Abstract:
An exemplary sliding mechanism ( 10 ) includes a main plate ( 11 ), a slide plate ( 12 ) slidably connected to the main plate ( 11 ), and a linkage module positioned between the main plate ( 11 ) and the slide plate ( 12 ). The linkage module includes an elastic member ( 15 ) and a guiding shaft ( 17 ). The elastic member ( 15 ) is sleeved on the guiding shaft ( 17 ). Two ends of the guiding shaft ( 17 ) is rotatably connected to the main plate ( 11 ) and the slide plate ( 12 ) respectively. The elastic member ( 15 ) is configured for driving the slide plate ( 12 ) and enabling the slide plate ( 12 ) to slide along the main plate ( 11 ) after the slide plate ( 12 ) is manually moved to a predetermined position with respect to the main plate ( 11 ).

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention generally relates to sliding mechanisms, and more particularly, to a sliding mechanism used for a portable electronic device with two or more housings. 
     2. Discussion of the Related Art 
     Sliding mechanisms are widely used in portable electronic devices, such as mobile phones and personal digital assistants (PDAs). Referring to  FIG. 8 , a typical sliding mechanism generally includes a first plate  50 , a second plate  60 , and a linkage module (not labeled) configured for linking the first plate  50  and the second plate  60 . The first plate  50  and the second plate  60  are substantially rectangular in shape. The linkage module includes two fixing members  52 , two shafts  62 , two rails  65 , and two springs  67 . The fixing members  52  are fixed to the center portion of the second plate  60  and aligned along a same line. Each fixing member  52  defines a through hole (not labeled) therein. The shafts  62  are fixed adjacent to opposite sides of the first plate  50  respectively. An end of each rail  65  is slidably inserted through the through hole of the fixing members  52 , and an opposite end of each rail  65  is rotatably connected to the shafts  62 . The rails  65  are rotatable about an axis of the corresponding shafts  62 . Each spring  67  is sleeved on the corresponding rails  65  between the fixing members  52  and the shafts  62 . 
     In use, in a starting position, the second plate  60  is at an end of the second plate  60 , and the second plate  60  is open or closed relative to the first plate  50 . When the second plate  60  of sliding mechanism  100  is pushed by an external force, the second plate  60  is moved relative to the first plate  50 . As such, the fixing members  52  are moved together with the second plate  60 . At this time, the rails  65  slide relative to the through hole of the fixing members  52 , and rotate about the axes of the shafts  62 . A distance between the fixing members  52  and the shafts  62  is decreased. Thus, the spring  67  becomes compressed and accumulates potential energy until the second plate  60  reaches the middle of the first plate  50 . When the second plate  60  is pushed across the middle of the first plate  50 , the external force is removed. The potential energy of the springs  67  is released and pushes the second plate  60  to slide further, until the second plate  60  is closed or open relative to the first plate  50 . 
     However, the sliding mechanism causes several problems. Firstly, since the springs  67  are disposed above the first plate  50  and the second plate  60 , when the sliding mechanism is employed in an electronic device and the second plate  60  slides relative to the first plate  50 , the springs  67  may be blocked by other components of the electronic device. Thus, the sliding mechanism cannot be normally operated, and the springs  67  may be damaged. Secondly, two rails  65  require a relatively large space for movement. Thirdly, the first plate  50  and the second plate  60  are disposed on a same side of the rails  65  and the spring  67 . A width of the first plate  50  should be larger than that of the second plate  60  so that the shafts  62  can be fixed to the first plate  50 . Therefore, the sliding mechanism occupies a relatively large volume. Fourthly, the linkage module of the sliding mechanism includes so many components, causing high production costs. 
     What is needed, therefore, is a sliding mechanism which overcomes the above-described shortcomings. 
     SUMMARY 
     An exemplary sliding mechanism includes a main plate, a slide plate slidably connected to the main plate, and a linkage module positioned between the main plate and the slide plate. The linkage module includes an elastic member and a guiding shaft. The elastic member is sleeved on the guiding shaft. Two ends of the guiding shaft are rotatably connected to the main plate and the slide plate respectively. The elastic member is configured for driving the slide plate to slide along the main plate after the slide plate is manually moved to a predetermined position with respect to the main plate. 
     Other advantages and novel features will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present sliding mechanism and portable electronic device. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views, and all the views are schematic. 
         FIG. 1  is an isometric view illustrating a closed state of a sliding-type portable electronic device in accordance with a first exemplary embodiment of the present invention. 
         FIG. 2  is similar to  FIG. 1 , but showing an opened state of the present sliding-type portable electronic device. 
         FIG. 3  is an exploded, isometric view of a sliding mechanism used for the sliding-type portable electronic device of  FIG. 1 , including a slide plate and a main plate. 
         FIG. 4  is an assembled, isometric view of the sliding mechanism of  FIG. 3 , showing the slide plate in a closed position relative to the main plate. 
         FIG. 5  is similar to  FIG. 4 , but showing the slide plate in a half-closed position relative to the main plate. 
         FIG. 6  is similar to  FIG. 5 , but showing the slide plate in an open position relative to the main plate. 
