Abstract:
A foldable supporting mechanism includes at least one hinge secured to a device, a bracket rotatably fixed to the device by the at least one hinge, and an elastic assembly secured to the at least one hinge. The supporting mechanism provides an elastic force to retain the bracket at an angle with the device when the bracket is unfolded. When the bracket is folded, the elastic assembly restores to continue urging the bracket to be fully retracted against the device. The at least one buffering assembly impedes the free rotation of the bracket relative to the device when the bracket is being unfolded and when it is being folded. An electronic device having the supporting mechanism is also provided.

Description:
BACKGROUND 
       [0001]    1. Technical Field 
         [0002]    The present disclosure relates to support mechanisms, and more particularly, to a support mechanism for an electronic device. 
         [0003]    2. Description of Related Art 
         [0004]    Electronic devices, such as tablet computers, include a main body and a support mechanism for supporting the main body on a support surface. The support mechanism is rotatably secured to a back surface of the main body. A torsion spring is arranged between the main body and the support mechanism. When the support mechanism is folded by an external force, the torsion spring is deformed to retain the support mechanism in the folded state. When the support mechanism is unfolded by an external force, the torsion spring restores to retain the support mechanism at a predetermined angle with the main body. However, when the support mechanism is to be put into the folded state, the deformed torsion spring may cause the support mechanism to snap shut, which may break the support mechanism, and possibly hurt the user. 
         [0005]    Therefore, there is room for improvement in the art. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]    Many aspects of the embodiments can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the embodiments. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views. 
           [0007]      FIG. 1  is a partial perspective view of an electronic device in accordance with an embodiment. 
           [0008]      FIG. 2  is similar to  FIG. 1 , but viewed from another aspect. 
           [0009]      FIG. 3  is a disassembled view of the electronic device in  FIG. 2 , the electronic device including a support mechanism. 
           [0010]      FIG. 4  is a partially disassembled view of the support mechanism in  FIG. 3 , the support mechanism including a buffering assembly. 
           [0011]      FIG. 5  is a disassembled view of the buffering assembly in  FIG. 4 . 
           [0012]      FIG. 6  is similar to  FIG. 5 , but viewed from another aspect. 
           [0013]      FIG. 7  is a cross section view of the buffering assembly in  FIG. 4 . 
           [0014]      FIG. 8  is a partially assembled view of the support mechanism in  FIG. 4 . 
       
    
    
     DETAILED DESCRIPTION 
       [0015]    The disclosure is illustrated by way of example and not by way of limitation in the figures of the accompanying drawings in which like references indicate similar elements. It should be noted that references to “an” or “one” embodiment in this disclosure are not necessarily to the same embodiment, and such references mean “at least one.” 
         [0016]    Referring to  FIGS. 1 and 2 , an electronic device  100  in accordance with an embodiment is shown. The electronic device  100  includes a main body  1  and a support mechanism  3  for supporting the main body  1  on a supporting surface, such as a desk. The electronic device  100  can be a PDA, a mobile telephone, a tablet computer, or the like. The electronic device  100  in the embodiment is a tablet computer. 
         [0017]    The main body  1  is substantially rectangular, and includes a front case  10  and a rear case  20 . The front case  10  engages with the rear case  20  to define a receiving space (not label) for receiving circuit board, DVD driver and other electronic components of the electronic device  100 . A display (not shown) is mounted to the front case  10 . Referring also to  FIG. 3 , a substantially rectangular protruding block  24  is secured to a back surface  210  of the rear case  20  opposite to the front case  10 . When viewed from the back surface  210 , the protruding block  24  protrudes from the back surface  210 ; while viewed from an inner surface  212  (see  FIG. 2 ) of the rear case  20  opposite to the back surface  210 , the protruding blocking  24  is a hollow structure, recessed from the inner surface  212  to define a cavity. The rear case  20  further defines two mounting holes  26  communicating with the receiving space. The mounting holes  26  are symmetrically arranged at opposite sides of the protruding block  24 . The mounting holes  26  are aligned parallel to and adjacent to the top edge  22  of the rear case  20 . 
         [0018]    The support mechanism  3  includes a bracket  5 , two hinges  6 , two elastic assemblies  7 , and two buffering assemblies  9 . The bracket  5  is rotatably secured to the main body  1  by the hinges  6 , and is foldable onto the back surface  210  of the rear case  20 . The elastic assemblies  7  are secured to the hinges  6 . The elastic assemblies  7  are capable of being deformed to retain the bracket  5  in a folded state on the back surface  210 , and is capable of restoring the bracket  4  to a predetermined support angle with the back surface  210 . The buffering assemblies  9  are secured to the hinges  6 , and are used for buffering the bracket  4  when forced by the deformed elastic assemblies  7 . 
         [0019]    The bracket  5  is substantially U-shaped, and is capable of being folded on the back surface  210 . When the bracket  5  is folded, the bracket  5  is coplanar with and surrounds a portion of the protruding block  24 . The bracket  5  includes a base  50  and two cantilevers  52  extending from opposite ends of the base  50 . 
