Patent Publication Number: US-6658694-B2

Title: Hinge device with a returning member for automatically closing an open door

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a hinge device, more particularly to a hinge device with a returning member for automatically closing an open door. 
     2. Description of the Related Art 
     A conventional hinge device generally includes a stationary hinge member that is adapted to be mounted on a door frame, and a rotatable hinge member that is adapted to be mounted on a door and that is pivoted to the stationary hinge member so as to permit rotation of the door relative to the door frame between open and closed positions. 
     One drawback of the aforesaid conventional hinge device resides in that the door needs to be moved manually from the open position to the closed position. 
     An improved hinge device has been proposed in order to overcome the aforesaid drawback, and includes a biasing member or a hydraulic device interposed between the stationary and rotatable hinge members for automatically closing an open door. However, the biasing member generally closes the door so swiftly such that banging of the door relative to the door frame may result. The hydraulic device employed in the improved hinge device may reduce the effect of banging, but includes too many components that complicate assembly and mass production of the same. 
     SUMMARY OF THE INVENTION 
     The object of this invention is to provide a hinge device with a returning member for automatically closing an open door and that is capable of overcoming the aforesaid drawbacks of the conventional hinge devices. 
     Accordingly, a hinge device of the present invention includes a stationary hinge member, a rotatable hinge member, a cam mechanism, and a biasing member. The rotatable hinge member is pivoted to the stationary hinge member so as to rotate about a vertical axis between open and closed positions. The cam mechanism includes a rotatable cam element that is coupled to the rotatable hinge member so as to rotate about the vertical axis together with the rotatable hinge member and that is formed with a first cam face, and a slidable cam element that is formed with a second cam face associated with the first cam face and that is movable in an axial direction along the vertical axis. The second cam face moves away from the first cam face when the slidable cam element is cammed by the rotatable cam element upon rotation of the rotatable hinge member from the closed position to the open position by an external force applied on the rotatable hinge member. The biasing member is connected to the slidable cam element so as to accumulate a returning force when the second cam face moves away from the first cam face and so as to urge the second cam face to move toward the first cam face when the external force ceases to be applied on the rotatable hinge member, thereby returning the rotatable hinge member from the open position to the closed position. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and other features and advantages of this invention will become apparent in the following detailed description of the preferred embodiment of this invention, with reference to the accompanying drawings, in which: 
     FIG. 1 is an exploded perspective view of a preferred embodiment of a hinge device according to the present invention; 
     FIG. 2 is a fragmentary sectional view of the preferred embodiment, illustrating connecting relationship between rotatable and slidable cam elements employed therein when the preferred embodiment is disposed at a closed position; 
     FIG. 3 is a fragmentary sectional view of the preferred embodiment, illustrating the connecting relationship between the rotatable and slidable cam elements employed therein when the preferred embodiment is disposed at an open position; 
     FIG. 4 illustrates how two restricting studs of the rotatable cam element extend into two restricted slots in a guide tube in order to provide a retarding action during closing movement of the preferred embodiment so as to avoid a banging action; 
     FIG. 5 illustrates movement of the restricting studs of the rotatable cam element along the restricting slots for providing the retarding action during closing movement of the preferred embodiment; and 
     FIG. 6 illustrates how a door is mounted on a door frame by using two hinge devices of the preferred embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIGS. 1 to  5 , the preferred embodiment of a hinge device according to the present invention is shown to include a stationary hinge member  4 , a rotatable hinge member  3 , and a returning member consisting of a cam mechanism and a biasing member  75 . 
     As illustrated, the rotatable hinge member  3  is pivoted to the stationary hinge member  4  so as to rotate about a vertical axis between open and closed positions, as best shown in FIGS. 2 and 3, respectively. 
     The cam mechanism includes a rotatable cam element  66  that is coupled to the rotatable hinge member  3  so as to rotate about the vertical axis together with the rotatable hinge member  3  and that is formed with a first cam face  665 , and a slidable cam element  77  that is formed with a second cam face  775  associated with the first cam face  665  and that is movable in an axial direction along the vertical axis. When an external force is applied on the rotatable hinge member  3  so as to move the same from the closed position of FIG. 2 to the open position of FIG. 3, the second cam face  775  of the slideable cam element  77  moves away from the first cam face  665  because the slidable cam element  77  is cammed by the rotatable cam element  66 . 
     The biasing member  75 , such a compression spring, is connected to the slidable cam element  77  in such a manner so as to accumulate a returning force when the second cam face  775  moves away from the first cam face  665  and so as to urge the second cam face  775  toward the first cam face  665  when the external force ceases to be applied on the rotatable hinge member  3 , thereby returning the rotatable hinge member  3  from the open position to the closed position. 
