US2248895A - Bag making machine and method - Google Patents

Description

July 8, 1941. H. w. PARRISH BAG MAKING MACHINE AND METHOD Filed May 29, 1939 5 Sheets-Sheet 1 N VENTO QJ Q/a/e Q/A OI'r/S/Z a; P M I (flTTOmEZyS July 8,1941. H. w. PARRISH BAG MAKING MACHINE AND METHOD Filed May 29, 1939 5 Sheets-Sheet 2 mm RQ N V E. N rob Q/a/e Qmaxr/is/z 15, PM, cm, 61 M. M1

oqTTowsy July 8, 1941. H. w. PARRISH 2,248,895

BAG MAKING MACHINE AND METHOD Filed May 29, 1939 5 Sheets-Sheet 3 mb Q/a/e Q/barrAs/z 19, FHA- M, f'

TTOQEyQ July 8, 1941. H. w. PARRISH BAG MAKING MACHINE AND METHOD Filed May 29, 193.9 5 Sheets-Sheet 4 m J \Q v m a /w W ma, O/a/e War/Ask W i W? A fweu Make fl x N G July 8, 1941. H. w. PARRISH BAG MAKING MACHINE AND METHOD Filed May 29, 1939 5 Sheets-Sheet 5 7 IIII/fl'II/IIIII I I i "n C r H will/4 I O/a/e Q/DOI'IVS/Z Patented July 8, 1941 BAG MAKING MACHINE AND DETHOD Hale W. Parrish, South Bend, Ind., asslgno rto Kiean Holder Corporation, Detroit, Mich, a

corporation 01' Michigan Application May 29, 1939, Serial No. 276,324

20 Claims.

The invention relates to a method and machine for bag making, and more particularly for making bags with interiorly located lifting strips.

Bags of this character are especially handy as sanitary containers for foods as, for example, sandwiches. For this purpose, the bag may be made oi any suitable material such as plain paper, wax paper, Cellophane, or the like. The lifting strip may also be made of paper and in the form of a strip doubled upon itself. One end of the strip is attached to the bag near its mouth and extends down into the bag with the fold of the strip at the bag bottom and the free end oi. the strip projecting from the bag mouth. When so located, the strip embraces the bag contents, and by pulling on the free end of the strip the contents may be gradually moved out of the mouth of the bag.

The general object of the present invention is to provide a novel method and machine by which bags with interiorly located lifting strips may be made at high speed and at very low cost.

A more specific object of the invention is to provide a method and machine for making bags of the type described, characterized by the initial attachment of the folded lifting strips to an advancing sheet of bag material and subsequent folding of the sheet about the strips in bag body form so that a lifting strip is located on the inside of each bag when the latter are completed.

A further object is to form the lifting strips from a roll of ribbon advanced in synchronism with the sheet from which the bags are formed.

Another object is to provide a method and apparatus for making bags of the type indicated. of such character that the bags may be formed by transversely severing a tubular piece of bag material at successive points without also severing lifting strips located within the tube and extending across the line of transverse severance. In this way an end of the strip is left projecting from the mouth of the completed bag in position to be readily gripped by a user.

The invention also resides in various structural improvements in the machine by means of which the bag-forming, strip-forming and stripattaching operations are all accurately correlated and synchronized.

Further objects and advantages of the invention will become apparent as the following description proceeds, taken in connection with the accompanying drawings, in which Figure 1 is a perspective view of a finished bag with attached lilting strip, made in accordance with the method and by the machine herein disclosed.

Fig. 2 is a vertical sectional view along the line 22 in Fig. 1.

Fig. 3 is a genemlly schematlc perspective view showing the progress of the materials as they are formed into lifting strip bags like that of Fig. 1.

Fig. 4 is a detail perspective view of a forming plate utilized in the bag forming machine.

Fig. 5 is an enlarged transverse sectional view along the line 5l of Fig. 3.

Fig. 6 is a schematic side elevation 01' a bag making machine embodying the invention.

Fig. 'i is a diagrammatic layout or the gearing included in the drive mechanism for the machine of Fig. 6.

Fig. 8 is a side elevation, partly in vertical section, of the portion of the machine at station A in Fig. 6.

Fig. 8 is a detail stop-motion view of a portion of the mechanism of Fig. 8.

Fig. 9 is an end elevation partly in section along the line 0-9 in Fig. 8' of a portion of the mechanism of Fig. 8.

Fig. 10 is a detail perspective view of one of the driving gears showing its micrometer adjustment mounting.

Fig. 11 is a side elevation of the apparatus included at stations E and F in the machine of Fig. 6.

Fig. 11 is a stop-motion view of the apparatus at station F shown in Fig. 11.

Fig. 12 is a side elevation of the apparatus included in the machine of Fig. 6 between stations F and G.

Fig. 13 is a detail perspective view of part of the apparatus included at station F, as shown in Fig. 11.

Fig. 14 is a side elevation, partly in vertical section, of the apparatus included in the machine of Fig. 6 at station B.

