Patent Abstract:
A loading apparatus for a disc drive which has a traverse module for loading a disc thereon and reading from or recording to the disc including a gear for transmitting a motive force of a driving motor and a slider for lifting the traverse module up to load the disc. The slider forms a toothed portion engageable with the gear. The toothed portion includes a first rack segment and a second rack segment. The first rack segment is flexibly deformable so as to overcome a conflict of alignment of gear teeth of the gear and the first rack segment when such conflict occurs.

Full Description:
FIELD OF THE INVENTION  
       [0001]     The present invention generally relates to a loading apparatus for a disc drive and, more particularly, to a loading apparatus for a disc drive with increased stability and reduced vibration during a loading procedure.  
       DESCRIPTION OF RELATED ART  
       [0002]     As one of the most important parts of a disc drive, a loading apparatus is used to perform the loading and unloading of discs. A typical loading apparatus  900 , referring to  FIG. 7 , includes a frame  99 , a motor  98  as a power supply, a pulley-gear wheel  97 , a duplicate gear  96 , and a slider  95 . The pulley-gear wheel  97 , the duplicate gear  96 , and the slider  95  are sequentially engaged with the motor  98  to transmit mechanical power and reduce rotational speed output by the motor  98 .  
         [0003]     A first pulley  982  is arranged on a shaft  980  of the motor  98 , and engages with a second pulley  972  of the pulley-gear wheel  97  via a belt  984 . A first gear (not shown) of the pulley-gear wheel  97  is engaged with a second gear  962 , while a third gear  964  of the duplicate gear  96  is engageable with both a rack  952  of the slider  95  and a rack of a tray (not shown). A guiding pin  954  is upwardly formed on the slider  95 . The guiding pin  954  is engageable with a guiding slot (not shown) defined in a back of the tray. When a mechanical force is transmitted to the duplicate gear  96  during a loading procedure, the tray moves towards the frame  99 , and the slider  95  moves along a direction of the rack  952  due to the engagement of the guiding slot and the guiding pin  954 . As a result, the rack  952  gradually engages with the third gear  964  of the duplicate gear  96 . However, during engagement of the rack  952  and the third gear  964 , the teeth thereof may not mesh properly and destructive grinding can occur, due to inaccurate alignment of, or imbalance of the engaging parts.  
         [0004]     Accordingly, a need exists for a loading apparatus in the industry to address the aforementioned deficiencies and inadequacies.  
       SUMMARY OF INVENTION  
       [0005]     A loading apparatus for a disc drive which has a traverse module for loading a disc thereon and reading from or recording to the disc including a gear for transmitting a motive force of a driving motor and a slider for lifting the traverse module up to load the disc. The slider forms a toothed portion engageable with the gear. The toothed portion includes a first rack segment and a second rack segment. The first rack segment is flexibly deformable to overcome a conflict of alignment of gear teeth of the gear and the first rack segment when such conflict occurs  
         [0006]     Other systems, methods, features, and advantages of the present loading apparatus will be or become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional systems, methods, features, and advantages be included within this description, be within the scope of the present apparatus, and be protected by the accompanying claims. 
     
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0007]     Many aspects of the present loading apparatus can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present device. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.  
         [0008]      FIG. 1  is a partially exploded, isometric view of a loading apparatus in accordance with an exemplary embodiment thereof, the loading device including a tray, a transmission system, and a loading system;  
         [0009]      FIG. 2  is an enlarged, isometric view of the tray of  FIG. 1 , viewed from an inverted aspect;  
         [0010]      FIG. 3  is an enlarged, isometric view of the transmission system and the loading system of  FIG. 1 , the transmission system including a cam slider;  
         [0011]      FIG. 4  is an isometric view of the cam slider of  FIG. 3 ;  
         [0012]      FIG. 5  is similar to  FIG. 3 , but viewed from another aspect;  
         [0013]      FIG. 6  is an assembled, isometric view of the loading apparatus, viewed from an inverted aspect; and  
         [0014]      FIG. 7  is an isometric view of a conventional loading apparatus. 
     
    
     DETAILED DESCRIPTION  
       [0015]     Reference will now be made to the drawings to describe the preferred embodiments of the present loading apparatus, in detail.  
