Abstract:
There is provided a waterproof connector. The waterproof connector comprises a connector member supporting a ferrule to be butted against a target ferrule disposed in a target connector, the connector member being adapted to be locked to an adapter member of the target connector by an action of a lock operation portion provided in the connector member; unlocking means being adapted to operate the lock operation portion to release the locked state; and a housing body allowing the unlocking means to be slidably moved. The waterproof connector is adapted to be released from the connection with the target connector in such a manner that the unlocking means is allowed to be moved away from the connector member, whereby the unlocking means is operable to operate the lock operation portion to release the locked state, and to move the connector member away from the adapter member to release the fitting.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    (i) Field of the Invention 
         [0002]    The present invention relates to a waterproof connector, and a waterproof device using the waterproof connector. 
         [0003]    (ii) Description of the Related Art 
         [0004]    One example of a conventional waterproof device is disclosed in JP 2007-537462A (hereinafter referred to as “Patent Document 1”).  FIGS. 21 and 22  are perspective views showing a waterproof device disclosed in the Patent Document 1. This waterproof device comprises a combination of a waterproof (sealed) connector  201  and a target connector  200 .  FIG. 21  is a front perspective view of the waterproof connector  201 , and  FIG. 22  is a perspective view showing the waterproof connector  201  together with the target connector  200  detachably connectable with the waterproof connector  201 , in a state before connection therebetween. 
         [0005]    As shown in  FIGS. 21 and 22 , the waterproof connector  201  primarily comprises an inner fiber connector assembly  206 , an inner connector housing  280  supporting the inner fiber connector assembly  206 , and a collar member  210  externally covering the inner connector housing  280  in a rotatable manner. In particular, the inner fiber connector assembly  206  includes a cantilever beam portion  122 , which has a latch provided on the side of an end thereof to be connected to the another connector  200 , and defined by a ramped surface  124  and a locking edge  126 , so as to establish a locked state with the target connector  200 . 
         [0006]    The target connector  200  has an opening  202  adapted to receive an end region of the inner fiber connector assembly  206  of the waterproof connector  201  during connection with the waterproof connector  201 . The opening  202  has a complementary alignment structure adapted to receive and latch into engagement with the locking edge  126  of the inner fiber connector assembly  206 . This structure makes it possible to allow the target connector  200  and the waterproof connector  201  to be mutually locked during connection therebetween. 
         [0007]    The locked state can be easily released by rotating the collar member  210  of the waterproof connector  201  with respect to the inner connector housing  280  in the arrowed direction “j” in  FIG. 21 . Specifically, along with the rotation of the collar member  210 , a cam member  260  is rotated, so that a cam face  266  of the cam member  260  is engaged with a top contact surface  119  of a lock mechanism (latch)  114  to deflect (bend) the lock mechanism  114  so as to release the locked state between the cantilever beam portion  122  of the waterproof connector  201  and the opening  202  of the target connector  200 , and the connection between the waterproof connector  201  and the target connector  200 . 
         [0008]    The conventional waterproof connector disclosed in the Patent Document 1 is configured such that the collar member  210  is rotated with respect to the inner connector housing  280  to allow the cam face  266  to deflect the lock mechanism  114  so as to release the locked state. In this configuration, it is difficult to figure out whether the locked state between the cantilever beam portion  122  of the waterproof connector  201  and the opening  202  of the target connector  200  is actually released. Moreover, it is necessary to release the locked state through a relatively complicated operation, specifically, a two-step operation consisting of “an operation of rotating the collar member  210 ” and “a pull-out operation”. 
         [0009]    Under the circumstances, the present invention intends to provide a waterproof connector capable of being connected to a target connector and released from the connection with the target connector, through a single-step operation, while facilitating checking of release of a locked state, and a waterproof device using the waterproof connector. 
