Abstract:
An improved bulk bag with an upper portion of the sidewalls that is sloped inward from vertical so that when the fabric is stretched upward in the lifting process, thereby creating tension in the vertical fabric, the tension will be maintained after the bag is no longer in a lift position, as the fabric cannot slide back down around the product due to the restricted size of the fabric and such tension provides stronger restrictions to product movement to provide increased stability.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority from provisional patent application, entitled “Improved Design for Stabilizing Fabric Bulk Bags,” filed on Nov. 9, 2005, bearing Ser. No. 60/735,642, incorporated herein by reference thereto. 
     
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    Not applicable 
       REFERENCE TO A “MICROFICHE APPENDIX” 
       [0003]    Not applicable 
       BACKGROUND OF THE INVENTION 
       [0004]    1. Field of the Invention 
         [0005]    The apparatus of the present invention relates to fabric bulk bags and more particularly to an improved bulk bag having at least the upper portion of the side walls extending inward from the vertical to allow the material in the bag to stabilize the filled bag. 
         [0006]    2. General Background and Description of the Invention 
         [0007]    Over the history of the use of bulk bags, one of the greatest issues has been the stabilization of bulk bags being carried on pallets and stacked in warehouses. Historically, bulk bags, when “filled” with product, are never actually full, and would show loose fabric on the top, due to settling of the product. The problem of stabilization was never an issue for bags being carried by the loops because in the suspended condition, there is tension on the side walls to keep the product in a stable position. 
         [0008]    However, once the bag is placed on a platform, such as the floor or a wood pallet, there no longer is the side wall tension, and the bag is able to slump and bulge in response to any product movement. This is why one of the most common instructions for filling these fabric bags is start with the bag&#39;s bottom corners 2 to 3 inches above the platform. This position automatically applies tension to the side walls and encourages the product into good vertical columns. Once the bag is released, there is no longer anything holding the vertical tension in the side walls and product shaping within the bag is left to the fabric. As long as the fabric stays tightly stretched around the product, the bag&#39;s appearance and performance when being handled is good. 
         [0009]    However, in all the current designs that this inventor is aware of, the side walls of the bag are dimensionally equal from top to bottom. Therefore, any space at the top of the bag, allows the fabric to slip down the sides of the product columns. This produces extra fabric, which is no longer filled, to be adjacent to the product. This provides product with inertia from movement or transportation to have chance to move and destabilize the bag. 
         [0010]    Therefore, there is a need in the industry to provide a bulk bag which when filled, and moved, or lifted, the product in the bag is undisturbed, and when returned to its position, maintains the sidewalls firm, with no sagging or slipping, to allow stability to the bag, and allow other bags to be stacked thereupon. 
       BRIEF SUMMARY OF THE INVENTION 
       [0011]    The improved bag of the present invention addresses this problem in a very simple and straight forward manner. What is provided is an improved bulk bag which includes the design of shrinking the outer dimensions of the bag so that the top of the bag is significantly smaller than the bottom of the bag, by forming one or more darts, as defined herein, either on one or more corners of the bag or along one or more sidewalls. By forming at least a portion of the bag sidewalls to face inwardly from the vertical, there is created a situation whereby the fabric remains in tension at all times. That is, the fabric cannot slip down around the product as the product downwardly adjacent to any portion of fabric is bigger in diameter than the fabric. The product would have to ‘squeeze’ upward to fit into the smaller fabric space. 
         [0012]    Therefore, it is a principal object of the present invention to provide a new bag design whereby the bag cannot slip down and create space for movement; 
         [0013]    It is a further object of the present invention to provide a bag design whose stability producing tension can be achieved even if the bag is only partially full; 
         [0014]    It is a further object of the present invention to provide a bag that will remain stable although a range of product heights is used in a single bag; 
         [0015]    It is a further object of the present invention to provide a bag that will remain stable even though product within the bag shifts due to density changes or when a user uses a single bag for multiple products; 
         [0016]    It is a further object of the invention to provide a bag whereby although product can shrink and reduce in height, the bag will still provide support as long as the product is maintained inside the bags design that is enlarging as the product shrinks; 
         [0017]    It is a further object of the present invention to provide an improved bulk bag that prevents the slumping of sidewalls and product by providing an upper portion of the sidewalls that slopes inward from vertical, with the use of one or more darts, so that the product maintains the fabric in its full vertical position; 
