Abstract:
A latching mechanism, which is configured to enable a pluggable optical transceiver module assembly to be plugged in or unplugged from a cage, is disclosed. The pluggable optical transceiver module assembly includes a bail clip for providing a latching portion locked in a locking member and an optical transceiver module having a connector portion including receptacle portions for accommodating external connectors. The bail clip includes a main body assembled through first and second ends of the connector portion; a lock pin, which is supported by a first end portion of the main body, has the latching portion exposed from or sunk in the second end of the connector portion, and provides a force of restitution to the bail clip; and a bail, one end of which is supported by a second end portion of the main body and which is laid on the first end of the connector portion in a lever shape, sinks the latching portion by giving pressure to the other end, and exposes the latching portion using the force of restitution of the lock pin by removing the pressure from the other end.

Description:
CLAIM OF PRIORITY  
       [0001]     This application claims priority under 35 U.S.C. § 119 to an application entitled “Pluggable Optical Transceiver Module Assembly,” filed in the Korean Intellectual Property Office on Sep. 13, 2004 and assigned Serial No. 2004-72980, the contents of which are incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates generally to a pluggable optical transceiver module assembly, and in particular, to a latching mechanism that is configured to enable the pluggable optical transceiver module assembly to be plugged in or unplugged from a cage.  
         [0004]     2. Description of the Related Art  
         [0005]     With the development of information and communication technologies, high data rate optical communication systems that only use a few communication lines have been developed in order to transmit more information. An optical communication system includes an optical transceiver module for electro-optic conversion and photoelectric conversion. The optical transceiver module includes a light source and an optical detection element. A small form-factor pluggable (SFP) optical transceiver module out of pluggable optical transceiver modules is well known. The SFP optical transceiver module interfaces a host device with an optical fiber cable.  
         [0006]     U.S. Pat. No. 6,439,918 entitled “Electronic Module Having an Integrated Latching Mechanism” discloses a latching mechanism used for an SFP optical transceiver module. In order to unplug the SFP optical transceiver module from a cage, an optical fiber connector to which optical fiber cable is connected should be first withdrawn from the SFP optical transceiver module. The SFP optical transceiver module should be pulled in a state where a bail of the latching mechanism is lifted. Since the bail covers the optical fiber connector, the optical fiber connector should be first withdrawn in order to lift the bail.  
         [0007]     As described above, the conventional latching mechanism has a structure in which an optical transceiver module cannot be unplugged from a cage in a state in which an optical fiber connector is inserted in the optical transceiver module.  
         [0008]     However, since the case where the optical fiber connector should be withdrawn from the cage for test and maintenance activities frequently occurs, in this environment, the conventional latching mechanism is very inconvenient to users.  
       SUMMARY OF THE INVENTION  
       [0009]     One aspect of the present invention relates to a pluggable optical transceiver module that is configured to enable an pluggable optical transceiver module to be unplugged from a cage in a state in which an optical fiber connect is inserted, and a pluggable optical transceiver module assembly using the same.  
         [0010]     One embodiment of the present invention is directed to a optical transceiver module assembly that can be plugged in a cage, which is installed in a corresponding port of a host device and has a locking member. The assembly includes a bail clip for providing a latching portion locked in a locking member and an optical transceiver module having a connector portion including receptacle portions for accommodating external connectors. The bail clip includes a main body assembled through first and second ends of the connector portion; a lock pin, which is supported by a first end portion of the main body, has the latching portion exposed from or sunk in the second end of the connector portion, and provides a force of restitution to the bail clip; and a bail, one end of which is supported by a second end portion of the main body and which is laid on the first end of the connector portion in a lever shape, sinks the latching portion by giving pressure to the other end, and exposes the latching portion using the force of restitution of the lock pin by removing the pressure from the other end.  
