center of the optical fiber 103. And an outer jacket 107 made of a high-strength resin having, for example, a rectangular cross-sectional shape and low friction and wear resistance, covering the outer periphery of the optical fiber 103 and the pair of tensile strength members 105. The long optical element unit 109 is configured.

  In the optical element portion 109, a notch portion 123 is formed on the surface of the jacket 107 above and below the optical fiber 103.

  The long optical element 109 and the outer cover 117 made of resin in which a support wire 115 made of, for example, steel wire is coated on the left side of the outer cover 107 in FIG. A long optical fiber drop cable 121 is constituted by the integrated support line portion 119.

  The outer cover 107 is made of a high-strength resin having low friction and wear resistance, so that measures are taken so that the laying tube does not pierce the outer cover 107.

Further, as known from Patent Document 2, a structure in which the outer cover has a two-layer structure, the hardness shore D of the inner cover is 65 or more, and the thickness is 0.15 mm or more is already known.
JP 2002-90591 A JP 2007-127848 A Proceedings of IEICE Proceedings 2007 Society Conference B-10-7

  By the way, in the optical fiber cable 101 shown in FIG. 7 as in the above-mentioned Patent Document 1 and Non-Patent Document 1, the inclusion 111 becomes an obstacle when the optical fiber 103 is taken out. In addition, there is a problem that it takes time and effort to cut out and remove the inclusion 111 that has come out of the outer jacket 107 to take out the optical fiber 103.

  Further, in the optical fiber cable 121 shown in FIG. 8 described above, since the high-strength outer jacket 107 is used, the ones and wedges of the resin outer casing gripping member are sufficiently attached to the high-strength outer jacket 107. There is a problem that it cannot be bitten and the grip strength of the outer jacket 107 is lowered. In addition, since the outer jacket 107 is hard, the tearing force required for tearing the outer jacket 107 is increased, and workability such as the lead-out property of the optical fiber 103 and the separation between the support wire portion 119 and the optical element portion 109 is reduced. . If the strength of the outer cover material is selected in consideration of the attachment property of the outer cover gripping member and the lead workability, the anti-kumazemi effect is reduced.

  Furthermore, in Patent Document 2, as a protective material, in addition to polyamide thermoplastic resin, ABS resin, ACS resin, AES resin, ABS / PVC alloy, ASA resin, ethylene-vinyl chloride copolymer, fluorine resin, polyamide Examples include imide, polyarylate, olefin vinyl alcohol copolymer, phenol resin, polybutylene terephthalate, polycarbonate, polyether sulfone, polythioether sulfone, polyethylene terephthalate, polyimide, norbornene resin, polyphenylene ether, polyphenylene sulfide, and polyvinyl chloride. ing. On the other hand, the jacket material of the optical fiber drop cable is made of olefin-based thermoplastic resin (polyethylene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate) due to the requirement of weather resistance against ultraviolet rays, combustion resistance, non-halogenation, etc. Copolymers etc.) as a main component, carbon black, and magnesium hydroxide as a flame retardant are generally used. These protective materials including polyamide-based resin applied as a suitable example in Patent Document 2 are poorly compatible with the flame-retardant olefin-based resin used as a jacket material for optical fiber drop cables, and have different melting points. Therefore, it is difficult to heat-seal during extrusion. In addition, as in the case of Patent Document 2, the structure in which the notch is provided on the short-diameter surface of the protective material, the outer layer jacket material can be provided even if the notch is provided in the center in the long width direction of the jacket member of the cable body. It is impossible to take out the fiber core wire by tearing the notch part at the same time, and after tearing the outer sheath, it is necessary to tear the protective material further and take out the optical fiber core wire There is a problem that workability is worse than that of a conventional optical fiber drop cable.

  In order to solve the above-mentioned problems, an object of the present invention is to protect an optical fiber from a spawning tube of a pupa and prevent a reduction in connection work.

