Abstract:
A latch mechanism includes a latching member, a push member, and a sliding member. The latching member is slidably installed in a cover unit in parallel to a front wall thereof. The latching member includes a hook for engaging with a base unit. The push member is slidably installed in the cover unit parallel to a sidewall perpendicular to the front wall thereof. The sliding member is connectable with the push member, and is capable of being operated to drive the push member to push the latching member for disengaging the hook of the latching member from the base unit.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a latch mechanism, and more particularly to a latch mechanism for a portable computer. 
     2. Description of Related Art 
     Typically, an electronic device, such as a portable computer, includes a cover unit and a base unit pivotally connected with the cover unit, and a latch mechanism is provided to lock the cover unit to the base unit. 
     As disclosed in U.S. Pat. No. 6,115,239, a latch mechanism for locking a cover unit to a base unit of a portable computer, includes a latch frame movably installed inside the cover unit, a plurality of latches are formed on the latch frame at predetermined intervals and one end portion of each latch protrudes from a front surface of the cover unit, and a slide knob is operatively connected to the latch frame for concurrently operating the latches. The latches are inserted into and locked by latch grooves formed at positions corresponding to the latches on an upper surface of the base unit. The latches are urged against the base unit by elastic forces applied by double springs mounted on two ends of the latch frame. However, the latch frame and the slide knob are installed on a front end of the cover unit. To open the cover unit, the slide knob is slid to overcome the elastic forces of the springs to move the latch mechanism for disengaging from the base unit. Typically, the forces of sliding the slide knob and opening the cover unit depend on friction between the slide knob and a thumb of an operator at the front of the portable computer. It is laborious for an operator to provide enough force to move a slide knob and open the cover unit depending on only one finger at the front of the portable computer. 
     What is needed, therefore, is a laborsaving latch mechanism. 
     SUMMARY OF THE INVENTION 
     An exemplary latch mechanism includes a latching member, a push member, and a sliding member. The latching member is slidably installed in a cover unit in parallel to a front wall thereof. The latching member includes a hook for engaging with a base unit. The push member is slidably installed in the cover unit parallel to a sidewall perpendicular to the front wall thereof. The sliding member is connectable with the push member, and is capable of being operated to drive the push member to push the latching member for disengaging the hook of the latching member from the base unit. 
     Other advantages and novel features of the present invention will become more apparent from the following detailed description of a preferred embodiment when taken in conjunction with the accompanying drawings, in which: 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded, partially sectioned isometric view of a latch mechanism with a cover unit in accordance with a preferred embodiment of the present invention, and the latch mechanism includes a sliding member; 
         FIG. 2  is an enlarged isometric view of a circled portion II of  FIG. 1 ; 
         FIG. 3  is an enlarged isometric view of a circled portion III of  FIG. 1 ; 
         FIG. 4  is another aspect view of the sliding member of  FIG. 1 ; 
         FIG. 5  is an assembled, partially sectioned view of  FIG. 1 , but viewed from another aspect; 
         FIG. 6  is an assembled view of  FIG. 1 ; and 
         FIG. 7  is a schematic, assembled view of  FIG. 1  with a base unit. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to  FIGS. 1 to 5 , a latch mechanism is provided in accordance with a preferred embodiment of the present invention, for locking a cover unit to a base unit  50  (as shown in  FIG. 6 ) of an electronic device, such as a portable computer. The latch mechanism includes a sliding member  35 , a latching member  22 , a push member  24 , a first elastic member  42  for restoring the latching member  22 , and a second elastic member  44  for restoring the push member  24 . In this embodiment, the first elastic member  42  and the second elastic member  44  are coil springs. 
     The latching member  22  includes a bar-shaped body forming a slanted surface  226  on an end portion thereof. Two hooks  228  (see  FIG. 5 ) protrude from a bottom portion of the latching member  22 . A plurality of staggered notches  221  is defined in a front edge and a rear edge of the latching member  22 . Two spaced sliding slots  223  are defined in the latching member  22 , and a receiving recess  222  is defined in a middle portion of the latching member  22  between the sliding slots  223 . A post  224  (see  FIG. 3 ) extends from a portion of the latching member  22  bounding the receiving recess  222  into the receiving recess  222 . The post  224  is oriented generally along a longitudinal axis of the receiving recess  222  and is for the first elastic member  42  to be placed thereon. 
     A slanted engaging surface  246  is formed on a first end of the push member  24  contacting with the slanted surface  226  of the latching member  22 . Referring particularly to  FIG. 2 , a post  248  protrudes from a second end of the push member  24 . Two spaced sliding slots  244  are defined in the push member  24 , and a hooking opening  242  is defined in a middle portion of the push member  24  between the sliding slots  244 . A fixing hole  245  is defined in the push member  24 . 
