Optical connector fixing member

Abstract

To provide an optical connector fixing member capable of appropriately fixing an optical cable and having good workability.SOLUTION: An optical connector fixing member 11 includes a crimping sleeve 11A, an inner ring 11B, and an outer ring 11C. A proximal end insertion portion 11e of the crimping sleeve 11A is press-fitted inside from a distal end edge of a sheath 9. Tensile strength fiber 10 extended from the sheath 9 is held between an inner ring 11B and an extension portion 11g of the crimping sleeve 11A. The outer ring 11C holds the tensile strength fiber 10 extended from the sheath 9 by its tip portion and the inner ring 11B relative to the extension portion 11g of the crimping sleeve 11A, and holds the tensile strength fiber 10 in the sheath 9, the sheath 9, and the inner ring 11B are held relative to the proximal end insertion portion 11e of the crimping sleeve 11A.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The present invention relates to a fixing member for an optical connector. [Background technology]

[0002] An optical connector is attached to the end of an optical cable. In addition to the optical fiber, a tension body that resists tension acting on the optical cable during installation is also stored inside the sheath of the optical cable so that the tension does not act on the optical fiber. Tensile fibers, such as aramid fibers, are often used as the tension body. In order to prevent tension from acting on the optical fiber, it is necessary to fix the tensile fiber to the optical connector. The work of attaching an optical connector to the end of an optical cable is often performed at the optical cable installation site, and good workability is required.

[0003] The following Patent Document 1 discloses a fixing member for an optical connector. First, an optical cable is fixed to this fixing member, and then this fixing member is fixed to a housing of an optical connector, thereby attaching the optical connector to the end of the optical cable. The fixing member disclosed in Patent Document 1 aims to realize improvement of workability when attaching an optical connector to an optical cable on-site, in particular, workability when fixing a tensile strength fiber to an optical connector.

[0004] The fixing member disclosed in Patent Document 1 includes a first and a second member. The first member has a cylindrical portion through which an optical fiber is inserted, and a male thread portion is formed on the outer periphery of this cylindrical portion. The second member is a cylindrical member having a female thread portion formed on the inner periphery, which is screwed with the male thread portion. When the female thread portion of the second member is screwed into the male thread portion of the first member, a tensile strength fiber extending from an edge of the sheath of the optical cable is sandwiched between the first member and the female thread portion, whereby the tensile strength fiber is fixed to the fixing member. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2009-104069 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the fixing member disclosed in Patent Document 1, the second member is rotated and screwed to the first member, so a certain amount of working space for fingertips is required around the fixing member. In addition, the fixing strength of the optical cable to the fixing member is determined by how much the second member is screwed to the first member, but it is difficult to know how far the second member should be screwed to obtain optimal fixing strength, i.e., how much it should be rotated. If the second member is rotated too much relative to the first member, the first member or the second member will be damaged, and if the rotation is insufficient, the fixing will be insufficient. If the optical cable is not fixed to the fixing member sufficiently, tension will be applied to the optical fiber in the optical cable.

[0007] An object of the present invention is to provide an optical connector fixing member that can properly fix an optical cable and has good workability. [Means for solving the problem]

[0008] The optical connector fixing member of the present invention is used when attaching an optical connector to an optical cable in which a tensile strength fiber is interposed between an optical fiber and a sheath, and includes a crimp sleeve having a cylindrical shape into which the optical fiber extending from the tip edge of the sheath of the optical cable is inserted and whose base end insertion portion is pressed into the inside of the sheath from the tip edge of the sheath, an inner ring having a cylindrical shape and sliding along the optical cable to clamp the tensile strength fiber extending from the tip edge of the sheath between the extension portion of the crimp sleeve extending from the tip edge of the sheath, and an outer ring having a cylindrical shape and sliding along the optical cable to clamp the tensile strength fiber extending from the tip edge of the sheath and the inner ring between the extension portion of the crimp sleeve by its tip portion, and to clamp the tensile strength fiber, the sheath, and the inner ring located inside the tip edge of the sheath, between the base end of the crimp sleeve by its base end. Effect of the Invention

