Optical connector

Abstract

To allow the impression of being difficult to use to be eliminated or reduced in an optical connector equipped with a square cylindrical housing in which a slit for inserting an optical fiber cable is formed.SOLUTION: A housing 7 of a jack 2, which is an optical connector, includes: a female connecting portion 8 which is formed in the front portion of the housing 7 and the inside of which a male connecting portion of a mating optical connector is inserted into and connected to; a square cylindrical grip portion 9 which is formed in the rear portion of the housing 7 and is a portion for gripping the housing 7; a ferrule accommodating portion which is formed inside the housing 7 and accommodates a ferrule 3; a cable insertion portion which is formed at the rear end portion of the housing 7 and through which an optical fiber cable 91 with the ferrule 3 attached is inserted; and a slit 14 which is formed at a corner of the peripheral wall of the housing 7 and for inserting the optical fiber cable 91 into the housing 7.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an optical connector used for forming an optical transmission path. [Background Art]

[0002] An optical connector is a connector that connects two optical fiber cables to each other to form an optical transmission path. When connecting two optical fiber cables to each other, one optical connector is attached to the distal end of one optical fiber cable, another optical connector is attached to the distal end of the other optical fiber cable, and the one optical connector and the other optical connector are connected to each other. Hereinafter, when connecting two optical fiber cables to each other, the one optical connector attached to the distal end of one optical fiber cable is referred to as an "optical connector", and the other optical connector attached to the distal end of the other optical fiber cable is referred to as a "mating optical connector".

[0003] The optical connector includes a housing that accommodates a ferrule to which an optical fiber cable is attached. The housing is formed into a cylindrical shape from, for example, a resin material, and a connection portion to be connected to a mating optical connector is formed at the distal end portion of the housing. A grip portion, where an operator grips the housing with fingers when connecting the optical connector to the mating optical connector, is formed at the proximal end portion of the housing.

[0004] Further, in some optical connector housings, the opening on the distal end side of the housing has a diameter larger than the maximum outer diameter of the ferrule, and the opening on the proximal end side of the housing has a diameter larger than the outer diameter of the optical fiber cable and smaller than the maximum outer diameter of the ferrule. In such a housing, when assembling the optical connector, an operator can insert the ferrule into the housing through the opening on the distal end side of the housing and place the ferrule inside the housing.

[0005] Furthermore, some optical connector housings have slits formed in their peripheral walls. In the optical connector described in Japanese Patent Publication No. 1-116604 (Patent Document 1), slits are formed in the peripheral wall of the housing (knob). The slits extend from the tip to the base of the housing. By forming slits in the peripheral wall of the housing, a portion of the peripheral wall of the housing is cut off. The width of the slits is set to be larger than the outer diameter of the optical fiber cable and smaller than the maximum outer diameter of the ferrule. When placing a ferrule with an optical fiber cable attached into the housing, the worker first passes the optical fiber cable with the ferrule attached through the slit and inserts it into the housing, and then inserts the ferrule with the optical fiber cable attached into the housing from the opening on the tip side of the housing. Because slits are formed in the housing, the worker can easily place a ferrule with an optical fiber cable attached into the housing.

[0006] Incidentally, because optical connectors are small, their housings are also small and light. Therefore, when the housing (knob) is formed in a cylindrical shape, as in the optical connector described in Japanese Patent Publication No. 1-116604, when the optical connector is disassembled, the housing is likely to roll off the work table and fall to the floor, accumulating dust on the floor or even getting lost. In this regard, Japanese Patent Publication No. 2017-187571 (Patent Document 2) describes an optical connector equipped with a square cylindrical housing. A square cylindrical housing is less likely to roll than a cylindrical housing. Therefore, by forming the housing in a square cylindrical shape, it is possible to suppress the housing from rolling and falling. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 1-116604 [Patent Document 2] Japanese Patent Publication No. 2017-187571 [Overview of the project] [Problems that the invention aims to solve]

[0008] In the optical connector described in Japanese Patent Publication No. 2017-187571, the housing is formed in the shape of a rectangular tube, and a slit is formed in the peripheral wall of the housing. As shown in Figure 8 of the said publication, the slit is formed in the center in the width direction of one of the four plate-shaped wall portions that constitute the peripheral wall of the rectangular tube housing.

[0009] When a slit is formed in the center of the width direction of the wall of a rectangular cylindrical housing, the following problems arise.

[0010] Figures 14(A) and 14(B) show how an operator holds an optical connector 181, which has a housing 182 having the same shape as the housing of the optical connector described in Japanese Patent Publication No. 2017-187571. As shown in Figure 14(A) or 14(B), when connecting the optical connector 181 to a mating optical connector, the operator holds the housing 182 of the optical connector 181 with, for example, their thumb and index finger. At this time, as shown in Figure 14(A), either the operator's thumb or index finger may be in contact with the outer surface of the wall portion of the rectangular tubular housing 182 of the optical connector 181 where the slit 183 is not formed, or as shown in Figure 14(B), the operator's thumb (or index finger) may be in contact with the outer surface of the wall portion of the housing 182 of the optical connector 181 where the slit 183 is formed.

[0011] When a worker's thumb (or index finger) touches the outer surface of the wall portion of the housing 182 of the optical connector 181 where the slit 183 is formed, as shown in Figure 14(B), the worker's thumb (or index finger) touches the portion of the outer surface of the wall portion where the slit 183 is open. The portion of the outer surface of the wall portion of the housing 182 where the slit 183 is open is uneven due to the opening of the slit 183. Therefore, when a worker's thumb (or index finger) touches the portion of the outer surface of the wall portion of the housing 182 where the slit 183 is open, the worker may feel discomfort and get the impression that the optical connector 181 is difficult to use.

[0012] Furthermore, if a worker's thumb (or index finger) touches the outer surface of the wall of the housing 182 where the slit 183 is open, the worker may feel uneasy that touching the opening of the slit 183 with their finger could cause debris to enter the housing 182 through the slit 183. Due to such anxieties, workers may develop the impression that the optical connector 181 is difficult to use.

[0013] The present invention has been made in view of the problems described above, for example, and the object of the present invention is to provide an optical connector that has a rectangular tubular housing with a slit formed therein for inserting an optical fiber cable, and that can eliminate or reduce the impression of being difficult to use. [Means for solving the problem]

[0014] To solve the above problems, the present invention provides an optical connector comprising a cylindrical housing for housing a ferrule attached to an optical fiber cable, wherein the housing comprises a connection portion formed on one axial side of the housing, opening on the axial side, into which a part of a mating optical connector is inserted and connected; a gripping portion formed on the other axial side of the housing, which is a portion for gripping the housing; a ferrule housing portion formed inside the housing for housing the ferrule; a cable insertion portion formed on the other axial end of the housing, opening on the other axial side, for inserting the optical fiber cable to which the ferrule is attached; and a slit formed in the peripheral wall of the housing, extending through the peripheral wall of the housing in the axial direction of the housing, for inserting the optical fiber cable into the housing, wherein the gripping portion is formed in a rectangular cylindrical shape. The outer circumferential surface of the gripping portion has a first plane, a second plane located on the outer circumferential surface of the gripping portion opposite to the portion where the first plane is located, a third plane located between one widthwise edge of the first plane and one widthwise edge of the second plane, and a fourth plane located between the other widthwise edge of the first plane and the other widthwise edge of the second plane, and the slit is open at the boundary between the first plane and the fourth plane, the boundary between the third plane and the first plane, the boundary between the second plane and the third plane, or the boundary between the fourth plane and the second plane. It is characterized by the following:

[0015] Furthermore, in the optical connector of the present invention described above, A locking projection provided on the mating optical connector may be inserted into a locking hole formed in the peripheral wall of the connecting portion, which together with the locking projection constitutes a bayonet-type locking mechanism that prevents the optical connector and the mating optical connector from coming apart.