In order to achieve the problem to be solved by the above invention, an optical fiber cable of the present invention includes one or more optical fibers arranged in the center, and
Extending in the same direction as the longitudinal direction of the optical fiber on both sides of the optical fiber on a straight line parallel to one of the two directions orthogonal to the longitudinal direction of the optical fiber and passing through the center of the optical fiber. A pair of tensile bodies arranged;
An outer sheath formed of an olefin-based thermoplastic non-halogen flame retardant resin having a Shore D hardness of 45 to 53 integrally covering the outer periphery of the optical fiber and a pair of strength members;
A long light comprising an outer layer outer notch portion formed on the surface of the outer layer jacket below and on a straight line parallel to the other direction of the two directions and passing through the center of the optical fiber. An optical fiber cable constituting the element part,
In the outer envelope between the pair of strength members, around the optical fiber , high density polyethylene or olefin thermoplastic resin, high density polyethylene, high molecular weight polyethylene, cyclic polyolefin, polypropylene In addition to forming an inner layer outer shell having a Shore D hardness of 55 to 64 , the outer layer outer cover notch portion is formed on the lower surface of the inner layer outer shell. Corresponding to the inner layer outer notch is formed,
The outer layer covering material and the inner layer covering material are integrated by heat fusion, and the inner layer covering is torn together from the notch portion for the outer layer covering provided in the outer layer covering. It is.

  In the optical fiber cable according to the present invention, in the optical fiber cable, it is preferable that long support wire portions, which are covered with a cover wire, are integrated with the optical element portion in parallel with each other.

  In the optical fiber cable of the present invention, in the optical fiber cable, a distance from the surface of the optical fiber including the minimum thickness of the notch portion for the inner layer jacket material to the surface of the inner layer jacket is 0.25 mm or more, It is preferable that a notch tip of the outer layer outer notch portion is located inside a line connecting the opening ends of the inner layer outer notch portion.

The optical fiber cable of the present invention includes one or more optical fibers disposed in the center,
Extending in the same direction as the longitudinal direction of the optical fiber on both sides of the optical fiber on a straight line parallel to one of the two directions orthogonal to the longitudinal direction of the optical fiber and passing through the center of the optical fiber. A pair of tensile bodies arranged;
An outer sheath formed of an olefin-based thermoplastic non-halogen flame retardant resin having a Shore D hardness of 45 to 53 integrally covering the outer periphery of the optical fiber and a pair of strength members;
A long light comprising an outer layer outer notch portion formed on the surface of the outer layer jacket below and on a straight line parallel to the other direction of the two directions and passing through the center of the optical fiber. An optical fiber cable constituting the element part,
A high density polyethylene, a high molecular weight polyethylene, a cyclic polyolefin, and a polypropylene are blended in a high density polyethylene or an olefin-based thermoplastic resin around the optical fiber and a pair of strength members. In addition, an inner layer outer shell having a Shore D hardness of 55 to 64 is formed, and the upper and lower surfaces of the inner layer outer shell correspond to the outer layer outer notch portion. Inner layer outer notch is formed,
The outer layer jacket and the inner layer jacket are integrated by heat-sealing, and the inner layer jacket is torn together from an outer layer jacket notch provided in the outer layer jacket. .

  In the optical fiber cable according to the present invention, in the optical fiber cable, it is preferable that long support wire portions, in which the optical element portion is coated with a support wire, are integrated in parallel with each other.

  In the optical fiber cable according to the present invention, in the optical fiber cable, a distance from the surface of the optical fiber including the minimum thickness of the inner layer jacket notch portion to the surface of the inner layer jacket is 0.25 mm or more. It is preferable that a notch tip of the outer layer jacket notch portion is located inside a line connecting the opening ends of the jacket notch portion.

  As will be understood from the means for solving the above problems, according to the present invention, the outer periphery of the optical fiber is in the outer layer coating having a Shore D hardness of 45 to 53 between the pair of strength members. Alternatively, since the inner layer jacket having a Shore D hardness of 55 or more is coated around the optical fiber and the pair of strength members in the outer layer coating, The optical fiber can be protected from the laying tube. In addition, since the Shore D hardness of the outer layer jacket is 53 or less, when gripping the outer layer jacket with the closure or the connector, the ony and wedges can be easily stuck into the outer layer jacket to ensure a stable gripping force. I can do it.

  Since the conventional inclusion is not used, the workability is not deteriorated by the inclusion at the time of taking out the optical fiber. Further, the inner layer jacket and the outer layer jacket are bonded and integrated by heat fusion, and the inner layer jacket notch portion of the inner layer jacket and the outer layer jacket notch portion of the outer layer jacket are aligned to align the outer layer jacket. At the same time as tearing the notch for the outer jacket, the inner jacket notch for the inner jacket is torn to tear the inner jacket at once by tearing the outer notch for the outer jacket. Therefore, it is possible to take out the optical fiber core wire and provide an optical fiber drop cable excellent in terminal workability.