         [0018]    It is a further object of the present invention to provide an improved bulk bag with an upper portion of the sidewalls that is sloped inward from vertical so that when the fabric is stretched upward in the lifting process, thereby creating tension in the vertical fabrics, the tension will be maintained after the bag is no longer in a lift position, as the fabric cannot slide back down around the product due to the restricted size of the fabric and such tension provides stronger restrictions to product movement to provide increased stability. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0019]    For a further understanding of the nature, objects, and advantages of the present invention, reference should be had to the following detailed description, read in conjunction with the following drawings, wherein like reference numerals denote like elements and wherein: 
           [0020]      FIG. 1  illustrates a side view of a conventional prior art bulk bag filled with product; 
           [0021]      FIG. 2  illustrates the filled bulk bag in  FIG. 1  being lifted by a forklift; 
           [0022]      FIG. 3  illustrates the filled bulk bag in  FIG. 2  being returned to its position after being lifted, whereby the vertical sidewalls sag, after time and/or movement, around the product in the bag; 
           [0023]      FIG. 4  illustrates an overall view of the new and improved bag of the present invention; 
           [0024]      FIG. 4A  illustrates an overall view of the improved bag with the darts formed along the sidewalls; 
           [0025]      FIG. 5  illustrates a side view of the improved bag of the present invention; 
           [0026]      FIG. 6  illustrates an isolated view of the upper end of the improved bag of the present invention; 
           [0027]      FIG. 7  illustrates a top view of the improved bag of the present invention; 
           [0028]      FIGS. 8 through 11  illustrate variations in the upper end configuration of the bag of the present invention; 
           [0029]      FIG. 12  illustrates a representational view of the forces acting on the side walls of the bag of the present invention when filled with bulk; 
           [0030]      FIG. 13  illustrates an isolated view of forces acting on the upper portion of the bag of the present invention when containing bulk; 
           [0031]      FIG. 14  illustrates an alternate embodiment of the improved bag of the present invention; and 
           [0032]      FIG. 15  illustrates two bags of the present invention stacked upon one other filled with bulk. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0033]      FIGS. 1 through 3  illustrate a prior art bag, while  FIGS. 4 through 15  illustrate the improved bag of the present invention. 
         [0034]    Prior to a discussion of the present invention, reference is made to  FIGS. 1 through 3 , which illustrate a prior art bag  10  and the problems confronted which such a bag  10  when filled with bulk material. As seen in  FIG. 1 , prior art bag  10  is a conventional bag having vertical sidewalls  12 , a top  14 , and resting on a base  16 . The bag  10  includes four lifting loops  18 . In this illustration, the bag  10  is filled with a dry bulk material, which cannot be seen. In  FIG. 2 , the bag  10  has been lifted by lifting loops  18 , by a forklift, for example, so that the base  16  is no longer resting on a surface. The bulk material in the bag  10  would tend to settle within the bag space, in the direction of arrow  15 . In  FIG. 3 , when the bag  10  is returned to rest on its base  18 , the vertical sidewalls  12 , which have been pulled upward, when lifted, return to their position, because the bulk has settled in the bag, the sidewalls  12  slide downward, and tend to form creases and folds  20 , which are very undesirable, especially if other filled bags  10  are placed atop the bag  10  illustrated. 
         [0035]    Almost every product moves after being poured into the bag. It densifies (settles) with time or during handling and shipping. The particles are irregularly shaped and the movement allows these particles to lodge closer and closer together, thus reducing the product height. By lifting the bag by the loops after filling, a great percentage of this settling is achieved immediately. At the same time, during the lift, the fabric is stretched and the widest part of the fabric is raised above the maximum amount of product and the maximum amount of the restricted portion of the bag is raised above the product to hold as much tension as possible. 
         [0036]    With all of this in mind, there created a need for a bag to be designed to match the product characteristics in a manner that the intended amount of product initially fits into the bag and the settled or densified product is still above a certain point along the sidewalls of the bag, after the required lifting and stretching of the fabric to improve stability. The present invention addresses this need. 
         [0037]    The bag of the present invention, as illustrated by the numeral  100  in  FIGS. 4 through 15 , solves this problem in the art. As seen first in  FIG. 4 , bag  100 , is filled with a bulk material, usually a powder or granular material. As seen bag  100  includes a plurality of side walls  102 , extending upward from a base  104 , and terminating in a top portion  106 . As with most bags, the top  106  includes an opening  108 , into which the bulk material is poured into the bag  100 , and is closed via an iris fabric closure  110 . 
         [0038]    Unlike any previous bulk bag known to the inventor, bag  100  includes an improvement which eliminates sagging of the side walls  102 , at any time while filled with bulk material. This improvement is illustrated clearly in isolated view in  FIG. 6 . At each corner  109  of the bag  100 , there is formed a dart  112 , the dart  112  extending from a point  114  below the upper end of the sidewalls  102 , and formed inward along the top  106 , which results in each of the upper portion  115  of the four sidewalls  102 , from point  114 , angulated inward along sew line  107 , so as to define a truncated pyramid  118 , from point  114  to the top portion  106  of the bag. This can be clearly seen in side view in  FIG. 5  and in overall view in  FIG. 4 . 
