US2324393A - Bag making machine - Google Patents

Description

July '13, 1943. J. HOHL ET AL BAG MAKING MACHINE Filed Sept. 13, 1939 16 Sheets-Sheet l m N R m T A J. HOHL ET AL BAG MAKING MACHINE Filed Sept. 13, 1959 Jul y 13, 1943.

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July 13, 1943. J. HOHL ET AL BAG MAKING MACHINE Filed Sept. 13, 1939 16 Sheets-Sheet 7 A TTORNEYS.

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ATTORNEYS Patented July 13, 1943 UNITED STATES PATENT OFFICE BAG MAKING MACHINE Application September 13, 1939, Serial No. 294,734

44 Claims.

Our invention relates to apparatus for making bags or containers adapted to be filled with oil or other liquids or materials. The apparatus as herein disclosed is particularly adapted for manufacturing bags from webs of thin, flexible, impervious, transparent material such as Pliofilm, Cellophane or the like, with reinforcing strips or panels of like material on opposite sides of the bag, the latter being further reinforced by paper or other sheet material covering the intermediate sides of the bag. A bag of this character is disclosed in the patent to Hohl and Bjering, number 2,233,704, March 4, 1941.

An object of the present invention is to provide a new and practical machine for continuously manufacturing bags of the character indicated and particularly bags such as disclosed in said copending application.

A further object of the invention is to pro vide such a machine in which the main web or film and the reinforcing strips of film are continuously fed forward, brought into assembled relation, the reinforcing strips heat sealed to the main web or film, the reinforced web as it advances being drawn over a shaping die and shaped to tubular form with its edges overlapping and then heat sealed, the tube thus formed being flattened with a concomitant infolding or plicating of the sides of the tube as it advances, reinforcing webs of paper or the like being thereafter adhesively attached to the opposite flat sides of the collapsed tubular web, the latter thereafter heat sealed transversely at intervals and finally severed at said transverse sealing areas to form individual bags.

A feature of the invention relates to the novel apparatus for applying the reinforcing strips of film to the main web and heat sealing said strips along their margins.

A further feature of the invention relates to the heat sealing means for continuously sealing the overlapping edges of the main web to form a tubular body.

A further novel feature of the invention relates to the means for pleating or infolding the sides of the tube and flattening the latter.

Another object of the invention is to provide novel means for cross-sealing the tube which is held stationary at the cross-sealing station, and to further provide novel tension and take-up mechanism for taking up the slack during said cross-sealing operation.

A further object of the invention is to provide means for effecting a supplemental cross-sealing operation after the bags have been severed,

in order to insure a perfect seal. An aim of this supplementary sealing operation is to overcome the difficulties incident to obtaining a reliable seal with a varying number of plies or layers of the material at different points transversely of the bag, and particularly to insure a perfect seal of the multiple layers at the infolded portions of the bag.

Other objects of the invention will appear hereinafter.

Referring to the accompanying drawings:

Fig. 1 is a diagrammatic side elevation view of a machine constructed in accordance with' our invention;

Figs. 2, 3 and 4 are detail views of a latch mechanism for lifting and holding the seaming rolls and glue rolls in an inoperative position;

Fig. 5 is a diagrammatic view in side elevation illustrating the various rolls from which the webs are fed and the manner in which the webs are assembled and also illustrating the sealing and severing mechanism;

Fig. 6 is a diagrammatic plan view of the apparatus shown in Fig. 5;

Fig. 7 is a plan view of a cross-sealing device;

Fig. 7A is a plan view of a modified form of cross-sealing device;

Fig. 8 is a plan view illustrating the manner in which a flattened tube is cross-sealed with the sealing device shown in Fig. 7 and severed into individual bags;

Fig. 8A illustrates the cross-sealing with the sealing device of Fig. 7A and the severance at the cross-seal;

Fig. 83 illustrates the final cross-sealing of the bottom of the bag, following the operation indicated in Fig. 8A;

Fig. 9 is a cross-sectional view of a bag partly collapsed;

Fig. 10 is a diagrammatic plan view showing the shaping mandrel, the tube sealing means. and the folding mechanism;

Fig. 11 is a side elevation of such apparatus;

Fig. 12 is a fragmentary side elevation showing the forward end of the shaping mandrel and the rolls for pleating or infolding the sides of the bag;

Fig. 13 is a fragmentary detail view of a hinged plate shown in Figs. 10 and 11;