[0009] The optical connector fixing member according to the present invention provides good workability and allows an optical cable to be properly fixed to an optical connector. [Brief description of the drawings]

[0010] [Figure 1] 1 is a perspective view showing an optical connector to which an optical connector fixing member according to an embodiment is attached and a mating connector to be connected to the optical connector; [Diagram 2] FIG. 2 is an exploded perspective view of the optical connector and the mating connector. [Diagram 3] 2 is a cross-sectional view of the optical connector and the mating connector. FIG. [Figure 4] FIG. 2(a) is a side view showing a step (first step) of attaching an optical connector to an optical cable, and FIG. 2(b) is a side view showing the above attachment step (second step). [Diagram 5]FIG. 1(a) is a side view showing a step (third step) of attaching an optical connector to an optical cable, and FIG. 1(b) is a side view showing the above attachment step (fourth step). [Figure 6] FIG. 13(a) is a side view showing a step (fifth step) of attaching an optical connector to an optical cable, and FIG. 13(b) is a side view showing the above attachment step (sixth step). [Figure 7] FIG. 13(a) is a side view showing a step (seventh step) of attaching an optical connector to an optical cable, and FIG. 13(b) is a side view showing the above attachment step (eighth step). [Figure 8] FIG. 2 is an enlarged cross-sectional view of a main portion of the optical connector. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] An optical connector fixing member according to an embodiment (hereinafter, simply referred to as fixing member 11) will be described with reference to the drawings. Note that "up, down, left, right" in the following description refers to up, down, left, right in the drawings for the purpose of explanation, and does not limit the orientation in which fixing member 11 is installed.

[0012] The optical connector 1 in FIG. 1 to which the fixing member 11 of this embodiment is attached is a female connector. FIG. 1 shows a connection state between the optical connector 1 and a mating connector 2 to which the optical connector 1 is connected. The mating connector 2 is a male connector. Two optical cables 3 are attached to the optical connector 1 shown in FIG. 1. In other words, the optical connector 1 is attached to the ends of the two optical cables 3, and the ends of the optical cables 3 are located inside a resin housing 4 of the optical connector 1. The mating connector 2 is mounted on a printed circuit board (PCB). The mating connector 2 includes a resin housing 5 and a metal shield case 6. A plurality of protrusions used for fixing the mating connector 2 to the PCB protrude downward from the lower edge of the shield case 6.

[0013] FIG. 2 shows an exploded perspective view of the optical connector 1 and the mating connector 2. A pair of photoelectric conversion components 7 are housed inside the mating connector 2. One of the photoelectric conversion components 7 is for transmitting, and the other is for receiving. The photoelectric conversion components 7 are electrically connected to a circuit on a PCB. As shown in FIG. 3, each optical cable 3 to which the optical connector 1 is attached has an optical fiber 8 at its center, and its outer periphery is covered with a sheath 9. A large number of tensile fibers 10, specifically aramid fibers, are interposed between the optical fiber 8 and the sheath 9.

[0014] As will be explained in detail later, at the end of the optical cable 3, a predetermined length of the sheath 9 is removed to expose the optical fiber 8. Then, the tensile strength fiber 10 extending from the cut end of the sheath 9 is fixed to the optical connector 1 by a fixing member 11. The fixing member 11 includes a crimp sleeve 11A, an inner ring 11B, and an outer ring 11C. The crimp sleeve 11A, the inner ring 11B, and the outer ring 11C are resin molded products. A ferrule 12 is attached to the tip of the optical fiber 8. The ferrule 12 is fixed to the tip of the optical fiber 8 by adhesive.

[0015] Then, the crimp sleeve 11A is fixed to the housing 4 of the optical connector 1, whereby the tensile strength fibers 10 of the optical cable 3 are fixed to the optical connector 1. The crimp sleeve 11A is fixed to the housing 4 by fitting a stopper 13 to the bottom surface of the housing 4. When the stopper 13 is fitted to the housing 4, a tip flange 11d formed at the tip of the crimp sleeve 11A is fixed to the housing 4 by the stopper 13, a protrusion 14 protruding into the housing 4, and a spring 15 attached to the stopper 13. That is, the crimp sleeve 11A can be fixed to the housing 4 simply by fitting the stopper 13 to the bottom surface of the housing 4.

