Abstract:
A side gusseted poly bag with a filling valve and its method of manufacture including a tubular body with opposed side gussets defining front and rear panels, and a filling valve formed by folding the front and rear panels with the interconnecting gusset portion at one corner of the bag inwardly into the bag forming a filling panel, and simultaneously heat sealing the top edges of the front and rear panels with the top edges of the filling panel forming a filling tube and valve that closes itself under the force of material as it rises in the bag.

Description:
BACKGROUND OF THE INVENTION 
     Side gusseted paper bags have been commercially made for many years with openings that permit bag charging or filling. But these bags are quite costly, not only because of the additional materials needed about the bag filling opening, but also because of the labor and time to close and seal the bag. 
     The following patents were found in a preliminary patentability search: 
     
       
         
               
               
               
               
             
           
               
                   
                   
               
               
                   
                 Inventor 
                 U.S. Pat. No. 
                 Issue Date 
               
               
                   
                   
               
             
             
               
                   
                 Harvey 
                 3,276,670 
                 Jul. 27, 1964 
               
               
                   
                 Piazze 
                 3,618,478 
                 Nov. 9, 1971 
               
               
                   
                 Benoit 
                 4,571,235 
                 Feb. 18, 1986 
               
               
                   
                 Benoit 
                 4,655,737 
                 Apr. 7, 1987 
               
               
                   
                 Roen, et al. 
                 4,717,262 
                 Jan. 5, 1988 
               
               
                   
                 Humphrey 
                 4,764,030 
                 Aug. 16, 1988 
               
               
                   
                 Benoit 
                 4,816,104 
                 Mar. 28, 1989 
               
               
                   
                 Olesen 
                 4,881,825 
                 Nov. 21, 1989 
               
               
                   
                 Beer 
                 4,913,561 
                 Apr. 3, 1990 
               
               
                   
                 Gelbard 
                 4,943,167 
                 Jul. 24, 1990 
               
               
                   
                 Mundus 
                 4,959,114 
                 Sep. 25, 1990 
               
               
                   
                 Wood 
                 5,165,799 
                 Nov. 24, 1992 
               
               
                   
                 Gebhardt 
                 5,676,467 
                 Oct. 14, 1997 
               
               
                   
                 Schoeler 
                 5,862,652 
                 Jan. 26, 1999 
               
               
                   
                 Daniels, et al. 
                 Re.36,876 
                 Sep. 19, 2000 
               
               
                   
                 Beer 
                 6,213,645 
                 Apr. 10, 2001 
               
               
                   
                 Angless 
                 6,254,520 
                 Jul. 3, 2001 
               
               
                   
                   
               
             
          
         
       