         [0011]     Another embodiment of the present invention is directed to a optical transceiver module assembly that can be plugged in a host device having a locking member. The assembly includes a bail clip for providing a latching portion locked in the locking member; a connector portion having a receptacle portion for accommodating an external connector; and a base portion, which is extended from the connector portion and accommodates a circuit for interfacing the host device with the external connector. The bail clip includes a main body assembled through first and second ends of the connector portion; a lock pin, which is supported by a first end portion of the main body, has the latching portion exposed from or sunk in the second end of the connector portion, and provides a force of restitution to the bail clip; and a bail, one end of which is supported by a second end portion of the main body and which is laid on the first end of the connector portion in a lever shape, sinks the latching portion by giving pressure to the other end, and exposes the latching portion using the force of restitution of the lock pin by removing the pressure from the other end. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]     The above and other aspects, features and embodiments of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings in which:  
         [0013]      FIG. 1  is a perspective view of a pluggable optical transceiver module assembly according to a first embodiment of the present invention;  
         [0014]      FIG. 2  is a perspective view of a cage and the pluggable optical transceiver module assembly shown in  FIG. 1 ;  
         [0015]      FIG. 3  is a top perspective view of a connector portion, from which a bail clip is disassembled, shown in  FIG. 1 ;  
         [0016]      FIG. 4  is a bottom perspective view of the connector portion, from which the bail clip is disassembled, shown in  FIG. 1 ;  
         [0017]      FIG. 5  is a cross-sectional view of the connector portion shown in  FIG. 3 , such as taken along A-A′, which divides the width into halves;  
         [0018]      FIG. 6  is a perspective view of the bail clip shown in  FIG. 1 ;  
         [0019]      FIG. 7  is a top perspective view of a connector portion, with which a bail clip is assembled, shown in  FIG. 1 ;  
         [0020]      FIG. 8  is a bottom perspective view of the connector portion shown in  FIG. 7 ;  
         [0021]      FIG. 9  is a cross-sectional view of the connector portion shown in  FIG. 7 , such as taken along B-B′, which divides the width into halves;  
         [0022]      FIG. 10  is a cross-sectional view illustrating an operating method of the bail clip shown in  FIG. 9 ;  
         [0023]      FIG. 11  is a cross-sectional view illustrating a state in which the pluggable optical transceiver module assembly shown in  FIG. 1  is engaged with the cage;  
         [0024]      FIG. 12  is a cross-sectional view illustrating a state in which the pluggable optical transceiver module assembly shown in  FIG. 1  is disengaged from the cage;  
         [0025]      FIG. 13  is a top perspective view of a connector portion from which a bail clip is disassembled according to a second embodiment of the present invention;  
         [0026]      FIG. 14  is a bottom perspective view of the connector portion shown in  FIG. 13 ;  
         [0027]      FIG. 15  is a cross-sectional view of the connector portion shown in  FIG. 13 , such as taken along C-C′, which divides the width into halves;  
         [0028]      FIG. 16  is a perspective view of the bail clip according to the second embodiment of the present invention;  
         [0029]      FIG. 17  is a perspective view illustrating a state in which the bail clip shown in  FIG. 16  is assembled with the connector portion shown in  FIG. 13 ;  
         [0030]      FIG. 18  is a bottom perspective view of the connector portion shown in  FIG. 17 ;  
         [0031]      FIG. 19  is a cross-sectional view of the connector portion shown in  FIG. 17 , such as taken along D-D′, which divides the width into halves;  
         [0032]      FIG. 20  is a cross-sectional view illustrating an operating method of the bail clip shown in  FIG. 19 ;  
         [0033]      FIG. 21  is a cross-sectional view illustrating a state in which the pluggable optical transceiver module assembly according to the second embodiment of the present invention is engaged with a cage; and  
         [0034]      FIG. 22  is a cross-sectional view illustrating a state in which the pluggable optical transceiver module assembly shown in  FIG. 21  is disengaged from the cage.  
     
    
     DETAILED DESCRIPTION  
       [0035]     Embodiments of the present invention will be described herein below with reference to the accompanying drawings. In the drawings, the same or similar elements are denoted by the same reference numerals even though they are depicted in different drawings. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail.  
         [0036]      FIG. 1  is a perspective view of a pluggable optical transceiver module assembly  100  according to a first embodiment of the present invention. Referring to  FIG. 1 , the pluggable optical transceiver module assembly  100  includes a pluggable optical transceiver module  110  and a metal case  150 . Hereinafter, an x-axis direction denotes a thickness direction of the pluggable optical transceiver module  110 , a y-axis direction denotes a width direction of the pluggable optical transceiver module  110 , and a z-axis direction denotes a length direction of the pluggable optical transceiver module  110 .  
         [0037]     The pluggable optical transceiver module  110  includes a connector portion  200  for accommodating optical fiber connectors, a base portion  120 , which is extended in the z-axis direction from a rear portion of the connector portion  200 , and a bail clip  400 , which is assembled with the connector portion  200  and is a latching mechanism. A printed circuit board (PCB)  130  having an edge connector  135  is assembled with the base portion  120 , and the edge connector  135  is connected to an electrical connector located at a corresponding port of a host device (not shown). Also, a bi-directional optical sub assembly (BiDi OSA)  140  is assembled with the base portion  120 . The BiDi OSA  140  includes a transmitter optical assembly  142  for electro-optic conversion and a receiver optical assembly  144  for photoelectric conversion.  
