Abstract:
Bulk bag loop retainers used in conjunction with bulk bag lifting frames. Each retainer includes opposed retainer plates secured to the lifting frame. The plates are shaped and dimensioned and aligned relative to one another to define a non-linear passage into a retainment area which receives and retains the bag loop.

Description:
BACKGROUND OF THE INVENTION 
     The present invention generally relates to bulk bag lifting frames. More particularly, the invention relates to retainers used in conjunction with bag lifting frames which permit easier loading and unloading of bags from the lifting frame. 
     Large bag like containers are often used for the shipment of bulk materials from one location to another. These bulk bags have a capacity ranging from approximately twenty cubic feet up to seventy cubic feet. The bulk bags are generally constructed with bag loops on the top of the bag which are connected to a lifting frame for holding the bags while they are being filled or emptied and occasionally for transporting the bags from one location to another. The bag loops are generally constructed of a strong web-like material which is sewn onto the upper corners of the bag. 
     The bag lifting frames generally comprise a system of horizontal frame members adapted to be supported by a hoist (See FIG. 2) or a fork lift (See FIG.  7 ), or other support means. Most prior art bag lifting frames include hooks or clips for holding the bag loops. A representative prior art hook  20  is shown in FIG.  1 . The hook  20  is mounted on the horizontal frame member  12  and includes a J-bend portion  22  which receives and supports the loop  42  and a clasp member  24  which closes the hook  20  to prevent inadvertent release of the bag loop  42 . The clasp member  24  is generally biased to the closed position. During loading of a bag, the biased clasp member  24  gives to permit the loop  42  to be looped over the J-bend  22 . While it may be possible to load a loop with one hand, the process often requires a second hand to prevent rotation of the clasp member  24  during loading. Additionally, the loop  42  must be aligned close to the center of the J-bend  22 , otherwise the frame may be subject to undesirable side loads. To remove the loop  42 , the clasp member  24  must be forced toward and maintained in an open position to permit the loop  42  to be removed. Such a process generally requires two hand operation, one hand to open the clasp member  24  and a second to lift the loop  42  out of the hook  20 . While it may be possible to release a loop with one hand, such a process requires great dexterity and subjects the operator to possible pinching by the clasp or other dangers. 
     As such, there is a need for a loop retainer which allows easier loading and unloading of a bag loop. 
     SUMMARY 
     The present invention relates to bag loop retainers used in conjunction with bulk bag lifting frames. The retainers include opposed first and second retainer plates which are secured to the lifting frame. The plates are aligned relative to one anther such that a projecting portion of one of the plates nests within an receiving portion of the other plate. The plates thereby define a non-linear passage into a retainment area which receives and retains the bag loop. In the preferred embodiment, the plates are configured such that the passage has a zig-zag configuration. passage has a zig-zag configuration. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side elevation of a prior art loop hook. 
     FIG. 2 is an isometric view of a bag lifting frame incorporating the loop retainers of the present invention. 
     FIG. 3 is a view along the line  3 — 3  in FIG.  2 . 
     FIGS. 4-6 are section views similar to FIG. 3 illustrating the progression of a bag loop being loaded into one of the loop retainers of the present invention. 
     FIG. 7 is an isometric view of an alternate lifting frame incorporating loop retainers of the present invention. 
     FIG. 8 is a view taken along the line  8 — 8  in FIG.  7 . 
     FIG. 9 is a side elevation of an alternative loop retainer of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The preferred embodiments will be described with reference to the drawing figures wherein like numerals represent like elements throughout. 
     Referring to FIG. 2, a hoist type lifting frame  10  is shown holding a bulk bag  40  by bag loops  42 . The lifting frame  10  includes a plurality of horizontal frame members  12 , an eye bolt  14  for attachment to a hoist cable (not shown), and a plurality of loop retainers  50 . The horizontal frame members  12  are configured such that the loop retainers  50  are positioned proximate to the positions of the bag loops  42 . 
     Referring to FIG. 3, each loop retainer  50  includes a pair of opposed retainer plates  52  and  54  which define chute opening  60 , passageway  62 , and retainment area  64 . As will be described in more detail hereinafter, the chute opening  60  has sloped edges which direct the loop strap  42  toward the passageway  62  which preferably has a zig-zag configuration to reduce the likelihood of inadvertent release from the retainment area  64 . The retainer plates  52  and  54  are positioned relative to one another such that the passageway  62  is an approximately one-quarter inch gap between the plates  52  and  54 . The gap can be increased or decreased depending on the desired application. 
     Retainer plate  52  includes an attachment portion  52   a  and two bend portions  52   b ,  52   c . The attachment portion  52   a  is preferably welded to the end of the horizontal frame member  12 . Other attachment means, for example, bolts or screws, may also be used. Additionally, although it is preferable to position retainer plate  52  at the end of horizontal frame member  12 , other positioning is contemplated depending on the demands of a particular application. The first bend portion  52   b  of retainer plate  52  extends up from the attachment portion  52   a  at an inward angle toward retainer plate  54  such that it is at an acute angle relative to the upper surface  12   a  of the horizontal frame member  12 . The second bend portion  52   c  of retainer plate  52  extends outward, away from retainer plate  54 , at a substantially right angle relative to the first bend portion  52   b.    
