Mounting apparatus for circuit boards

[0001] 1. Field of the Invention

[0002] 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.

[0003] 2. Description of Related Art

[0004] 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 the assembled or the disassembled.

[0005] An 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.

[0006] 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.

[0007] A new mounting apparatus for circuit boards that overcomes the above-mentioned problems is desired.

[0008] An object of the present invention is to provide a mounting apparatus which can readily attach a circuit board onto a chassis.

[0009] 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, a supporting member, and a coil spring received in the fixing member. The motherboard defines several first mounting holes. The chassis comprises a pair of posts arranged on a bottom wall thereof, and a plurality of standoffs received in the first mounting holes respectively. The fixing member is horizontally movably mounted to the posts of the chassis. The fixing member comprises a first engaging portion and a first locating portion. The supporting member is attached to the motherboard, and comprises a second engaging portion and a second locating portion corresponding to the first engaging portion and the first locating portion respectively. When the circuit board together with the supporting member is mounted to the chassis, the first locating portion of the fixing member engages with the second locating portion of the supporting member; when the circuit board together with the supporting member is disassembled from the chassis, the first engaging portion of the fixing member exerts force on the second engaging portion of the supporting member.

[0010] 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:

[0017] Reference will now be made to the drawings to describe the present invention in detail.

[0018] 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 10. The mounting apparatus comprises a supporting member 20, a fixing member 40, a coil spring 60 and a chassis 80.

[0019] The motherboard 10 is mounted to the chassis 80. The motherboard 10 has a generally planar, rectangular substrate body 18. The substrate body 18 defines several first mounting holes 13 therethrough, and four through holes 12 near an end thereof. Each first mounting hole 13 is generally calabash-shaped. The first mounting hole 13 has a first narrow portion 16, and a first broad portion 14.

[0020] The chassis 80 has a bottom wall 81. The bottom wall 81 has several upstanding first standoffs 82 corresponding to the first mounting holes 13 of the motherboard 10 respectively. Each standoff 82 includes cylindrical base portion 825, a generally conically shaped upper end portion 821, and a neck portion 823 between the base portion 825 and the end portion 821. A diameter of the end portion 821 is smaller than that of the first broad portion 14 of the first mounting hole 13, and is greater than that of the first narrow portion 16 of the first mounting hole 13. A pair of fastener 84 protrudes from the bottom wall 81 for retaining the supporting member 20. Each fastener 84 has a cap portion 843, and a post portion 841. Two posts 86 project from the bottom wall 81 for mounting the fixing member 40. Each post 86 defines a threaded hole 860.

[0021] Referring also to FIGS. 2 and 3, the fixing member 40 is movably mounted to the posts 86 of the chassis 80. The fixing member 40 defines two grooves 46, 48, corresponding to the posts 86 of the chassis 80. The groove 46 is not in a line with the groove 48. The groove 48 has a stop wall 49. The breadths of the grooves 46, 48 are smaller than a diameter of a head of a screw 90, respectively, so that the fixing member 40 cannot disengage from the chassis 80 when the fixing member 40 is mounted to the chassis 80. A handle 50 extends upwardly from an end of the fixing member 40, adjacent to the groove 48. A guiding portion 52 protrudes from an inside of the handle 50. A first locating portion 54 projects from a side of the fixing member 40, adjacent to the guiding portion 52. The first locating portion 54 includes a locating slope 56. A triangular first engaging portion 42 extends from the side of the fixing member 40, adjacent to the groove 46. The first engaging portion 42 has a slope 44 formed inside thereof. There is a space between the first locating portion 54 and the first engaging position 42.

[0022] Referring to FIGS. 1 and 4, the supporting member 20 is partially mounted below the motherboard 10. The supporting member 20 has a main portion 21. Four protruding portions 22 projects from four corners of the main portion 21 respectively. Each protruding portion 22 defines a threaded hole 24 corresponding to the hole 12 of the motherboard 10. An annular projection 23 protrudes from a center of the main portion 21 for supporting the motherboard 10. A pair of second mounting holes 30 is defined in the main portion 21 and located at opposite sides of the projection 23. Each second mounting hole 30 is also generally calabash-shaped. The second mounting hole 30 has a second narrow portion 32, and a second broad portion 31. A diameter of the second narrow portion 32 is smaller than that of the cap portion 843 of the fastener 84, and the diameter of the cap portion 843 of the fastener 84 is smaller than that of the second broad portion 31. An L-shaped bend portion 26 protrudes from a distal end of the main portion 21. The bend portion 26 has a slopy second engaging portion 27 corresponding to the first engaging portion 42, and a second locating portion 29 corresponding to the first locating portion 54.

[0023] Referring to FIGS. 1–5, in assembly, the posts 86 of the chassis 80 are received in the grooves 46, 48 of the fixing member 40, respectively. The screws 90 are threadedly retained in the corresponding posts 86. The coil spring 60 is received in the groove 48 of the fixing member 40. One end of the coil spring 60 abuts against the stop wall 49 of the groove 48, and the other end of the coil spring 60 is fixed on the post 86. The fixing member 40 is thereby slidably mounted to the chassis 80. The screws 95 are threadedly received in the corresponding threaded holes 24 of the supporting member 20 through the holes 12 of the motherboard 10 accordingly the motherboard 10 is engaged with the supporting member 20. The standoffs 82 of the chassis 80 are received in the corresponding first broad portions 14 of the first mounting holes 13 of the motherboard 10. The fasteners 84 are received in the second broad portions 31 of the second mounting holes 30 of the supporting member 20. A side 28 of the bend portion 26 of the supporting member 20 exerts force on the guiding portion 52 of the fixing member 40 to cause the fixing member 40 to move in a first direction with the coil spring 60 being compressed. The motherboard 10 is pushed in a second direction perpendicular to the first direction, until the standoffs 82 are received in the corresponding first narrow portions 16 of the motherboard 10, and the fasteners 84 are received in the corresponding second narrow portions 32 of the supporting member 20. Thus, the motherboard 10 together with the supporting member 20 is assembled to the chassis 80. In this position, the motherboard 10 is defined in a first position. In the first position, the first locating portion 54 of the fixing member 40 abuts against the second locating portion 29 of the supporting member 20. The coil spring 60 decompresses. The bend portion 26 of the supporting member 20 disengages from the guiding portion 52 of the fixing member 40.

[0024] Referring also to FIG. 6, in removal of the motherboard 10 from the chassis 80, the handle 50 of the fixing member 40 is operated to cause fixing member 40 to move in the first direction with the coil spring 60 being compressed. The slope 44 of the first engaging portion 42 of the fixing member 40 exerts force on the second engaging portion 27, so that the motherboard 10 is moved in a third direction opposite to the second direction. The standoffs 82 move to the first broad portions 14 of the motherboard 10 respectively. The fasteners 84 move to the second broad portions 31 of the supporting member 20 respectively. Thus, the motherboard 10 together with the supporting member 20 is ready to be removed from the chassis 80. In this position, the motherboard 10 is defined in a second position.

[0025] In the first position, the first locating portion 54 of the fixing member 40 abuts against the second locating portion 29 of the supporting member 20, so that the motherboard 10 cannot move in the third direction. Simultaneously, the diameter of the first narrow portion 16 of the first mounting hole 13 is smaller than that of the end portion 821 of the standoff 82. 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 fastener 84. Therefore, the motherboard 10 together with the supporting member 20 is stably fixed in the first position.

[0026] 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.