Abstract:
An extending latch mechanism for a pluggable optical module includes a resilient member and a lever coupling with each other. The lever is turnable to drive and deform the resilient member and to retract the resilient member transversely in the optical module so that the optical module may be removed directly. The structure is simple and easy to fabricate and assemble. It is reliable and convenient to use.

Description:
FIELD OF THE INVENTION 
   The present invention relates to a latch mechanism for a pluggable optical module and particularly to an extending latch mechanism for a pluggable optical module that is reliable and convenient to use. 
   BACKGROUND OF THE INVENTION 
   In optical communication applications, the optical transceiver is an important element in the photoelectric transforming interface. Signal transmission speed may range from 155 Mb/s to 1.25 Gb/s or even 10 Gb/s. Various types of packages are available depending on application environments, such as 1×9 pin, GBIC (GigaBit Interface Converter), SFF (Small Form Factor), SFP (Small Form Factor Pluggable), and the like. 1×9 pin and SFF adopt a fixed packaging method that is difficult to remove once the module is installed in the system. GBIC and SFP adopt a pluggable approach that can be removed and replaced after installing in the system. 
   In the design of the pluggable module, many factors have to be considered, such as electricity issues while plugging the module, reliability and convenience of the plugging mechanism. For instance, U.S. Pat. Nos. 6,439,918 and 6,533,603 assigned to Finisar Co. disclose a SFP module that has a latching mechanism ramming the bottom of the module through a lever to extend or retract the latching mechanism in the module. U.S. Pat. No. 6,494,623 assigned to Infineon Co. also discloses a SFP release mechanism which has a lever turnable to press a locking reed of a transceiver to extend a latch of the module to escape a locking reed for releasing the module. Those references mostly employ latch mechanisms that are complex and require expensive elements. They also are difficult to fabricate and assemble. 
   SUMMARY OF THE INVENTION 
   In order to solve the aforesaid disadvantages, the present invention aims is to provide an extending latch mechanism for a pluggable optical module that is simply structured, easy to fabricate and assemble, reliable and convenient to use. 
   The extending latch mechanism for a pluggable optical module according to the invention includes a holding trough, a resilient member and a lever. The holding trough is formed on the optical module and has two ends. Each end has a latch notch, an extracting channel and a sloped surface abutting the latch notch. The resilient member is, located in the holding trough and has one end forming a latch section extending outside the latch notch and another end forming a driving portion extending outside the extracting channel, and a contact portion formed in the middle portion matching the sloped surface. The optical module is anchored on an electronic device through the latch section. 
   The driving portion has one end coupled on the lever. When the lever is turned relative to the optical module, the resilient member is stretched outwards and deformed, and the bent contact portion slides on the sloped surface to retract the distal end of the latch section into the holding trough to enable the optical module to be removed from the electronic device. 
   The foregoing, as well as additional objects, features and advantages of the invention will be more readily apparent from the following detailed description, which proceeds with reference to the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a schematic view of the invention coupled with an optical module. 
       FIG. 2  is an exploded view of the invention coupled with an optical module. 
       FIG. 3  is a fragmentary exploded view of the invention coupled with an optical module. 
       FIGS. 4A through 6B  are schematic views of the invention in operating condition. 
       FIG. 7  is a schematic view of another embodiment of the invention coupled with an optical module. 
       FIGS. 8A and 8B  are schematic views of the invention shown in  FIG. 7  in operating condition. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   The extending latch mechanism according to the invention is applicable to any pluggable optical module such as an optical transceiver, light emitter, optical receiver, and the like. The following discussion is based on an optical transceiver. 
   Referring to  FIG. 1 , a latch mechanism  20  is adopted for use on an optical module  10  for selectively coupling the optical module  10  on an electronic device (not shown in the drawings). Also referring to  FIG. 2 , the optical module  10  includes an upper lid  11 , a circuit board  12  and a lower lid  13 . The latch mechanism  20  includes a lever  21 , a resilient member  22  and a holding trough. The lever  21  is located on the front end of the optical module  10 , and has a handle  211  and two struts  212  and  213  extended from two ends of the handle  211 . The struts,  212  and  213 , have a stub shaft,  2121  and  2131 . The resilient member  22  is made of a material which has a desired elasticity and resiliently, such as metal, plastic or the like. It has two distal ends forming latch sections,  221  and  222 , two bent contact portions,  224  and  223 , abutting the latch sections,  221  and  222 , and driving portions,  225  and  226 , extended from the contact portions to become an integrated member. A holding trough  23  is provided to match and hold the resilient member  22 . It has a first holding trough  231  and a second holding trough  232  matching the latch sections,  221  and  222 , and the contact portions,  224  and  223 . 