[0016] When the stopper 13 is fitted into the housing 4, the above-mentioned spring 15 is also attached inside the housing 4. The spring 15 engages with a flange formed in the axial center of the ferrule 12, and urges the ferrule 12 toward the tip of the optical fiber 8. The ferrule 12 urged by the spring 15 abuts against the inner surface of the housing 4, and the tip of the optical fiber 8 is positioned at a predetermined position. In addition, when the optical connector 1 is connected to the mating connector 2, the spring 15 also has the function of urging the end face of the ferrule 12, i.e., the end face of the optical fiber 8, so as to be pressed against a predetermined portion of the photoelectric conversion component 7.

[0017] By fixing the optical cable 3 to the crimp sleeve 11A fixed to the housing 4 in this manner, the optical cable 3 is fixed to the housing 4, i.e., the optical connector 1. An inner ring 11B and an outer ring 11C are used to fix the crimp sleeve 11A to the optical cable 3. That is, a fixing member 11 including the crimp sleeve 11A, the inner ring 11B and the outer ring 11C is fixed to the end of the optical cable 3. The manner in which the fixing member 11 is fixed to the end of the optical cable 3 will be described with reference to the fixing steps shown in Figs. 4 to 7.

[0018] In addition, in this description, the cross-sectional view of FIG. 8 is also referred to. FIG. 8 shows a state in which the fixing member 11 is fixed to the optical cable 3. In FIG. 8, the deformation between the members is partially omitted, and the members are shown overlapping each other. For example, the tensile strength fiber 10 is sandwiched between the crimp sleeve 11A and the sheath 9, but the deformation of the relevant portion is not shown accurately, but is shown linearly. In addition, the cross section of the upper half in FIG. 8 is a cross section at the guide groove 11m of the inner ring 11B described later, and the cross section of the lower half in FIG. 8 is a cross section at the guide groove 11m of the inner ring 11B described later and a cross section at the tip side slit 11k.

[0019] When fixing the fixing member 11 to the optical cable 3, first, the optical cable 3 cut to a predetermined length is prepared, as shown in Fig. 4(a). At this time, the optical fiber 8, the sheath 9, and the tensile strength fiber 10 are all cut together at the end (right side in the figure) of the optical cable 3. Next, as shown in Fig. 4(b), the outer ring 11C and the inner ring 11B are passed through the optical cable 3 in this order in advance. The inner ring 11B is positioned closer to the tip of the optical cable 3.

[0020] Next, as shown in Fig. 5(a), a part of the tip of the sheath 9 is cut off, and the optical fiber 8 and the tensile strength fiber 10 are extended from the tip edge of the sheath 9. Next, as shown in Fig. 5(b), the tensile strength fiber 10 extended from the tip edge of the sheath 9 is cut to an appropriate length, and the tensile strength fiber 10 is withdrawn to the side in the axial direction (or in the opposite direction to the tip of the optical fiber 8), to expose the optical fiber 8. As a result, at the tip edge of the sheath 9, the tensile strength fiber 10 inside the sheath 9 is moved from the center of the sheath 9 to the inner circumferential surface.