         [0038]     In this embodiment, the metal case  150  has a rectangular frame structure in which the front end, the rear end, and the bottom end are open and has a plurality of fixing members  152 ,  154 , and  156  on the top surface and both side surfaces. The metal case  150  covers the base portion  120  of the pluggable optical transceiver module  110 .  
         [0039]      FIG. 2  is a perspective view of a cage  500  and the pluggable optical transceiver module assembly  100  shown in  FIG. 1 .  
         [0040]     The cage  500  is assembled with a corresponding port of the host device and has a rectangular frame structure in which the front end and the rear end are open. An open portion is provided in the rear edge of the bottom portion of the cage  500 . The cage  500  has a plurality of fixing members  512 ,  514 , and  516  on the top portion. Also, in the bottom portion of the cage  500 , the cage  500  has a leaf spring  520 , which has a locking hole  525  to lock a lock pin  420  of the bail clip  400  therein, and first and second grooves  530  and  535  for providing the leaf spring  520  to the bottom portion of the cage  500 .  
         [0041]     The leaf spring  520  is formed by the first and second grooves  530  and  535 , which are abreast provided to the bottom portion of the cage  500 . The first and second grooves  530  and  535  extend in a direction from the front end to the rear end with a predetermined length and width. The first and second grooves  530  and  535  may has a shape in which the top end, the bottom end, and the front end are open. The locking hole  525  has a triangular shape is formed in the leaf spring  520 .  
         [0042]     The pluggable optical transceiver module assembly  100  can be inserted into the front end of the cage  500  from the rear end of the pluggable optical transceiver module assembly  100  and engaged with the cage  500  by locking the lock pin  420  of the bail clip  400  in the locking hole  525 . When the pluggable optical transceiver module assembly  100  is disengaged from the cage  500 , the pluggable optical transceiver module assembly  100  is pulled out in the x-axis direction in a state where the lock pin  420  of the bail clip  400  is unlocked from the locking hole  525 . When the pluggable optical transceiver module assembly  100  is disengaged from the cage  500 , optical fiber connectors inserted in first and second receptacle portions  240  and  245  do not have to be withdrawn.  
         [0043]      FIG. 3  is a perspective view of only the connector portion  200  of the pluggable optical transceiver module  110 , in which a top portion  250  of the connector portion  200  is shown.  
         [0044]      FIG. 4  is a perspective view of only the connector portion  200  of the pluggable optical transceiver module  110 , in which a bottom portion  210  of the connector portion  200  is shown.  
         [0045]      FIG. 5  is a cross-sectional view of the connector portion  200  of the pluggable optical transceiver module  110  shown in  FIG. 3 , such as taken along A-A′, which divides the width into halves.  
         [0046]     The connector portion  200  has a structure of symmetrical right and left halves along the y-axis direction and has a rectangular box shape, the front end of which is open. The connector portion  200  includes the bottom portion  210 , first and second side portions  220  and  225  extended upward from both side ends of the bottom portion  210 , a rear portion  290  closing the rear end of the connector portion  200 , the top portion  250 , which is extended from the rear end of the connector portion  200 , closes a portion of the top end of the connector portion  200 , and has the shape of c, and a center portion  230 , which is extended upward from the bottom portion  210  at a location at which the width of the connector portion  200  is equally divided into two halves. Due to the center portion  230 , the first receptacle portion  240  is provided between the center portion  230  and the first side portion  220 , and the second receptacle portion  245  is provided between the center portion  230  and the second side portion  225 . Also, the connector portion  200  further includes a second stopper  260 , which is extended from the first side portion  220  to the center portion  230  and upward protruded to make a height-level difference at the front end of the top portion  250 , a third stopper  265 , which is extended from the second side portion  225  to the center portion  230  and upward protruded to make a height-level difference at the front end of the top portion  250 , a first stopper  280 , which is upward protruded from the top surface of the center portion  230  and extended from the front end of the center portion  230  in the z-axis direction, and a projection  270 , which is upward protruded from the top surface of the center portion  230  and formed in a second accommodating space  267  between sections of the second and third stoppers  260  and  265  facing each other.  
         [0047]     Since the top portion  250  has the shape of c, a first accommodating space  255  for accommodating the bail clip  400  is provided, and one end of the first accommodating space  255  is closed by the second and third stoppers  260  and  265  and the projection  270 . A third accommodating space is provided between the projection  270  and the first stopper  280 .  
