US3047205A - Bag closure - Google Patents

Description

July 31, 1962 SOUTHARD 3,047,205

BAG CLOSURE Filed NOV. 20, 1959 INVENTOR: gberf H.5ouf/1ard W MW ATTORNEYS 3,047,205 BAG CLOSURE Hubert H. Southard, 740 Palm Ave., Seaside, Calif. Filed Nov. 20, 1959, Ser. No. 854,412 1 Claim. (Cl. 229--62) This invention relates to bag containers and more particularly involves a bag construction and method for closing same.

Conventional bag constructions and closure methods very often include the step of stitching a filler opening closed. When such bags are used for granular materials, particular caution must be observed to prevent leakage. It has been noted that such leakage as may occur does not take place through the stitch holes but rather between the stitches. To prevent such leakage it is conventional to employ a binding tape over and across the opening either before or after stitching. However, the cost of applying such a tape to the bag is an expensive proposition, requiring no less additional expense than the cost of the tape. Also, while the manual application of such a tape is simple enough when the bag is fiat, as where a bottom is formed, it is far more diflicult to apply the tape to a filled bag since the contents tend to bulge the sides and twist the opening into an ellipse. Accordingly, if the tape is manually applied an experienced operator is almost a necessity. Because of the difliculty in applying tape to a filled bag, special machines are more commonly utilized, and this, of course, involves an expenditure for capital investment.

It may be noted that in some applications the use of binding tape is not an absolute necessity. However, in such instances the stitching must be closely spaced to prevent leakage. The present invention does not require close stitching and therefore has the advantage of allowing almost double the distance between stitches, resulting in half the required number of stitches (a saving in thread) and permitting a decrease in the required operating speed of the stitching needle. The importance of the latter result will be clear to those persons skilled in the art who appreciate that stitching needles must be air cooled to reduce frictional heating. Thus, where fewer stitches are made in the same period of time the needle can be worked at a slower rate, thereby increasing the life of the needlel In the alternative, it would be possible to almost double the linear speed of the bags through the stitching machine without further burdening the needle or its operating machinery.

It is of particular advantage to use as few stitches in closing a bag-opening as possible, since each stitch hole will produce a weakness in the bag material, thereby impairing the inherent strength of the bag. Since the bag construction and closure method hereinafter described will require a minimum of stitches (and stitch holes), such a bag will possess a superior strength characteristic compared to those bags which must use a greater number of stitches.

In view of the above advantages which are contemplated, it is one object of this invention to provide a bag container for granular material and the like having two parallel but laterally extensible side walls, said side walls having top edge portions forming a filler opening into said bag, one of said walls including a top flap portion extending beyond the top edge of said other side wall and adapted to be folded back upon itself through said opening and into said bag; said bag then being adapted for filling with a granular material to a level slightly below the depending edge of said top flap portion and sealed by stitching across the width of said opening through said side walls and said interposed top flap portion; whereby upon sealing said bag a substantial portion 3,047,205 Patented July 31, 1962 of said flap will lie in parallel adjacency with the inner surface of the opposite side wall, granular material tending to be lodged in the crease of the fold between said one side wall and its said side flap portion.

Another object is to provide a method for filling and sealing a bag having side walls forming a top opening,

one of said side walls including a projecting top flap portion along one side edge of said opening, comprising the steps: folding said top flap portion back upon itself through said opening and into said bag, filling said bag with granular material to a level slightly below the depending edge of said top flap portion, then stitching across the width of said opening through said side wall and said interposed top flap portion; whereby upon sealing said bag a substantial portion of said flap will lie in parallel adjacency with the inner surface of the opposite side wall, granular material tending to be lodged in the crease of the fold between said one side wall and its said side flap portion.

Other objects of this invention will become apparent to those skilled in the art in view of the drawings and the following description.

In the drawings forming a part of this application and in which like parts are identified by like reference numerals throughout the same,

FIG. 1 is a perspective view of a portion of one embodiment of a bag product contemplated by this invention.