         [0039]    As an alternative, as illustrated in  FIG. 4A , the darts  112  may be formed along at least one, or up to all four sidewalls  102  of the bag  100 , terminating at their upper end at top  106 , and the same effect would be achieved as having the darts  112  formed on the corners as seen in  FIG. 4 . 
         [0040]    For purposes of definition, a “dart” is defined herein as a line of stitching extending from a point along the sidewall upwards to the top of the bag at an angle so that two or more layers of fabric form the dart, but preferably two layers. The dart may be formed at one or more corners of the bag sidewalls or anywhere along one or more sidewalls between the corners. An example of a dart formed on the corner as defined herein is shown in  FIG. 6A , while an example of a dart formed along the sidewall is shown in  FIG. 4A . 
         [0041]      FIGS. 7 through 11  illustrate the formation of the truncated pyramid  118  having varying heights.  FIG. 7  illustrates a top view of the filled bulk bag  100 , with the four upper portion sidewalls  115 , extending at an angle from the vertical to the top  106 . As seen in  FIG. 7 , the shape of the bag  100  takes on an almost circular shape, when filled with bulk material. 
         [0042]    In  FIGS. 8 through 10 , there is illustrated the bag  100  filled with bulk material  101 , to a point  103 . In each of the representational drawings, the bulk material  101  is filled to a point above the point  114 , i.e. the point at which the dart  112  is formed along each sidewall  102 . This fact will be critical and more fully explained. However, for purposes of  FIGS. 8 through 10 , arrows  130 , show the vertical line  131 , while arrows  132  illustrate the angulated upper sidewalls  115 , when the dart  112  is formed in varying lengths, which define a greater upper truncated pyramid portion  118  on the bag. In  FIG. 11 , the dart  112  is formed extending from the base  104 , extending upward to the top  106 , so that in effect each side wall  102  becomes a truncated pyramid  118 , while no portion of the sidewall  102  is vertical, unlike the previous embodiments. 
         [0043]    As was explained earlier in reference to the prior art bag shown in  FIGS. 1 through 3 , the improvement as described above, in relation to  FIGS. 4 through 11 , solves the sagging side wall problem confronted in the art. It has been found through experimentation, that when the side walls  102  are designed to include an upper truncated pyramid portion  118 , formed by the darts  112  at each corner, when bulk material is poured into the bag above the lowest point of the angulated wall portions  115 , the bulk will stay firm against the bag sidewalls  102 , and eliminate sagging or folding of the walls as experienced by all other filled bulk bags. 
         [0044]    The experiments show, as illustrated in  FIGS. 12 and 13 , that the bulk material  101  which is poured above the lowest point of the angulated walls  115 , as seen in  FIG. 13 , for example, the upper portion sidewalls  115  define an area smaller than the lower vertical sidewalls  102 . Therefore when the bag  100  is raised and returned to its rest, the angulated sidewalls  115 , having a smaller diameter than the lower, vertical sidewalls  102 , cannot slide past the upper sidewall space, and therefore are maintained tight, and without any sags or folds. As seen in  FIGS. 12 and 13 , arrows  146  illustrate the forces within the bag acting outward on the vertical sidewalls  102  and the angulated sidewalls  115 . These forces continue to act on the sidewalls when the bag is stationary or being transported, and when the bag is returned to its resting place, the upper sidewalls  115  are unable to travel into the larger space defined by the vertical sidewalls  102 , and therefore the bag is maintained erect and with the capacity to have other filled bags stacked upon it. In all cases when this principle is at work is when the bulk material within the bag has been filled to a point above the lowest point of the formation of the angulated sidewalls, which would be point  114 , as illustrated in  FIG. 13 . 
         [0045]      FIG. 14  illustrates an embodiment of bag  100 , which may be a bag formed by material which when woven, would define a bag having vertical sidewalls  102  to a certain point, and then the weave would define the smaller upper truncated portion  118  of the bag. That is, rather than darts  112  being sewn in the bag to achieve the smaller truncated upper portion  118 , the weave of the fabric would define this feature. 
         [0046]    As seen in  FIG. 15 , there is illustrated a first lower bag  100  filled with bulk, with a second bulk bag  100 , also filled with bulk, resting atop lower bag  100 . As seen in this figure, the particular bulk bag being utilized with the present invention is a “pot-bellied” bulk bag, of the type having a pair of channels  150 , each housing a rigid insert  152 , therein, the channels spaced apart to receive the tynes of a forklift. The channels are secured to a pot-bellied portion  154 , filled with bulk, between the channels to define a firm and rigid base  156  of each of the bags, which allows ease in stacking. This base feature combined with the present invention insures bags which can be stacked safely and securely, without risking loss of firmness in the sidewalls of the bags. 
         [0047]    Likewise, this new design can probably be used to modify any existing design such as circular woven, u-panel, one piece bags, baffle bags, Portabulk, etc. 
         [0048]    All measurements disclosed herein are at standard temperature and pressure, at sea level on Earth, unless indicated otherwise. 
       PARTS LIST 
       [0049]      
         [0000]    
       