     Retainer plate  54  includes an attachment portion  54   a  and four bend portions  54   b ,  54   c ,  54   d ,  54   e . The attachment portion  54   a  is preferably welded to the upper surface  12   a  of the horizontal frame member  12 . Again, other attachment means may also be used. The first bend portion  54   b  of retainer plate  54  extends up from the attachment portion  54   a  at an inward angle, toward retainer plate  52 , such that it is also at an acute angle relative to the upper surface  12   a  of the horizontal frame member  12 . The second bend portion  54   c  of retainer plate  54  extends outward, away from retainer plate  52 , at a substantially right angle relative to the first bend portion  54   b . The third bend portion  54   d  of retainer plate  54  extends inward, toward retainer plate  52 , at a substantially right angle relative to the second bend portion  54   c . The fourth bend portion  54   e  of retainer plate  54  extends outward, away from retainer plate  52 , at a substantially right angle relative to the third bend portion  54   d.    
     The retainer plates  52  and  54  are sized and positioned such that the retainment area  64  is defined by a portion of retainer plate  52  first bend portion  52   b  and retainer plate  54  first bend portion  54   b . The passageway  62  is defined by both bend portions  52   b  and  52   c  of retainer plate  52  and second and third bend portions  54   c  and  54   d  of retainer plate  54 . The angling of the various portions and the relative size and positioning defines three inward projections  55   a ,  55   b ,  55   c  and an indentation  56  which create the zig-zag of passageway  62 . Projection  55   b  is nested in the indentation  56 , that is, the projection  55   b , extends into the indentation  56  such that an imaginary vertical plane P extends through portions  54   c  and  54   d  defining the indentation  56  and through portions  52   b  and  52   c  defining projection  55   b . The chute opening  60  is defined by the second bend portion  52   c  of retainer plate  52  and the fourth bend portion  54   e  of retainer plate  54 . The chute opening  60  funnels toward the passageway  62  to direct the loop strap  42  into the passageway  62  and ultimately the retainment area  64 . 
     The retainer plates  52 ,  54  are preferably manufactured from one-quarter inch thick, two inch wide steel flat bar and may be formed with their desired configurations or may be configured after forming. Other materials may also be used. The plates  52 ,  54  are preferably rigid to maintain structural integrity. 
     Referring to FIGS. 4-6, the progression of a bag loop  42  being loaded within a retainer  50  is shown. The loop is placed over the chute opening  60  and pulled down thereon. As explained above, the bend portions  52   c  and  54   e  define chute opening  60  with a funnel like configuration which directs the loop  42  toward passageway  62 . As the loop is pulled through the chute opening  60 , the funnel shape causes the loop  42  to begin folding upon itself as illustrated in FIG.  4 . As the loop travels further into the passageway  62 , it folds further upon itself, as illustrated in FIG. 5, thereby permitting the loop strap  42  to pass through the passageway  62 . As the loop  42  travels into the retainment area  64 , it relaxes as illustrated in FIG.  6  and is positioned within the retainment area  64 . With the zig-zag passageway  62 , slacking of the loop  42  will not permit the loop  42  to release from the retainer  50 . Even if however, the loop  42  were to partially release, weighting of the bag or other tensioning of the loop  42  would simply cause the loop  42  to travel back through the passageway  62  into the retainment area  64 . To remove the loop  42 , the loop  42  is lifted with sufficient force to fold the loop  42  upon itself as it travels out of the retainer  50  in a manner similar to its entry. This generally can be accomplished with one hand. In the preferred configuration shown, the opening into the passageway  62  and the passageway  62  itself are identical whether travel is into the retainment area  64  or out of the retainer  50 , that is, opposed surfaces in a funnel-like configuration leading to a zig-zagging passageway. 
     Referring to FIGS. 7 and 8, the preferred retainers  50  are shown in use with an alternate lifting frame  100 . The lifting frame  100  includes a plurality of horizontal frame members  12  and may include an eye bolt  14 . The frame  100  further includes two channels  16  for receiving fork lift tines (not shown). The retainers  50  are substantially as described above, but are each attached to a channel  16  and a member  18  extending therefrom. Otherwise, the retainers  50  operate as described above. 
     Referring to FIG. 9, an alternative embodiment of the retainer  150  is shown. The retainer  150  includes a pair of opposed retainer plates  152  and  154  which define passageway  162  and retainment area  164 . The retainer plates  152  and  154  are positioned relative to one another such that the passageway  162  is an approximately one-quarter inch gap between the plates  152  and  154 . Again, the gap can be increased or decreased depending on the desired application. 
     Retainer plate  152  includes an attachment portion  152   a  and a bend portion  152   b . The attachment portion  152   a  is preferably welded to the end of the horizontal frame member  12 . Other attachment means may also be used. The bend portion  152   b  of retainer plate  152  extends perpendicularly from the attachment portion  152   a  inward toward retainer plate  154  Retainer plate  154  includes an attachment portion  154   a  and two bend portions  154   b ,  154   c . The attachment portion  154   a  is preferably welded to the upper surface  12   a  of the horizontal frame member  12 . Again, other attachment means may also be used. The first bend portion  154   b  of retainer plate  154  extends up from the attachment portion  154   a  perpendicular thereto and the upper surface  12   a  of the horizontal frame member  12 . The second bend portion  154   c  of retainer plate  154  extends perpendicular to the first bend portion  154   b  toward retainer plate  152 . 
     The retainer plates  152  and  154  are sized and positioned such that the retainment area  164  is defined by a portion of retainer plate  152  attachment portion  152   a  and retainer plate  154  first and second bend portions  154   b  and  154   c . The passageway  62  is defined by the attachment.and bend portions  152   a  and  152   b  of retainer plate  152  and the second bend portion  154   c  of retainer plate  154 . The relative size and positioning of the retainer plates  152  and  154  is such that bend portions  152   b  and  154   c  overlap to define the passageway  162 , with bend portion  154   c  sufficiently proximate attachment portion  152   a  to maintain the loop in the retainment area  164 . The  42  loop can be loaded and unloaded by moving it through the passageway  162 .