JP2010217316A - Cable traction terminal structure and optical cable - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simplify the constitution of a cable traction terminal structure 9 and also to lower the manufacturing cost of the cable traction terminal structure 9 by decreasing the number of components of the cable traction terminal structure 9. <P>SOLUTION: An optical fiber insertion hole 17 into which a lead-out portion of an optical fiber can be inserted is formed in a holder 13, and a tension member insertion hole 19 into which a lead-out portion of a tension member 5 is inserted is formed in the holder 13. A thin part 21 for caulking the lead-out portion of the tension member 5 is formed on an outer peripheral surface of the holder 13 outside the tension member insertion hole 19, A protection tube 25 is threadably engaged with a tip side of the holder 13, and a tool 33 to be towed is threadably engaged with a tip side of the protection tube 25. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a cable pulling terminal structure and the like used when pulling an optical cable formed by leading an optical fiber and a tension member from a terminal with a pulling member.

  In recent years, along with the development of optical communication technology using optical fibers, various developments have been made on the cable pulling terminal structure in an optical cable. The configuration of the cable pulling terminal structure according to the prior art will be briefly described as follows.

  That is, a holding tool (cylindrical member (11) in Patent Document 1) is provided on the terminal side of the optical cable so as to hold it. Further, a protective tube (flexible tube (16) in Patent Document 1) is provided on the distal end side of the holder, and this protective tube has flexibility, and leads out the optical fiber. The part and the lead-out part of the tension member are accommodated. A towed tool (end cap (12) in Patent Document 1) is provided on the distal end side of the protective tube, and a tension member lead-out portion is integrally fixed to the towed tool. And the connection part (eye nut (15) in patent document 1) which can be connected with the front-end | tip part of a pulling rope (an example of a pulling member) is provided in the front end side.

  Therefore, the tip of the tow rope is connected to the connecting portion of the towed tool, and the tow rope is wound by driving a winder such as a winch, so that the towing force of the tow rope is directly transmitted from the towed tool to the tension member. The optical cable is pulled in a predetermined pulling direction while causing the optical cable to move. Thereby, an optical cable can be pulled out from the cable drum arrange | positioned in the position spaced apart from the winder, and can be installed in a predetermined installation location.

  In addition, as prior art relevant to the present invention, there are those shown in Patent Literature 2 and Patent Literature 3 in addition to Patent Literature 1.

JP 2000-32473 A JP 2002-333561 A JP-A-9-197183

  In order to prevent damage to the lead-out portion of the optical fiber due to interference with the lead-out portion of the tension member during pulling of the optical cable, an optical fiber guide portion that guides the lead-out portion of the optical fiber (groove (80) in Patent Document 1) And an interference avoiding member (a cylindrical elastic member (8) in Patent Document 1) provided with a tension member guide portion (through hole (81) in Patent Document 1) for guiding the lead-out portion of the tension member inside the protective tube It is necessary to arrange. Therefore, there is a big problem that the number of parts of the cable pulling terminal structure is increased and the manufacturing cost of the cable pulling terminal structure is increased.

  Accordingly, an object of the present invention is to provide a cable pulling terminal structure having a novel configuration that can solve the above-described problems.

  The terminal-side feature of the present invention (characterized by the invention described in claim 1) is a cable pulling terminal structure used when pulling an optical cable formed by leading an optical fiber and a tension member from a terminal with a pulling member. The tension member is provided so as to be held on the end side of the optical cable, a screw portion (for example, a male screw portion for a holder) is formed on an outer peripheral surface, an optical fiber insertion hole through which the lead-out portion of the optical fiber can be inserted is formed, and the tension member A tension member insertion portion into which the lead-out portion of the tension member can be inserted, and a holder formed with a thin wall portion that crimps the lead-out portion of the tension member outside the tension member insertion portion on the outer peripheral surface; A threaded portion that can be screwed into a threaded portion (for example, a female threaded portion) of the holder is formed, and is screwed onto the distal end side of the retainer. A flexible protective tube that houses the lead-out portion of the protective tube, and a threaded portion (for example, a male threaded portion for a traction tool) that can be screwed onto the threaded portion of the protective tube on the outer peripheral surface. The gist is provided with a towed tool provided by screwing and having the pulling member on the tip side.