     
     The Harvey, U.S. Pat. No. 3,276,670, shows a tapered side gusseted bag but has no filling valve. The Piazze, U.S. Pat. No. 3,618,478, shows a gusseted bottom bag with diagonal heat seals but has no filling valve either. 
     The Benoit, U.S. Pat. Nos. 4,571,235 and 4,816,104, show a T-shirt bag with diagonal heat seals at the bottom. Again, it has no filling valve. The Benoit, U.S. Pat. No. 4,655,737, is duplicative with respect to the Benoit &#39;235 patent. 
     The Roen, et al., U.S. Pat. No. 4,717,262, shows a gusseted bottom bag with diagonal heat seals and a sine wave handle. The Humphrey, U.S. Pat. No. 4,764,030, shows serrated bags on a roll but no discharge or filling valve. 
     The Olesen, U.S. Pat. No. 4,881,825, discusses both a filling valve and a discharge valve and a “block” style bottom and top, formed by folding and overlapping the ends of an open tube onto itself much like gift wrapping a box but tucking the sides inwardly and then folding the paper onto itself. See  FIG. 10 , for example. The discharge valve is for the purpose of pouring product out of the bag and no details are shown of the charging features in Olesen&#39;s bag. 
     The Beer, U.S. Pat. No. 4,913,561, shows what appears to be a valve on the upper left corner of the bag but rather than that, it is a heat seal which is intended to allow the bag to square once it is filled with product. 
     The Gelbard, U.S. Pat. No. 4,943,167, shows a side gusseted T-shirt bag made three across at one time and involves the continuous slitting and heat sealing of one tube longitudinally into three longitudinal tubes, post gusseting and heat sealing to create a top and bottom of the bag. 
     The Mundus, U.S. Pat. No. 4,959,114, shows a method which includes feeding flat sheet roll stock, folding it over into two, post gusseting it and sealing it into gusseted tubing with a longitudinal heat seal and then trimming off the excess. 
     The Wood, U.S. Pat. No. 5,165,799; the Gebhardt, U.S. Pat. No. 5,676,467; the Schoeler, U.S. Pat. No. 5,862,652; the Daniels, et al., Re.36,876; the Beer, U.S. Pat. No. 6,213,645; the Angless, U.S. Pat. No. 6,254,520; the Totani, Pub. U.S. 2001/0002938, published Jul. 7, 2001; and the Interpoly Limited U.K. Patent Application GB 2 226 541A, published Apr. 7, 1990, all show gusseted bags, gusseted T-shirt bags, laminated film structure gusseted bags, trifolded bags, post-bag making, and a separate bottom panel system sealed into a tube on four sides that shows an accordion type bag. None of these latter patents have filling systems. 
     It is a primary object of the present invention to ameliorate the problems noted above in prior art chargeable bags. 
     SUMMARY OF THE PRESENT INVENTION 
     In accordance with the present invention, a side gusseted poly bag with a filling valve and its method of manufacture are provided including a tubular body with opposed side gussets defining front and rear panels, and a filling valve formed by folding the front and rear panels with the interconnecting gusset portion at one corner of the bag inwardly into the bag forming a filling panel, and thereafter simultaneously heat sealing the top edges of the front and rear panels with the top edges of the filling panel forming a filling tube and valve that closes itself under the force of material as it rises in the bag. 
     Considerable material savings are achieved by utilizing portions of the front and rear panels and interconnecting gusset portion to form portions of the filling tube. The remaining portions of the filling tube are formed by an “L” shaped integral extension of the front and rear panels and their interconnecting gusset. Alternatively, the extension portions could be a separate piece of material heat sealed to the upper edges of the panels and gusset at the corner. The integral extension embodiment has some material waste because it extends only about 30% of the width of the gusseted web in manufacture. But it saves labor because there is no heat sealing of the separate piece to the preform, which is an additional step. On the other hand, the separate piece method, while requiring an additional step, has no material waste. Either embodiment may be best for a particular application, but the integral extension embodiment is preferred and the one depicted in the present drawings. 
     Because the filling tube is connected completely around the filling opening, which is diagonally oriented, the rise of material in the bag very effectively closes the filling tube over the opening thereby sealing the bag with no further effort. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of the present gusseted poly bag filled with material; 
         FIG. 2  is a plan view of a partly filled poly bag with a filling tube inserted into the valve, discharging material into the bag; 
         FIG. 3  is a partly fragmented view similar to  FIG. 2 , with the bag completely filled; 
         FIG. 4  is a partly fragmented view of the bag similar to  FIGS. 2 and 3 , illustrating the sealing of the filling opening; 
         FIG. 5  is a front view of the bag preform showing the proportional sizes of the L-shaped preform extension; 
         FIG. 6  is a perspective fragmentary view of the preform illustrated in  FIG. 5 , with the bag partly expanded and the relevant panels making up the valve being numbered from  1  to  8 , and the front and rear panels being numbered  9  and  10  respectively; 
