Patent Publication Number: US-2002012218-A1

Title: Grounding device

Description:
BACKGROUND OF THE INVENTION  
       [0001] 1. Field of the Invention  
       [0002] The present invention relates to a grounding device, more particularly to a grounding device which is disposed between a housing of an electronic device and an electric component module removably mounted in the housing so as to drain static charges that accumulates on the electric component module.  
       [0003] 2. Description of the Related Art  
       [0004] Memory devices, such as disk drives, are generally mounted fixedly within a computer housing. In view of the demand to process huge amounts of data, removable memory devices have been developed to allow users to store data and programs in various memory devices.  
       [0005] With reference to FIGS. 1 and 2, an electric component module  2 , such as a memory device, is removably and slidably mounted in guideways  12  defined by upper and lower guide plates  11  of a housing  1 , which is formed from metal. To drain static charges on the module  2  and to facilitate sliding movement of the module  2 , a grounding device  3  is disposed between the housing  1  and the module  2 . The grounding device  3  includes left and right sliding bodies  31  and a plurality of electrically conductive studs  32 . Each of the conductive studs  32  has a tail portion  321  and a head portion  322 . The sliding bodies  31  are mounted outboard to the module  2  by means of the conductive studs  32  which are extended through the sliding bodies  31 , with the tail portions  321  thereof inserted into mounting holes  21  formed in lateral walls of the module  2 , while the head portions  322  project beyond the sliding bodies  31  to contact inner side walls of the housing  1 , thereby establishing electrical contact between the module  2  and the housing  1  so as to drain the static charges on the module  2  via the housing  1 .  
       [0006] However, the conventional grounding device  3  is defective in terms of assembly. As the sliding bodies  31  are mounted in the lateral walls of the module  2  by means of the tail portions  321  of the conductive studs  32  without any securing or locking means, the sliding bodies  3  may easily detach from the module  2  during outward pulling of the module  2  from the housing  1 . Moreover, as grounding is achieved mainly via the head portions  322  of the conductive studs  32  which contact the inner side walls of the housing  1 , the grounding effect is not satisfactory.  
       SUMMARY OF THE INVENTION  
       [0007] Therefore, the main object of the present invention is to provide a grounding device which is disposed between a housing of an electronic device and an electric component module removably mounted in the housing so as to drain static charges that accumulate on the electric component module.  
       [0008] Accordingly, a grounding device of this invention is adapted for draining static charges that accumulate on an electric component module in an electrically conductive housing. The housing includes left and right side walls spaced apart from each other in a longitudinal direction, and at least two guideways disposed on and inboard to the left and right side walls respectively and extending in a first direction transverse to the longitudinal direction. The electric component module is accommodated in the housing, and includes a front panel with left and right lateral edges opposite to each other in the longitudinal direction, and electrically conductive left and right lateral walls respectively extending rearwardly from the left and right lateral edges in the first direction and facing toward the left and right side walls. Each of the guideways includes upper and lower guiding plates which are spaced apart from each other in a second direction transverse to both the first direction and the longitudinal direction. The upper and lower guiding plates of the guideways are formed by punching the left and right side walls. The grounding device includes electrically insulative left and right sliding bodies, and an electrically conductive strip. The left and right sliding bodies are formed from a flexible material and are adapted to be detachably secured to the left and right lateral walls, respectively. Each of the left and right sliding bodies includes upper and lower sliding wall surfaces, inner and outer abutment walls, and an urging tongue portion. The upper and lower sliding wall surfaces are opposite to each other in the second direction and are adapted to abut against the upper and lower guiding plates of a respective one of the guideways. The inner and outer abutment walls are spaced apart from each other in the longitudinal direction. The inner abutment wall has first and second inner abutment surfaces opposite to each other in the longitudinal direction. The first inner abutment surface is adapted to abut against a respective one of the left and right lateral walls. The outer abutment wall has first and second outer abutment surfaces opposite to each other in the longitudinal direction. The first outer abutment surface faces toward the second inner abutment surface. The second outer abutment surface is adapted to face toward the respective one of the left and right side walls. The outer abutment wall includes an inner peripheral portion which defines a mounting slot extending from the second outer abutment surface in the longitudinal direction to communicate with the second inner abutment surface. The urging tongue portion has proximate and distal ends. The proximate end is integrally formed with the second inner abutment surface. The distal end extends in the first direction and toward a respective one of the left and right lateral walls so as to be disposed beyond the first inner abutment surface in the longitudinal direction such that the distal end is forced to be flush with the first inner abutment surface against biasing action of the urging tongue portion when the first inner abutment surface abuts against the respective one of the left and right lateral