[0021] Next, as shown in FIG. 6(a), the proximal end insertion portion 11e (see FIG. 8) of the crimp sleeve 11A is inserted into the inside of the sheath 9 from the distal end edge. In the state shown in FIG. 6(a), the proximal end insertion portion 11e of the crimp sleeve 11A is already inserted into the inside of the sheath 9. The crimp sleeve 11A has a cylindrical shape, and the optical fiber 8 is inserted into the inside of the crimp sleeve 11A and extends from the distal end side of the crimp sleeve 11A. As shown in FIG. 8, the reference outer diameter of the proximal end insertion portion 11e is approximately the same as the reference inner diameter of the sheath 9. A plurality of annular protrusions 11f are formed on the outer peripheral surface of the proximal end insertion portion 11e, and the outer diameter of the annular protrusions 11f is larger than the reference inner diameter of the sheath 9. However, the outer diameter of the annular protrusions 11f is large enough to press the proximal end insertion portion 11e into the inside of the sheath 9. Therefore, when the base end insertion portion 11e is inserted into the sheath 9 from the tip edge thereof, the annular protrusion 11f bites into the sheath 9. As a result, the base end insertion portion 11e is fixed to the end of the sheath 9. At this time, the tensile strength fiber 10 is sandwiched between the base end insertion portion 11e and the inner peripheral surface of the sheath 9. Since the base end insertion portion 11e has the annular protrusion 11f, the tensile strength fiber 10 is more firmly sandwiched by the annular protrusion 11f. The annular protrusion 11f has an inverted claw-shaped triangular cross section so that it can be easily press-fitted into the sheath 9 and is difficult to come out of the sheath 9.

[0022] Next, as shown in Fig. 6(b), the inner ring 11B is slid along the optical cable 3 and is placed over the extension portion 11g (see Fig. 8) of the crimp sleeve 11A extending from the tip edge of the sheath 9. As shown in Fig. 8, a flange 11h is formed on the extension portion 11g, and the tip edge of the inner ring 11B abuts against the flange 11h, so that the inner ring 11B stops at an appropriate sliding position.

[0023] In addition, a plurality of annular projections 11i are also formed on the base end side (left side in FIG. 8) of the extension portion 11g. The outer diameter of the annular projection 11i on the base end side is made sufficiently larger than the reference inner diameter of the sheath 9. "Sufficiently large" here means that the annular projection 11i cannot be press-fitted inside the sheath 9. When the base end insertion portion 11e of the crimp sleeve 11A is inserted into the sheath 9, the annular projection 11i abuts against the tip edge of the sheath 9 via the tensile strength fiber 10, so that the insertion position of the crimp sleeve 11A into the sheath 9 is appropriate. In other words, the crimp sleeve 11A has a structure in which the distance between the tip edge of the sheath 9 and the flange 11h is constant.

[0024] The inner ring 11B has four distal intermittent cylindrical portions 11j that fit between the distal end edge of the sheath 9 and the flange 11h (see FIG. 5(a) and the upper side of FIG. 8). The distal intermittent cylindrical portions 11j are arranged evenly in the circumferential direction and in a cylindrical shape as a whole. A distal slit 11k is formed between adjacent distal intermittent cylindrical portions 11j (see FIG. 6(b) and the lower side of FIG. 8). The distal slit 11k reaches the distal end edge of the inner ring 11B. An inverted claw-shaped protrusion 11l is formed on the inner surface of the distal intermittent cylindrical portion 11j (see the upper side of FIG. 8). The height of the multiple annular protrusions 11i on the above-mentioned extension portion 11g is lowered toward the distal end side (the right side in FIG. 8) in accordance with the shape of the protrusion 11l. A guide groove 11m is formed in the axial direction on the outer surface of the distal intermittent cylindrical portion 11j (see FIG. 6(b) and the upper side of FIG. 8).

[0025] The inner ring 11B has a base end side interrupted cylindrical portion 11n in a portion overlapping with the sheath 9 (see FIG. 5(a) and the lower side of FIG. 8). The base end side interrupted cylindrical portion 11n is formed in four portions evenly spaced in the circumferential direction and is arranged in a cylindrical shape as a whole. A base end side slit 11p is formed between adjacent base end side interrupted cylindrical portions 11n (see FIG. 6(b) and the upper side of FIG. 8). The base end side slit 11p reaches the base end edge of the inner ring 11B. The circumferential position of the base end side interrupted cylindrical portion 11n coincides with the circumferential position of the tip end side slit 11k described above (cross section in the lower side of FIG. 8). The circumferential position of the base end side slit 11p coincides with the circumferential position of the tip end side interrupted cylindrical portion 11j (cross section in the upper side of FIG. 8). Here, both side edges of each base end side interrupted cylindrical portion 11n are continuous with the side edges of a pair of adjacent tip end side interrupted cylindrical portions 11j, respectively. Therefore, the distal end side interrupted cylindrical portion 11j and the proximal end side interrupted cylindrical portion 11n are alternately arranged in the circumferential direction and are continuous, forming a cylindrical inner ring 11B as a whole.