       SUMMARY OF THE INVENTION 
       [0010]    It is a primary object of the present invention to provide a waterproof connector, which comprises: a connector member supporting a ferrule to be butted against a target ferrule disposed in a target connector, wherein the connector member is adapted to be detachably fitted into an adapter member provided in the target connector to support the target ferrule, in such a manner as to allow the ferrule to be butted against the target ferrule, and then locked to the adapter member to maintain the butting between the ferrule and the target ferrule, by an action of a lock operation portion provided in the connector member; unlocking means supporting the connector member while allowing the connector member to be freely moved within a given distance along a butting direction of the target ferrule and the target ferrule, wherein the unlocking means is adapted, when it is moved toward a side opposite to the target connector along the butting direction, to operate the lock operation portion to release the locked state between the connector member and the adapter member; a generally cylindrical-shaped joining member protruding toward the target connector along the butting direction, wherein the joining member is adapted to be fixed to a cylindrical portion of the target connector protruding toward the connector member while surrounding a periphery of the adapter member along the butting direction, and, when it is fixed to the cylindrical portion, to form an overlapping region with the cylindrical portion along the butting direction; and a housing body supporting the joining member, and supporting the unlocking means while allowing the unlocking means to be slidably moved within a given distance along the butting direction, wherein: the waterproof connector is adapted to be connected to the target connector in such a manner that the housing body is moved toward the target connector along the butting direction to allow the unlocking means supported by the housing body to be moved closer to the connector member supported by the unlocking means and then allow the connecter member supported by the unlocking means to be moved closer to the adapter member and fitted into the adapter member, while allowing the joining member supported by the housing body to be moved closer to the cylindrical portion, and then the joining member is fixed to the cylindrical portion while slidingly moving the housing body along the butting direction; and the waterproof connector is adapted to be released from the connection with the target connector in such a manner that the fixing between the joining member and the cylindrical portion is released while slidingly moving the housing body along the butting direction, and then the housing body is moved toward the side opposite to the target connector along the butting direction to allow the joining member supported by the housing body to be moved away from the cylindrical portion, and allow the unlocking means supported by the housing body to be moved away from the connector member supported by the unlocking means, whereby the unlocking means is operable to operate the lock operation portion provided in the connector member, to release the locked state between the adapter member and the connector member, and to move the connector member supported thereby away from the adapter member to release the fitting between the connector member and the adapter member. 
         [0011]    According to one embodiment of the present invention, the waterproof connector comprises an elastic member disposed between the unlocking means and the housing body, wherein the unlocking means is constantly biased by the elastic member, toward the target connector along the butting direction. 
         [0012]    According to another embodiment of the present invention, the waterproof connector comprises a coupling member disposed in a space defined by two concave portions formed in respective ones of an outer wall of the unlocking means and an inner wall of the housing body and communicated in a direction intersecting with the butting direction, wherein the housing body supports the unlocking means through the coupling member, to allow the unlocking means to be slidably moved within a given distance along the butting direction. 
         [0013]    According to another embodiment of the present invention, in the above waterproof connector, the unlocking means supported by the housing body is adapted to be moved closer to the connector member through the coupling member. 
         [0014]    According to another embodiment of the present invention, in the above waterproof connector, the unlocking means supported by the housing body is adapted to be moved away from to the connector member through the coupling member. 
         [0015]    According to another embodiment of the present invention, in the waterproof connector, the connector member is supported by the unlocking member in a freely movable manner along the butting direction, in such a manner as to penetrate through a through-hole formed in the unlocking means, wherein a movement of the connector member toward the target connector is restricted through a collision between a protrusion provided on an outer surface of the connector member and a front wall of the unlocking means defining a front opening of the through-hole, in the butting direction, and a movement of the connector member toward the side opposite to the target connector is restricted through a collision between a collision member provided at a rear end of the connector member and a rear wall of the unlocking means defining a rear opening of the through-hole, in the butting direction. 
         [0016]    According to another embodiment of the present invention, in the above waterproof connector, the connector member supported by the unlocking means is adapted to be moved closer to the adapter member by means of the collision between the protrusion provided on the outer surface of the connector member and the front wall of the unlocking means defining the front opening of the through-hole, in the butting direction. 
         [0017]    According to another embodiment of the present invention, in the above waterproof connector, the connector member supported by the unlocking means is adapted to be moved away from the adapter member by means of the collision between the collision member provided at the rear end of the connector member and the rear wall of the unlocking means defining the rear opening of the through-hole, in the butting direction. 
         [0018]    According to another embodiment of the present invention, in the waterproof connector, the lock operation portion has a tab formed to protrude in the butting direction and have a distal end region protruding toward the lock operation portion to wrap around a free end of the lock operation portion, wherein the unlocking means is adapted to operate the lock operation portion using the tab to release the locked state between the adapter member and the connecter member. 
         [0019]    According to another embodiment of the present invention, in the waterproof connector, the joining member is freely fitted onto the housing body. 
         [0020]    According to another embodiment of the present invention, in the waterproof connector, the housing body has a tubular portion protruding toward the target connector along the butting direction to form an overlapping region with an inner periphery of the cylindrical portion along the butting direction when the joining member is fixed to the cylindrical portion, wherein, when the waterproof connector is connected to the target connector, the joining member is disposed to cover an outer periphery of the cylindrical portion of the target connector, and the cylindrical portion of the target connector is inserted in a gap defined between the joining member and the tubular portion of waterproof connector. 
         [0021]    According to another embodiment of the present invention, the waterproof connector comprises a holding member disposed within the housing body and fixed to a rigid cord member extending inside the housing body together with an optical fiber connected to the ferrule, wherein the holding member is adapted, when the rigid cord member is pulled toward the side opposite to the target connector along the butting direction, to be brought into contact with an inner wall of the housing body to reduce a force to be applied to the optical fiber. 
         [0022]    According to another embodiment of the present invention, in the waterproof connector, the connector member has a structure of an LC connector. 
         [0023]    It is another object of the present invention to provide a waterproof device, which comprises the above waterproof connector, and a target connector connectable with the waterproof connector. 
