US2649671A - Method of and machine for packaging material in an inert gaseous atmosphere - Google Patents

Description

7 Sheets-Sheet 1 Aug. 25, 1953 H. L. BARTELT METHOD OF AND MACHINE FOR PACKAGING MATERIAL IN AN INERT GASEOUS ATMOSPHERE Filed Dec. 10, 1949 Y H 1 x M e o LIP 1 1 NN o m m 2 T M m I @Q a d mm v I d N Q FN u v aw 9o q MW mm.. mm mu a. q HH HI W HHHHIHNU HHHMH l A m '@N A fnov W mmw L i a 8 m \f mm fix m \1 g F, IIL mm wk .I. r .v N .n W m: m an. I

on 0m 8. E

Aug. 25, 1953 H BARTELT 2,649,671

METHOD OF AND MACHINE FOR PACKAGING MATERIAL IN AN INERT GASEOUS ATMOSPHERE Filed Dec. 10, 1949 7 Sheets-Sheet 2 1953 H. L. BARTELT 2,649,671

METHOD OF AND MACHINE FOR PACKAGING MATERIAL IN AN INERT GASEOUS ATMOSPHERE Filed Dec. 10, 1949 7 Sheets-Sheet 3 TOMEJV 1 Aug. 25, 1953 H. BARTELT 2,649,671

METHOD OF AND MACHINE FOR PACKAGING MATERIAL IN AN INERT GASEOUS ATMOSPHERE Filed Dec. 10, 1949 T Sheets=Sheet 4 ENVE'NTO mcw'olci L. @ow'fe It Aug. 25, 1953 H. L. BARTELT 2,649,671

METHOD OF AND MACHINE FOR PACKAGING MATERIAL v IN AN INERT GASEOUS ATMOSPHERE Filed Dec. 10, 1949 7 Sheets-Sheet e Patented Aug. 25, 1953 UNITE METHOD OF AND MACHINE FOR PACKAG- ING MATERIAL IN AN INERT GASEOUS ATMOSPHERE Harold L. Bartelt, Rockford, Ill., assignor of fortyfive per cent to Donald E. Bartelt Application December 10, 1949, Serial No. 132,378

21 Claims.

This. invention relates to a method of and machine for packaging material in fiexible walled bags filled with an inert or nonoxidizing gas. The invention has more particular reference to the filling and closing of bags which are formed from continuous strips of material advanced endwise through a line of stations at which the various forming and filling and closing operations are performed.

One object is to provide a packaging method and machine of the above character in which the nonoxidizing atmosphere is introduced into the bags in a novel manner such as to eliminate air from the final package.

A more detailed object is to advance the bags with the walls thereof collapsed and the bags thus freed from air into an inert or nonoxidizing gaseous atmosphere and thereafter opening the bag preparatory to fillingthereof whereby to utilize the vacuum created by the separation of the bag walls to draw the surrounding gas into the bag and completely fill the latter.

A further object is to adapt the foregoing method to a bag forming and filling process of the continuous type.

Another object is to confine the inert or nonoxidizing gas within a chamber enclosing only packaging machine embodying the novel fea-' tures of the present invention.

Fig. 2 is a fragmentary longitudinal elevational View of the right-hand portion of the machine shown in Fig. 1 with some of the parts shown in section. I

Fig. 3 is a diagrammatic perspective view showing the various bag forming, filling, and closing steps.

Fig. 4 is a sectional view of a filled bag.

Fig. 5 is a fragmentary sectional view taken along the line 55 of Fig. 1.

Fig. 6 is a fragmentary sectional View taken along the line 6-6 of Fig. 5.

Fig. 7 is a fragmentary sectional View taken along the line 7-4 of Fig. .2. s

Fig. 8 is a fragmentary sectional view taken along the line 8--8 of Fig. 2. I

Fig. 9 is a fragmentary sectional view taken along the line 9-9 of Fig. 8.

Fig. 10 is a fragmentary sectional view taken along the line lD-ID of Fig. 2.

Fig. 11 is an enlargement of a part of Fig. 10 showing the parts in different positions.

Fig. 12 is a fragmentary sectional view taken along the line l2 l2 of Fig. 2.

Fig. 13 is a fragmentary view showing a modified form of outlet valve.

The invention is useful for automatically packaging a wide variety of materials subject to deterioration in air including nuts, sauerkraut, pickles, prunes,'wieners, cold meats, etc. While the invention is susceptible of various modifications and alternative constructions and may be practiced in various ways, I have illustrated in the drawings and will herein describe the preferred embodiment and manner of carrying out the invention. not thereby intend to limit the invention by such disclosure but aim to cover all modifications, alternative constructions, and methods falling within the spirit and scope of the invention as expressed in the appended claims.

As illustrated in the drawingsthe invention is particularly useful in packaging loose or granular material M such for example as nuts in a protective gaseous atmosphere retained around the nuts by a bag I5 (Fig. 4) comprising .two flexible coextensive walls l6 of transparent sheet material closed at the bottom as by a fold and sealed as indicated at I! and I8 along the side and top edges. preferably is thermoplastic or thermoplastic coated, must be impervious to and unaffected by the protective or nonoxidizing gas which may be nitrogen, carbon dioxide, or the like.

Packages of theabove character may be formed cheaply in a succession of operations .performed on strip material followed by filling and closing automatically in a continuation of the bag forming process. Such a process may, as shown,

- consist in folding asheet 19 of the wall material as the latter is advanced step by step along a rectilinear path, cross-sealing at a station 20 the two strips 2| thus disposed face to face, severing the cross-seal intermediate its edges at a cutting" station 22 thereby completing theformation of the bag, opening and filling the bag at a It is to be understood that I do.

