Patent Publication Number: US-7913359-B2

Title: Automatically opening hinge assembly for portable electronic devices

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to hinge assemblies and, particularly, to an automatically opening hinge assembly for foldable devices such as portable telephones, portable computers, and so on. 
     2. Discussion of the Related Art 
     At present, perhaps the most popular mobile phone in the marketplace is the foldable mobile phone, which generally includes a cover section and a body section. The cover section and the body section are rotatably interconnected through a hinge assembly, for switching the telephone between an in-use position and a closed position. 
     Typically, the hinge assembly employs a cam and a follower, which allows the cover section to fold outwards from the body section and then hold in an open position. The hinge assembly typically includes a cam having a concave portion, a follower having a convex portion, a shaft having a fixing end, and a spring. The cam and the follower are placed around the shaft. The spring resists the follower allowing the concave portion to tightly contact with the convex portion. The cam, the follower, the shaft and the spring are received in a housing. A cover rotates about a main body of the mobile phone by overcoming the force of the spring, thus allowing the concave portion to rotate about the convex portion. However, a user must open the mobile phone using both hands. This makes the mobile phone inconvenient to use in situations when the user has only one hand free. 
     Therefore, a new hinge mechanism is desired in order to overcome the above-described problems. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Many aspects of the hinge assembly can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, the emphasis instead being placed upon clearly illustrating the principles of the present hinge assembly. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views. 
         FIG. 1  is an isometric view of an exemplary embodiment of the present hinge assembly, as used in a mobile phone; 
         FIG. 2  is an exploded, isometric view of the exemplary embodiment of the hinge assembly shown in  FIG. 1 ; 
         FIG. 3  is similar to  FIG. 2 , but viewed from another aspect; 
         FIG. 4  is an enlarged view of the cam in  FIG. 2 ; 
         FIG. 5  is an enlarged view of the follower in  FIG. 2 ; 
         FIG. 6  is a cross-sectional view of the fixing seat in  FIG. 2 ; 
         FIG. 7  is an enlarged view of the fixing seat in  FIG. 2 ; 
         FIG. 8  is an partially assembled view showing the hinge assembly in  FIG. 2 ; 
         FIG. 9  is an assembled view showing the hinge assembly in  FIG. 2 ; 
         FIG. 10  is similar to  FIG. 9 , but viewed from another aspect; and 
         FIG. 11  is a cut-away view of  FIG. 10  along X-X line. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       FIG. 1  shows a hinge assembly  100 , applied to an exemplary foldable electronic device  50  such as a flip type mobile phone, for pivotably coupling a cover section  52  and a body section  54 . It is to be understood, however, that the hinge assembly  100  could be advantageously used in other environments (e.g. cabinet doors). As such, the hinge assembly  100  should not be considered limited in scope solely to foldable electronic devices. 
     Referring to  FIGS. 2 and 3 , the hinge assembly  100  of the present embodiment includes a securing structure  10 , a sleeve  11 , a first spring  12 , a shaft  13 , a cam  14 , a follower  15 , a second spring  16 , a control member  17 , a fixing seat  18 , a return spring  19  and a pressing element  20 . The first spring  12  and the cam  14  surround the shaft  13  at one end. The follower  15 , the second spring  16 , and the control member  17  are positioned on the other end of the shaft  13  opposite to the cam  14 , in the order written. The sleeve  11  receives the above-mentioned elements. The securing structure  10  is fixed on one end of the shaft  13  with the cam  14 , and the fixing seat  18  is fixed on the other end of the shaft  13 . The pressing element  20  is further received in the fixing seat  18 . Accordingly, the hinge assembly  100  is thus integrated into a single assembly. 
     The securing structure  10  includes a washer  101  and an anti-friction element  103 . The washer  101  and the anti-friction element  103  are substantially disk-shaped. The washer  101  defines a square hole  1011  in a central area thereof. The anti-friction element  103  defines a circular/round hole  1031  in a central area thereof. 
