Abstract:
A disk drive unit includes a first cover having a first part of magnet component and a head stack assembly mounted on the first cover; and a second cover assembled with the first cover, which having a second part of magnet component, a spindle motor and at least one disks. The invention also discloses a ramp tool used for assembling the disk drive which has its disk and HSA assembled in two different halves, which includes a tool body; and a holding means extending from the tool body to hold a lift tab of a head stack assembly in a loading status. The invention also disclose a method of assembling such as disk drive unit.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates to disk drive units, a tool for assembling such disk drive units and an assembly method of such disk drive unit using the tool.  
       BACKGROUND OF THE INVENTION  
       [0002]     Referring to  FIG. 1 , a traditional disk drive  20  has a bottom part and a top cover  29  which are combined with each other. The bottom part comprises a head stack assembly (HSA)  17  with a slider (not shown), a disk  11 , and a ramp  15  mounted on a bottom cover  19 . The disk  11  is mounted on a spindle motor  31  which causes the disk  11  to spin, and a voice-coil motor  13  is provided for controlling the motion of the HSA  17  and thus controlling the slider thereon to move from track to track across the surface of the disk  11  to read data from or write data to the disk  11 . The ramp  15  transitions the slider off-of and back-onto a flying area above the surface of the rotating disk  11 , which typically interacts with a lift tab at an end of the HSA  17 .  
         [0003]     However, the rework of the HSA  17  of the traditional disk drive  20 , especially the slider, is not convenient because it must remove the HSA  17  from the bottom cover  19  before rework. In order to simplify the rework of the HSA  17 , it attempts to mount the HSA  17  on the top cover  29 . In this way, it is not required to remove the HSA  17  from the top cover  29  when reworking the HSA  17 , especially the slider, but only need to separate the top cover  29  with the bottom part. But if the HSA  17  is mounted on the top cover  29 , it is difficult to load the lift tab of the HSA  17  on the ramp  15  to get an initial status when assembling the top cover  29  with the bottom part because there exists a free angle between the suspension at a free status and a loading status, which results in a difference therebetween at a horizontal direction.  
         [0004]     It is therefore desirable to provide a disk drive unit with its disk and HSA assembled in two different halves, a ramp tool for assembling such disk drive units and an assembly method of disk drive unit using the ramp tool to solve the above-mentioned problems.  
       SUMMARY OF THE INVENTION  
       [0005]     A main feature of the present invention is to provide a disk drive unit which has its disk and HSA assembled in two different halves.  
         [0006]     Another feature of the present invention is to provide a ramp tool for easily assembling a disk drive unit which has its disk and HSA assembled in two different halves.  
         [0007]     A further feature of the present invention is to provide a method of assembling such an disk drive unit using the ramp tool.  
         [0008]     To achieve the features of the invention, a disk drive unit comprises a first cover having a first part of magnet component and a HSA mounted on the first cover; a second cover assembled with the first cover, which having a second part of magnet component, a spindle motor and at least one disks. In the present invention, a ramp is formed on the second cover, and a ramp tool opening is formed on the first cover corresponding to the ramp for being extended through by a ramp tool. The HSA comprises a suspension with a lift tap formed at an end thereof, the lift tab is engaged with the ramp by being transferred from the ramp tool to the ramp.  
         [0009]     A ramp tool used for assembling disk drive unit which has its disk and HSA assembled in two different halves, which comprises a tool body; and a holding means extending from the tool body for holding a lift tab of the HSA in a loading status. As an embodiment, the ramp tool further comprises a handle connected with the tool body for operating the ramp tool.  
         [0010]     As an embodiment of the invention, the holding means vertically extends from the side of the tool body. The handle has a larger contour than that of the tool body.  