         [0048]     The center portion  230  includes a round-shaped first hole  235  extended from the top end of the center portion  230  to the bottom end, and the first hole  235  communicates with the first accommodating space  255 .  
         [0049]     The bottom portion  210  includes a rectangular-shaped second hole  215 , and the second hole  215  communicates with the first hole  235 .  
         [0050]     The rear portion  290  includes a rectangular-shaped third hole  292  at the lower part of the rear portion  290 , and the third hole  292  communicates with the second hole  215 . The rear portion  290  includes round-shaped fourth and fifth holes  294  and  296  locating apart from each other, the fourth hole  294  communicates with the first receptacle portion  240 , and the fifth hole  296  communicates with the second receptacle portion  245 .  
         [0051]     The connector portion  200  extend in the z-axis direction from the rear end of the rear portion  290  and further includes first and second guides  310  and  315 , which extend in the shape of a W from locations apart from the fourth and fifth holes  294  and  296 . In this embodiment, each of the first and second guides  310  and  315  has a half circular shape.  
         [0052]     The connector portion  200  further includes third and fourth guides  320  and  325 , which extend in the z-axis direction from the rear ends of the first and second guides  310  and  315  and extend in the shape of a W to make a height-level difference from the first and second guides  310  and  315 . In this embodiment, each of the third and fourth guides  320  and  325  has a half circular shape.  
         [0053]      FIG. 6  is a perspective view of the bail clip  400 . The bail clip  400  includes a main body  410  having the shape of a T, a bail  430  through which a first end portion of the main body  410  is assembled, a lock pin  420 , which is hooked on a second end portion of the main body  410 , and a fixing member  440 .  
         [0054]     In this embodiment, the main body  410  generally has the shape of a T and includes a body portion  412  having a round rod shape, a fixing portion  418 , which is formed at a first end portion of the body portion  412  and has a screw thread formed on the surface of the fixing portion  418 , first and second supporting portions  414  and  416 , which are formed at a second end portion of the body portion  412  and are linearly extended so as to be perpendicular to the body portion  412 . In this embodiment, each of the first and second supporting portions  414  and  416  has a round rod shape.  
         [0055]     The bail  430  includes a ring portion  432  having a round ring shape, a connecting portion  434 , which is bent and extended in a diameter direction from the side of the ring portion  432 , and a pressing portion  436 , which is connected to the end of the connecting portion  434 , has folds on one end, and has a rectangular block shape. The pressing portion  436  is connected to the connecting portion  434  so that the folds are located on the top position.  
         [0056]     The fixing member  440  can be screwed to the fixing portion  418  of the main body  410  (screwing method) and limits movement of the bail  430 . In a state in which the body portion  412  of the main body  410  is assembled through the ring portion  432  of the bail  430 , the movement of the bail  430  in one direction is limited by the first and second supporting portions  414  and  416 , and the movement of the bail  430  in the other direction is limited by the fixing member  440 .  
         [0057]     The lock pin  420  includes a latching portion  428  having a plate shape, an elastic portion  422 , which extends to slope outward from the surface of the latching portion  428  in a direction from a first end of the latching portion  428  to a second end and the end portion of which is bent, and first and second hooking portions  424  and  426 , which curve in the shape of a C in a direction from the second end of the latching portion  428  to the first end and are extended apart from each other. The elastic portion  422  has elasticity and can be curved in a direction of the first end of the latching portion  428 .  
         [0058]      FIG. 7  is a perspective view of only the connector portion  200  of the pluggable optical transceiver module  110  with which the bail clip  400  is assembled, in which the top portion  250  of the connector portion  200  is shown.  
         [0059]      FIG. 8  is a perspective view of only the connector portion  200  of the pluggable optical transceiver module  110  with which the bail clip  400  is assembled, in which the bottom portion  210  of the connector portion  200  is shown.  
         [0060]      FIG. 9  is a cross-sectional view of the connector portion  200  of the pluggable optical transceiver module  110  shown in  FIG. 7 , such as taken along B-B′, which divides the width into halves.  
         [0061]     An assembling sequence of the bail clip  400  will now be described.  
         [0062]     First, the bent portion of the elastic portion  422  of the lock pin  420  is inserted into the third hole  292  of the connector portion  200  and fixed.  
         [0063]     Second, the main body  410  is inserted into the connector portion  200  so that the fixing portion  418  of the main body  410  passes through between the first and second hooking portions  424  and  426  of the lock pin  420  and through the first hole  235  of the connector portion  200  and is exposed from the top of the center portion  230 .  