The Wall material, whichgas, and filled with the protective gas automat ically as an incident to opening of the bag preparatory to filling thereof with the nuts orother material to be packaged. Thus, ,the opening of the bag which is performed as an. incident to depositing the material in the bag is utilized to perform the additional function of introducing the protective gas into the bagso' asto envelopthe packaged material and eliminate air and oxygen from the package which is completed by the subsequent sealing of the open end of the bag.

The improved method as above described is carried out simply by providinga. casing r housing 25 enclosing the filling and closing stations 23- and 24 and. supplying. the nitrogen or other nonoxidizing gas to the chamber 26 thus defined so as to maintain the latter under pressure at all times and thus exclude air from the space surrounding the bag at the time it is opened preparatory to introducing the material to be packaged and continuing until. the filled bag has been closed by forming the top seal l8. As a result of advancing the bag into the gas chamber while the walls thereof are flattened or collapsed together, the vacuum created in the bagby separating the walls is utilized to advantage to draw the gas into the bag and thus fill the latter completely before introduction of the material to be packaged.

In addition to preventing air from entering or being trapped in the final package, the invention also contemplates that the material to be packaged and the power actuators for the various bag forming, filling, and closing mechanisms remain outside of the gas filled enclosure and therefore conveniently accessible for replenishment, adjustment, or repair. These mechanisms together withthe casing 25 defining the gas chamber 26 and the conveyor for advancing the bag stock and bags from station to station are all mounted on a; frame structure comprising-side members 2'! rigidly connected by crossbars' 28 and having parallel top rails 29- and upright supporting legs 30.

In this instance, the casing 25 defining th gas chamber 26 is generally rectangular in shape and comprises a top wall 3| formed integral with side walls 32 and having openings for the passage therethrough of the nonoxidizing gas and the material to be packaged, a bottom wall formed by spaced cross members and overlapping sheets 34 of metal secured to and spanning the top rails 29 of the frame, and end walls 35 and 36,0ne of which has an inlet opening 31 therein for the advance of the collapsed bags into the chamber. The top, side, and endwalls ofthe casing are formed of sheet material, the side walls being secured as by screws to the frame top rails and the end walls being secured by brackets 38 to the side, top, and bottom walls. Holes formed in the cross members of the bottom wall receive the connections between the bag forming, filling, and closing mechanisms disposed within the chamber and the power actuators for these mechanisms which actuators are disposed outside of the cas- 4 ing. A door 4| hinged as at 42 to the top wall and forming a part of one side wall permits entrance to the interior of the casing for adjustment of the mechanisms therein.

Actuation of the various bag forming, filling, and closing mechanisms is effected in this instance by a camshaft 43 extending along the frame below the top rails and jo-urnaled in spaced bearings 44. This shaft is driven through a; belt 45 from an electric motor 46 (Fig. 1) and a speed reducer 4!- of well known construction adapted to be adjusted manually to vary the speed of the shaftand therefore the output capacity of the machine.

Introduction of the nonoxidizing gas into the chamber 26 is effected herein by a tube 48 extending through the top wall 3| of the casing 25 adjacent the filling station 23 and communicating with a storage tank 49 for the gas through a supply line 50 and a valve 5|. The gas is maintained' under a slight pressure within the chamber on the order of a few ounces above atmospheric pressure, the amount of gas fiowing into the chamber being determined herein by manual adjustment of the valve 5 I.

To minimize the loss of the nonoxidizing gas from the chamber 26 through the inlet opening 37, the invention contemplates forming the opening as a slit wide enough to receive the bags only when the latter are flattened or, collapsed and moving edgewise through the opening. Advance of the bags alone without any bag feeding mechanism passing through the opening is permitted by locating the cutting station 22' within the chamber and thereby delaying severance of the bags from the strips 2| up to a point within the chamber so that the bags, during their advance into the latter, remain interconnected in a continuous ribbon. With the bags so interconnected, they may be easily pulled into the chamber by feeding mechanism located on the inner side of the end wall 35.

By' pulling the strips 2| of the bag material through the inlet opening 3'1, it is. possible to space the defining edges ofthewopening sumciently close together to press tightly against the outer sides of the strips so that air is squeezed from between the latter as they advance into the chamber and thereby prevented from being trapped in the final package. In this instance, the opening (Figs. 5 and 6)- is defined by adjacent parallel edges of two flaps 52 of flexible material such as leather extendin across a hole 53 in a plate 5d and secured to the latter as by rivets. To change the size of the slit readily for bags of varying heights and thicknesses, the plate is detachably mounted the end wall 35 over a hole 55 therein as by guides 56 which are securedto the wall and slidably receive the plate.

In the present instance, the feeding mechanism for advancing'the strips 2| endwise into the chamber through the inlet opening 3'? comprises two rollers 51 andv 58 (Figs. 2 and 3) which are driven intermittently from the camshaft 3 and are engageable with the outer sides of the strips 2| at a point adjacent the inner side of the end wall 35. One roller 51 is fast on a shaft 59 extending through the bottom wall of the casing and mounted in medbearings on a bracket 60 (see Figs. 1 and 2) on a cross member 33 forming a part of the bottom wall. The other roller 53 is carried by a yoke 6| which is pivoted on the bracket 66' and adjustable toward and away from the fixed roller to produce the pressure required to advance the folded strip without substantial slippage. At their lower ends the rollers carry meshing gears 62 and a bevel gear fast on the shaft of the fixed roller meshes with a gear 63 (Fig. 3) on a shaft :65 which is coupled through a one-way clutch 65, such as a so-called Sprag clutch, to an arm 6-5 loosely mounted at one end on the shaft 64 (Figs. 1 and 3). The bevel gears are enclosed in a housing 84 depending from the cross member 33. The other end of the arm 66 is joined by a link 61 to the pin 68 of a crank 69 fast on the camshaft 43. During each revolution of the latter, the rollers are turned to advance the strips a predetermined distance determined by the position of the pin along the crank.