[0026] In the inner ring 11B having such a structure, the tip side slits 11k formed from the tip edge and the base side slits 11p formed from the base edge are formed alternately in the circumferential direction. With this structure, the inner ring 11B can elastically expand in diameter due to its own elastic restoring property. Therefore, the inner ring 11B can be retained in the sheath 9 in an expanded state as shown in Figs. 4(a) to 6(b). The inner ring 11B retained in the sheath 9 tries to reduce in diameter due to its own elastic restoring force, so it does not slide along the optical cable 3 by itself, and the workability at the site is good. In addition, a protrusion 11o is formed on the inner surface of the base side interrupted cylinder portion 11n (see the lower side of Fig. 8). The protrusion 11o will be described later.

[0027] Next, as shown in FIG. 7(a), the outer ring 11C is slid along the optical cable 3 and is placed over the tip of the sheath 9 and the inner ring 11B. As shown in FIG. 8, the tip edge of the outer ring 11C also abuts against the flange 11h, so that the outer ring 11C stops at an appropriate sliding position. Four guide ribs 11q are formed on the inner surface of the outer ring 11C at equal intervals in the circumferential direction (see FIG. 6(b) and the upper side of FIG. 8). When the outer ring 11C slides, the tip of the guide rib 11q is first inserted into the base end slit 11p to guide the sliding. The width of the base end of the base end slit 11p is tapered to make it easy to receive the guide rib 11q. If the position of the guide rib 11q does not match the position of the base end slit 11p, the outer ring 11C cannot be slid onto the inner ring 11B. In other words, the guide rib 11q and the base end slit 11p also function as a mechanism for adjusting the rotational position of the outer ring 11C relative to the inner ring 11B.

[0028] When the outer ring 11C is further slid, the tip side of the guide rib 11q is accommodated in the guide groove 11m formed on the outer circumferential surface of the tip side interrupted tubular portion 11j of the inner ring 11B. The base end slit 11p and the guide groove 11m are continuous in the axial direction, and their inner width is approximately equal to the guide rib 11q. The tip edge of the guide rib 11q is tapered to make it easy to insert into the guide groove 11m. The guide rib 11q accommodated in the guide groove 11m slightly presses the tip side interrupted tubular portion 11j of the inner ring 11B inward. This allows the tensile strength fiber 10 sandwiched between the annular protrusion 11i formed on the outer circumferential surface of the extension portion 11g of the crimp sleeve 11A and the protrusion 11l formed on the inner circumferential surface of the tip side interrupted tubular portion 11j to be more firmly sandwiched.

[0029] Between adjacent guide ribs 11q, a locking piece 11r for locking the outer ring 11C to the crimp sleeve 11A is formed (see FIG. 6(b) and the lower side of FIG. 8). An inverted locking claw is formed at the tip of the locking piece 11r and protrudes inward. A U-shaped slit is formed around the locking piece 11r, and the locking piece 11r extends axially toward the tip side. This allows the locking piece 11r to be elastically deformed. Between the annular projection 11i and the flange 11h on the extension portion 11g of the crimp sleeve 11A, a locking flange 11s for locking with the locking piece 11r is formed (see FIG. 6(a) and the lower side of FIG. 8).

