Patent Publication Number: US-6698138-B1

Title: Adjustable pulley assembly for a suspended door

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an adjustable pulley assembly for a suspended door such as an aluminum door, stainless steel door, wooden door, glass door, or automatic door. 
     2. Description of the Related Art 
     A suspended door is generally used in public places that require frequent opening and closing of the door. An advantage of the suspended door is that it is not necessary to install a track or guide groove on the floor for the door, which provides an aesthetically pleasing effect and allows easy cleaning of the floor. Another advantage of the suspended door is that it is easy to design the drive device for the suspended door. In particular, easy control of forward/rearward movement of the suspended door can be easily achieved through the use of a motor mounted to a track above the door frame and control circuits. Hence, electric doors used in public places generally employ suspended doors. 
     Conventionally, a set of pulley assembly is mounted to each of a left side and a right side of a top portion of a suspended door so as to hang the door on the track. After installation of the suspended door, it is necessary to adjust the position of the suspended door in the left/right direction and/or the vertical direction. The suspended door, which weights up to 100 kg, is lifted by labor for proceeding with adjustment of the position of the axle of the pulley. Another solution is detaching the suspended door, proceeding with required adjustment, and then reinstalling the suspended door. Yet it is troublesome and causes a waste of time and labor while the adjustment may not be precise. 
     SUMMARY OF THE INVENTION 
     An object of the present invention is to provide an adjustable pulley assembly for a suspended door that allows easy adjustment of the position of the suspended door in the left/right direction and/or vertical direction. 
     Another object of the present invention is to provide an adjustable pulley assembly for a suspended door that is suitable for use with a belt assembly and an anti-disengagement arrangement. 
     A further object of the present invention is to provide an adjustable pulley assembly for a suspended door that is reliable, durable, and force-saving to operation. 
     An adjustable pulley assembly for a suspended door in accordance with the present invention includes a fixing plate securely mounted on top of an upper frame of a suspended door, an adjusting seat mounted to the fixing plate, a pulley seat securely attached to the adjusting seat to move therewith, a pulley attached to the pulley seat, and an adjusting bolt. 
     The adjusting seat includes a first vertical plate having an upper end and a lower end, a top plate extending from the upper end of the first vertical plate along a direction transverse to the first vertical plate, and a bottom plate extending from the bottom end of the first vertical plate along a direction opposite to the extending direction of the top plate. The first vertical plate includes a vertical slot, and the top plate includes a screw hole. 
     The pulley seat includes a second vertical plate and a top plate extending from an upper end of the second vertical plate along a direction transverse to the second vertical plate. The second vertical plate has a screw hole, and the top plate of the pulley seat has a hole aligned with the screw hole of the top plate of the adjusting seat. 
     The pulley includes a bearing mounted therein. An axle extends through the pulley and extends through the screw hole of the vertical plate of the pulley seat and the vertical slot of the adjusting seat, with a nut engaged on a distal end of the axle. The pulley is mounted on a guide rail of a track along which the suspended door moves. The adjusting bolt extends through the hole of the top plate of the pulley seat and the screw hole of the top plate of the adjusting seat. 
     When the adjusting bolt is turned, the vertical slot of the first vertical plate of the adjusting seat allows relative movement between the top plate of the pulley seat and the top plate of the adjusting seat in the vertical direction, thereby changing a distance between the top plate of the pulley seat and the top plate of the adjusting seat. 
     Other objects, advantages, and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of an adjustable pulley assembly for a suspended door in accordance with the present invention. 
     FIG. 2 is an exploded perspective view of the adjustable pulley assembly for a suspended door in accordance with the present invention. 
     FIG. 3 is a sectional view illustrating use of adjustable pulley assembly for a suspended door in accordance with the present invention. 
     FIG. 4 is a sectional view similar to FIG. 3, illustrating adjustment of the position of the suspended door in the vertical direction. 
     FIG. 5 is a side view of the arrangement in FIG.  4 . 
     FIG. 6 is a sectional view similar to FIG. 4, illustrating use of the adjustable pulley assembly with a narrower suspended door. 
     FIG. 7 is an exploded perspective view of a belt frame used with the adjustable pulley assembly in accordance with the present invention. 
     FIG. 8 is a sectional view illustrating mounting of the belt frame to the adjustable pulley assembly for an electric suspended door. 