To form the strips 2!, the continuous sheet IQ of bag material is unwound by the feed rollers 51 and 58 from a roll 79 and'advanced through a mechanism H by which the sheet is folded longitudinally. The roll it is mounted on a shaft journaled at opposite ends in supports 12 disposed outside of the casing and secured to the frame at one end of the latter.

From the folding mechanism ll, the strips 2! are advanced through the cross-sealing station 20 which is located adjacent the outer side of the end wall 35. Such location of the crosssealing station renders the sealing mechanism convenient for adjustment and repair andenables the casing 25 to be made smaller so as to reduce the consumption of the nonoxidizing gas. To effect cross-sealing of the strips, a shoe l3 heated to a temperature sufficiently high to soften the thermosensitive bag material is secured to the upper end of a vertically'disposed lever TE- which is pivoted intermediate its ends on a cross member E5 on the frame and carries at its lower end a follower roller 16 engageable with a cam H on the camshaft 33. Whenthe follower roller engages a rise surface on the cam, which occurs during adwell of the strips, the heated shoe is swung against the stripsand pushes the same against a yieldable backing surface 18 supported on the cross member, the areas of the strips pressed between'the shoe and the backing being sealed together under the resulting heat and pressure.

Severance of the strips 2 I' after the latter have beenadv'anced into the chamber 25 is effected herein by two vertically disposed blades 3%} and 8! which are located at the cutting station 22 between the filling station 23 and the feed rollers 57! and 53. One of the blades is mounted on one side of the strips on a standard 82 projecting upwardly from the cross member 33 supporting the bracket 6i] for the feed rollers 5'6 and 58. The other blade 8! is mounted on theupper. end of an upright lever 83 which extends through a hole 63 in the cross members 33 and is fast on arock shaft 85 journaled inthe plane of the strips 0 the housing 84 for the bevel gear 63. At itslower end, the lever 83 carries a follower roller 86 engageable with a cam 8'! on the camshaft 43 and swingable thereby during a dwell of thestrips to carry the moving blade edge across the stationary edge and sever the strips along a sealed portion thereof. By positioning the blades from the heated shoe at the sealing station 29 a distance equal toa multiple of the distance the strips are advanced during each revolution of the camshaft, the center of a sealed portion of the strips is positioned in the path of the swinging blade Bl during each dwell of the strips. 'When the folpieces.

lower 86 is engaging the low part of the cam, the blade BI is retracted and the strips may be advanced between the blades. I

In each advance of the folded strip, the leading end portion thereof is moved past the cut-off position and onto a conveyor (see Figs. 7, 8, 9 and 10) which grips the bag prior to cut-off and advances the same step by step to the filling and closingstations 23 and 24. Hereimthe conveyor comprises an endless chain 89 of the roller type extending around sprockets 90 and Si and having spaced uniformly therealong gripping devices 92 which are closed and opened automatically and carry the bag along a horizontal track formed by a bar 93' (Figs. 8 and 11) and supporting the bottom of the bag above'the frame cross- The chain and the sprockets therefor are disposed in a horizontal plane above the frame rails 29 with onerun of the chain extendin alongside the line of advance of the bags.- A

bearing 94 (Fig. 9) on the frame supports one sprocket 90 while the other sprocket 9i which drives the chain is fast on a shaft 95 journaled in a bearing (Fig. 12) supported by a cross member I04 on the frame.

Advance of the chain step by step is effected herein by a crank 96 (Figs. 1 and 2) fixed on the far end of the camshaft 43 and connected to one end of a rod 9? Whose other end carries a pawl 98 which is held by a spring in engagement with the teeth of a ratchet wheel 99 (Fig. 12). The latter is fast on a shaft connected to the shaft 95 of thesprocket 9! through bevel gears illil. Durmg each upward'movement of the rod 97, the chain and all of the gripping devices 92thereon will be moved through a fixed distance which preferably is longer than the width of the widest bag to enable the conveyor to handle all of the bag sizes without changing its stroke. The crank 96 is so positioned on the camshaft that the chain will be indexed while the strips 2! at the cross-sealing and cutting stations 2!! and 22 are stationary and immediately after the blade 8! has been advanced to sever the strip. The conveyor motion is completed before the blade-is retracted and the subsequent feeding of the folded strip is initiated.

The gripping device 92 each comprise a block 2 (Fig. 8) secured toextensions of the pivot pins of adjacent chain links and disposed at the side of the chain with the exposed surface of the block disposed close to the path of advance :of the strips 2i1 -Cooperatingwith the block surface to forma clamp is a jaw lill (Figs. 8, 9, and I2) pivoted on the block to permit the trailing end of the jaw to rock away from thelatter; The

'trailing end of the jaw" is yieldably urged by a spring toward arclosed position ag'ainstthe block surface and is bent outwardly to cooperate with the beveled trailing end-of the block to guide the entry of the leading end of the folded strip into the gripping device. a

To open the clamp, the leading end portion I82 of the jaw In! is inclined outwardly and away from the block 92 for engagement by a finger :93 (Figs. 8 and 9) on the upper end portion of a lever I05 which extends through a hole 106 in a disposed at the cutting station thereby rocking the trailing end of the jaw outwardly and holding the gripping device open. When the blade 8-I is advanced, the lever I135 is swung with the cut-off lever to retract the finger I03 and .allow the jaw to close. Thus, the leading end of the bag bottom is clamped to the chain for movement with the latter to the. filling station.