[0030] When the outer ring 11C is placed on the sheath 9, the tip of the locking claw of the locking piece 11r comes into contact with the surface of the sheath 9, and the locking piece 11r is bent outward. Since the locking piece 11r tries to return to its original shape by its own elastic restoring force, the outer ring 11C does not slide along the optical cable 3 on its own, and the workability at the site is good. When the outer ring 11C is slid, the tip of the locking claw of the locking piece 11r abuts against the base end edge of the base end side interrupted tubular portion 11n and is further bent outward, and the locking claw finally overcomes the base end side interrupted tubular portion 11n. At this time, the tip of the locking piece 11r is formed in a tapered shape so that the locking piece 11r can be easily deformed outward, and the base end edge of the inner ring 11B is also formed in a tapered shape. The locking claw of the locking piece 11r that has climbed over the base end side interrupted cylindrical portion 11n is housed in the tip end side slit 11k of the inner ring 11B, and the locking piece 11r returns to its original shape.

[0031] When the outer ring 11C is further slid, its leading edge abuts against the flange 11h, and the locking claws of the locking pieces 11r overcome the locking flange 11s and lock with the locking flange 11s. This lock fixes the outer ring 11C and the crimp sleeve 11A to each other. Also, the base end of the outer ring 11C presses the base end side interrupted tubular portion 11n of the inner ring 11B inward, and the protrusions 11o formed on the inner surface of the base end side interrupted tubular portion 11n bite into the sheath 9. This firmly fixes the inner ring 11B to the sheath 9. At the same time, the sheath 9 is also pressed inward by the bite of the protrusions 11o. As a result, the tensile strength fiber 10 sandwiched between the annular protrusions 11f formed on the outer peripheral surface of the base end insertion portion 11e of the crimp sleeve 11A and the inner peripheral surface of the sheath 9 is more firmly sandwiched.

[0032] Next, a ferrule 12 is attached to the tip of the optical fiber 8 with an adhesive, and the tip surface is polished. Finally, as shown in Fig. 7(b), the fixing member 11 is fixed to the housing 4. The fixing member 11 is fixed to the housing 4 by fitting the stopper 13 to the housing 4 as described above. By constructing the structure shown in Fig. 8, the tensile strength fiber 10 of the optical cable 3 can be firmly fixed to the fixing member 11 by the crimp sleeve 11A, the inner ring 11B, and the outer ring 11C of the fixing member 11 attached to the end of the optical cable 3.

[0033] Furthermore, the fixing operation is very simple, such as pressing in the crimp sleeve 11A and sliding the inner ring 11B and the outer ring 11C, and is easy to perform on-site, with excellent workability. Also, there is no need for fingertip space to pinch and rotate as in the above-mentioned Patent Document 1, and it is only necessary to slide the inner ring 11B and the outer ring 11C. Also, there is no need for a difficult-to-perform-on-site operation such as fusion to fix the optical connector 1 to the end of the optical cable 3.

[0034] Since the tensile strength fibers 10 of the optical cable 3 are fixed to the fixing member 11, and the fixing member 11 is fixed to the optical connector 1, even if a tensile force acts on the optical cable 3, the tensile force is received by the optical connector 1 via the fixing member 11 and does not act on the optical fiber 8. More specifically, as shown in Fig. 8, when such a tensile force acts on the optical cable 3, the tensile force acts on the tensile strength fibers 10. At this time, the crimp sleeve 11A of the fixing member 11 is fixed to the housing 4 of the optical connector 1, and the inner ring 11B is pulled to the left in the figure via the tensile strength fibers 10. As a result, the inverted claw-shaped protrusions 11l formed on the inner surface of the leading end side interrupted cylindrical portion 11j of the inner ring 11B are pressed against the annular protrusion 11i of the crimp sleeve 11A.

[0035] At this time, a force acts to expand the diameter of the inner ring 11B. As described above, the inner ring 11B has a structure that allows it to expand elastically, but in the state shown in Fig. 8, such expansion is suppressed by the outer ring 11C. Therefore, the protrusion 11l is pressed securely against the annular protrusion 11i, and the tensile strength fiber 10 sandwiched therebetween is held even more firmly. In other words, when a tensile force acts on the optical cable 3, the bond between the optical cable 3 and the fixing member 11 via the tensile strength fiber 10 is further strengthened.

[0036] The following describes the effects of the fixing member 11 according to the above embodiment.