  According to the first feature, the traction member is connected to the connection portion of the towed device, and the traction member is wound by driving a winder, whereby the traction force of the traction member is removed from the protection tube. The optical cable is pulled in a predetermined pulling direction while being transmitted to the tension member directly to the connecting portion or from the protective tube via the thin portion of the holder. Thereby, the optical cable can be pulled out from the cable drum disposed at a position separated from the winder and laid at a predetermined laying position.

  Here, since the tension member lead-out portion is caulked by the thin-walled portion of the holder in a state where the tension member lead-out portion is inserted into the tension member insertion portion of the holder, the tension member insertion The corresponding portion of the portion is plastically deformed and crushed, and the middle portion of the lead-out portion of the tension member is sandwiched between the inner walls of the tension member insertion portion. In other words, the tension member is inserted into the tension member. It will be clamped mechanically firmly to the part. Thereby, even if a large traction force (for example, a traction force of several hundred kg or more) is applied, the holder does not come out of the optical cable.

  After the completion of the laying of the optical cable, the protective tube is removed from the terminal side of the optical cable, and the optical cable is optically connected to the optical cable on the other side.

  According to a second feature of the present invention (feature of the invention described in claim 2), in addition to the feature on the terminal side, the protective tube has a threaded portion formed on the inner peripheral surface and is made of a metal inner tube, and The gist is that a protective layer made of resin is provided on the outer peripheral surface of the inner tube.

  A third feature of the present invention (a feature of the invention described in claim 3) is that, in addition to the first feature or the second feature, two tension members on both sides of the optical fiber housing portion of the optical cable. The gist is that is arranged.

  According to a fourth feature of the present invention (a feature of the invention described in claim 4), the optical cable includes a cable pulling terminal structure including any one of the first to third features. The gist.

  According to the present invention, the number of parts of the cable pulling terminal structure can be reduced, and the manufacturing cost of the cable pulling terminal structure can be reduced.

It is a figure which shows the cable pulling terminal structure which concerns on embodiment of this invention. It is a periphery enlarged view of the holder in the cable pulling terminal structure concerning an embodiment of the present invention. It is sectional drawing along the III-III line in FIG. FIG. 4 is an enlarged view of an arrow portion IV in FIG. 3. FIG. 5 is a view taken along line V-V in FIG. 2, and an optical fiber and a tension member are omitted. It is sectional drawing along the VI-VI line in FIG. It is an enlarged view of the periphery of the towed tool in the cable pulling terminal structure according to the embodiment of the present invention. It is sectional drawing of the optical cable which concerns on embodiment of this invention. It is a periphery enlarged view of the holder of another aspect in the cable pulling terminal structure concerning the embodiment of the present invention. It is a periphery enlarged view of the holder of another aspect in the cable pulling terminal structure concerning the embodiment of the present invention.

  A general configuration of an optical cable according to an embodiment of the present invention and a configuration of a cable pulling terminal structure according to an embodiment of the present invention will be sequentially described with reference to FIGS.

  As shown in FIG. 8, the optical cable 1 according to the embodiment of the present invention has two tension members (steel wires or the like) 5 along both sides of an optical fiber housing portion 3 in which optical fibers (not shown) are arranged. In other words, tension members 5 are embedded on both sides of the outer peripheral surface of the sheath 7, in other words, a pair of tension members 5 are symmetrically disposed on both sides of the optical fiber storage portion 3. ing. Here, as shown in FIG. 3, in the optical cable 1, the optical fiber and the pair of tension members 5 are led out from the end of the optical cable 1.

  As shown in FIG. 1, a cable pulling terminal structure 9 according to an embodiment of the present invention is a structure used when pulling an optical cable 1 with a pulling rope 11 (an example of a pulling member). Is provided. And the concrete structure of the cable pulling terminal structure 9 is as follows.