         [0016]     Referring to  FIG. 1 , a loading apparatus  999 , which is used to load and unload a disc for a disc drive (not shown), is illustrated to set up an exemplary embodiment. The loading apparatus  999  includes a tray  1 , a frame  2 , a transmission system  3 , and a loading system  4 . The tray  1  is slidably mounted to the frame  2 , and is movable into or out from the frame  2  to convey a disc (not shown). The frame  2  is substantially rectangular, and defines a rectangular opening  20  in a center thereof. The transmission system  3  and the loading system  4  are mounted on a front beam  22  of the frame  2 . The transmission system  3  and the loading system  4  are engageable with each other to perform transmission of mechanical energy.  
         [0017]     Referring to  FIG. 2 , a rack rail  12  engageable with the transmission system  3  is formed at a lateral side of a bottom of the tray  1 , while a guiding groove  14  engageable with the loading system  4  is defined at an opposite lateral side. The rack rail  12  substantially extends along a longitudinal direction of the tray  1 . The guiding groove  14  includes a transverse portion  142  extending along a transverse direction of the tray  1 , an inclined portion  144 , and a longitudinal portion  146  extending along the longitudinal direction. The inclined portion  144  interconnects the transverse portion  142  and the longitudinal portion  146 .  
         [0018]     Referring also to  FIG. 3 , the transmission system  3  includes a driving motor  30  and four transmission units  32 ,  34 ,  36 ,  38  engaged with the driving motor  30 . The four transmission units  32 , 34 , 36 , 38  are sequentially engaged with each other. As a rotational speed output from the driving motor  30  is much higher than a speed needed during the loading procedure, the four transmission units  32 ,  34 ,  36 ,  38  perform as speed reduction transmission units.  
         [0019]     The first transmission unit  32  is a pulley train, and includes a first pulley  320  secured on a spindle  300  of the driving motor  30 , a belt  322 , and a second pulley  324  engaged with the first pulley via the belt  322 . The first transmission unit  32  contributes to the reduction of the rotational output speed of the transmission system  3 , and the motive force is transmitted from the driving motor  30  to the second pulley  324 .  
         [0020]     The second transmission unit  34  is a gear train, and includes a first gear  342  meshing with a second gear  344 . The first gear  342  is axially, integrally formed with the second pulley  324  of the first transmission unit  32  to form a first duplicate wheel  60  (referring to  FIG. 1 ). The rotational speed of transmission system  3  is further reduced by the second transmission unit  34 , and the motive force is transmitted from the first duplicate wheel  60  to the second gear  344 .  
         [0021]     The third transmission unit  36  is a gear train, and includes a third gear  362  meshing with a fourth gear  364 . The third gear  362  is axially, integrally formed with the second gear  344  of the second transmission unit  34  to form a second duplicate wheel  80  (referring to  FIG. 1 ). The rotational speed of transmission system  3  is further reduced by the third transmission unit  36 , and the motive force is transmitted from the second duplicate wheel  80  to the fourth gear  364 .  
         [0022]     The fourth transmission unit  38  is a gear train, and includes a fifth gear  382  meshing with a sixth gear  384 . The fifth gear  382  is axially, integrally formed with the fourth gear  364  of the third transmission unit  36  to form a third duplicate wheel  100  (referring to  FIG. 1 ). The rotational speed of transmission system  3  is further reduced by the fourth transmission unit  38 , and the motive force is transmitted from the third duplicate wheel  100  to the sixth gear  364 . The sixth gear  384  engages with the rack rail  12  of the tray  1 .  
         [0023]     Referring also to  FIG. 4  and  FIG. 5 , the loading system  4  includes a cam slider  42  connected with a loading bracket  44 . The cam slider  42  is engageable with the fifth gear  382  of the third duplicate wheel  100 . The loading bracket  44  mounts a traverse module (not shown) of the disc drive thereon. The cam slider  42  includes a horizontal portion  422  and a vertical portion  424 . The horizontal portion  422  is mounted on a top of the front beam  22  of the frame  2 , and the vertical portion  424  is attached to a rear of the front beam  22 .  
