US2467879A - Bagmaking machine - Google Patents

Description

April 19, 1949.

. c. K. BILLEB BAG MAKING MACHINE 3 Sheets-Sheet 1 Filed lay 17, 1945 A rToR/VEYs.

April 19, 1949. c. K. BILLEB BAG KING MACHINE 3 Sheets-Sheet 2 Filed lay 17, 1945 A rroRlvzrs.

April 19, 19.49. c. K. BILLEB 2,467,879

BAG MAKING MACHINE Filed lay 17, 1945 3 Sheets-Sheet s ATTORNEYS.

Patented Apr. 19, 1949 BAGMAKING MACHINE Clyde K. Biileb, Shorcwood, Wis., assignor to Milprint, Inc., Milwaukee, Wis., a corporation of Delaware Application May 17, 1945, Serial No. 594,272

4 Claims. (01. 154-42) The present invention relates generally to improvements in the art of producing flat pressurev sealed articles in rapid succession, and relates more specifically to an improved system of manufacturing successive bags, pouches or envelopes from a continuous ribbon of sheet stock such as thermoplastic material, paper or the like.

The primary object of my invention is to provide an improved system of rapidly and effectively producing a succession of bags or pouches, with least waste of material and at minimum cost.

Many different types of machines and systems for producing successive bags or pouches from thermoplastic sheet material such as cellophane or Pliofilm, and from paper having local adhesive areas applied thereto, have heretofore been proposed and used commercially with varying degrees of success, but none of this prior equipment has proven entirely satisfactory for various reasons. Most of the prior bag making machines are unable to function so as to'produce successive perfect articles at high speed, primarily because the apparatus does not provide for a sufficient period of proper heat and pressure application to the seams or joints which-are necessary in the production of the bags or pouches. Others of the previous mechanisms for automatically manufacturing a succession of bags or the like, were relatively complicated and unreliable in operation, and could not be effectively utilized to operate upon different types of stock material. Still others of the prior assemblages for producing such items, could not be readily manipu- 2 which is capable of being utilized to operate efiectively with any sheet stock having pressure seal-. able local areas or continuous coatings thereon.

These and other specific objects and advantages of the invention will be apparent from the following detailed description.

A clear conception of the several features constituting my improvement, and of the mode of constructing the mechanism and of operating a system embodying the invention, may be had by referring to the drawings accompanying and forming a part of this specification wherein like reference characters designate the same or similar parts in the various views. 7

Fig. 1 is a diagram of a typical bag producing system embodying the invention, depicting diagrammatically the successive steps involved from start to finish;

Fig. 2 is a somewhat diagrammatic considerably enlarged transverse section through the improved pressure and heat applying bar assembly and dwell producing mechanism for sealing the transv verse joints of the rapidly advancing stock ribbon;

Fig; 3 is a somewhat enlarged end view of the jumping ribbon tensioning or draw roll assemblage utilized in the improved system when operating with non-thermoplastic stock having local thermoplastic or adhesive strips applied transversely to the ribbon;

Fig. 4 is an enlarged fragmentary side elevation of the improved dwell producing mechanism for the sealing bars, showing a fragment of the latter swung into the plane of the view;

Fig. 5 is a similarly enlarged end view of the mechanism shown in Fig. 4, illustrating the same in two different positions of adjustment in heavy and light lines respectively; and

It is therefore a more specific object of the present invention, to provide improved bag making mechanism which obviates all of the above mentioned objectionable features, and which is extremely flexible in its adaptations and reliable in operation.

Another specific object of this invention is to provide an improved bag or pouch fabricating system adapted to convert a rapidly advancing Fig. 6 is a somewhat diagrammatic central vertical section through the draw roll and pressure applying mechanism for sealing the transverse joints of the travelling ribbon, the section being taken in the longitudinal plane of advancement of the stock ribbon. I

While the invention has been shown and described herein as being advantageously applicable to a system for'for producing successive bags from'a continuous ribbon of stock traveling at high speed and adapted to be heat sealed and severed into a succession of bags of any desireddefinite length, it is not my desire or intent to unnecessarily restrict the scope or to limit the utility by virtue of this specific and typical embodiment.

