Patent Publication Number: US-2005139563-A1

Title: device and method for lifting objects in a limited headroom area

Description:
BACKGROUND  
      1.) Field of Invention  
      This invention relates to improvements for lifting and handling objects, such as bulk bags, in limited headroom areas.  
      2.) Description of Related Art  
      As more and more bulk bag applications (and other types of processes that involve lifting and handling objects of varying height) are designed and installed for a wide variety of lifting applications, the need for improvements in the handling of raw materials are surely to result. One of the more vexing problems has been in finding a simple, economical and off-the-shelf type of hoist assembly that can be used for low headroom applications. This invention allows the use a standard hoist to be used for low headroom applications.  
     SUMMARY  
      It is the object of the invention to locate the hoist to the side (and out of the way) of the object being lifted between the end of its chain and the I-Beam that the hoist is located on.  
      Another object of the invention is provide a simple hoist &amp; frame assembly that will allow an existing, standard type of hoist arrangement to be easily and inexpensively be reconfigured for low headroom applications.  
      Another object of the invention is to provide a method to gain greater space between an object be lifted under an I-Beam structure and the platform that it must raise to or platform that it must rest on.  
      Yet another object of the invention is to secure the hoist between two I-Beams. 
    
    
     BRIEF DESCRIPTION OF DRAWINGS  
       FIG. 1  is a detailed, side view of a bulk bag unloader with the hoist moved to the side so that it is not between the I-beam and object being lifted.  
       FIG. 2  is a detailed, side view of a bulk bag unloader using a side mounted hoist cart assembly to lift a bulk bag off of the floor and onto the unloader for discharging.  
       FIG. 3  is a detailed, side view of a bulk bag unloader using a side mounted hoist cart assembly to lift a bulk bag to its maximum height under the unloader&#39;s I-Beam.  
       FIG. 4  is a detailed, side view of a bulk bag unloader using a side mounted hoist cart assembly with a bulk bag moved laterally along the I-Beam to a location over the unloader&#39;s support tray.  
       FIG. 5  is a detailed, side view of a bulk bag unloader using a side mounted hoist cart assembly with a bulk bag lowered onto the unloader&#39;s support tray.  
       FIG. 6  is a detailed, side view of a bulk bag unloader with the hoist moved to the side so that it is not between the I-Beam and object being lifted.  
       FIG. 7  is a detailed, side view of a hoist carriage assembly and components whereby the hoist is located off to the side and clear of the object being lifted.  
       FIG. 8  is a side view of a bulk bag unloader using an inverted bag lift frame with a standard hoist and trolley assembly.  
       FIG. 9  is a detailed, front view of a hoist frame structure that utilizes two I-Beams with a hoist carriage and hoist placed between them that is equipped with a trolley assembly for low headroom applications.  
       FIG. 10  is a detailed, side view of a hoist frame that utilizes a twin I-Beam configuration and low profile hoist and carriage assembly.  
       FIG. 11  is a detailed front view of a standard hoist and trolley configuration that is equipped with an inverted bag lift frame.  
       FIG. 12  is a top view of an adjustable bag lift frame used for lifting bulk bags.  
       FIG. 13  is a detailed front view of the right half of a bulk bag attached to an inverted bag lift frame using a snap ring assembly.  
       FIG. 14  is a detailed front view of bag lift frame that is secured to the chain of hoist on the trolley carriage  32 . 
    
    
     
       
         
           
               
            
               
                   
               
               
                   
               
               
                 TABLE OF REFERENCE NUMBERS 
               
               
                 Definition List 1 
               
            
           
           
               
               
            
               
                 Term 
                 Definition 
               
               
                   
               
            
           
           
               
               
            
               