[0016] childIn this case, the connecting portion is formed in a cylindrical shape, two locking holes are formed in the peripheral wall of the connecting portion, the two locking holes are arranged at two locations 180 degrees apart on the peripheral wall of the connecting portion, each locking hole extends approximately 90 degrees in the circumferential direction along the peripheral wall of the connecting portion, a locking release portion is formed at one circumferential end of each locking hole, and a locking portion is formed at the other circumferential end of each locking hole, when the locking projection is positioned in the locking release portion within each locking hole, the optical connector and the mating optical connector are in a locking state, and when the optical connector is viewed from one axial side, the connection In the circumferential direction of the part, the position of one of the two lock holes is determined such that the lock portion of that one lock hole is located in the widthwise center of the first plane of the gripping part, and the position of the other lock hole is determined such that the lock portion of the other lock hole is located in the widthwise center of the second plane of the gripping part. Alternatively, when viewing the optical connector from one axial side, in the circumferential direction of the connecting part, the position of one of the two lock holes is determined such that the lock portion of that one lock hole is located in the widthwise center of the third plane of the gripping part, and the position of the other lock hole is determined such that the lock portion of the other lock hole is located in the widthwise center of the fourth plane of the gripping part. [Effects of the Invention]

[0017] According to the present invention, in an optical connector having a rectangular cylindrical housing with a slit formed for inserting an optical fiber cable, the impression of it being difficult to use can be eliminated or reduced. [Brief explanation of the drawing]

[0018] [Figure 1] This is an external view showing an optical connector device including an optical connector according to the first embodiment of the present invention. [Figure 2]It is a cross-sectional view showing the optical connector device cut along the cutting line II-II in FIG. 1. [Figure 3] It is a perspective view showing the external appearance of the optical connector according to the first embodiment of the present invention. [Figure 4] It is an exploded perspective view showing the optical connector according to the first embodiment of the present invention. [Figure 5] It is a cross-sectional view of the housing of the optical connector according to the first embodiment of the present invention, cut at the same position as in FIG. 2. [Figure 6] (A) is an external view showing the housing of the optical connector according to the first embodiment of the present invention as viewed from the front, and (B) is a cross-sectional view showing the housing of the optical connector according to the first embodiment of the present invention, cut along the cutting line VI-VI in FIG. 5. [Figure 7] It is a perspective view showing the external appearance of the front portion of the housing of the optical connector according to the first embodiment of the present invention. [Figure 8] It is a perspective view showing the external appearance of the mating optical connector. [Figure 9] It is an exploded perspective view showing the mating optical connector. [Figure 10] It is an explanatory view showing a connection method between the optical connector according to the first embodiment of the present invention and the mating optical connector. [Figure 11] It is an explanatory view showing how an operator holds the optical connector according to the first embodiment of the present invention. [Figure 12] (A) is a cross-sectional view showing the housing of the optical connector according to the second embodiment of the present invention, cut at the same position as in FIG. 6(B), (B) is a cross-sectional view showing the housing of the optical connector according to the third embodiment of the present invention, cut at the same position as in FIG. 6(B), and (C) is a cross-sectional view showing the housing of the optical connector according to the fourth embodiment of the present invention, cut at the same position as in FIG. 6(B). [Figure 13](A) is a cross-sectional view showing the housing of the optical connector of the first comparative example cut at the same position as in Figure 6(B), (B) is a cross-sectional view showing the housing of the optical connector of the second comparative example cut at the same position as in Figure 6(B), (C) is a cross-sectional view showing the housing of the optical connector of the third comparative example cut at the same position as in Figure 6(B), and (D) is a cross-sectional view showing the housing of the optical connector of the fourth comparative example cut at the same position as in Figure 6(B). [Figure 14] This is an explanatory diagram showing how a worker grasps a conventional optical connector. [Modes for carrying out the invention]

[0019] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0020] (Optical connector device) Figure 1 shows an optical connector device 1 including an optical connector of the first embodiment of the present invention. Figure 2 shows a cross-section of the optical connector device 1 cut along the cutting line II-II in Figure 1, viewed from below in Figure 1. The optical connector device 1 is a device that connects optical fibers to form an optical transmission path. The optical connector device 1 includes a jack-type optical connector 2 (hereinafter referred to as "jack 2") and a plug-type optical connector 31 (hereinafter referred to as "plug 31"). Jack 2 corresponds to the first embodiment of the optical connector of the present invention. Plug 31 corresponds to the mating optical connector, which is the optical connector to which the optical connector of the first embodiment of the present invention is connected. Jack 2 and plug 31 are detachable from each other. This allows for easy connection of the optical fiber 92 of optical fiber cable 91 and the optical fiber 96 of optical fiber cable 95, and also allows for easy separation of the two as needed.

[0021] (Jack) Figure 3 shows Jack 2 viewed from the upper right front. Figure 4 shows Jack 2 in a disassembled state. Figure 5 shows a cross-section of the housing 7 of Jack 2. The position of the cross-section of housing 7 in Figure 5 (cutting position) is the same as the position of the cross-section of optical connector device 1 in Figure 2. Also, the dashed line in Figure 5 indicates the components housed in housing 7. Figure 6(A) shows housing 7 viewed from the front, and Figure 6(B) shows the cross-section of housing 7 cut along the cutting line VI-VI in Figure 5, viewed from the front (left in Figure 5). Figure 7 shows the front part of Jack 2 viewed from the upper left front. Furthermore, in the description of Jack 2, when indicating the directions of up (Ud), down (Dd), front (Fd), back (Bd), left (Ld), and right (Rd), follow the arrows drawn in Figures 3 to 7.

[0022] Jack 2 is equipped with ferrule 3 and housing 7.

[0023] The ferrule 3 is attached to the tip end of the optical fiber cable 91. The optical fiber cable 91 is a single-core optical fiber and has an optical fiber 92, a primary sheath 93 covering the outer circumference of the optical fiber 92, and a secondary sheath 94 covering the outer circumference of the primary sheath 93 (see Figure 2).

[0024] As shown in Figure 4, the ferrule 3 has a capillary 4 and a capillary support portion 5. The capillary 4 is a member that supports and positions the optical fiber 92 and is formed of a ceramic such as zirconia, glass, or nickel. The capillary 4 is formed in a cylindrical shape, and a small-diameter hole passes through its center in the axial direction, as shown in Figure 2. The capillary support portion 5 is a member that supports the capillary 4. The capillary support portion 5 is formed in a cylindrical shape from a metal such as stainless steel or nickel. The capillary 4 is attached to the front end of the capillary support portion 5. In addition, a flange portion 6 is formed on the front end side of the capillary support portion 5. That is, the front end side of the capillary support portion 5 has a larger diameter compared to the other parts of the capillary support portion 5, and this larger diameter portion is the flange portion 6.

[0025] The tip portion of the optical fiber cable 91 is attached to the ferrule 3 with its primary and secondary sheathing 93 and 94 removed. As shown in Figure 2, the portion of the optical fiber cable 91 where the primary and secondary sheathing 93 and 94 have been removed (the portion where the optical fiber 92 is exposed) is placed inside the hole that penetrates the capillary 4. The portion of the optical fiber cable 91 where the primary and secondary sheathing 93 and 94 have not been removed is placed inside the hole formed in the center of the capillary support portion 5. The tip surface (front end surface) of the capillary 4 is, for example, mirror-polished into a dome shape, and the end face of the optical fiber 92 is exposed in its center.