         [0024]     The horizontal portion  422  includes a guiding pin  220  and a toothed portion  222 . The guiding pin  220  extends upwardly from an upper surface (not labeled) of the horizontal portion  422 , near the driving motor  30 . The guiding pin  220  is engageable in the guiding groove  14  of the tray  1 . The toothed portion  222  is formed at a side of the horizontal portion  422 . The toothed portion  222  is engageable with the fifth gear  382  of the transmission system  3 . The toothed portion  222  includes a first rack segment  224  and a second rack segment  226 . A tooth height of the first rack segment  224  is smaller than that of the second rack segment  226 . The first rack segment  224  and the second rack segment  226  are spaced apart from each other by a notch  227 . A slot  228  communicating with the notch  227  is defined behind the first rack segment  224 , along a direction of a movement of the toothed portion  222 . Due to the slot  228  defined behind the first rack segment  224 , the first rack segment  224  can flexibly deform under an outside force.  
         [0025]     The vertical portion  424  defines therethrough a pair of generally Z-shaped channels  242 . The channels  242  each receive a post  442  (referring to  FIG. 3 ) extending horizontally from the loading bracket  44 . The engagement of the Z-shaped channels  242  and the posts  442  induces the loading bracket  44  to move up or down the traverse module, so as to load or unload a disc, as the cam slider  42  slides to the left or right.  
         [0026]     Referring to  FIG. 6 , a loading switch  24 , which controls direction of rotation of the driving motor  30  of the transmission system  3 , is attached to a bottom of the front beam  22 . A switch pusher  426  is formed on the vertical portion  424  of the cam slider  42 , for activating the loading switch  24  to switch between a first rotation direction and a second rotation direction, i.e. between a loading direction and an unloading direction.  
         [0027]     Referring to  FIG. 1  and  FIG. 6 , when loading a disc to the disc drive, the disc is placed on the tray  1  of the loading apparatus  999 . The driving motor  30  is activated, and a motive force is output to the first pulley  320  of the first transmission unit  32 . The motive force is sequentially transmitted to the first duplicate gear  60 , the second duplicate gear  80 , the third duplicate gear  100 , and the sixth gear  384 . Due to the engagement of the rack rail  12  of the tray  1  and the sixth gear  384 , the tray  1  with the disc thereon is driven to move towards the frame  2 .  
         [0028]     As the tray  1  moves into the frame  2 , the guiding pin  220  of the cam slider  42  in the guiding groove  14  gradually moves from the longitudinal portion  146  to the inclined portion  144 . This causes the cam slider  42  to move left, and the first rack segment  224  of the toothed portion  222  engages with the fifth gear  382  in advance of the second rack segment  226 . If the fifth gear  382  meshes properly with the first rack segment  224 , the fifth gear  382  then successively meshes with the second rack segment  226 . If a conflict of teeth of the fifth gear  382  and the first rack segment  224  occurs, the first rack segment  224  is flexibly deformed towards the cam slider  42 . That is, if a tooth of the fifth gear  382  conflicts with a tooth of the first rack segment  224 , the first rack segment  224  is forced to retreat toward the slot  228  therebehind. Accordingly, a relative displacement between the fifth gear  382  and the first rack segment  224  occurs.  
         [0029]     After that, the second rack segment  226  can successfully mesh with the fifth gear  382 , and engages smoothly and evenly with the fifth gear  382 . The cam slider  42  moves on under the engagement of the fifth gear  382  and the second rack segment  226 . The loading bracket  44  lifts up following sliding of the cam slider  42 , until the cam slider  42  slides to a predetermined position, where the switch pusher  426  pushes the loading switch  24  to cut off the power supply of the driving motor  30 . In this position, the tray  1  wholly enters the frame  2 , and the loading bracket  44  lifts up to a highest location to load the disc.  
         [0030]     As described above, the first rack segment  224  of the loading apparatus  999  overcomes the misalignment of teeth, and supplies a proper engagement to the second rack segment  226 . This configuration of toothed portion  222  can also be applied to other rack and gear units, or even gear and pinion units.  
         [0031]     It should be emphasized that the above-described embodiments of the present invention, including any preferred embodiments, are merely possible examples of implementation of the principles of the invention, and are merely set forth for a clear understanding of the principles of the invention. Many variations and modifications may be made to the above-described embodiments of the invention without departing substantially from the spirit and principles of the invention. All such modifications and variations are intended to be included herein within the scope of this disclosure and the present invention and be protected by the following claims.

Technology Classification (CPC): 6