                 20 
                 Unloader Frame 
               
               
                 21 
                 Top Frame Support 
               
               
                 22 
                 Corner Post(s) 
               
               
                 23 
                 I-Beam 
               
               
                 24 
                 Trolley Assembly 
               
               
                 25 
                 Hoist 
               
               
                 26 
                 Chain 
               
               
                 27 
                 I-Beam Brackets 
               
               
                 28 
                 Bag Frame 
               
               
                 29 
                 Bag 
               
               
                 30 
                 Chain Bag 
               
               
                 31 
                 Trolley Motor 
               
               
                 32 
                 Hoist Cart 
               
               
                 33 
                 Wheel(s) 
               
               
                 34 
                 Hoist Frame 
               
               
                 35 
                 Hoist Anchor Pin 
               
               
                 36 
                 Hoist Frame Flange 
               
               
                 37 
                 Chain Wheel 
               
               
                 38 
                 Limit Switch 
               
               
                 39 
                 Chain Hook/Support Bracket 
               
               
                 40 
                 Chain Wheel(s) 
               
               
                 41 
                 Proximity Switch Bracket 
               
               
                 42 
                 Proximity Switch 
               
               
                 43 
                 Bag Frame End Flange(s) 
               
               
                 44 
                 End Flange Hole(s) 
               
               
                 45 
                 Posts 
               
               
                 46 
                 Lock Pin(s) 
               
               
                 47 
                 Bracing Supports 
               
               
                 48 
                 Snap Ring(s) 
               
               
                 50 
                 Floor 
               
               
                 85 
                 Support Tray 
               
               
                 86 
                 Cross Beam Support(s) 
               
               
                   
               
            
           
         
       
     