    Embodiments of the present invention will be described below with reference to the drawings.

  Referring to FIG. 1, an optical fiber drop cable 1 includes one or more optical fibers 3 including, for example, an optical fiber core disposed in the center, and a longitudinal direction of the optical fiber 3 (in FIG. The optical fibers 3 are arranged on both sides of a straight optical fiber 3 that is parallel to one of the two directions orthogonal to each other (the direction perpendicular to FIG. 1) and that passes through the center of the optical fiber 3. A pair of strength members 5 made of, for example, an aramid fiber FRP and the like, and a non-halogen flame retardant sheath integrally coated on the outer periphery of the optical fiber 3 and the pair of strength members 5. The outer layer 7 and the outer layer formed on the lower surface of the outer layer 7 above and below the other direction (vertical direction in FIG. 1) of the two directions of the optical fiber 3. And the notch portion 9, and a light element portion 11 of the elongated consisting.

  In the outer sheath 7 between the pair of strength members 5, an inner sheath 13 having a higher hardness than the outer sheath is formed around the optical fiber 3. 13 is formed with an inner layer outer notch portion 15 corresponding to the outer layer outer jacket notch portion 11, and the outer layer outer shell 7 and the inner layer outer shell 13 are adhered to each other by heat fusion. It is integrated. The outer sheath 7 is made of an olefin-based thermoplastic non-halogen flame retardant resin (polyethylene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate) due to the requirement of weather resistance and combustion resistance to ultraviolet rays, non-halogenation, etc. Copolymers etc.) as main components, carbon black as a measure against ultraviolet deterioration, and a non-halogen flame retardant such as magnesium hydroxide as a flame retardant are suitable. As a material having a hardness (Shore D) of 55 or more constituting the inner layer jacket 13, as a material to be fused with the material of the outer layer jacket 7 by heat at the time of extrusion, high density polyethylene or olefin-based thermoplastic resin is used. A material obtained by blending density polyethylene, high molecular weight polyethylene, cyclic polyolefin, polypropylene, and the like and increasing the hardness is suitable.

  A long support line portion 23 made of an outer sheath 21 covering a support wire 19 made of, for example, a steel wire is integrated with the optical element portion 11 in parallel with each other via a neck portion 17. In this embodiment, the outer cover 21 is made of the same material as the outer layer cover 7.

  According to the above configuration, even when the bearfish stabs the egg-laying tube into the outer envelope 7, the inner envelope 13 having a higher hardness than the outer envelope 7 is formed around the optical fiber 3. The optical fiber 3 can be protected from being disconnected from the laying tube. In addition, since a non-halogen flame retardant sheath is used as the outer layer jacket 7, when the outer layer jacket 7 is gripped by a closure or a connector, the seam, the wedge, etc. can be easily stuck in the outer layer jacket 7 and stably gripped. Power can be secured.

  In this embodiment, it is important that the inner-layer jacket 13 has sufficient hardness so that the oviposition tube of the bearfish does not reach the optical fiber 3. In addition, in order to facilitate the lead-out of the optical fiber 3, the outer layer jacket 7 and the inner layer jacket 13 are adhered to each other by heat fusion, and the outer layer jacket 7 from the outer layer jacket notch portion 9 of the outer layer jacket 7. It is important that the outer envelope 7 and the inner envelope 13 are easily torn together when tearing. Furthermore, the outer jacket material of the outer jacket 7 must be hard enough to allow the wedge of the conventional resin outer gripping member to be bitten.

  Therefore, the results of investigations on the hardness and thickness of the material of the inner-layer jacket 13 for protecting the optical fiber 3 from the laying tube of the bearfish will be described.

The optical fiber cable 1 was produced using the resins A, B, and C having different Shore D hardnesses, installed in the field where the bearfish appeared, and the damage situation of the bearfish due to the spawning tube was investigated. The survey is shown in Table 1.

  As can be seen from the results in Table 1, the hardness of the material of the inner layer jacket 13 is Shore D hardness 55 or more, and the thickness including the minimum thickness of the inner layer jacket notch 15 is 0.25 mm or more. It was confirmed that it was possible to significantly reduce the number of injuries caused by the oviduct and to protect the optical fiber 3. Furthermore, the higher the hardness, the higher the anti-kumazemi effect, and the inner layer jacket 13 having a Shore D hardness of 63 or more is more preferable. In addition, the Shore D hardness of the inner layer jacket 13 is 70 or less. If it exceeds 70, it is too hard and the tearing force required when tearing the inner layer jacket notch 15 becomes 15 N or more, and the workability when the optical fiber 103 is led out to the specified length for mounting the connector is deteriorated. It is.