         [0024]    It is a further object of the present invention to provide a waterproof connector which comprises: a connector member supporting a ferrule to be butted against a target ferrule disposed in a target connector, wherein the connector member is adapted to be locked to an adapter member of the target connector to maintain the butting between the ferrule and the target ferrule, by an action of a lock operation portion provided in the connector member; unlocking means supporting the connector member while allowing the connector member to be freely moved along a butting direction of the ferrule and the target ferrule, wherein the unlocking means is adapted, when it is moved toward a side opposite to the target connector along the butting direction, to operate the lock operation portion to release the locked state between the connector member and the adapter member; and a housing body supporting the unlocking means while allowing the unlocking means to be slidably moved along the butting direction, wherein: the waterproof connector is adapted to be connected to the target connector in such a manner that the housing body is moved toward the target connector along the butting direction to allow the unlocking means supported by the housing body to be moved closer to the connector member and then allow the connecter member supported by the unlocking means to be moved closer to the adapter member and fitted into the adapter member; and the waterproof connector is adapted to be released from the connection with the target connector in such a manner that the housing body is moved toward the side opposite to the target connector along the butting direction to allow the unlocking means supported by the housing body to be moved away from the connector member supported by the unlocking means, whereby the unlocking means is operable to operate the lock operation portion provided in the connector member, to release the locked state between the adapter member and the connector member, and to move the connector member supported thereby away from the adapter member to release the fitting between the connector member and the adapter member. 
         [0025]    As above, the present invention can provide a waterproof connector capable of being connected to a target connector and released from the connection with the target connector, through a single-step operation, and a waterproof device using the waterproof connector. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0026]      FIG. 1  is an external perspective view showing a waterproof device according to one embodiment of the present invention. 
           [0027]      FIG. 2  is an exploded perspective view showing a waterproof connector (plug connector) in the waterproof device according to the embodiment. 
           [0028]      FIG. 3  is a horizontal sectional view showing the waterproof connector and a target connector (receptacle connector) in the waterproof device according to the embodiment, taken along an axis thereof. 
           [0029]      FIG. 4  is a vertical sectional view taken along the line B-B in  FIG. 3 . 
           [0030]      FIGS. 5(   a ) and  5 ( b ) are diagrams showing a sequence of operation for connecting the plug connector and the receptacle connector. 
           [0031]      FIG. 6  is a fragmentary enlarged view of a region B in  FIG. 5(   b ). 
           [0032]      FIGS. 7(   a ) and  7 ( b ) are diagrams showing the sequence of operation for connecting the plug connector and the receptacle connector. 
           [0033]      FIG. 8  is a fragmentary enlarged view of a region C in  FIG. 7(   b ). 
           [0034]      FIGS. 9(   a ) and  9 ( b ) are diagrams showing the sequence of operation for connecting the plug connector and the receptacle connector. 
           [0035]      FIG. 10  is a fragmentary enlarged view of a region E in  FIG. 9(   b ). 
           [0036]      FIGS. 11(   a ) and  11 ( b ) are diagrams showing the sequence of operation for connecting the plug connector and the receptacle connector. 
           [0037]      FIG. 12  is a fragmentary enlarged view of a region G in  FIG. 11(   b ). 
           [0038]      FIGS. 13(   a ) and  13 ( b ) are diagrams showing a sequence of operation for pulling the plug connector away from the receptacle connector. 
           [0039]      FIG. 14  is a fragmentary enlarged view of a region H in  FIG. 13(   b ). 
           [0040]      FIGS. 15(   a ) and  15 ( b ) are diagrams showing the sequence of operation for pulling the plug connector away from the receptacle connector. 
           [0041]      FIG. 16  is a fragmentary enlarged view of a region I in  FIG. 15(   b ). 
           [0042]      FIGS. 17(   a ) and  17 ( b ) are diagrams showing the sequence of operation for pulling the plug connector away from the receptacle connector. 
           [0043]      FIG. 18  is a fragmentary enlarged view of a region J in  FIG. 17(   b ). 
           [0044]      FIGS. 19(   a ) and  19 ( b ) are diagrams showing the sequence of operation for pulling the plug connector away from the receptacle connector. 
           [0045]      FIG. 20  is a fragmentary enlarged view of a region K in  FIG. 19(   b ). 
           [0046]      FIG. 21  is a front perspective view showing a conventional waterproof connector. 
           [0047]      FIG. 22  is a perspective view showing the waterproof connector illustrated in  FIG. 21 , together with a target connector, in a state before connection therebetween. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0048]    Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 
         [0049]      FIG. 1  is an external perspective view showing a waterproof device  1  according to one embodiment of the present invention. The waterproof device  1  comprises a combination of a plug connector (waterproof connector)  10  and a receptacle connector (target connector)  80 , which are adapted to be connected together.  FIG. 2  is an exploded perspective view showing only the plug connector  10 .  FIG. 3  a horizontal sectional view showing the plug connector  10  and the receptacle connector  80 , taken along an axis of the waterproof device, and  FIG. 4  is a vertical sectional view taken along the line B-B in  FIG. 3 . For convenience of illustration,  FIG. 1  shows a state before connection between the plug connector  10  and the receptacle connector  80 , and  FIGS. 3 and 4  show a state after connection therebetween. 