  As shown in FIG. 1 to FIG. 3, a metal holder 13 made of stainless steel or the like is provided on the terminal side of the optical cable 1, and the outer peripheral surface of the holder 13 (the hollow of the holder 13 is provided). A screw portion (for example, a male screw portion for a holder) 15 is formed on the outer peripheral surface of the shaft portion 13a. In addition, a large-diameter optical fiber insertion hole 17 through which the optical fiber lead-out portion can be inserted is formed in the center of the end face of the holder 13 so as to penetrate along the cable axial direction D. A pair of tension member insertion holes (tension member insertion portions) 19 into which the tension member 5 can be inserted and whose diameter is smaller than that of the optical fiber insertion hole 17 are formed along the cable axis direction D on both sides of the optical fiber insertion hole 17 in FIG. (See FIG. 5). As shown in FIG. 4, thin portions 21 for caulking the lead-out portion of the tension member 5 by plastic deformation are formed in a concave shape on the outer peripheral surface of the holder 13 on the outer side of each tension member insertion hole 19. (Refer to FIG. 6) The formation location of each thin portion 21 is the hollow shaft portion 13 a of the holder 13, and is somewhat closer to the proximal end than the screw portion 15. Furthermore, an annular step portion 23 is formed at the boundary between the hollow shaft portion 13 a and the base portion 13 b of the holder 13.

  In addition, instead of making the formation part of each thin part 21 somewhat closer to the proximal end than the screw part 15 in the hollow shaft part 13a of the holder 13, as shown in FIG. 9, the hollow shaft part of the holder 13 It may be slightly closer to the tip than the screw portion 15 in 13a, or may be a base portion 13b of the holder 13 as shown in FIG.

  As shown in FIGS. 1 and 2, a flexible protective tube 25 is screwed onto the distal end side of the holder 13, and this protective tube 25 accommodates an optical fiber lead-out portion. To do. The protective tube 25 includes an inner tube 27 made of metal such as stainless steel. Inside the inner tube 27, a threaded portion (for example, a female threaded portion) 29 that can be screwed into the threaded portion 15 of the holder 13. Is formed. A protective layer 31 made of resin such as vinyl chloride is formed on the outer peripheral surface of the inner tube 27. The base end surface (on the optical cable 1 side) of the protective tube 25 is pressed against the stepped portion 23 of the holder 13 when the protective tube 25 and the holder 13 are connected to seal the inside of the protective tube 25 (waterproof). ).

  As shown in FIGS. 1 and 7, a to-be-towed tool 33 made of metal such as stainless steel is screwed onto the distal end side of the protective tube 25. Further, a threaded portion (for example, a male threaded portion for a towed tool) 35 that can be screwed onto the threaded portion 29 of the protective tube 25 is provided on the outer circumferential surface of the towed tool 33 (the outer circumferential surface of the hollow shaft portion 33a of the towed tool 33). A stepped portion 37 is formed at the boundary between the hollow shaft portion 33a and the base portion 33b of the towed tool 33 so that the distal end surface of the protective tube 25 can be pressed. An attachment screw 39 is integrally provided at the tip of the towed tool 33, and an eye nut (connection portion) 41 that can be connected to the towing rope 11 is screwed into the attachment screw 39. It has been. In other words, the towed tool 33 includes the eye nut 41 that can be connected to the tow rope 11 on the distal end side.

  The vicinity of the boundary between the outer peripheral surface of the holder 13 and the outer peripheral surface of the sheath, the vicinity of the boundary between the outer peripheral surface of the holder 13 and the outer peripheral surface of the protective tube 25, and the outer peripheral surface of the protective tube and the outer peripheral surface of the towed device 33 In the vicinity of the boundary, a waterproof tape (not shown) is wound to form a waterproof structure.

  Then, the effect | action and effect of embodiment of this invention are demonstrated.

  By connecting the tow rope 11 to the eye nut 41 of the towed tool 33 and winding the tow rope 11 by driving a winder such as a winch (not shown), the tow force of the tow rope 11 is protected from the towed tool 33. The optical cable 1 is pulled in a predetermined pulling direction while being transmitted to the tension member 5 via the tube 25 and the thin portion 21 of the holder 13. Thereby, the optical cable 1 can be pulled out from a cable drum (not shown) disposed at a position separated from the winder and laid at a predetermined laying position.

  The fixing structure of the tension member 5 will be described in detail.