     The sleeve  11  is substantially a hollow cylinder having an outer wall  111  and an inner wall  112 . Two troughs  114  are defined in an inner wall  112  of the sleeve  11  along a longitudinal direction thereof. Two sleeve blocks  113  formed on the outer wall  111  correspond to the troughs  114 . The sleeve blocks  113  engage the cover section  52  of the mobile phone  50  so that the sleeve  11  and the cover section  52  cannot rotate relative to each other. The sleeve  11  includes an open end and a partially-closed end. The partially-closed end of the sleeve  11  defines a through-hole  115  at a central area thereof. 
     The first spring  12  is a cylindrical helical spring (i.e., occupying a cylindrical volume). The first spring  12  is sized to be received in the sleeve  11 . 
     The shaft  13  sequentially includes a shaft portion  132 , a screw portion  131  and an end portion  133 . The end portion  133  is sized to extend through the through-hole  115 . The end portion  133  has a retaining end  134  at a distal end thereof. The washer  101  and the anti-frictional element  103  of securing structure  10  may be placed around the retaining end  134 . A sectional configuration of the retaining end  134  corresponds with the square hole  1011 , in which, the retaining end  134  may be locked into the square hole  1011  of the washer  101 . The screw portion  131  is located between the end portion  133  and the shaft portion  132 . The screw portion  131  is substantially cylindrical, and partially defines a thread  1311  thereon. The thread  1311  is a raised helical or spiral rib/ridge defined on the surface of shaft  13 . A diameter of the shaft portion  132  is smaller than that of the first spring  12 . The shaft portion  132  is cylindrical in shape, and has a flat surface at a free end thereof forming a flat portion  135 . 
     Referring to  FIG. 4 , the cam  14  includes an outer surface  143 , an inner surface  140  and an axis hole  141 . The diameter of the outer surface  143  substantially equals that of the sleeve  11 . The outer surface  143  includes two symmetric latching blocks  144  slidably received in the trough  114  of the sleeve  11  so the cam  14  may be non-rotatably received in the sleeve  11 . A diameter of the axis hole  141  is substantially equal to that of the screw portion  131  of the shaft  13 . The inner surface  140  includes a protrusion  142  adjacent to one end of the cam  14 . The protrusion  142  has a substantially prismatic shape and configured for interacting with the thread  1311  of the screw portion  131  so that the protrusion  142  may slide and rotate along the thread  1311  when shaft  13  is rotated. One end of the cam  14  has a cam surface  146 , and the other end thereof has an end surface  145 . The cam surface  146  includes two symmetric peaks  1461  and two symmetric valleys  1464 . A vertical surface  1462 , a buffering surface  1463 , and a slope surface  1465  connected to each other are formed between the two valleys  1464 . The two peaks  1461  are respectively formed between the buffering surface  1463  and the vertical surface  1462 . 
     Referring to  FIG. 5 , the follower  15  includes a cylindrical outer wall  150 , a first end  153  and a second end  157 . Two extending walls  154  extend away from the first end  153  of the follower  15 . Two notches  155  are defined between the extending walls  154 . The outer wall  150  defines two inclined slots  156  respectively corresponding to a notch  155 . The inclined slot  156  with the notch  155  cooperatively define a first reverse groove  159 . The second end  157  of the follower  15  has a latching cam surface  152 . The latching cam surface  152  includes two symmetric peaks  1521  and two symmetric valleys  1524 , and engages with the cam surface  146  of the cam  14 . A slant surface  1525 , a buffering surface  1523 , and a perpendicular surface  1535  are defined between two valleys  1533 . 
     The second spring  16  is substantially cylindrical and sized to be placed around the shaft  13 . 
     The control member  17  has a disk-shaped body portion  171 . Two opposite wedge walls  172  extend from a peripheral wall of the body  171 , thereby forming two opposite second reverse slots  173  at one side thereof. Each wedge wall  172  may be received in a corresponding first revere slot  159  of the follower  15 , and each extending wall  154  of the follower  15  may be received in a corresponding second reverse slot  173 . A central hole  174  is defined in the body portion  171  so that the shaft portion  132  may pass through the central hole  174  of the control member  17 . 