         [0064]     Third, the bail  430  is assembled with the main body  410  so that the main body  410  passes through the ring portion  432  of the bail  430 .  
         [0065]     Fourth, the fixing member  440  is fixed to the fixing portion  418  of the main body  410 .  
         [0066]     As shown in  FIG. 9 , the main body  410  passes through the first hole  235 , and the ring portion  432  of the bail  430  and the fixing member  440  are piled up on the top of the center portion  230 . The bail  430  is laid on the first accommodating space  255  and the second accommodating space  267 , and the pressing portion  436  of the bail  430  is placed in the third accommodating space between the projection  270  and the first stopper  280 . The connecting portion  434  of the bail  430  is laid on the projection  270 , and the pressing portion  436  is exposed from the top surface of the first stopper  280 . Also, a portion of the bail clip  400  placed in the first accommodating space  255  is exposed out of the first accommodating space  255 .  
         [0067]     The first and second hooking portions  424  and  426  of the lock pin  420  are hooked on the first and second supporting portions  414  and  416  of the main body  410 , respectively, and the latching portion  428  of the lock pin  420  is exposed out of the second hole  215  of the connector portion  200 .  
         [0068]      FIG. 10  is a cross-sectional view illustrating an operating method of the bail clip  400  shown in  FIG. 9 .If a user pushes the pressing portion  436  of the bail  430  downward using a finger, the ring portion  432  of the bail  430  is lifted to slope upward from the center portion  230  according to a lever principle. Since the ring portion  432  pushes the fixing member  440  upward, the main body  410  fixed to the fixing member  440  is moved upward. If the main body  410  moves upward, the latching portion  428  of the lock pin  420  is in the second hole  215  of the connector portion  200  by being moved upward by the first and second hooking portions  424  and  426  hooked on the first and second supporting portions  414  and  416  of the main body  410 . Before the movement, the latching portion  428  was exposed out of the second hole  215  of the connector portion  200 ; however, after the movement, the latching portion  428  is sunk into the second hole  215 . When the latching portion  428  and the first and second hooking portions  424  and  426  move upward, the elastic portion  422  is curved, and a force of restitution is generated. When the user takes the finger off from the pressing portion  436 , the bail clip  400  is restored as shown in  FIG. 9  by the force of restitution of the elastic portion  422 .  
         [0069]      FIGS. 11 and 12  illustrate methods of engaging the pluggable optical transceiver module assembly  100  with and disengaging it from the cage  500 .  FIG. 11  is a cross-sectional view illustrating a state in which the pluggable optical transceiver module assembly  100  is engaged with the cage  500 , and  FIG. 12  is a cross-sectional view illustrating a process of disengaging the pluggable optical transceiver module assembly  100  from the cage  500 .  
         [0070]     Referring to  FIG. 11 , the pluggable optical transceiver module assembly  100  is inserted into the front end of the cage  500  from the rear end of the pluggable optical transceiver module assembly  100  and engaged with the cage  500  by locking the lock pin  420  of the bail clip  400  in the locking hole  525 . The top portion of the cage  500  is apart from the top end of the connector portion  200  in order to provide space for the bail clip  400  exposed out of the first accommodating space  255  in an engaging process of the pluggable optical transceiver module assembly  100 . In the engaging process of the pluggable optical transceiver module assembly  100 , the front end of the cage  500  is contacted to the elastic portion  422  of the bail clip  400 .Since the elastic portion  422  slopes against the surface of the cage  500 , if the pluggable optical transceiver module assembly  100  is continuously pushed in the z-axis direction, the elastic portion  422  is curved, and the latching portion  428  is gradually sunk into the second hole  215 . If the pluggable optical transceiver module assembly  100  is further pushed in the z-axis direction, the latching portion  428  is completely sunk into the second hole  215 , and if the movement is stopped since the second and third stoppers  260  and  265  are contacted to the cage  500 , the latching portion  428  is exposed out of the second hole  215  and locked in the locking hole  525 .  
         [0071]     Referring to  FIG. 12 , if a user pushes the pressing portion  436  of the bail  430  downward using a finger, the latching portion  428  is completely sunk into the second hole  215  as described above. When the user pulls the pluggable optical transceiver module assembly  100  out in a state in which the latching portion  428  is completely sunk in the second hole  215 , the pluggable optical transceiver module assembly  100  is disengaged from the cage  500 .  