[0026] The housing 7 of the jack 2 is a component that houses the ferrule 3 and is formed in a cylindrical shape from, for example, a resin material. As shown in Figure 3, a female connector 8 is formed on the front part (axial side) of the housing 7. The female connector 8 is the part into which the male connector 42 of the plug 31 is inserted when connecting the jack 2 and the plug 31. The female connector 8 is formed in a cylindrical shape and opens forward at the front end surface of the housing 7. The inner diameter of the female connector 8 is set to be approximately equal to the outer diameter of the male connector 42 (slightly larger than the outer diameter of the male connector 42) so that the male connector 42 fits into the female connector 8. Furthermore, the inner diameter of the female connector 8 is set to be larger than the maximum outer diameter of the ferrule 3 (outer diameter of the flange portion 6) so that the ferrule 3 can be inserted into the housing 7 and placed in the ferrule housing portion 11 when assembling the jack 2. Note that the female connector 8 is a specific example of a "connection portion".

[0027] Furthermore, a gripping portion 9 is formed on the rear side (the side opposite the axial direction) of the housing 7. The gripping portion 9 is the part that an operator or other person grips with their fingers when connecting the jack 2 and the plug 31. The gripping portion 9 is formed in the shape of a rectangular tube. Specifically, the gripping portion 9 has a rectangular (for example, square) shape on the outer circumference of its cross-section and a circular shape on the inner circumference of its cross-section.

[0028] The outer circumferential surface of the gripping portion 9 has an upper surface 9A, a lower surface 9B, a left surface 9C, and a right surface 9D. As shown in Figure 6(B), on the outer circumferential surface of the gripping portion 9, the lower surface 9B is located on the opposite side of the portion where the upper surface 9A is located, the left surface 9C is located between the left edge (one side in the width direction) of the upper surface 9A and the left edge of the lower surface 9B, and the right surface 9D is located between the right edge (the other side in the width direction) of the upper surface 9A and the right edge of the lower surface 9B. The upper surface 9A, lower surface 9B, left surface 9C, and right surface 9D are all flat except for the boundary portions between the upper surface 9A and the right surface 9D, the boundary portion between the left surface 9C and the upper surface 9A, the boundary portion between the lower surface 9B and the left surface 9C, and the boundary portion between the right surface 9D and the lower surface 9B. R-shaped surfaces are formed at the boundaries between the left surface 9C and the top surface 9A, the boundary between the bottom surface 9B and the left surface 9C, and the boundary between the right surface 9D and the bottom surface 9B. A slit 14, described later, is open at the boundary between the top surface 9A and the right surface 9D. The top surface 9A, bottom surface 9B, left surface 9C, and right surface 9D are each rectangular. The top surface 9A is an example of the "first plane," the bottom surface 9B is an example of the "second plane," the left surface 9C is an example of the "third plane," and the right surface 9D is an example of the "fourth plane."

[0029] Furthermore, as shown in Figure 5, a ferrule housing portion 11 is formed on the inner circumference side of the housing 7, behind the female connector portion 8. The ferrule housing portion 11 is the portion in which the ferrule 3 is housed. The cross-sectional shape of the ferrule housing portion 11 is circular. In addition, the inner diameter of the rear portion of the ferrule housing portion 11 is smaller than the inner diameter of the front portion of the ferrule housing portion 11, and a stepped portion 12 is formed between the front and rear portions of the ferrule housing portion 11. The inner diameter of the front portion of the ferrule housing portion 11 is set to be larger than the outer diameter of the flange portion 6. In this embodiment, the inner diameter of the front portion of the ferrule housing portion 11 is equal to the inner diameter of the female connector portion 8. Also, the inner diameter of the rear portion of the ferrule housing portion 11 is smaller than the outer diameter of the flange portion 6, and is set to be larger than the outer diameter of the portion behind the flange portion 6 in the capillary support portion 5.

[0030] Furthermore, a cable insertion portion 13 is formed on the inner circumference side of the housing 7, behind the ferrule housing portion 11. The cable insertion portion 13 is the portion through which the optical fiber cable 91 attached to the ferrule 3 is inserted. The cable insertion portion 13 is located at the rear end portion (the other axial end portion) of the housing 7 and opens to the rear on the rear end surface of the housing 7. The cross-sectional shape of the cable insertion portion 13 is circular, and the inner diameter of the cable insertion portion 13 is equal to the inner diameter of the rear portion of the ferrule housing portion 11.

[0031] As shown in Figure 3, a slit 14 for inserting the optical fiber cable 91 into the housing 7 is formed in the upper right corner of the peripheral wall of the housing 7. The slit 14 penetrates the upper right corner of the peripheral wall of the housing 7 radially. The slit 14 also extends linearly from the front end to the rear end of the housing 7, penetrating the upper right corner of the peripheral wall of the housing 7. Due to the formation of the slit 14, the upper right corner of the peripheral wall of the housing 7 is cut off. The slit 14 has a width that is larger than the diameter of the optical fiber cable 91 and smaller than the outer diameter of the flange portion 6 of the ferrule 3. The slit 14 also passes through the upper right corner of the gripping portion 9. The slit 14 opens at the boundary between the upper surface 9A and the right surface 9D of the gripping portion 9.

[0032] Furthermore, in the housing 7, two locking holes 15 are formed in the peripheral wall of the female connector 8. These locking holes 15, together with the locking projection 51 formed in the housing 41 of the plug 31, constitute a bayonet-type locking mechanism that prevents the jack 2 and plug 31, which are connected to each other, from coming loose. As shown in Figure 3, each locking hole 15 is located approximately in the middle of the female connector 8 in the front-to-back direction. Also, as shown in Figure 5, each locking hole 15 penetrates the peripheral wall of the female connector 8 in the radial direction.

[0033] Furthermore, as shown in Figure 6(B), the two lock holes 15 are located at two different locations on the circumferential wall of the female connector 8, 180 degrees apart. Each lock hole 15 extends approximately 90 degrees circumferentially along the circumferential wall of the female connector 8. Also, as shown in Figures 6(B) and 7, a release portion 16 is formed at one circumferential end of each lock hole 15, and a lock portion 17 is formed at the other circumferential end of each lock hole 15. The release portion 16 is the part that allows the lock projection 51 to move in and out of the lock hole 15 via the insertion groove 19, which will be described later. When the lock projection 51 is positioned in the release portion 16 within the lock hole 15, the jack 2 and the plug 31 are in a state where the locking mechanism is released, i.e., they can be inserted and removed freely. The lock portion 17 is the part that holds the lock projection 51 within the lock hole 15. When the locking projection 51 is positioned within the locking hole 15 and the locking portion 17, the jack 2 and the plug 31 are locked in place, meaning they cannot be pulled out.