         [0050]    The receptacle connector  80  may be used, for example, under a condition that it is fixed to a wall (not shown) by a screw (not shown) provided to penetrate through a screw hole  85  formed therein. In this case, in order to prevent formation of a gap between the wall and the receptacle connector  80 , an O-ring  83  may be installed in an annular-shaped recess  92  formed in a R shell  82  thereof. The O-ring  83  makes it possible to close a gap between the wall and the receptacle connector  80  so as to more reliably keep out water. 
         [0051]    The plug connector  10  and the receptacle connector  80  are fixed to each other by a bayonet connection, so as to maintain a connected state therebetween. In order to establish the fixing based on the bayonet connection, a pair of fixing grooves  90  are formed in an outer surface of a cylindrical portion  86  of the receptacle connector  80  to be located in opposed relation to each other. Correspondingly, a pair of protrusions  36  are formed on an inner peripheral surface of an end of a joining member  18  of the plug connector  10  to be located in opposed relation to each other. The cylindrical portion  86  is formed to protrude toward a connector member  12  while surrounding a periphery of an LC adapter (adapter member)  81  of the receptacle connector  80 . In an operation of fixing the plug connector  10  to the receptacle connector  80  by the bayonet connection, the protrusions  36  of the joining member  18  are pushed into and along the corresponding ones of the fixing grooves  90  of the cylindrical portion  86  in the arrowed direction “c 1 ” in  FIG. 1 , and then the joining member  18  is rotated in the direction “d” in  FIG. 1  along an outer surface of the cylindrical portion  86  to allow the protrusions  36  of the joining member  18  to be put into respective recesses  98  of the cylindrical portion  86 . 
         [0052]    The LC adapter  81  is provided with four fitting spaces  84 . Each of the fitting spaces  84  is adapted to allow the connector member  12  of the plug connector  10  and a connector member of the receptacle connector  80  formed in the same configuration as that of the connector member  12  to be fittingly inserted thereinto from opposite sides in such a manner that they are butted against each other. Specifically, a target ferrule (not shown) supported by a connector member (not shown) of the receptacle connector  80  is disposed in a region of the fitting space  84  on the side of the receptacle connector  80 , and then the connector member  12  of the plug connector  10  is fitted into a region of the fitting space  84  on the side of the plug connector  10 , so that a ferrule  23  supported by the connector member  12  of the plug connector  10  can be butted against the target ferrule through a connection sleeve  91  provided in the LC adapter  81 , to establish an optical connection. An optical fiber  22  is fixed to an end face of the ferrule  23 , while exposing a fiber core thereof. The optical fiber  22  is, for example, led out from a jacket  29  of a cable  28  covering it together with a tension member (rigid cord member)  21 , to extend inside the connector member  12 . 
         [0053]    The plug connector  10  primarily comprises a cord tube (housing body)  14  formed in a cylindrical-shaped body, a plurality of components arranged along the arrowed direction “f” in  FIG. 2  and attached to the cord tube  14 , such as a rubber hood  11 , the connector member  12 , an LC knob  62 , a scroll wave ring  24  and a holding member  13 , and a plurality of components arranged along the arrowed direction “g” in  FIG. 2  and attached to the cord tube  14 , such as the joining member  18 , a fastener  17 , a cord clamp  16  and a gasket  15 . Each of the rubber hood  11 , the gasket  15 , the cord clamp  16  and the fastener  17  is formed in a generally cylindrical shape in conformity to the cord tube  14 . 
         [0054]    In this embodiment, the connector member  12  is shown as a type including two connector members  12   a ,  12   b  each having the same configuration, by way of example. Alternatively, the number of connector members may be only one, or may be three or more. Each of the connector members  12   a ,  12   b  has the same configuration as that of a conventional commercially-available LC connector. This means that the present invention can be widely used in the conventional LC connector. The connector segment  12  ( 12   a ,  12   b ) has a cantilever beam portion (lock operation portion)  61  ( 61   a ,  61   b ) formed to extend rearwardly and obliquely upwardly. The cantilever beam portion  61  ( 61   a ,  61   b ) has a lock protrusion  73  ( 73   a ,  73   b ) formed on a lateral surface thereof. The lock protrusion  73  ( 73   a ,  73   b ) is adapted, when the connector member is fitted into the LC adapter  81 , to be latched by a complementary shaped portion of the LC adapter  81  (a corresponding one of two concave-shaped lock portions provided in the LC adapter  81  (indicated by the reference numeral  87  in FIG.  11 )), to allow the connector member  12  to be locked. This makes it possible to maintain butting between the ferrule  23  and the target ferrule. 