         [0072]      FIGS. 13 through 20  illustrate a pluggable optical transceiver module assembly according to a second embodiment of the present invention. Since the pluggable optical transceiver module assembly includes a case, which is the same as shown in  FIG. 1 , and a pluggable optical transceiver module in which only a connector portion  600  is different, duplicated drawings and descriptions are omitted.  
         [0073]     The pluggable optical transceiver module includes the connector portion  600  for accommodating an optical fiber connector, a base portion, which is extended in the z-axis direction from a rear portion of the connector portion  600 , and a bail clip  800 , which is assembled with the connector portion  600 . A PCB having an edge connector is assembled with the base portion, and the edge connector is connected to an electrical connector located at a corresponding port of a host device (not shown). A BiDi OSA is assembled with the base portion. The BiDi OSA includes a transmitter optical assembly for electro-optic conversion and a receiver optical assembly for photoelectric conversion.  
         [0074]      FIG. 13  is a perspective view of the connector portion  600  of the pluggable optical transceiver module, in which a top portion  640  of the connector portion  600  is shown.  
         [0075]      FIG. 14  is a perspective view of the connector portion  600  of the pluggable optical transceiver module, in which a bottom portion  610  of the connector portion  600  is shown.  
         [0076]      FIG. 15  is a cross-sectional view of the connector portion  600  of the pluggable optical transceiver module shown in  FIG. 13 , such as taken along C-C′, which divides the width into halves.  
         [0077]     The connector portion  600  has a structure of symmetrical right and left halves along the y-axis direction and has a rectangular box shape, the front end of which is open. The connector portion  600  includes the bottom portion  610  located at the bottom, first and second side portions  620  and  625  extend upward from both side ends of the bottom portion  610 , a rear portion  680  closing the rear end of the connector portion  600 , and the top portion  640 , which extends from the rear end of the connector portion  600 , closes a portion of the top end of the connector portion  600 , and has the shape of an E. A receptacle portion  630  is provided between the first side portion  620  and the second side portion  625 . The connector portion  600  further includes a second stopper  650 , which protrudes upwards from the first side portion  620  to make a height-level difference at the front end of the top portion  640 , a third stopper  655 , which protrudes upwards from the second side portion  625  to make a height-level difference at the front end of the top portion  640 , a first stopper  660 , which extends from the top surface of the first side portion  620  to the top surface of the second side portion  625 , a first projection  670 , which protrudes upwards from the top surface of the first side portion  620  and formed in a first accommodating space  652  between sections of the first and second stoppers  660  and  650  facing each other, and a second projection  675 , which protrudes upwards from the top surface of the second side portion  625  and formed in a second accommodating space  657  between sections of the first and third stoppers  660  and  655  facing each other.  
         [0078]     Since, in this embodiment, the top portion  640  has the shape of an E, first and second accommodating grooves  642  and  644  for accommodating the bail clip  800  is provided. The first accommodating groove  642  extends from the top end of the top portion  640  to the top surface of the first side portion  620 , and the second accommodating groove  644  extends from the top end of the top portion  640  to the top surface of the second side portion  625 . One end of the first accommodating groove  642  is closed by the first and second stoppers  660  and  650  and the first projection  670 , and one end of the second accommodating groove  644  is closed by the first and third stoppers  660  and  655  and the second projection  675 . Since, in this embodiment, the second stopper  650  is bent in the shape of an L, a third accommodating space is provided between the first projection  670  and the second stopper  650 , and since the third stopper  655  is also bent in the shape of an L, a fourth accommodating space is provided between the second projection  675  and the third stopper  655 .  
         [0079]     The first side portion  620  includes a round-shaped first hole  622  extended from the top end of the first side portion  620  to the bottom end, and the first hole  622  communicates with the first accommodating groove  642 . The second side portion  625  includes a round-shaped second hole  627  extended from the top end of the second side portion  625  to the bottom end, and the second hole  627  communicates with the second accommodating groove  644 .  
         [0080]     The bottom portion  610  includes a rectangular-shaped third hole  612 , and the third hole  612  communicates with the receptacle portion  630 . The bottom portion  610  further includes a third accommodating groove  614 , which extends in a predetermined depth from the bottom end of the bottom portion  610  in order to make the first hole  622  and the third hole  612  separated from each other communicate with each other, and a fourth accommodating groove  616 , which extends in a predetermined depth from the bottom end of the bottom portion  610  in order to make the second hole  627  and the third hole  612  separated from each other communicate with each other.  
         [0081]     The rear portion  680  includes a rectangular-shaped fourth hole  682  at the lower part of the rear portion  680 , and the fourth hole  682  communicates with the third hole  612 . The rear portion  680  also includes a round-shaped fifth hole  684 , and the fifth hole  684  communicates with the receptacle portion  630 .  