     DETAILED DESCRIPTION OF DRAWINGS  
       FIG. 1  is a side view of bulk bag unloader  20  with I-Beam  23  secured to top frame support  21 . I-Beam  23  may be permanently welded to unloader frame  20  or bolted to top frame support  21  by using I-Beam brackets  27   a ,  27   b ,  27   c  and  27   d . By welding I-Beam brackets  27   a  and  27   c  to top frame support  21  and I-Beam brackets  27   b  and  27   d  to I-Beam  23 , I-Beam  23  may be secured to top frame  21  when I-Beam brackets  27   a  and  27   b  and I-Beam brackets  27   c  and  27   d  are bolted together respectively. Trolley assembly  24 , which typically holds hoist  25  via anchor pin  37   b , is mounted to I-beam  23  in the same manner as for normal hoist operation. Hoist cart  32  comes complete as a single unit with hoist frame  34 , hoist frame flange  36 , hoist anchor bracket  35  and wheel(s)  33   c  (and  33   d —not shown). Hoist cart  32  is mounted to I-Beam  23  by placing wheels  33   c  and  33   d  (not shown) that are secured to top ends of hoist frame  34  over I-Beam  23 . The other end of hoist cart  32  is secured to trolley assembly  24  via anchor pin  37   a . As trolley assembly  24  and trolley motor  31  moves along I-Beam  23 , hoist cart moves with it. Hoist  25  is mounted on its side and secured to hoist frame  34  via hoist anchor bracket  35  with anchor pin  37   b . Hoist frame flange holds hoist  25  in a static and horizontal position so that when tension on chain  26  is reduced or eliminated that hoist will stay in a fixed position.  
      Although the term “wheels” is used frequently in this specification, it merely describes the preferred embodiment. The term “wheels”  33  can be any low-friction device or rotating means including, but not limited to, wheels, slides, and skids. And although the term “chain” is used frequently in this specification, it also merely describes the preferred embodiment. The “chain”  26  can be any tension-bearing element including, but not limited to, chain, cable, rope, strap, and wire rope.  
      If hoist  25  were allowed to rotate on anchor pin  37   b  and rotate downward, damage to hoist  25 , chain  26  and hoist cart  32  may occur. To guide chain  26  from hoist  25  on a horizontal direction to a position under trolley assembly  24  and over bulk bag  29 , chain wheel  40  is mounted to hoist cart  32  at or near anchor pin  37   a . Typically, hoist  25  comes from the manufacturer, pre-wired with a safety switch to stop chain  26  movement as chain hook  39  moves against bottom of hoist  25 . Limit switch  38  is mounted to hoist cart  32  under chain wheel  40  so the lifting operation of hoist  25  will stop as chain hook  39  presses against it. Hoist  25  is mounted away from the area under trolley assembly  24  so that bulk bag  29 , bag frame  28  can be lifted as close to I-Beam  23  as possible. Chain bag  30  may be secured to hoist  25  collect chain  26   b  as hoist  25  is used in the lift mode. Bulk bag  29  may now be made larger to hold a greater capacity and still fit between support tray  85 , mounted on cross beam supports  86 , and I-Beam  23 .  
       FIG. 2  is a side view of bulk bag unloader  20  with bag  29  positioned on a floor ready to be lifted for placement on support tray  85  for unloading. Hoist  25  is mounted on its side to hoist frame  34  and is located approximately 30″ to the side of chain wheel  40 . Chain wheel  40  and hoist  25  are secured to hoist cart  32  so that as trolley assembly  24  and trolley motor  31  moves along I-Beam  23 , the distance between chain wheel  40  and hoist  25  is fixed.  
       FIG. 3  is a side view of bulk bag unloader  20  with bag  29  lifted to its maximum height (within a few inches) under I-Beam  23  and top frame support  21 .  
       FIG. 4  is a front view of bulk bag unloader  20  with bag  29  moved laterally across I-Beam  23  over bag tray  85 . As bulk bag  29  is moved over bag tray  85 , which is supported on cross member(s) of unloader frame  20 , hoist cart  32  and hoist  25  move to end of I-Beam  23 . Typically, I-Beam  23  extends out from corner post  22   d  of unloader frame  20  a distance from the center opening of bag tray  85  and end of hoist cart  32  to a point at approximately the location of wheel  33   c  on hoist frame  34 .  
       FIG. 5  is a side view of bulk bag unloader  20  with bag  29  lowered onto bag tray  85  so that bag  29  can be discharged. As bag  29  is lifted from floor, excess chain  26  will collect in chain bag  30  that is secured to hoist  25 .  