[0034] Furthermore, as shown in Figure 6(B), when the jack 2 is viewed from the front (one side in the axial direction), the position of one lock hole 15 in the circumferential direction of the female connector 8 is determined such that the locking portion 17 of the one lock hole 15 is located at the left-right center (width center) of the upper surface 9A of the gripping portion 9. That is, when the jack 2 is viewed from the front, one lock hole 15 extends from the leftmost to the topmost part of the circumferential wall of the female connector 8, and the locking portion 17 of the one lock hole 15 is located at the top of the female connector 8. As a result, the position of the locking portion 17 of one lock hole 15 coincides with the left-right center of the upper surface 9A of the gripping portion 9. Also, when the jack 2 is viewed from the front, the position of the other lock hole 15 in the circumferential direction of the female connector 8 is determined such that the locking portion 17 of the other lock hole 15 is located at the left-right center (width center) of the lower surface 9B of the gripping portion 9. In other words, the other lock hole 15 extends from the far right to the bottom of the peripheral wall of the female connector 8, and the locking portion 17 of the other lock hole 15 is located at the bottom of the female connector 8. As a result, the position of the locking portion 17 of the other lock hole 15 coincides with the position of the left-right center of the lower surface 9B of the gripping portion 9.

[0035] Furthermore, the width (length in the front-to-back direction) of each lock hole 15 is set to a value that is a predetermined amount larger than the diameter of the lock projection 51, so that the lock projection 51 can smoothly enter and exit the lock release portion 16 of the lock hole 15, so that the direction of movement of the lock projection 51 can be restricted so that the lock projection 51 moves circumferentially along the lock hole 15, and so that the lock projection 51 can move smoothly within the lock hole 15.

[0036] Furthermore, as shown in Figure 1 or Figure 7, a stopper portion 18 is formed on the front inner surface of the other circumferential end portion of each lock hole 15, projecting rearward from the inner surface. The stopper portion 18 has the function of holding the lock projection 51, which has moved to the other circumferential end (lock portion 17) within the lock hole 15, in place of the lock projection 51 within the lock hole 15.

[0037] Furthermore, as shown in Figure 6(A), two insertion grooves 19 are formed on the inner circumferential surface of the female connector 8 in the housing 7. These insertion grooves 19 function as passages that guide the locking projection 51 of the plug 31 into the locking hole 15 of the jack 2 when the jack 2 and the plug 31 are connected. Each insertion groove 19 opens onto the inner circumferential surface of the female connector 8, and the front end of each insertion groove 19 opens onto the front end surface of the female connector 8. The two insertion grooves 19 are located at two different locations on the inner circumferential surface of the female connector 8, 180 degrees apart. In the circumferential direction of the female connector 8, the positions of the two insertion grooves 19 correspond to the positions of the locking release portions 16 of the two locking holes 15. The rear end of one insertion groove 19 communicates with the locking release portion 16 of one locking hole 15, and the rear end of the other insertion groove 19 communicates with the locking release portion 16 of the other locking hole 15. The locking projection 51 can move in and out of the locking hole 15 by passing through the insertion groove 19.

[0038] Jack 2 can be assembled, for example, as follows: First, attach the ferrule 3 to the tip end of the optical fiber cable 91. Next, insert the optical fiber cable 91 into the housing 7 through the slit 14, while simultaneously inserting the ferrule 3 attached to the optical fiber cable 91 into the housing 7 from the front.

[0039] (plug) Figure 8 shows the plug 31 viewed from the upper right front. Figure 9 shows the plug 31 in a disassembled state. Furthermore, when describing the plug 31, the directions of up (Ud), down (Dd), front (Fd), back (Bd), left (Ld), and right (Rd) are indicated by the arrows drawn in Figures 8 and 9.

[0040] The plug 31 comprises a ferrule 33, a sleeve 37, a coil spring 39, and a housing 41. The housing 41 has a housing body 52 and a cover 53.

[0041] The ferrule 33 is attached to the leading end of the optical fiber cable 95. The optical fiber cable 95, like the optical fiber cable 91 described above, is a single-core optical fiber and has an optical fiber 96, a primary sheath 97, and a secondary sheath 98 (see Figure 2). The ferrule 33 also has a capillary 34 and a capillary support portion 35, similar to the ferrule 3 of the jack 2, and a flange portion 36 is formed on the front end of the capillary support portion 35. The method of attaching the optical fiber cable 95 to the ferrule 33 is the same as the method of attaching the optical fiber cable 91 to the ferrule 3 in the jack 2. The leading end surface (front end surface) of the capillary 34 of the ferrule 33 is, for example, mirror-polished into a dome shape, and the end face of the optical fiber 96 is exposed in its center.

[0042] The sleeve 37 is inserted so that the tip portion of the capillary 34 of the ferrule 33 of the plug 31 and the tip portion of the capillary 4 of the ferrule 3 of the jack 2 face each other, thereby aligning the axial position of the optical fiber 96 of the optical fiber cable 95 to which the ferrule 33 is attached with the axial position of the optical fiber 92 of the optical fiber cable 91 to which the ferrule 3 is attached. The sleeve 37 is formed in a cylindrical shape from a ceramic such as zirconia, or a metal such as phosphor bronze or nickel. The inner diameter of the sleeve 37 is set to be approximately equal to the outer diameter of the capillaries 4 and 34 so that radial displacement of the capillaries 4 and 34 inserted into the sleeve 37 can be suppressed with high precision. The sleeve 37 is a so-called split sleeve, and a slit 38 is formed in a part of its peripheral wall (see Figure 9). However, a sleeve 37 without a slit may also be used.

[0043] The housing 41 of the plug 31 is a component that houses the ferrule 33, sleeve 37, and coil spring 39, and is formed in a cylindrical shape from, for example, a resin material. As shown in Figure 8, a male connector 42 is formed on the front part of the housing 41, and a gripping part 43 is formed on the rear part of the housing 41. The male connector 42 is the part that is inserted into the female connector 8 of the housing 7 of the jack 2 when connecting the jack 2 and the plug 31, and is formed in a cylindrical shape. The gripping part 43 is the part that an operator or the like grips the housing 41 with their fingers when connecting the jack 2 and the plug 31. The gripping part 43 is formed in a cylindrical shape with a rectangular (for example, square) shape on the outer circumference of its cross-section and a circular shape on the inner circumference of its cross-section.

[0044] Furthermore, as shown in Figure 2, an insertion section 44, a sleeve housing section 45, a ferrule housing section 46, and a cable insertion section 47 are sequentially formed on the inner circumference of the housing 41, from the front end to the rear end. The insertion section 44 is the section into which the tip portion of the capillary 4 of the ferrule 3 of the jack 2 is inserted. The insertion section 44 opens forward on the front end surface of the housing 41. The sleeve housing section 45 is the section into which the sleeve 37 is housed. The ferrule housing section 46 is the section into which the ferrule 33 and the coil spring 39 are housed. The cable insertion section 47 is the section through which the optical fiber cable 95 attached to the ferrule 33 is inserted. The cable insertion section 47 opens rearward on the rear end surface of the housing 41.

[0045] Furthermore, a sleeve movement restricting portion 48 is formed on the inner circumference of the front end portion of the housing 41, which restricts the forward movement of the sleeve 37 housed in the sleeve housing portion 45. In the housing 41, the inner diameter of the insertion portion 44 is smaller than the inner diameter of the sleeve housing portion 45, and a step is formed at the boundary between the insertion portion 44 and the sleeve housing portion 45. This step is the sleeve movement restricting portion 48. The front end of the sleeve 37 comes into contact with the sleeve movement restricting portion 48, preventing the sleeve 37 from coming out of the sleeve housing portion 45.