Fig. 14 is a plan view of the left-hand portion of the machine including the tube forming and sealing apparatus, means for applying the reinforcing strips of film, and the means for folding and flattening the tube;

Fig. 15 is a fragmentary part sectional plan view, showing particularly the rolls of reinforcing film strips and seaming means for sealing the strips to the main film;

Fig. 16 is a fragmentary plan view of the infolding rolls;

Fig. 1'7 is a detail view of a feed roll;

Fig. 18 is a plan view of that portion of the machine to the right of that which is shown in Fig. 1

Fig. 19 is a fragmentary sectional plan of the cross-sealing means;

Fig. 20 is a cross-sectional elevation showing the main driving shaft, counter-shaft and clutch mechanism;

Fig. 21 is a sectional plan of the same at the line 2l-2l on Fig. 20;

Fig. 22 is an and elevation of the mechanism shown in Figs. 20 and 21;

Fig. 23 is a part sectional side elevation illustrating the main web or film, a reinforcing web, longitudinal sealing means for said webs, and brake mechanisms for the rolls;

Fig. 24 is a section at the line 24-24 on Fig. 23;

Fig. 25 is a fragmentary sectional view showing means for adjusting a roll of reinforcing film, including a pivot rod for a brake arm, the section being taken at the line 25-25 on Fig. 24;

Fig. 26 is a sectional elevation illustrating the sealing mechanism by which the main web is sealed longitudinally to form a tube, said section being taken at the line 26-26 on Fig. 1;

Fig. 27 is a section at the line 21-21 on Fig. 10 and shows the tube-forming mandrel;

Fig. 28 is a detail view showing particularly a shaping finger used in forming the longitudinal seam;

Fig. 29 is a fragmentary side elevation showing the rolls of reinforcing paper webs and means for assembling the webs with the tubular web, and also illustrates the tension and takeup mechanism;

Fig. 30 is a fragmentary cross-sectional elevation substantially at the line 30-30 on Fig. 1 and shows particularly the tension and takeup mechanism;

Fig. 31 is a cross-sectional elevation substantially at the line 3i-3i on Fig. 1, illustrating the cross-sealing mechanism;

Fig. 32 is a fragmentary side elevation showing the cross-sealing and'severing mechanism;

Fig. 33 is a fragmentary cross-sectional elevation substantially at the line 33-33 on Fig. 1, showing a pair of feed rolls and the bag severing mechanism;

Fig. 34 is a cross-sectional elevation showing the supplemental cross-sealing mechanism;

Fig. 35 is a part sectional side elevation of the same;

Fig. 36 is a section at the line 36-36 on Fig. 34;

Figs. 37 and 38 are sectional views at the lines 31-31 and 38-38 respectively on Fig. 35;

Fig. 39 is a fragmentary plan view of the sealing disk and heating element shown in Fig. 36;

Fig. 40 is a detail of the sealing means;

Fig. 41 is a plan view of a bag holding device cooperating with the sealing turret for holding the bag when the sealing head is withdrawn;

Fig. 42 is an end elevation of mechanism shown in Fig. 41;

Fig. 43 is a section at the line 43-43 on Fig. 41;

Fig. 44 is a detail view of a stop device shown in Fig. 41;

Fig. 45 is a fragmentary elevation view of mechanism for lifting the glue rolls and adjusting means therefor;

Fig, 46 is a plan view of mechanism shown in Fig. 45.

General arrangement and operation The machine as illustrated is designed to make bags from a series of strips or webs, The method of assembling these strips and forming the bags is illustrated diagrammatically in Figs. 1, 5 and 6 and may be generally stated as follows:

The main Web or strip of film I0 is fed from a supply roll II and as it advances is shaped to tubular form with its edges I2 overlapping. The edges are then sealed and the tube thus formed is thereafter collapsed with side portions thereof infolded, cross-sealed and severed transversely into individual bags. The web l0 forms the body or inner layer of the bag as shown in Fig. 9. Beneath the roll II is a pair of rolls I! of reinforcing strips I4. The web It! and reinforcing strips may consist of pliofllm or other thin, transparent, flexible material adapted to be sealed together by the application of heat and pressure.

The strips l0 and I4 are fed over a roll l5 and thereby brought into superposed relation with the reinforcing strips I4 suitably spaced apart and positioned to reinforce the portions of the web III which are later infolded and form opposite sides of the bags. The roll i5 forms a backing for sealing disks it which engage the marginal portions of the reinforcing strips, applying suillcient heat and pressure thereto to seal the strips to the main web. With one form of sealing disks herein shown the sealing takes place along narrow strips or seams. As a modified form of the invention the sealing area may be widened to the full width of the reinforcing strips.