         [0055]    As is well known, the lock by the cantilever beam portion  61  is automatically achieved by allowing the connector member  12  to be moved closer to the LC adapter  81 , without a particular operation. More specifically, along with an operation of inserting the cantilever beam portion  61  ( 61   a ,  61   b ) into the fitting or receiving space  84  ( 84   a ,  84   b ) (see  FIG. 3 ) of the LC adapter  81 , The cantilever beam portion  61  ( 61   a ,  61   b ) is automatically displaced downwardly through a collision with the LC adapter  81 . Then, after the lock protrusion  73  ( 73   a ,  73   b ) is received in the corresponding lock portion  87 , the cantilever beam portion  61  ( 61   a ,  61   b ) is automatically returned upwardly to automatically lock the connector member  12 . Differently, in an operation of pulling the connector member  12  away from the LC adapter  81 , it is necessary to pulling the connector member  12  out of the LC adapter  81 , while displacing the cantilever beam portion  61  ( 61   a ,  61   b ) downwardly by an external operation to release the locked state between the LC adapter  12  and the lock protrusion  73  ( 73   a ,  73   b ) of the connector member  12 . Typically, the downward displacement of the cantilever beam portion  61  ( 61   a ,  61   b ) is performed through a manual operation by a user. In this embodiment, the LC knob (unlocking means)  62  is provided in such a manner as to be automatically operated in conjunction with movement of other members to perform the downward displacement, as described in detail later. Thus, the plug connector  10  in this embodiment can be connected to the receptacle connector  80  and released from the connection with the receptacle connector  80 , through a single-step operation. 
         [0056]    The connector member  12  ( 12   a ,  12   b ) is coupled to the LC knob  62  in such a manner as to be freely moved within a given distance along a butting direction of the ferrule and the target ferrule (a fitting direction of the connector member  12  and the LC adapter  81 ). More specifically, in order to couple the connector member  12  to the LC knob  62  in a freely movable manner, a certain level of play is provided between the gasket  15  and the connector member  12 . The LC knob  62  generally comprises a flange  65  provided on a front side thereof, and a tubular portion  75  provided on a rear side thereof. A rear surface of the flange  65  is in contact with the scroll wave ring  24  as an elastic member disposed between the LC knob  62  and the cord tube  14 , so that the LC knob  62  is constantly biased frontwardly, i.e., in a direction causing the fitting between the connector member  12  and the LC adapter  81 . 
         [0057]    The flange  65  of the LC knob  62  is formed with a through-hole  69  communicated with an inside of the tubular portion  75 . A rear end region  68  of the connector member  12  is inserted into and supported by the through-hole  69  and the tubular portion  75 . The connector member  12  can be freely moved with respect to the LC knob  62  along the fitting direction of the connector member  12  and the LC adapter  81 , while being inserted into and supported by the through-hole  69  and the tubular portion  75 . However, a frontward movement (i.e., a movement toward the receptacle connector  80 ) of the connector member  12  is restricted through a collision between a plate-shaped collision spacer  64  provided at a rear end of the connector member  12  and a rear wall  74  of the LC knob  62  defining a rear opening of the through-hole  69 . Further, a rearward movement (i.e., a movement toward a side opposite to the receptacle connector  80 ) of the connector member  12  is restricted through a collision between a protrusion  66  provided on a lower region of an outer surface of the connector member  12  and a front wall  72  of the LC knob  62  defining a front opening of the through-hole  69 . Thus, the connector member  12  is never pulled out of the LC knob  62 . The collision spacer  64  can be attached to the connector member  12  in the arrowed direction “e”, as shown in  FIG. 2 . 
         [0058]    The LC knob  62  has a tab  67  provided on a front side of an upper portion of the flange  65 . The tab  67  is formed to protrude frontwardly and have a front end region protruding downwardly, i.e., toward the cantilever beam portion  61 , so that the tab  67  generally has a shape capable of wrapping around a free end of the cantilever beam portion  61 . Thus, when the LC knob  62  is moved rearwardly with respect to the connector member  12 , the cantilever beam portion  61  ( 61   a ,  61   b ) is pushed downwardly through a contact between the tab  67  and the free end  76  of the cantilever beam portion  61 , so that the locked state between the connector member  12  and the LC adapter  81  is released. This means that the locked state between the connector member  12  and the LC adapter  81  can be released by moving the LC knob  62  rearwardly with respect to the connector member  12 . 