     Referring to  FIGS. 6 and 7 , the fixing seat  18  has an outer circumferential wall  181 , an inner circumferential wall  182  and two open ends (partially shown). The outside circumferential wall  181  defines four fixing grooves  183  so that the fixing seat  18  can be fixedly retained in the cover section  52  of the foldable electronic device  50 . The outside circumferential wall  181  defines two guide cutouts  189 . Adjacent to each of the guide cutout  189 , two opposite ribs  187  are formed at one end of the fixing seat  18 . Two symmetric spaced arcuate blocks  184  are formed in the inner circumferential wall  182  and each engages a corresponding second reverse slot  173 . Each arcuate block  184  has an inner wall  1841 . A cylindrical connecting portion  185  is formed between the arcuate blocks  184 . Two insert holes  186  are defined between the inner circumferential wall  182  and the connecting portion  185 . The connecting portion  185  defines a deformed hole  1851  in a central area thereof. The shape and the size of the deformed hole  1851  correspond to the flat portion  137  of the shaft portion  132 . A step  1852  is formed at an outer circumferential wall of the connecting portion  185 . 
     The return spring  19  is substantially cylindrical. One end of the return spring  19  resists the step  1852  of the connecting portion  185 , and the other end resists the pressing element  20 . 
     The pressing element  20  includes a disk-shaped body  201 , and two opposite arms  203  extending from the body  201  along a longitudinal direction thereof. Two guide portions  204  extend from the body  201  along an axial direction thereof. Each guide portion  204  includes a clasp  2041  at a distal end thereof. The clasps  2041  may clamp to the rib  187  of the fixing seat  18  to prevent the pressing element  20  from separating from the fixing seat  18 . The arms  203  and the guide portions  204  cooperatively form a cylindrical receiving space  202 . The receiving space  202  is sized for receiving the return spring  19  therein. 
     In assembly, referring to  FIGS. 8 to 11 , the cam  14  is placed around the screw portion  131 , with the protrusion  142  of the cam  14  engaging with the thread  1311  of the shaft  13 . The cam surface  146  faces the flat portion  135 . 
     The follower  15  passes over the shaft portion  132  of the shaft  13 , with the latching cam surface  152  of the follower  15  engaging with the cam surface  146  of the cam  14 . The second spring  16  is placed around the shaft  13 , with one end of the second spring  16  resisting with one end of the follower  15 . Then, the central hole  174  of the control member  17  is placed around the shaft portion  132 . The wedge walls  172  of the control member  17  engage in the first reverse slots  159  of the follower  15  between the extending walls  154 , and the extending walls  154  of the follower  15  are then inserted into the second reverse slots  173  of the control member  17  to lock the control member  17  with the follower  15 . 
     The fixing seat  18  is then placed around the control member  17 . The flat portion  135  of the shaft portion  132  of the shaft  13  extends out from the deformed hole  1851  of the fixing seat  18 . The arcuate blocks  184  of the fixing seat  18  engage in the second reverse slots  173  of the control member  17 , thereby limiting the rotation of the control member  17  relative to the fixing seat  18 . 
     The return spring  19  is received in the receiving space  202 . Then, the pressing element  20  with the return spring  19  is disposed in the fixing seat  18 . The return spring  19  resists the step  1852  of the fixing seat  18 . At the same time, the guide portions  204  are pressed and inserted into the guide cutouts  189 . Accordingly, the arms  203  are received in the inserted hole  186  of the fixing seat  18 . After the guide portions  204  are released, the clasps  2041  clamp the ribs  187  of the fixing seat  18 . The return spring  19  has a predetermined elastic force. Accordingly, the above elements are fixed to the shaft  13 . 
     The first spring  12  is placed around the screw portion  131  of the shaft  13 . The above-mentioned assembled elements are received into the sleeve  11  along one end of the assembled elements with the first spring  12 . The latching blocks  144  of the cam  14  engage in the trough  114  of the sleeve  11 , and the retaining end  134  extends out from the partially-closed end of the sleeve  11 . Finally, the anti-friction element  103  is placed around the retaining end  134  of the shaft  13 , and the washer  101  is tightly locked on the retaining end  134 . The hinge assembly  100  is thus completely assembled. 
