US3618477A - Method of and apparatus for manufacturing bags - Google Patents

Abstract

THIS DISCLOSURE RELATES TO A PROCESS OF AND APPRATUS FOR MANUFACTURING BAGS OF THE TYPE HAVING A GUSSETED BODY AND A BOTTOM WHICH INCLUDES A PAIR OF BOTTOM PANELS AND A FIN TRANSVERSE THERETO BY CONVEYING EACH BAG ALONG A LINEAR FIRST PATH WITH ITS BOTTOM LEADING AND ITS FIN IN ANUPSTANDING POSITION, TRANSFERRING THE BAG TO A SECOND CONVEYOR BY ROTATING THE BAG AT LEAST NINETY DEGREES AND WHILE BEING CONVEYED ALONG A SECOND PATH SUBJECTING THE FIN, WHOSE INNERS SURFACES CARRY HEAT-ACTIVATABLE ADHESIVE, TO AN ELEVATED TEMPERTURE SUFFICIENT TO RENDER THE ADHESIVE TACKY AND FLOWABLE, AND THEREAFTER SUBJECTING THE FIN TO REGULATED PRESSURE ALONG A PREDETERMINED AREA AS THE TEMPERATURE DECREASES TO BRING THE INNER SURFACES OF THE FIN INTO INTIMATE CONTACT WHEREBY THE STILL FLOWABLE ADHESIVE FILLS PINHOLES AND THE LIKE PRIOR TO THE SETTING OF THE ADHESIVE THEREAFTER GROOVED CHILL ROLLS COOL THE ADHESIVE TO ITS SETTING TEMPRTURE DURING WHICH PERIOD THE FIN IS CONTINUALLY SUBJECTED TO REGULATED PRESSURE UNTIL THE ADHESIVE HAS SET.

Description

T. E. PIAZZE 3,618,471

METHOD OF AND APPARATUS FOR MANUFACTURING BAGS Nov. 9, 1971 5 Shets-Sheet 1 Filed. April 22, 1970 mvamow. THDMHS EPIHZZE mmanexs METHOD OF AND APPARATUS FOR MANUFACTURING BAGS Filed April 22, 1970 3 Sheets-Sheet 2 Nov. 9, 1971 T. E. PIAZZE +1?! CONVEYOR TH'UMns EPmzzE Nov. 9, 1971 E. pl ZZ 3,618,477

METHOD OF AND APPARATUS FOR MANUFACTURING BAGS Filed April 22, 1970 5 Sheets-Sheet 3 AIR SOURCE H13 04 31Gb 66 B2 is.

u 13] I33 130 127 22 A06 115 L A l'//////! l //)V\1D "H 64 5 Eb j 4 INVENTOR THOMAS E. PIAZZE TTOQNEYS United States Patent Office Patented Nov. 9, 1971 3,618,477 METHOD OF AND APPARATUS FOR MANUFACTURING BAGS Thomas E. Piazze, Mount Vernon, Ohio, assignor to Continental Can Company, Inc., New York, N.Y. Filed Apr. 22, 1970, Ser. No. 30,710 Int. Cl. B31b 49/04 US. C]. 9335 SB 25 Claims ABSTRACT OF THE DISCLOSURE This disclosure relates to a process of and apparatus for manufacturing bags of the type having a gusseted body and a bottom which includes a pair of bottom panels and a fin transverse thereto by conveying each bag along a linear first path with its bottom leading and its fin in an upstanding position, transferring the bag to a second conveyor by rotating the bag at least ninety degrees and while being conveyed along a second path subjecting the fin, whose inner surfaces carry heat-activatable adhesive, to an elevated temperature sufiicient to render the adhesive tacky and flowable, and thereafter subjecting the fin to regulated pressure along a predetermined area as the temperature decreases to bring the inner surfaces of the fin into intimate contact whereby the still flowable adhesive fills pinholes and the like prior to the setting of the adhesive. Thereafter grooved chill rolls cool the adhesive to its setting temperature during which period the fin is continually subjected to regulated pressure until the adhesive has set.

The present invention though primarily directed to the formation of so-called square bottom or automatic bottom bags is equally aplicable to the manufactuure of numerous other type bags which are normally subjected to pinholes, leakers or similar defects caused by the inability of known processes to assure intimate contact between adhesively coated inner surfaces of the bag bottoms while the inner surfaces are maintained in such intimate contact. One such typical process is disclosed in US. Pat. No. 2,648,- 263 issued in the name of Arthur W. Richens on Aug. 11, 1953. In accordance with the conventional method disclosed in the latter-noted patent, sheet material, such as paper or the like, lined or coated wholly or in part with thermo-plastic material is fed into a conventional bottom maker which progressively forms the sheet into a longitudinally seamed tube, severs the tube into tubular bag body blanks, and progressively forms the leading end of the body blank into a conventional square bottom.