         FIG. 7  is an assembled, isometric view of a sliding mechanism in accordance with a second exemplary embodiment of the present invention. 
         FIG. 8  is an assembled, isometric view of a typical sliding mechanism. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Reference will now be made to the drawings to describe embodiments of the present sliding mechanism in detail. 
     Referring to  FIGS. 1 through 3 , a sliding mechanism  10  according to a first exemplary embodiment of the present invention is adapted for use in portable electronic device  200 . The portable electronic device  200  includes a first housing  210 , a second housing  212  engaging with the first housing  210  and a sliding mechanism  10 . The sliding mechanism  10  is positioned between the first and second housings  210 ,  212  for making the second housing  212  slidable relative to the first housing  210 . The first housing  210  is provided, at a front surface thereof, with a keypad  214 . The second housing  212  is provided, at a front surface thereof, with a display  216  and a plurality of function keys  218 . The second housing  212  slides relative to the first housing  210 , thus exposing or covering the keypad  214 . 
     The sliding mechanism  10  includes a main plate  11 , a slide plate  12 , a pair of guiding rails  14 , an elastic member  15 , and a guiding shaft  17 . The main plate  11  and the slide plate  12  are respectively fixed to the first housing  210  and the second housing  212 . 
     The main plate  11  of the sliding mechanism  10  is substantially rectangular and includes a main body  112 . A pair of slide portions  114  extends from the two opposite long sides of the main body  112  respectively. The main body  112  defines an oblong hole  116  adjacent to an end portion thereof and a pinhole  118 . The oblong hole  116  is configured for assembling the sliding mechanism  10  easily. The pinhole  118  is adjacent to the slide portions  114  and approximately in the middle of the main plate  11 . 
     The slide plate  12  of the sliding mechanism  10  is substantially rectangular sheet-shaped. The slide plate  12  defines an engaging hole  126  approximately in the center thereof. The width of a first side  120  of the slide plate  12  is approximately the same as that of a shorter side of the main plate  11 . Two second sides  122  are respectively oriented perpendicular to the first end  120  and are opposite and parallel to one another. An arcuate sidewall  123  extends from each second side  122 , thereby defining a receiving groove  124  for receiving the guiding rails  14  of the sliding mechanism  10  respectively. Each arcuate sidewall  123  defines a latching hole  128 . 
     The guiding rails  14  are substantially rail-shaped. A first sidewall (not labeled) of each of the guiding rails  14  defines a guiding slot  143 , and a second sidewall (not labeled) opposite to the first sidewall forms a latching protrusion  142 . The latching protrusions  142  engage with the latching holes  128  of the slide plate  12  so that the guiding rails  14  may move together with the slide plate  12 . The elastic member  15  is a helical spring, and is extendable and compressible. 
     The guiding shaft  17  includes a connecting portion  171  and a shaft portion  172 . A length of the guiding shaft  17  is slightly smaller than a width of the main body  112  of the main plate  11 . The connecting portion  171  is formed on an end of the shaft portion  172 , and the connecting portion  171  defines an engaging hole  174  in the center thereof. A cylindrical surface of an opposite end of the shaft portion  172  defines a fixing groove  173 . 
     The sliding mechanism  10  further includes a first rivet  16 , a second rivet  18 , a rivet sleeve  19  and a fixing member  21 . Each of the second rivet  18  and the rivet sleeve  19  defines a through hole (not labeled). The through holes extend through the second rivet  18  and the rivet sleeve  19  respectively, i.e., each through hole has an axis perpendicular to an axis of the corresponding second rivet  18  and the rivet sleeve  19 . The opposite end of the shaft portion  172  of the guiding shaft  17  is configured for inserting into the through holes of the second rivet  18  and the rivet sleeve  19 . 
     The fixing member  21  is substantially a C-shaped clip. The fixing member  21  is configured for engaging in the fixing groove  173  of the guiding shaft  17 . 
     In assembly of the sliding mechanism  10 , the guiding rails  14  are received in the receiving grooves  124  of the slide plate  12  respectively, with the latching protrusions  142  of the guiding rails  14  engaging with the latching holes  128  of the slide plate  12 . An end of the guiding shaft  17  is rotatably attached to the main plate  11 , via the first rivet  16  engaging in the engaging hole  174  of the guiding shaft  17  and the pinhole  118  of the main plate  11 . Thus, the guiding shaft  17  is attached to the main plate  11 . The elastic member  15  is sleeved on the shaft portion  172  of the guiding shaft  17 . After that, the slide portions  114  of the main plate  11  are inserted into the guiding slots  143  of the guiding rails  14  respectively, so that the guiding rails  14  are slidably connected to the main plate  11 . As such, the slide plate  12  is slidable relative to the main plate  11  because the slide plate  12  is attached to the guiding rails  14 . 