Figs. 15 and 16 are respectively plan and side elevations of the apparatus at station C in the machine of Fig. 6.

Fig. 17 is a fragmentary perspective view or a modified forming plate adapted to replace that 01 Fig. 4 in the machine of Fig. 6.

The invention is exemplified herein as applied to the making 01' bags ll each having a folded and interlorly located lifting strip II. This particular bag is or flat form with a plain, unseamed front wall I! and a back wall formed by overlapping portions ll-|I adhesively secured together to form a longitudinal seam. The bottom o1 the bag is closed by doubling the bag upon itself at I! and securing the folded end in place by adhesive. The open upper end or mouth III of the bag may be closed by a flap l9, which constitutes an extension on the rear wall. The lifting strip II is secured near the open end of the bag to the inner side of the front wall |2 by adhesive 2|I, and the free end ll of the strip projects beyond the short front wall but short of the end I! of the rear wall, being readily accessible at the open end of the bag.

It will be understood that the present invention is applicable to the manufacture of a large variety of other forms of lifting strip bags. Consequently, even though a particular application of the invention has been shown and described in some detail, there is no intention to thereby limit the invention to such application. but, on the other hand, the appended claims are intended to cover all alternative applications, methods and constructions falling within the spirit and scope of the invention.

Briefly stated, the method herein contemplated includes the steps of advancing a continuous sheet of paper or other bag material in an endwise direction, attaching afolded lifting strip to the advancing sheet, folding the sheet about the strip to form a bag body, and then severing the folded sheet to complete the bag. By first locating the strip on the sheet and then folding it about the strip, the latter is properly located in the interior of the completed bag. Furthermore, this method is particularly well adapted to be carried out by an automatic machine operating at very high speed since successive strips may be formed from a continuously advancing ribbon and attached to the bag sheet while the latter is in motion and without interference with any of the bag-forming steps.

In the illustrative application of the method herein disclosed (see Fig. 3), the bags iii are formed from a sheet of paper 2| unreeled continuously from a supply roll 22. In general, the manipulation of the sheet 2| is that commonly used in making flat paper bags and, consequently, a detailed description of the machinery for accomplishing it is believed to be unnecessary. In brief, the advancing sheet 2| first passes through station A where adhesive is applied along its side edge 2| for subsequent completion of the longitudinal bag seam. Then, the sheet passes beheath an angular forming plate 23 (see also Fig. 4) at station B. The side edge portions II and ii are progressively folded in over the forming plate 23 and their overlapping edges are pressed together so that the sheet is glued in tubular configuration. Next the tube is severed transversely at station G into successive sections III. Finally, the bottoms H of these sections are folded at station D to complete the bags Ill, the finished bags being carried away by the conveyor belts 2|, 25.

In addition to the usual bag forming steps outlined above, two other or new operations are performed on the advancing sheet 2|, preferably at station A, to condition it for receiving the lifting strips These are respectively the cutting of the sheet to form transversely extending slits 26 at points spaced longitudinally of the strips to correspond to the upper ends of the rear walls of successive bags and the application of dabs of glue or other adhesive at points slightly in advance of each of the slits 28. These spots of glue secure the short ends ll of the subsequently applied lifting strips H on the sheet. The slits 26 serve to prevent tearing of the projecting tab ends H of the strips when the bag sections are severed at station C, as will hereinafter appear more fully.

The lifting strips II are also formed from a continuous length of material, in this case a ribbon of paper 21 (Fig. 3) unrolled from a supply spool 28. As this ribbon advances, it is cut into separate lengths 21' at station E, which sections are doubled or folded upon themselves at station F to form the finished lifting strips H which advance with their short ends li facing the sheet 2|. The paths of the advancing bag material 2| and strips merge at station G where the strips are fed onto the sheet at a rate exactly matched with the latters rate of advance. The shorter portion of each successive strip II is pressed against a corresponding spot 20 of adhesive and located with the free end of the longer strip leg projecting across the center slit 28. After the lifting strips II have been glued to the sheet 2| in this manner at station G, the formation of the bags l|l is continued as described above, the sheet 2| being folded about the strips II in the form of a bag body with the strips located inside the same.

The severing of the separate bag sections ill (Fig. 3) from the tubularly folded material 2| is preferably accomplished by a tearing operation. The lower side of the tube (as viewed in Fig. 3) can, for example, be torn transversely by pulling it sharply up against the trailing end edge of the forming plate 23. The difllculty is, however, that this tearing must be accomplished without also tearing of! the end ll of the lifting strip which projects beyond the mouth of the bag. It is to meet this diiiiculty that the preliminary center cuts 26 are made in the sheet. With the sheet 2| so cut the severance of the tube bottom wall can be completed by tearing this wall along transverse lines merging with the ends of the slits 26 while not applying any substantial tearing force at the center of the sheet where the lifting strips II are located. For this purpose the lower end of the forming plate 23 is fashioned with a smoothly rounded center portion 29 (Fig. 4) matching in length the center slits 26. At each side of the portion 29 cutting edges are fashioned in the form of sharp teeth lll. With the end of the forming plate so shaped the bottom of the tubular material folded about it can be pulled upward, as, for example, in the usual manner of tearing a piece of paper along a straight edge, and it will be turn in two spaced lines merging with the ends of the center slits 28. The projecting ends H" of the lifting strips ride up over the rounded center section 29 during this operation without being torn or harmed. It will be apparent, however, that in order for the operation to be carried out successfully, the center slits 26 must be located accurately in registry with the end of the forming plate 23 when the tearing operation is carried out. The machine herein disclosed is particularly adapted to accomplish the nicety of timing required for this purpose.