         [0020]    The hinges  6  are secured to ends of the cantilevers  52  away from the base  50  and face each other. Each hinge  6  includes a shaft  54  fixed to a cantilever  52  and a pivot bracket  60  rotatably secured to the shaft  54 . The shaft  54  is substantially columnar. Opposite sides of a cross section of the shaft  54  are removed to form two parallel flat end portions  540 , the cross section of the shaft  54  then being substantially oval. The pivot bracket  60  includes a fixing plate  61  and two mounting plates  62 ,  63 . The fixing plate  61  is fixed to the inner surface  212 . The mounting plates  62 ,  63  extend from opposite ends of the fixing plate  61 . The mounting plates  62 ,  63  define two round holes  65 ,  70  for rotatably receiving the shaft  54 . An end of the mounting plate  62  adjacent to the fixing plate  61  defines a first latching hole  67 . The mounting plate  63  defines two limiting holes  72 . The limiting holes  72  are aligned with the round hole  70  and are symmetrical relative to the round hole  70 . An end of the mounting plate  63  away from the fixing plate  61  is substantially crenellated, and defines two recesses  68 . 
         [0021]    Each hinge  6  further includes a number of friction assemblies  8   a,    8   b,    8   c  and a positioning assembly  8   d.  The friction assemblies  8   a,    8   b,    8   c  and the positioning assembly  8   d  are sleeved on the shaft  54 . The friction assemblies  8   a  and  8   b  are mounted to opposite sides of the mounting plate  62 . The friction assemblies  8   c  and the positioning assembly  8   d  are mounted to opposite sides of the mounting plate  63 . Each friction assembly includes a first shim  811  and a second shim  813 . The first shim  811  defines a through hole  815  to fit the shaft  54 , to prevent the first shim  811  from rotating around the shaft  54 . The second shim  813  is secured to the mounting plate  62  and defines a round hole for rotatably receiving the shaft  54 , whereby the second shim  813  is capable of rotating with the pivot bracket  60  around the shaft  54 . The positioning assembly  8   d  includes a second shim  881  fixed to the mounting plate  63  and a positioning member  883 . The structure of the second shim  881  and the structure of the first shim  811  are the same. The second shim  881  is sleeved on the shaft  54  and is rotatable around the shaft  54 . The positioning member  883  defines a positioning hole  888  to fit the shaft  54 , to prevent the positioning member  883  from rotating around the shaft  54 . A positioning post  889  is secured to a rim of the positioning member  883 . The positioning post  889  is capable of sliding between the two recesses  68  defined on the mounting plate  63 . As the positioning member  883  rotates with the shaft  54 , when the positioning post  889  slides between the recesses  68 , the shaft  54  is positioned in two different orientations relative to the pivot bracket  60 . 
         [0022]    Each elastic assembly  7  includes a sleeve  76 , an elastic member  77 , and a limiting member  78 . The sleeve  76  is substantially hollow and columnar. The sleeve  76  is arranged between the mounting plates  62 ,  63  and is sleeved on the shaft  54 . The limiting member  78  is arranged between the sleeve  76  and the friction assembly  8   c.  The limiting member  78  defines an engaging hole  783  receiving the shaft  54 , to prevent the limiting member  78  from rotating around the shaft  54 . The limiting member  78  further defines a second latching hole  785  spaced apart from the engaging hole  783 . The elastic member  77  in the embodiment is a torsion spring  77 , includes a spiral spring  771 , and two arms  770 ,  772  extending from opposite ends of the spiral spring  771 . The arm  770  is mounted to the first latching hole  67 , and the arm  772  is mounted to the second latching hole  785 . 
         [0023]    The buffering assemblies  9  is sleeved on the shaft  54  and abut ends of the positioning members  883  away from the pivot bracket  60 . Referring to  FIGS. 5 and 6 , each buffering assembly  9  includes a front cover  91 , two gaskets  93 ,  97 , a wheel  95 , and a fixing member  99 . The front cover  91  is substantially disk shaped. A first protruding ring  916  extends from an end of the front cover  91 . The centre of the front cover  91  defines a first receiving hole  912  axially extending through the first protruding ring  916 . The first receiving hole  912  rotatably receives the shaft  54 , thereby the front cover  91  is rotatably sleeved on the shaft  54 . A portion of an inner sidewall of the first protruding ring  916  is removed to define a first step  917 . The first step  917  is coaxial with the first protruding ring  916 . A second protruding ring  915  further protrudes from the front cover  91 . The second protruding ring  915  is coaxial with and spaced apart from the first protruding ring  916 , to define a receiving groove  919 . 