Of particular interest is the fact that during the manufacture of each bag a fin thereof which is generally normal to a pair of bottom panels is clamed between a pair of heated jaws which keep the fin under pressure for fusion of the adhesive between inner faces of the fin. A plurality of such jaws are carried on a rotating wheel and each bag is carried by the wheel through approximately 270 degrees of revolution after which the jaws are opened and each bag is subsequently discharged, formed into a stack, and suitably packaged for shipment.

One major disadvantage of this process is directly attributable to the limited amount of time which each bag is held between the jaws during the heating of the fin. Sufiicient heat must be conducted through the paperstock material of the fin to elevate the temperature of the adhesive yet this must be done gradually in order not to char or burn the body blank. If, for example, the adhesive must be raised to a temperature of 500 F. an appreciable amount of time is in effect wasted to elevate the temperature of the adhesive and one must either increase the heat of the jaws or decrease the speed of rotation of the wheel carrying the jaws to reach the desired elevated temperature. Of course, increasing the heat of the jaws is undesirable because of the possibility of charring heretofore noted while a decrease in the speed of rotation of the jaw carrying wheel appreciably lessens production speeds.

A further undesirable characteristic of such processes is an unrecognition of the fact that the inner surfaces of the fin must be held in intimate contact during the time the temperature of the adhesive decreases from its elevated temperature to its lower setting temperature. In the conventional process heretofore described the jaws are uniformly heated to a desired elevated temperature and when each bag is released the adhesive is at its highest temperature which is above its setting temperature. Thus, as each bag is released the pressure of the jaws is discontinued and the inherent resiliency of the paperstock material as well as the folds thereof tend to automatically spread the inner surfaces of the fin resulting in pinholes, leakers, voids, etc. In other Words, if the adhesive has not reached its lowest setting temperature until sometime after having been released by the jaws there is absolutely no assurance that defects of the type heretofore noted will not occur and through experience it has been found that consistent quality is virtually impossible to achieve.

In accordance with the present invention it is a primary object to eliminate the disadvantages heretofore noted in conventional processes and apparatuses by transferring each bag from the heated jaws to a conveyor having a plurality of bank heaters followed by chilling units which are preferably in the form of grooved pairs of rollers between which the fin of each bag passes. As each fin passes between pairs of heaters the temperature of the adhesive is progressively elevated until the adhesive becomes tacky and flowable. Pressure is applied to opposite sides of each fin to urge the inner surfaces into intimate engaegment and any pinholes or voids which might otherwise occur are filled simply by the flowing of the adhesive under the influence of the applied pressure. Thereafter as the temperature decreases toward the setting temperature of the adhesive each fin passes through the grooved chilling rolls which maintain the inner surfaces of the fin in intimate contact while reducing the temperature to the setting temperature of the adhesive while still under pressure. In this manner the adhesive sets while the inner surfaces are in intimate contact and pinholes and similar voids are precluded.

A further object of this invention is to provide a novel process of and apparatus for manufacturing bags in the manner heretofore described wherein each bag is initially discharged from the heated jaws to a conveyor which feeds each bag with its bottom leading to a transfer mechanism, and the transfer mechanism includes means for gripping each bag bottom between a bottom panel and a face thereof and transferring the bag to a second conveyor along which each bag is conveyed with its body in a generally vertical plane to present each fin to the banks of heaters and the chilling rolls.

A further object of this invention is to provide a novel transfer mechanism of the type defined which includes gripping means in the form of a plurality of pairs of relatively movable gripping jaws which may be pneumatically or mechanically actuated between open and closed positions, and means for regulating the opening and closing times of the jaws to compensate for production speeds of the bototrn maker.

Still a further object of this invention is to provide a novel transfer mechanism of the type described wherein the first conveyor has a discharge end adjacent the transfer mechanism, and means are provided for selectively adjusting the distance between the discharge end of the first conveyor and the gripping jaws of the transfer mechanism to accommodate bags of different lengths.

With the above and other objects in view that will hereinafter appear, the nature of the invention will be more clearly understood by reference to the following retailed description, the appended claimed subject matter, and the several views illustrated in the accompanying drawings.

In the drawings:

FIG. 1 is a schematic top plan view of a novel apparatus constructed in accordance with this invention, and illustrates the progressive steps of forming suitable web material into body blanks, forming a bottom in each blank, discharging each blank in a horizontal plane with its bottom leading upon a first conveyor, transferring each bag to a second conveyor, and appropriately pre-heating, pressurizing and chilling each fin incident to the final completion of the bag bottom by a pasting and folding operation.

FIG. 2 is a schematic side elevational view of the apparatus of FIG. 1, and more clearly illustrates the first and second conveyors and the transfer mechanism therebetween.

FIG. 3 is a fragmentary plan view of a bag bottom of the square or automatic type, and illustrates a pair of bottom panels and an upstanding fin having gusseted sides, one of which is illustrated in a partially open condition.

FIG. 4 is a fragmentary end view of the bag bottom of FIG. 3 as viewed from right-to-left with both gussets being closed and illustrates adhesive disposed between inner surfaces of the plies forming the fin.

FIG. 5 is a fragmentary top plan view of the novel transfer mechanism of this invention, and illustrates one of a plurality of pairs of clamping jaws carried by a turret of the transfer mechanism which is rotated in the direction of the unnumbered headed arrow.

FIG. 6 is a fragmentary side elevational view of the transfer mechanism with parts broken away for clarity, and illustrates a pair of cams which are adjustable to regulate the opening and closing of the jaws.

FIG. 7 is a fragmentary side elevational view partly in cross section of another transfer mechanism, and illustrates a pair of jaws which are operated by an appropriate cam and cam follower.

FIG. 8 is a top perspective view of one of the chilling rolls of FIG. 1, and illustrates a pair of slotted supports in which are journalled a pair of the chilling rolls which through appropriate bolts and nuts permit adjustment to regulate the pressure applied to each bag bottom fin.

Reference is first made to FIGS. 1 and 2 of the drawings in which a novel apparatus of this invention is generally designated by the reference numeral 10 including as a portion thereof a conventional bottom former 11 of the type disclosed in the latter-noted patent to Arthur W. Richens. The bottom maker 11 is fed a web (not shown) which is formed into a tube by conventional means (not shown) located upstream which functions to essentiallly gusset sides of the tube T and provide the same with a longitudinal seam. The particular material from which the tube T is constructed may vary but essentially the tube T will include an outer ply of paperstock material which is wholly or partially provided on its inner surfaces with a coating of adhesive or a laminated liner such as polyethylene. Essentially the main requisite of the material from which the tube T is constructed is the provision on its inner surfaces of adhesive, Whether a coating or a laminate, which when subjected to an elevated temperature will become tacky and flowable yet at a lower temperature will set to effect a hermetic bond.

After the formation of the tube T, the latter is severed into tubular flattened body blanks B which are suitably supported by driven rollers (not shown) and are transferred to a first rotatable wheel 12 having a suitable drive shaft 13 and carying a plurality of gripping arms 14, only one of which is illustrated. Each blank B is subsequently transferred from the wheel 12 to a wheel 15 having a suitable drive shaft 16 and carrying a plu rality of heated jaws 17, 18, the latter of which is immovable and the former of which is movable. Only two of the jaws 17, 18 are illustrated in FIG. 2, but it is to be understood the wheel 15 may be provided with many more such jaws as in the manner of the latter-noted patent.

Each blank B is thereinafter transferred from the wheel 15 to a wheel 20 having an appropriate drive shaft 21, and carrying a plurality of clamping arms 22, only one of which is illustrated in FIG. 2.

Each blank B after having been transferred to the wheel 20 includes a body 24 (FIGS. 3 and 4) terminating at a square or automatic bottom 25. The body 24 includes a front face 26, a back face 27, and a pair of gussets 30, 31 which run the entire length of the bag along each side and extend into an upstanding fin 32. The gusset is shown partially expanded in FIG. 3 in order that the four plies thereof 3336 are more deadily illustrated. In addition to the four plies 3336, each gusset includes longitudinal folds 37, 38 and an innermost fold 40.

Due to the formation of the gussets 30, 31, it is to be noted that outboard of the fold lines 40, the fin 32 is formed by four plies 33-36 of material with appropriate adhesive A on inner unnumbered surfaces thereof, while inboard of the gussets or more particularly inboard of the folds 40, 40 the fin 32 is but of a two ply 33, 36 construction. Assuming that the gusset 30 is closed and in its normal position, it will be appreciated that upon the application of pressure to opposite sides of the fin 32, as is indicated by the unnumbered headed arrows in FIGS. 3 and 4, a greater amount of pressure will be applied across the thicker four- ply gussets 30, 31 than across the plies 33, 36 therebetween. In fact, it is because of this differential in thickness that pinholes or voids are normally created in the general area of the folds 40, 40 along the length of the fin 32, as is indicated by the reference characters P. Most normally such pinholes P or similar defects occur because of the thickness differential heretofore noted and the fact that the pressure is released prior to the adhesive A properly set with the inner surfaces of the various plies 33-36 in intimate contact. It is to the elimination of the pinhole P and the formation of a hermetic seal across the fin 32 to which the present invention is primarily directed. Once such a seal is properly formed the bottom 25 is completed, in a manner which will be described more fully hereinafter, by applying adhesive A across a bottom panel 41 of a pair of bottom panels 41, 42 and bringing the fin 32 and the panel 41 into pressure contact with the adhesive A. However, the hermetic seal and/or the primary seal is that achieved by the adhesive A while the bond between the fin 32 and the bottom panel 41 merely maintains the latter two elements in superimposed relationship to form a relatively flat bottom when the bag is open.

Referring again to FIGS. 1 and 2 of the drawings, the wheel 20 which corresponds to the wheel 65 of the latternoted patent forms a portion of a first conveyor which is generally designated by the reference numeral having a conveyor belt 51 entrained partially about the wheel 20, a suitably supported idler 52 and another idler 53. The shafts (unnumbered) of the rolls 52, 53 are suitably journaled 1n the framework (not shown) of the machine proper. Overlying a portion of an upper generally horizontal run 54 of the conveyor belt 51 is another belt 55 entrained about a pair of rollers 56, 57 which are likewise suitably ournaled in the machine framework. The purpose of the belt 55 is to cooperate with the upper run of the belt 54 to grip each blank B as it is released upon the counterclockwise movement of each of the clamping arms 22 thereby feeding each blank B in a generally horizontal plane along a linear path established by the upper runs 54 with the bag bottom 25 leading, and with the fin 32 in an upstanding position, as is indicated by the headed unnumbered arrow in the upper corner of FIG. 3. If desired or found necessary one or more pressure rollers 58- are supported above the upper run 54 of the conveyor 50 to make certain that each blank -B is properly conveyed toward the leftmost or discharge end of the conveyor 50 as viewed in FIG. 2 and delivered to a transfer mechanism which is generally designated by the reference numeral 60.

The transfer mechanism 60 includes a suitable frame having a lower support plate 62 ('FIGS. 2, 5 and 6) and an upper support plate 63 which are suitably joined to one another and to the machine framework by appropriate bracing. A main shaft 64 having a gear 65 fixed thereto by a key or similar conventional means is mounted for rotation upon the lower plate 62 by a conventional journal 66 and suitable bearings 67. A lower reduced end of the shaft 64 is threaded and receives a securing nut 68. An upper end of the rotatable shaft 64 includes a flange70 to which is fixed a circular turret 71. The turret 71 is rotated constantly or intermittently in a counterclockwise direction as viewed in FIGS. 1 and 5 in synchronism with the remaining drives of the apparatus through a right angle drive 72, a vertical shaft 73, a sprocket 74, and a drive chain 75 entrained about the sprocket 74 and the sprocket 65 secured to the shaft 64. If desired an adjustable idle sprocket 76 (FIG. 5 is conventionally adjustably mounted 171pon the lower plate 62 to adjust the tension in the chain Supported atop the turret 71 of the transfer mechanism 60 are four gripping or clamping mechanisms 77 of an identical construction and hence but one clamping mechanism 77 is illustrated in the drawings. The clamping mechanisms are preferably positioned about the periphery of the turret 71, and in an actual working embodiment of the invention four such gripping mechanisms 77 are carried by the turret 71. Each gripping mechanism 77 includes a plate 78 positioned in a horizontal plane and having a slot 80 which embraces an upstanding bar 81 suitably fixed to the turret 71. The bar 81 and the slot 80 accurately locate the plate 78 with respect to the turret 71 yet permit the plate 78 to be moved radially toward or way from the discharge end of the conveyor 50 to accommodate bag blanks B of different lengths. That is, as the length of bag blanks which are fabricated decreases the plate 78 shown in FIG. 5 is shifted to the right and fixed in a desired position while as the bag blanks B increase in length the plate 78 is shifted to the left as viewed in the same figure. The plate 78 is secured in any desired radial position by means of a pair of slots 82, 83 formed therein and appropriate nuts and bolts collectively designated by the reference numerals 85, 86. The nuts and bolts 85, '86 pass through openings (not shown) in the turret 71 and by merely loosening the same, shifting the plate 78, and retightening the nuts and bolts 85, 86 the plate 7 8 can be adequately secured as desired.

A pair of angle brackets 87, 88 are secured to the plate 78 and pivoted therebetween by a pin '90 is an arm 91 carrying a clamping or gripping jaw 92 which overlies a terminal end portion 93 of the plate 78 which functions as a fixed jaw to grip therebetween each blank B in the manner best illustrated in FIG. 6.

A pair of upstanding angle brackets 94, 95 are conventionally secured to the plate 78 between I the jaws 92, 93 and the angle brackets 87, 88. A fluid cylinder 96 is secured to the tops of the angle brackets 94, 95, and a piston rod 97 thereofis pivotally secured to the arm 91 by a generally inverted U-shaped bracket 98 and a pivot pin 100 in the manner best illustrated in FIG. 6. A spring (not shown) internally of the cylinder 97 normally biases the piston (not shown) thereof upwardly or in a counterclockwise direction as viewed in FIG. 6 to maintain the jaws 92, 93 in their relative open position. g

In order to close the jaws 92, 93 air is introduced into the cylinder 96 above the piston (not shown) from a pressurized air source ('FIG. 6) through a conduit 102, a universal coupling 103, an axial passage 104 in the shaft 64, one of a plurality of radial ports 106- in the shaft 64, a flexible conduit 107, a cam actuated solenoid valve 108, and a flexible conduit 110. An arm. 111 is pivoted at one end to the valve 108 and carries at its opposite end a cam follower 112 which pivots counter clockwise and as viewed in FIG. 5 to depress a switch 113 to open the valve 108 and permit the flow of pressurized air into the cylinder 96. Upon pivoting movement of the arm 111 in a clockwise direction the switch 113 is released closing the valve and venting the line to atmosphere resulting in the opening of the jaws 92, 93 under the influence of the spring within the housing 96.

The opening and closing of eachvalve 108 is controlled by a pair of cams 115, 116 (FIGS. 5 and 6). The cam includes a cylindrical portion or low side 117 followed by a rise 118, a high side 120, and a drop 121. The cam 116 likewise includes a cylindrical low side 122 (FIG. 6), followed by a rise 123, a high side 124 and a fall 125. The cams 115, 116 are stationary except for adju'stments which may be made for purposes to be described hereinafter, and as is best illustrated in FIG. 5 the cam follower 112 rides along the low sides 117, 122 of the respective ca-ms 115', 116 from approximately the 12 oclock position to the 5 oclock position at which time the switch 113 is open and the jaw 92 is likewise held open by the spring within the cylinder 96. As the follower climbs the rise 118 of the cam 115 the switch 113 is depressed resulting in the closing of the jaw 92 upon the opening of the valve 108. As the turret 71 continues to rotate counter-clockwise the cam. follower 112 rides along the high side 120 of the cam 115 and thereafter transfers therefrom and rides along the high side 124 of the cam 116 until it proceeds down the fall 125 at which time the switch 113 is open to vent the high pressure source to atmosphere and open the jaw 92. The purpose of the transfer of the cam follower from the high side 120 of the cam 115 to the high side 124 of the cam 116 is to regulate the opening and closing of the jaw 92 in a manner to be described immediately hereinafter.

The cam 116 is secured to a sleeve 127 surrounding the upper end portion of the shaft 64 which is, in turn, secured at its upper end portion to a gear 128. Likewise, the cam 115 is fixed to the lower end of a sleeve 130 whose 'upper end is likewise fixed to a gear 131. A pair of worm gears 132, 133 are in mesh with the respective gears 128, 131, and are suitably supported by brackets 134, ('FIG. 5) to the upper plate 63. Each of the worms 132, 133 includes a handle 136. Upon the rotation of the worm gear 132 in either a clockwise or a counter-clockwise direction like motion is imparted to the cam 116 through the sleeve 127 resulting in the movement of the fall 125 in a clockwise or counter-clockwise direction from the position illustrated in FIG. 5. If the worm gear 132 is rotated to move the fall 125 of the cam 11-6 counterclockwise as viewed in FIG. 5 the jaw 92 will remain closed for a longer period of time whereas opposite rotation results in the jaw 92 opening earlier. Likewise, by rotating the worm gear 133 to rotate the cam 115 clockwise the follower 112 will reach the rise 118 sooner resulting in the closing of the jaw 92 sooner than that illustrated while reverse rotation of the cam 115 will cause the jaw 92 to close at a position later than that illustrated in FIG. 5. Thus, by moving the fall 125 of the cam 116 clocklwise or counter-clockwise the point at which the jaw 92 opens can be selectively chosen whereas like movement of the rise 118 determines the position at which the jaw 92 will be closed.

Referring once again to FIGS. 1 and 2, the transfer mechanism 60 transfers each bag blank B toa second conveyor 135 which is entrained about a pair of idle sprockets 136, 137, and a pair of sprockets 138, 139 driven in synchronism from the drive chain of the apparatus 10 which is generally designated by the broken lines D in FIG. 2. Adjacent runs (unnumbered) of the conveyor 135 have faces disposed in a vertical plane and lie beneath the bottom panels 41, 42 of each blank B, as is best illustrated in FIG. 2. The conveyor 135 is of a conventional construction and includes a plurality of spring mechanisms backing up the adjacent runs urging the same toward each other to grip each of the blanks B. After the transfer of each of the blanks B to the conveyor 135 the blanks are conveyed with the gusset 31 leading, as indicated by the right handmost unnumbered headed arrow in FIG, 3 with the fin 32 and the faces or plies 26, 27 of the blank B in a generally vertical plane. By so supporting each of the blank B the fins 32 may be subsequently treated without interference by first subjecting the fins to a pre-heating operation or stage as the fins pass between pairs of heater banks 140 which though illustrated in 'FIG. 2 as a single unit are composed of a plurality of heaters which increase in temperature from right-to-left as viewed in FIG. 2. This gradual increase in temperature is effective to prevent the paperstock material from charring by avoiding an abrupt thermal-gradient and is progressively increased until the adhesive A reaches a tacky or fiowable condition which depending upon the adhesive itself as well as the paperstock material may range anywhere between 450 F. and 700 F. During the entire time the temperature of the adhesive A is elevated the plies 3336 of the fin 32 are maintained with their inner surfaces in intimate contact due to the pressure exerted thereon by the banks of heaters 140 which are conventionally spring-urged toward each other. It is because of this pressure and the flowable nature of the adhesive A at its elevated temperature, which is hereinafter referred to as its anti-pinhole temperature, that the adhesive is forced to flow and occupy any voids, fissures, pinholes, etc., and most particularly the pinholes in the areas P, P of FIG. 3. Once all such pinholes have been filled by the pressurized flo w of the adhesive A the fin 32 of each blank B is conveyed between a plurality of conventional chilling rolls arranged in pairs 141 through 144. The rolls (individually unnumbered) are suitably driven in the direction of the associated unnumbered arrows in FIG. 1 to convey the blanks B therethrough during which time the elevated temperature of the adhesive A is decreased appreciably toward the setting temperature of the adhesive A. As the adhesive A is chilled the pairs of rolls 141, 144 continue to apply pressure over the entire area of each fin 32 as it passes therebetween to maintain the inner surfaces of the plies 33-36 in continued intimate relationship over the entire width of the fins 32 and releasing this pressure only after the adhesive A has set. In other words, the initial preheating to an elevated temperature and pressure of the fins 32 prior to reaching the pairs of chilling rolls 141- 144 functions to flow the tacky adhesive into all fissures and pinholes while the subsequent continued pressure and reduction in temperature assures that the adhesive will set along all areas of the inner surfaces irrespective of the number of plies or the variation in thickness of the fins heretofore noted.

In order to assure that the pressure appled by the chill rolls is as effective as possible several alternatives or combinations thereof may be practiced in keeping with this invention, one of which is illustrated in FIG. 8 of the drawings to which attention is now directed. In FIG. 8 the pairs of rolls 141, 142 are illustrated as being supported from a pair of angle brackets 14-5, 146 which may be suitably supported from the framework of the apparatus 10. The angle brackets 145, 146 are provided with elongated slots 147, 148 respectively, and the lowermost two rolls (unnumbered) of the pairs 141, 142 are united by one or more tie bars 150 and suitable nuts and bolts, generally collectively designated by the reference numeral 151. By suitably adjusting the lower rolls of the pairs 141, 142 toward or away from the upper rolls thereof the gap between the rolls can be increased or decreased to apply the desired setting pressure to the fins 32.

In addition, the rolls of the pairs 141, 142 are preferably provided with a plurality of axially spaced outwardly opening circumferential slots which define lands and valleys with the lands of the two lowermost rolls shown in FIG. 8 being in horizontal registry with the valleys of the 8 two uppermost rolls illustrated in the same figure. By this construction the plies 33-36 of the fins 32 are more intimately urged toward each other.

Finally, instead of securing the lower rolls of the pairs 141, 142, in a desired position by the nuts and bolts 151, suitable adjustable spring means may be provided for continually urging the lowermost rolls toward the uppermost rolls in a conventional manner. However, the arrangement shown in FIG. 8 is preferable since it permits the lowermost two rolls to be readily removed for inspection and/ or repair purposes.

After the adhesive A of each fins 32 has set the blanks are continually conveyed from right-to-left in FIGS. 1 and 2 past a conventional paster which includes a solenoid operated valve (not shown) which functions to deliver the adhesive A' from a nozzle 156 upon the stippled area of the bottom panel 41 of FIG. 3.

After being conveyed past the paster 155 by the conveyor 135 each blank B passes a folding blade 157 which progressively folds the bottom panel 41 upwardly from its horizontal position to a vertical position in side-by-side relationship to the fin 32 after which the fin 32 and the bottom panel 41 of each blank B is passed through a pair of suitably driven pressure rollers 160, 161 thus completing the formation of the bottom 25 with the fin 32 now being adhesively secured to the bottom panel 41 by the adhesive A. It is to be noted that the primary hermetic seal is that formed by the bonding of the plies 33-36 to each other by the adhesive A whereas the adhesive A merely maintains each bottom panel 41 adhered to each fin 32 so that when the bag is opened it will automatically assume a flat square bottom which is desirable for packaging purposes.

After passing beyond the rollers 160, 161 each blank B contacts a folder bar 162 which is stationarily secured to the machine framework and contacts each blank -B at approximately its midpoint resulting in the progressive upward folding of each blank B to a horizontal plane once the bottom 25 has passed beyond the sprockets 136, 137. Each now-formed bag is deposited upon an upper run of a conveyor 163 for subsequent stacking, packaging and shipment to an ultimate consumer.

Reference is now made to FIG. 7 of the drawings which illustrates an embodiment of the invention which in lieu of the fluid actuation of the jaw Q2 of the transfer mechanism 60 utilizes solely mechanical means in the form of a stationary cam having a high side 171 and a low side 172. The cam 170 is attached to a flange 173 of a stationary shaft 174 about which a turret 175 is journaled for rotation. A sprocket 176 keyed to a hub 177 may be appropriately driven in a manner heretofore described to impart rotation to the turret 175 with respect to the cam 170.

As in the case of the transfer mechanism 60, the mechanism of FIG. 7 includes a plate 180 corresponding to the plate 78 except that it is provided with a cylindrical recess in which is received a spring 181 acting against the underside of a clamping arm 182 pivoted at 183 and carrying a cam follower 184 at an end opposite a clamping jaw 185. As the turret 175 rotates relative to the cam 170 the cam follower when upon the high side 171 of the cam 170 will maintain the jaw 18-5 in an open position which will progressively close during the movement of the follower 184 from the high side of the cam to the low side 172 thereof.

While preferred forms and arrangements of parts have been shown in illustrating the invention, it is to be clearly understood that various changes in details and arrangement of parts may be made without departing from the spirit and scope of this disclosure.

I claim:

1. In a process of manufacturing a bag of the type having a gusseted body and a bottom which includes a pair of bottom panels and a fin transverse thereto comprising the steps of conveying the bag along a linear first path in a first direction with the bag bottom leading and with the fin being generally normal to the first direction of bag travel, rotating the bag through at least ninety degrees to a position at which the fin is generally parallel to the first direction of bag travel, conveying the bag along a linear second path in a second direction parallel to the first direction with the fin being generally parallel to the first and second directions of bag travel, and adhering the fin to one of said pair of bottom panels during the movement of the bag along said second path.

2. The process as defined in claim 1 including the step of gripping one of said pair of bottom panels and a face of said bagbody incident to rotating the bag away from said first path.

3. The process as defined in claim 1 including the step of conveying the bag along the first path with the fin in upstanding relationship to the pair of bottom panels, conveying the bag along a first portion of the second path with the fin in upstanding relationship to the pair of bottom panels, and conveying the bag along a second portion of the second path with the fin in side-by-side relationship to one of said pair of bottom panels.

4. The process as defined in claim 1 wherein said bag body is disposed in a generally horizontal plane during the movement thereof along said first path and in a generally vertical plane during the movement thereof along at least a portion of said second path.

5. The process as defined in claim 1 wherein inner surfaces of the fin carry heat-activatable adhesive, including the steps of subjecting the fin to an elevated temperature sufiicient to render the adhesive tacky and flowable, and subjecting the fin to regulated pressure as the temperature decreases to bring the inner surfaces of the fin into intimate contact along a predetermined area whereby the still flowable adhesive fills pinholes and the like prior to the setting of the adhesive.

6. The process as defined in claim 1 wherein inner surfaces of the fin carry heat-activatable adhesive, including the steps of subjecting the fin to an elevated temperature sufiicient to render the adhesive tacky and flowable, subjecting the fin to regulated pressure as the temperature decreases to bring the inner surfaces of the fin into intimate contact along a predetermined area whereby the still flowable adhesive fills pinholes and the like prior to the setting of the adhesive, subsequently cooling the adhesive to its setting temperature, and continuing to subject the fin to regulated pressure until the adhesive has at least reached its setting temperature.

7. The process as defined in claim 2 including the step of conveying the bag along the first path with the fin in upstanding relationship to the pair of bottom panels, conveying the bag along a first portion of the second path with the fin in upstanding relationship to the pair of bottom panels, and conveying the bag along a second portion of the second path with the fin in side-by-side relationship to one of said pair of bottom panels.

8. The process as defined in claim 2 wherein said bag body is disposed in a generally horizontal plane during the movement thereof along said first path and in a generally vertical plane during the movement thereof along at least a portion of said second path.

9. The process as defined in claim 2 wherein inner surfaces of the fin carry heat-activatable adhesive, including the steps of subjecting the fin to an elevated temperature sufiicient to render the adhesive tacky and flowable, and subjecting the fin to regulated pressure as the temperature decreases to bring the inner surfaces of the fin into intimate contact along a predetermined area whereby the still flowable adhesive fills pinholes and the like prior to the setting of the adhesive.

10. The process as defined in claim 2 wherein inner surfaces of the fin carry heat-activatable adhesive, including the steps of subjecting the fin to an elevated temperature sufficient to render the adhesive tacky and flowable, subjecting the fin to regulated pressure as the temperature decreases to bring the inner surface of the fin into intimate contact along a predetermined area whereby the still flowable adhesive fills pinholes and the like prior to the setting of the adhesive, subsequently cooling the adhesive to its setting temperature, and continuing to subject the fin to regulated pressure until the adhesive has at least its setting temperature.

11. The process as defined in claim 3 wherein said bag body is disposed in a generally horizontal plane during the movement thereof along said first path and in a generally vertical plane during the movement thereof along at least a portion of said second path.

12. The process as defined in claim 3 wherein inner surfaces of the fin carry heat-activatable adhesive, including the steps of subjecting the fin to an elevated temperature sufiicient to render the adhesive tacky and flowable, and subjecting the fin to regulated pressure as the temperature decreases to bring the inner surfaces of the fin into intimate contact along a predetermined area whereby the still flowable adhesive fills pinholes and the like prior to the setting of the adhesive.

13. The process as defined in claim 4 wherein inner surfaces of the fin carry heat-activatable adhesive, including the steps of subjecting the fin to an elongated temperature sufficient to render the adhesive tacky and fiowable, and subjecting the fin to regulated pressure as the temperature decreases to bring the inner surfaces of the fin into intimate contact along a predetermined area whereby the still flowable adhesive fills pinholes and the like prior to the setting of the adhesive.

14. Apparatus for manufacturing a bag of the type having a gusseted body and a bottom which includes a pair of bottom panels and a fin transverse thereto comprising first means for conveying the bag along a linear first path in a first direction with the bag bottom leading and with the fin being generally normal to the first direc tion of bag travel, means for rotating the bag through at least ninety degrees to a position at which the fin is generally parallel to the first direction of bag travel, second means for conveying the bag along a linear second path in a second direction parallel to the first direction with the fin being generally parallel to the first and second directions of bag travel, and means for adhering the fin to one of said pair of bottom panels during the move ment of the bag along said second path.

15. The apparatus as defined in claim 14 including means for gripping one of the pair of bottom panels and a face of said bag body incident to rotating the bag away from said first path.

16. The apparatus as defined in claim 15 wherein said gripping means is carried by said rotating means.

17. The apparatus as defined in claim 15 including means for deactivating said gripping means incident to the travel of said bag along said second path by said second conveying means.

18. The apparatus as defined in claim 15 wherein said rotating means is a turret carrying said gripping means, and said gripping means is a pair of relatively movable gripping jaws.

19. The apparatus as defined in claim 15 wherein said first conveying means has a discharge end adjacent said rotating means, said gripping means is carried by said rotating means past said discharge end, and means for selectively adjusting the distance between said discharge end and said gripping means to accommodate bags of different lengths.

20. The apparatus as defined in claim 15 wherein said first conveying means has a discharge end adjacent said rotating means, said gripping means is a pair of relatively movable jaws carried by said rotating means past said discharge end toward said second conveyor means, means for closing and opening said jaws, and means for selectively adjusting the time interval during which the jaws are closed.

21. The apparatus as defined in claim 15 wherein said 11 first conveyor means conveys said bag body in a generally horizontal plane during the movement thereof along said first path, and said second conveyor means conveys said bag body in a generally vertical plane during the movement thereof along said second path.

22. The apparatus as defined in claim 21 wherein said second conveyor means includes means for gripping 0pposite faces of said bag body beneath said pair of panel portions.

23. The apparatus as defined in claim 21 wherein said gripping jaws grip the bag between one of said pair of bottom panels and a face of said bag body with said fin in upstanding relationship 24. The apparatus as defined in claim 22 wherein inner surfaces of the fin carry heat-activatable adhesive, the apparatus further including means for subjecting the fin to an elevated temperature suflicient to render the adhesive tacky and flowable during the movement of the bag by said second conveyor means, and means subsequently sub- 12 jecting the fin to regulated pressure as the temperature decreases to bring the inner surfaces of the fin into intimate contact along a predetermined area whereby the still flowable adhesive fills pinholes and the like prior to th setting of the adhesive.

25. The apparatus as defined in claim 24 wherein said adhering means includes means for bringing one of said pair of bottom panels to a generally vertical position in contact with said fin after the application of adhesive therebetween.

References Cited UNITED STATES PATENTS 6/1963 Haslacher 9335 SB 8/1966 Finke et a1. 93-35 SB X BERNARD STICKNEY, Primary Examiner

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