     FIG. 9 is a sectional view illustrating another mounting of the belt frame to the adjustable pulley assembly for an electric suspended door. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIGS. 1 through 3, an adjustable pulley assembly in accordance with the present invention is mounted to an end (e.g., left end or right end) of a top of a suspended door  10  and generally comprises a fixing plate  20 , an adjusting seat  30 , a pulley seat  40 , a pulley  50 , and an adjusting bolt  37 . It is noted that a suspended door  10  generally has two pulley assemblies attached to the top thereof to provide a uniform, balanced support for the suspended door  10 . Nevertheless, a single pulley assembly having a sufficiently strong support can be used without departing the scope of the invention. The position of a suspended door  10  to which the adjustable pulley assembly is mounted can be adjusted in a front/rear direction and/or vertical direction, which will be described later. 
     The fixing plate  20  includes two ends each having holes  23  and an elongated hole  25 . Bolts  24  (FIG. 3) are selectively extended through the holes  23  or the elongated holes  25  for mounting the fixing plate  20  to a top of an upper frame of a wider suspended door  10  (FIG. 3) or of a narrower suspended door  11  (FIG.  6 ). Further, the fixing plate  20  includes two elevated sections  21  between the ends thereof, with each elevated section  21  having a screw hole  22 . The elevated sections  21  are spaced apart by an intermediate portion (not labeled) of the fixing plate  20 . 
     The adjusting seat  30  is a substantially vertical plate  38  having two vertically spaced vertical slots  30  and  330 . The adjusting seat  30  further has a top plate  31  extending from an upper end of the vertical plate  38  along a direction transverse (preferably perpendicular) to the vertical direction. A screw hole  34  is defined in the top plate  31 . The adjusting seat  30  further has a bottom plate  32  extending from a lower end of the vertical plate  38  along a direction transverse (preferably perpendicular) to the vertical direction and opposite to the extending direction of the top plate  31 . An elongated hole  35  is defined in each of two ends of the bottom plate  32 . A bolt  36  is extended through each elongated hole  35  of the bottom plate  32  and then engaged with the screw hole  22  of an associated elevated section  21  of the fixing plate  20 , allowing adjustment of the position of the suspended door  10  in the front/rear direction (i.e., the moving direction of the suspended door  10 ). The elevated sections  21  of the fixing plate  20  provide spaces for receiving the heads (not labeled) of the bolts  24  and the threaded shank (not labeled) of the bolts  36 . 
     The pulley seat  40  includes a vertical plate  49  and a top plate  41  extending from an upper end of the vertical plate  49  along a direction transverse (preferably perpendicular) to the vertical direction. The top plate  41  of the pulley seat  40  abuts against on top of the top plate  31  of the adjusting seat  30 , with a hole  44  in the top plate  41  aligned with the screw hole  34  of the adjusting seat  30 . The vertical plate  49  has an upper screw hole  42  and a lower screw hole  43  in an intermediate portion thereof. The screw holes  42  and  43  are respectively aligned with the vertical slots  30  and  330  of the vertical plate  38  of the adjusting seat  30 . 
     The pulley  50  includes an annular groove  54  in an outer periphery thereof and a bore  56  that receives a bearing  51  therein. As illustrated in FIG. 3, the pulley is attached to the vertical plate  49  of the pulley seat  40  by means of extending an axle  52  through the bearing  51 , the upper screw hole  42  of the vertical plate  49  of the pulley seat  40 , and the upper vertical slot  33  of the vertical plate  38  of the adjusting seat  30 . A nut  53  is engaged with a distal portion of a threaded shank (not labeled) of the axle  52  to prevent disengagement. Further, a collar  55  is mounted around the axle  52  and located between the vertical plate  49  of the pulley seat  40  and an end face (not labeled) of the bearing  51 . Further, an adjusting bolt  37  is extended through the screw hole  34  of the top plate  31  of the adjusting seat  30  and the hole  44  of the top plate  41  of the pulley seat  40 . Further, a bolt  45  is extended through the lower screw hole  43  of the vertical plate  49  of the pulley seat  40  and the lower vertical slot  330  of the vertical plate  38  of the adjusting seat  30 . The bolt  45  has a distal, protruded portion located below the pulley  50  for preventing the adjustable pulley assembly from being disengaged from a track  60  for the suspended door  10 . Still referring to FIG. 3, the track  60  is fixed to a wall (not shown) of a building (not shown) and has a guide rail  61  for engaging with the annular groove  54  of the pulley  50 . Thus, the pulley  50  and the whole adjustable pulley assembly are movable along the guide rail  61  for opening/closing the suspended door  10  that is fixed to the fixing plate  20 . Preferably, a bottom wall delimiting the annular groove  54  is smooth and wide and designed complimentary to a top face of the guide rail  61  to thereby increase the area for supporting the weight of the suspended door  10  and to thereby provide a durable structure. Since the axle  52  for the pulley  50  is directly extended through the upper screw hole  42  of the pulley seat  40  and the nut  53 , since the bolt  45  is extended through the lower vertical slot  330  of the adjusting seat  30  and the lower screw hole  43  of the pulley seat  40 , and since the adjusting bolt  37  is extended through the hole  44  of the pulley seat  40  and the screw hole  34  of the adjusting seat  30 , the adjustable pulley assembly is improved in strength and more durable. 