   The first holding trough  231  has two ends forming respectively a latch notch  2311  and an extracting channel  2312 , and a sloped surface  2313  in the middle close to the latch notch  2311 . Similarly, the second holding trough  232  has two ends forming respectively a latch notch  2321  and an extracting channel  2322 , and a sloped surface  2323  in the middle close to the latch notch  2321 . 
   Referring to  FIG. 3 , the resilient member  22  is held in the holding trough  23  with the latch sections,  221  and  222 , coupled on the latch notches,  2321  and  2311 , and extended outside to anchor the optical module  10  (also referring to  FIG. 1 ). The contact portions  223  and  224  press respectively the sloped surface  2313  of the first holding trough  231  and the sloped surface  2323  of the second holding trough  232 . The driving portions  225  and  226  at the front are extended outside the retracting channels,  2322  and  2312 , to couple on the stub shafts,  2121  and  2131 , of the lever  21 . 
   In normal condition, referring to  FIGS. 4A and 4B , the resilient member  22  and the lever  21  are engaged, and the contact portions,  223  and  224 , press the sloped surfaces,  2313  and  2323 , to keep the lever  21  substantially in an upright condition, abutting the edge of the optical module  10 , and the latch sections,  221  and  222 , are extended. 
   When the lever  21  is moved and turned about the stub shafts  2131  and  2121  relative to the optical module  10 , the distal ends of the struts  212  and  213  contact the edge of the optical module  10  as shown in  FIGS. 5A and 5B . As the distance L 1  between the distal ends of the struts,  212  and  213 , and the stub shafts,  2121  and  2131 , is greater than the distance L 2  of the stub shafts,  2121  and  2131 , and the optical module  10  (namely the distance between the lever  21  and the side wall surface of the optical module  10 , referring to  FIG. 4A ), when the lever  21  is turned continuously, it is urged by a reaction force to move the stub shafts,  2121  and  2131 , outwards. Referring to  FIGS. 6A and 6B , with the driving portions,  225  and  226 , of the resilient member  22  coupled on the stub shafts,  2121  and  2131 , the resilient member and the stub shafts also are moved outwards by the lever  21 , and the contact portions,  223  and  224 , are moved and slide on the sloped surfaces,  2313  and  2323 , to force the resilient member  22  to deform. As a result, the latch sections,  221  and  222 , at the distal ends are retracted from the latch notches,  2311  and  2321 , into the first holding trough  231  and the second holding trough  232 . Therefore the optical module  10  is separated from the electronic device. 
   Such a structure is simpler and requires fewer elements. It&#39;s cheaper. Fabrication and assembly also are easier. The resilient member  22  is not limited to the one shown in the drawings. It also may be a reed. The latch sections  221  and  222  also are not limited to extending outward. They may be formed in an up and down manner, or become a single latch section. 
   Refer to  FIG. 7  for another embodiment of the invention. The lever  21  adopts the same principle set forth above. However, the resilient member  22  is an elastic reed located on one side of the optical module. It has a jutting latch section  227  on one side and a sloped surface  228  nearby (referring to  FIG. 8A ). In normal conditions, the contact portion  223  presses the sloped surface  233 , and the latch section  227  latches in a latch trough  41  of an electronic device  40  to anchor the optical module on the electronic device  40 . Referring to  FIG. 8B , when the lever  21  is turned, the resilient member  22  is moved outwards and the contact portion  223  slides on the sloped surface  233  to deform the resilient member  22  so that the distal end of the latch section  227  is moved away from the latch trough  41 . 
   While the preferred embodiments of the invention have been set forth for the purpose of disclosure, modifications of the disclosed embodiments of the invention as well as other embodiments thereof may occur to those skilled in the art. Accordingly, the appended claims are intended to cover all embodiments, which do not depart from the spirit and scope of the invention.