An important advantage of the method described above is its adaptability to high speed production. The improved machine herein disclosed may be advantageously utilized in carrying out this method. In many respects, this machine resembles those heretofore used in making flat paper bags without lifting strips. Accordingly, the succeeding description and drawings are directed particularly to those parts of the machine which are new in character and especially adapted to the manufacture of bags with interiorly located lifting strips.

For an understanding or the general layout of the illustrative machine embodying the invention and adapted to carry out the method described above, reference should be had to the diagrammatic view in Fig. 6. In this machine, the paper sheet 2| is led from the roll 22 over freely revoluble guide rollers 3|, 32, then through station A, and thence between a pair of opposed power-driven friction guide rollers II, it at station G which bear lightly on the paper sheet 2|. At station A, the sheet 2| passes over a power driven roller 35, which cooperates with an opposed roller 35 to form the center slits 2i and apply the spots of adhesive 20 (see Fig. 3) in a manner hereinafter described. Also, at this station a roller 55, running in a bath of liquid adhesive 51, applies adhesive along the side edge 2| of the sheet (see Fig. 3). After leaving the guide rollers 33-, the sheet 2| is drawn along the former plate 23 by a pair of power driven draw rolls 31 and 38 which are adJusted to provide suilicient friction for pulling the sheet 2| through the machine. The draw rolls l1 and I5 establish the feed rate of the paper sheet 2| and the other rolls are adjusted to rotate in synchronism therewith. As a result of the tension exerted on the paper sheet 2| by the rolls I1 and 38, the side edges of the sheet are folded in about the former plate, being pressed down and pulled together by draw-in rollers 58 (see also Fig. 15). At station 0, the sheet, then in tubular form, is severed into its successive sections ID by a striker bar 40 which is revolved in a vertical plane transverse to the path of movement of the bag material. Thereafter, the sections it are fed by a pair of feed rollers "-52 into the usual mechanism at station D for folding the bottoms ll of the bags and including a pair of opposing rollers 53-. Finally, the finished bags are advanced by feed rollers 45-48 onto the top of the conveyor belt 25.

Turning now to the mechanism for forming and applying the lifting strips II, it will be noted that the unreeling of the paper 21 from the spool 28 is accomplished by a pair of opposed power actuated feed rollers 41- Fig. 6). These feed the ribbon 21 at a speed substantially twice that of the sheet 2| since a piece of ribbon substantially twice the length of a bag section must be provided to form the lifting strip for each bag. After leaving the feed rollers "-48, the paper ribbon 21 passes through a severing mechanism at station E embodying a pair of opposed rollers "-50, one of which carries a severing blade 95, thence through a second set of feed rollers 5|52 to a strip folding mechanism at station I". This folding mechanism also embodies a pair of opposed rollers 53-54 carrying suitable tucking or folding devices hereinafter described. Upon leaving the folding mechanism at station F, the lifting strips II are still advancing at a speed substantially twice that of the sheet 2|. Their speeds must, however, be synchronized when their paths merge at station G where the strips are attached to the sheet of bag material. Accordingly the rate of advance of the lifting strips ii is slowed down between stations F and G by passing them through successive sets of slow-down" rollers 55-58 and 51-55, which are driven at successively slower speeds. The lifting strips H, as well as the sheet 2|, are passed between the feed rolls 33- at station G and at this point the lifting strips are pressed against the spots ll of adhesive on the sheet of bag material 2|. Then, to hold the freshly applied lifting strips in position they are pressed against the sheet 2| by a flezdble belt 5|, made of canvas or the like, which is led over pulleys 5|, Ii, and 52.

To insure proper relative timing of the various parts of the machine, all are preferably driven through suitable gear trains from a single source of power such as an electric motor (not shown). In Fig. 7 the layout of the gearing has been shown diagrammatically. In this figure the circles indicate the pitch circles of the gears, those on the front of the machine being shown in full lines and those on the back in dotted lines. Of course, in some instances, a gear on the front of the machine covers a gear of the same diameter on the back of the machine. To facilitate an understanding of the relation of the gearing of Fig. 7 to the associated rollers, etc. in Fig. 6, the gears of Fig. 7 which are fast on rollers of Fig. 6 have been given the same reference numeral with the designating letter (3" added. For example, the gears on the main feed rollers 33, ll (in Fig. 6) are designated in Fig. '7 as "G and G.