  Next, the notch tearability (extruding property of the optical fiber 3) will be described. In order to enable the optical fiber 3 to be easily taken out, the outer layer jacket 7 and the inner layer jacket 13 are bonded together by heat fusion. Thus, when the outer layer jacket 7 is torn from the outer layer jacket notch portion 11 provided in the outer layer jacket 7, it is important that the inner layer jacket 13 is torn together and the optical fiber 3 can be taken out. A line connecting the outer layer outer notch portions 9 of the outer layer outer jacket 7 at a time is a line connecting the openings of the inner layer outer jacket notch portions 15 of the inner layer outer jacket 13 as shown in FIG. Need to come inside.

As shown in FIG. 3, the outer layer jacket 7 is torn using tools 25A and 25B. As described above, the material of the inner layer jacket 13 has a high tearing force because it is necessary to increase the hardness from the viewpoint of the resistance to the komazemi. Therefore, even if the line connecting the outer layer jacket notch portion 11 of the outer layer jacket 7 is inside the line connecting the opening portion of the inner layer jacket notch portion 15 of the inner layer jacket 13, the outer layer jacket If the material 7 is soft, only the outer-layer jacket 7 is broken (torn), and the inner-layer jacket 13 is not torn and the optical fiber 3 cannot be led out. Moreover, when the material of the outer layer outer cover 7 is too hard, the wedge of the outer cover holding member is not pierced. Actually, the optical fiber cable 1 shown in FIG. 1 was prototyped with the thickness of the resin D shown in Table 1 being 0.3 mm as the outer jacket material of the inner jacket 13, and the hardness of the outer jacket 7 was variously changed. Using the resin, the lead-out property of the optical fiber 3 and the attachment property of the outer cover gripping member of the connector were confirmed. The results are shown in Table 2.

  As can be seen from the results in Table 2, it was confirmed that the Shore D hardness of 45 to 53 was within an appropriate range. The thickness is preferably 0.1 mm or more and 0.35 mm or less. To make the dimension of the minor axis direction of the optical element portion 11 within the same tolerance of 1.8 to 2.2 mm as in the conventional optical fiber cable, and to attach the outer layer jacket 7 and the inner layer jacket 13 together and to tear them together The outer layer jacket 7 needs to have a thickness of 0.1 mm or more, and the thickness including the minimum thickness of the inner layer jacket notch portion 15 is 0.25 mm or more in order to obtain effective bear resistance. In order to achieve this, it is desirable to set the thickness of the outer envelope 7 to 0.35 mm or less.

  From the above, the hardness of the material of the inner layer jacket 13 is set to 55 or more Shore D hardness, 0.25 mm including the minimum thickness of the inner layer jacket notch portion 15, and the outer layer jacket 7 is made of a non-halogen flame retardant sheath. By doing so, the optical fiber 3 can be protected from the egg-laying tube of the koma-zemi by the high-strength inner layer jacket 13 around the optical fiber 3. Both the outer layer jacket 7 and the inner layer jacket 13 are provided with an outer layer jacket notch portion 9 and an inner layer jacket notch portion 15, and each outer layer jacket notch portion 9 and inner layer jacket notch portion 15. The tip of the outer layer jacket notch portion 9 is positioned inside the line connecting the opening ends of the inner layer jacket notch portion 15. Further, the outer layer jacket 7 and the inner layer jacket 13 are bonded and integrated, and the outer layer jacket 7 and the inner layer jacket 13 are formed by setting the Shore D hardness of the material of the outer layer jacket 7 in the range of 45 to 53. Can be torn together from the outer layer jacket notch portion 11 and the inner layer jacket notch portion 15 to realize an optical fiber drop cable 1 that can be attached to a jacket, a connector or other jacket gripping member. Can do.

    The operation of the optical fiber drop cable 1 will be described as follows.

  (1) Since the high-hardness inner layer jacket 13 is coated around the optical fiber 3, the high-hardness inner layer jacket 13 can protect the optical fiber 3 from the spawning tube of the Kumaemi.