The reinforced web is advanced over a guide roll I! and thence forward beneath a triangular shaping block or die l8. As the web advances the side portions thereof are folded upwardly and brought into overlapping relation as shown at l2, thereby giving the web a tubular form. A heat sealing roll l9 engages the overlapping edges of the web and seals them together. The tube thus formed advances along a mandrel 20 which forms a continuation of .the shaping block it. At the forward end of the mandrel there is provided means for infolding the reinforced sides of the tube and at the same time collapsing it to flattened form. Such means includes disks 2| by which the sides of the tubes are folded inwardly. The tube passes between a pair of feed rolls or pull rolls 22 and 23 by which it is fully collapsed.

Reinforcing strips or webs 24 and 25 supplied from rolls 24 and 25* respectively are fed forward into juxtaposition with the upper and lower sides respectively of the flattened tube. The web 24 as it is fed from the supply roll is directed over a backing roll 26 and is fed between the latter and a glue roll 21 running in a glue pot 28. From thence the web advances to a guide roll 29 over which the collapsed tube is also drawn. thereby adhesively applying the web 24 to the upper face of the collapsed tube. The lower paper web 25 is in like manner passed between a pair of rolls 3!! and 3], the latter running in a glue pot 32. The web 25 as it leaves the glue roll is brought into contact with and adhesively secured to the lower-surface of the tubular film as the latter passes over an idler roll 33.

The webs when thus assembled form the lammated or reinforced tube which in its collapsed form is advanced to a cross-sealing unit 34 by which the tube is heat sealed transversely at spaced intervals. As the portion of the tube which is being sealed is held stationary during this sealing operation, a tension and take-up mechanism is provided between the roll 29 and the sealing element 34 to take up the slack and provide for a continuous advance of the webs past the roll 29. Said tension and take-up mechanism includes a roll 35 and means for moving it up and down as hereinafter set forth and a guide roll 35.

After the sealing operation the tube is advanced to the cut-off .unit 36 which includes a pair of feed rolls 31, 38 and a knife 39 which periodically severs the tube at the cross-seals, thereby forming individual bags. A turret sealer 40 may be used for effecting a supplemental cross-sealing operation. This comprises a rotating turret 4| and clamping heads 42 which rotate therewith. Each bag B when severed by the knife 39 has its bottom end clamped between the turret 40 and one of the heads 42 for the final sealing operation. The bag-forming apparatus is mounted on a framework comprising horizontal channel bars 43 and 44 extending substantially the full iength of the machine.

Power drive and clutch mechanism The mechanism is driven by an electric motor 45 (F'g. I) mounted on the machine base and operating through speed reduction gearing within a gear box 46, a sprocket chain 41 and gear 48 to transmit motion to the main drive shaft 49 (see Figs. 14 and 20 to 22) which extends across the machine. The drive shaft has keyed thereto a bevel pinion 50 which drives a bevel gear mounted to rotate on a counter-shaft 52 which extends lengthwise of the machine.

Clutch mechanism for effecting a driving con nection between the gear 5| and the countershaft includes a clutch sleeve 53 slidable on the counter-shaft and carrying a pair of pins 54 which extend through a collar 55 keyed to the countershaft, said pins adapted to enter openings formed in the hub of the gear 5|. The clutch is operated by a hand lever 56 on a rock shaft 51 to which is keyed a yoke 58 engaging an annular recess in the sleeve 53.

The drive shaft 49, which rotates continuously while the motor is running, has driving connections independent of the counter-shaft 52 for driving the heat sealing rolls and the glue rolls while the counter-shaft and parts driven thereby are at rest. This permits the sealing rolls or disks to be uniformly heated prior to opera tion of the machine and prevents overheating of the backing rolls for the sealing disks While the machine is out of operation. It also permits the glue roll 21 and 3| which run in the glue pots to be continuously rotated which is necessary to keep the glue in proper condition.

The glue roll 2'! is positively driven from the shaft 49 by a sprocket chain 2! (Figs. 1, 14 and 15) running over sprocket wheels on the shaft 49 and the shaft of the roll 21. driven from the shaft 49 through a train of gearing including a sprocket chain 3 l which is trained over a sprocket wheel on the glue roll shaft and a sprocket wheel in a stub shaft 3| (Figs. 14 and 21). Intermeshing spur gears 3| and The roll 3| is 3| provide a driving connection between the shaft 3|" and the shaft 49.