Each bag I 5, after it has been severed from the folded strip and while it is supported by the chain 89., is advanced in a collapsed condition to the filling station 23 where the side walls I6 of the bag are engaged adjacent the open end thereof and separated to open the bag and draw the .nonoxidizing gas into the latter preparatory to the delivery of the material into the bag. In the present instance, the side walls I6 are separated to open the bag through the use of suction cups .I II (Figs. 8 and 11) which are moved against the outer surfaces of the walls adjacent the open end thereof, subjected to a vacuum, and then moved outwardly all in timed relation to the indexing movements of the chain and the operation of the associated filling mechanism. The cups which are made of soft rubber material are mounted on the ends of horizontally disposed tubes I I2 rigid with the upper ends of upstanding arms N3 of bell crank levers I I4 disposed on opposite sides of the bag at the filling station 23 and swingable about a common pivot on the cross member I01. Swinging of the bell cranks is effected through links .I I5 connecting the outer ends of the cranks with aslide H3 urged downwardly by a spring Ill and guided for vertical movement in a bracket H8. The latter depends from the cross member I01 (Fig. 2) which is formed with a hole H9 therein to receive the bell cranks. On the lower end of the slide .is the follower I20 of a cam I2I fast on the camshaft 43 and adapted to raise the slide as shown in Fig. 10 and thereby swing the cups into alinement with each other and against opposite side walls of the bag then disposed at the filling station. As the follower rides off the high point of the cam, the bell cranks swing outwardly to the positions shown in Fig. 11 thereby separating the upper end portions of the bag walls.

Before such separation of the cups III occurs, a vacuum is created therein by the action of a pump I22 (Figs. 1 and 2) which is actuated from the camshaft 43 and comprises a cylinder I 23 mounted on the machine frame and communicating at its upper end with flexible conduits I24 extending through sealed apertures in the cross member 101 and connected to the tubes II 2 leading to the suction cups. A piston I25 reciproca- .ble in thecylinder has a rod connected by a link 1.26 to the free end of a crank I27 which is posit-ioned on the camshaft to initiate downward movement of the piston and the application of a vacuum to the suction cups as soon as the latter are brought against the bag walls I-E. The vac- "uum continues for the remainder of a half revolution of the camshaft-during which the cups are separated to open the bag and the latter is filled. As the crank motion reverses, which occurs while the cups are held apart, the vacuum is relieved and the bag walls released to permit the bag to be pulled forwardly in the next advance of the conveyor. The degree of vacuum may be varied by adjusting a valve I28on the pump (Fig. 2).

As noted above, the material to be packaged is. stored outside of the casing 25, herein in a cone-shaped hopper I29 (Figs. 1 and 10) mounted on a measuring mechanism I3 I (Figs. 1 0 and ill) and having a bottom opening I30 communicating through the measuring mechanism with the top of a filler tube I32. The latter extends vertically through the top wall 3| of the casing so that the material falls by gravity through the tube into bags at the filling station while the walls of the bags are separated. The measuring mechanism is mounted on a support I33 secured to the frame and comprises a circular disk I34 fixed to a vertical shaft I35 for rotation between two spaced parallel plates I36 and I31. Spaced angularly around the disk are a plurality of holes I38 which extend axially therethrough. A hole I39 in the lower plate I3! is alined with the filler tube I32 while a hole I40 in the upper plate I36 is alined with the opening in the hopper bottom. Both plates together with a side wall I4I cooperate to form a casing around the disk, the upper plate being spaced slightly above thetop surface of the disk.

When one of the holes I38 in the disk is alined axially with the hop-per opening I30 and the hole I40 in the upper plate, a quantity of the material I4 determined by the size of the hole I38 and the thickness of the disk falls by gravity into the hole. Upon rotation of the disk, each quantity of material in a disk hole thus filled is first carried around the axis of rotation of the disk between the plates and then, when the hole is alined with the filler tube I32 and the hole I39 in the lower plate, falls by gravity down through the tube and into a bag being held open under the latter. Scrapers in the form of stiff brushes I42 secured to the upper plate I36 may be positioned around the periphery of the hole I40 therein to maintain the level of material in the disk hole I38 fiush with the upper face of the disk. By turning the disk in the proper timed relation to the motion of the camshaft 43, a measured quantity of the material falls from one of the holes I38 in the disk through thetube I32 atthe same time that a bag is 'being held open by the suction cups I II.

While the disk 134 may be turned by'a connection with the camshaft .43, it is preferred to use a motor I43 which, when started, goes through a cycle to present an empty one of the holes I38 in the .disk under the hopper I29 and a filled one of the holes in. axial .alinement with the filler tube I32 and then stops. Herein, the motor (see Fig. 10) is mounted on the support I33 and connected to the shaft I35 of the disk through gearing I44. Starting of the motor in its cycle in the proper timed relation to separation .of the bag walls is effected by a switch I45 (Figs. 1 and 2) mounted on one of the cross bars the switch .as the bag at the filling station is opened. When the switch is actuated the motor turns the disk through a predetermined angle depending on the number of holes in the disk I34 to present a filled hole in alinement with the filler tube and thenstops until the switch is actuated again when the next bag is opened.