     Next, the second rivet  18  is inserted into the engaging hole  126  of the slide plate  12  and the rivet sleeve  19 . The second rivet  18  and the rivet sleeve  19  are rotatably connected to the slide plate  12 . Then, the opposite end of the guiding shaft  17  protrudes through the pinholes of the second rivet  18  and the rivet sleeve  19 . The fixing member  21  engages in the fixing groove  173  of the guiding shaft  17 , thereby preventing the guiding shaft  17  from detaching from the second rivet  18  and the rivet sleeve  19 . The guiding shaft  17  is slidable relative to the second rivet  18  and the rivet sleeve  19 . Thus, the sliding mechanism  10  is completely assembled, with two ends of the elastic member  15  abutting the connecting portion  171  of the guiding shaft  17  and a sidewall of the rivet sleeve  19  respectively. 
     When the sliding mechanism  10  is employed in the portable electronic device  200 , the first housing  210  of the portable electronic device  200  is firmly secured to the main plate  11 , and the second housing  212  of the portable electronic device  200  is firmly secured to the slide plate  12 . The portable electronic device  200  may be selectively opened or closed. In use,  FIG. 4  shows the slide plate  12  in a closed position relative to the main plate  11 ,  FIG. 5  shows the slide plate  12  in a half-closed position relative to the main plate  11 , and  FIG. 6  shows the slide plate  12  in an open position relative to the main plate  11 . 
     Referring to  FIG. 4 , the slide plate  12  is at an end of the main plate  11 , the elastic member  15  is in an original state and a distance between the first and second rivet  16 ,  18 , respectively, is maximum. Referring also to  FIG. 1 , when the second housing  212  is pushed along a direction of the arrow shown in  FIG. 1 , that is toward an open position as shown in  FIG. 2 , the slide plate  12  slides relative to the main plate  11  as indicated by a direction of the arrow shown in  FIG. 5 . Therefore, the slide plate  12  together with the guiding rails  14  slide along the slide portions  114  of the main plate  11 . The distance between the first rivet  16  and the second rivet  18  decreases and the guiding shaft  17  slides relative to the second rivet  18  and the rivet sleeve  19 . The elastic member  15  is compressed, accumulating elastic force, and reaches the strongest elastic force when the slide plate  12  reaches the middle of the main plate  11 . 
     As shown in  FIG. 5 , the elastic member  15  is most compressed in the middle of the main plate  11  and thereby storing a maximum elastic force. At this time, if the second housing  212  is pushed longitudinally in either direction away from the middle, the elastic force of the elastic member  15  is released along the direction of movement and the slide plate  12  slides under the influence of the elastic force of the elastic member  15  to either the open position of  FIG. 6  or the closed position of  FIG. 4 . 
     If the movement continues in the direction as indicated by the arrow in  FIG. 5  the second housing  212  is fully opened, relative to the first housing  210 . The guiding shaft  17  is unable to slide relative to the second rivet  18  and the rivet sleeve  19  further. Consequently, as shown in  FIG. 2 , the keypad  214  on the first housing  210  is exposed for use. The slide plate  12  is in the open position relative to the main plate  11 . The process of closing the second housing  212  is the reverse of the opening process. 
     In this embodiment, the elastic member  15  is positioned between the main plate  11  and the slide plate  12 . Therefore, when the slide plate  12  slides relative to the main plate  11 , the elastic member  15  will not come into contact with other components of the portable electronic device  200 . Thus, the portable electronic device  200  is convenient to be operated. The sliding mechanism  100  includes a single elastic member  15  and a single guiding shaft  17  such that components of the sliding mechanism  100  are relatively few. Accordingly, the sliding mechanism  100  is easily assembled. In addition, the single guiding shaft  17  occupies a relatively small space for moving, and the space required in an application such as the portable electronic device  200  is reduced. 
     It should be pointed out that, the slide plate  10  and the main plate  20  can be integrally formed with the second housing  40  and the first housing  10  respectively. 
     Alternatively, the fixing member  21  may be some other type of fixing member such as a nut. With the condition, the fixing groove  173  of the guiding shaft  17  may be omitted, and the guiding shaft  17  defines a threaded hole corresponding to the nut. The slide plate  12  and the main plate  11  can be integrally formed with the second housing  212  and the first housing  210  respectively. The guiding rails  14  can be integrally formed with the slide plate  12 . 
     Referring to  FIG. 7 , a sliding mechanism  30  is provided according to a second exemplary embodiment of the present invention. The sliding mechanism  30  includes a main plate  31 , a slide plate  32 , an elastic member  35 , a first rivet  36 , a guiding shaft  37 , a second rivet  38 , and a rivet sleeve  39 . A connecting portion  371  is formed on an end of the guiding shaft  37 . The sliding mechanism  30  is similar in principle to the sliding mechanism  10 , except that the connecting portion  371  of the guiding shaft  37  is rotatably connected to the slide plate  32  via the first rivet  36  inserted through the connecting portion  371  and the slide plate  32 , and an opposite end of guiding shaft  37  protrudes through the second rivet  38  and the rivet sleeve  39  after the second rivet  38  and the rivet sleeve  39  is rotatably connected to the main plate  31 . 
     It is believed that the present embodiments and their advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the examples hereinbefore described merely being preferred or exemplary embodiments of the invention.