       FIG. 6  is a side view of bulk bag unloader  20  with I-Beam  23  secured to top frame support  21 . I-Beam  23  may be permanently welded to unloader frame  20  or bolted to top frame support  21  by using I-Beam brackets  27   a ,  27   b ,  27   c  and  27   d . By welding I-Beam brackets  27   a  and  27   c  to top frame support  21  and I-Beam brackets  27   b  and  27   d  to I-Beam  23 , I-Beam  23  may be secured to top frame  21  when I-Beam brackets  27   a  and  27   b  and I-Beam brackets  27   c  and  27   d  are bolted together respectively. Trolley assembly  24 , which typically holds hoist  25  via anchor pin  37   b , is mounted to I-Beam  23  in the same manner as for normal hoist operation. Hoist cart  32  comes complete as a single unit with hoist frame  34 X, hoist frame flange  36 , hoist anchor bracket  35  and wheel(s)  33   c  (and  33   d —not shown). Hoist cart  32  mounts to I-Beam  23  by placing wheels  33   c  and  33   d  (not shown) that are secured to top ends of hoist frame  34  over I-Beam  23 . The other end of hoist cart  32  is secured to trolley assembly  24  via anchor pin  37   a . As trolley carriage  24  and trolley motor  31  moves along I-beam  23 , hoist cart  32  moves with it. Hoist  25  is mounted in its typical vertical or hanging position and secured to hoist frame  32  via hoist anchor bracket  35  with anchor pin  37   b . To guide chain  26  from hoist  25  to chain wheel  40   a , over bag  29 , chain wheel  40   c  is located directly under hoist  25 . To prevent chain  26  from coming in contact with bag  29  and or bag lift frame  28 , chain wheel  40   b  is located on hoist frame  34 X. Typically, hoist  25  comes from the manufactured pre-wired with a safety switch to stop chain  26  movement as chain hook  39  moves against bottom of hoist  25 . Limit switch  38  is mounted to hoist cart  32  under chain wheel  40  so the lifting operation of hoist  25  will stop as chain hook  39  presses against it. Hoist  25  is mounted away from the area under trolley assembly  24  so that bulk bag  29 , bag frame  28  can be lifted as close to I-Beam  23  as possible. Chain bag  30  may be secured to hoist  25  to collect chain  26  as hoist  25  is used in the lift mode. Bulk bag  29  may now be made larger to hold a greater capacity and still fit between support tray  85 , mounted on cross beam supports  86 , and I-Beam  23 . To prevent slack in chain  26  from occurring and allowing chain to come off of chain wheels  40   a ,  40   b  and  40   c , proximity switch  42  mounted on bracket  41  to shut hoist  25  off. It is important to maintain some tension on chain  26  so that it does not become loose and disengage from chain wheels  40   a ,  40   b  and  40   c.    
       FIG. 7  is a detailed side view of cart  32  and hoist frame  34 X shown as a single unit. Hoist  25  is mounted in a vertical position in this view and secured to cart  32  by placing pin  35  through hoist bracket  36  and anchor bracket  35 . Hoist  25  is mounted to hoist cart  32  and is located approximately 30″ to the side of chain wheel  40   a . Chain wheels  40   a ,  40   b  and  40   c  and hoist  25  are secured to hoist frame  34 X and hoist cart  32  so that as trolley assembly  24  and trolley motor  31  moves along I-Beam  23 , the distance between chain wheel  40   a  and hoist  25  is fixed. Switch  42 , mounted on flange  41  of hoist frame  34 X, ensures that tension in chain  26  is maintained when the bag frame  28  is lowered. If any slack in the chain  26  occurs, switch  42  will detect the slack and shut hoist  25  off.  
      To prevent bag lift frame from becoming jammed against trolley carriage  24  and causing possible damage to chain wheel  40   a  and cart frame  32 , limit switch  38  monitors movement of bag lift frame  28  and coupler  39  and shuts hoist  25  off when switch  38  is tripped. Trolley cart  32  is moved back and force across I-Beam  23  (not shown) to trolley motor and drive  31 . Trolley cart  32  is held onto and allowed to travel along I-Beam  23  (not shown) by trolley wheels  33   c ,  33   a  and trolley wheels  33   b  and  33   d  (not shown). Trolley wheels  33   a ,  33   b ,  33   c  and  33   d  are held onto hoist cart  32  by flange supports  32   a  and  33   b ,  32   c  and  32   d  (not shown.)  
       FIG. 8  is a front view of bulk bag unloader  20  with bag  29  raised to its maximum height (within a few inches) under I-Beams  23   a  and  23   b  and top frame support  21  by using a hoist carriage  24   tw  made up of twin I-Beams  23   a  and  23   b  and inverted bag lift frame  281   p . Hoist carriage assembly  24   tw  is positioned between I-Beams  23   a  and  23   b  so that hoist  25  may be located only a few inches under top frame  21  of unloader  20 . Hoist carriage assembly  24   tw  is equipped with wheel assemblies  32   xa  and  32   xb  and trolley motor and drive  31  to move bag  29  back and forth along I-Beams  23   a  and  23   b . Inverted bag lift frame  281   p  allows bag  29  to be raised higher than standard lift frames by enabling slack in the side walls of bag  29  near its top area, typically long the vertical sides of bag  29  where lifting loops  28 X and  28   y  are attached, so that material in bag maybe positioned directly under (and in contact if necessary) so that bag  29  will clear bag platform  85 . Bag lifting loops  28 X and  28   y  of bag  29  may be placed inside of bag frame end flanges  43   a  and  43   b  ( 43   c  and  43   d  not shown) so that end of lifting loops  28 X and  28   y  can be secured to posts  45   aa  and  45   ab.    