         [0059]    The cord tube  14  can be classified into a small-diameter portion  50 , an intermediate-diameter portion  51 , and a large-diameter portion  52 , for convenience of explanation. The small-diameter portion  50  has the gasket  15 , the cord clamp  16  and the fastener  17  which are attached thereto while allowing the cable  28  to penetrate therethrough. This makes it possible to achieve a more reliable waterproof structure. A rear end of the small-diameter portion  50  is formed to have an increased inner diameter. The gasket  15  is inserted into the increased-diameter portion, and the cord clamp  16  is attached to compress the gasket  15  having the cable  28  penetrating therethrough. Then, the fastener  17  is attached to compress an elastic portion  58  provided at a rear end of the cord clamp  16 , to reduce a diameter of the elastic portion  58 . Specifically, a rear end of the fastener  17  is formed as a tapered portion  57  having an inner diameter which gradually decreases toward a rear edge thereof, so that the elastic portion  58  is compressed by the tapered portion  57 , to allow the cable  28  to be fixed. In order to facilitate positioning of the cord clamp  16  relative to the small-diameter portion  50 , a positioning cutout (not shown) may be formed in an inner wall of the small radius portion  50 , and correspondingly a positioning protrusion  56  may be formed on the cord clamp  16 . In a state after all the above components are attached to the small-diameter portion  50 , an outer surface of the small-diameter portion  50 , and an outer surface of the elastic portion  58  provided at the rear end of the cord clamp  16  to protrude from the small-diameter portion  50 , are fully covered by the fastener  17 . 
         [0060]    The intermediate-diameter portion  51  is formed and arranged to support the tubular portion  75  of the LC knob  62 . The tubular portion  75  has an outer diameter approximately equal to an inner diameter of the intermediate-diameter portion  51 . Thus, the cord tube  14  supports the LC knob  62  while allowing the LC knob  62  to be slidingly moved within a given distance along the butting direction of the ferrule  23  and the target ferrule (along the arrowed direction “c” in  FIG. 2 ). Further, the plate-shaped holding member  13  is received in the intermediate-diameter portion  51 . The holding member  13  has an outer diameter less than an inner diameter of the intermediate-diameter portion  51 , so that the holding member  13  is fully inserted into the intermediate-diameter portion  51 . The holding member  13  is provided with a slit  63  which allows an end of the tension member  21  to be inserted thereinto. The tension member  21  can be inserted into the slit  63 , and fixed to the holding member  13  using a screw (not shown) provided to penetrate through a screw hole  26  formed therein. The tension member  21  is fixed to the holding member  13  in the above manner. Thus, for example, even if the tension member  21  is pulled along the butting direction and toward the side opposite to the receptacle connector  80 , a rear surface  45  of the holding member  13  is brought into contact with an inner wall  47  of a rear end of the cord tube  14 , so that a pulling force can be transmitted to the cord tube  14  to reduce a force to be applied to the optical fiber  22 . 
         [0061]    A rear plate  35  of the joining member  18  is positioned around a boundary between the intermediate-diameter portion  51  and the large-diameter portion  52 , and then a C-shaped retainer member (spring washer)  19  is attached to an outer peripheral surface of a front end of the intermediate-diameter portion  51 . The retainer member  19  is adapted to collide with the rear plate  35  of the joining member  18  supported by the intermediate-diameter portion  51 , to prevent pull-out of the joining member  18  from the intermediate-diameter portion  51 . The retaining member  19  is elastically fitted into a circular C-shaped concave portion  32  formed in the intermediate-diameter portion  51 . 
         [0062]    A C-shaped spring washer (coupling member)  20  is attached to an inner peripheral surface of the front end of the intermediate-diameter portion  51  at a position adjacent to an inner surface the retainer member  19 . The spring washer  20  is elastically attached as with the retainer member  19 . Specifically, the spring washer  20  is disposed to extend over a space  60  defined by an annular-shaped outer concave portion  30  formed in an outer wall  38  of the tubular portion  75  of the LC knob  62  and an annular-shaped inner concave portion  33  formed in an inner wall  39  of the cord tube  14 , to couple the LC knob  62  and the cord tube  14  together. The annular-shaped outer concave portion  30  and the annular-shaped inner concave portion  33  define two recesses communicated in a direction intersecting with the butting direction (in the arrowed direction “h” in  FIG. 4 ). In particular, the annular-shaped outer concave portion  30  defines a recess having a length greater than that of the spring washer  20  in the butting direction (the arrowed direction “c”). The recess of the annular-shaped outer concave portion  30  having such a length allows the LC knob  62  to be slidingly moved within a given distance with respect to the cord tube  14 . A part of a rear end of the intermediate-diameter portion  51  is formed as a pair of flat portions  53  located in opposed relation to each other to perform a tightening operation using a tool such as a spanner. The fastener  17  is also formed with a pair of flat portions. 
