US2330446A - Apparatus for producing bags - Google Patents

Description

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4 Sheets-Sheet 1 T. E. PIAZZE ETAL 'Fil d'se t. 12, 1938 APPARATUS FOR PRODUCING BAGS Sept" 28, 1943.

mvwrons ATTORNEY Sept. 28, 1943.

T. E. PIAZZE ET 1.

APPARATUS FOR PRODUCING BAGS Filed Sept. 12. 1938 4 Sheets-Sheet 2 INVENTORS Sept. 28,1943. T. E. PIAZZE ETAL APPARATUS FOR PRODUCING BAGS Fi1ed Sept.'12, 1938 4 Sheets-Sheet 3 INVENTORS ATTORNEY.

p 1943- T. E. PlAZZE ET AL 2,330,446

APPARATUS FOR PRODUCING BAGS Filed Sept. 12, 1938 4 Sheets-Sheet 4 BY @W I M f% INVENTQRS Patented Sept. 28, 1943 {5,330,446 APPARATUS FOR PRODUCING BAGS Thomas E. Piazze. Milwaukee, and Roy E. Hanson, Wauwatosa, Wis., assignors, by mesne assignments to Simplex Wrapping Machine 00., Oakland, Calif., a corporation of California Application September 12, 1938, Serial No. 229,472

Claims.

Our invention relates generally to improvements in the art of producing containers, and relates particularly to an improved bag and to a method of and apparatus for manufacturing the same.

Generally defined, an object of the invention U:

is to provide a new and useful bag structure, and an improved method of and apparatus for manufacturing such structure from sheet material such as regenerated cellulose film.

In the manufacture of bags from cellulose film or other similar sheet material, considerable difiiculty has heretofore been encountered in producing a tight closure for the bottom of each bag. In some of the prior bags of this type, adhesive such as cement is used to form the longitudinal seams and the transverse bottom seams, while in others the seams are formed by heating the overlapped portions of the sheet material to cause the coacting surface coatings to melt and fuse together. When cement is used, it is impossible with the present commercial methods to form an airtight and moisture proof bag from tubular stock, because the adhesive cannot be applied between the frontand rear walls before the bottom closure fold is made, and for this reason the bottom fold is ordinarily formed with one wall extending beyond the other so as to provide a projecting tongue and to permit cementing of both walls of the fold to type, a ribbon of stock derived from a supply roll, is usually folded longitudinally into tubular formation, and the overlapped edges are thensecured to each other to produce a permanent tube which is subsequently cut into the desired lengths each'of which is finally closedat one end to form a complete bag. When a large number of these bags of the same size are required, it is customary to operate the bag forming machine continuously and at high speed, and the completed bags are stacked into rather compressed bundles preparatory to delivering,

. shipping or storing. Because the sheet matethe adjacent wall of the bag, independently of the other. This usually produces a bag which is not airtight at the bottom because it has slight openings at the ends of the bottom fold. When heat sealing is used, the bottom fold is ordinarily formed and sealed as in the cemented type of bag, or else the bottom fold is cut straight across and folded and subsequently heat sealed by applying pressure and heat to the four superimposed layers of stock. This latter procedure results in the production of bags having diminished holding capacity, because the lower ends of the front and rear Walls have been sealed or attached to each other within the bag enclosure and above the fold line. I

It is therefore one of the primaryobjects of this invention to provide an improved bag formed of cellulose film or similar sheet material and an improved method of makingthe same, wherein the bottom fold may be secured in place and sealed to provide an airtight closure, with- In the manufacture of bags of this general H rial becomes rather brittle with age and when subjected to varying atmospheric conditions, sharp creasing at the opposite sides of the bags frequently causes them to tear at the creases and'seam's, when the bag are distended during loading, thereby entailing considerable waste and loss to the user. The user of such bags may also desireto frequently vary the sizes of the receptacles for different uses, and may only require a relatively small number of one size and larger quantities of other sizes, thus making it desirable for such a user to produce his own bags in'the various required shapes and sizes. Production by the user also assures him of obtaining fresh bags, and eliminates the necessity of stacking and storing the containers in compressed bundl'eswhich tend to disrupt the seams and'to produce sharp creases. In order to insure most economical production of such bags by individual producers, the use of adhesive should preferably be dispensed with, while at the same time permitting the producer to provide tight joints. If such procedure is made possible, the individual bag producer will be in a position to purchase rolls of the bag stock, printed or otherwise decorated in any desired manner, and he may thereafter manufacture bags of any desired size and shape as they are needed.

It is therefore another primary object of this invention to provide an improved method of and apparatus for making bags from a roll of sheet material and in varied amounts and sizes-, either plan or decorated, but in a most economical manner.

Some of the more specific objects of our present invention may be enumeratedas follows:

. To provide a simple and efficient method of making bag-like containers from a continuous ribbon of sheet material such as regenerated cellulose film, and without necessarilyutilizing cementto produce tight seams.

To provide an improved machine for rapidly and economically manufacturing bags of various sizes and shapes, with minimum waste of material.

To provide an improved bag which is airtight and moisture-proof at the bottom, and wherein the bottom! foldli'sioft uniform thickness and. hasits several plies firml'yattached to each other and to an adjacent wall of the bag without de- K stroying the holding capacity of the bag above the bottom fold.

To provide an improved bag structure formed of regenerated cellulose filmand having the. seams thereof heat sealed and crim-pedto produce an airtight container which may-bejreadilyandeconomically manufactured from" a continuous ribbon of sheet material.

To provide an improved machine adapted, to

produce a succession of bags from a continuous provedzmethodfof constructing such bags. and: of

theadetails ofi constructionvand: operation t one type of machine which may be used in the exploitatiom of our; improved method. may be had by 'refenringto the" drawings: accompanying and forming: at partof this specificationewherein like reference. characters-"designatejthe: same or. similar parts: the various views.

Fig;.1ris asiizleelevation: of oneofi the machines for: exploiting our improvedrmethod; some of the simucture'; beingfshown rather diagrammatically, and ithe mechanism being; shownzin actiom in the act 70f. forminga' bottom closure for a: bag;

Fig. 2 is. a fragmentary side elevation of? the bag' end-closing portion of the mechanism; showing the bottom-of a bag being finally sealed Fig; 3': is a fragmentarysideelevation of the stock:-advancing mechanism, showing-the same at the completion of its travel following'withdratval ofiacomp1eted= bag from the forming zone;

Fi'g. 4 is an enlarged top viewof'a' fragment-of the lbngitudinal seamingstructurewhich is con-- fined Within the bagforming tube;

Fig 5 'is a likewiseenlarged transverse vertical section through the-longitudinalseaming mechamsm;

Fig-1 6 isa top view Of-afrag-m'ent ofthabag forming machine, showing the mechanism for forming the longitudinal and transverse' seams, thisviewmorresponding to the position of theelements -in -Fi'gr 31 Fig. '7 is a transverse vertical sectionthrough approximately one' half" of the-machine, looking towardthe cutting and sealing mechanisms Fig: 8* is a fragmentary side view' of' the cutter actuating mechanism in; inactive position;

Fig, 9 is a similar side view of. the cutter mechanism in action.;,.

Fig. 10 is an enlarged fragmentary front view of Fig. 11, taken along the line l3l3 thereof;

Fig. 14 is a plan view of another type of bag having accordion or double folds along the opposite sides thereof;

Fig. l5'is a longitudinal section through the ,bag ofFig- 1e, taken along the line l5-l5 thereof;

Fig. lfi is atransverse section through the bag of Fig. 14, taken along the line 16-16 thereof;

Pig; 1? is an enlarged diagram showing the initial-.stepdn the-improved method of forming a bag; directly: preceding. the'severing of a com-- pleted bag;-

Fist-18% is a similar diagrammatic view showing the position of the forming elements. directly follow-int; thezseverance of a completedzbag from the: tubular stock;

' Fig. 19 isa;similar diagram showing the initial step ofofoldingthe bottom of a subsequentrbag, following the" step: of Fig. 18;

Fig. 20 is a similar-diagrammatic view showing thetnextfoldingl operation for closing the bottom of the 'bagv end;

Fig. 21: is a similar diagrammatic representation. showing the step of the process involving finalfoldihgrofithe bag; end andldirectly prececling thafinal: crimping: andrsealingv ofthe bottom of the-bag;

22; is a; diagrammatic disclosure showing the final; crimping: andasealingq of the bottom of the. bag; and:

Fig:.23;is a; similar diagram: showing the mode off clamping andl' of. advancing the completely sealedf baguafter bottom: closure thereof.

Whileour'inventiorr has been illustrated and described hereirr as: being primarily applicable: to a; method of. and; apparatus for forming rectangular bags: from a ribbon of cellulose'film; it is not the intent to thereby unnecessarily limit the scope; since some: of the' novel features are adapted tobe more generally applied in the manufacture of different types of bags'from different kinds of" material having: characteristics simulating that of cellulose material; The use of specific terms for descriptive purposes, is not to be constructed as an unnecessary limitation, and is resorted to merely in' orderto' clearly describethe invention and'tomake the sameknown to others skilled inthe art.

Since the improved'bag assemblage is animportant featureof'our present invention, it appears desirable to initially describe the several bags-manufactured in accordance with thepresent invention" and which are illustrated in Figs.

,11 to 16 inclusive.

Referring first to Figs. 11 to 1'3, we show therein aform ofbagjembodying the invention which comprises a tubular body 52' having front and rear'port'ions and 86, respectively, and one end of .wh'ich' has been closed by folding over the end part 88'upon the body orwall 86 of the bag along the fold. line 89. 88' above the fold line 89' are secured together and. to. the-wall 8.6.of. the bag. More particularly, according to the improved. method, the bagma- Theseveral plies of the end part terial is first formed into a tube from a supply of sheet "material preferably in roll form by bringing the side edges of the sheet into overlapping'relation and heat sealing them together by'the application of heat and pressure with a longitudinal seam 81, and then the open end of the tube is bentback upon itself at the fold line 89 and the adjacent end plies of the tube are sealed together and to the wall 86 of the tube by crimping 90 and by the simultaneous application of heat or adhesive as will be subsequently explained. While the body has been particularly referred to as having walls, it will be understood that these walls are not necessarily formed by definite fold lines made in the material.

The bag structure shown in Figs. 14 to 16 is substantially similar to that above described except that instead of a plain tube, the side portions of the sheet are creased to provide accordion or bellows portions 93. Otherwise, the structure of the bag and the method of its manufacture is identical with the first form. In this form the tube 52 has front and rear walls 9|,

92, a longitudinal seam 94, and a bottom includ.

ing the end part 95 folded over the wall- 92 along a fold line96 and attached to thiswall by crimping 91 and by the application of heat or adhesive as will be subsequently described.

. Referring to Figs. 1 to 10 inclusive, we have illustrated therein one type of manually operable improved mechanism forfacilitating commercial exploitation of our improved method of produc ing the improved bag structures of Figs. 11 to 16 inclusive, from regenerated cellulose film pro.- vided with a fusible coating. This improved machine or mechanism comprises in general a main elongated frame 25 having atoneend thereof, journals 26 adapted to support a supply roll 21 of thestock or sheet material; brake mechanism 28 cooperable with-the supply roll 21 to frictionallyretard the rotation thereof; guide rollers 29, 3 journalled in the frame 25 for conducting the ribbon 3| of sheet material from the roll 2! in the desired direction; a stationary former plate .32 providing; a fixed elongated table securedto the frame 25 and adapted to convert the ribbon 3| into tubular form with overlapped edge portions as it is advanced along the frame away from the supply roll 21; longitudinal seaming structure including laterally spaced folding rollers33' and a heated and peripherall grooved intervening roller 33 rotatably suspended from an oscillatory arm 36, and coacting through the overlapped edge portions of the ribbon with parallel rods35 secured to the former plate 32 by means of a block 36; a fixed lower support 3'! coacting through the intervening ribbon 3| with the lower face of i the former plate 32, and having a, flexible ended stripper plate 38 movable longitudinally therebeneath; a lower horizontal resiliently supported cutter blade or knife 39 'cooperable with an upper downwardly movable cutter blade or. knife 40 to sever the tubular ribbon 3| into predetermined lengths; a carriage 4| supporting bag clamping mechanism and suspending the same for reciprocation along parallel side rails 42 fixed to the frame 25, and along which the carriage retaining guides 43 are adapted to travel; bag end folding structure including a tucker or folding member 44 mounted for oscillation above the delivery end of the former plate 32, and a combined folding and gripping jaw 45 which is swingably mounted upon the carriage 4| and is cooperable with the member 44 to hold the free end'portion of the successive lengths of stock tube over the upper longitudinally seamed wall thereof; a heated vertically 'reciprocable end crimping plunger element 46 movably suspended from the frame 25 and being cooperable through the folded bag ends and adjacent upper walls with corrugations 41 in the extreme end of the former plate 32; a resilient lower gripper jaw or plate 48 coacting with the swingable jaw to grip the folded end of the tube preparatory to feeding the stock along the frame 25; a carriage and jaw manipulating handle 49 for reciprocating the carriage 4| and the knife lll and coacting at its upper portion with adjustable stops 59 carried by pivoted elongated side bars 5| in order to predetermine the length of the final bags 52; and mechanism for effecting adjustment of the bars 5| and stops 50 so as to properly position printed or decorative matter on the successive bags 52. I

The main frame 25 may be of any desired rigid construction, andthe former plate 32, rails 42 and bars 5| should be of sufficient length to permit the manufacture of bags 52 of maximum predetermined lengths; and theprinting or decorative matter which is applied to the stock of the roll 2'! before the latter is placed in the bag forming machine should also be properly spaced so that it will ordinarily be located in approximately the desired position on the completed bags 52. The action of the former plate 32 and rollers 33' is well known to those skilled in the art, and when the ribbon 3| is convertedinto tubular formation, the succeeding portion of the'plate 32 is confined within the tube. The structure of the longitudinal seaming mechanism is shown in detail in Figs. 4 and 5, and it is to be noted that the roller 33 may be electrically or otherwise heated, and that the continuous circumferential peripheral grooves 53 of this roller are cooperable with the parallel crimping rods 35 only when the'ribbon 3| is being longitudinally advanced. The ribs or rods35 may be spaced from the former plate 32 as shown in Fig. 5 in order to provide flexibility and compensate for irregularities in stock, but these rods may be replaced by rigid ribs reacting against the plate 32. When the ribbon 3| is at rest, the heated roller 33 should be removed from contact therewith as shown in Fig. 1, in order to avoid scorching or burning the stock, and the roller 33 is therefore automatically elevated by means of the side bars 5| which are swingably attached to the frame 25 by pivots fi l and coact with lateral pro jections 55 on levers 56 which in turn are rigidly attached to pins 51 to which the roller supporting arm 34 is secured. The pins 57 are jour nalled in fixed brackets 58 secured to and forming part of the frame 25, and obviously, whenever the side bars 5| are elevated by swinging the handle 49 forwardly during clamping as in Fig. 1, the seaming roller 33 will be elevated; whereas a rearward pull on the handle 39 as when stock is being fed along the formerplate 32, will cause the roller 33 to gravitate into active or seaming position as in Fig. 2. l V

The lower cutter blade for knife 39 is resiliently supported for horizontal movement relative to the frame 25 by means of several compression springs 59 as shown in Figs. 8'ancl i and this blade has a slightly inclined cutting vancedi towardzande oven thiselower: blade; the lower; blade ispushedi'baok; against the-Pressure exerted; by the springs. 59; and: as; the movable bladeflfl is withdrawnifrom; the. planeof. m vement of; the lower-bladeliia flflQrSpBln S 58 quick- 1y; return. this. latter blade. 39.? preparatory to: the makin iof; a subsequen;t:cut. The movement of theipblade, 4B; in agdownward; direction, besides severing: the tubular ribnonrlili, also; causes the fiexibleyendrof the stringer-plate .8; to deflect slightly: toward the; blade 33;. during downward movement; of jthe blade 4.4; ancli-to-strip the stock therefrom; durin return movement of-z his bl de 'Bhe grippineria w whiclris sciilata le upon a supporting: pivot-1 cylinderqjfifl is. movable; with the carria e M, and: the lower jaw-plate is. adapted t) en age: the, end of the plate=3B7 when the carriage. is advanced Ltov gripping position. When the carriage 4| is thus disposed in gripping Position; the jaw; plate; 485Wi11; haye pushed; the plate 38 beneath; the fixedi reaction plate-31f, and the jaw 45: then; provides; an; anvil orreaction block.- for the corrugated platepor-tion 47 against which: the: pressure: exerted by the crimping plun er. 45: may. be applied;

The upper knife- 40; iswmovableg into activeor cutting posit-ion by; means. of mechanism such asshown in Figs; 8 and. 9; which is actuated by forward; movement: of. the; carriage 4-1;. This mechanism-comprisesarleven lfllbswingably sus nfindedafrom afixedpivot: Hit and "having a latena-lly'projecting' pin IDZadapted to coact with onevarm of. abell-crankrlflS; a spring IM connecting-.theother arm of t-he;bell,crank I03 with the, swinging end of theleverl00-so as to con- 4 stantly; urge the pi l02rtoward the upper bellcrank; arm; an upperbell-crank lever its from one; arm ofwhich themovable knife 40 is suspended, and; which is swingably mounted ona fixed; p inl;l6-; a, connection I971 connecting the othenarm of; the-lever I85: with the lower arm ofrt-he bell-crank-iflb; and a; spring H18 having one end: attachedftda medial portion of. the connection H111 and'itssoppositeend secured. to the stationary frame bracket 58. The lever Hill is adaptedto be engaged by the outwardly projecting end-of tl e carriagei shaft 80 when the carriagefiil is;move d forwardly, so as'to cause the pin.- H121 to. contact the bell-crank 1,03: and to thereby lower the knife 40. into cutting position as'shown-imF-ig. 9,- and when the-pin 80 is carried pastthe tip ofthis lever, lflil, thespring I38 immediately becomes effective to elevate the knife and to-return the.actuatingmechanism to the position: shown in Fig.' 8. During subsequent return? movement ot the carriage 4|; the knife wtwill not be displaced, since the advancing pin 80 will then. ride along the inclined face of the lever: H10 andgwillnswing this lever and the pin I 82: thereonaway fromthebell-crank I63 until the pinall has been carried past the lever tipnwhereupon the spring I04 will again return thedever; H36 and-pin- !32 to theposition shown inl fig; 8.

The crimper 46 is vertically slidable-in grooves formed: in the opposite sidesof the frame 25, and has its ends connected by means of a link 6 l, to the swinging ends of armsBZ-which are pivotally'supported by pins. 63 secured to the frame 25, and springsfiltcoacting with the medial portions of these armsfiZ tend to.urge the same upwardly at all times and thustendto elevate the crimper 46: One or both of the arms-62 may be provided with an; extension. 65 connected by means of a red Gligwithasolenoid 65!, and-this solenoid-is adaptedto-be energized so as tolpositively swingthe arm Stdownwardly-andto lower the-crimper 46', by meansof an electric switch 68. which may be carried by one of the side bars |I andwhich is operable to energize the solenoid when. the handle 49 is swung forwardly to the position shown in Fig. 1.

The vertically reciprocable crimper 46;has its upper; end provided with. a bracket SQ-forming. a. transverse abutment Ill, and the tucker'or. fold:- ing member 44 is carried by an arm I I oscillatable upon a pivot 12 and having an extension 13- which is cooperable with the abutment With this assemblage, downward movement of the crimper 46 will cause the abutment -10 to engage the ex.- tension 13 and will thereby swing: the tucking member 44 out of the path of movement of the crimper 46. In order to prevent the tucker from returning to lowermost position immediately when the crimper is elevated, the pivot 12:is;pro.- vided at one end with a laterally defiectablearm 74 as shown in Figs. 1, 2 and 6; This arm. 14 is adapted to be engaged by a pin licarried by the handle 49, when the tucker or member 441 iselevated by the crimper 46, and when the handle 49 has been moved forwardly to its extreme poshtion so that the pin 15 engages a stop plate T6 secured to the carriage 4|. When the crimper 46 is elevated, the arm 14 engages the pin 15 and the tucker will be held in elevated position as shown in Fig. 2 by the handle 49 which is shown in dash lines in this figure. However, when a pull is exerted on the handle 49, the pin 15 will be withdrawn and the arm 14= is then released and the tucking member 44-is free to drop to its lowermost position.

The gripper jaw or member which performs the dual function of folding the ends of thesuccessive bag assemblages and of subsequently gripping the ends of the'bags so as to permit feeding of the stock, is operableby means of a' bellcrank H secured to the pivot cylinder and having spaced projections 18, 19; The projection l8= is engageable with thelower portion of the handle 49 somewhat above the handle pivot 80,

so as to cause the jaw member 45 to move toward the resilient gripper plate 48. and it is to be noted that as the pull on the handle is increased, the gripping force exerted bythe .jaw member 45 against the jaw plate will also be increased. The projection 190n the bell crank T'lis adapted to engage a cam 8| secured to one of the guide rails 42, so as to elevate the jaw member 45 when the handle 49 and carriage 41 are moved forwardly, and if the handle 49" is in the position shown in Fig. 1 and thishandle is pulled rear; wardly to cause the jaw member 45 .to grip the block 48; then the projection 19 will. beelevated so as not to contact the cam 8|. The handle 49 is also provided at its upper endwith slotted ex.- tensions 82 which are engageable with the bars 5| so as to elevate these bars by causing themto swing. about their pivots 54 as the handle1 49-15 swung forwardly about its lower pivot pin 80, but when the handle is-swungrearwardly theextensions 82 permit the bars 5| to drop slightly and thereby permit the seaming. roller 33 .to en.- gage the tube of stock .during advancement of the ribbon 31. An elongated tension spring 8.4 connects the cylinder BEL with the pin 15. and tends at all times to elevate thegripping member 45.

In order to permit the operator of the machine to. properly position printed, or decorative, mat- ,ter which has been applied to the ribbon 3|, with upper bell-crank I I4 swingably mounted upon the pivot pin 54 and having one arm pivotally attached to one of the side bars 5| while itsjother arm is connected to the other arm of thelower bell-crank III by means of a connecting rod 5.

This assemblage is obviously such, that by shifting the lever I09 in either direction, the position of the tops 56 and sidebars 5|-may be shifted longitudinally. of the machine and without displacing the stops 5!] relative to the bars:

5|, thereby permitting slight: bodily displacement of the successive bags 52 with respectto the cutting knives 39, 40 for the purpose of properly centering or positioningthe printed or decorative matter on the bags.

The normal use of the improved machine while exploiting our present improved method ofmaking bags, is best illustrated in the diagrams of Figs. 17 to 23 inclusive, wherein the various elements which perform the'successive steps of the method are shown somewhat diagrammatically, and in these figures the mechanism is viewed in a direction corresponding to that of Figs. 1 to 9 inclusive. When the machine is in condition for normal use, the supply roll 2'! should bemounted in the bearings 26 and the ribbon 3| should be disposed in contact with the rollers 29, 39 and should be disposed with its medial portion beneath the former plate 32 so as to provide a tubular ribbon with overlapping edge portions,

beneath the folding rollers 3| and the longitudinal crimping roller 33. The stops 50 should be fixed to the side bars 5| at the proper positions so as to produce bags 52 of the desired length, and the roller 33 and crimping member 46 should be properly heated so as to enable these elements to heat the material sufficiently to cause fusion of the coatings" at the crimped areas. The use of the machine to form the several types of bags 52, 52' is essentially the same,

except that a tucker for forming the accordion pleats 93 of the bag 52 should be provided, and the width of the bags will be dependent upon the width of the former plate 32.

Referring to Figs. 17 to 23 inclusive, Fig. 17 shows the cutting and end sealing assemblage just after a bag has been completed and is about to be severed from the ribbon 3|, the upper knife 49 being shown approaching the lower knife 39, and the tucking and gripping elements being remote from the cutting zone with the jaw 45 and plate 49 approaching this zone. With the knife 49 thus approaching the knife 39, the tucking member 44 is located above the corrugated portion 41 of the former plate 32, and the crimper 46 is held in elevated position by the spring 64. The tube has been longitudinally seamed by application of therolle'r' 33 during a previous forward advancement of the ribbon stock, and the jaw member 45 is elevated as shown.

When the upper blade 40 is advanced downwardly as shown in Fig. 18 by continued forward movement of the carriage 4|, it cooperates with the lower blade 39 to shear the previously completed bag52 from the stock ribbon 3|. During thisshearing operation, the inclined: lower edge of the downwardly moving knife 40 contacts with the inclined rear edge of the lower knife 39 at approximately one poini; only and this contact L point advances laterallyacross theplane ofv cut?- ting until the severance has been completed, thus producing .a clean shear cut. Due to the inclina- .tion ofthe rear cutting edge of the'knife'39 this knife is forced forwardly against the springs 59, and the advancementof-the knife 49 also causes the flexible end portion of the stripper plate 38 to ride upwardly along the cutting sideof the knife 49 and thereby positively prevents the end of the tube 3| from sticking to the cutting edge. The tucker 44 and gripping jaw 45 remain in substantially the same relative positions as in Fig. 17 except that the jaw 45 has been advanced toward the plane of cutting with the carriage,

The next step in. the method is shown in Fig.

19 wherein the upper knife 49, hasbe'en elevated away from the lower knife 39, and the gripping .plate 48 and'jaw 45'have been moved into closer proximity to the cut end of the stock tube. The gripping jaw 45 is still elevated but is about: to be swung into contact with the plate 48 by virtue of the engagement of Ithe'roller 19 with the cam 8| during forwardmovement of thecarriage 4|, and the jaw 45 is thereafter lowered as shown in Fig. 20 to cause it to ride beneath the .overhanging endportion 88 of, the tubular ribbon 3|, thus slightly elevating the end .poaion as,

As the roller'l9, passes beyond thetca m" 8|, and the continued forward, movement of thehandle 49 proceeds, the pin 15 engagesthe stop. laten and the handle 49 swings forwardly aboutlits lower pivot 69 to the position shown in das'h lines' inFig.2.

This forward swinging ofthe handle 49; after the movement of the carriage, has been'arrested causes the spring 84to' swing theJbelL crank H and to. elevatethe jaw 45, as indicated in Fig. 21, and the jaw 45-thenbecomes active to fold the. portion 83 over the temporarily fixed tucking member 44 as clearly illustrated in Fig. 21. When the handle 49 has beenswung for.- wardly to the extreme extent, it operates the switch 66 to energize thesolenoid 6l, and this energization causes the-solenoid 61 to swing the arms 62 downwardly against thev actionof the spring 64. The downward swinging of the arms 62.simultaneously"causes the tucking member 44 to be withdrawn from the path of movement of the crimper, and causes thecrimper 46 to lower to the positionshown in Fig. 22. Thecrimper 46 is then free tcperform the crimping and final sealing operation at the end of the tube, and the jaw. 45 is approachingv the plate'48p it is to' be noted that when the 'final crimping-operation is being performed as in'FigQ2'2, the bag is not sharply folded along "the lin'e189, Qand'the plate 45 provides a. reaction anvil for the'lcriinping plunger and corrugated plate portion. 41 f As soon as a crimping operation has .been completed,the operator pulls rearwardly on the hanportion against the plate -48,as illustrated in Fig. 23. As the pull on the handle is continued, the folded end of the tube will be tightly gripped by the jaw45 and the jaw plate 48, and as the carriage 4| is pulled rearwardly, the tubular bag stock is advanced along the former plate 32. During this advancement, the roller 33 is lowered against the overlapped portions of the stock 'by the lowering of the side bars 5|, and the longitudinal seam 81 is thus formed simultaneously with the advancing movement of the stock. when the handle projections 82 engage thelimit stopsfifl, there has been sufficient advancement of the stock to produce a bag of the desired length, and the operation of the carriage may then be reversed to perform a similar cycle of operations. The completed bags 52 which are severed from the continuous ribbon of stock may bedropped upon the floor and loosely stacked upon each other, and maybe Withdrawn as needed, and it will be apparent that the lengths of the bags may be quickly varied by merely adjusting the stops 50.

During the application of the roller '33 and crimper '46, these elements by virtue of their formationproduce the crimping, and the heat applied simultaneously with this crimping produces fusion of the surface coatings at the crimped areas. It will be noted that during the formation of the bottom seal, the folded portion 88 is attachedonly to the rear wall 86 of the bag, and is not attached to the front wall, thereby making maximum storage space for commodity available within the bag. While adhesive may be applied to the crimped areas in addition to the heating, it has been'found that the heating alone will produce bags 52 which are airtight and which can be distended under considerable pressure without bursting and without permitting escape of air from theinterior of the bags. The crimped and fused-seals are preferably formed on one side of the bag, but the folding and crimpingof the lower seal may obviously be applied to the side of the bag opposite to that having the crimped seam 81. The bags 52 maybe produced with straight'cut lower ends and without having one wall project beyond the other, and the improved "adjusting mechanism which is operable by the lever I09, will obviously permit the operator to readily properly position printed or decorative matter on the successive bags. The improved machine and method of producing these bags will also permit a user of small quantities to produce superior bags in a most economical manner and 'asneeded, and such user will always be assured ofa supply of fresh bags wherein sharplyfolded edges are eliminated. The bag forming unit has 'proven highly successful in actual use, and can be readily manipulated by a'novice to produce bags of various types.

ItShOuId be understood that it is not desired to limitthis invention to the precise steps of the method or to the exact details of construction 'herein shown and described, for various modifications within the scope of the claims, may occur to personsskilled in the art.

We claim:

1. In combination, a table, means for folding iopf said walls overone-of thewalls and means for '15-each other and for joining said "edge portions to fusin the folded end areas to said'one wall and to each other.

=2. In-combination, means for folding the edge portions of an advancing sheet of material over form a fiat tube, an oscillatory folding member cooperable'with the endof the tube whileat rest to fold-said end over the upper wall of the tube, means for swinging'said folding member out of ogo the fold, means 'for attaching the foldedareas to the upper tube .waill and toea'ch other toseal said :tube end, aformer plate confined within said sealed tube for preventing attachment :of :said tube walls to each other adjacent to the fold line 5 during said end sealing, and' means-for withdraw- =ing the end sealed tube portion away from said plate.

3. In co'mbinatiommeans for folding the edge portions'of an advancing sheet of material over goeach other and for joining said-edge portions to foi'mxa flat tube, asingle oscillatory bar forming a fold line retaining meanscooperablewith the end of thetube, means cooperating with said fold line retaining means to fold said end over said bar 5 and the upper wall of the tube, means for moving said fold line retaining means out of the fold, means for sealing the folded area to the upper --tube wall to 'sealthe tube end.

4. In combination, in table, means for folding 40 the edge portion (of a sheet of material being advanced alon the said table intooverlapped-position andfor joining said-edge portions to form a flattube, .an oscillatory fold line retaining member cooperable with the end of the tube, means cooperating-With said fold line retaining mem- "ber to fold said end over said fold line retaining 'member and the upper wall of the tube, means for'moving said fold line retaining member out of thefold, meansfor attaching the folded areas .to the'upper-ztube wall and to each other to-seal said'tube end, aformer plate confined within said sealed tube for preventing attachment of said .tube walls to eachzot'her adjacent to the fold line during said end sealing, and gripping means for "gripping and withdrawing the end sealedportion :away from said place.

5. In combination, a table, a former plate, means for folding the edge portionsof a sheet of material/being advanced along said former plate into overlapped position and for joining said end portionto forming flat tube, a fold line retaining bar extending across said former and said tube, reciprocatin mean -for folding the free ends of said-walls over said fold line retaining bar and for withdrawing the end sealed portion away from'sa-id former plate.

' THOMAS E. PIAZZE. ROY-E. HANSON.

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