Referring particularly to. Fig. 1 of the draw-- 3 trated. diagrammatically therein, comprises general a stock ribbon supply or mill roll 9 conslsting of a continuous ribbon 9 of stock; a series of guide rollers l coacting with the ribbon 9 to guide and conduct the same past a transverse glue strip applier or cross-pester II and a longi-' tudinal adhesive applier or center seam glue wheel [2 in rapid succession; a former disk l3 subsequently cooperable with the ribbon 9 to fold the opposite longitudinal glue coated edge portions thereof inwardly into overlapping coaction with each other, and to direct the folded ribbon horizontally; two laterally spaced pairs l4, 15 of lifting or jumping draw rollers adapted to coact with the horizontal folded stretch of the ribbon 9 after it leaves the former disk l3; a set of upper and lower heat sealers or heated transverse pressure bars 19, ll cooperable with the local transverse adhesive strips applied to the ribbon 9 by the cross-paster H, to seal the transverse areas of the folded travelling stock; another set of cooperating draw rollers l8 pressingly coacting with the longitudinal seam and with the transversely heat sealed ribbon 9; a

cut-01f device l9 for severing the advancing seam sealed ribbon into successive bag lengths; a final set of draw rollers 20 for delivering the severed lengths 2! of the ribbon 9 to a series of revolving speed increasing segment sets 22, 23 cooperating with the severed bag lengths M to momentarily augment the speeds threof and to provide time for finally tucking and gluing the successive bag bottoms; a set of rotating tucking and tuck clamping cylinders 24 coacting with a glue wheel 25 and with a final press roll 26 to tuck and glue the bag bottoms; and a stacking receptacle 2? for the finally completed bags 28.

The cross-paster H and seam glue .wheel I2 cooperate with transverse glue wheels 29, 30 respectively, in a well known manner to apply transverse and longitudinal strips of adhesive to the stock ribbon 9 at the desired localities when the stock is of a non-thermoplastic type and therefore not adapted to be heat sealed throughout its entire area; but when thermo-plastic stock is used, at least the cross-paster Il may be omitted. The former disk I3 which is adapted to fold the opposite longitudinal edges of the ribbon 9 inwardly to provide a tubular continuous ribbon of advancing stock, functions automatically as the ribbon 9 is drawn past the revolving disk, and this former as well as the crosspaster H and glue wheels i2, 29, 30 are all of well known structure and operation adapted to cooperate with stock ribbons of various widths and lengths, and consisting of diverse materials such as cellophane, Pliofilm, a paper, or the like.

The two laterally spaced sets or pair l9, ii of initial draw rolls, are of special construction as shown more in detail in Figs. 3 and 6, and each pair [4, l5 comprises an upper roll having opposite continuous annularend flanges 3| of slightly greater diameter than the intervening roll, and a lower roll having opposite concentric surfaces 32 of lesser diameter provided with local cam projections 39 adapted to coact with the peripheral cylindrical edges of the corresponding flanges 3| of the adjacent upper roll. These cam projections 33 of the roll set I are angularly advanced relative to the corresponding cam projections 33 of the other draw roll set l5, and the rolls of each pair [4, l5 are normally urged toward each other by compression springs 39 thus causing the flanges 9| to normally contact and roll upon the adjoining surfaces 92 when the projections are inactive as at the right of Fig. 3. However, when the projections 99 of either roll set l4, l9 are active as shown at the left of Fig. 3, the upper roll is momentarily lifted away from the lower roll of the set; but the rolls of only one set l4, l5 are adapted to be thus momentarily separated at a predetermined time thus maintaining at least one pair H, 15 active as draw rolls at all times. The end bearings for the draw roll sets l4, I! are mounted in a main frame 35, and the lower draw rolls are adapted to be constantly rotated from a power shaft 36 through a train of gears 31, in the directions indicated; and when the draw roll sets l4, ii are functioning normally, and in properly timed relation to the speed of travel of the ribbon 9. the rolls of the alternate sets l4, l5 will jump or be automatically separated as each of the successive transverse glue strips applied by the cross-paster H passes therebetween, thus preventing the advancing ribbon from sticking to the initial draw rolls while constantly maintaining the draw pull on the ribbon 9.

Th complementary set of upper and lower heat sealers or heated transverse pressure bars 69, H which is cooperable with the local transverse adhesive strips applied to the ribbon 9 by the cross-paster ll so as to seal the successive transverse areas of the tubular advancing stock,

and the mechanism for moving these bars l6, H, are also of improved construction and operation and constitute an important feature of my invention. Each of these bars li, I1 is provided with an electrically heated elongated pressure plate 39 comprising a constantly heated strip of metal having a roughened contact face and being energized in any suitable'manner, and each bar 86, I! is slidably mounted in a cradle 39 and is constantly urged toward the other bar by means of a number of compression springs 49, see Figs. 2 and 6. Each cradle 39 is also provided with four rigid laterally projecting arms 9| each having an anti-friction bearing 42 mounted therein, and these bearings 42 coact with crank pins d3 projecting inwardly from the sides of two pair of intermeshing gears 49, 45 which are journalled for rotation upon the main frame 35 as shown in Figs. 2, 4 and 6. The upper gears II are rotatable by the lower gears 45 and the latter are drivingly interconnected by idler gears 46 so that rotation imparted to any one of the gears 44, 45 will obviously be simultaneously transmitted to all of the others and will cause-the crank pins 43 to revolve in unison thereby also causing the cradles to revolve in orbits while their bars l6, H are always maintained parallel to each other with their pressing faces disposed in horizontal planes at all times, as best shown in the motion diagram of Fig. 2. While the bars l6, l! are being moved rearwardly out of engage ment with each other the springs 49 will push them outwardly in their carrier cradles 39 as far as the stop plates 41 will permit; but as the bars I 6, l1 engage the intervening ribbon 9 and are moved forwardly, they recede within their cradles 39 and the heater plates 99 resiliently engage and heat and press the adhesively coated local transverse areas of the ribbon 9 during a dwell period D, see Fig. 2.

As shown in Figs. 4, 5 and 6, the lowergears 45 at the left of the heat sealing assemblage, are adapted to be positively rotated so as to provide maximum dwell periods D, by means of a special motion transmitting mechanism comprising a revolving slide 46 centrally attached to the shaft 49 to which the adjacent gear 46 is also secured, and a crank 66 having a roller 6| mounted upon its revolving crank pin 62 and coacting with the rectilinear slot 53 of the adjacent slide 46. The shaft 49 is mounted in an anti-friction bearing 54 carried by the main frame 35, while the crank 66 is secured to one end of a counter-shaft 55 which is journalled for rotation in an antifriction bearing '6 carried by a normally fixed but adjustable bracket 51. A gear 66 is secured to the outer end of the counter-shaft 66 and meshes with a gear 69 carried by the adjacent outer end of a horizontal shaft 66 which is journalled for rotation in the main frame 36: and the bracket 51 is swingably adjustably mounted uponthe shaft 60 and is provided withan armate adjusting slot 6! with which a clamping cap screw 62 is cooperable in order to lock the bracket 61 in properly adjusted positions. The cap screw 82 penetrates the slot 6| and coacts with a boss 63 rigidly attached to the main frame 36. so that by loosening the screw 62, the bracket 61 may be swung about the shaft 60 as a pivot and the shaft 65 may thus be shifted toward and-away from the axis of the shaft 49. The transverse shaft 60 may be driven-directly from the power shaft 36 through gearing 64, and is constantly rotatlng during normal operation of the machine.

With this assemblage of elements, the heating and pressure applying bars i6, ll may be caused to travel quickly when being carried rearwardly and while inactive, and to advance slowly during the dwell period D and while travelling forwardly in contact with the ribbon 8. These rates of rearward travel of the bars it, H and the duration of the dwell period, may both be varied by merely adjusting the position of the bracket 51! and hence the location of the crank shaft 55 relative to the axis of the shaft 49, with the aid of the slot ti and clamping screw 62 "coacting therewith, thus permitting the mechanism to be adapted for proper cooperation with bags of various lengths and with ribbons. 9 travelling at high speeds. By adjusting the shaft 65 so as to cause its axis to coincide with that of the shaft 69, the forward and return movements of the sealing bars i6, ll will be substantially equalized; but as these shaft axes-are separated more and more, the return speed of the pressure bars will increase while the forward speed will be correspondingly decreased thus also increasing the dwell period D, that is the duration of the sealing period. While the mechanism for effecting this adjustment has been shown in'several positions in Fig. 5, in heavy and light lines respectively, the bracket 51 would normally be in approximately the position shown in the heavy lines and would not ordinarily be swung as far to the right as actually indicated by the light line position.

The draw rolls i8 which are disposed forwardly of the transverse orbitally moving sealing bars i6, i1, may be of a well known type wherein the lower roll is constantly positively rotated with the aid of suitable gearing, while the upper roll is mounted in slidable bearings and is resiliently urged toward the lower roll by means of adjustable compression springs 65, as indicated in Fig. 6. These draw rolls l8 are journalled for rotation in bearing boxes 66 coacting with the main frame 35, and the draw rolls l6 besides maintaining the advancing ribbon 6 in taut condition, also'serve to press the adhesive coated longitudinal seam formed by the opp iteoverlapped side portions of, the ribbon 6, into sealing condition. The transverse areas which finally constitute the bottom closures of the successive bags and the longitudinal seams of the bags, are thus completed in succession while the ribbon 6 is still in tubular and continuous 'form, and the draw rolls l6 thereafter advance the ribbon 9 toward the cut-oi! device ll.

The cut-oi! device I! may be of any well known type adapted to shear the ribbon 9 into successive equal lengths while advancing at high speed, and the successive severed lengths 2| of the tubular stock are withdrawn from the zone of cutting by another set of ordinary draw rolls 2!! and are delivered toward the first set of speed accelerating segments 22, see Fig. 1. These speed increasing segments 22 are also of well known construction, and after somewhat accelerating the speed of travel of the severed length 2|, the segments 22 deliver the successive lengths to a second set of similar accelerating segments 23 which function to still further increase the speed of advancement of the bag lengths 2i and to deliver them in succession to the final tucker and bag finishing rolls or cylinders 24. The acceleration of the bag lengths 2| after being severed from the ribbon 9, is necessary in order to provide ample time for the cylinders 24- to finish the bags 28; and the tucking cylinders are likewise of well known construction and cooperate with the glue wheel 25 and pressing roll 26 to fold or tuck the previously sealed ends of the successive lengths 2i, to apply adhesive to the tucks, and to press the tucks to the adjacent bag walls, thereby finishing the bags 28 and delivering the completed articles in rapid succession to the stacking receptacle 21.

While the normal operation or successive steps of my improved bag making system should be quite apparent from the foregoing detailed description, a short rsum thereof will be given.

During such normal operation, the draw rolls i4, I

i5, i6, 20 and the segments 22, 23 will berotating to withdraw the stock ribbon 9 from the mill roll 8, and to advance the same past the cross-paster ii, longitudinal seam glue wheel i2, and the former disk H3 in succession. The speedof travel T wheel i2, a longitudinal glue strip is likewise applied to one edge of the ribbon. When advancing past the former disk l3, the opposite longitudinal edge portions of the continuous ribbon 9 are folded'inwardly and overlapped with the longitudinal glue strip between the superimposed folds, and the tubular ribbon thus produced is subsequently drawn past the initial draw roll sets ll, i5. 1

While advancing past these roll sets l4, IE it is desirable to avoid contact between the rolls and the externally exposed transverse strips of adhesive which have been applied to the ribbon 9 by the cross-paster H, and the cam projections 33 associated with the lower rolls l4, l5 and coacting with the flanges 3| of the upper complementary draw rolls, postively prevent such undesirable contact between the draw rolls and the glue coated areas. However, by virtue of the relative positions .of the projections 33 on the strip area.

aseaarc several roll sets it, it, only the rolls of one at these sets will be separated at a given instant, and the rolls of one set l4, It will therefore be effective at all times, thus insuring constant draft tension on the ribbon 9. After passing the initial draw roll sets M, it, the tubular ribbon 9 is delivered to the transverse sealing zone be tween the heated pressure bars it, t? and the heatin and pressing plates 38 of these bars clamp the successive adhesive cross-strips therebetween, and firmly seal the tubular ribbon at these strips. By properly adjusting the bracket 5? and hence the position of the crank shaft relative to the axis of the shaft it, the plates may be caused to accurately cooperate with the successive transverse glue strips of the ribbon and the dwell period D which is produced by the orbital travel of the bars as, ll insures most cf fective sealing of the successive cross-seams even when the ribbon a is travelling at high velocity.

As the cross-seamed ribbon 9 proceeds beyond the heat sealing zone, the draw rolls it become effective to press the longitudinal seam oi the constantly advancing tubular ribbon, whereupon the ribbon is delivered to the cut-E device it and is severed into successive equal bag lengths at each having one end closed by a transverse sealed The successive severed lengths it are thereafter deliveredby the final draw rolls Ed to the acceleratin segments 22, 23 which rapidly remove the lengths 2i from the zone of cutting and deliver them in succession to the final tucking and gluing cylinders The finished bags 26 are delivered in rapid succession by the cylinders 2% past the press roll 26 to the stacking receptacle 2?, thus providing a system for automatically and effectively converting the constantly and rapidly advancing stock ribbon 9 into completed bags 28 of uniform length and of durable construction.

From the foregoing detailed description of the specific construction and operation of the improved bag making apparatus, it should be apparent that my present invention provides an improved system of fabricating successive bags 28 of any desired length in rapid succession and without waste of material. The improved mechanism for heating and pressing the successive cross-seams, provides for most effective and accurate clamping and pressing of the transverse adhesively coated areas, regardless of the speed of operation or of the bag lengths; and the pressure applied during each prolonged dwell period D is substantially uniform at all times. The distance travelled by each cross-seam during the dwell and sealing period D is always equal, but

the time involved in each dwell varies slightly in accordance with the speed of operation of the mechanism, and may be prolonged by merely adjusting the bracket 51 with the aid of the clamping screw 62 coacting with the slot 6!. The parallel disposition and orbital movement of the bars l6, l1 combined with the slow forward and quick return motion thereof, result in most ef-. fective sealing pressure application at all times, and may be utilized to commercially seal seams while the ribbon 9 is travelling approximately fifteen thousand feet per hour, and such speeds have heretofore been impracticable with revolving and reciprocating sealers.

The jumping draw roll sets l4, l may also be utilized to good advantage when operating upon non-thermoplastic stock to which local adhesive cross strips are applied in spaced succession, but itis tobe noted that the use of the improved heat sealing bars it, ll is not limited to operation on such stock, and these bars to, H and the mechanisms for actuating the same may be just as advantageously employed when operating with thermoplastic ribbon stock such as cellophane, "Pliofllm, or the like. The fact that the heat sealing is accomplished before the ribbon 9 is severed into sections or lengths 2i, eliminates waste of material due to sticking of the severed length to the heat sealing bars, and the draw rolls Eb, it on opposite sides of the sealing zone positively prevent the ribbon stock from clinging to the pressure bars it, ll since they maintain the intervening portion of the ribbon t in stretched and taut condition. The improved mechanism also obviates all back lash or whip in the ribbon stools, at all times, even when operating at high speed and with delicate material; and while the improved system may utilize final tucking and gluing of the bag bottoms, as shown, it is just as applicable to the manufacture of bags or pouches wherein such tucking is omitted.

The present improvement has proven highly successful and satisfactory in actual commercial use, and is exceedingly flexible in its adaptations; and the improved mechair'sm after having been properly adjusted requires no great attention and functions automatically. The assemblage is obviously simple, compact, and durable in construction, besides being highly efficient in operaticn especially when operating at high speed, and very little waste of material occurs after proper initial adjustments have been made. Such adjustments may also be readily effected while the machine is in operation, and change-over from bags 2% of one length to shorter or longer bags may also be quickly and conveniently accomplished. i

It should be understood that it is not desired to limit this invention to the exact steps of the system or to the precise details of construction and operation, herein shown and described, for various modifications within the scope of the appended claims may occur to persons skilled in the art.

I claim:

1. In a bag making system, means for advancing a flattened tubular ribbon of material longitudinally along a rectilinear path, a pair of elongated parallel carrier cradles simultaneously revolvable at like speeds but in opposite directions entirely on opposite sides of said path, a sealing bar carried by an intermediate portion of each of said cradles and revolvable therewith on the same side of said path as its respective cradle, said bars having flat faces spanning and engageable with the opposite sides of successive transverse areas of the advancing ribbon and being suspended from their carrier cradles so as to constantly maintain said faces parallel to said path, two sets of oppositely rotatable gears disgated parallel horizontally disposed cradles simultaneously revolvable at like speeds but in opposite directions entirely on opposite sides or said path, a sealing bar carried and revolvable by the midportion of each of said cradles on the same side of said path as its respective cradle, said bars having flat faces spanning and engageable with the opposite sides of successive transverse areas of the advancing ribbon and being resiliently retractable relative to their carrier cradles while contacting the ribbon and with said races constantly maintained parallel to-said path, two sets of oppositely rotatable intermeshing gears disposed on opposite sides of said path, each gear or each set having a crank pin coacting with an end of the cradle disposed on the corresponding side of said path for revolving said cradles, driving means coacting with said gears to cause said bars to advance with a slow forward and a quicker return motion, and means cooperating with said driving means to vary the speed of movement of said cradles and the distance between successive ribbon contact areas.

3. In a bag making system, means for advancing a flattened tubular ribbon of material longitudinally along a rectilinear path, a pair of elongated parallel carrier cradles simultaneously revolvable at like speeds but in opposite directions entirely On opposite sides of said path, a sealing bar carried by an intermediate portion of each of said cradles and revolvable therewith on the same side of said path as itsrespective cradle, said bars having flat races spanning and engageable with the opposite sides of successive transverse areas of the advancing ribbon and being suspended from their carrier cradles so as to constantly maintain said faces parallel to said two sets of oppositely rotatable intermeshln gears disposed on opposite sides of said path, each gear of each set having a crank coacting with an end of the cradle disposed on the corresponding side of said path for revolving said cradle, a revolving slide for driving said gears, a driving crank having a revolving pin coacting with said slide, an adjustable bracket rotatably supporting said driving crank, and gearing for rotating said driving crank, said bracket being adjustable to vary the distance between the axes of revolution of said slide and pin and to thereby vary the contact periods or said bars with the ribbon.

4. In a bag making system, means'for advancing a flattened tubular ribbon of material longitudinally along a rectilinear path, a pair of elongated parallel cradles simultaneously revolvable at like speeds but in opposite directions entirely on opposite sides of said path, a sealing bar carried by an intermediate portion of each of said cradles and revolvable therewith on the same side of said path as its respective cradle, said barshaving flat faces spanning and engageable with the opposite sides of successive transverse areas of the .advancing ribbon and being suspended from their carrier cradles so as to constantly maintain said faces parallel to said path, oppositely rotatable intermeshing gears disposed on opposite sides of said path, each gear having a,

crank pin coacting with an end of the cradle disposed on the corresponding side of said path for revolving said cradle, a revolving slotted slide for driving said gears, a driving crank having a revolving roller coacting with the slide slot, a bracket swingably adjustable about an axis and rotatable supporting said driving crank, and a gear journalled in said bracket for rotating said driving crank, said bracket being adjustable about said axis to vary the distance between the axes of revolution of said slide and roller and to thereby pat at vary the contact period of said bars with the advancing ribbon.

- CLYDE K. BILLEB.

' REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Salilsbers Dec. 14, 1943

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