US1917975A - Paper bag - Google Patents

Description

R. w. JAITE July 11, 1933."

SAFER BAG Filed Oct. 4, 1930 2 Sheets-Sheet 2 FIE-5' PIE-4 INVENTOR Ray w- JWWE ATTORNEYs Patented July 11, 1933 ROY W. JAITE, OF LAKEWOOD, OHIO PAPER nee Application filed October 4, 1930. Serial No. 486,404.

My invention relates to paper bags, and is an lmprovement pertaining more particularly to paper bags in which the opposite ends are closed by a sewed seam or equivalent means, such for example, as in the so-called valve type in which the body of the bag iscomposed of a multiple or plural number of flat tubes or tubular plies of paper, and provided with a self-closing valve in one angular corner. Such bags are usually plicated or formed with pleated folds at their longitudinal edges, and closed at both ends, except for the valve opening in one corner. To close such ends the general practice is to sew the corresponding ends of the plies of paper together, and also to paste a binding strip around the end edges. Each tubular ply of paper also possesses a pasted longitudinal overlapping seam, the ends of which are trav- 0 ersed by stitches and united together and to other overlapping plies in sewing operations. Also in making the bag, the seam in each successive tube is usually placed in laterally olfset relation to the seams in the other tubes, 5 and furthermore, all the seams are located on the same side or in the same side wall of the bag. Accordingly, the bag possesses more resistance to stretch and pull longitudinally n in one side wall (the seamed side) than in the other or unseamed side. It also follows that the bag is not of uniform thickness across each end where stitched or sewed on a straight line transverselyof the bag. That is, the 5 sewed stitches which extend across the ends of the bag pass through successive areas of different thickness, inasmuch as each tube in the bag is of double thickness where seamed and only of single thickness elsewhere, excepting at the valve folds. In that connection be it known that the sewing needle passes through the thicker and thinner areas suecessively and punctures the paper at close intervals, and that the tension in the threads and on the paper may vary owing to the unequal thickness of the bag along the sewed line.

For practical usages, paper bags of this type are of substantial size, say approximately fifteen inches wide and twenty-six long in the flat. They are. used extensively for transporting powdered materials, for example, cement, and hold about ninety-four pounds net. To carry that weight, these bags must be made of relatively tough paper and embody a sufficient number of tubular plies to p protect the goods therein and withstand breakage and rupture, especially when the bags are being filled, and when picked up and handled. Owing to frequent breakage, and loss of contents of such bags, the trade as present demands that such bags shall embed" at least five tubular plies of paper of given quality and strength. However, different paper and a lesser number of plies of paper would suffice to make an acceptable bag, providing the bag would not tear or burst open, especially on its unseamed side and/or in the region of the sewed overlapping seams. My object in general is to provide a bag of the same or a lesser number of plies than as used 7 and required heretofore, which will be stronger and more secure, and overcome the known dangers and objections in breakage and rupture in that type of bag, substantially as set forth herein. In the accompanying drawings, Fig. 1 is a side elevation, and'Fig. 2 an edge view, on a reduced scale, of a paper bag embodying my invention. Fig. 3 is a cross sectional view of the bag, the scale and proportions 30 being changed and enlarged from the other figures to better delineate the internal construction of the bag. Figs. 4 and 5, are obverse and reverseviews of the same bag, portions of the successive tubular plies being 35 broken away in stepped relation to show the internal construction within the opposite sides of the bag. Figs. 6 and 7 are diagrammaticviews, corresponding to cross sectional views on lines 6-6 and 7.7 of Figs. 4 and 5, respectively. Figs. 8 is a perspective view of'a sectional portion of a bag embodying a modified form of the invention, only two tubular plies being shown to more clearly illustrate the inventive concept. As a preliminary, it should be understood that in manufacturing multi-ply bags of the kind disclosed in the drawings, a series of sheets or strips of paper are fed through a tubing machine and creased or folded to form a multi-ply tube A having pleats or inwardly-extending folds 2 in the longitudinal edge portions thereof. The sheets are fed into the machine in superposed relation with their parallel edges offset or in stepped relation so that when the sheets are jointly folded to produce a flat plicated tubular body the parallel edge portions of each sheet will overlap and form longitudinal seams 3. Paste is also applied to the paper along the edge thereof so that the overlapping parts of the seam in each sheet are united together. The tubular product thus embodies a multiple number of seamed tubes sleeved together with the pasted seams 3 in the respective tubes extending longitudinally in parallel colateral relation or side by side, all the seams being on the same side, that is, in the same side wall of the multi-ply tube. For future convenience in establishing the relationship of different parts in the bag, the seamed side Wall will be referred to herein as the rear tube between the outer tube and the inner tubes.