         [0011]     An assembly method of a disk drive unit comprises the steps of: assembling a disk and a ramp on a first half of the disk drive unit; and assembling a head stack assembly on a second half of the disk drive unit with a ramp tool opening formed thereon corresponding to the ramp; forming a ramp tool and inserting it to extend through the ramp tool opening to hold a lift tab of head stack assembly in a loading status; assembling the first and second halves together to superpose the lift tab, the ramp tool and the ramp together; moving the ramp tool to transfer the lift tab of head stack assembly from the ramp tool to the ramp on the first half of the disk drive unit.  
         [0012]     In the present invention, forming the ramp tool comprises a step of forming a holding means thereon to hold the lift tab; a step of forming a tool body which can rotate in the ramp tool opening; and a step of forming a handle to operate the ramp tool. In addition, the method further comprises a step of removing the ramp tool from the second half of the disk drive unit, and a step of sealing the ramp tool opening by adhesive tape or plugger.  
         [0013]     Because the ramp tool of the present invention is used to hold the lift tab of the HSA in a loading status before the first and second halves of the disk drive unit are combined together, so it deletes the influence of the free angle existing between the suspension of the HSA in a free status and a loading status. In addition, because the ramp tool can be rotated in the ramp tool opening, so it can adjust the position of the lift tab loaded thereon corresponding to the ramp, and is easily removed from the position between the lift tab and the ramp when the lift tab, the ramp tool and the ramp are superposed together, and thus transfers the lift tab onto the ramp. Most importantly, because the HSA is mounted on a half of the disk drive unit which is different with the half of the disk drive unit with the disk mounted, so the HSA, especially the slider, can be rework in a disk drive level, that is, it is not required to remove the HSA from the second half of the disk drive, and only need to separate the first and second halves of the disk drive unit with each other. Finally, the ramp tool of the present invention can be easily removed from the second half of the disk drive unit after transferring the lift tap of the suspension to the ramp, so that it won&#39;t affect normal operation of the disk drive unit after assembly.  
         [0014]     Other objects, advantages and novel features of the invention will become more apparent from the following detailed description of a preferred embodiment thereof when taken in conjunction with the accompanying drawings, wherein: 
     
    
     DESCRIPTION OF THE DRAWINGS  
       [0015]      FIG. 1  is an exploded, perspective view of a traditional disk drive unit;  
         [0016]      FIG. 2  is an exploded, perspective view of a disk drive unit according to an embodiment of the present invention;  
         [0017]      FIG. 3  is an perspective view of a HSA of the disk drive unit of  FIG. 2 ;  
         [0018]      FIG. 4  is an perspective view to show a top cover of the disk drive unit of  FIG. 2  and a ramp tool of the present invention, and an assembly relationship therebetweeen;  
         [0019]      FIG. 5  is a partial, schematic view showing a suspension of the HSA of  FIG. 3  held in a loading status by the ramp tool;  
         [0020]      FIG. 6  is a partial, schematic view showing a suspension of the HSA of  FIG. 3  in a free status;  
         [0021]      FIG. 7  is a perspective view showing a suspension of the HSA of  FIG. 3  held in a loading status by the ramp tool;  
         [0022]      FIG. 8  is an enlarged, perspective view depicting a lift tap of the suspension being transferred from the ramp tool to the ramp;  
         [0023]      FIG. 9  is a perspective view to show a status that the lift tap of the suspension being transferred to the ramp, which omitting the top cover and a top magnet component herefrom; and  
         [0024]      FIG. 10  is a perspective view to show a working status of the disk drive unit of  FIG. 2 , which omitting the top cover and a top magnet component herefrom. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0025]     Referring now to the drawings in detail,  FIG. 2  shows a disk drive unit  35  according to an embodiment of the present invention. The disk drive unit  35  comprises a top part  3  and a bottom part  5 . The top part  3  comprises a top cover  129 , a top magnet component  52  and a HSA  117  mounted on the top cover  129 . As an embodiment, the HSA  117  is mounted on the top cover  129  by a bearing  38  so that the HSA  117  can rotate about it. The bottom part  5  comprises a bottom cover  119 , a bottom magnet component  51  and a spindle motor  131  mounted on the bottom cover  119 . A disk  111  is mounted on and rotated by the spindle motor  131 . The top cover  129  and the bottom cover  119  are combined with each other by securing means (not shown). In the invention, a ramp  115  is formed on one side of the bottom cover  119 , which is adjacent to the disk  111 .  
