Abstract:
A latch mechanism includes a latching member and a button. The latching member is slidably installed in a cover unit. The latching member includes a hook for engaging with a base unit, a groove is defined in the latching member, and a slanted surface is defined adjoining the groove. The button is movably fixed to the cover unit. The button includes a pushing portion received in the groove of the latching member and engaging with the slanted surface adjoining the groove. The button can be operated to drive the latching member to slide for disengaging the hook from the base unit.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates to a latch mechanism, and more particularly to a latch mechanism for a portable computer.  
       DESCRIPTION OF RELATED ART  
       [0002]     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.  
         [0003]     As disclosed in U.S. Pat. No. 6,115,239, a latch mechanism for locking a cover unit to a base unit, 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, 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. The slide force depends on friction between the slide knob and fingers of an operator. It is laborious for an operator to provide enough force to move a slide knob.  
         [0004]     What is needed, therefore, is a laborsaving latch mechanism.  
       SUMMARY OF THE INVENTION  
       [0005]     An exemplary latch mechanism is provided for locking a cover unit to a base unit. The latch mechanism includes a latching member and a button. The latching member is slidably installed in the cover unit. The latching member includes a hook for engaging with the base unit, a groove is defined in the latching member, and a slanted surface is defined adjoining the groove. The button is movably fixed to the cover unit. The button includes a pushing portion received in the groove of the latching member and engagable with the slanted surface adjoining the groove. The button is operated to drive the latching member to slide for disengaging the hook from the base unit.  
         [0006]     Other advantages and novel features 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  
       [0007]      FIG. 1  is an exploded, isometric, inverted view of a latch mechanism with a cover unit in accordance with a preferred embodiment of the present invention, and the cover unit includes a first panel and a second panel;  
         [0008]      FIG. 2  an enlarged, assembled view of  FIG. 1  without the second panel of the cover unit;  
         [0009]      FIG. 3  is similar to  FIG. 2 , but showing another state of the latch mechanism; and  
         [0010]      FIG. 4  is a schematic, assembled and part-sectioned view of  FIG. 1  with a base unit.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0011]     Referring to  FIGS. 1 and 4 , a latch mechanism is provided in accordance with a preferred embodiment of the present invention, for locking a cover unit  10  to a base unit  50  of an electronic device, such as a portable computer. The latch mechanism includes a button  20 , a latching member  30 , and an elastic member  40 . In this embodiment, the elastic member  40  is a spring.  
         [0012]     The cover unit  10  includes a first panel  11 , and a second panel  13  having a pair of through holes  131  defined therein. The first panel  11  includes a front wall  111 , and a recess  112  is defined inward in the middle of the front wall  111 . A first plate  115  and a second plate  116  are formed oppositely on an inside surface of the first panel  11  adjacent to the front wall  111 . A first guiding hole  117  is defined in the first plate  115 , and a second guiding hole  118  is defined in the second plate  116  by cutting out a top portion thereof. Two pairs of sliding rails  119  are formed on the first panel  11  between the first plate  115  and the second plate  116 . The pairs of sliding rails  119  are parallel to the front wall  111 , and two pairs of sliding rails (not shown) are formed on an inside surface of the second panel  13  corresponding to the pairs of sliding rails  119  of the first panel  11 . A post  114  is formed perpendicularly on the first panel  11  between the pairs of sliding rails  119  adjacent to the recess  112 .  
         [0013]     The button  20  is generally T-shaped. The button  20  includes a press portion  21 , and a pushing portion  23  extending perpendicularly from a rear end of the press portion  21 . A longitudinal hole  25  is defined in the pushing portion  23  corresponding to the post  114  of the first panel  11 .  
         [0014]     The latching member  30  includes a main body  31 , a plurality of sliding slots  312  are defined in a bottom portion of the main body  31  corresponding to the sliding rails  119  of the first panel  11 , and a plurality of sliding slots  314  are defined in a top portion of the main body  31  corresponding to the sliding rails of the second panel  13 . The main body  31  includes a front surface  311 , and a notch  313  is defined by cutting into a middle portion of the front surface  311  corresponding to the post  114  of the first panel  11 . A groove  315  is defined in a middle section of the top portion of the main body  31  in communication with the notch  313 , and a slanted surface  317  adjoining the groove  315  is defined between the front surface  311  and a rear surface of the main body  31 . A pair of hooks  32  respectively having a hooking portion  321  protrude from the top portion of the main body  31 , corresponding to the through holes  131  of the second panel  13 . A first rod  33  and a second rod  34  extend from two opposite ends of the main body  31  respectively.  
         [0015]     The base unit  50  defines a pair of latching slots  51 , corresponding to the hooks  32  of the latching member  30 .  
         [0016]     Referring also to  FIGS. 2 and 3 , in assembly, the elastic member  40  is placed around the first rod  33  of the latching member  30 , and a free end of the first rod  33  extends through the first guiding hole  117  of the first plate  115  of the first panel  11 , with two free ends of the elastic member  40  respectively engaging with the main body  31  of the latching member  30  and the first plate  115  of the first panel  11 . The second rod  34  of the latching member  30  is pressed down into the second guiding hole  118  from the top portion of the second plate  116 . The sliding rails  119  of the first panel  11  are received in the sliding slots  312  in the bottom portion of the main body  31  of the latching member  30 , and the post  114  of the first panel  11  engages in the notch  313  of the main body  31 , thereby the latching member  30  is fixed to the first panel  11  and capable of sliding along the sliding rails  119 . The button  20  is mounted on the first panel  11  with the post  114  of the first panel  11  extending through the longitudinal hole  25  of the button  20 . The press portion  21  of the button  20  is exposed from the recess  112  of the front wall  111  of the first panel  11 , and the pushing portion  23  of the button  20  is received in the groove  315  of the latching member  30  and engages with the slanted surface  317  adjoining the groove  315 .  
         [0017]     Referring also to  FIG. 4 , the second panel  13  holds a Liquid Crystal Display therein, and the first panel  11  is fixed to the second panel  13  to cover one side of the Liquid Crystal Display. The hooks  32  of the latching member  30  extend outward from the through holes  131  of the second panel  13  respectively, thereby the cover unit  10  is fully assembled.  
         [0018]     The cover unit  10  is pivotably attached to the base unit  50 . The cover unit  10  is pivoted to cover the base unit  50  when the electronic device is not in use. When bottom surfaces of the hooking portions  321  of the hooks  32  abut against portions adjoining the latching slots  51  of the base unit  50  respectively, the cover unit  10  is downward pressed and the latching member  30  is therefore pushed to compress the elastic member  40  and slides toward the first plate  115  until the hooking portions  321  of the hooks  32  entirely enter the latching slots  51  respectively. After that the elastic member  40  is restored to push the latching member  30  to slide toward the second plate  116 , top surfaces of the hooking portions  321  of the hooks  32  engage with the portions of the base unit  50  adjoining the latching slots  51 . Thus, the cover unit  10  is locked to the base unit  50 .  
         [0019]     Referring further to  FIG. 3 , to unlock the cover unit  10  from the base unit  50 , the press portion  21  of the button  20  is pressed to move the button  20  along the post  114  in a first direction perpendicular to the front wall  111 . The pushing portion  23  of the button  20  actuates the slanted surface  317  of the latching member  30 , and the latching member  30  is therefore pushed to slide in a second direction perpendicular to the first direction toward the first plate  115  and compress the elastic member  40 . When the hooking portions  321  of the hooks  32  moves in corresponding latching slots  51  and disengage from the portions adjoining the latching slots  51  respectively, the cover unit  10  is ready to be pivoted open.  
         [0020]     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.