In any case, when the tubular product is severed into given lengths one plicated corner thereof is folded inwardly to provide a valve 5 in the form of an open pocket or filling opening 5, the inturned walls of which extend a given distance inwardly on lines substantially parallel with the transverse end edge of the sleeved tubes. The end edges of the tubes are covered and enclosed by a binding strip 6 of paper or other material which preferably is secured in place upon both sides of the outer tube by a paste or adhesive. These bound portions are then stitched or sewed together on a straight line parallel with the end edges, as represented by the line 7, using chain stitch or other suitable sewing stitches. -However, before the binder strips are applied and sewing of the ends eifected,.one or more re-enforcing strips 8 of paper or other material are placed lengthwise upon or within the plain unseamed side or front wall of the sleeved tubes. The length of the strip or strips 8 corresponds to the lengthof the tubes so that the opposite ends thereof will be stitched or sewed to the corresponding ends of all the tubes. The width of the strip or strips 8 is more or less optional, but preferably a plurality of narrow strips are employed, and these strips placed parallel with and opposite the seams 3 on the reverse side of the tubular assembly. A plural number of strips v8 may be used in spaced relation between the opposing walls of two tubes as shown in Fig. 8, or these strips may be inserted between the respective walls of more than two tubes. Preferably, when two or more strips 8 are used, they are placed in overlapping relation between the plain unpleted and the completed bags are filled and put into use. Thus, instead of having a bag in which one side Wall is weaker than the other, the body of the bag possesses the same or substantially the same resistance to tensile strains or stresses on both sides, and the pulling and separating strains on the perforated lines of stitches at the opposie ends of the bag are distributed more or less equally to both side walls of the bag. Appropriately, it should be understood that valve bags of this type are filled by suspending them upon spouts introduced into the valvular opening or pocket 5; and that the weight of the material introduced into the bag places a considerable strain in a localized area or part of the sewed seam across the upper end of the bag, whereupon the plain unsealned front wall of the bag frequently tears or weakens in that region of the seam. The Weakness is not always manifest to the eye when the bag is full and first handled, but later when the bag is shipped and transported and subjected to buckling and bending stresses in lifting it then the walls of the bag may rip or burst open. The incorporated strips 8 supplement and strengthen the front unsean'ied wall of the bag in much the same manner as the overlapping pasted seams in the rear wall, and the pull on both sides of the sewed and hemmed ends of the bag are substantially equalized. The re-enforeing strips 8 may also be pasted to the tubes in part or at full length, but pasting of the opposite ends of the strips to the corresponding ends of the tubes has been found to be satisfactory in practice. Pasting of the strips to the tubes, either full length of the strip or at opposite ends of the strips, defin1tely fixes them in desired relation to the seams n the bag; and the making of the bag, including the sewing operations, may proceed rap dly without displacing the strips or changing their straight alignment with each other and the seams in the bag. Preferably, the strips are all interposed between the outer and inner tube walls and not exposed to view on the exterior of the bag, but a strlp could be pasted lengthwise upon the outer face of the unseamed front wall of the bag to simulate' a seam, especially if this 1 face. A corresponding strip might also be pasted upon the inside of the inner tube toeflect in part the results sought by my invention, but I prefer to. enclose the supplemental strips between the respective plies of the bag. However, I desire to include such and similar modifications and changes as these and other equivalent ways and means 0 strengthening paper bags of the described type, or similar bags in which the ends are closed by sewing or otherwise, providing the prior art and practices permit. Nor do I wish to limit myself to the use of any definite number or precise arrangement of re-enforcing sheets or strips in the bag, nor to a definite number of plies or sleeved tubes, inasmuch as the invention considered in its broadest aspects may be modified considerably without departing materially from the inventive concept.

In manufacturing such bags the strips 8 may be fed together with the several sheets i of paper through the tubing machine, and

. the paso applied and the several sheets or plies folded and severed concurrently with the strips to provide a re-enforced multi-ply tubular body of the requisite length from which to make a bag. Also, the strips may be incorporated between-the separate plies with the .whole strip or only the opposite ends of the strips pasted to the end portions of the tubes, prior to severing the tubular product into tie lengths required to make the bags. The tucking of the valve and the binding and sewing operations are performed subsequently in another machine or in separate machines to which the multi-ply tubular bodies are fed singly and successively.

What I claim is:

1. A paper bag, having its opposite ends sewed shut and formed with an overlapping seam extending longitudinally in one side wall, and a re-enforcement strip extending lengthwise of the opposite side wall and sewed at its ends to the corresponding ends of both walls.

2. A paper bag, having its opposite ends sewed shut, one side wall having a longitudinal seam and the opposite side wall being unseamed, and a re-enforcement strip for the unseamed side wall of the bag aflixed at its opposite ends to the sewed ends of the bag in the region of the seam.

3. A paper bag, comprising a plurality of seamed paper tubes sleeved together, the seams in the respective tubes being arranged in one side of the bag in .ofi'set relation, and a plurality of re-enforcing strips arranged in the opposite side wall of said bag opposite said seams and having their ends stitched to the corresponding ends of the tubes;

4. A paper bag, comprising a plurality of seamed paper tubes so sleeved together that their seams are arranged at one side of the bag and stitched shut at each end, and a supplemental flat strip of paper interposed between the seamless walls of two of said paper tubes and extending to the opposite ends of said bagand seamed thereto by said stitches.

5. A valve bag, comprising a plurality of seamed flat pleated paper tubes so sleeved together that theirseams are located at one side of the bag and sewed shut together at their opposite ends and formed with a filling opening and valve in one corner thereof, and a plural number of flat strips of paper interposed between the respective seamless walls oi said tube and sewed within the ends there- 0 6'. A paper bag, comprising a plurality of flat pleated paper tubes sleeved together, said tubes having overlapping seams extending lengthwise thereof, all said seams being in one side wall of the bag, the other side wall of the bag having strips of paper interposed between the tubes, and the corresponding ends of the tubes and strips being sewed together transversely of the bag.

7 A paper bag, comprising a plurality of sleeved tubes having seams extending lengthwise thereof, all said seams being arranged in an overlapping relation in one side wall of the bag and re-enforcement strips incorporated lengthwise in the opposite side wall of said bag, said strips being arranged in overlapping relation with respect to each other and sewed to the opposite ends of said bag by stitches extending across the ends ROY W. J AITE.

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