Abstract:
A hinge includes a first leaf, a pivot shaft mounted to the first leaf, a first knuckle rotatably mounted to the shaft, a second leaf rotatably mounted to the shaft, a resilient assembly mounted to the shaft, and a fastener fixed to the shaft. One end of the first knuckle forms an engaging portion, and the second leaf correspondingly forms a tab to engage with the engaging portion. Upon the condition that the tab engages with the engaging portion such that the first knuckle can rotate with the second leaf, a larger twisting force is needed for the second leaf, together with the first knuckle, to rotate relative to the pivot shaft due to further overcome a friction between the first knuckle and the pivot shaft.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    A relevant subject matter is disclosed in a co-pending U.S. patent application (Attorney Docket No. US30358) filed on the same date and entitled “HINGE,” which is assigned to the same assignee as this patent application. 
       BACKGROUND 
       [0002]    1. Technical Field 
         [0003]    The present disclosure relates to a hinge. 
         [0004]    2. Description of Related Art 
         [0005]    A foldable device, such as a notebook computer, or a foldable mobile phone, generally includes a base and a cover pivotably mounted to the base via a hinge. The hinge generally includes a pivot shaft, a first leaf, and a second leaf. The first leaf is mounted to the base, and the second leaf is mounted to the cover. A twisting force is required to overcome a friction between the second leaf and the pivot shaft to rotate the cover relative to the base. However, the friction between the second leaf and the pivot shaft remains the same when the device is unfolded. The twisting force required also remains the same, which gives a user an uneasy feeling. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]      FIG. 1  is an exploded, isometric view of a first exemplary embodiment of a hinge. 
           [0007]      FIG. 2  is similar to  FIG. 1 , but viewed from another perspective 
           [0008]      FIG. 3  is an assembled, isometric view of the hinge of  FIG. 2 . 
           [0009]      FIG. 4  is similar to  FIG. 3 , but showing a different state. 
           [0010]      FIG. 5  is an exploded, isometric view of a second exemplary embodiment of a hinge. 
           [0011]      FIG. 6  is similar to  FIG. 4 , but viewed from another perspective. 
           [0012]      FIG. 7  is an assembled, isometric view of the hinge of  FIG. 6 . 
           [0013]      FIG. 8  is similar to  FIG. 7 , but showing a different state. 
       
    
    
     DETAILED DESCRIPTION 
       [0014]    Referring to  FIGS. 1 and 2 , a first exemplary embodiment of a hinge includes a pivot shaft  10 , a first leaf  20 , a second leaf  30 , a first knuckle  40 , a resilient assembly  50 , two washers  60 , and a fastener  70 . 
         [0015]    The pivot shaft  10  includes a fixing rod  12  having a substantially non-circular cross-section. A first end of the fixing rod  12  forms a threaded portion  120 , and a second end of the fixing rod  12  opposite to the first end forms a non-circular combination block  16 . A cylindrical flange  14  extends between the non-circular combination block  16  and the fixing rod  12 . 
         [0016]    The first leaf  20  is fixed to a base of a foldable device (not shown), such as a notebook computer, and includes a combination portion  22 . The combination portion  22  defines a non-circular fixing hole  24  corresponding to the non-circular combination block  16 . 
         [0017]    The second leaf  30  is fixed to a cover of the foldable device, and includes a second knuckle  32 . The second knuckle  32  includes a first end surface  34  facing the first knuckle  40 , and a second end surface  36  opposite to the first end surface  34 . A round through hole  38  is defined in a center of the second knuckle  32 . The fixing rod  12  of the pivot shaft  10  extends through the round through hole  38 . A tab  340  extends from a side of the first end surface  34 . The tab  340  may be arc-shaped. Two engaging surfaces  342  are formed on opposite ends of the tab  340 . 
         [0018]    The first knuckle  40  fits about the cylindrical flange  14 . The first knuckle  40  defines an incision  42  parallel with an axial direction of the first knuckle  40 . An engaging portion  44  is formed on a first end of the first knuckle  40 , extending from the incision  42 , facing the second knuckle  32 . The engaging portion  44  is corresponding to the tab  340 . Two engaging surfaces  442  are formed on opposite ends of the engaging portion  44 . 
         [0019]    The resilient assembly  50  includes a plurality of elastic elements stacked together. Each elastic elements defines a round through hole  52  through which the fixing rod  12  extends. 
         [0020]    Each washer  60  includes a first end surface  62  facing the second knuckle  32  of the second leaf  30 , and a second end surface  64  opposite to the first end surface  62 . A non-circular through hole  66  is defined in a center of the washer  60 . The through hole  66  is through the first end surface  62  and the second surface  64 . The fixing rod  12  extends through the through hole  66 . 
         [0021]    In one embodiment, the fastener  70  is a screw cap. 
         [0022]    Referring to  FIG. 3 , during assembly, the combination block  16  is received and fixed in the fixing hole  24 . The first knuckle  40 , the second leaf  30 , one washer  60 , the plurality of elastic elements of the resilient assembly  50 , and the other washer  60  are sleeved on the pivot shaft  10  in that order. The first knuckle  40  fits about the cylindrical flange  14 . The first end surface  34  engages an end of the cylindrical flange  14 . The fastener  70  engages with the threaded portion  120 , thus fixing the fastener  70  to the pivot shaft  10 , to prevent the washers  60 , the resilient assembly  50 , the second leaf  30 , and the first knuckle  40  from disengaging from the pivot shaft  10 . 