Power is supplied to a drive pulley 53 (Fig. '1) which is connected through bevel gears 54 with two alined drive shafts 55 and 56. These shafts respectively drive the parts of the machine on the right and left hand sides of station B. Thus, the first drive shaft 65 is connected through bevel gears 51 and intermediate gears 58 with the guide roller gear 33G, which is in turn connected to a gear in mesh with the second guide roller gear G. The feed roller gears 510 and 58G are driven at a somewhat higher speed than the feed roller gears G, "G from a gear 59 (fast with the gear 350) through an intermediate gear ll. Also driven by the bevel gears 81 on the drive shaft is an intermediate gear H which, through intermediate gears 12, drives the tucking roller gears "G and SIG. Passing on down the machine, feed roller gears 5|G, 52G are driven through an idler it while a second idler ll meshes with one of the severing roller gears G which in turn meshes with its complemental roller gear "G. The feed roller gears 41G, G are driven through an idler 15 from an intermediate gear ll fast on the roller gear G. This latter gear also meshes with an intermediate gear ll fast on the roller gear 35G which in turn drives the complemental roller gear 356.

At the left hand end of the machine (as viewed in Fig. 7) the second drive shaft 65 carries the rotating striker bar I. Additionally, this shaft drives the feed roller gears MG and "G through a set of bevel gears 18. The gear G in turn meshes with an intermediate gear 19 fast on a second intermediate gear 50 which drives the draw roll gears "G and 350. A sprocket 8| fast on the gear "0 drives a second sprocket 82 through a chain 83, and this second sprocket is connected through gears II with the belt pulley 60. The bag-end folding rollers 43- and feed rollers 45-55 are of conventional construction and their drive gears have not been shown. They may, however, be driven from the shaft 55 by suitable connecting gearing.

Bearing in mind the general layout of the machine as described above, attention may now be given to a more detailed consideration of the particular mechanisms included at the diflerent stations in the machine. The apparatus at station A (Fig. 8) includes, as was previously noted,

a pair of cooperating rollers 85 and 88. To apply adhesive along the edge 2i of the sheet of bag material 2i (see Fig. 3) the usual glue applying roller 85 (Fig. 8) is utilized. This roller is ioumaled in the top of a pct 88 containing liquid adhesive 81 and is of an axial width equal to the width of the line of adhesive to be applied to the sheet 2I. The roller 85 is revolved by frictional contact of the sheet 2| against it as the latter passes over the opposed roller 85.

A second glue roller 88, fast on the roller 88. but of smaller diameter to provide clearance for a knife 88 by which the slits 28 are formed, supplies adhesive from the pot 88 to an applicator finger 88 on the upper roller 88 and this finger in turn applies the dabs 28 of adhesive to the advancing sheet 2i at accurately spaced points. The knife 83 projects from the roller 88 beyond the point of glue application making it necessary to move the applicator finger 88 to contact the glue roller 88. For this purpose, the applicator finger 88 is pivoted on the roller 36 by pin 88 and a stop pin 8| on the applicator finger is urged by a spring 82 into engagement with a fixed cam 82 secured to the stationary bearing sleeve 88 (Fig. 9). The pin 8| contacts and follows the profile of the cam 82 so that the finger is projected outwardly and contacts the roller 88 thereby picking up adhesive. As the pin 9| passes the cam, it is moved by the spring 82 to the position shown in Fig. 8 in which the finger is located for proper transfer of the adhesive to the traveling paper web 2|. In this way the finger applies a spot of adhesive on the sheet once during each revolution of the roller 35. This latter roller also carries the knife or blade 85 located centrally of the sheet 2| and registerable with a slot 84 in the opposed roller 35. The blade 83 thus forms the center slits 28 in the advancing sheet at precisely spaced points. The length of the center slits 28 approximates the width of the strips II. Minimization of the slit length is desirable since in that way maximum longitudinal tensile strength of the sheet is retained to resist rupture while being pulled through the machine.

At station E (Fig. 11) the advancing ribbon of paper 21 is severed into successive sections 21 by the knife or blade 95 projecting from the periphery of the roller 58. A cooperating recess 85' in the opposed roller 49 receives the end of the blade as it passes through the strip. The feed rollers I-52 are located sufficiently close to the rollers 48-58 to grip each of the sections 21 before it is severed from the continuous ribbon 21 and direct it between the tucking rollers 53-54 at station F.

At station F (Fig. 11) each successive strip section 21 is folded or doubled upon itself to form a completed lifting strip II. For this purpose a dull edged tucking blade or plate 85 extending longitudinally of the roller 54 is arranged to engage each successive strip section and tuck its mid-portion into a complemental recess 81 in the cooperating lower roller 53. The parts are so timed that each strip section is passed between the rollers 53-54 for a little more than half its length (more than half, so that the upper leg of the folded strip will be longer than the lower leg in the finished strip) before the tucking blade 98 contacts it and tucks it into the groove 81. The projecting end of the strip 21 which has passed on between the rollers 53-54 is received temporarily on a guide plate 88. The tucking blade 85 is pivoted on a. pin 88 in a V-shaped longitudinal groove I88 in the upper roller 54 and is spring-pressed toward the forward face of this groove so that it yieldably urges the paper strip into the tucking recess 81 in the lower roller 58.