         [0024]    The wheel  95  is sleeved on the shaft  54  and rotates with the shaft  54 . The wheel  95  includes a cylinder  952  and a flange  950  protruding from the cylinder  952 . The cylinder  952  defines a fixing hole  954  extending longitudinally. The fixing hole  954  fits the shaft  54 , to prevent the wheel  95  from rotating with the shaft  54 . The diameter of the cylinder  952  is slightly less than the diameter of the first receiving hole  912 . The flange  950  is substantially disk shaped, and extends radially outward from the middle of the cylinder  952 . The diameter of the flange  950  is equal to the outer diameter of the protruding ring  916 . 
         [0025]    The fixing member  99  is substantially cylindrical. The fixing member  99  is recessed to define a first groove  993  and a second groove  998 . The first groove  993  and the second groove  998  are coaxial. The first groove  993  is spaced apart from the second groove  998 , with a ring-shaped engaging portion  997  arranged therebetween. The first groove  993  fits the second protruding ring  915 . The second groove  998  fits the first protruding ring  916 . The bottom of the second groove  998  is recessed to define a circular recess  995 . The bottom of the circular recess  995  further defines a second receiving hole  991  axially extending through the fixing member  99 . The diameter of the recess  995  is greater than the diameter of the second receiving hole  991 , whereby a second step  999  is formed. The diameter of the second receiving hole  991  is equal to the diameter of the first receiving hole  912 . The diameter of the second step  999  is equal to the diameter of the first step  917 . Two fixing posts  992  are secured to the sidewall of the fixing member  99 . The fixing posts  992  are spaced apart from each other, and correspond to the limiting holes  72 . 
         [0026]    The gaskets  93 ,  97  are secured to the first and second steps  917 ,  999 . The diameter of the gaskets  93 ,  97  is slightly greater than or equal to the diameter of the cylinder  952 , thus when ends of the cylinder  952  are received in the first and second receiving holes  912 ,  991 , the joint of the cylinder  952  and the sidewall of the first receiving hole  912 , and the joint of the cylinder  952  and the sidewall of the second receiving hole  991  are sealed by the gaskets  93 ,  96  to avoid leakage of oil or other fluid. 
         [0027]    Referring to  FIG. 7 , in assembly of the buffering assembly  9 , first, the gaskets  93 ,  97  are secured to the first and second steps  917 ,  999 ; second, the fixing posts  992  are received in the limiting holes  72 ; third, an end of the cylinder  952  is inserted into the second receiving hole  991 , the other end of the cylinder  952  being inserted into the first receiving hole  912 ; finally, the front cover  91  resists the wheel  5  against the fixing member  99 , and further engages with the second cover  99  with the second protruding ring  915  fitting into the first groove  993  and the first protruding ring  916  fitting into the second groove  998 , to define a close space for receiving the flange  950  therein, and the clearance between the front cover  91  and the fixing member  99  is filled with damping oil or fluid for buffering when the wheel  95  rotates with the shaft  54 . 
         [0028]    Referring to  FIG. 8 , after the buffering assembly  9  is assembled, the pivot bracket  60  is fixed to the inner surface  212  of the rear case  20 . The elastic member  77  is sleeved on the sleeve  76  with opposite arms  770 ,  772  being fixed to the first and second latching holes  67 ,  785 . The shafts  54  extend through the fixing hole  954 , the positioning assembly  8   d,  the round hole  70  on the mounting plate  63 , the friction assembly  8   c,  the engaging hole  783 , the sleeve  76 , the friction assembly  8   b,  the round hole  65  on the mounting plate  62 , the friction assembly  8   a  in order, and is further fixed to the cantilevers  52 . Finally, nuts (not labeled) are threaded to ends of the shaft  54  and abut the buffering assemblies  9 . 
         [0029]    After assembly, the fixing member  99  is secured to and rotates with the pivot bracket  60 , the wheel  95  rotates with the shaft  54 , thus, when the shaft  54  rotates with the pivot bracket  60 , a frictional force is generated between the wheel  95  and the fixing members  91 ,  99 , to impede free rotation of the shaft  54 . Furthermore, the first shim  811  abuts the second shim  813 , the first shim  811  rotates with the shaft  54 , and the second shim  813  rotates with the pivot bracket  60 , thus when the shaft  54  rotates with the pivot bracket  60 , another frictional force source is created between the first and second shims  811 ,  813  to further impede free rotation of the shaft  54 . As a result, when the bracket  5  is unfolded, the elastic assembly  7  restores the bracket  5  against the back surface  210  of the rear case  20 . At the same time, the buffering assembly  9  and the friction assemblies  8   a ,  8   b,    8   c  generate frictional forces to slow down the rotation of the shaft  54  relative to the pivot bracket  60 , thus the bracket  5  is prevented from abruptly stopping. 
         [0030]    Although information as to, and advantages of, the present embodiments have been set forth in the foregoing description, together with details of the structures and functions of the present embodiments, the disclosure is illustrative only; and changes may be made in detail, especially in the matters of shape, size, and arrangement of parts within the principles of the present embodiments to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.