walls. The distal end has an urging abutment surface adapted to abut against the respective one of the left and right lateral walls. The conductive strip has a contact end portion, a middle portion, and a securing end portion. The contact end portion is anchored on the urging abutment surface so as to be clamped between a respective one of the left and right lateral walls and the urging abutment surface when the urging tongue portion is flush with the first inner abutment surface. The middle portion extends from the contact end portion into the mounting slot, and terminates at a contact juncture. The securing end portion extends from the contact juncture and is disposed to anchor on the inner peripheral portion such that the contact juncture is forced away from the respective one of the left and right lateral walls by the securing end portion and the middle portion, and protrudes in the longitudinal direction and beyond the second outer abutment surface so as to abut against a respective one of the left and right side walls, thereby establishing electrical contact between the respective one of the left and right lateral walls and the respective one of the left and right side walls. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0009] Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiment with reference to the accompanying drawings, of which:  
     [0010]FIG. 1 is an exploded perspective view of a conventional grounding device adapted to be disposed between an electric component module and a housing;  
     [0011]FIG. 2 is a fragmentary partly sectional top view showing the conventional grounding device mounted between the module and the housing;  
     [0012]FIG. 3 is a perspective view illustrating how the preferred embodiment of a grounding device according to the present invention is mounted on an electric component module within a housing;  
     [0013]FIG. 4 is an exploded perspective view of the preferred embodiment in relation to the electric component module and the housing;  
     [0014]FIG. 5 is an exploded perspective view of the preferred embodiment; and  
     [0015]FIG. 6 is a fragmentary partly sectional top view illustrating how the preferred embodiment is mounted between the electric component module and the housing. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
     [0016] With reference to FIGS.  3  to  6 , the preferred embodiment of a grounding device  4  according to the present invention is shown to be adapted for draining static charges that accumulate on an electric component module  5 , via an electrically conductive housing  6  accommodated within a main body frame of an electronic device, such as a computer (not shown). The housing  6  is formed from metal, and includes left and right side walls  60  spaced apart from each other in a longitudinal direction, and at least two guideways  62  disposed on and inboard to the left and right side walls  60 , respectively, and extending in a first direction transverse to the longitudinal direction. Each of the guideways  62  includes upper and lower guiding plates  61  which are spaced apart from each other in a second direction transverse to both the first direction and the longitudinal direction. The upper and lower guiding plates  61  are formed by punching the left and right side walls  60  inwardly. The electric component module  5  is removably accommodated in the housing  6 , and includes a front panel  50  with left and right lateral edges opposite to each other in the longitudinal direction, and electrically conductive left and right lateral walls  52  respectively extending rearwardly from the left and right lateral edges in the first direction and facing toward the left and right side walls  60 . Each of the left and right lateral walls  52  is formed with two mounting holes  51 .  
     [0017] The grounding device  4  is shown to include electrically insulative left and right sliding bodies  41 , and an electrically conductive strip  42 . In this embodiment, the grounding device  4  includes two conductive strips  42 .  
     [0018] The left and right sliding bodies  41  are formed from a flexible material and are adapted to be detachably secured to the left and right lateral walls  52 , respectively. Each of the left and right sliding bodies  41  is an elongated block having front and rear end portions  411 ,  412  opposite to each other in the first transverse direction. The front end portion  411  is adapted to extend forwardly of the front panel  50 , and includes a recessed press portion  416  adapted to facilitate pulling of the electric component module  5  from the housing  6 . Each of the left and right sliding bodies  41  includes upper and lower sliding wall surfaces  410 , inner and outer abutment walls  43 ,  44 , and a first urging tongue portion  413 .  
     [0019] The upper and lower sliding wall surfaces  410  are opposite to each other in the second direction and are adapted to abut against the upper and lower guiding plates  61  of a respective one of the guideways  62 .  
     [0020] The inner and outer abutment walls  43 ,  44  are spaced apart from each other in the longitudinal direction. The inner abutment wall  43  has first and second inner abutment surfaces opposite to each other in the longitudinal direction. The first inner abutment surface is adapted to abut against a respective one of the left and right lateral walls  52 . The outer abutment wall  44  has first and second outer abutment surfaces opposite to each other in the longitudinal direction. The first outer abutment surface faces toward the second inner abutment surface. The second outer abutment surface is adapted to face toward the respective one of the left and right side walls  60 . The outer abutment wall  44  includes an inner peripheral portion which defines a mounting slot  415  that extends from the second outer abutment surface in the longitudinal direction to communicate with the second inner abutment surface. The second inner abutment surface and the first outer abutment surface cooperatively confine an accommodation space therebetween.  