         FIG. 7  is a downward side perspective from the right side of the partly expanded bag preform illustrating an intermediate position of the panels as they are folded inwardly into the bag; 
         FIG. 8  is a fragmented right downward perspective illustrating the numbered panels of the extension and the corner of the preform below the extension folded further inwardly into the bag; 
         FIG. 9  is a top view of the positions of the panels as folded in  FIG. 8 ; 
         FIG. 10  is a top view with the panels folded further inwardly from the positions illustrated in  FIG. 9 ; 
         FIG. 11  is a top perspective with the panels folded to their final position before heat sealing, and; 
         FIG. 12  is a front fragmentary plan view of the heat sealed completed bag with panel  9  fragmented away so that the filling tube can be seen; 
         FIG. 13  is a reverse view of  FIG. 12 , illustrating a view looking forwardly of the corner of the bag with the opening of panel  10  removed; i.e., looking toward panel  9 ; 
         FIG. 14  is a perspective view of a filled bag; 
         FIGS. 15 and 16  are depictions of a tubular web being fed and cut according to the present method; 
         FIG. 17  is a cross-section taken through line  17 — 17  of  FIG. 3 ; and, 
         FIG. 18  is a cross-section along line  12 — 12  of  FIG. 2 , showing the bottom of the filling tube and the gusset including panels  4  and  5 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to the drawings, and particularly  FIGS. 1 to 10 , a side gusseted poly bag  11  is illustrated constructed of a thin tubular thermoplastic material having a thickness on the order of 3 to 6 mils. At the outset, it should be noted because of the visual complexity of understanding the various folds in constructing the present bag  11 , that various panels that are defined by fold lines have been illustrated in the drawings with encircled numbers such as those shown in  FIGS. 6 ,  7 ,  8 , and  9 . Each of these panels is defined by a plurality of enclosed fold lines and permit the reader to follow the sequence of folding from  FIG. 6  to  FIGS. 12 and 13 . These encircled numbers are not to be confused with the uncircled reference numerals in the various Figures. 
     It should be understood that the perspective view of  FIG. 1  represents a filled container. As seen in  FIG. 5  initially, which illustrates a preform  12  of the present container, it is seen to include a front panel  13 , a rear panel  14  shown in  FIG. 2 , and side gussets  15  and  16 , and an upward extension  17  that includes a front panel portion  18 , a rear panel portion  19  shown in  FIG. 16 , and a side gusset portion  20  shown in both  FIGS. 5 and 16 . 
     The extension  17 , when properly folded and heat sealed, becomes the tubular valve  24  shown in  FIGS. 2 and 4 . Valve  24  is a filling tube and valve which receives a material discharge tube  25  shown inserted into the valve in  FIG. 2  for charging the poly bag  11  with various materials. As will appear more clearly hereinafter as the bag fills, the tube  24  collapses against bag filling opening  27 , as shown in  FIG. 4 . 
     The bottom of the bag is heat sealed at  28 , as shown in  FIGS. 2 to 4 , and that heat seal includes not only the front and back panels  13  and  14 , as shown in  FIG. 17 , but also the side gussets  15  and  16 , also shown in  FIG. 17 . The top of the bag is heat sealed at  30 , which includes not only the front panel  13  and rear panel  14 , as shown in  FIG. 18 , but also the upper edges of the gusset  15  and the upper edges of the valve  24 , as seen in  FIG. 18  so that the entire upper configuration of the bag  11  is heat sealed together in a single heat seal  13 . 
       FIG. 6  illustrates the preform  12  in  FIG. 5  with the various panels numbered and encircled to achieve an understanding of the folding and formation of the valve  24 . Panel  9  circled is simply front panel  13  and panel  10  circled is rear panel  14 . Panel portion  1  circled is the front panel portion  18  and panel  8  circled is the rear panel portion  19 . Panel portion  1  circled is defined by a diagonal fold line  32  and rear panel  19  is defined by a co-linear unnumbered fold line. Panel  2  circled is defined by vertical gusset line  33  and fold lines  34  and  35 . Triangular panel  4  circled is defined by fold line  34 , fold line  36 , and gusset line  33 . Adjacent triangular panel  6  circled is defined by fold line  36 , vertical gusset fold line  33 , and diagonal fold line  37 . Panels  3 ,  6  and  7  circled mirror panels  2 ,  4  and  6  in the gusset  16  and gusset extension  20 . 
     The preform  12  is partly expanded in  FIG. 6 , and the explanation of folding the extension and the upper portions of the gusset  16 , which includes panels  6  and  7 , will be clearer with reference to  FIGS. 7 ,  8 ,  9 ,  10  and  11 . Note initially that fold line  32 , as seen in  FIGS. 5 and 6 , extends diagonally downwardly from upper edges  40  of the preform panels  13  and  14 , so that fold line  36 , as seen in  FIG. 5 , is substantially below the upper edges  40  of the panels  13  and  14 . 
