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You are an expert at summarizing long articles. Proceed to summarize the following text: 
RELATED APPLICATIONS 
     This application claims priority to Taiwan Application Serial Number 97135858, filed Sep. 18, 2008, which are herein incorporated by reference. 
     BACKGROUND 
     1. Field of Invention 
     The present invention relates to a drawer latch mechanism. More particularly, the present invention relates to a latch mechanism of a drawer for accommodating removable sever hard drives. 
     2. Description of Related Art 
       FIG. 1  illustrates a conventional drawer latch mechanism, which has two parallel guide columns  21  located on a front edge  20  of a drawer. A latch member  10  has two guide slots  11  to respectively engage with two guide columns  21  such that the latch member  10  can be slid along the front edge  20  of the drawer back and forth to lock or unlock the drawer to a drawer shelf. 
     The latch member  10  has a handle  12  for users to be exerted force upon such that the latch member  10  can be pulled against a resilient spring  14  to unlock the drawer. The handle  12  needs to be long enough at least for fingers to exert force upon such that the handle  12  usually occupies more space. For the forgoing reasons, there is a need for improving the drawer latch mechanism. 
     SUMMARY 
     It is therefore an objective of the present invention to provide an improved drawer latch mechanism. 
     In accordance with the foregoing and other objectives of the present invention, a drawer latch mechanism is provided for securing a drawer to a lock hole of a drawer shelf. The drawer latch mechanism includes a latch member, a resilient recovery unit, a first horizontally positioning, a second horizontally positioning unit and a swivel member. The latch member includes the following components. A front portion is disposed in contact with a front edge of the drawer. An extension portion is connected to the front portion and extends along a lateral edge of the drawer. A latch end is bent from the extension portion to be inserted into the lock hole of the drawer shelf. Two slots are formed at one end of the front portion. The resilient recovery unit is disposed on the front portion and the front edge of the drawer to provide a recovery force to the latch member. The first horizontally positioning unit is disposed on the front portion and the front edge of the drawer to limit the latch member to slide back and forth along the front edge of the drawer. The second horizontally positioning unit is disposed on the extension portion and the lateral edge of the drawer to further limit the latch member to slide back and forth along the front edge of the drawer. The swivel member is pivotally connected with the front edge of the drawer and coupled with the two slots to drive the latch member against the recovery force so as to pull the latch end out of the lock hole of the drawer shelf. 
     Thus, the present invention provides a drawer latch mechanism, which is equipped with a swivel member to exert a force to slide the latch member. The swivel member is designed to be long enough to increase drive force toward the latch member and can be laid against the swivel member to occupy less space when the latch member is not used to drive the latch member. 
     It is to be understood that both the foregoing general description and the following detailed description are by examples, and are intended to provide further explanation of the invention as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings are included to provide a further to understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. In the drawings, 
         FIG. 1  illustrates a conventional drawer latch mechanism; 
         FIG. 2  illustrates an exploded view of a drawer latch mechanism according to one preferred embodiment of this invention; 
         FIG. 3  illustrates the drawer latch mechanism in  FIG. 2  in an assembly status; and 
         FIG. 4  and  FIG. 5  illustrates two operation statuses of a drawer latch mechanism according to one preferred embodiment of this invention. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Reference will now be made in detail to the present preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts. 
       FIG. 2  illustrates an exploded view of a drawer latch mechanism according to one preferred embodiment of this invention.  FIG. 3  illustrates the drawer latch mechanism in  FIG. 2  in an assembly status. The drawer latch mechanism includes a latch member  100  assembled to a corner of a drawer  200 . The latch member  100  includes a front portion  110 , an extension portion  120 , a latch end  130  and two slots ( 115   a ,  115   b ) to form a single unitary component. The front portion  110  is disposed in contact with a front edge  210  to of the drawer  200 . The extension portion  120  bends from an end of the front portion  110  and extends along a lateral edge  220  of the drawer  200 . The latch end  130  bends from an end of the extension portion  120 . The extension portion  120  is substantially perpendicular to the front portion  110 , and the latch end  130  is substantially perpendicular to the extension portion  120 . Thus, the latch end  130  is substantially in parallel with the front portion  110 . The extension portion  120  and the two slots ( 115   a ,  115   b ) are disposed at two opposite ends of the front portion  110 . The two slots ( 115   a ,  115   b ) are formed on a pair of opposite protrusions ( 113   a ,  113   b ) at the end of the front portion  110 . 
     The front portion  110  has a latch housing  112 , which includes an accommodation space facing the front edge  210  of the drawer  200 . A side wall of the latch housing  112  protrudes out as a fastener  114 . The front portion  110  also has a guide slot  111 . The extension portion  120  is shorter than the front portion  110 , and has a guide hole  121  in its central section. 
     The latch end  130  is operable to be inserted into a lock hole  420  of a drawer shelf  400  (see  FIG. 4 ). The latch end  130  has inclined surface  131  to interfere with the wall  410  for easily inserted into the lock hole  420  when the latch end  130  is being inserted into the lock hole  420 . 
     A block  211  is located on the front edge  210  of the drawer  200  to be placed within the accommodation space of the latch housing  112 . A resilient spring  300 , which has an end secured to the block  211  and an opposite end against an inner wall of the latch housing  112 , is also disposed within the latch housing to provide a recovery force for the latch member  100  when the latch member  100  is pulled out of the lock hole  420  of the drawer shelf  400 . The block  211 , the latch housing  112  and the resilient spring  300  can be regarded as a resilient recovery unit for the drawer latch mechanism in the present invention. 
     A guide column  212  (such as a bolt) is screwed into a screw hole  212   a  on the front edge  210  of the drawer  200 . The guide column  212  engages with the guide slot  111  of the latch member  100  such that the latch member  100  can be slid back and forth along the front edge  210  of the drawer  200 . The guide column  212  and the guide slot  111  can be referred as a first horizontally positioning unit for the latch member  100 . 
     A protrusion column  221  is located on the lateral edge  220  of the drawer  200  to engage within the guide hole  120  of the latch member  100 . The protrusion column  221  has a round end for easily insert into the guide hole  121  such that the latch member  100  can be further guided to slide along the front edge  210  of the drawer  200  back and forth. The protrusion column  221  and the guide hole  120  can be regarded as a second horizontally positioning unit for the latch member  100  in addition to the first horizontally positioning unit. 
     The swivel member  213  can be a metallic wire of the symbol “           ”, which has a top section  213   a  pivotally connected with the front edge  210  of the drawer  200 , such that the swivel member  213  can be swiveled relative to the front edge  210 . The swivel member  213  is coupled with the two slots ( 115   a ,  115   b ) of two protrusions ( 113   a ,  113   b ) to drive the latch member  100  against a recovery force (of the resilient spring  300 ) so as to pull the latch end  130  out of the lock hole  420  of the drawer shelf  400 . The latch member  100  may be or may not be with to equipped the slot ( 115   a  or  115   b ) to be driven by the swivel member  213 . Without the slot ( 115   a  or  115   b ), the swivel member  213  is still properly coupled with the two protrusions ( 113   a ,  113   b ) to drive the latch member  100 . When the swivel member  100  is swiveled to be laid against the front portion  110 , the metallic wire of the symbol “         ” has its bottom section  213   b  engaging the is fastener  114  (as illustrated in  FIG. 4 ).
     The first and second horizontally positioning units are to guide and limit the latch member  100  to slide along the front edge  210  of the drawer  200  back and forth. The resilient recovery unit is to provide a recovery force for the latch member  100  to maintain the latch end  130  to engage into the lock hole  420  of the drawer shelf  400  such that the drawer  200  can be secured to the drawer shelf  400 . 
       FIG. 4  and  FIG. 5  illustrates two operation statuses of a drawer latch mechanism according to one preferred embodiment of this invention.  FIG. 4  illustrates a lock status of the latch member  100 . The resilient recovery unit provides a recovery force for the latch member  100  to insert the latch end  130  into the lock hole  420  of the drawer shelf  400 . In such lock status of the latch member  100 , the swivel member  213  did not exert any force to the two slots ( 115   a ,  115   b ) and the swivel member  213 , which is a metallic wire of the symbol “           ”, has its bottom section  213   b  engaging the fastener  114 . When the swivel member  100  is laid against the front portion  110 , the swivel member  100  occupies less space than a conventional handle  12  does (as illustrated in  FIG. 1 ).  FIG. 5  illustrates an unlock status of the latch member  100 . In such unlock status of the latch member  100 , the drawer  200  can be pulled out or pushed into the drawer shelf  400  at will. The swivel member  213  is swiveled upright relative to the front edge  210  of the drawer  200  to exert force to the two slots ( 115   a ,  115   b ) such that the latch member  100  is driven against the recovery force of the resilient spring  300  so as to pull the latch end  130  out of the lock hole  420  of the drawer shelf  400 .
     According to discussed embodiments, the present invention provides a drawer latch mechanism, which is equipped with a swivel member to exert a force to slide the latch member. The swivel member is designed to be long enough to increase drive force toward the latch member and can be laid against the swivel member to occupy less space when the latch member is not used to drive the latch member. 
     It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the present invention cover modifications and variations of this invention provided they fall within the scope of the following claims and their equivalents.

Summary:
This present invention relates to a drawer latch mechanism, implementing to a drawer for removable hard drives in a server computer. The drawer latch mechanism comprises a latch member, which extends from the front edge of the drawer to the lateral edge of the drawer. The latch member is installed on the front edge of the drawer to be moved back and forth thereon. The latch member is applied to insert to a corresponding a lock hole to secure the drawer to a drawer shelf. The drawer latch mechanism further comprises a swivel member to withdraw the latch member from the lock hole.