         [0063]    The large-diameter portion  52  has a tubular portion  25  formed to protrude toward the cylindrical portion  86  of the receptacle connector  80  along the butting direction. The connector member  12 , and the flange  65  of the LC knob  62  coupled to the connector member  12 , can be slidingly moved inside the tubular portion  25  within a given distance along the butting direction. In an operation of fixing the plug connector  10  to the receptacle connector  80 , the tubular portion  25  can be brought into contact with an inner peripheral surface  97  of the cylindrical portion  86  to form an overlapping region  88  with the cylindrical portion  86  along the butting direction. The formation of the overlapping region  88  makes it possible to more effectively keep out water. Further, the generally cylindrical-shaped joining member  18  after penetrating the intermediate-diameter portion  51  is freely fitted onto the large-diameter portion  52 . The joining member  18  is a generally cylindrical-shaped member which protrudes toward the receptacle connector  80  along the butting direction of the ferrule  23  and the target ferrule and covers an outer periphery of the large-diameter portion  52 . In the operation of fixing the plug connector  10  to the receptacle connector  80 , the joining member  18  is connected to the cylindrical portion  86  of the receptacle connector  80  by the bayonet connection, in the aforementioned manner. In the operation of fixing the plug connector  10  to the receptacle connector  80 , the cylindrical portion  86  of the receptacle connector  80  is disposed while being inserted into a gap  99  defined between the joining member  18  and the tubular portion  25  of the plug connector  10 . The joining member  18  can cover an outer peripheral surface  96  of the cylindrical portion  86  and form an overlapping region  87  with the cylindrical portion  86  along the butting direction, as with the tubular portion  25 . This makes it possible to reliably keep out water. The rubber hood  11  provided in the gap  99  defined between the joining member and the large-diameter portion  52  can also enhance the waterproof effect. The rubber hood  11  is positioned in such a manner that it is received in an annular-shaped positioning recess  54  formed in the tubular portion  25 , and a rear surface thereof is butted against a flange  27  of the tubular portion  25  constituting a part of the large-diameter portion  52 . In an operation of connecting the plug connector  10  to the receptacle connector  80 , a raised portion  41  formed at a front end of the rubber hood  11  is brought into close contact with a thin-walled region  89  of the cylindrical portion  86 , so that the gap can be more reliably closed. 
         [0064]    With reference to  FIGS. 5(   a ) to  20 , a function of the waterproof device  1  will be described.  FIGS. 5(   a ) to  12  show a sequence of operation for connecting the plug connector  10  to the receptacle connector  80 , i.e., a sequence of operation for fitting the connector member  12  into the LC adapter  81 .  FIGS. 13(   a ) to  20  show a sequence of operation for releasing the connection between the plug connector  10  and the receptacle connector  80 , i.e., a sequence of operation for pulling the connector member  12  away from the LC adapter  81 . 
         [0065]    In  FIGS. 5(   a ) and  5 ( b ) to  FIGS. 19(   a ) to  19 ( b ), the figure suffixed with (a) indicates a section line in the vertical sectional view of the figure suffixed with (b), and shows a state during the operation of connecting the plug connector  10  to the receptacle connector  80  (fitting the connector member  12  into the LC adapter  81 , for convenience of illustration. In the vertical sectional views taken along the section line located at the same position in the figure suffixed with (a), each component is defined by a common reference numeral or code. For example, a position of the line A-A indicated in  FIG. 5(   a ) is the same as that of the line A-A indicated in  FIG. 7(   a ), but it is different from that of the line D-D indicated in  FIG. 9(   a ).  FIGS. 6 ,  8 ,  10 ,  12 ,  14 ,  16 ,  18  and  20  are fragmentary enlarged views of respective regions shown in  FIGS. 5(   b ),  7 ( b ),  9 ( b ),  11 ( b ),  13 ( b )  15 ( b ),  17 ( b ) and  19 ( b ). More specifically,  FIG. 6  is a fragmentary enlarged view of a region B in  FIG. 5(   b ), and  FIG. 8  is a fragmentary enlarged view of a region C in  FIG. 7(   b ).  FIG. 10  is a fragmentary enlarged view of a region E in  FIG. 9(   b ), and  FIG. 12  is a fragmentary enlarged view of a region G in  FIG. 11(   b ).  FIG. 14  is a fragmentary enlarged view of a region H in  FIG. 13(   b ), and  FIG. 16  is a fragmentary enlarged view of a region I in  FIG. 15(   b ), and  FIG. 18  is a fragmentary enlarged view of a region J in  FIG. 17(   b ).  FIG. 20  is a fragmentary enlarged view of a region K in  FIG. 19(   b ) 
         [0066]    With reference to  FIGS. 5(   a ) to  12 , a movement during operation of connecting the plug connector  10  to the receptacle connector  80  will be described below. 
         [0067]    1) As shown in  FIGS. 5(   a ),  5 ( b ) and  6 , the cord tube  14  is moved toward the receptacle connector  80  (the arrowed direction “c 1 ”) along the fitting direction of the connector member  12  and the LC adapter  81 , to allow the joining member  18  supported by the cord tube  14  to be moved closer to the cylindrical portion  86 , and allow a rear surface  77  of an inner wall of the concave portion  33  of the cord tube  14  to be brought into contact with a rear surface of the spring washer  20 , so that the spring washer  20  is integrally moved together with the cord tube  14 . 