To hold the portion of the strip 21' that has been pressed into the tucking groove or recess 81. a pivoted gripper plate I" is utilized. This plate extends longitudinally of the recess 81 and carries an arm I82 and a roller I88 (Figs. 11 and 13). The pivoted arm III is spring-pressed against a peripheral stationary cam I84 (Fig. 11). and this cam is contoured to hold the arm I82 raised. so that the gripper plate III is correspondingly lifted from the trailing face of the tucking recess 81, until the strip 21' has been thrust into the recess 81 by the tucking plate 88. Thereafter, the recess in the top of the cam I84 permits the arm I82 to drop down so that the gripper plate IIII presses the folded center portion of the paper strip 21 against the trailing face of the tucking recess 81. Consequently. continued rotation of the roller 58 draws the strip section on about the periphery of the roller to continue the folding action along the length of the strip (Fig. 11").

To release the folded strips from the lower tucking roller 58. the cam I84 is contoured to shift the gripper plate I8I to released position after the roller 58 reaches approximately the position shown in Fig. 11a. Thereupon, the resiliency of the paper tends to cause it to snap out of the tucking recess 81 so that it is received upon a downwardly inclined guide plate I81. To positively insure stripping of the folded paper from the roller 58 a plurality of fingers I88 (Fig. 13) are fashioned on the forward edge of the guide plate I81. These fingers project into peripheral grooves I88 on the roller 58 and thus force the folded nose of each strip of paper out of the tucking groove 81. To prevent slippage or stopping of the strip 21 after release by the gripper plate IN a roller I85 is arranged to press the paper strip against the periphery of the roller 58 (Figs. 11, 11" and 13). This roller I85 is journaled on a pivoted arm I88 and is driven frictionaliy by the continuous end portions 58 of the roller 58 which it contacts.

Upon being freed from the lower tucking roller 58 the folded strips II are directed to station (3 along a seriw of inclined guide plates 8 (Fig. 12). The slow-down" sets of feed rollers 55-58 and 51-58 are arranged at intervals along this path so as to slow up the rate of advance of the folder strips II. As was previously noted, the paper ribbon 21 from which the lifting strips are formed must initially be fed at a rate substantially twice that of the bag material sheet 2I but after the strips are formed they must be slowed down so that their rate of advance matches that of the sheet of has material. In the present machine this is done by feeding the strips through the successive pairs of slow-down rollers which are operated at successively slower speeds. It is desirable to use a plurality of such sets of slow-down rollers so as to minimize the resultant buckling of ithe advancing strips between each successive pa r.

0n reaching the guide rollers 88-84 at station G (Fig. 2) the strips II are pressed by these rollers against the face of the advancing sheet 2i. At this point, the rates of sheet and strip advance are exactly synchronized since both the strips and the sheet pass through this same set of rollers. By timing the slow-up rollers (through the medium of their gear drives heretofore aasaaos described) the delivery of the strips ll onto the sheet 2! is so timed that each strip will be accurately located on the sheet with its short underside leg overlying a spot of adhesive 20 and its longer upper leg overlying a center slit It in the sheet 2| (see. also Fig. 3). In passin through the guide rollers 83-. the strips Ii are pressed against the sheet 2| so as to cause the strips to be firmly glued in place. Incidentally, it should be noted that the'side edge portion Il' (see Fig. 8) of the sheet 2| to which glue has been previously applied for the bag seam is located beyond the end of the upper roller 34 so that this glue will not smear the roller.

By forming the strips II in timed relation with the advance of the sheet ii, the manipulation of these strips is greatly simplified. when utilizing this arrangement it is unnecessary to provide any intermediate storage space for the strips prior to their delivery to the sheet and also any problem of ting or picking these strips out of a stored batch of them is obviated.

After the strips II have been attached to the sheet II, the latter is progressively folded into tubular or bag body form by drawing it along and about the former plate ll (Figs. 8 and 4). In starting a sheet of paper Ii through the machine, its forward end portion is folded about the former plate It and thrust between the draw rolls "-3! (Fig. 16). These latter rolls register with an aperture ill in the former plate and grip the sheet at this point. Thereafter, upon starting the machine the draw rolls pull the sheet along and it is progressively folded about the former plate in the usual manner. The former plate II (Fig. 4) embodies a long rectangular horizontal body portion and an upwardly inclined portion at its leading end. Former plates of this general character are well known in the art and. accordingly, further description of its operation is believed to be unnecessary. Aside from the special tearing end construction heretofore described the former plate herein shown differs from the usual construction only in that a longitudinal slot H2 (Fig. 4) is fashioned in it. This center slot forms an open way for the lifting strips ll glued on the sheet ll so that the former plate does not tend to dislodge them. To further aid in holding the strips II in position the belt It (Figs. 12 and 14) is arranged to press the strips against the sheet 2| while the sheet is passing along the inclined forward portion of the former plate and any tendency of the strips to slide down this incline is thus checked.

By attaching the lifting strips II to the center portion of the sheet 2| any impediment to proper folding of the sheet about the former plate 23 is avoided. In other words, the strips are attached to a part of the sheet, namely, the center portion, which is not longitudinally folded during the formation of the bag, but is, on the other hand, retained substantially flat throughout such forming operation. As a consequence the strips do not interfere with the longitudinal folding of the sheet into tubular form.

The usual draw-in rollers I9 (Figs. 14 and 15) are pivotally mounted above the horizontal porinto proper overlapping relation. Also in the usual manner a finger ill (Fig. 16) leased to push down the side edge portion ll of the sheet so that it is held out of contact with the other edge portion ll until the two are pulled into proper overlapping relation for gluing them together. While passing between the draw rolls "-4! the overlapping portions "-4! of the sheet are pressed tightly together to complete the longitudinal bag seam.

At station C (Figs. 15 and 16) the tubularly formed sheet 2! is severed into successive sections ill by the striker bar I. As previously noted, the end of the former plate 23 is fashioned to constitute a tearing edge or cutter to cooperate with the striker bar for severing the bottom wall of the' tube. The upswingins st ker bar lll (Fig. 16) pulls the lower side of the tube up across the end of the former plate 23. Consequently, the sharp teeth 30 (Fig. 4) tear this bottom tube wall along lines merging with the center slit 26, which at this instant registers with the end of the former plate. The projecting strip H is pulled up across the rounded center part 29 of the former plate 23, however, so that it is not torn oil or damaged.

A suitable alternative former plate end is shown in Fig.17. The same reference numerals have been used for identical parts. It diil'ers from that of Fig. 4 only in that it is recessed at 2,9 to protect the projecting strip end rather than having a rounded edge in its center portion.

The striker bar I also serves to tear off the top wall of the bag material tube. Cooperating with it for this purpose is a stationary cutter H6 (Figs. 15 and i6) presenting a concave series of cutting teeth Ill. This cutting edge or series of teeth is concave so that the top wall will be torn off along a correspondingly curved line to form the flap I! at the mouth of the completed bag (Fig. 1). Furthermore this concave series of teeth is offset from the end of the strips ll so that this upper row of teeth has no tendency to tear the projecting strip ends.

After leaving station C the severed bag sections ill have their lower ends folded and glued at station D (Fig. 6) and are carried away by the conveyor belts 21-25, all in the usual manner. This apparatus following station C may all be of conventional form and, accordingly, further description is believed to be unnecessary.

From the foregoing description of the construction and operation of the machine it will be apparent that great nicety of timing is required between many of the parts. This problem is especially acute in view of the extreme speeds of material feeds encountered in turning out bags at a rate of 350 per minute as the machine above described is capable of doing. With such high speeds. even a small error in timing will be so greatly multiplied in the course of a few minutes of operation as to spoil the product. The positive maintenance of a timing relation once established is insured by actuating all of the parts through positive gear drives from a single or common source of power. To obtain the required precise timing and enable the machine to be adlasted for the making of bags of difierent lengths and widths, provision is made for:

(a) Adjustment of the fold forming mechanism so that the position of the fold in the lifting strip may be varied relative to the advancing end of the strip;

(b) Adjustment of the knife 93 and the glue applicator finger 88 with respect to the movement of the lifting strip so that the folded strips will be applied at the proper points to the advancing paper sheet: and

(c) Adjustment of the slit forming knife in relation to the striker bar 40 for cutting off the successive bags.

Adjustment of the fold forming mechanism is effected by advancing or retarding the gears of the trains which extend from a common point at the bevel gears II successively to stations F, E, and A. For this purpose, one of the gears can be advanced one tooth or more with respect to the next meshins fiear until the one of the driven rollers selected for adjustment has been turned to the angular position necessary for proper timing of the operationwhich it perform. Next, the timing of the knife 03 and the applicator 89 is changed by advancing or retarding the gear 11 so that each strip ii will be delivered at exactly the right instant for location properly with reference to the slit 2i and the glue spot 20. Finally, the angular position of the knife 83 (Fig. 7) can be changed by advancing or retarding the scars II and I! so that each slit it will be disposed directiv opposite the striker bar at the time the latter acts to cut on a bag. As an incident to adjustment of the gears II and I2, it-wiii be noted that the previously adjusted relationship between the knife I! and the folding mechanism will not be disturbed.

In some instances the advance of a full tooth on one of the gears may be too coarse an adjustment. To take care of such a contingency. various gears in the train are adjustably secured to the shafts which carry them. For example, at station A the gear ll (Fig. 10 and see also Fig. 7) which is carried on shaft 36 of the roller It. is secured to this shaft by a split sleeve clamp 11. Upon loosening this clamp the shaft 36' can be turned relative to the gear 'Il so as to adjust its position with precision and through as small an angle as may be desired. Thereafter, the clamp is, of course, retightened. It will be noted that during this adjustment the rollers ,35 and 88 remain connected to each other through the gears "G and 866 (Fig. 9) at the opposite end of the shaft 36" from the gear l1. Accordingly, an anular adjustment of the roller It will effect a cor p nding turning of the opposed roller 35 so that the knife 93 always remains in proper angular position for registry with the slot 9| in the roller 35. In the other pairs of rollers carrying cooperating parts the adjustment of these parts may be similarly maintained.

From the foregoing it will be seen that the relative timing of all of the cooperating machine parts can be adjusted with extreme precision. Having once been adjusted, the machine can be set in operation and bags are turned out entirely automatically with the lifting strips attached and accurately located inside them, all at a very high rate of speed.

I claim as my invention:

1. The method of forming a bag with a folded lifting strip therein, which comprises, advancing a continuous sheet of bag material in an endwise direction. attaching one end of a folded strip to the longitudinal center portion of said sheet during the advance of the latter and with the strip extending longitudinally of the sheet, folding the side edge portions of said sheet inwardly into overlapping relation with each other and about said strip to form a bag body enclos ing said strip, and cutting off the folded sheet to complete the bag.

' p ises,

2. The method of forming a bag with a folded lifting strip therein, which comprises. advancing a continuous sheet of paper or the like in an endwise direction, attaching one end of a folded strip to said sheet during the advance of the latter, folding said sheet about said strip to form a bag body, and cutting oi! the folded sheet to complete the bag.

8. The method of forming a bag witha folded lifting strip therein, which comprises, doubling a strip upon itself to form a lifting strip. gluing one end of the strip to a face of a sheet of bag material, and folding the sheet into the form of a bag body with said sheet face constituting an inner wall of the bag.

4. The method of forming bags with a folded lifting strip in each, which comprises, advancing an elongated sheet of paper or the like endwise, attaching folded strips to said sheet at successive points along its longitudinal center portion, then progressievly folding the side edge portions of the sheet inwardly into overlapping relation with each other and overlying said strips to bring the sheet into generally tubular bag body configuration with the strips enclosed in the tube while retaining the central portion oi? the sheet and to which the strips are attached substantially flat, and severing the tubularized sheet at successive points intermediate the points of strip attachment.

5. The method of forming bags with interiorly located folded-lifting strips which includes the steps of advancing a continuous sheet of paper and a narrower ribbon endwise along adjacent paths at continuous rates and severing and folding strips from said ribbon at a rate synchronized with the rate of sheet advance, attaching the folded strips to said sheet at spaced points thereaiong, and folding said sheet about the successive strips to form bag bodies.

6. The method of forming bags with interioriy located folded lifting strips, which includes the steps of advancing a continuous sheet of paper or the like endwise at a continuous rate, severing and folding strips from a continuously advancing ribbon at a rate synchronized with the rate of sheet advance. attaching successive strips to the advancing sheerI at equally spaced points along the sheet, folding the sheet about the strips, and cutting the folded sheet into successive bag lengthsm at points disposed between the successive s ps.

7. The method of forming bags with an interiorly located folded lifting strip in each, which advancing endwise a continuous sheet of paper or the like, slitting the sheet transversely at spaced points along its center line and intermediate its side edges, attaching folded strips to the center portion of the sheet at spaced points with a free end of each strip overlying a corresponding slit, progressively folding the sheet about the strips in a bag body form, and cutting on successive portions of the sheet along zfiiznsverse lines merging with the ends of the 8. The method of forming a bag with an interiorly located folded lifting strip having one end protruding from the bag mouth, which comprises. advancing endwise a continuous sheet of bag material, partially severing the sheet in a transverse direction at successive points during its advance. then attaching folded lifting strips to the sheet at spaced points with a portion of each strip overlying a corresponding slit in the sheet, folding the sheet about the strips in bag body form, and completing the transverse severance of the sheet at the point where it was previously partially severed.

9. The method of forming bags each having long andshort walls and an interiorly disposed folded lifting strip with long and short legs respectively disposed adjacent said long and short walls, said method comprising advancing a sheet of bag material endwise at a uniform speed, ad-

vancing'a narrower ribbon endwise and alongside said sheet at a substantially greater speed,

. cutting successive lengths from said ribbon, foldoff the folded sheet to complete the bag with the strip disposed therein. l

14. A bag forming machine comprising, in combination, means for advancing in an endwise direction a continuous sheet of bag material, means for advancing a strip of material alongside said sheet and forming the same into separated folded strips, means for attaching one end of each folded strip to the longitudinal center portion of the sheet while the latter is being advanced by said first named means and with the strip extending longitudinally of the sheet, a former plate embodying an elongated flat body portion and an upwardly inclined leading end portion, means for drawing the sheet with the strip., attached along the bottom of said former plate and for folding the side edge portions of ,the sheet progressively inward about said former 10. The method of forming bags having interiorly disposed folded lifting strips comprising advancing a paper sheet endwise, advancing a narrower ribbon endwise at a substantially greater speed than said sheet, cutting successive lengths from said ribbon, folding each length to form a folded strip, decreasing the speed of advance of the folded strip to bring the same into synchronism with saldsheet, attaching the adjacent leg of the strip to said sheet, folding the sheet longitudinally about the strip to form a bag body, and cutting the folded body into bag lengths each having a folded strip disposed there-- 11. The method of forming bags having interiorly disposed folded lifting strips which includes the steps of advancing a sheet of bag material endwise, advancing a narrower ribbon endwise at a substantially greater speed along a path substantially merging with the path of said sheet, cutting successive lengths from said ribbon, folding each length to form a folded strip, and decreasing the speed of advance of the folded strip to bring the same into substantial synchronism adjacent the points of mergence of said paths.

12. A bag forming machine comprising, in combination, means for advancing in an endwise direction a continuous sheet of paper or the like, means for advancing a strip of material alongside said sheet and forming the same into separated folded strips, means for attaching one end of each folded strip to the sheet during its advance by said first named means, means for folding the sheet about the strip in the form of a bag body, and means for cutting off the folded portion of the sheet to complete the bag.

13. A bag forming machine comprising, in combination, means for advancing in an endwise direction a continuous sheet of bag material, means for advancing a strip of material alongside said sheet and forming the same into separated folded strips, means for attaching one end of each folded strip to the longitudinal center portion of the sheet while the latter is being advanced by said first named means and with the strip extending longitudinally of the sheet, means for folding the side edge portions of the sheet inwardly into overlapping relation with each other and about the strip to form a bag body enclosing the strip, and means for cutting plate into overlapping relation while retaining the center portion of the sheet flat against the bottom of said former plate, and means for cutting off the folded sheet as it leaves said former plate to complete the bag.

15. In a. machine of the type described, the combination of means for advancing in an endwise direction an elongated sheet of paper or the like, means for advancing a strip of material alongside said sheet and forming the same into separated folded strips, means for attaching the folded strips to said sheet at successive points along its longitudinal center portion, means for progressively folding the side edge portions of the sheet inwardly into overlapping relation with each other and overlying the strips to bring the sheet into generally tubular bag body configuration with the strips enclosed in the tube, said last named means being operative to retain the central portion of the sheet substantially flat during said folding operation, and means for severing the tubular sheet at successive points intermediate the points of strip attachment.

16. In a machine of the type described, the combination of means for advancing in an endwise direction a continuous sheet of paper or the like, means for slitting the sheet transversely at spaced points along its center line and intermediate its side edges during the advancing movement thereof, means for advancing a strip of material alongside said sheet and forming the same into separated folded strips, means for attaching the folded strips to the center portion of the sheet at spaced points with a free end of each strip overlying a corresponding slit, means for progressively folding the sheet about the strips in a bag body form, and means for cutting off successive portions of the sheet along transverse lines merging with the ends of the slits.

17. In a machine of the type described, the combination of means for advancing in an endwise direction a continuous sheet of bag material, means for partially severing the sheet in a transverse direction at successive points during its advance, means for attaching folded lifting strips to the sheet at spaced points with a portion of each strip overlying a corresponding slit in the sheet, means for progressively folding the sheet about the strips in bag body form, and means operable in timed relation with said first named severing means for completing the transverse severance of the sheet at the points where it was previously partially severed.

18. In a machine of the type described, the combination of means for feeding a continuous sheet of paper or the like in an endwlse direction and at a substantially continuous rate, means iorseveringandioldingsuccmsivestripsirem a continuous ribbonotmaterlsLmeansior attaehingthesuccessivcioldedstrlpstotheadvancing sheet. and mean for correlating the ratesoioperationofsaidflrstandseoondnamed means.

lamamachineotthetypedescrlhedthe combinationoi'meamiordirectingacontinuous sheet of paper or the likeand a contlnuousrihbon alongrespeetiveindividualpathsmergingata polntinwhichthetwomaterlalsaremovingin thesamedirectiommeamioraeverlnganddouhlinguponitselitheadvandngrlbbontoi'orm it into successive folded strips prior to its arrival at said point, power actuated means for ieedingtheribhonintheinitlalportionotits path at a rate substantially greater than that otthesheetadvanceaoastocompemate for the greaterlengthoirihhonrequiredtomatchthe lengthoisheetinginviewoi'thedouhlingoi therihbomsaidpoweraetuatcdmeansalsobeing eilectlve to feed the severed and iolded portlonsoitherihbonataslowerratematching that of the sheet substantially at said point of path merger, and means to: attaching successlve folded strips to the advancing sheet while the sheet and strips are advancing at matched rates.

20.1n a machine oi the type described. the combination of means for feeding in an endwise direction a sheet of bag material, means for severing successive sections from a continuous rihbonanddoublingeachoithemuponitseli'to Vance.

HALE W. PARRISH.

Images