[0037] The fixing member 11 according to the above embodiment is used when attaching the optical connector 1 to the optical cable 3 in which the tensile strength fiber 10 is interposed between the optical fiber 8 and the sheath 9. The fixing member 11 includes a crimp sleeve 11A, an inner ring 11B, and an outer ring 11C. The crimp sleeve 11A has a cylindrical shape into which the optical fiber 8 extending from the tip edge of the sheath 9 of the optical cable 3 is inserted, and its base end insertion portion 11e is press-fitted into the sheath 9 from the tip edge of the sheath 9. The inner ring 11B has a cylindrical shape, and by sliding along the optical cable 3, the tensile strength fiber 10 extending from the tip edge of the sheath 9 is sandwiched between the crimp sleeve 11A and an extension portion 11g extending from the tip edge of the sheath 9 of the crimp sleeve 11A. The outer ring 11C has a cylindrical shape, and is slid along the optical cable 3 so that its distal end clamps the tensile strength fiber 10 extending from the distal end edge of the sheath 9 and the inner ring 11B between itself and the extending portion 11g of the crimp sleeve 11A. In addition, the outer ring 11C clamps the tensile strength fiber 10 located inside the distal end edge of the sheath 9, the sheath 9, and the inner ring 11B between itself and the proximal end insertion portion 11e of the crimp sleeve 11A.

[0038] Therefore, according to the fixing member 11 according to the above embodiment, the tensile strength fiber 10 of the optical cable 3 is sandwiched together with the sheath 9 and the inner ring 11B between the base end insertion portion 11e of the crimp sleeve 11A and the outer ring 11C. At the same time, the tensile strength fiber 10 is sandwiched together with the inner ring 11B between the extension portion 11g of the crimp sleeve 11A and the outer ring 11C. When the fixing member 11 is fixed to the optical connector 1, the tensile strength fiber 10 of the optical cable 3 is fixed to the optical connector 1. Therefore, even if a tensile force acts on the optical cable 3, the tensile strength fiber 10 is received by the tensile strength fiber 10 fixed to the optical connector 1 via the fixing member 11, and does not act on the optical fiber 8 in the optical cable 3.

[0039] When constructing the above-mentioned fixed form, in addition to inserting the base end insertion portion 11e of the crimp sleeve 11A into the sheath 9, it is only necessary to slide the inner ring 11B and the outer ring 11C along the optical cable 3, which makes the workability at the site good. Also, since the fixing is by sliding, not by screwing as in the above-mentioned Patent Document 1, the fixing strength does not change depending on the amount of rotation for screwing. Also, there is no risk of damaging the parts. Also, a troublesome process such as fusion is not required.

[0040] Furthermore, according to the fixing member 11 of the embodiment, the extension portion 11g of the crimp sleeve 11A is provided with a flange 11h that abuts against the leading edge of the slid inner ring 11B and the leading edge of the slid outer ring 11C. This makes it easy to set the crimp sleeve 11A and the inner ring 11B to a predetermined sliding position, which also improves workability on site.

[0041] Moreover, according to the fixing member 11 of the above embodiment, a protrusion 11o is formed that protrudes toward the sheath 9 from the inner peripheral surface of the overlapping portion of the inner ring 11B with the sheath 9. The inner ring 11B is pressed from the outside by the outer ring 11C, so the protrusion 11o bites into the sheath 9. This prevents the inner ring 11B from being displaced in the axial direction. In addition, the protrusion 11o bites into the sheath 9, so that the tensile strength fiber 10 between the sheath 9 and the base end insertion portion 11e of the crimp sleeve 11A can be more reliably clamped. Furthermore, the formation of the protrusion 11o prevents the inner ring 11B in a standby state from sliding freely into the sheath 9 portion, improving workability on site.