         [0023]    Referring to  FIG. 4 , to open the foldable device from a folded/closed state, initially, a twisting force f 1  is required to overcome a friction between the second end surface  36  and the first end surface  62  of the washer  60 , a friction between the second leaf  30  and the fixing rod  12 , and a friction between the first end surface  34  and the cylindrical flange  14 , to rotate the second leaf  30  relative to the pivot shaft  10 . When one of the engaging surfaces  342  of the second leaf  30  engages one of the engaging surfaces  442  of the first knuckle  40 , a twisting force f 2  is required to simultaneously rotate the second leaf  30  and the first knuckle  40  relative to the pivot shaft  10 . Obviously, the twisting force f 2  further overcomes a friction between the first knuckle  40  and the cylindrical flange  14 . Therefore, the twisting force f 2  is larger than the twisting force f 1 . 
         [0024]    To close the foldable device from a unfolded/opened state, initially, the twisting force f 1  is required to rotate the second leaf  30  relative to the pivot shaft  10 . When the other engaging surface  342  of the second leaf  30  engages the other engaging surface  442  of the first knuckle  40 , the twisting force f 2  is required to simultaneously rotate the second leaf  30  and the first knuckle  40  relative to the pivot shaft  10 . 
         [0025]    Referring to the  FIGS. 5 and 6 , a second exemplary embodiment of a hinge includes a first leaf  80  and a first knuckle  90 . Other structures of the second exemplary embodiment of the hinge are similar to the first exemplary embodiment of the hinge. 
         [0026]    The first leaf  80  is fixed to the base of the foldable device, and includes a combination portion  82 . The combination portion  82  defines a non-circular hole fixing hole  84 , corresponding to the non-circular combination block  16 . A positioning portion  86  extends from a side of the combination portion  82 , facing to the first knuckle  90 . The positioning portion  86  is arc-shaped. Two positioning surfaces  862  are formed on opposite ends of the positioning portion  86 . 
         [0027]    The first knuckle  90  fits about the cylindrical flange  14 . The first knuckle  90  defines an incision  92  parallel with an axial direction of the first knuckle  90 . An engaging portion  94  and an blocking portion  96  are staggeredly formed on two opposite ends of the first knuckle  90 , reversely extending from the incision  92 . The engaging portion  94  is corresponding to the tab  340 . The blocking portion  96  is corresponding to the positioning portion  86 . The engaging portion  94  faces the second knuckle  32 . The blocking portion  96  faces the combination portion  82 . Two engaging surfaces  942  are formed on opposite ends of the engaging portion  94 . Two blocking surfaces  962  are formed on opposite ends of the blocking portion  96 . 
         [0028]    Referring to  FIG. 7 , during assembly, the combination block  16  is received and fixed in the fixing hole  84 . The first knuckle  90 , the second leaf  30 , one washer  60 , the plurality of elastic elements of the resilient assembly  50 , and the other washer  60  is sleeved on the pivot shaft  10  in that order. The first knuckle  90  fits about the cylindrical flange  14 . The first end surface  34  of the second leaf  30  engages an end of the cylindrical flange  14 . The fastener  70  engages with the threaded portion  120  of the pivot shaft  10 , thus fixing the fastener  70  to the pivot shaft  10 , to prevent the washers  60 , the resilient assembly  50 , the second leaf  30 , and the first knuckle  90  from disengaging from the pivot shaft  10 . 
         [0029]    Referring to  FIG. 8 , to open the foldable device from a folded/closed state, initially, a twisting force f 3  is required to overcome a friction between the second end surface  36  and the first end surface  62  of the washer  60 , a friction between the second leaf  30  and the fixing rod  12 , and a friction between the first end surface  34  and the cylindrical flange  14 , to rotate the second leaf  30  relative to the pivot shaft  10 . When one of the engaging surfaces  342  of the bracket  30  engages one of the engaging surfaces  942  of the first knuckle  90 , a twisting force f 4  is required to simultaneously rotate the second leaf  30  and the first knuckle  90  relative to the pivot shaft  10 . Obviously, the twisting force f 4  further overcomes a friction between the first knuckle  90  and the cylindrical flange  14 . The twisting force f 4  is larger than the twisting force f 3 . When one of the blocking surfaces  962  engages with one of the positioning surfaces  862  of the first leaf  80 , the first leaf  80  prevents the second leaf  30  and the first knuckle  90  from simultaneously rotating relative to the pivot shaft  10 . 
         [0030]    To close the foldable device from a unfolded/opened, initially, the twisting force f 3  is required to rotate the second leaf  30  relative to the pivot shaft  10 . When the other engaging surface  342  of the bracket  30  engages the other engaging surface  942  of the first knuckle  90 , the twisting force f 4  is required to simultaneously rotate the second leaf  30  and the first knuckle  90  relative to the pivot shaft  10 . 
         [0031]    It is to be understood, however, that even though numerous characteristics and advantages of the present disclosure have been set forth in the foregoing description, together with details of the structure and function of the disclosure, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the disclosure to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.