     The stationary hinge member  4  preferably includes a stationary leaf  41  adapted to be mounted on a door frame (not shown), and a hollow tubular member  42  fixed to the stationary leaf  41  and within which the rotatable cam element  66  and the slidable cam element  77  are received one above the other. 
     The rotatable cam element  66  includes a cylindrical portion  661  that extends in the axial direction, and that has a top end defining a top abutment face  668 . The top abutment face  668  extends in a transverse direction relative to the vertical axis. The cylindrical portion  661  is further formed with two opposing V-shaped notches  666  which extend inclinedly and downwardly from the top abutment face  668  and which cooperatively define the first cam face  665 . 
     The slidable cam element  77  includes a cylindrical portion  771  that extends in the axial direction, and that is disposed above the cylindrical portion  661  of the rotatable cam element  66 . The cylindrical portion  771  has a bottom abutment face  778  extending in the transverse direction. The cylindrical portion  771  of the slidable cam element  77  is formed with two opposing V-shaped notches  777  which extend inclinedly and upwardly from the bottom abutment face  778  and which cooperatively define the second cam face  775 . The top and bottom abutment faces  668 ,  778  of the rotatable and slidable cam elements  66 ,  77  abut and push against each other by the returning force of the biasing member  75  when the rotatable hinge member  3  rotates from the open position to a stationary position, thereby permitting positioning of the rotatable hinge member  3  stationarily relative to the stationary hinge member  4 . 
     A guide tube  51  is mounted securely within the tubular member  42  via a fastener pin  55  to define an element-receiving chamber  510 , within which the rotatable and slidable cam elements  66 ,  77  are received. The guide tube  51  has a top end  511 , and is formed with two opposing guide grooves  53  that extend from the top end  511  and that communicate with the element-receiving chamber  510 . The cylindrical portion  771  of the slidable cam element  77  has two radially and outwardly extending guide studs  73  that respectively project into the guide grooves  53  so as to ensure sliding movement of the slidable cam element  66  in the axial direction. 
     A rotatable connecting member  64  is disposed in the tubular member  42  below the rotatable cam element  66 , and includes a cylindrical piece  641  that has top and bottom ends, and a top annular flange  643  projecting radially and outwardly from the top end of the cylindrical piece  64  and abutting against a bottom end of the cylindrical portion  661  of the rotatable cam element  66 . The cylindrical piece  641  is formed with a non-circular spring-mounting recess  645  that extends inwardly from the top end of the cylindrical piece  641  in the axial direction. An urging member  65 , such as a biasing spring, is mounted in the spring-mounting recess  645 . The rotatable cam element  66  further includes a non-circular reduced portion  662  that projects axially from the bottom end of the cylindrical portion  661  and into the spring-mounting recess  645  to engage the same so as to permit co-rotation of the connecting member  64  with the rotatable cam element  66 , and to abut against the urging member  65  so as to provide a buffering action for counteracting the returning force of the biasing member  75  when the rotatable hinge member  3  is moved from the open position to the closed position. Under this condition, banging of the door relative to the door frame can be avoided during the door closing operation. 
     The guide tube  51  has a bottom end  512 , and is further formed with two opposing arcuate restricting slots  54  that extend from the bottom end  512  in the axial direction. The rotatable cam element  66  further includes an annular flange  663  that extends radially and outwardly from the bottom end of the cylindrical portion  661  and that is exposed from the bottom end  512  of the guide tube  51 , and a pair of opposing restricting studs  664  that project from the annular flange  663  toward the bottom end  512  of the guide tube  51  in such a manner that the restricting studs  664  are offset from the restricting slots  54  when the rotatable hinge member  3  is disposed at the closed position and that the restricting studs  664  are respectively aligned with and are urged by the urging member  65  to extend into the restricting slots  54  when the rotatable hinge member  3  is disposed at either of the open and stationary positions. Each of the studs  664  is positioned at one end of a respective one of the restricting slots  54  (see FIG. 5) when the rotatable hinge member  3  is positioned at the stationary position, and is moved from said one end to the other end of the respective one of the restricting slots  54  when the rotatable hinge member  3  is moved from the stationary position toward the closed position. During this time, the top and bottom abutment faces  668 ,  778  disengage from each other to permit rotation of the rotatable cam element  66 , which is stopped, when the restricting studs  664  are moved to the other end of the respective one of the restricting slots  54 , and which starts moving axially until the restricting studs  664  disengage the restricting slots  54 , thereby permitting restoring of the rotatable cam element  66  until the returning force is fully counteracted by the urging member  65  so as to position the rotatable hinge member  3  at the closed position. 