         [0026]     Referring to  FIG. 3 , the HSA  117  comprises a drive arm  171 , a suspension  172  connected with the drive arm  171 , and a slider  174  mounted on the suspension  172  (the suspension  172  with the slider  174  is called “HGA”). A lift tap  175  is formed at a far distal end of the suspension  172 , which is used to engage with the ramp  115 . As shown in  FIGS. 2 and 6 , when the suspension  172  is at a free status, which is biased in a direction deviating from the top cover  129 . When the suspension  172  is at a loading status, the lift tap  175  is engaged with the ramp  115 , and the suspension  172  is parallel to the drive arm  171 , as shown in  FIG. 5  (the numeral  73  can be understood as the ramp  115 ). So, it is easy to see there exists a free angle between the suspension  172  at a free status and a loading status, which causes a difference b at a horizontal direction between the lift tab  175  at a free status and a loading status. So, when combining the top part  3  with the bottom part  5 , it will very difficult to load the lift tab  175  on the ramp  15  to get an initial position because in this time the position of the lift tab  175  is not corresponding to the position of the ramp  115 .  
         [0027]     To load the lift tab  175  on the ramp  15  when combining the top part  3  with the bottom part  5 , the invention provides a ramp tool with a special structure. Accordingly, the disk drive unit  35  can be assembled as follows: forming the top cover  129  with a ramp tool opening corresponding to the ramp  115 ; assembling a HSA  117  and other essential parts on the top cover  129  to form a top part  3 ; and assembling the disk  111 , the ramp  115  and other essential parts on the bottom cover  119  to form a bottom part  5 ; inserting the ramp tool to extend through the ramp tool opening to hold a lift tab of HSA  117  at a loading status; assembling the top part  3  with the bottom part  5  to superpose the lift tab, the ramp tool and the ramp  115  together; and moving the ramp tool to transfer the lift tab of HSA  117  from the ramp tool to the ramp  115  on the bottom cover  119 .  
         [0028]     According to a first embodiment of the invention, referring to  FIG. 4 , the ramp tool  7  comprises a tool body  71  and a holding plate  73  extending from the side of the tool body  71 . The tool body  71  is cylinder-shaped and the holding plate is bar-shaped which is perpendicular to the axis of the tool body  71 . In addition, the ramp tool  7  may further comprise a handle  75  connected with the tool body  71 , which is used for operating the ramp tool  7 . In an embodiment, the handle  75  is also cylinder-shaped, which has a larger diameter than that of the tool body  71 . In the present invention, see  FIGS. 2 and 4 , a ramp tool opening  32  is formed on a top plate  39  of the top cover  3  corresponding to the ramp  115  for being extended through by the ramp tool  7 . The ramp tool opening  32  is constituted by an arc opening  321  with an obtuse angle and a bar opening  322 . In the embodiment, the contour of the bar opening  322  is equal to or larger than that of the holding plate. The diameter of the arc opening  321  is equal to or larger than that of the tool body  71 , but less than that of the handle  75 . The tool body  71  has a length larger than the thickness of the top plate  39  of the top cover  129 , and the distance between the holding plate  73  and the handle  75  are also larger than the thickness of the top plate  39  of the top cover  129 , so that the holding plate  73  can extend through the ramp tool opening  32  and hold the lift tab  175  of the HSA  117 .  