[0046] Furthermore, a ferrule movement restricting portion 49 is formed on the front end side of the ferrule housing portion 46 to restrict the forward movement of the ferrule 33 housed within the ferrule housing portion 46. In the housing 41, the inner diameter of the sleeve housing portion 45 is smaller than the inner diameter of the ferrule housing portion 46, and the space between the sleeve housing portion 45 and the ferrule housing portion 46 gradually narrows towards the front. This gradually narrowing portion is the ferrule movement restricting portion 49. The front part of the flange portion 36 of the ferrule 33 comes into contact with the ferrule movement restricting portion 49, thereby restricting the forward movement of the ferrule 33 housed within the ferrule housing portion 46.

[0047] Furthermore, a spring contact surface 50 is formed on the rear end side of the ferrule housing portion 46, which contacts the rear end of the coil spring 39 housed within the ferrule housing portion 46. In the housing 41, the inner diameter of the cable insertion portion 47 is smaller than the inner diameter of the ferrule housing portion 46, and a stepped portion is formed at the boundary between the ferrule housing portion 46 and the cable insertion portion 47. The front surface of this stepped portion is the spring contact surface 50.

[0048] Furthermore, two locking protrusions 51 are provided on the outer circumferential surface of the male connector 42 approximately midway in the front-to-back direction. These locking protrusions 51, together with the locking hole 15 formed in the housing 7 of the jack 2, constitute a bayonet-type locking mechanism that prevents the jack 2 and plug 31, which are connected to each other, from coming loose. Each locking protrusion 51 protrudes radially from the outer circumferential surface of the male connector 42. Also, each locking protrusion 51 is positioned slightly forward of the midpoint in the front-to-back direction of the male connector 42. In addition, the two locking protrusions 51 are positioned at two locations on the outer circumferential surface of the male connector 42 that are 180 degrees apart.

[0049] Furthermore, as shown in Figure 9, the housing 41 can be divided into a housing body 52 that forms the front part of the housing 41 and a lid 53 that forms the rear part of the housing 41. That is, the housing 41 is formed by joining the lid 53 to the rear part of the housing body 52. ​​The division point where the housing 41 is divided into the housing body 52 and the lid 53 is set at the position where the ferrule housing portion 46 is formed in the housing 41. Also, a male coupling portion 54 is formed at the front end of the lid 53, and a locking projection 55 is formed on the male coupling portion 54. The rear end of the housing body 52 is open, and a locking hole 56 is formed at the rear end of the housing body 52. ​​The lid 53 is joined to the housing body 52 when the male coupling portion 54 is inserted into the rear end of the housing body 52 and the locking projection 55 is locked into the locking hole 56.

[0050] Furthermore, a slit 57 is formed in the right peripheral wall of the rear portion of the housing body 52. ​​The slit 57 has the function of allowing the rear end of the housing body 52 to be expanded in diameter. When the male coupling portion 54 of the lid 53 is pushed into the rear end of the housing body 52, the slit 57 opens, and the rear end of the housing body 52 expands in diameter. This allows the locking projection 55 to enter the locking hole 56.

[0051] Furthermore, a slit 58 is formed in the middle of the upper part of the peripheral wall of the cover 53 in the left-right direction. The slit 58 extends through the peripheral wall in the front-rear direction and has a width greater than the diameter of the optical fiber cable 95.

[0052] The plug 31 can be assembled as follows, for example. First, the optical fiber cable 95 is passed through the coil spring 39. Next, the ferrule 33 is attached to the tip end of the optical fiber cable 95. Next, with the housing 41 divided into the housing body 52 and the lid 53, the sleeve 37 is inserted into the housing body 52 from the rear and into the sleeve housing portion 45. Next, the ferrule 33 attached to the optical fiber cable 95 is inserted into the housing body 52 from the rear and the tip end of the capillary 34 of the ferrule 33 is inserted into the sleeve 37. Next, the coil spring 39 is inserted into the housing body 52 from the rear and positioned on the outer circumference of the rear portion of the capillary support portion 35 of the ferrule 33. Next, the optical fiber cable 95 is inserted into the cover 53 through the slit 58 of the cover 53, and the male connector 54 of the cover 53 is pushed (press-fitted) into the rear end of the housing body 52, thereby joining the housing body 52 and the cover 53.

[0053] (Connection between jack and plug) Figures 10(A), 10(B), and 10(C) show how to connect the jack 2 and the plug 31. When connecting the jack 2 and the plug 31, the worker grasps the gripping portion 9 of the housing 7 of the jack 2 with the thumb and index finger of the left hand, and the gripping portion 43 of the housing 41 of the plug 31 with the thumb and index finger of the right hand. Then, as shown in Figure 10(A), the worker aligns the locking projections 51 of the plug 31 with the insertion grooves 19 of the jack 2, faces the plug 31 and the jack 2, and inserts the male connector portion 42 of the plug 31 into the female connector portion 8 of the jack 2 in the direction of arrow A in Figure 10(A). As a result, each locking projection 51 enters the insertion groove 19, and the tip portion of the capillary 4 of the ferrule 3 of the jack 2 enters the insertion portion 44 of the plug 31. Furthermore, the tip of the capillary 4, which has entered the insertion section 44, enters the sleeve 37, which is housed in the sleeve housing section 45 of the plug 31, from one end of the sleeve 37. Then, the tip of the capillary 4 abuts against the tip of the capillary 34 of the ferrule 33 of the plug 31, which has already been inserted into the sleeve 37, from the other end of the sleeve 37.

[0054] Next, when the worker pushes the male connector 42 of the plug 31 into the female connector 8 of the jack 2, the rear surface 6A of the flange portion 6 of the capillary support portion 5 of the ferrule 3 of the jack 2 comes into contact with the front surface 12A of the stepped portion 12 of the housing 7 of the jack 2. Also, the capillary 34 of the ferrule 33 of the plug 31 is pushed by the capillary 4 of the ferrule 3 of the jack 2, causing the ferrule 33 of the plug 31 to retract within the ferrule housing portion 46 of the plug 31. As the ferrule 33 of the plug 31 retracts, the front end of the coil spring 39 housed within the ferrule housing portion 46 of the plug 31 comes into contact with the rear surface 36A of the flange portion 36 of the capillary support portion 35 of the ferrule 33, and the rear end of the coil spring 39 comes into contact with the spring contact surface 50 of the housing 41 of the plug 31. Furthermore, the coil spring 39 is pressed against the rear surface 36A of the flange portion 36 of the retracting ferrule 33's capillary support portion 35, causing it to contract. Due to the spring force of the contracted coil spring 39, the end face of the optical fiber 96 exposed at the tip surface of the capillary 34 of the ferrule 33 of the plug 31 and the end face of the optical fiber 92 exposed at the tip surface of the capillary 4 of the ferrule 3 of the jack 2 come into contact with each other, are pressed against each other, and become tightly attached. As a result, a physical contact is formed between the optical fiber 92 and the optical fiber 96.

[0055] Furthermore, when the operator pushes the male connector 42 of the plug 31 into the female connector 8 of the jack 2, each locking projection 51 moves within the insertion groove 19 toward the rear end of the jack 2 and enters the unlocking portion 16 of the lock hole 15, as shown in Figure 10(B). Then, before the coil spring 39 is compressed to its maximum extent, each locking projection 51 abuts against the rear inner surface of the unlocking portion 16 of the lock hole 15. When each locking projection 51 abuts against the rear inner surface of the unlocking portion 16 of the lock hole 15, the operator rotates the plug 31 approximately 60 degrees relative to the jack 2 in the direction of arrow B in Figure 10(B). As a result, each locking projection 51 moves within the lock hole 15 from the unlocking portion 16 toward the lock portion 17 in the direction of arrow B.

[0056] Then, as shown in Figure 10(C), each locking projection 51 moving within the locking hole 15 passes over the stopper portion 18 and reaches the locking portion 17. After each locking projection 51 reaches the locking portion 17, when the operator releases the force pushing the male connector portion 42 of the plug 31 into the female connector portion 8 of the jack 2, the spring force of the coil spring 39 causes each locking projection 51 to move towards the front end of the jack 2 within the locking portion 17. As a result, each locking projection 51 is locked to the stopper portion 18, preventing the jack 2 and plug 31 from coming loose and fixing them in place. In this state, the contracted state of the coil spring 39 is maintained, and as a result, the physical contact between the optical fiber 92 and the optical fiber 96 is maintained by the spring force of the coil spring 39.

[0057] When separating the jack 2 and the plug 31 and disconnecting the optical fiber 92 and the optical fiber 96, the operator rotates the plug 31 approximately 60 degrees relative to the jack 2 in the direction opposite to arrow B. This releases the locking protrusions 51 from each stopper portion 18, and each locking protrusion 51 moves into the unlocking portion 16 of the lock hole 15. After that, the operator pulls the plug 31 out of the jack 2. This causes each locking protrusion 51 to pass through the insertion groove 19 and exit the lock hole 15, while the male connector portion 42 of the plug 31 exits the female connector portion 8 of the jack 2.

[0058] As described above, in the jack 2 of the first embodiment of the present invention, a slit 14 for inserting the optical fiber cable 91 into the housing 7 is formed at the upper right corner of the peripheral wall of the housing 7. The slit 14 also passes through the upper right corner of the gripping portion 9 and opens at the boundary between the upper surface 9A and the right surface 9D of the gripping portion 9. As a result, when a worker grips the gripping portion 9 of the housing 7 of the jack 2 with, for example, their thumb and index finger, it is less likely that the worker's thumb (or index finger) will come into contact with the part of the outer surface of the peripheral wall of the gripping portion 9 of the housing 7 where the slit 14 opens.

[0059] In other words, when gripping the gripping portion 9 of the housing 7 of Jack 2 with the thumb and index finger, there are four possible combinations of places on the gripping portion 9 where the thumb and index finger make contact: (a) the left side 9C and the right side 9D, (b) the top side 9A and the bottom side 9B, (c) the upper left corner and the lower right corner, and (d) the lower left corner and the upper right corner. Of these combinations, the combinations of places where the operator can easily and stably grip the gripping portion 9 are the left side 9C and the right side 9D, and the top side 9A and the bottom side 9B. Therefore, when the operator grips the gripping portion 9 of the housing 7 of Jack 2 with the thumb and index finger, they usually grip the left side 9C and the right side 9D, or the top side 9A and the bottom side 9B. Figure 11(A) shows the state in which the operator grips the left side 9C and the right side 9D of the gripping portion 9 of the housing 7 of Jack 2 with the thumb and index finger of the left hand. Figure 11(B) shows the state in which the operator is gripping the upper surface 9A and lower surface 9B of the gripping portion 9 of the housing 7 of the jack 2 with the thumb and index finger of the left hand. In the jack 2 of this embodiment, the slit 14 passes through the upper right corner of the gripping portion 9, and the opening of the slit 14 is located at the boundary between the upper surface 9A and the right surface 9D of the gripping portion 9. Therefore, as shown in Figures 11(A) and 11(B), the operator's thumb (or index finger) does not come into contact with the opening of the slit 14 whether the operator is gripping the left surface 9C and the right surface 9D of the gripping portion 9, or whether the operator is gripping the upper surface 9A and the lower surface 9B of the gripping portion 9.

[0060] Thus, according to the Jack 2 of this embodiment, when an operator grips the gripping portion 9 of the housing 7 of the Jack 2 with their thumb and index finger, it is possible to make it less likely for the operator's thumb (or index finger) to come into contact with the opening of the slit 14. Therefore, it is possible to eliminate or reduce the feeling of discomfort that the operator may experience when gripping the gripping portion 9 of the housing 7 of the Jack 2. Furthermore, it is possible to eliminate or reduce the anxiety that when an operator grips the gripping portion 9 of the housing 7 of the Jack 2, their thumb (or index finger) may come into contact with the opening of the slit, causing debris to enter the housing through the slit. Consequently, according to the Jack 2 of this embodiment, it is possible to eliminate or reduce the impression that the Jack 2 is difficult to use.

[0061] Figure 12(A) shows a cross-section of the jack housing 61 according to the second embodiment of the present invention, Figure 12(B) shows a cross-section of the jack housing 71 according to the third embodiment of the present invention, and Figure 12(C) shows a cross-section of the jack housing 81 according to the fourth embodiment of the present invention. The positions (cutting positions) of the cross-sections of the housings 61, 71, and 81 in Figures 12(A) to (C) are the same as the positions of the cross-section of the housing 7 shown in Figure 6(B). In the jack housing 61 according to the second embodiment of the present invention, as shown in Figure 12(A), a slit 14 is formed at the upper left corner of the peripheral wall of the housing 61, and the slit 14 opens at the boundary between the left surface 9C and the upper surface 9A of the gripping portion 9. Accordingly, the jack housing 61 according to the second embodiment of the present invention differs from the housing 7 of the jack 2 according to the first embodiment of the present invention in the arrangement of each lock hole 15 (unlocking portion 16 and locking portion 17), as will be described later. The jack housing 61 of the second embodiment of the present invention is configured similarly to the housing 7 of the jack 2 of the first embodiment of the present invention, except for the arrangement of the slit 14 and each lock hole 15. Furthermore, in the jack housing 71 of the third embodiment of the present invention, as shown in Figure 12(B), the slit 14 is formed at the lower left corner of the peripheral wall of the housing 71, and the slit 14 opens at the boundary between the lower surface 9B and the left surface 9C of the gripping portion 9. The jack housing 71 of the third embodiment of the present invention is configured similarly to the housing 7 of the jack 2 of the first embodiment of the present invention, except for the arrangement of the slit 14. Furthermore, in the jack housing 81 of the fourth embodiment of the present invention, as shown in Figure 12(C), the slit 14 is formed at the lower right corner of the peripheral wall of the housing 81, and the slit 14 opens at the boundary between the right surface 9D and the lower surface 9B of the gripping portion 9. Furthermore, as described later, the jack housing 81 of the fourth embodiment of the present invention differs from the housing 7 of the jack 2 of the first embodiment of the present invention in the arrangement of each lock hole 15 (unlocking portion 16 and locking portion 17). The jack housing 81 of the fourth embodiment of the present invention is configured similarly to the housing 7 of the jack 2 of the first embodiment of the present invention, except for the arrangement of the slit 14 and each lock hole 15.According to the jacks of the second to fourth embodiments of the present invention, which each have housings 61, 71, and 81, similar to the jack 2 of the first embodiment of the present invention, when an operator grips the gripping portion 9 of the housings 61, 71, and 81 of the jack with their thumb and index finger, it is possible to make it less likely for the operator's thumb (or index finger) to come into contact with the opening of the slit 14. Therefore, it is possible to eliminate or reduce the impression that the jack is difficult for the operator to use.