     [0021] The first urging tongue portion  413  is disposed proximate to the front end portion  411 , and has a proximate end integrally formed with the second inner abutment surface, and a distal end extending in the first direction and toward a respective one of the left and right lateral walls  52  so as to be disposed beyond the first inner abutment surface in the longitudinal direction. The distal end has an urging abutment surface  4131  adapted to abut against the respective one of the left and right lateral walls  52 . When a respective one of the left and right sliding bodies  41  is mounted outboard to a respective one of the left and right lateral walls  52 , the first inner abutment surface abuts against the respective one of the left and right lateral walls  52 , and the distal end is forced to be flush with the first inner abutment surface against biasing action of the first urging tongue portion  413 . In addition, the distal end is disposed to extend toward the front end portion  411 , and has an inner lateral surface which is opposite to the urging abutment surface  4131  in the longitudinal direction and which is communicated with the accommodation space. The first urging tongue portion  413  is molded from the inner abutment wall  43  such that the distal end is depressible to permit the inner lateral surface to extend into the accommodation space. The distal end further includes a first anchored stud  414 . The first anchored stud  414  is disposed to extend uprightly from the urging abutment surface  4131  and is adapted to be received in the mounting hole  51  in the respective one of the left and right lateral walls  52 . In this embodiment, each of the left and right sliding bodies  41  further includes a second urging tongue portion  413  that is proximate to the rear end portion  412  thereof, and that has a distal end provided with a second anchored stud  414  adapted to be received in the respective one of the left and right lateral walls  52 . The first and second urging tongue portions  413  are slightly inclined toward each other such that the distance therebetween is shorter than that between the two mounting holes  51 . As such, the left and right sliding bodies  41  can be better secured to the left and right lateral walls  52 .  
     [0022] The conductive strip  42  is formed from metal, and has a contact end portion  421 , a middle portion  420 , and a securing end portion  423 . The contact end portion  421  is anchored on the urging abutment surface  4131  by means of a hooking hole formed therein to engage the first anchored stud  414 , and is clamped between a respective one of the left and right lateral walls  52  and the urging abutment surface  4131  when the first urging tongue portion  413  is flush with the first inner abutment surface. Certainly, the contact end portion  421  may be anchored on any other suitable part of the respective sliding body  41 . The middle portion  420  extends from the contact end portion  421  into the mounting slot  415  and terminates at a contact juncture  422 . The securing end portion  423  extends from the contact juncture  422 , and is disposed to anchor on the inner peripheral portion. The conductive strip  42  is configured so that the contact juncture  422  is forced away from the respective one of the left and right lateral walls  52  by both the securing end portion  423  and the middle portion  420 , and protrudes in the longitudinal direction and beyond the second outer abutment surface so as to abut against a respective one of the left and right side walls  60 . As such, electrical contact is established between the respective one of the left and right lateral walls  52  and the respective one of the left and right side walls  60  to permit draining of static charges on the electric component module  5  via the housing  6 .  
     [0023] The grounding device  4  further includes a reinforcing member  45  disposed to extend in the longitudinal direction to interconnect the second inner abutment surface and the first outer abutment surface, and to be integrally formed with the inner peripheral portion to thereby permit the proximate end of the first urging tongue portion  413  to rest on the inner peripheral portion.  
     [0024] Furthermore, the first inner abutment surface includes a passage disposed proximate to the proximate end and distal to the distal end of the first urging tongue portion  413 . The passage extends from the first inner abutment surface to the second inner abutment surface so as to communicate with the mounting slot  415 , thereby permitting the middle portion  420  of the conductive strip  42  to pass therethrough. The inner abutment wall  43  includes a guiding block  46  disposed to extend from the second inner abutment surface toward the mounting slot  415  such that the middle portion  420  passes through the passage and is guided by the guiding block  46  to be directed toward the second inner abutment surface, thereby forcing the contact juncture  422  to protrude beyond the second outer abutment surface between the guiding block  46  and the securing end portion  423 .  
     [0025] In use, the sliding bodies  41  together with the conductive strips  42  are respectively mounted outboard to the left and right lateral walls  52  of the electric component module  5 , and the electric component module  5  together with the grounding device  4  is inserted into the housing  6  such that the contact junctures  422  respectively abut against the left and right side walls  60  of the housing  6 . Static charges that accumulate on the electric component module  5  can be drained via the grounding device  4  and the housing  6  at this time.  
     [0026] While the present invention has been described in connection with what is considered the most practical and preferred embodiment, it is understood that this invention is not limited to the disclosed embodiment but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements.