US2149872A - Bag and method of making same - Google Patents

Description

March 7, 1939. D. SCHMIDT 2,149,872

BAG AND METHOD OF MKING SAME Filed Nov. 17, 1938 INVENTOR Sc/M/n 7- ATTORNEYS Patented Man 7,V 1939 vUNITED /s'riiliss'v PATENT or-'Flciaz Dobeckmun Company, poration of Ohio Cleveland, Ohio, a cor- App'ueatien November 17, 193s, serial No. 241,003

' 13 claims. (ci. 22e-5s)l t This invention relates to an improvementl in bags and to the methodof making the improved bag and particularly to a bag having an improved vbottom construction and the method of making the same.

Heretofore, bags made from webs or sheet ma-I terial, such as paper, 'Cellophane, or like cellu` lose films, and similar materials, have been classiable as either pinch bottom bags or at bottom bags, according to the bottom construction, of the-bags.

Pinch bottom bags are simple in construction, comprising a tubular body having an end thereof folded back and, secured to the body of the bag to form the bottom. The advantages of such bags are that they are simple in construction and may be cheaply and rapidly manufactured on relatively inexpensive machines. The disadvantages of such bags are that the volume is relatively small, the bottoms are Weak, substantially the entire load of the contents of the bag being carried by the adhesive which secures the bottom fold to the bag body, and the bottom of the bag when filled is not a flat surface, so that lled bags will not maintain themselves in an upright position. Other disadvantages are that the bags are rdilcult to open up and cannot be used in automatic bag filling machinery. The volume of a pinch bottom bag may be increasedby forming it from a pleated tube so that a square bag is formed, as, for. example, see the U. S. patent to Schmidt, No. 2,074,992. Such square bags are easier to open than the'ordinary ilat bag, but otherwise possess the disadvantages characteristie of all pinch bottom bags.

Flat bottom .bags may be of the type known as. Satchel bottom bags or ofthe type known as automatic bags, also called coffee bags. Satchel bottom bags, such as the bag disclosed in the U. S. patent to Schmidt, No. 2,074,277, are usually formed from a flat tube of sheet material'. In making such bags, the one end of the tube is opened up and folded or toggled back against the body of the bag. The toggled end portion .is then interfolded and adhered to form a rbottom element which is hinged to the body of the bag. The advantages of such a bag are that, due to the flat bottom element, the volume is large and filled bags'will maintain themselves in an upright position. The disadvantages are that the machinery for making them is necessarily complicated, expensive, and comparatively slow in operation, the bags are diilicult to open, and tend to assume a cylindrical shape when filled. An- -otherdlsadvantage-is that several creas-s formed in the bag seriously weaken the structure, especially at points where the creases converge. A further disadvantage is that the unopened bags are bulky and are comparatively expensive to ship.

The automatic bags are made from a pleated tube in `substantially the same way that the satchel bottom bags are made, except that an additional crease or crimp must be made across the body of the bag above the toggled bottom element. "Automatic bags are easily opened and tend to retain a prismatic shape when lled, and thus are adaptable for use in automatic bag filling machinery. Otherwise the automatidbags possess all the disadvantages of Satchel bottom bags.

It is the object of this invention to produce a bag having all of the advantages of the bags described above and none of the disadvantages.-

Specifically, it is the object of this invention to produce a bag which can be cheaply and rapidly A action,\ and which has a strong iiat bottom. A

further" object of this invention is to produce a bag having no sharp creases at the junction of the w'alls and the bottom and no converging creases in the walls vof the bag.

Still further objects of this invention are to produce a bag which is adapted for use in automatic filling machines and which, when lled, will tend to'retain a prismatic shape.

Other advantages and objects of this invention will be apparent from the following description and from the drawing, in which Fig. 1 is a development of the improved bag;

Fig. 2 is an elevation of the completed bag;

Fig. 3 is a cross section taken along line 3 3 of Fig. 2; l*

Fig. 4 is an isometric view showing the bag partially filled: A

Fig. 5 is another isometric view showing the bag fully lled; and

Fig. 6 is a bottom viewof the lled bag.

As shown in the drawing, in which like reference characters refer to like elements, the bag IIl is formed from a portion of web or sheet material ,Il in ,which the longitudinally extending corner creases I2 and I3 define a front wall Ill having an arcuate recessed upper edge. On either side of the front Wall I 4 are located the side walls I5 and I6 defined by the corner creases I'I and I2 and I8 and I3, respectively. The side Wall I5 is divided into panels I9 and 20 by the pleat crease .2I. Similarly, vthe side wall I6 is divided into y panels 22 and 23i by the pleat crease 24. A back panel 25 is dened between the corner crease I1 and one side edge' of the sheet II.

Similarly, a second back panel 26 is dened be-4 tween the corner crease I8 and the other side edge intersection of the bottom crease 29 and the pleat crease 2| to the corner crease I1 across the lower corner of the side panel I9. Another diagonal strip of adhesive 3I extends upwardly at an angle of 45 from the intersection of the bottom crease 29 and the pleat crease 2l to the corner crease I2 across the lower corner of the side panel 20. Diagonal strips of adhesive 32 and 33 are similarly located with respect to the intersection of the bottom crease 29 and the pleat crease 29, extending across the lower corners of the panels I9 and 20, respectively. I l The strips of adhesive 30, 3I, 32, and 33 may be of any suitable width, but in the preferred form of this invention, theyl extend up to but not over the 45 angles from the intersection of, the pleat creases and the bottom crease. Nor dol they extend beyond the corner creases.

Integral with the front panel I4 along the bottom crease 29 is the bottom tab 35. A band of a'dhesive 36 is usually placed across the end of .the tab 35. l .p Y In the preferred method of making the improvedbag, a web of material is fed olf a roll of stock through ta suitable spot adhesive applying device which prints or otherwise applies the diag'onal bands of adhesive 30, 3|, 32, and 33 to the web of material at suitably spaced intervals. The web on which the diagonal bands of adhesive have been applied is then passed through a suitable tubing device and formed into a tube having corner creases I2, I3, I1, and I8 and reentrant. pleats creased along the Apleat creases 2I and 24. As the web passes through the tubing device, the longitudinal band of adhesive 21 is applied by any suitable means adapted to applya continuous strip of adhesive. The continuous tube may then be passed through a bag forming mechanism, in which the tubing is cut into bag lengths and one end of the bag length is folded along the bottom crease 29 and adhered to the body of the bag by the band of adhesive 36 which adheres the bottom tab 35 to the back wall 38 to form the completed bag shown in Fig. 2. For a more detailed description of the method of forming the bag, reference may be madev ,to the U. S. patent to Schmidt 2,074,992.

The locations and functions of the several bands of adhesive in the completed bag are clearly shown in Fig. 3. Thus, the strip of adhesive 21 joins the back panel to the back panel 26 to formthe back wall 28. The diagonal strip of adhesive 3D adheres the side panel I9 to the back l matic. bags. 'Ihe present bag, however, is automatic in action, as is shown most clearly in Figs. 4 and 5. The top of the present bag may be opened in any convenient manner. As the material which is to be contained in the bag, usually a. pulverulent material, such as coffee, rice, salt, or the like, is poured into the bag, it falls against ,the diagonal seams in the bottom corners of the bag andiagainst the portion of the bottom crease included between the diagonal seams. As shown in Fig. 4, as more material is poured into the bag, the pleated side walls bellow out and space the front andback walls. At the same time, the walls hinge inwardly along the diagonal bottom seams and along lines extending across the walls between the outermost tips of the diagonal seams. This automatic action continues until the filled bag, as illustrated in Fig. 5, comprises a prismatic Astructure having a flatbottom comprised of interfolded wall portions of the unopened bag.

It should be observed that the corner creases I2, I3, I1 and I8 serve to retain the walls of the bag in a prismatic relationship with each other but that at the juncture of the walls and the bottom, no crease exists, Instead, the walls curve inwardly to f orm the bottom. As may be noted from Fig. 1, the only converging' creases present in the bag are located at the intersection of the bottom crease and the corner and pleat creases. It will be seen in Figs. 4, 5, and 6 that all converging creases are located in the bottom of the filled bag at points which are reinforced by at least two other thicknesses of material. The absence of unreiuforced converging creases and the curved, uncreased juncture between the bottom and the walls of the bag greatly increase the strength of the structure. It vwill also -be observed in Fig. 6 that the diagonal strips of adhesive reinforce the bottom of the lled bag and minimizethe load carried by the-band of adhesive 36 not only when the bag is iilled, but also while it is being filled.

It -is apparent that the essence-of this invention lies in forming diagonal seams between the outer walls of the bag and the adjacent panels of the pleated side walls, the seams extending at an angle ofsubstantially 45 from the intersection of the pleat creases to the corner creases. In the preferred form of the invention these seams are formed by bands of adhesive, but it is obvious that to perform the same function of uniting the bottom corners of the front and back walls with the pleated sidewalls, many equivalent. means could be used, such as, for example, heat seals, staples, stitches, clips. creases, crimps, or any other means which will prevent the separation of the Walls along the diagonal seams.

' This improved bag and the method of making it are especiallyadapted for the manufacture of bags from Cellophane or like lms, which material was not adaptable heretofore to the manufacture of automatic bags because of the excessive number of folding and creasing operations in the manufacture of such bags. This invention is not limited to Cellophane" bags, however, but may be used with a variety of other materials, such as paper, cloth, laminated stock, or any other sheet or web material.

In 'the preferred method of manufacturing the improved bags from sheet or web stock, tubing devices are employed. However, it is apparent thatvthe invention may be practiced on other types of bag making machinery.

Preferably a bag made according to this invention is rectangular in cross-section. It is ap- 75.

seam 75 end clonar diagonal seams adhering the'outer andere y 3 parent, however, that this invention may be used corners of the front and back walls to the adi'or any bag which is substantially prismatic in jacent pleated side walls,.said seams extending form and has a substantially polygonal crossoutwardly from the junction of the inner folds section. of said pleats and said end closure, and said iront It is apparent, therefore, that this invention and back walls being adapted to curve inwardly 5 is not limited to thepreerred form disclosed, along iineS extending between the outermost either in whole or in part, but onlyby the appoints of said diagonal seams to forma dat botpended claims. tom for said bag.

What is claimed is: 8. A bag of cellulosic nlm having an automatic i0 1. As an article'of manufacture, a` bagcomaction, comprising a front wall, a back wall and 1c prislng a pleated tube, an end closure for said pleated side walls forming a nat tube, a single tube, and means uniting a panel ofthe pleat to seam pinching the end-o saidtube to form an an adjacent wall of said tube along a line ex. end closure, diagonal seams adhering the outer tending diagonally from the inner fold of said corners of the front andback walls to the ad pleat adjacent said closure to an outer fold of jacent pleated Side Walls, Said seamsextending 15 said pleat' and closing oft the voiume of the bag outwardly from the junction of the inner folds of included between said ,panel and saidadjacent saidpleats and said end closure, said pleated side v side wall below said diagonal line. walls being adapted to bellow outwardly, hinging 2. As an article'of manufacture, a bag comalong Said diagonal SeanlS and curving inwardly prising a pleated tube, a seam extending across along lines extending between the outermost 2o said tube to form an end closure and means points of said diagonal seams to form a at botuniting a panel of the pleat to an adjacent wall tom for said bag. l -r of said tube along a line extending upwardly from 9. A bag of cellulosic'film having an automatic i the intersection of the'inner fold of said pleat action,- compri'sing a front wall, a back wall andV and said seam to the outer fold of said pleat and pleated side walls forming; a lat tube, a single 25 lclosing oli the volume of the bag included beseam pinching the end of Said tube to form an tween said panel and said adjacent sidewall end closure, diagonal'SealnS adhering the outerv below said diagonal line. corners of the front and back walls to the ad- 3. As anarticle or manufacture, a' bag comjacent pleated side walls, said seams extending; prising a. pleated tube, a transverse fold in one outwardly from the junction of the inner folds of 30 end of said tube adhered to the body of the tube said pleats and said end closure, said bag being to form an end closure, vand means to unite a adapted to open up to form a nat-bottomedprispanel of Asaid pleat to an adjacent wall of said matic structure, said front. back, and Side Walls tube along a line extending diagonally from the curving inwardly at the juncture 0f the Walls and inner fold of said pleat at said transverse fold to at bottom of the prlsmatic structure. `35 the outer fold o f said pleat and closing of! the l 10. A method of forming bags having an autolvolume .of the bag""included between said panel matic action, oomprisingthe Steps of applying and said adjacent sidewall below said diagonal short diagonal strips of adhesive to a web of line. sheet material, forming said lweb into a nat 40 4. As an article of manufacture. a bag compleated tube enclosing vsaid strips of adhesive prising a tube having a front wall', a back wall, between the pleats and the unpleated walls of 40 and pleated side walls, said tube being pinched said tube, severing said tube into bag lengths adat one end to form an end closure, and means jacent the location of lSaid diagonal Strips of uniting the inner surfaces of the front and back l adhesive and pinching the Severed end of tbe tube 4; walls of said tube to thefinner surfaces of the adjacent the location of the diagonal strip of 45,

' adjacent pleated side walls along lines extending adhesive to form a' seam extending across said diagonally and upwardly from the innen folds of tube contiguous to .said diagonal strips of adsaidpleats at said end closure to the outer folds hesive. i of said pleats. 11. A method o! forming bags having an auto- 5..A bag comprising a pleated tube of web mamatic action. comprising the steps of applying terial, front, back, and pleated side walls in said pairs of Short Strips of adhesive to a Web, the tube, said tube being folded at...one end to form Strips of adhesive in each pair being applied at an end closure and inner surfaces of the said Substantially right angles t0 eacbotbel and di.- front and back walls of said tube being adhered` agonaliy to the length of the Websiforrnine the to inner surfaces of the said pleated side walls web into, a pleated tube, severing the tube adalong lines extending diagonally outwardly from 'jacent the pairs Aof short Strips of adhesive, and 55 the intersection of the inner lfolds of said pleats folding an end of Said Severed tube to form an and said end closure. end closure. 6. A bag comprising a tube of web material. 12-l In the pr ess of forming a pleated bag,

6 reentrant pleats formed in the sides o! said tube, the Steps 0f adhering the inner Surfaces 0f the 6o y an end portion of said tube folded back against front and back walls-of a pleated tube, to the the body of said tube, a transverse band of ad, inner surfaces of the adjacent panels of .the hesive securing said folded portion to said.tube pleated Side Walls along outwardly divergent.` to form a pinched end closure in said tube, and seams. and folding and adhering an end p0lti'9n strips o! adhesive located within said tube to of'said tube against'the body of the`tube adia- .65

adhere said reentrani; pleats to the unpleated cent the outwardly divergent seams.'y portions of said tube, said strips extending at an 13. In the process of forming 'a pleated bag, angle Vof' 45 to said bottom fold from the inner the steps of forming a pleated'bas body'. forming folds 'or said pleats to the outer folds.. of said an end closure in said bag body and uniting the pleats. outer corners o the inner surfaces of Ithe outer 7. A bag of cellulosic nlm having an automatick wallso! the bag body to the inner surfaces of the 7o action, comprising a front wa1l,'a back wall and panels ot the' odia-cent pleats along diagonal pleated side alls forming a nat tube, agsingle lines' extending outwardly from 'the' junction of ching the end of saidtube to form an the inner folds ofthe pleatsand the end closure.

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