After passing the filling 'station 23, each bag I5 is moved along with the chain 89 into the closing station 24 at which the bag is heat sealed across the top to effect final closure of the bag. This is accomplished by mechanism which is similar to that for cross-sealing the strips 2I at the station 20 and comprises a backing block I41 (Figs. 2 and 7) and a heated block I48 between which the upper edge of the bag is pressed momentarily. The block I48 .inwhich a suitable electric heater is embedded is fixed to the upper end of an upright lever I49 swingable about a pivot I50 on a cross member II on the rails 29 and extending through a hole I52 therein. At its lower end the lever I49 carries a follower I53 ridinga cam I54 which is fast on the camshaft 43 and shaped to 'hold the heater retracted during the advance of a bag into the sealing station and to advance the block I43 to press the top of the bag against the backing I41. momentarily during a dwell of the latter to effect sealing across the entire Width of the bag.

The holes 46, I06, H6, and I52 in the cross members 33, I01, and I5! through which the actuating levers for the various mechanisms at the cutting, filling, and closing stations 22, 23, and 24 pass are sealed to prevent the loss of the nonoxidizing gas from the chamber 26 While permitting relative movement between the actuating levers and the cross members. For this purpose, a flexible seal or diaphragm I56 (Figs. 2, 8, and 11) is interposed between each lever and the cross member through which the latter extends. Each seal which herein is molded from rubber or other flexible material. corresponds in shape to the hole closed thereby and is formed with ahole I 57 for each lever extending through the seal and a flange I58 adapted to be clamped to the cross member as by a metal ring I59 and screws I60.

The invention contemplates removing filled and sealed bags from the chamber 26 with a minimum loss of gas therefrom by momentarily opening a wall of the chamber and moving a bag out of the chamber-through the opened wall. For this purpose, the bags are released from the chain-89' within the chamber above a receptacle I III in the form of a vertically disposed tube which catches each bag as it is released from the conveyor and extends through the cross member I64 of the casing at a discharge station I62 beyond the closing station 24 to define an outlet opening I63 in the bottom wall. Normally closing the open bottom end of the receptacle is a trap door or gate I64 which is moved to an open position automatically in timed relation to advance of the conveyor to permit removal of the bags and then closed. Such a momentary opening of the chamber is permitted by releasing the bags from the conveyor within the chamber so that the conveyor remains at all times enclosed within the casing and does not pass through the outlet opening I63. An inclined chute I65 is disposed outside of the casing under the bottom end of the receptacle to receive the bags as they are discharged from the chamber and transfer the same to a suitable container (notshown) Release of the filled and sealed bags from the chain 89 so that the bags may fall into the receptacle I6 I is effected herein by a stationary cam I 66 (Figs. '7 and 12) which is disposed in the path of the curved portions I02 of the jaws I6I of the gripping devices and is carried by a bar I6? secured as by bolts to a wall of the receptacle. As a gripping device with a bag clamped therein as shown in Fig. 2 reaches-the cam, the latter acts in the leading end of the jaw WI and wedges this end laterally of the path of travel toward the chain to open the gripping device and release the baggso that the latter falls into the receptacle. Herein, release of the bag occurs just before each advance of the conveyor is completed.

The trap door I 64 is in the form of a plate pivoted on the lower end of the receptacle I6I 16 to swing from a position in which the receptacle is open and bags may fall. onto the chute I65 to a closed position in which the receptacle is closed (see Fig. 12). In the form shown in Fig. 12, the door is urged into closed position by a spring I68 and opened as an incident to advance of the chain39. Such opening is effected herein by pins.

I69 projecting from the ratchet wheel 99 and engageable with a finger I10 which projects from the door and is cammed by the pins in a direction to open the door. The pins are so positioned on the ratchet wheel that the door is opened to release each bag thereon at the beginning of each advance of the chain, the bag having been released from the latter at the end of the next preceding advance thereof; By providing short fingers I'Ill, the door is held open only momentarily. I

In a modified form of means for actuating the trap door I64 shown in Fig. 13, the door is held balanced in a closed position by a counterweight III carried on an arm I12 projecting from the door across the pivot therefor. By making the counterweight slightly heavier than the door but lighter than the combined weight of a filled bag and the door, the latter is opened automatically each time a bag hits the door after being released from the conveyor, the weight of the door and bag overbalancing that of the counterweight III. After the bag slides onto the chute and pit from the door, the latter again swings to a closed position. With the use of a counterweight, the trap door is opened in timed relation to release a bag from the conveyor, is held open for a short period of time in which the bag falls by gravity from the chamber, and is then'closed automatically.

The various mechanisms above described are typical of those which might be used to convert a continuously moving sheet or strip of ma-- terial into bags, fill the bags, and then close the same. By actuating the mechanisms in timed relation and from a single camshaft it is possible during each revolution of the latter to complete an automatic cycle in which eachmechanism is actuated once.

As the camshaft 63 is turned by the motor 46 through one revolution, a lengthof the sheet I6 of bag material is pulled by the feed rollers 57 and 53 from the roll III and through the folding mechanism II to form the two strips 2I which are advancedbetween the separated shoe I3 and backingsurface-IB at the sealing. station, are slid into the chamber 26 between the,

flaps 52 which squeeze air from between the strips, and are advanced between the separated blades 8E! and BI at the cutting station with the leading ends of the strips advancing into an open gripping device on the chain 89. During a dwell of the strips following such advance, the

heated shoe I3 is moved toward the backing surface I6 to seal the strips together and the blades 66 and, 8! are moved together to sever a bag from the strips:

Immediately before a bag is' severed from the. strips 2! the gripping device is closed toclamp the leading end of the bag and the chain 89 is advanced through one step to position an empty bag between the suction cups III at the filling station 23, a filled bag M8 between" the separated shoeandbackingsurface I I! at the closing station E i, and a filled and sealed bag at the discharge station I62. In such movement of the chain, the filled, and sealed bag presented at the discharge stationin the previous advance of the chain is released from the latter to fall into the receptacle ifil. After the released bag has fallen on to the trap door I64, the latter is automatically opened momentarily to permit the bag to slide onto the chute I65 and then closed.