FIG. 2 is a longitudinal section taken on lines 2-2 of FIG. 1.

FIG. 3 is a longitudinal section of the embodiment of FIG. 1 having its flap portion folded preparatory to filling.

FIG. 4 is another perspective view of the embodiment of FIG. 1 showing the bag filled and stitched closed.

FIG. 5 is a top plan view looking along lines 5-5 of FIG. 4.

FIG. 6 is a section taken on lines 6-6 of FIG. 4.

FIG. 7 is a longitudinal section of a bag which has been formed, filled and sealed in accordance with the disclosure of this invention.

FIG. 8 is a partial top plan View similar to that of FIG. 5 but showing a bag which has its flap portion folded across the near infold.

Referring to the drawings there is shown a preferred embodiment of bag construction, said bag including parallel front and back side walls 10 and 11, respectively. Walls 10 and 11 are integrally formed from a single sheet of three-ply paper, the side edges of each wall being joined by accordion infolds 12 and 13, as best shown in FIG. 1. The top edge portions of the side walls 10 and 11 provide a filler opening 14 into the bag, wall 11 including a flap portion 15 that projects substantially beyond the top edge 16 of side wall 10-. In a preferred construction, the bottom edge portions of side walls 10 and 11 are formed the same as the top edge portions, but are initially sealed to form a bag. In forming the bottom seal, the bottom flap portion (similar to flap 15) is folded back upon itself within the accordion fold 12-. Then the end is sealed by stitching through the bottom edges of the side walls and the interposed flap.

Preparatory to filling the bag, top fiap portion 15 is folded back upon itself through opening 14, as shown in FIG. 3. The bag is then filled with aggregate or granular material to a level slightly below the lower depending edge 17 of flap 15. The top edge portions of walls 10 and 11 are then pinched together, and the opening 16 is sealed by stitching through the walls and the interposed flap 15 as illustrated in FIG. 6. Upon pinching the side walls together, there is a tendency for the flap to be positioned in parallel adjacency with the inner surface of the opposite side wall. Then, when the bag is placed on its side, as shown in FIG. 7, the granular 3 material is forced between the fiap and its side wall. It may be noted that the same result is produced along the edges of the bottom opening when the bag is filled.

Since only narrow, tortuous passages exist from the inside of the container to the openings at the edge portions of the side walls, almost none of the aggregate or granular' materials finds its way to the stitching.

FIG. 8 illustrates an alternative method of folding flap portion 15 into the bag preparatory to filling. It will be noted that the flap here shown encloses the entire accordion fold. Since filling of the bag will tend to expand its opening, should the bag be thus folded, it may be necessary to hold the flap in place proximate each infold. But the bag closure principle and method of operation is the same as described above.

Although a needle-thread type of stitching is shown, it will be evident that wire material, such as a staple, could also be used for stitching the openings closed. It is also contemplated that a valve device such as is commonly used for filling sewn bags, could be added at one or both ends of the bag.

In view of the above description it should be apparent that various changes may be made in the size, shape and formation of certain portions of a bag without departing from the spirit of this invention or the scope of the at- 25 tached claim, and each of such changes is contemplated. Having thus described my invention, what I claim and desire to secure by Letters Patent is:

A bag container for granular material and the like having two parallel but laterally extensible side walls and end walls having accordion infolds, said side walls having top and bottom edges forming top and bottom openings into said bag, one of said side walls including top and bottom flap portions extending across said top and bottom edges thereof, each of said flap portions being folded back upon itself into said bag over said accordion infolds; means stitching across the width of said bottom opening, said means piercing said side walls and said interposed bottom flap portion; said bag then being adapted for filling with a granular-like material to a level slightly below the depending edge of said top flap portion and sealed by stitching across the width of said top opening through said side walls and said interposed top flap portion; whereby upon sealing said bag, a substantial portion of said flaps will lie in parallel adjacency with the inner surface of the opposite side wall, granular material tending to be lodged in the crease of each fold between said one side wall and its said top and bottom fiap portions.

References Cited in the file of this patent UNITED STATES PATENTS

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