[0062] Furthermore, in the housing 7 of the jack 2 of the first embodiment of the present invention, two locking holes 15, which constitute a bayonet-type locking mechanism that prevents the jack 2 and the plug 31 from coming loose together, are formed in the circumferential wall of the cylindrical female connector 8, along with the two locking protrusions 51 of the plug 31. When the jack 2 is viewed from the front, the position of one locking hole 15 is determined so that the locking portion 17 of one locking hole 15 is located in the left-right center (width center) of the upper surface 9A of the gripping portion 9, and the position of the other locking hole 15 is determined so that the locking portion 17 of the other locking hole 15 is located in the left-right center (width center) of the lower surface 9B of the gripping portion 9. As a result, when connecting the jack 2 and the plug 31, the operator can easily and reliably visually confirm that the locking protrusions 51 of the plug 31 are located within the locking portions 17 of the locking holes 15 of the jack 2, and that the jack 2 and the plug 31 are in a state where they are not coming loose. As a result, the workers come to perceive Jack 2 as easy to use.

[0063] For example, when connecting jack 2 and plug 31, the worker grasps the left side 9C and right side 9D of the gripping portion 9 of the housing 7 of jack 2 with the thumb and index finger of the left hand, as shown in Figure 11(A), and grasps the left side and right side of the gripping portion 43 of the housing 41 of plug 31 with the thumb and index finger of the right hand. Then, as shown in Figures 10(A) to (C), the worker inserts each locking projection 51 into the unlocking portion 16 of the lock hole 15 and rotates plug 31 in the direction of arrow B in Figure 10(B) to move each locking projection 51 from the unlocking portion 16 of the lock hole 15 to the locking portion 17. In the jack 2 of this embodiment, when the jack 2 is viewed from the front, the locking portion 17 of one of the locking holes 15 is located at the left-right center (width center) of the upper surface 9A of the gripping portion 9. Therefore, when one of the locking projections 51 moves to the locking portion 17 of one of the locking holes 15, the position of the locking projection 51 becomes the position corresponding to the left-right center of the upper surface 9A of the gripping portion 9, as shown in Figure 10(C). Generally, humans can intuitively and easily recognize the position of the width center of a rectangular plane with fairly high accuracy. The upper surface 9A of the gripping portion 9 is rectangular. Therefore, the operator can intuitively and easily recognize the position of the left-right center of the upper surface 9A with high accuracy. Consequently, the operator can intuitively and easily recognize with high accuracy that one of the locking projections 51, which moves from left to right in front of the upper surface 9A, has moved to a position corresponding to the left-right center of the upper surface 9A. In other words, the operator can intuitively, easily, and with high accuracy recognize that one of the locking protrusions 51 has moved to the locking portion 17 of the locking hole 15. By recognizing that one of the locking protrusions 51 has moved to the locking portion 17 of the locking hole 15, the operator can confirm that the jack 2 and the plug 31 are in a state where they are not coming loose. This is also true when the operator grips the upper surface 9A and lower surface 9B of the gripping portion 9 of the housing 7 of the jack 2 with the thumb and index finger of their left hand, and grips the upper surface and lower surface of the gripping portion 43 of the housing 41 of the plug 31 with the thumb and index finger of their right hand to connect the jack 2 and the plug 31.Thus, with the jack 2 of this embodiment, when connecting the jack 2 and the plug 31, the operator can easily and reliably recognize that the jack 2 and the plug 31 are in a state of being prevented from coming loose by visually confirming the positional relationship between the center of the width direction of the upper surface 9A, lower surface 9B, left surface 9C, or right surface 9D of the gripping portion 9 and the locking projection 51 (that the two are aligned).

[0064] In the jack housing 61 of the second embodiment of the present invention shown in Figure 12(A), and the jack housing 81 of the fourth embodiment of the present invention shown in Figure 12(C), when the housing 61 (or 81) is viewed from the front, one lock hole 15 extends from the lowest to the leftmost part of the peripheral wall of the female connector 8, and in one lock hole 15, the unlocking part 16 is located approximately at the lowest part of the female connector 8, and the locking part 17 is located at the leftmost part of the female connector 8. As a result, the position of the locking part 17 in one lock hole 15 coincides with the position of the left-right center of the left surface 9C of the gripping part 9. The other lock hole 15 extends from the highest to the rightmost part of the peripheral wall of the female connector 8, and in the other lock hole 15, the unlocking part 16 is located approximately at the highest part of the female connector 8, and the locking part 17 is located at the rightmost part of the female connector 8. As a result, the position of the locking portion 17 of the other locking hole 15 coincides with the position of the left-right center of the right surface 9D of the gripping portion 9. Furthermore, in the jack housing 71 of the third embodiment of the present invention shown in Figure 12(B), similar to the housing 7 of the jack 2 of the first embodiment of the present invention, when the housing 71 is viewed from the front, one locking hole 15 extends from the leftmost part to the topmost part of the peripheral wall of the female connector 8, and the locking portion 17 of one locking hole 15 is located at the top of the female connector 8. As a result, the position of the locking portion 17 of one locking hole 15 coincides with the position of the left-right center of the upper surface 9A of the gripping portion 9. Furthermore, the other locking hole 15 extends from the rightmost part to the bottommost part of the peripheral wall of the female connector 8, and the locking portion 17 of the other locking hole 15 is located at the bottom of the female connector 8. As a result, the position of the locking portion 17 of the other locking hole 15 coincides with the position of the left-right center of the lower surface 9B of the gripping portion 9. The jacks of the second to fourth embodiments of the present invention, each having housings 61, 71, and 81 respectively, also provide the same effect as the jack 2 of the first embodiment of the present invention, allowing for easy and reliable visual confirmation that the jack 2 and the plug 31 are in a locked state.

[0065] As described above, in the jack housings 7 and 71 of the first and third embodiments of the present invention, when the housing 7 (or 71) is viewed from the front, the position of the locking portion 17 of the locking hole 15 coincides with the left-right center (widthwise center) of the upper surface 9A or lower surface 9B of the gripping portion 9. Furthermore, in the jack housings 61 and 81 of the second and fourth embodiments of the present invention, when the housing 61 (or 81) is viewed from the front, the position of the locking portion 17 of the locking hole 15 coincides with the vertical center (widthwise center) of the left surface 9C or right surface 9D of the gripping portion 9. These configurations are made possible by forming the slit 14 at the corner of the peripheral wall of the housings 7, 61, 71, and 81. This point will be explained with reference to four comparative examples.

[0066] Figure 13(A) shows a cross-section of the jack housing 111 of the first comparative example, and Figure 13(B) shows a cross-section of the jack housing 121 of the second comparative example. Furthermore, Figure 13(C) shows a cross-section of the jack housing 131 of the third comparative example, and Figure 13(D) shows a cross-section of the jack housing 141 of the fourth comparative example. The housings 111, 121, 131, and 141 are configured similarly to the housing 7 of the jack 2 of the first embodiment of the present invention, except for the arrangement of the slits 164 and the arrangement of each lock hole 165. Also, the positions (cutting positions) of the cross-sections of the housings 111, 121, 131, and 141 in Figures 13(A) to (D) are the same as the positions of the cross-section of the housing 7 shown in Figure 6(B).

[0067] In the jack housing 111 of the first comparative example shown in Figure 13(A), the slit 164 is formed in the left-right center of the upper part of the peripheral wall of the housing 111. In the jack housing 121 of the second comparative example shown in Figure 13(B), the slit 164 is formed in the vertical center of the left part of the peripheral wall of the housing 121. In the jack housing 131 of the third comparative example shown in Figure 13(C), the slit 164 is formed in the left-right center of the lower part of the peripheral wall of the housing 131. In the jack housing 141 of the fourth comparative example shown in Figure 13(D), the slit 164 is formed in the vertical center of the right part of the peripheral wall of the housing 141.