         [0068]    2) As shown in  FIGS. 7(   a ),  7 ( b ) and  8 , the cord tube  14  is further moved toward the receptacle connector  80 , to allow a front surface  49  of the spring washer  20  to be brought into contact with a front surface  70  of an inner wall of the concave portion  30  of the LC knob  62 , so that the LC knob  62  supported by the cord tube  14  is moved toward the connector member  12  through the spring washer  20 . 
         [0069]    3) As shown in  FIGS. 9(   a ),  9 ( b ) and  10 , the cord tube  14  is further moved toward the receptacle connector  80 , to allow the protrusion  66  provided on the outer surface of the connector member  12  to be brought into collision with the front wall  72  of the LC knob  62  defining the front opening of the through-hole  69 , so that the connector member  12  supported by the LC knob  62  is moved closer to the LC adapter  81  through the collision. 
         [0070]    4) As shown in  FIGS. 11(   a ),  11 ( b ) and  12 , the cord tube  14  is further moved toward the receptacle connector  80 , to allow the cantilever beam portion  61  of the connector member  12  to be engaged with the corresponding lock portion  87  of the LC adapter  81  through elastic displacement thereof, so that the connector member  12  is fitted into the LC adapter  81  and locked thereto. 
         [0071]    5) Finally, the joining member  18  is rotated in a clockwise direction (the arrowed direction “d”) and fixed to the cylindrical portion  86  in a bayonet manner. 
         [0072]    With reference to  FIGS. 13(   a ) to  20 , a movement during the operation of releasing the connection between the plug connector  10  and the receptacle connector  80  will be described below. 
         [0073]    1) The joining member  18  is rotated in a counterclockwise direction (the arrowed direction “d”) to release the fixing of the cylindrical portion  86 . 
         [0074]    2) Then, as shown in  FIGS. 13(   a ),  13 ( b ) and  14 , the cord tube  14  is moved toward the side opposite to the receptacle connector  80  (the arrowed direction “c 2 ”) along the fitting direction of the connector member  12  and the LC adapter  81 , to allow the joining member  18  supported by the cord tube  14  to be moved away from the cylindrical portion  86 , and allow the a front surface  78  of the inner wall of the concave portion  33  of the cord tube  14  to be brought into contact with the front surface  49  of the spring washer  20 , so that the spring washer  20  is integrally moved together with the cord tube  14 . 
         [0075]    3) As shown in  FIGS. 15(   a ),  15 ( b ) and  16 , the cord tube  14  is further moved toward the side opposite to the receptacle connector  80 , to allow a rear surface  48  of the spring washer  20  to be brought into contact with a rear surface  71  of the inner wall of the concave portion  30  of the LC knob  62 , so that the LC knob  62  supported by the cord tube  14  is moved away from the connector member  12 . 
         [0076]    4) Thus, as shown in  FIGS. 17(   a ),  17 ( b ) and  18 , the tab  67  of the LC knob  62  is brought into contact with the free end  76  of the cantilever beam portion  61 , so that the cantilever beam portion  61  is pushed downwardly (in the arrowed direction “h”) through the contact, and the locked state between the LC adapter  81  and the connector member  12  is released. 
         [0077]    5) As shown in  FIGS. 19(   a ),  19 ( b ) and  20 , the cord tube  14  is further moved toward the side opposite to the receptacle connector  80 , to allow the collision member  64  provided at the rear end of the connector member  12  to be brought into collision with the rear wall of the LC knob  62  defining the rear opening of the through-hole  69 , so that the connector member  12  supported by the LC knob  62  is moved away from the LC adapter  81  through the collision, and the fitting between the connector member  12  and the LC adapter  81  is released. 
         [0078]    In the waterproof device according to this embodiment, in the operation of connecting the plug connector  10  to the receptacle connector  80 , the connector member  12  can be fitted into the LC adapter  81 , and the joining member  18  can be connected to the cylindrical portion  87  (or fixed to the cylindrical portion  87  by a bayonet connection), through a single-step operation of moving the cord tube  14  with respect to the connector member  12 . Further, in the operation of releasing the connection between the plug connector  10  and the receptacle connector  80 , the bayonet connection between the joining member  18  and the cylindrical portion  86  can be released, and the fitting between the connector member  12  and the LC adapter  18  can be released, through a single-step operation of moving the cord tube  14  with respect to the connector member  12 . As above, in the above embodiment, although it is necessary to rotate the joining member in order to release the bayonet lock, the plug connector  10  can be connected to the receptacle connector  80 , and the connection therebetween can be released, through a single-step operation. Particularly, the unlocking of the connector member  12  provided in the plug connector  10  can be achieved only by a “pull-out operation”. Thus, it can be said that the waterproof device according to the above embodiment has excellent operating efficiency. In addition, the fitting between the connector member  12  and the LC adapter  81  can be released in a usual manner, although it is performed using the LC knob  62 . This also provides an advantage of being able to facilitate checking the release of the locked state. 
         [0079]    The present invention can be applied to not only a waterproof connector but also various other types of connectors.