During a dwell of the chain, the heated shoe H38 is advanced to close the filled bag at the closing station by sealing the walls thereof together at the top'and the suction cups III are advanced and retracted to open the collapsed and empty bag at the filling station 23. While the bag is held open, the switch I45 is actuated to start the motor 143 and turn the disk I3 3 to deposit a measured quantity of the material [A into the filler tube' I32 from which the material falls into the bag. Since the filling station is surrounded by the nonoxidizing gas, the bag upon separation of the walls thereof is filled with the gas to provide a protecting atmosphere for the material deposited in the bag.

It will be apparent that the location Of the cross-sealing station 20, the camshaft $3, the hopper I 29, and the measuring mechanisml3! alloutside of the casing 25 and the chain 89 entirely within the latter makes it possible to provide a small chamber having few openings in the'walls thereof with the result that the amount of the nonoxidizing gas consumed is' very low. Also, the parts outside of the chamber are conveniently accessible for replenishment, adjustment, and repair. The loss of gas from the openings in the casing is minimized because the discharge outlet 163 is opened only momentarily to release the completed bag and because a close scaling is effected at the inlet opening 3'1. By advancing the bags into the chamber while their walls are collapsed together and by closing the bags while the latter are in the nonoxidizing atmosphere, there is little possibility of air being trapped in the filled and sealed bags. During delivery of the material l4 into the opened bag, some of the protective gas escapes from the chamber 23 upwardly through the tube l32 past the downwardly moving material. The danger of air being carried into the bag with the material is thus reduced to a minimum.

I claim as my invention:

1. In a packaging machine, the combination of, a casing defining a chamber having a slit in one wall thereof, means for introducing a nonoxidizing gas into said chamber and maintaining the same under pressure therein, mechanism for supporting two strips of flexible material side by side and advancing the same periodically in successive steps endwise along a path extending through said slit and into said chamber, sealing elements disposed outside of said chamber and operable to cross-seal said strips to form pockets opening upwardly at one end, a cutter disposed within said chamber and operable during a dwell of said strips to sever the latter along the cross-sealed portions thereof and divide said pockets into separate bags, grippers within said chamber engageable with each bag, a conveyor mounting said grippers and movable to advance said bags beyond said path, a bag'opener disposed within said chamber for engagement with the walls of each bag adjacent the open end thereof and operable to separate the walls and create a vacuum in the bag for drawing the gas into the same through said open end, a filler operable to deliver a measured quantity of material through a wall of said chamber into said bag while the latter is held open, and sealing elements within said chamber engageable with the filled bag and operable 12 to seal the walls of the bag across said open.

end.

2. In a packaging machine, the combination of, a support for two strips of flexible material disposed side by side and lying flat against each other, feed mechanism 'engageable withsaid strips and operable to advance the same endwise, heat sealing mechanism engageable with said strips and operable to seal the same .together at points spaced along the strips and form intervening pockets open at one end, cutting mechanism engageable with said strips along the sealed portions thereof and operable to sever the same and form separate bags, bag open-- ing mechanism engageable with the walls of each bag and operable to move the walls apart to open the bag, closing mechanism operable to seal the walls'of each bag together across the open end thereof, a casing having an inlet opening in one end wall for the passageioft said strips therethrough and enclosing a plurality of said mechanisms including said cutting, said bag opening, and said closing mecha- I nisms, said sealing mechanism being disposed outside of said casing, means for introducing an inert gas into said casing and maintaining the same under pressure therein, and a filler tube extending through 'a wall of said casing for delivering a measured quantity of material to be packaged into said open bag.

3. In a packaging machine, the combination of, a casing defining a chamber and having a slit in one wall thereof, means for introducing non-oxidizing gas into said chamber and maintaining the same underpressure therein, mechanism disposed outside of saidchamber for partially forming fromtwo strips of flexible mate rial a bag having an opening in one end and two side walls disposed side by side and lying fiat against each other, feeding elements engageable with said strips and operable to advance the same endwise through said slit and into said chamber, the edges of said slit being defined by flexible members yieldably engaging said strips, mechanism disposed within said chamber for completing the formation of said bag and severing the same from said strips, a bag opener within said chamber engageable with the outer surfaces of said bag and operable to move the walls thereof apart and thereafter release the walls, a filler operable while the bag walls are held apart to deliver material through a wall of said casing into said bag, sealing elements within said chamber'for sealing the walls of the filled bag across the open end thereof, and means for removing the filled and sealed bag from said chamber.

4. In a packaging machine, the combination of,- a casing, means for maintainingsaid casin filled with a gas of predetermined composition under-pressure, mechanism for holding a flexible walled bag collapsed and'supported within said casing, said bag. having ano-pening in one end thereof, bag opening meanswithinsaidcasing acting on the walls of said bag and movable to separate the walls to create a vacuum in the bag and draw said gas into the bag through the opening therein, mechanism for delivering a measured quantity of material through a wall of said chamher and into the open bag, and sealing elements within said chamber engageable with the filled bag and operable to seal the Walls of the bag together across the open end thereof.