         [0029]     In the present invention, referring to  FIG. 4 , the hard disk drive  35  are assembled as follows: firstly, the ramp tool  7  is inserted into the ramp tool opening  32 , because the diameter of the arc opening  321  is less than that of the handle  75 , so the handle  75  is left outside of the top cover  129 . Thus, the ramp tool  7  can be rotated by the handle  75  with the axis of the tool body  71  as rotation axis even when the top part  3  and the bottom part  5  are combined together due to the shape of the arc opening  321  and the tool body  71 . Then, referring to  FIG. 7 , the ramp tool  7  is rotated and the holding plate  73  thereof hooks in and exerts a force to the lift tap  175  so as to hold the lift tab  175  at a loading status, as shown in  FIG. 5 . At the time, the lift tap  175  exerts a counterforce to the holding plate  73  so as to hold the ramp tool  7  on the top cover  129 .  
         [0030]     After that, the top part  3  is combined with the bottom part  5  so that the top magnet component  52  and the bottom magnet component  51  are faced with each other and constitute a servo control system (such as a VCM) to move the HSA  117  around the bearing  38 . Because the ramp tool opening  32  is designed corresponding to the ramp  115 , and the lift tap  175  is held at a loading status, thus the holding plate  73 , the lift tab  175  and the ramp  115  are superposed together, and the holding plate  73  is interposed between the lift tab  175  and the ramp  115 , as shown in  FIG. 8 . When the top part  3  and the bottom part  5  are combined, the lift tab  175  is easily transferred from the holding plate  73  to the ramp  115  by rotating the ramp tool  7 , and engaged with the ramp  115 , as shown in  FIG. 9 . When at a working status, the lift tab  175  of the suspension  172  is moved down the ramp  115  by the server control system such that an air bearing is developed between the slider  174  and the disk  111 . Then, the slider  174  moves free of the ramp  115  and flies above on the disk  2  to read data from or write data to the magnetic disk  2 , as shown in  FIG. 10 . When the work is stopped, the lift tab  175  is moved onto the ramp  15  such that the slider  174  is moved away from the disk  111 .  
         [0031]     After the lift tab  175  engages with the ramp  115 , the ramp tool  7  can be removed from the top cover  129  through the ramp tool opening  32  by rotating the ramp tool  7  to a predetermined position. To keep a good appearance of the disk drive unit  35  and prevent other objects from entering the chamber formed by the top part  3  and the bottom part  5 , the ramp tool opening  32  can be sealed by adhesive tape or plugger.  
         [0032]     In the present invention, the ramp tool  7  can be made of a single material, such as metal or plastic, or several materials, for example, the different portions of the ramp tool  7  are made of different materials. The materials have enough rigidity so as to reliably hold the lift tab  175  at a loading status, such as stainless steel. As an embodiment, the ramp tool  7  can be integrally formed or formed by assembled the different portions thereof. In addition, the holding plate  73  has a small thickness and accordingly the distance between the lift tab  175  and the ramp  115  is short when the lift tab  175 , the holding plate  73  and the ramp  115  are superposed together. Thus, the lift tab  175  can be transferred onto the ramp  115  more smoothly and more precisely.  
         [0033]     In the present invention, the handle  75  is not limited to the cylinder-shaped structure, any structure having a contour larger than that of the arc opening  321  can be used. Similarly, the holding plate  73  and the tool body  71  is also not limited to the above-mentioned structure, any structures performing a same function can be used.  
         [0034]     In the present invention, the ramp tool is used to hold the lift tab of the suspension in a loading status before the top part and the bottom part are combined together, so it deletes the influence of the free angle existing between the suspension in a free status and a loading status. In addition, because the ramp tool can be rotated, so it can adjust the position of the lift tab corresponding to the ramp, and is easily removed from the position between the lift tab and the ramp when the lift tab, the ramp tool and the ramp are superposed together, and thus transfers the lift tab onto the ramp. Most importantly, because the HSA is mounted on the top cover, the HSA, especially the slider, can be rework in a disk drive level, that is, it is not required to remove the HSA from the top cover, and only need to separate the top part with the bottom part. Finally, the ramp tool of the present invention can be easily removed from the top cover after transferring the lift tap of the suspension to the ramp, so that it won&#39;t affect normal operation of the disk drive unit after assembly.