         [0082]     The connector portion  600  extends in the z-axis direction from the rear portion  680  and further includes a first guide  700 , which extends in the shape of a half circle from a location apart from the fifth hole  684 .  
         [0083]     The connector portion  600  further includes a second guide  710 , which extends in the z-axis direction from the rear end of the first guide  700  and extends in the shape of a half circle to make a height-level difference from the first guide  700 .  
         [0084]      FIG. 16  is a perspective view of the bail clip  800 . In this embodiment, the bail clip  800  includes a main body  810  having the shape of a U, a bail  830  through which both ends of the main body  810  is assembled, a lock pin  820 , which is hooked on a center portion of the main body  810 , and first and second fixing members  850  and  855 .  
         [0085]     In this embodiment, the main body  810  generally has the shape of a U and includes a body portion  812  having a round rod shape, a first fixing portion  814 , which is formed at a first end portion of the body portion  812  and has a screw thread formed on the surface of the first fixing portion  814 , and a second fixing portion  816 , which is formed at a second end portion of the body portion  812  and has a screw thread formed on the surface of the second fixing portion  816 .  
         [0086]     The bail  830  includes first and second ring portions  832  and  834  having a round ring shape, a first connecting portion  836 , which is bent and extended in a diameter direction from the side of the first ring portion  832 , a second connecting portion  838 , which is bent and extended in a diameter direction from the side of the second ring portion  834 , and a pressing portion  840 , which connects the first and second connecting portions  836  and  838 , has folds on one end, and has a rectangular block shape. The pressing portion  840  is connected to the first and second connecting portions  836  and  838  so that the folds are located on the top position.  
         [0087]     Movement of the bail  430  is limited by the first fixing member  850 , which can be screwed to the first fixing portion  814  of the main body  810 , and the second fixing member  855 , which can be screwed to the second fixing portion  816  of the main body  810 . In a state in which the body portion  812  of the main body  810  are assembled through the first and second ring portions  832  and  834  of the bail  430 , the movement of the bail  830  in one direction is limited by both bending portions of the body portion  812 , and the movement of the bail  430  in the other direction is limited by the first and second fixing members  850  and  855 .  
         [0088]     The lock pin  820  includes a latching portion  828  having a plate shape, an elastic portion  822 , which extends to slope outward from the surface of the latching portion  828  in a direction from a first end of the latching portion  828  to a second end and the end portion of which is bent, and first and second hooking portions  824  and  826 , which curve in the shape of a C in a direction from the second end of the latching portion  828  to the first end and extend apart from each other. The first and second hooking portions  824  and  826  are hooked on the center portion of the body portion  812 . The elastic portion  822  has elasticity and can be curved in a direction of the first end of the latching portion  828 .  
         [0089]      FIG. 17  is a perspective view of only the connector portion  600  of the pluggable optical transceiver module with which the bail clip  800  is assembled, in which the top portion  640  of the connector portion  600  is shown.  
         [0090]      FIG. 18  is a perspective view of only the connector portion  600  of the pluggable optical transceiver module with which the bail clip  800  is assembled, in which the bottom portion  610  of the connector portion  600  is shown.  
         [0091]      FIG. 19  is a cross-sectional view of the connector portion  600  of the pluggable optical transceiver module shown in  FIG. 17 , such as taken along D-D′, which divides the width into halves.  
         [0092]     An assembling sequence of the bail clip  800  will now be described.  
         [0093]     First, the bent portion of the elastic portion  822  of the lock pin  820  is inserted into the fourth hole  682  of the connector portion  600  and fixed.  
         [0094]     Second, the main body  810  is inserted into the connector portion  600  so that the first and second fixing portions  814  and  816  of the main body  810  pass through the first and second holes  622  and  627  of the connector portion  600  and are exposed from the top of the first and second side portions  620  and  625 , respectively.  
         [0095]     Third, the bail  830  is assembled with the main body  810  so that the main body  810  passes through the first and second ring portions  832  and  834  of the bail  830 .  
         [0096]     Fourth, the first fixing member  850  is fixed to the first fixing portion  814  of the main body  810 , and the second fixing member  855  is fixed to the second fixing portion  816  of the main body  810 .  