7 5;. In apackaging machine, the combination of, means defining a chambenmeans for maintaining said chamber filled with a non-oxidizing gas under pressure, mechanism for supporting within said chamber a collapsed flexible walled bag having an opening at one end thereof, a pair of elements disposed within said chamber and adapted to grip the outer surfaces of said bag, mechanism disposed outside of said chamber and operable to move said elements relative to each other to bring them into gripping engagement with the walls of the bag and then separate the elements to move the walls apart and create a vacuum in the bag to draw the gas through said opening and into the bag, and means for transmitting motion to said elements tooperate the same including connections extending through a wall of said chamber and sealed insaid wall.

6. In a packaging machine, the combination of, means for supporting a pair of strips of flexible material side by side and advancing the same through cross-sealing, cutoff, filling, and closing stations, a casing enclosing said cut-oil, filling, and closing stations and having an opening in one end wall thereof for the passage of said strips therethrough, said cross-sealing station being disposed outside of said casing adjacent said end wall, means for introducing a nonoxidizing gas into said casing, mechanisms at said stations operable on said strips to form, fill, and close separate flexible walled bags, power driven means disposed outside of said casing and operable to actuate said mechanisms in timed relation to each other, and actuating elements connecting said power driven means and said mechanisms.

'7. In a packaging machine, the combination of, a casing, means for maintaining said casing filled with a non-oxidizing gas under pressure,

14 9. The method of ackaging material in a flexible walled bag including the steps of, maintaining an inert gas underpressure in a chamher having a slit in one end wall and an outletopening in another. wall of the chamber at the other end thereof, partially forming outside of said chamber a bag having an opening in one end and flexible side walls lying fiat against each other, advancing said flattened partially formed bag edgewise into said chamber through said slit, separating the walls of said bag within said chamber to create a vacuum within the bag and draw the gas into the bag through said bag opening, delivering material to be packaged into strips of flexible material endwise through said mechanism for holding an upwardly opening flexible walled bag collapsed and supported within said casing, means within said casing engageable'with said bag and movable to separate the walls thereof to create a vacuum in the bag and draw said gas into the bag through the bag opening, a hopper disposed outside of said casing and adapted .to receive material to be packaged, a filler tube extending through an opening in one wall of said casing and having an aperture therein disposed above the open end of said bag, filling mechanism communicating with said tube and said hopper and operable to deliver measured quantities of material into said tube for delivery into the open bag, and means engageable with the filled bag within said chamber to seal the bag across its open end.

8. The method of packaging material in a flexible walled bag including the steps of, maintaining a gas of predetermined composition under pressure in a housing having a slit in one end wall thereof, advancing a pair of strips of flexible material endwise and step by step into said housing through said slit with adjacent sides of the strips lying in contact with each other and joined along one of their longitudinal margins, cross-sealing said strips together at spaced points to form pockets having top openings, severing said strips within said housing along the crosssealed portions of the strips .to divide said pockets into separate upwardly opening bags, sepa-- rating the walls of each bag within said housing opening and into said housing, mechanism disposed within said housing and operable to complete the formation of said bags and sever the same from said strip to form separate bags, a conveyoradapted to receive and grip a bag within said housing and advance the same to present the bag to filling and closing stations within the housing, mechanism at said stations operable to open, fill, and close said bag, power driven means disposed outside of said housing for actuating the various ones of said mechanisms in timed relation to each other, actuating members extending through apertures in a wall of said housing and connecting said power driven means and said mechanisms, and flexible seals interposed between said members and said housing wall to permit movement of the members relative to the wall while closing said apertures to retain the gas strips along the sealedportions thereof and form v separate bags, a conveyor for gripping the separate bags and advancing the same successively through a filling station and aclosing station, a bag opening mechanism associated with said bag at said filling station and operable to move the bag walls apart and then release the walls, a

sealing mechanism at said closing station operable to seal the walls of the bag together across the open end thereof, a casing enclosing said mechanisms and having an opening in one wall for the passageof said strips therethrough, saidv sealing elements being disposed outside of said casing, means for introducing a non-oxidizing gas into said casing and maintaining the same Y under pressure therein, a camshaft disposed outside of said casing, cams on said camshaft, actuating members connecting said cams and said mechanisms and extending through apertures in said casing, and flexible seals interposed between said members and said casing walls to permit movement of the members relative to the walls while closing said apertures to retain said gas within said casing. r I

12, In a packaging machine, the combination of, a casing defining av chamber and having a. slit in one end wall thereof, means for introducing a non-oxidizing gas into said chamber, a crosssealing station disposed outside of said casing adjacent said end wall, a cutting station disposed. Within said chamber, and apair of rotatable feed rollers disposed within said casing adjacent. the, inner side of said end wall and between said stations and spaced close together to engage the outer sides of two strips of flexible material lying side by side and pull the strips endwise through said slit to present the strips at said cutting station, the defining edges of. said slit being spaced close together to squeeze air from between said strips as the latter are pulled by said rollers through the slit.

13. In a packaging machine, the combination of, a casing having a slit in one end wall thereof and an exit opening in another wall adjacent the other end of the casing, means for. introducing a gas of predetermined composition into said casing and maintaining the same under pressure, mechanism disposed outside of said casing for supporting a partially formed fiexible walled bag, mechanism disposed within said casing for completing the formation of the bag with an opening in one end thereof, mechanism disposed within said casing for holding said completed bag open, mechanism for delivering a measured quantity of material through a wall of said casing and depositing the same in the. open bag, mechanism disposed within said casing for sealing the walls of the bag together across the open end thereof, and transfer mechanism for advancing said partially formed bag edgewise into said casing through said slit into engagement successively with the various ones of said mechanisms to complete, fill, and seal the bag, and

then advance the same out through said outlet opening.