         
               
               
             
               
               
             
           
               
                   
               
               
                 Part Number 
                 Description 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 10 
                 prior art bag 
               
               
                 12 
                 side walls 
               
               
                 14 
                 top 
               
               
                 15 
                 arrow 
               
               
                 16 
                 base 
               
               
                 18 
                 lifting loops 
               
               
                 20 
                 folds 
               
               
                 100 
                 bag 
               
               
                 101 
                 bulk material 
               
               
                 102 
                 side walls 
               
               
                 103 
                 point 
               
               
                 104 
                 base 
               
               
                 106 
                 top portion 
               
               
                 107 
                 sew line 
               
               
                 108 
                 opening 
               
               
                 109 
                 corner 
               
               
                 110 
                 fabric closure 
               
               
                 112 
                 dart 
               
               
                 114 
                 point 
               
               
                 115 
                 side walls 
               
               
                 118 
                 truncated pyramid 
               
               
                 130 
                 arrows 
               
               
                 131 
                 vertical line 
               
               
                 132 
                 arrows 
               
               
                 146 
                 arrows 
               
               
                 150 
                 channels 
               
               
                 152 
                 rigid insert 
               
               
                 154 
                 pot belly portion 
               
               
                 156 
                 rigid base 
               
               
                   
               
             
          
         
       
     
         [0050]    The foregoing embodiments are presented by way of example only; the scope of the present invention is to be limited only by the following claims.