Abstract:
A mounting apparatus for mounting a motherboard ( 70 ) having several first mounting holes ( 73 ) includes a chassis ( 10 ), a fixing member ( 30 ), and a supporting member ( 50 ). The chassis comprised a post ( 13 ) protruding from a bottom wall ( 11 ) thereof, and a number of standoffs ( 17 ) received in first the mounting hole. The fixing member is slidably mounted to the post, and includes a first engaging portion ( 35 ) protruding from a middle portion thereof. The supporting member is attached to the motherboard, and includes a second engaging portion ( 57 ) projecting from an end thereof. When the first engaging portion of the fixing member engages with the second engaging portion of the supporting member, the motherboard is in a lock state; when the first engaging portion of the fixing member disengages from the second engaging portion of the supporting member, the motherboard is in an unlock state.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to mounting apparatuses for circuit boards, and particularly to a mounting apparatus that readily attach a circuit board onto a computer chassis. 
   2. Description of Related Art 
   For many years, the conventional method of installing a circuit board, such as a motherboard, in a computer was to simply screw the motherboard on a chassis of the computer. This motherboard installation method substantially increases the time and the cost because of the complexity and difficulty of assembled or disassembled. 
   A relatively recent improvement in the mounting of a motherboard in a computer is illustrated and described in U.S. Pat. No. 5,754,396. In this patent, the motherboard is mounted to a projection structure that can be slid into and out of a computer chassis to install and later remove the motherboard for access and service purpose. 
   While this projection structure hastens and reduces the cost associate with initially installing the motherboard in the chassis and subsequently removing the motherboard for service and replacement, it also increases the manufacturing cost of the computer since a configuration of the projection structure is complex. 
   A new mounting apparatus for circuit boards that overcomes the above-mentioned problems is desired. 
   SUMMARY OF THE INVENTION 
   An object of the present invention is to provide a mounting apparatus which can readily attach a circuit board onto a chassis. 
   In order to achieve the above object, a mounting apparatus in accordance with a preferred embodiment of the present invention comprises a chassis for mounting a motherboard, a fixing member, and a supporting member. The motherboard defines several first mounting holes. The chassis comprises a post arranged on a bottom wall thereof, and a plurality of standoffs received in the first mounting holes respectively. The fixing member is movably mounted to the post of the chassis. The fixing member comprises a first engaging portion protruding from a middle portion thereof. The supporting member is attached to the motherboard, and comprises a second engaging portion projecting from an end thereof. When the first engaging portion of the fixing member engages with the second engaging portion of the supporting member, the motherboard is in a lock state. When the first engaging portion of the fixing member disengages from the second engaging portion of the supporting member, the motherboard is in an unlock state. 
   Other objects, advantages and novel features of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings, in which: 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is an exploded, isometric view of a mounting apparatus in accordance with a preferred embodiment of the present invention, together with a motherboard; 
       FIG. 2  is an enlarged, cut-away view of a fixing member of the mounting apparatus of  FIG. 1 , but viewed from another aspect, and an enlarged view of a post of a chassis of the mounting apparatus of  FIG. 1 ; 
       FIG. 3  is an enlarged view of the fixing member of the mounting apparatus of  FIG. 1 , but viewed from another aspect; 
       FIG. 4  is a partial, assembled view of the fixing member and the chassis of the mounting apparatus of  FIG. 1 ; 
       FIG. 5  is an enlarged, assembled view of a supporting member of the mounting apparatus and the motherboard of  FIG. 1 ; 
       FIG. 6  is an assembled view of the mounting apparatus and the motherboard of  FIG. 1 , showing the motherboard in a lock state; 
       FIG. 7  is an enlarged view of a circle portion VII of  FIG. 6 ; 
       FIG. 8  is similar to  FIG. 6 , but showing the motherboard in an unlock state; and 
       FIG. 9  is an enlarged view of a circle portion IX of  FIG. 8 ; 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Reference will now be made to the drawings to describe the present invention in detail. 
     FIG. 1  shows a mounting apparatus in accordance with the preferred embodiment of the present invention, together with a circuit board such as a motherboard  70 . The mounting apparatus comprises a chassis  10 , a supporting member  50  and a fixing member  30 . 
   The motherboard  70  is mounted to the chassis  10 . The motherboard  70  has a generally planar, rectangular substrate body  72 . The substrate body  72  defines several first mounting holes  73  therethrough, and several through holes  71  near an end thereof. Each first mounting hole  73  is generally calabash-shaped. The first mounting hole  73  has a first narrow portion  76 , and a first broad portion  74 . 
   The chassis  10  has a bottom wall  11 . The bottom wall  11  has several upstanding standoffs  17  corresponding to the first mounting holes  73  of the motherboard  70 , respectively. Each standoff  17  includes a cylindrical base portion  175 , a generally conical upper end portion  171 , and an intermediate neck portion  173  extending between the base portion  175  and the end portion  171 . A diameter of the end portion  171  is smaller than that of the first broad portion  74  of the first mounting hole  73 , and is greater than that of the first narrow portion  76  of the first mounting hole  73 . A pair of screws  15  protrudes from the bottom wall  11  for retaining the supporting member  50 . Each screw  15  has a cap portion  152 , and a post portion  151 . A post  13  projects from the bottom wall  11  for mounting the fixing member  30 . Referring also to  FIG. 2 , the post  13  has a first planar portion  131  formed on an outer surface thereof, and a threaded hole  133  defined in a center of an upper portion thereof. 
   Referring to  FIGS. 1–4 , the fixing member  30  is mounted to the post  13  of the chassis  10 . The fixing member  30  has a main body  34 . A pair of resilient feet  31  extends from a bottom of the main body  34 . A pair of symmetrical pressing arms  33  extends from left and right sides of a lower portion of the main body  34  respectively. Each pressing arm  33  has a first slope  331  formed at an inner side thereof. An inclined guiding portion  37  is formed on an upper portion of the main body  34 . A first engaging portion  35  protrudes from a middle portion of the main body  34 . The first engaging portion  35  is connected angularly with the guiding portion  37 . A semi-circular bulge  351  protrudes outwardly from the first engaging portion  35 . A through hole  39  is defined in a center of the main body  34 , for receiving the post  13  of the chassis  10 . An annular protrusion  392  projects from a middle of the hole  39 . A diameter of an inner hole surrounded by the protrusion  392  is smaller than that of a screw cap (not labeled) of a screw  135 . A second planar portion  394  is formed on an inner surface of the protrusion  392 , corresponding to the first planar portion  131  of the post  13 . The second planar portion  394  of the fixing member  30  and first planar portion of the post  13  cooperatively prevent the fixing member  30  from rotating around the post  13  of the chassis  10 . 
   Referring to  FIGS. 1 ,  5 ,  7  and  9 , the supporting member  50  is partially mounted below the motherboard  10 . The supporting member  50  has a main portion  58 , and an extending portion  59  extending from an end of the main portion  58 . Four protruding portions  51  project from four corners of the main portion  58 , respectively. Each protruding portion  51  defines a threaded hole  511  corresponding to the hole  71  of the motherboard  70 . An annular projection  52  protrudes from a center of the main portion  58  for supporting the motherboard  70 . A pair of second mounting holes  53  is defined in the main portion  58  and located at opposite sides of the projection  52 . Each second mounting hole  53  is also generally calabash-shaped. The second mounting hole  53  has a second narrow portion  532 , and a second broad portion  534 . A diameter of the narrow portion  532  is smaller than that of the cap portion  152  of the screw  15 , and the diameter of the cap portion  152  of the screw  15  is smaller than that of the broad portion  534 . A cutout  54  is defined in a distal end of the extending portion  59 . A pair of bent portions  55  protrudes from right and left sides of the extending portion  59  surrounding the cutout  54 , respectively. Each bent portion  55  has a second slope  551  engaging with the first slope  331  of the fixing member  30 . A generally L-shaped second engaging portion  57  projects from a center of an end of the cutout  54 . A curve recess  572  is defined at an end of a top portion of the second engaging portion  57  for receiving the bulge  351  of the fixing member  30 . 
   Referring to  FIGS. 1 ,  2 ,  6 ,  7  and  9 , in assembly, the post  13  of the chassis  10  is received in the hole  39  of the fixing member  30 . The first planar portion  131  of the post  13  abuts against the second planar portion  394  of the fixing member  30 . The screw  135  is threadedly received in the threaded hole  133  of the post  13 , so that the fixing member  30  is movably but unrotatably mounted to the bottom wall  11  of the chassis  10 . The screws  512  are threadedly received in the corresponding threaded holes  511  of the supporting member  50  through the hole  71  of the motherboard  70 , the motherboard  70  is thus engaged with the supporting member  50 . The standoffs  17  of the chassis  10  are received in the corresponding first broad portions  74  of the first mounting holes  73  of the motherboard  70 . The screws  15  are received in the second broad portion  534  of the second mounting hole  53  of the supporting member  50 . The second engaging portion  57  of the supporting member  50  abuts against the guiding portion  37  of the fixing member  30  so as to form a first interaction mechanism. When the motherboard  70  is pressed, the second engaging portion  57  of the supporting member  50  slides downwardly along the guiding portion  37 . The supporting member  50  exerts force on the fixing member  30  to cause the feet  31  to deform elastically. The fixing member  30  applies opposite force on the supporting member  50  to cause the motherboard  70  and the supporting member  50  to move along the direction of an arrow “A”. When the recess  572  of the supporting member  50  abuts against the bulge  351  of the fixing member  30 , the standoffs  17  are received in the corresponding first narrow portions  76  of the motherboard  70 , and the screws  15  are received in the corresponding second narrow portions  532  of the supporting member  50  so as to form a third interaction mechanism. Simultaneously, each foot  31  of the fixing member  30  comes back its original position. Thus, the motherboard  70  together with the supporting member  50  is assembled to the chassis  10 . In this position, the motherboard  70  is defined in a lock state. 
   Referring to  FIGS. 1 ,  4 – 5 , and  7 – 9 , in removal of the motherboard  70  from the chassis  10 , the fixing member  30  is pressed to cause each foot  31  of the fixing member  30  to deform elastically. The first slope  331  of the fixing member  30  exerts force on the second slope  551  of the supporting member  50  so as to form a second interaction mechanism. The recess  572  of the supporting member  50  moves upwardly along the guiding portion  37  of the fixing member  30 . The motherboard  70  moves along the direction of an arrow “B”. The standoffs  17  move to the first broad portions  74  of the motherboard  70 , respectively. The screws  15  move to the second broad portions  534  of the supporting member  50 , respectively. Thus, the motherboard  70  together with the supporting member  50  is disengaged from the chassis  10 . In this position, the motherboard  70  is defined in an unlock state. 
   In the lock state, the fixing member  30  is engaged with the post  13  of the chassis  10 , so that the motherboard cannot move along the direction of the arrow “B”. Simultaneously, the diameter of the first narrow portion  76  of the first mounting hole  73  is smaller than that of the end portion  171  of the standoff  17 . The diameter of the second narrow portion  532  of the second mounting hole  53  is smaller than that of the cap portion  151  of the screw  15 . Therefore, the motherboard  70  together with the supporting member  50  is stably fixed in the lock state. 
   The feet  31  of the fixing member  30  can be replaced by other resilient members (not shown) attached to the post  13  of the chassis  10 . 
   While a preferred embodiment in accordance with the present invention have been shown and described, equivalent modifications and changes known to persons skilled in the art according to the spirit of the present invention are considered within the scope of the present invention as defined in the appended claims.