     To incorporate the self-contained component into a mobile phone during manufacturing, the sleeve  11  engages in a cavity (not shown) of the cover section  52  of the mobile phone  50 , and the fixing seat  18  connects with the body section  54  of the mobile phone  50 . When the cover section  52  of the mobile phone  50  is in a fully open position, the peaks  1461  of the cam  14  resist the valleys  1524  of the follower  15 . The protrusion  142  engages in the thread  1311 . The first spring  12  exerts a predetermined pressure on the cam  14  so that the cam  14  should rotate relative to the outer screw thread  1320  of the shaft  13 . However, the follower  15  and the control member  17  prevent the cam  14  from rotating. 
     In use, when the cover section  52  of the mobile phone  50  is being closed, the cover section  52  can be closed by hand by pushing the sleeve  11  to rotate relative to the body section  54 . The sleeve  11  further brings the cam  14  to rotate along the thread  1311  of the shaft  13 . Due to the control member  17  being locked into the arcuate blocks  184  of the fixing seat  18 , the control member  17  cannot rotate relative to the fixing seat  18 . Accordingly, the follower  14  does not rotate relative to the fixing seat  18 . When the cam  14  rotates, the protrusion  142  of the cam  14  break away from the thread  1311  of the shaft. The cam surface  146  of the cam  14  slides and rotates relative to the latching cam surface of the follower  15 . The cam  15  is then pushed towards the button  20 . When the peaks  1461  of the cam  14  slide to passes over the peaks  1521  of the follower  15  and stay on the buffering surface  1523 , the first spring  12  accumulates elastic potential energy. At that time, the cover section  52  becomes closed relative to the body section  54  of the mobile phone  50 . The protrusion  142  is spaced from the thread  1311  of the shaft  13 . 
     When a user wants to open the cover section  52  of the mobile phone  50  automatically, he/she may only hold the mobile phone  50  and press the pressing element  20  by one hand. In this process, the pressing element  20  moves along an axial direction of the shaft  13 , the arms  204  of the pressing element  20  then push the control member  17  to move away from the pressing element  20  in the axial direction of the shaft  13 . The control member  17  moves axially, compressing the second spring  16  towards the cam  14 . When the wedge walls  172  of the control member  17  break away from the limitation of the arcuate blocks  184  of the fixing seat  18 , the cam  14  then rotates relative to the shaft  13  along the thread  1311  under elastic energy of the first spring  12 . After the pressing element  20  is released, the return spring  19  allows the pressing element  20  return to an original state. 
     When the cam  14  rotates, the peaks  1461  of the cam surface  146  slide downward from the buffering surface  1523  of the follower  15  until the peaks  1461  contact with the valleys  1524  of the follower  15 . The gap between the protrusion  142  and the thread  1311  is eliminated. Accordingly, the protrusion  142  is engaged with the thread  1311  of the shaft  13 . When the cam  14  rotates and slides relative to the shaft  13 , the follower  15 , the second spring  16  and the control member  17  together move and rotate. Furthermore, the sleeve  11  rotates with the cam  14  so that the cover section  52  of the mobile phone  50  is opened. Whilst the sleeve  11  rotates relative to the shaft  13 , the anti-friction element  103  directly contacts the washer  101 . The anti-friction element  102  may greatly decrease the abrasion between the sleeve  11  and the washer  101 . 
     The cam  14  stops rotating when the cover section  52  of the mobile phone  50  is completely opened. The elastic potential energy of the second spring  16  then pushes the control member  17  to move toward the pressing element  20 . Accordingly, the wedge walls  172  of the control member  17  are locked between the blocks  184  of the fixing seat  18 . The hinge assembly  100  may be opened manually. The principles of the manual opening process are basically the same as the manual closing process. 
     In an alternative embodiment, the first spring  12 , the second spring  16  and the return spring  19  may be replaced by other elastic elements such as an elastic sponge. 
     Understandably, the thread number of the shaft may be more than two. Accordingly, the number of the protrusion in the cam corresponds to the thread number. If the thread of the screw portion is a single thread, the protrusion of the cam may be two. The axial and radial distance between the protrusions, beneficially, corresponds to the thread distance of the shaft so that the two protrusions may engage in the thread of the shaft. 
     As described above, the present embodiment provides a hinge assembly  100  for use with various portable devices, beyond the mobile phone illustrated, and/or with other devices needing a hinge assembly that selectably facilitates the achievement of fully open and fully closed positions. 
     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.