     The cover unit includes a first panel  10  holding an electronic component such as a liquid crystal display (not labeled) therein, and a second panel  30 . The first panel  10  includes a front wall  11  (see  FIG. 3 ) and a sidewall  12  generally perpendicular to the front wall  11 . Referring to  FIG. 5 , two through holes  13  are defined in the first panel  10  adjacent the front wall  11 , corresponding to the hooks  228  of the latching member  22 . Referring to  FIGS. 1 and 3 , a plurality of staggered hooking members  14  is formed on an inside surface of the first panel  10  adjacent the front wall  11 , for engaging in the corresponding notches  221  of the latching member  22 . The inside surface of the first panel  10  adjacent the front wall  11  forms a first stop plate  16  and two positioning rods  15 , corresponding to the receiving recess  222  and the sliding slots  223  of the latching member  22  respectively. The inside surface of the first panel  10  adjacent the sidewall  12  forms a hooking member  17  and two positioning rods  18 , corresponding to the hooking opening  242  and the sliding slots  244  of the push member  24  respectively. Referring to  FIG. 2 , a second stop plate  19  is formed on the inside surface of the first panel  10  behind the hooking member  17  and the positioning rods  18 . Referring back to  FIG. 1 , the second panel  30  defines an opening  31  in a sidewall thereof, corresponding to the sidewall  12  of the first panel  30 . Two concave plates  32  are formed on the sidewall of the second panel  30  adjoining two sides of the opening  31 , for supporting the sliding member  35  to slide thereon. 
     Referring to  FIG. 4 , a fixing portion  352  extends from a bottom section of the sliding member  35 . Two latching portions  355  are formed on the bottom section of the sliding member  35  toward two ends of the sliding member  35  respectively. 
     Referring to  FIG. 7 , the base unit  50  defines a pair of latching slots  51 , corresponding to the hooks  228  of the latching member  22 . 
     Referring further to  FIGS. 1 ,  5  and  6 , in assembly, the first elastic member  42  is placed around the post  224  in the receiving recess  222  of the latching member  22 , the hooks  228  of the latching member  22  extend through the through holes  13  of the first panel  10  respectively. The slanted surface  226  of the latching member  22  is adjacent the sidewall  12  of the first panel  10 . The hooking members  14  of the first panel  10  adjacent the front wall  11  engage in the corresponding notches  221  of the latching member  22 , and the positioning rods  15  are received in the corresponding sliding slots  223 . The first stop plate  16  is received in the receiving recess  222  of the latching member  22 . One end of the first elastic member  42  abuts against the latching member  22 , and the other end of the first elastic member  42  abuts against the first stop plate  16 . The latching member  22  is thus slidably fixed to the first panel  10 . 
     Thereafter, the second elastic member  44  is placed around the post  248  of the push member  24 , the push member  24  is placed on the first panel  10  adjacent the sidewall  12 , with the engaging surface  246  of the push member  24  abutting against the slanted surface  226  of the latching member  22 . The hooking members  17  of the first panel  10  adjacent the sidewall  12  engage with the corresponding hooking opening  242  of the push member  24 , and the positioning rods  18  are received in the corresponding sliding slots  244  of the push member  24 . One end of the second elastic member  44  abuts against the push member  24 , and the other end of the second elastic member  44  abuts against the second stop plate  19 . 
     Finally, the sliding member  35  is mounted on the second panel  30 , and the plates  32  of the second panel  30  are sandwiched by the sliding member  35  and the corresponding latching portions  355 . The second panel  30  is fixed to the first panel  10  to cover one side of the liquid crystal display mounted in the first panel  10 , and the fixing portion  352  of the sliding member  35  is inserted into the fixing hole  245  of the push member  24  on the first panel  10 . Thereby, the cover unit is assembled, and the push member  24  is slidable with sliding of the sliding member  35  along the plates  32  of the second panel  30 . 
     Referring further to  FIG. 7 , the cover unit is pivotably attached to the base unit  50 . The cover unit is pivoted to cover the base unit  50  when the electronic device is not in use. When bottom surfaces of the hooks  228  abut against the portions adjoining the latching slots  51  of the base unit  50  respectively, the cover unit is further pressed down, and the latching member  22  is therefore pushed to compress the first elastic member  42  and slides away from the push member  24 , until the hooks  228  entirely enter the latching slots  51  respectively. After that, the first elastic member  42  is restored to push the latching member  22  to slide toward the push member  24 , and top surfaces of the hooks  228  engage with the portions of the base unit  50  adjoining the latching slots  51  respectively. Thus, the cover unit is locked to the base unit  50 . 
     To unlock the cover unit from the base unit  50 , the sliding member  35  is pushed toward a rear edge of the cover unit, and the fixing portion  352  of the sliding member  35  pushes the push member  24  to slide with the sliding member  35  in a direction along the sidewall  12  of the first panel  10 . The second elastic member  44  is compressed. The engaging surface  246  of the push member  24  abuts against the slanted surface  226  of the latching member  22 , and pushes the latching member  22  to slide in another direction along the front wall  11  perpendicular to the sidewall  12  of the first panel  10  and compresses the first elastic member  42 . When the hooks  228  of the latching member  22  move in the corresponding latching slots  51  and disengage from the portions adjoining the latching slots  51  respectively, the cover unit is ready to be pivoted open by grasping the front wall of the cover unit. After opening the cover unit, the sliding member  35  is released allowing the second elastic member  44  to restore the push member  24 . 
     It is believed that the present embodiment and its advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the example hereinbefore described merely being preferred or exemplary embodiment of the invention.