Strip sealing units The driving connection between the shaft 49 and the longitudinal sealing rolls I6 includes a sprocket chain 59 (Figs. 1 and 14) driven from the shaft 49 and driving a shaft 60. The latter operates through a sprocket chain 6| and gear 6| (Figs. 1 and 24) to drive a shaft 62 (Figs. 1, 23 and 24). Sprocket chains 64 run over sprocket wheels 65 on the shaft 62 and sprocket wheels 66 on shafts 61. The latter have mounted thereon the pairs of heat sealing disks I6. Said disks are thus continuously rotated from the main drive shaft 49.

The heat sealing means includes two strip sealing units I6 and I6, each comprising a pair of disks I6 and a stationary heating element 68 for each pair of disks. Each heating element is electrically heated and the temperature thereof is automatically controlled by a thermostat 69. It will be noted that the sealing disks l6 are in close proximity to the heating body and are substantially enclosed, the heating element having a flattened face I0 to expose the sealing disks and permit them to contact with the web I4.

The sealing units II'i and I6 (Figs. 14, 15, 23, 24) are separately mounted in yokes I2 which are pivotally supported on a bearing sleeve I3 in which the driving shaft 62 for the sealing disks is journalled. Each unit includes a heating body 69 which is enclosed in a casing including side plates 14 having hubs in which the shaft 61 is journalled. said hubs being pressed into the arm of the yoke I2. The sleeve I3 is mounted in brackets I5 on the machine frame. The sealing units are separately adjustable lengthwise of the bearing sleeve I3. Means for adjusting the unit It includes an adjusting rod I6 (Figs. 23, 24), said rod being screw-threaded in a stationary supporting arm 11 on the machine frame. A yoke I8 mounted on the rod I6 includes an arm I9 through which the drive shaft 62 extends, said arm engaging between bearing lug on the yoke I2 for moving the sealing unit. A collar keyed to the shaft I6 provides an operating connection between said shaft and the yoke I8. Rotation of the shaft I6 by means of a knob I6 causes a lengthwise movement of the shaft and with it the yoke I8, th yoke I2 and the sealing unit I 6 An arm BI of the yoke I8 engages a recessed hub 82 of the gear 65 which is splined on the shaft 62, thereby adjusting said gear with the sealing unit. Adjusting mechanism for the sealing unit I6 substantially identical with that just described in connection with the unit I6 includes a screwthreaded adjusting rod 83 carrying a knob 83 and operatively connected to the sealing unit.

The guide ro-ll I5 over which the reinforced film is directed provides a backing for the sealing disks I6 and may consist of or be lined with rubber, rubber composition or other suitable backing material for the sealing disks. Means for holding the sealing disks with a yielding pressure against the roll I5 includes arms I04 fixed to or carried by the yokes 12, the latter being mounted to rock about the axis of the shaft 62. Coil springs I05 are connected each at one end to an arm I04. The opposite ends of the springs are connected to screw threaded rods I06 which extend freely through eyes in the ends of arms I01, the latter secured to the machine frame. Sleeves I08 threaded on the rods I06 hear at their inner ends against the arms I01 and carry adjusting knobs I09 at their outer ends. By rotating the knobs I09 the screw rods are moved lengthwise and thereby adjust the tension on the spring I03 and adjustably vary the pressure of the sealing disks against the films. A rod I I is connected to one of the arms I94 and is operable by mechanism as hereinafter described to swing the sealing units away from the roll l5. The sealing units are tied together for such swinaing movement by apin I I0 (Fig. 24) fixed to one yoke I2 and projecting into an opening in the opposite yoke.

Adjusting means and b rakes for film rolls The rolls I3 are separately adjustable laterally. The adjusting means for one roll includes an adjusting knob 94 (Figs. 23, 24 and on an adjusting shaft 95 having a screw-threaded mounting in an arm 86 on the machine frame. Journalled on the shaft 95 is a sleeve 91 held against movement lengthwise of the shaft by collars 33. An arm 89 extends from the sleeve 91 and at its forward end is formed with a shoe 90 which seats in a recess 9| (Figs. 15 and 23) in the spool on which the roll I3 is mounted. It will be seen that by rotating the knob 84 the shaft is adjusted lengthwise and operates through the parts just described to adjust the roll I3. The arm 99 also serves as a brake arm for adjusting and maintaining the tension on the web I4. The shoe 90 may carry a brake pad 92 of leather or the like. The braking pressure is applied by means of a weight 93 adjustable lengthwise on a rod 94 extending from the sleeve 91. Mechanism substantially like that just described is provided for adjusting the other roll I3 and regulating the tension of the web, including a knob 94, adjusting rod 94, brake arm 99*, rod 94 and weight 93.