     Preferably, the rotatable hinge member  3  includes a rotatable leaf  31  adapted to be fixed on the door, and vertically spaced apart annular upper and lower couplers  32 ,  33  that are fixed to the rotatable leaf  31  and that sandwich the tubular member  42  of the stationary hinge member  4  therebetween. The lower coupler  33  is formed with a non-circular mounting hole  331 . The bottom end  642  of the cylindrical piece  641  is formed with an inner threaded hole  644  that is in spatial communication with the non-circular spring-mounting recess  645 . The bottom end  642  of the cylindrical piece  641  is non-circular in cross section, and extends into and engages the mounting hole  331  of the lower coupler  33  so as to permit co-rotation of the rotatable hinge member  3  and the rotatable cam element  66  via the rotatable connecting member  64 . A screw bolt  68  is inserted threadedly from an exterior of the lower coupler  33  to engage the inner threaded hole  644  of the cylindrical piece  641  so as to retain the bottom end  642  of the cylindrical piece  641  in the mounting hole  331  of the lower coupler  33 . 
     Preferably, the tubular member  42  in this embodiment has top and bottom inner threaded ends  422 ,  423 . A pair of upper bearing units  71 ,  72  sandwich opposite sides of the upper coupler  32 . A pair of lower bearing units  62 ,  63  is disposed in the tubular member  42  between the top annular flange  643  of the rotatable connecting member  64  and the lower coupler  33 . A lower bearing-positioning member  69  is sandwiched between the lower bearing units  62 ,  63 , and has a bottom flange  691  sandwiched between the bottom inner threaded end  423  of the tubular member  42  and one of the lower bearing units  62  which abuts against the lower coupler  33 , and a reduced threaded portion  692  that projects from the bottom flange  691  and that threadedly engages the bottom inner threaded end  423  of the tubular member  42  in such a manner that the reduced threaded portion  692  cooperates with the top annular flange  643  of the cylindrical piece  641  to sandwich the other one of the lower bearing units  63  therebetween. The screw bolt  68  extends through the lower bearing-positioning member  69  so as to facilitate rotation of the rotatable hinge member  3  relative to the stationary hinge member  4 . 
     The urging member  65  abuts against the reduced portion  662  of the rotatable cam element  66  and the screw bolt  68  in such a manner that tightening and loosening of the screw bolt  68  relative to the cylindrical piece  641  results in adjustment of the buffering action for counteracting the returning force of the biasing member  75 . 
     An upper bearing-positioning member  79 , in the form of a hollow tube, is mounted threadedly on the top inner threaded end  422  of the tubular member  42 , and has a radially and outwardly extending bearing-retention flange  791 . The upper bearing units  71 , 72  are sleeved around the upper bearing-positioning member  79  in such a manner that the bearing-retention flange  791  cooperates with the upper coupler  32  to sandwich one of the upper bearing units  71  therebetween, and that the top inner threaded end  422  of the tubular member  42  cooperates with the upper coupler  32  to sandwich the other one of the upper bearing units  72  therebetween. 
     Preferably, the biasing member  75  includes a hydraulic cylinder  751  mounted securely in the tubular member  42  via a fastener pin  755 , and extending into the upper bearing-positioning member  79  so as to enhance positioning of the hydraulic cylinder  751  in the tubular member  42 . The hydraulic cylinder  751  has a piston  752  secured to a top end of the slidable cam element  77  so as to be movable in the axial direction for permitting accumulation of the returning force and restoration of the rotatable hinge member  3  to the closed position from the open position, and an adjustable knob  753  that projects from one end of the hydraulic cylinder  751  which is opposite to the piston  752  and that is movable inward and outward of the hydraulic cylinder  751  for adjusting an inner pressure inside the hydraulic cylinder  751 . An adjustment bolt  76  is mounted threadedly in the upper bearing-positioning member  79 , and contacts the adjustable knob  753  such that movement of the adjustment bolt  76  in the upper bearing-positioning member  79  changes the magnitude of the returning force to be applied to the slidable cam element  77 . 
     FIG. 6 shows how a door  82  is mounted on a door frame  81  by using two hinge devices of the preferred embodiment. 
     With this invention thus explained, it is apparent that numerous modifications and variations can be made without departing from the scope and spirit of this invention. It is therefore intended that this invention be limited only as indicated by the appended claims.