14.. In a packaging machine, the combination of, feeding mechanism operable to advance along a predetermined path and present to successive bag forming and filling stations a plurality of partially formed bags in the form of a pair of strips of flexible material lying side by side, said feeding mechanism comprising a pair of feed rolls at least one of which is power driven and which engage the strips on the outer sides thereof to squeeze the strips between them and ad- Vance the same through said stations, and a casing enclosing said rolls and said stations with one end wall of the casing disposed adjacent said feed rolls and having a slit therein through which said strips are pulled by the rolls into said casing, the defining edges of said slit being spaced close together to squeeze said strips together and remove air from between them as the strips are pulled through said slit by'said rolls.

15. In a packaging machine, the combination of, a casing defining a chamber, and having an. inlet opening in one end wall thereof in the. form of a narrow slit, means for introducing a nonoxidizing gas into said chamber and maintaining the same under pressure therein, means for supporting a length of bag stock including a pair of strips of flexible material. disposed side by side and lying fiat against each other, feeding mechanism disposed within said chamber adjacent said casing end wall and engageable with said strips to pull the strips through said slit and present the same to across-sealing station and a cut-off station within said chamber, and means: disposed at the respective stations and operable. to seal said strips together; transversely and out the strips intermediate the edges of the seal thus formed, said. slit being defined by parallel flexible edges yie-ldably engagingv saidstrips and spaced close together to squeeze the strips and remove air from between the same asv the strips are miawn by said mechanism through the slit.

16-. In a machine for packaging material in flexible walled bags open at one of their ends, the combination of, means disposed at a filling station. and operable to hold each bag open and deposit a measured quantity of material therein, sealing elements disposed at a closing station and operable to seal the walls of the-bag together across the open end thereof, a casing enclosing said stations and having. a discharge opening. in one wall thereof, means for introducing a gas other than air into said casing and maintaining the same under pressure therein, a conveyor disposed entirely within said casing and adapted to grip. each bag and advance the same successively step by stepthroughsaid filling and closing stations to a. discharge station adjacent said discharge opening, and means for releasing said. bags from said. conveyor at said discharge station.

17. In a packaging. machine, the combination of, a casing defining a. chamber and having a bottom opening therein, means for intro.- ducing an inert'gasinto said. chamber and maintaining the same under pressure therein, a conveyor within saidv chamber operable to carry filled and sealed bags to a point above said opening, means engageable with said conveyor and operable to release each bag from said conveyor at said point, a trapdoor normally closing said bottom opening and adapted to receive each bag as the latter is released from. said conveyor, and mechanism operable. in timed relation to advancev of said conveyor to open said trap door and permit each released bag to fall by gravity from said chamber before release of the next succeeding bag from said conveyor.

18. In a packaging machine, the combination of, means defining a chamber having an outlet opening therein, means for introducing an inert gas into said chamber and maintaining the same under pressure therein, a conveyor within said chamber for carrying filled and sealed bags. to a point adjacent said outlet opening and releasing the bags at said point, a movable door normally closing said outlet opening and adapted to receive each bag upon release thereof from said conveyor, and power driven mechanism engageable with said door and operable in timed relation to operation of said conveyor to open the door for a short period of time and permit the discharge of said released bag from said chamber with the loss of only a small amount of said gas from the chamber.

19. In a packaging machine, the combination of, a casing defining a chamber having a bottom opening therein, means. for introducing a non-oxidizing gas into said casing and maintaining the same under pressure therein, a conveyor within said chamber operable to carry filled and sealed bags to a point above said opening and release said bags at said point, a balanced door normally closing said opening and adapted to receive each bag upon release thereof from said conveyor, and means mounting said door to swing under the weight of each released bag and permit the same to fall by gravity through said opening and from said chamber before release of the next bag from the conveyor.

20. In a machine of the class described, the combination of, means defining a gas chamber maintained under pressure and having a bottom opening, a conveyor within said chamber for carrying filled and sealed bags to a point above said opening and releasing the same at said point, a gate normally closing said opening and adapted to receive each bag upon release thereof from said conveyor, and means associated with said gate and operable to effect opening of the latter and release of the bag from said chamber in timed relation to the operation of said conveyor and before release of the next bag therefrom.

21. In a packaging machine, the combination of, a casing defining a substantially closed chamber, means for maintaining said casing filled with a non-oxidizing gas, a support for holding a flexible walled bag within said chamber and in the collapsed condition with one wall lying fiat against the opposite wall, said bag being open at one end, means disposed within said casing for separating said walls to form an opening and create a vacuum in the bag whereby to draw said gas from said chamber into the bag through said opening therein, filling mecha- 18 nism having an outlet disposed Within said chamber and operable while said walls are held apart to deliver material into the bag through said opening, and sealing means within said chamber engageable with the filled bag to seal the walls of the bag together and thereby close said openmg.

HAROLD L. BARTELT.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,133,367 Wagner Oct, 18, 1938 2,145,941 Maxfield Feb. 7, 1939 2,147,632 Bickford Feb. 21, 1939 2,182,187 Wagner Dec. 5, 1939 2,241,943 Berch May 13, 1941 2,277,288 Berch Mar. 24, 1942 2,292,295 Royal Aug. 4, 1942 2,387,812 Sonneborn et a1. Oct. 30, 1945 2,482,609 Berch Sept. 20, 1949 2,528,680 Berch Nov. 7, 1950 2,546,721 Campbell Mar. 27, 1951

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