         [0097]     As shown in  FIG. 19 , the main body  810  passes through the second hole  627 , and the second ring portion  834  of the bail  830  and the second fixing member  855  are piled up on the top of the second side portion  625 . The bail  830  is laid on the second accommodating groove  644  and the second accommodating space  657 , and the pressing portion  840  of the bail  830  is placed in the third accommodating space between the second projection  675  and the third stopper  655 . The second connecting portion  838  of the bail  830  is laid on the second projection  675 , and the pressing portion  840  is exposed from the top surface of the third stopper  655 .A portion of the bail clip  800  placed in the second accommodating groove  644  is exposed out of the second accommodating groove  644 .  
         [0098]     The first and second hooking portions  824  and  826  of the lock pin  820  are hooked on the center portion of the main body  810 , and the latching portion  828  of the lock pin  820  is exposed out of the third hole  612  of the connector portion  600 .  
         [0099]      FIG. 20  is a cross-sectional view illustrating an operating method of the bail clip  800  shown in  FIG. 19 . Since  FIG. 19  is a cross-sectional view viewed in one direction, even if only a shown portion is described hereinafter, it will be understood that the same operation is also performed in a reverse direction.  
         [0100]     As shown in  FIG. 20 , if a user pushes the pressing portion  840  of the bail  830  downward using a finger, the second ring portion  834  of the bail  830  is lifted to slope upward from the second side portion  620  according to the lever principle. Since the second ring portion  834  pushes the second fixing member  855  upward, the main body  810  fixed to the second fixing member  855  is moved upward. If the main body  810  moves upward, the latching portion  828  of the lock pin  820  is in the third hole  612  of the connector portion  600  by being moved upward by the first and second hooking portions  824  and  826  hooked on the main body  810 . Before the movement, the latching portion  828  was exposed out of the third hole  612  of the connector portion  600 ; however, after the movement, the latching portion  828  is sunk into the third hole  612 . When the latching portion  828  and the first and second hooking portions  824  and  826  move upward, the second elastic portion  822  is curved, and a force of restitution is generated. When the user takes the finger off from the pressing portion  840 , the bail clip  800  is restored as shown in  FIG. 19  by the force of restitution of the elastic portion  822 .  
         [0101]      FIGS. 21 and 22  illustrate methods of engaging the pluggable optical transceiver module assembly with and disengaging it from a cage.  FIG. 21  is a cross-sectional view illustrating a state in which the pluggable optical transceiver module assembly is engaged with the cage, and  FIG. 22  is a cross-sectional view illustrating a process of disengaging the pluggable optical transceiver module assembly from the cage. Since the cage is equal to the cage  500  shown in  FIG. 2 , the same reference number is used. Also, since  FIGS. 21 and 22  are cross-sectional views viewed in one direction, even if only shown portions are described hereinafter, it will be understood that the same operations are also performed in a reverse direction.  
         [0102]     Referring to  FIG. 21 , the pluggable optical transceiver module assembly is inserted into the front end of the cage  500  from the rear end of the pluggable optical transceiver module assembly and engaged with the cage  500  by locking the lock pin  820  of the bail clip  800  in the locking hole  525 . The top portion of the cage  500  is apart from the top end of the connector portion  600  in order to provide space for the bail clip  800  exposed out of the second accommodating space  657  in an engaging process of the pluggable optical transceiver module assembly. In the engaging process of the pluggable optical transceiver module assembly, the front end of the cage  500  is contacted to the elastic portion  822  of the bail clip  800 .Since the elastic portion  822  slopes against the surface of the cage  500 , if the pluggable optical transceiver module assembly is continuously pushed in the z-axis direction, the elastic portion  822  is curved, and the latching portion  828  is gradually sunk into the third hole  612 . If the pluggable optical transceiver module assembly is further pushed in the z-axis direction, the latching portion  828  is completely sunk into the third hole  612 , and if the movement is stopped since the first through third stoppers  660 ,  650 , and  655  are contacted to the cage  500 , the latching portion  828  is exposed out of the third hole  612  and locked in the locking hole  525 .  
         [0103]     Referring to  FIG. 22 , if a user pushes the pressing portion  840  of the bail  830  downward using a finger, the latching portion  828  is completely sunk into the third hole  612  as described above. When the user pulls the pluggable optical transceiver module assembly out in a state in which the latching portion  828  is completely sunk in the third hole  612 , the pluggable optical transceiver module assembly is disengaged from the cage  500 .  
         [0104]     As described above, a pluggable optical transceiver module having a latching mechanism based on the lever principle and the pluggable optical transceiver module assembly using the same, can be unplugged from a cage in a state in which an optical connector is connected to the pluggable optical transceiver module.  
         [0105]     While the invention has been shown and described with reference to a certain embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.