     It should be understood with reference to  FIG. 6 , that all of the encircled numbered panels  1  to  10  in  FIG. 6 , are in a vertical plane, as shown in that FIG., and that the fold lines  32 ,  33 ,  34 ,  35  and  36 , are creased in a direction to facilitate the folding pattern described with reference to  FIGS. 7 ,  8 ,  9 ,  10  and  11 . The mechanism and mechanical element and the folding and creasing elements necessary to achieve these functions have individually been within the bag manufacture art for many years, but as of the present date, a completely automated machine for achieving this result, the fold lines, and the folding operations, has not been devised, but the description of these elements is adequately contained in this specification because the fold lines and folding can be produced manually. 
     Referring to the sequence of folding the extension  17  shown in  FIG. 6  into the valve  24  illustrated in  FIGS. 2 and 11 , will be described with reference to  FIGS. 7 ,  8 ,  9  and  10 . As seen initially in  FIGS. 6 ,  7 ,  8  and  9 , the extension beginning with fold line  33 , is folded inwardly into the bag between the front panel  13  and the rear panel  14 , as shown in  FIG. 7 , which is a right side view where the extension  17  is not as yet coplanar with the top edges  40  in the front panel  13  and the rear panel  14 . In this position, the triangular panels  4  and  5 , which were in the upper part of the gusset  16 , have been folded inwardly and downwardly so that they are not visible from the right side view of  FIG. 7 , because they are behind the panels  6  and  7 , as shown in  FIG. 7 . The same view is illustrated in  FIG. 8 , which is a top view where the panels  4  and  5  are now visible and they cover the panels  6  and  7  illustrated in  FIG. 7 . The panels  1  and  8 , as shown in  FIG. 8 , begin to form a trough with the upper gusset panel portions  2  and  3 . 
     Further lowering of the panels  1 ,  2 ,  3  and  8  into the bag is illustrated in  FIGS. 9 and 10 , where the vertical upper edge  42  of the encircled panel  1 , and the vertical edge  43  in the panel  8  in the preform  12  rotate downwardly as shown in  FIG. 10 , toward a line co-linear with forward and rear panel upper edges  40  as shown in  FIGS. 10 and 11 . 
     This positions panels  1 ,  2  and  8  into a trough-like configuration defining a U-shaped panel  46  that will become the filling valve  24  when completed. 
     The upper edges  42  and  43  of the panels  1  and  8  are then brought together as shown in  FIG. 11 . 
     The configuration of the resulting filling panel  46  can be seen in  FIGS. 12 and 13 . In  FIG. 12 , which is a front view, the panel  13  has been removed to illustrate the filling panel  46 , which consists of the panel  8 , which has upper edge  43  co-linear with the upper edge  40  of panel  10 , and panel  4  forming a gusset with panel  5  against panels  6  and  7 . Gusset fold line  50  between panels  3  and  8  becomes irrelevant at this point because the filling panel  46  is simply a loop defined by panels  8 ,  3 ,  1  and  2 . 
     As shown in  FIG. 13 , which is a view from the rear looking forward of bag  11  with the rear panel  10  removed, the preform filling tube panel is shown to include the panels  1  and  2 , and the gusset panel  5 , which seats over the top of and hides the gusset panel  7  shown in  FIGS. 6 and 9 . 
     The filling opening is referenced in  FIGS. 12 and 13 , again by the reference numeral  27  indicated in  FIG. 4 . 
     After the completion of the preform  12  illustrated in  FIG. 11 , the bag is heat-sealed at  30  as illustrated in  FIGS. 1 ,  2  and  3 , to complete the bag  11  as shown in  FIG. 14 , which is depicted in its filled condition. 
       FIG. 18  is a cross section taken generally along line  18 — 18  of  FIG. 2  looking upwardly in the bag toward the valve  24 . Note that the section of  FIG. 18  is taken through the gusset formed by the collapsing of panels  4  and  5  against the interior surfaces of panels  6  and  7 , and they are so depicted in  FIG. 18 . Since  FIG. 18  is an upward view toward the bottom of the panel  46 , the encircled numbered panels  2  and  3  are shown which hide the remaining portions of the filling panel  46  defined by panels  1  and  8  illustrated in  FIGS. 12 and 13  respectively. 
     As seen in  FIGS. 15 and 16 , the present method is practiced by a web-fed continuous process, and the web  60  is illustrated in  FIG. 16  very schematically and emanates from a tubular roll of thermoplastic material having the appropriate dimensional configurations. Thereafter, as the material is fed from the web, suitable folding bars (not shown) form the side gussets  15  and  16 . Thereafter, the extension  17  is formed by cutting away the material illustrated at  62  in  FIG. 15 , thereby forming the preform  12  illustrated in  FIG. 16 , and also illustrated in  FIG. 5 . Thereafter, the various fold lines are formed during the folding process illustrated in sequence from  FIG. 6  to  FIGS. 7 ,  8 ,  9 ,  10  and  11 , and thereafter, the heat-seal  30  is effected which not only heat-seals the upper edges  40  of front and rear panels  13  and  14 , but also the upper edges  42  and  43  of the panels  1  and  8 , completing the filling valve  24  in accordance with the present design.