  (2) Since no inclusion is used as in the conventional optical fiber drop cable 1, the takeout property of the optical fiber 3 is good.

  (3) Since the outer layer jacket 7 made of a non-halogen flame retardant sheath having a Shore D hardness of 45 to 53 is coated on the inner layer jacket 13 having a high hardness, the inner layer jacket 13 having a high strength is aged over time such as ultraviolet rays. Can be protected from. For this reason, it becomes possible to protect the optical fiber 3 for a long time from a bear seminar.

  (4) It is possible to apply the inner layer jacket 13 with high hardness by extrusion molding, and the degree of freedom in designing the covering shape is high.

  (5) The outer-layer jacket 7 and the inner-layer jacket 13 can be torn together from the outer-layer jacket notch portion 11, and the optical fiber 3 can be easily taken out.

  FIG. 4 shows a cross-sectional view of an optical fiber drop cable 27 according to another embodiment instead of FIG. In FIG. 4, the same members as those in FIG. 1 are denoted by the same reference numerals, and redundant description is omitted.

  In FIG. 4, instead of the inner layer jacket 13 in FIG. 1, an inner layer jacket 29 having a rectangular cross section is provided, and a large number of protrusions 31 are provided on the surface of the inner layer jacket 29. Since other than that is the same as FIG. 1, detailed description is abbreviate | omitted. Since the high-density polyethylene used for the material of the inner layer jacket 13 generally has a higher melting point than the olefin-based thermoplastic non-halogen flame retardant resin used for the material of the outer layer jacket 7, the resin of the outer layer jacket material at the time of extrusion If the temperature is not sufficiently high, it may be difficult to heat-seal both sufficiently. FIG. 4 shows a structure considering such a state.

  With the above configuration, by forming the inner layer jacket 29 having a large number of protrusions 31 on the surface, the contact area with the outer layer jacket 7 is increased, and the outer layer jacket 7 and the inner layer jacket 29 are in close contact with each other. It can be integrated with increased power. Further, since the projecting portion has a small cross-sectional area, it can be easily melted by touching the outer envelope 7 during extrusion and can be fused to the material of the outer envelope 7. Other operations and effects are the same as those described above.

  FIG. 5 shows a cross-sectional view of an optical fiber drop cable 33 of another embodiment instead of FIG. In FIG. 4, the same members as those in FIG. 1 are denoted by the same reference numerals, and redundant description is omitted.

  In FIG. 5, instead of the inner layer jacket 13 in FIG. 1, an inner layer jacket 35 whose cross-sectional shape is a rectangular shape with each side curved. Since other than that is the same as FIG. 1, detailed description is abbreviate | omitted.

  With the above configuration, by forming the inner layer jacket 35 whose cross-sectional shape is a rectangular shape in which each side is curved, the contact area with the outer layer jacket 7 is increased. The area to be protected from the oviposition tube of Kumazemi can be increased. Other operations and effects are the same as those described above.

  FIG. 6 shows a cross-sectional view of an optical fiber drop cable 37 of another embodiment instead of FIG. In FIG. 6, the same members as those in FIG.

  In FIG. 6, instead of the inner layer jacket 13 in FIG. 1, an inner layer jacket 39 is formed around the optical fiber 3 and a pair of strength members 5 in the outer layer jacket 7. . Since other than that is the same as FIG. 1, detailed description is abbreviate | omitted.

  With the above-described configuration, the high-strength inner-layer jacket 39 having a cross-sectional shape in the outer-layer jacket 7 and formed around the optical fiber 3 and the pair of strength members 5 has a high strength. The effect of increasing the area that can be protected from the oviposition tube of the oat in the inner layer jacket 39 and the arrangement of the tensile body 5 in the inner layer jacket 39 until the outer layer jacket 7 is coated after the inner layer jacket 39 is coated. In the meantime, there is an effect of preventing an increase in the loss of the optical fiber 3 due to shrinkage of the inner layer jacket 39 or the like. Other operations and effects are the same as those described above.

  1 to 6 described above is an example of an optical fiber drop cable, but it is also applicable to an indoor optical fiber cable.