       FIG. 9  is a detailed front view of one embodiment of hoist carriage assembly  24   tw . Front support posts  22   c  and  22   d  of unloader  20  are connected on top by top support  21 . I-Beams  23   a  and  23   b  may be secured to top support  21  by welding or other fastening means. Hoist  25  is secured hoist frame  24   tw  by placing hoist pin  37   b  through flange bracket  36  that is secured to hoist frame  24   tw  and through hoist bracket  35  that is attached to hoist  25 . Wheel support flanges  24   fa  and  24   fb  and wheels  24   wa  and  24   wb  are secured to the outer vertical wall of hoist frame carriage  24   tw  to provide linear stability when trolley motor and drive  31  starts and stops. With trolley motor and drive  31  connected to fixture  32   xa  of I-Beam  23   a  only, far end of hoist carriage assembly  24   tw  may jerk towards the inside walls of either I-Beam  23   a  and  23   b  and possibly jam or slow its movement when stopping and starting in both directions. Hoist carriage frame  24   tw  may use cross supports and or gussets (not shown) between in inside vertical walls to provide more stability when hoist  25  is under load. The primary advantage of hoist carriage frame  24   tw  utilizing two parallel I-Beams  23  and  23   b  over hoist frame  24  (not shown) is that hoist  25  may be operated without extra chain wheels  40   a ,  40   b  and  40   c  (not shown) and switches  38  (also not shown.)  
       FIG. 10  is a side view of the top section of hoist frame  20   f , which may be used to lift bulk bags as well as other loads, with I-Beam  23   b  secured to top support  21  on front vertical supports  22   c  and  22   d . Hoist frame carriage  24   tw  is secured to I-Beam  23   b  by wheel  33   fd  and wheels  33   fa ,  33   fb ,  33   fc ,  33   ba ,  33   bb ,  33   bc  and  33   bd  (not shown) Trolley motor and drive  31  is secured to hoist frame carriage  24   tw  and provides the lateral movement of hoist carriage frame  24   tw  along I-Beam  23   b  and  23   a  (not shown.) I-Beam  23   b  may be extended beyond vertical support  22   c  (or support  22   d .) Chain  26  extends down from hoist  25 . Guide wheel  24   wb  is shown located at the opposite end of trolley motor and drive  31  on hoist carriage frame  24   tw.    
       FIG. 11  is a detailed front view of inverted bag lift frame  28 LP secured to chain  26  of hoist  25 . Chain hook/support bracket  39  is secured between lift arms  28   a  and  28   b  of inverted bag frame  28 LP. In this configuration, hoist  25  is secured to a standard trolley carriage  32  that is attached to a single I-Beam  23 . Inverted bag lift frame  28 LP is shown with arms  28   a  and  28   b  extending upward from the center of unit where chain  26  is coupled. At the end of arms  28   a  and  28   b , end flanges  43   a  and  43   b  are located respectively, to allow adjustment of bag lifting straps (not shown) by placing lock pin  46  (not shown) in one of the holes  44   aa ,  44   ab  and  44   ac  of end flange  43   a , and one of the holes  44   ba ,  44   bb  and  44   bc  of end flange  43   b . Together with posts  45   aa  and  45   ab  of arm  28   a  and posts  45   ba  and  45   bb  of arm  28   b , approximately six different points of lifting strap attachment are possible.  
      Notice that posts  45   aa ,  45   ab ,  45   ba  and  45   bb  have a perpendicular and horizontal flange on top to keep a bag strap from slipping off.  
       FIG. 12  is a top view of bag frame  28  showing arms  28   a ,  28   b ,  28   c  and  28   d . Bracing supports  47   a  and  47   b  are placing in the center of bag frame  28  where chain  26  (not shown) will be connected. Posts  45   aa  and  45   ab ,  45   ba  and  45   bb , and  45   ca  and  45   cb , and  45   da  and  45   db  are located on arms  28   a ,  28   b ,  28   c  and  28   d  respectively. Notice that top flanges of posts  45   aa ,  45   ab ,  45   ba ,  45   bb ,  45   ca ,  45   cb ,  45   da  and  45   db  can be angled slightly off center if desired. Lock pins  46   a ,  46   b ,  46   c  and  46   d  may be located holes  44   aa ,  44   ab ,  44   ac ,  44   ba ,  44   bb ,  44   bc ,  44   ca ,  44   cb ,  44   cc ,  44   da ,  44   db  or  44   dc  of end flanges  43   a ,  43   b ,  43   c  and  43   d  respectively to provide for adjustment of bag lifting loops  28   v ,  28   w ,  28 X and  28   y  (not shown). Lock pins may also be used to hold snap rings  48   a ,  48   b ,  48   c  and  48   d  (also not shown.)  
       FIG. 13  is a detailed front view of one arm of inverted bag frame  28 LP equipped with snap ring  48 . Snap ring  48  is secured to inverted bag frame  28 LP by placing lock pin  46  through hole  43   ba  of end flange  43   b . Because inverted bag frame  28 LP may have a difference in height of more than 8″ between its center chain coupling area and the end flanges, a snap ring may be required to hold the straps of completely full bags of material (incapable of being raised upward using slack on the sidewall of the bag) since the average length of bag lifting loops straps is 10″.  
       FIG. 14  is a detailed front view of bag lift frame  28  that is secured to chain  26  of hoist  25  on trolley carriage  32 . In this configuration, bag lift frame  28  is horizontal and not inverted but retains the same adjustment components such as posts  45   aa ,  45   ab ,  45   ac  and  45   ad  in conjunction with holes  44   aa ,  44   ab , and  44   ac  of end flange  43   a  and holes  44   ba ,  44   bb  and  44   bc  of end flange  43   b.    
      While there have been described what are at present considered to be the preferred embodiments of this invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the invention, and it is, therefore, aimed to cover all such changes and modifications as fall within the true spirit and scope of the invention.