The main film roll II (Figs. 14 and 23) is carried on a spool or tube 95 on a spool shaft 96. A brake mechanism for the spool serves to adjust the tension on the film. Said brake mechanism includes a'brake strap 91 engaging the spool and placed under tension by a bell crank lever 98 fulcrumed at 99 and carrying a weight I00 adjustable lengthwise of the lever for adjusting the tension on the brake strap. The spool carrying the film roll II is adjustable lengthwise 0n the shaft 96. The adjusting means includes a screw rod IOI screw threaded in the machine fram and a knob I02 for rotating the rod. An arm I03 is connected with said rod for movement therewith toward and from the machine frame. Said arm is connected with the spool shaft' 96 for moving the latter and the spool 95 therewith.

Forming the tube The web after passing the sealing rolls is directed over the idler roll I! and thence to the shaping means by which it is given tubular form. Such means includes the shaping block or mandrel I8 (see Figs. 5, 6, 10 and 11) and an entrance plate III therebeneath which is substantially triangular in shape and in effect forms a part of the mandrel. Th plate III engages and directs the sheet just before the commencement of and during its gradual formation or transi-- tion from a fiat sheet to tubular form. The plate slopes downwardly and forwardly and is placed at a predetermined angle to the horizontal center line of the mandrel required to prevent strains or stresses in the film at any point during the continuous forming operation. The calculated or theoretical angle holds good for a pertectly uniform, fiat and straight sheet of mm but adjustment to a slightly diirerent angle 'may be required when imperfect rolls of film are being and at its upper end carries screw rods II3 ad-' justable In brackets H4 and held in adjusted position by nuts H5.

As the web I0 advances along the shaping block I9, it is gradually given a tubular form, the edges I2 of the web being brought around the shaping block I9 and the mandrel 20 which forms a continuation thereof. The edges are overlapped about one-half inch, more "or less, before they reach the sealing disk I9. A pair of guide plates I I6 on opposite sides of the shaping block cooperate therewith to guide and fold the web around the block. A finger I I1 (Figs; 10, 27, 28) attached to one of the guide plates H6 serves as an additional guiding means and fiattens the overlapping edges of the film down onto the mandrel.

The mandrel I8, 20, is so shaped that the ad'- vancing film can closely follow the contour of the mandrel while being wrapped therearound to tubular form, without any portion of the film being placed under a stress or strain. To accomplish this, th shape of the mandrel is such that the length of each line measured along the surface of the mandrel and representing the path of any point in the film in its passage from the point at which the wrapping of the film commenses, to the point at the forward end of the mandrel at which the wrapping is completed, is equal to every other such line. the lines being measured from the point at which the folding operation commences to the point at which it is completed.

Seam sealer The seam sealer H9 in the form shown is similar in construction to and operates on the same principle as the sealing elements I6 and Iii heretofore described. Referring to Figs. 2 to 26, it comprises the sealing disk I9 mounted to rotate on a stud shaft I20 carried on a bracket I2I mounted to rock about'the axis of the shaft 60. The sealing disk is driven from the shaft 60 through a spur gear I22 (Fig. 14) on the shaft 60 and a spur gear I2'3 on the shaft I20. The gear I23 as shown in Fig. 26 is attached to the sealing disk by bolts I24.

Referring to Fig. 26 the seam sealing unit H9 includes a stationary heating element I31 electrically heated, the temperature being controlled automatically by a thermostat. The roll or disk l9 and heater body I31 may be enclosed in a casing I38, if desired, and an outer housing I39 of heat insulating material may be provided. Beneath the sealingdisk I9 is a backing roll I40 of rubber or other resilient material. The roll I40 is mounted in the mandrel 20. 'Shields or guides I4I, adjustably mounted on posts I42, ex tend over the upper part of the mandrel adjacent the sealing disk and guide the film as it approaches the sealing disk. The mandrel is provided with a longitudinal recess I43 (Fig. 10) extending forward from the sealing disk to hold the film out of contact with the mandrel along the heated seam and thereby prevent sticking.

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