It is sectional drawing which shows the optical fiber cable of this invention. It is explanatory drawing for demonstrating the tearing state of the optical fiber cable in FIG. In FIG. 2, it is explanatory drawing for demonstrating an example which tears an outer layer envelope with a tear tool. It is sectional drawing which shows the other optical fiber cable which replaces FIG. 1 of this invention. It is sectional drawing which shows the other optical fiber cable which replaces FIG. 1 of this invention. It is sectional drawing which shows the other optical fiber cable which replaces FIG. 1 of this invention. It is sectional drawing which shows the conventional optical fiber cable. It is sectional drawing which shows the other conventional optical fiber cable.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical fiber drop cable 3 Optical fiber 5 Strength body 7 Outer layer jacket 9 Outer layer jacket notch part 11 Optical element part 13 Inner layer jacket 15 Inner layer jacket notch part 17 Neck part 19 Support line 21 Outer cover 23 Support line part 25A 25B Tool 27 Optical fiber drop cable 29 Inner layer jacket 31 Protrusion 33 Optical fiber drop cable 35 Inner layer jacket 37 Optical fiber drop cable 39 Inner layer jacket

Claims (6)

One or more optical fibers placed in the center,
Extending in the same direction as the longitudinal direction of the optical fiber on both sides of the optical fiber on a straight line parallel to one of the two directions orthogonal to the longitudinal direction of the optical fiber and passing through the center of the optical fiber. A pair of tensile bodies arranged;
An outer sheath formed of an olefin-based thermoplastic non-halogen flame retardant resin having a Shore D hardness of 45 to 53 integrally covering the outer periphery of the optical fiber and a pair of strength members;
A long light comprising an outer layer outer notch portion formed on the surface of the outer layer jacket below and on a straight line parallel to the other direction of the two directions and passing through the center of the optical fiber. An optical fiber cable constituting the element part,
In the outer envelope between the pair of strength members, around the optical fiber , high density polyethylene or olefin thermoplastic resin, high density polyethylene, high molecular weight polyethylene, cyclic polyolefin, polypropylene In addition to forming an inner layer outer shell having a Shore D hardness of 55 to 64 , the outer layer outer cover notch portion is formed on the lower surface of the inner layer outer shell. Corresponding to the inner layer outer notch is formed,
The outer layer jacket material and the inner layer jacket material are integrated by heat fusion, and the inner layer jacket is torn together from the outer layer jacket notch provided in the outer layer jacket. Fiber cable.   2. The optical fiber cable according to claim 1, wherein a long support line portion in which a support line is covered with a jacket is integrated in parallel with the optical element portion.   The distance from the surface of the optical fiber including the minimum thickness of the inner layer jacket notch part to the surface of the inner layer jacket is 0.25 mm or more, and the line connecting the opening ends of the inner layer jacket notch part The optical fiber cable according to claim 1 or 2, wherein a notch tip of the outer layer jacket notch portion is located inside. One or more optical fibers placed in the center,
Extending in the same direction as the longitudinal direction of the optical fiber on both sides of the optical fiber on a straight line parallel to one of the two directions orthogonal to the longitudinal direction of the optical fiber and passing through the center of the optical fiber. A pair of tensile bodies arranged;
An outer sheath formed of an olefin-based thermoplastic non-halogen flame retardant resin having a Shore D hardness of 45 to 53 integrally covering the outer periphery of the optical fiber and a pair of strength members;
A long light comprising an outer layer outer notch portion formed on the surface of the outer layer jacket below and on a straight line parallel to the other direction of the two directions and passing through the center of the optical fiber. An optical fiber cable constituting the element part,
A high density polyethylene, a high molecular weight polyethylene, a cyclic polyolefin, and a polypropylene are blended in a high density polyethylene or an olefin-based thermoplastic resin around the optical fiber and a pair of strength members. In addition, an inner layer outer shell having a Shore D hardness of 55 to 64 is formed, and the upper and lower surfaces of the inner layer outer shell correspond to the outer layer outer notch portion. Inner layer outer notch is formed,
An optical fiber cable in which the outer layer jacket and the inner layer jacket are integrated by heat-sealing, and the inner layer jacket is torn together from a notch portion for the outer layer jacket provided in the outer layer jacket . 5. An optical fiber cable according to claim 4, wherein a long support line part in which a support line is covered with a jacket is integrated with the optical element part in parallel with each other. The distance from the surface of the optical fiber including the minimum thickness of the inner layer jacket notch part to the surface of the inner layer jacket is 0.25 mm or more, and the line connecting the opening ends of the inner layer jacket notch part inside, according to claim 4 or 5, wherein the optical fiber cable, characterized in that the notch tip of the outer sheath notch portion is positioned.

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