[0068] Furthermore, in each of the housings 111, 121, 131, and 141, two locking holes 165 are formed in the peripheral wall of the female connector 158. These locking holes 165 are positioned at two locations 180 degrees apart on the peripheral wall of the female connector 158, and each locking hole 165 extends approximately 90 degrees in the circumferential direction along the peripheral wall of the female connector 158. In addition, a lock release portion 166 is formed at one circumferential end of each locking hole 165, and a locking portion 167 is formed at the other circumferential end of each locking hole 15. Moreover, the position of each locking hole 165 in the circumferential direction of the female connector 158 is set so that the locking holes 165 do not overlap with the slit 164. In the jack housing 111 of the first comparative example shown in Figure 13(A), in order to prevent each locking hole 165 from overlapping with the slit 164 formed in the left-right center of the upper part of the peripheral wall of the housing 111, one locking hole 165 is formed in the lower left to upper left portion of the peripheral wall of the female connector 158, and the other locking hole 165 is formed in the upper right to lower right portion of the peripheral wall of the female connector 158. As a result, the position of the locking portion 167 of one locking hole 165 and the position of the locking portion 167 of the other locking hole 165 do not coincide with the left-right center of the upper surface 159A of the gripping portion 159, the left-right center of the lower surface 159B, the vertical center of the left surface 159C, and the vertical center of the right surface 159D. This point is also the case in the jack housing 131 of the third comparative example shown in Figure 13(C). Furthermore, in the jack housing 121 of the second comparative example shown in Figure 13(B), in order to prevent each locking hole 165 from overlapping with the slit 164 formed in the left-right center of the peripheral wall of the housing 121, one locking hole 165 is formed in the portion from the upper left to the upper right of the peripheral wall of the female connector 158, and the other locking hole 165 is formed in the portion from the lower right to the lower left of the peripheral wall of the female connector 158. As a result, the position of the locking portion 167 of one locking hole 165, and the position of the locking portion 167 of the other locking hole 165, do not coincide with the left-right center of the upper surface 159A of the gripping portion 159, the left-right center of the lower surface 159B, the vertical center of the left surface 159C, and the vertical center of the right surface 159D of the gripping portion 159.This point is also true for the jack housing 141 of the fourth comparative example shown in Figure 13(D).

[0069] Thus, if the slit 164 is formed in the left-right center of the upper or lower part of the peripheral wall of the jack housing, or if the slit 164 is formed in the vertical center of the left or right part of the peripheral wall of the jack housing, then neither the position of the locking portion 167 of one locking hole 165 nor the position of the locking portion 167 of the other locking hole 165 will coincide with any of the positions of the left-right center of the upper surface 159A of the gripping portion 159, the left-right center of the lower surface 159B, the vertical center of the left surface 159C, or the vertical center of the right surface 159D. As can be seen from the above description, as in the first to fourth embodiments of the present invention, by forming the slit 14 at the corner of the peripheral wall of the jack housing, it becomes possible to align the position of the locking portion 17 of the lock hole 15 with the left-right center of the upper surface 9A or lower surface 9B of the gripping portion 9, or to align the position of the locking portion 17 of the lock hole 15 with the vertical center of the left surface 9C or right surface 9D of the gripping portion 9.

[0070] Furthermore, the present invention can also be applied to optical connectors in which a locking projection, rather than a locking hole, is formed on the peripheral wall of the connection portion that connects to the mating optical connector. In this case, a slit is formed at the corner of the peripheral wall of the housing, and two locking projections projecting radially outward from the outer peripheral surface of the connection portion are formed at two locations 180 degrees apart on the outer peripheral surface of the connection portion. The arrangement of the two locking projections in the circumferential direction of the connection portion is set such that, when the optical connector is viewed from the front, the position of one locking projection coincides with the left-right center (or the right-right center) of the upper surface of the gripping portion, and the position of the other locking projection coincides with the left-right center (or the right-right center) of the lower surface of the gripping portion.

[0071] Furthermore, the present invention may be modified as appropriate, provided that it does not contradict the gist or idea of ​​the invention as can be read from the claims and the specification as a whole, and optical connectors with such modifications are also included in the technical concept of the present invention. [Explanation of Symbols]

[0072] 1 Optical connector device 2 Jacks (Optical Connectors) 3 ferrules 7, 61, 71, 81 Housing 8. Female connector (connection part) 9 Gripping part 9A Top surface (first plane) 9B Bottom surface (second plane) 9C Left face (third plane) 9D Right side (4th plane) 11 Ferrule containment section 13 Cable insertion section 14 slits 15 lock holes 16. Unlocking section 17. Lock section 31 Plug (Mating optical connector) 51 Locking projection 91, 95 Fiber optic cable

Claims

1. An optical connector comprising a cylindrical housing for accommodating a ferrule attached to an optical fiber cable, The aforementioned housing is A connecting portion is formed on one axial side of the housing, opens on the one axial side, and into which a part of the mating optical connector is inserted and connected; A gripping portion is formed on the other axial side of the housing and is a portion that grips the housing, A ferrule housing portion formed inside the housing for accommodating the ferrule, A cable insertion portion is formed on the other axial end of the housing, opening to the other axial side, and through which the optical fiber cable to which the ferrule is attached is inserted, The housing is provided with a slit formed in the peripheral wall of the housing, extending through the peripheral wall of the housing in the axial direction of the housing, for inserting the optical fiber cable into the housing, The gripping portion is formed in the shape of a square tube, The outer circumferential surface of the gripping portion has a first plane, a second plane positioned on the outer circumferential surface of the gripping portion opposite to the portion on which the first plane is positioned, a third plane positioned between one widthwise edge of the first plane and one widthwise edge of the second plane, and a fourth plane positioned between the other widthwise edge of the first plane and the other widthwise edge of the second plane. The optical connector is characterized in that the slit is open at the boundary between the first plane and the fourth plane, the boundary between the third plane and the first plane, the boundary between the second plane and the third plane, or the boundary between the fourth plane and the second plane.

2. The optical connector according to claim 1, characterized in that a locking projection provided on the mating optical connector is inserted into a locking hole formed in the peripheral wall of the connecting portion, which together with the locking projection forms a bayonet-type locking mechanism that prevents the optical connector and the mating optical connector from coming apart.

3. The connecting portion is formed in a cylindrical shape, and two locking holes are formed in the peripheral wall of the connecting portion, and the two locking holes are arranged at two locations 180 degrees apart on the peripheral wall of the connecting portion, and each locking hole extends approximately 90 degrees in the circumferential direction along the peripheral wall of the connecting portion, and a locking portion is formed at one end of each locking hole in the circumferential direction, and a locking portion is formed at the other end of each locking hole in the circumferential direction, and when the locking projection is positioned in the locking portion within each locking hole, the optical connector and the mating optical connector are in a state of being prevented from coming loose, The optical connector according to claim 2, characterized in that, when the optical connector is viewed from one axial side, in the circumferential direction of the connection portion, the position of one of the two locking holes is determined such that the locking portion of the one locking hole is located in the widthwise center of the first plane of the gripping portion, and the position of the other locking hole is determined such that the locking portion of the other locking hole is located in the widthwise center of the second plane of the gripping portion, or, when the optical connector is viewed from one axial side, in the circumferential direction of the connection portion, the position of one of the two locking holes is determined such that the locking portion of the one locking hole is located in the widthwise center of the third plane of the gripping portion, and the position of the other locking hole is determined such that the locking portion of the other locking hole is located in the widthwise center of the fourth plane of the gripping portion.

Images