  When the two thin portions 21 of the holding tool 13 are pressed in a state where the tension member insertion hole 19 of the holder 13 is housed in the tension member insertion hole 19, the tension member insertion hole 19 in that part is plastically deformed. By being crushed, a part of the tension member 5 passing through the inside of the thin wall portion 21 in the longitudinal direction is sandwiched between the inner walls of the tension member insertion hole 19. Will be pinched firmly. As a result, the holder 13 does not come out of the optical cable 1 even when a large traction force (for example, a traction force of several hundred kg or more) is applied.

  Further, since the tip end of the tension member 5 is cut so as not to protrude from the tip end of the holder 13, the tension member 5 protrudes inside the cable pulling terminal structure 9 and damages the lead-out portion of the optical fiber. There is no.

  After completing the laying of the optical cable 1, the protective tube 25 is removed from the terminal side of the optical cable 1, and the optical cable 1 is optically connected to the optical cable on the other side.

  Here, the protection tube 25 is screwed and provided on the distal end side of the holding tool 13, and the to-be-towed tool 33 is screwed and provided on the distal end side of the protection tube 25. Since the lead-out portion of the tension member 5 is caulked and fixed by the portion 21, the threaded portion 29 of the protective tube 25 and the threaded portion 35 of the to-be-towed tool 33 are screwed together, the threaded portion 29 of the protective tube 25 and the holding tool 13 The screwed state with the screw portion 15 is released. In other words, the cable pulling terminal structure 9 including the protective tube 25 can be detached from the optical cable 1 without cutting a part of the lead-out portion of the tension member 5.

  Therefore, according to the embodiment of the present invention, the number of parts of the cable traction terminal structure 9 can be reduced, and the configuration of the cable traction terminal structure 9 can be simplified and the manufacturing cost of the cable traction terminal structure 9 can be reduced. .

  Further, since the protective tube 25 can be removed from the end side of the optical cable 1 without cutting a part of the lead-out portion of the tension member 5, there is no need to perform a terminal processing operation such as opening the tension member again. Therefore, the efficiency of the optical connection work of the optical cable 1 can be sufficiently increased.

  In addition, this invention is not restricted to description of the above-mentioned embodiment, In addition, it can implement in a various aspect. Further, the scope of rights encompassed by the present invention is not limited to these embodiments.

DESCRIPTION OF SYMBOLS 1 Optical cable 3 Optical fiber storage part 5 Tension member 9 Cable pulling terminal structure 11 Pulling rope (traction member)
13 Holder 13a Hollow shaft portion 13b Base portion 15 Screw portion 17 Optical fiber insertion hole 19 Tension member insertion hole 21 Thin wall portion 25 Protective tube 27 Inner tube 29 Screw portion 31 Protective layer 33 Towed tool 33a Hollow shaft portion 33b Base portion 35 Screw portion 41 Eyenut (connection part)

Claims (4)

In the cable pulling terminal structure used when pulling the optical cable formed by extracting the optical fiber and the tension member from the terminal with the pulling member,
It is provided so as to be held on the terminal side of the optical cable, a thread portion is formed on the outer peripheral surface, an optical fiber insertion hole through which the optical fiber lead-out portion can be inserted is formed, and the lead-out portion of the tension member can be inserted A holder in which two tension member insertion portions are formed, and a thin portion for caulking the lead-out portion of the tension member is formed outside the tension member insertion portion on the outer peripheral surface;
A threaded portion that can be screwed to the threaded portion of the holder is formed on the inner peripheral surface, and is provided by being screwed to the distal end side of the holder, and is a flexible protection that houses the lead-out portion of the optical fiber Tubes,
A threaded portion that can be screwed to the threaded portion of the protective tube is formed on the outer peripheral surface, and is provided by being threadedly engaged with the distal end side of the protective tube, and provided with a connecting portion that can be coupled to the pulling member on the distal end side. A towing tool,
A cable towing terminal structure characterized by comprising:   2. The protective tube according to claim 1, further comprising: a metal inner tube having a threaded portion formed on an inner peripheral surface thereof; and a resin protective layer provided on the outer peripheral surface of the inner tube. Cable towing terminal structure.   The cable pulling terminal structure according to claim 1 or 2, wherein the two tension members are disposed on both sides of the optical fiber housing portion of the optical cable.   An optical cable comprising the cable pulling terminal structure according to any one of claims 1 to 3.

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