[0042] Moreover, according to the fixing member 11 according to the embodiment, at least one annular protrusion 11f having an outer diameter larger than the reference inner diameter of the sheath is formed on the outer peripheral surface of the base end insertion portion 11e of the crimp sleeve 11A. This prevents the crimp sleeve 11A from coming off the sheath 9, and more reliably holds the tensile strength fiber 10 between the sheath 9 and the base end insertion portion 11e. In particular, if the above-mentioned protrusion 11o is formed, the sheath 9 is pressed against the outer peripheral surface of the base end insertion portion 11e on which the unevenness is formed by the annular protrusion 11f, so that the crimp sleeve 11A is more reliably prevented from coming off the sheath 9. Furthermore, if the above-mentioned protrusion 11o is formed, the sheath 9 is pressed against the outer peripheral surface of the base end insertion portion 11e on which the unevenness is formed by the annular protrusion 11f, so that the tensile strength fiber 10 between the sheath 9 and the base end insertion portion 11e can be more reliably held.

[0043] Moreover, according to the fixing member 11 of the above embodiment, at least one annular protrusion 11i having an outer diameter sufficiently larger than the reference inner diameter of the sheath 9 is formed on the outer peripheral surface of the extension portion 11g of the crimp sleeve 11A. "Sufficiently large" here means that the annular protrusion 11i cannot be press-fitted into the inside of the sheath 9. Therefore, the annular protrusion 11i can regulate the insertion amount of the base end insertion portion 11e of the crimp sleeve 11A into the inside of the sheath 9, and the crimp sleeve 11A can be set at an appropriate position with respect to the optical cable 3. Moreover, the tensile strength fiber 10 sandwiched between the inner ring 11B and the extension portion 11g is pressed by the inner ring 11B against the outer peripheral surface of the extension portion 11g on which the unevenness is formed by the annular protrusion 11i, so that the tensile strength fiber 10 can be more reliably sandwiched.

[0044] Although the present embodiment has been described above, the present embodiment is not limited thereto, and various modifications are possible within the scope of the present embodiment. For example, in the above embodiment, the annular protrusions 11f and 11i are formed continuously around the entire circumference. However, they may be formed in an annular shape intermittently in the circumferential direction. [Explanation of symbols]

[0045] 1 Optical Connector 3. Optical Cable 8. Optical Fiber 9. Sheath 10 Tensile Fibers 11 Fixing member 11A Crimp Sleeve 11B Inner ring 11C Outer Ring 11e Base end insertion part 11f Ring protrusion 11g extension 11h flange 11i Ring protrusion 11o protrusion

Claims

1. An optical connector fixing member used when attaching an optical connector to an optical cable having an optical fiber and a sheath having a tensile strength fiber interposed therebetween, a crimp sleeve having a tubular shape into which the optical fiber extending from the tip edge of the sheath of the optical cable is inserted, and a base end insertion portion of the crimp sleeve is press-fitted into the inside of the sheath from the tip edge of the sheath; an inner ring having a cylindrical shape, which is slid along the optical cable to sandwich the tensile strength fiber extended from the tip edge of the sheath between the inner ring and an extension portion of the crimp sleeve extended from the tip edge of the sheath; a cylindrical outer ring that is slid along the optical cable to clamp, with its tip end, the tensile fiber extending from the tip edge of the sheath and the inner ring between the extension portion of the crimp sleeve, and, with its base end, clamps, with the tensile fiber located inside the tip edge of the sheath, the sheath, and the inner ring between the base end insertion portion of the crimp sleeve.

2. 2. The optical connector fixing member according to claim 1, wherein the crimp sleeve has a flange provided on the extension portion that abuts against a leading edge of the slid inner ring and a leading edge of the slid outer ring.

3. 2. The optical connector fixing member according to claim 1, wherein a protrusion is formed protruding from an inner circumferential surface of the overlapping portion of said inner ring with said sheath toward said sheath.

4. 4. The optical connector fixing member according to claim 2, wherein at least one annular projection having an outer diameter larger than a reference inner diameter of said sheath is formed on an outer peripheral surface of said base end insertion portion of said crimp sleeve.

5. 3. The optical connector fixing member according to claim 2, wherein at least one annular projection having an outer diameter sufficiently larger than a reference inner diameter of said sheath is formed on an outer peripheral surface of said extended portion of said crimp sleeve.

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