     FIGS. 4 and 5 illustrate adjustment operation of the adjustable pulley assembly in accordance with the present invention. If adjustment is required after installation of the suspended door  10 , the nut  53  engaged on the distal end of the threaded portion of the axle  52  is loosened and the bolt  45  is loosened to allow direct turning of the adjusting bolt  37 . Due to provision of the vertical slots  33  and  330 , the vertical position of the left side (or the right side) of the suspended door  10  can be directly adjusted through turning of the adjusting bolt  37 . Namely, the upper vertical slot  33  of the vertical plate  30  of the adjusting seat  30  allows relative movement between the top plate  41  of the pulley seat  40  and the top plate  31  of the adjusting seat  30  in the vertical direction, thereby changing a distance between the top plate  41  of the pulley seat  40  and the top plate  31  of the adjusting seat  30 . 
     A distance between a central axis of the axle  52  and a central axis of the bolt  45  is so determined (basing on a diameter of the pulley  50  and the dimension of the guide rail  61 ) that the distal, protruded end of the bolt  45  is located below and spaced from the guide rail  61  by an appropriate distance. Thus, the suspended door  10  is prevented from being disengaged from the guide rail  61  when the suspended door  10  is subject to an external force. In an embodiment of the invention, the distal, protruded end of the bolt  45  is in the form of a smooth round shank  46  having a reduced diameter. 
     FIG. 7 is an exploded perspective view of a belt frame used with the adjustable pulley assembly in accordance with the present invention. FIG. 8 is a sectional view illustrating mounting of the belt frame to the adjustable pulley assembly for an electric suspended door. FIG. 9 is a sectional view illustrating another mounting of the belt frame to the adjustable pulley assembly for an electric suspended door. 
     As illustrated in FIG. 2, the vertical plate  49  of the pulley seat  40  has a pair of vertically spaced apart holes  48  in each of two sides thereof and a screw hole  47  between each pair of holes  48 . As illustrated in FIG. 7, the belt frame  70  includes a vertical section  78  having two round protrusions  77  on a lower portion thereof, with a hole  74  defined between the protrusions  77 . The protrusions  77  are engaged with the holes  48  on one of the sides of the vertical plate  49  of the pulley seat  40 , and a bolt  76  is extended through the hole  74  of the belt frame  70  and the associated screw hole  47  of the vertical plate  49  of the pulley seat  40 . Thus, the belt frame  70  is fixed to the pulley seat  40  to move therewith. A top extension plate  71  extends from an upper end of the vertical section  78  along a direction perpendicular to the vertical direction and has a screw hole  75 . A bottom extension plate  72  extends from the lower portion of the vertical section  78  along a direction perpendicular to the vertical direction and has a screw hole  75 . 
     A fixing member  80  is provided for mounting an endless belt  90  for transmission. As illustrated in FIG. 7, the fixing member  80  is substantially U-shaped and includes an elongated hole  82  in an intermediate portion thereof, a guide block  84  on an end of the intermediate portion thereof, and a recessed portion  81  located in a position opposite to the guide block  84 . The endless belt  90  is extended through and securely held by the recessed portion  81  of the fixing member  80 . As illustrated in FIG. 8, a bolt  83  is extended through the elongated hole  82  of the fixing member  80  and the screw hole  75  of the top extension plate  71 , thereby securely attaching the adjustable pulley assembly to an upper section of the endless belt  90  for transmission. FIG. 9 illustrates an alternative arrangement of the fixing member  80 , wherein the fixing member  80  is attached to the lower extension plate  72  of the belt frame  70 , thereby securely attaching the adjustable pulley assembly to the lower section of the endless belt  90 . 
     The vertical section  78  of the belt frame  70  includes an upper guide opening  73  and a lower guide opening  73  for selectively engaging with the guide block  84  of the fixing member  80 , thereby allowing adjustment of the position of the fixing member  80  in the front/rear direction. 
     It is noted that the adjustable pulley assembly in accordance with the present invention allows the vertical position of the left side and the right side of the suspended door  10 ,  11  to be quickly adjusted and the adjustment is force-saving. Further, the adjustable pulley assembly in accordance with the present invention provides a reliable and durable structure and can be used with a belt frame. Further, the adjustable pulley assembly in accordance with the present invention prevents the suspended door  10 ,  11  from being disengaged from the guide rail  61 . 
     Although the invention has been explained in relation to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the scope of the invention as hereinafter claimed.