US3001342A - Packaging machine - Google Patents

Description

Sept. 26, 1961 K. v. FoRsBERG PACKAGING MACHINE 12 Sheets-Sheet 1 Filed OCT.. 1'7, 1958 2pk.. .k 8

Sept' 26 1961 K. v. FoRsBERG 3,001,342

PACKAGING MACHINE Filed Oct. 1'7, 1958 l2 Sheets-Sheet 2 Sept 25 1961 K. v. FoRsBERG 3,001,342

PACKAGING MACHINE Filed OCT.. 1'7, 1958 12 Sheets-Sheet 3 sept. ze, 1961 Filed Oct. 17, 1958 K. v. FORSBERG 3,001,342

PACKAGING MACHINE l2 Sheets--Sheei' 4 Sept. 26, 1961 Filed Oct. 17, 1958 K. V. FORSBERG PACKAGING MACHINE l2 Sheets-Sheet 5 sept. ze, 1961 K. V. FORSBERG PACKAGING MACHINE Filed Oct. 17, 1958 l2 Sheets-Sheet 5 Sept' 26, 1961 K. v. FORSBERG 3,001,342

PACKAGING MACHINE Filed OCT.. 17, 1958 12 Sheets-Sheet '7 Sept. 26, 1961 K. v. FoRsBERG 3,001,342

PACKAGING MACHINE Filed Oct. 1'7, 1958 l2 Sheets-Sheet 8 Sept 26 1961 K. v. FORSBERG 3,001,342

PACKAGING MACHINE Filed Oct. 17, 1958 l2 SheebS-Sheet 9 Sept. 26, 1961 K. v. FoRsBERG PACKAGING MACHINE 12 Sheets-Sheet 10 Filed OC.. 17, 1958 l2 Sheets-Sheet 11 Filed OOC. 17. 1958 umm www

umm

www

www

wmO

Sept. 26, 1961 K. v. FoRsBERG PACKAGING MACHINE l2 Sheets-Sheet 12 Filed Oct. 17. 1958 www www

United States Fatent Claims priority, application Sweden May 20, 1954 27 Claims. (Cl. 53-112) This application is a continuation-impart of my application Serial No. 717,861, filed February 27, 1958, and now abandoned, which was in turn a continuation-impart of my application Serial No. 490,031, filed February 23, 1955, and now abandoned. This invention relates generally to the art of forming and filling sealed bags or pouches and more particularly to an automatic machine for forming, filling, and sealing a bag or pouch formed from flat film.

With the increasing popularity of the use of pre-packaging in the merchandising of foodstuffs and other merchandise where the material is packaged in individual packages suitable for resale at retail r for unit consumption, a need has arisen for an automatic machine which would form and fill such packages and which could be converted readily to the packaging of a variety of different articles. It is the principal object of this invention to provide a simple machine which fills this need efliciently and economically.

In the operation of this machine the forward edge of a continuous length of strip material, preferably a iiexible film or foil formed of a thermoplastic material, is caught, held, and advanced to a position remote from the initial feeding position. The strip isthen folded in its cross direction at a predetermined distance from its end and the opposite sides of the fold are clamped together at a point removed from the opposed free edges of the folded portion. The material to be packaged is placed inside the folded portion either before or after the clamping action is complete as will be described in detail later. The folded portion is removed from the remainder of the strip and is finally sealed along the three open edges. Provision may also be made for conducting the sealing operation in a sealed chamber whereby the interior of the sealed pouch may, upon sealing, contain either a partical vacuum or a desired inert gas.

The particular machine consists of a means for holding a roll or a supply of film, a means for feeding the film, a reciprocating catching and holding means, adapted to grasp the forward edge of the strip of film at a point adjacent the feeding means and to advance the forward edge of the film toa point remote from the feeding means, a means for forming a transverse fold inthe strip between the feeding means and the catching and holding means; clamping members arranged to engage the two opposite sides of the fold inside the longitudinal edges of the strip; cutting means for removing the fold from the remainder of the strip and means for sealing the three open ends of the fold outside the clamping means.

The details of one embodiment of such a machine can be seen by reference to the drawings in which:

FIGURE l isa perspective View of the machine.

FIGURE 2 is a top View of the feed mechanism with roll 14 and certain other details omitted.

FIGURE 3 is a fragmentary cross-section in the vicinity of line 3 3 of FIG. 1.

FIGURE 4 is a detailed View of theclamping means.

FIGURE 5 is a detailed side view of the sealing device.

FIGURE 6 is a detailed end view of the sealing device.

FIGURE 7 is a simplified detail of a feeding device.

FIGURE 8 is a simplified schematic side elevation of a modification embodying -a vacuum ch-amber.

FIGURE 9 is an enlarged and partially sectional side assiste elevation view showing the arrangement of the elements internally and externally of the vacuum chamber.

FIGURE 10 is a fragmentary side elevation View partially in section illustrating the valve arrangements for exhausting free air from the vacuum chamber.

FIGURE 1l is a cross-section of a modified film feed and cut-off device.

FIGURE l2 is a top view showing the details of a portion of the device shown in FIGURE l1.

FIGURE 13 is a simplified schematic side elevation showing an automatic conveyer feed and filling system.

FIGURE 14 is Va detailed side view of the modied filling mechanism.

FIGURES and 16 are detailed elevations showing in greater detail elements of the mechanism of FIGURE 14.

In FIGURE 1, the frame of the machine is indicated at 8. A roll 9 of a flexible sheet material (indicated at 10) is supported by a shaft which in turn is supported by brackets 11 affixed to frame 8. The film passes over a guide roller 12 and between a pair of feed rollers 14 and 15, placed one over the other and journaled in side plate 13 of frame 8. Identical gears 16 (FIGURE 2) are fixed in meshing engagement to the shafts of rollers 14 and 15 so that when one of the rollers is rotated as will be described later, the other Aroller will move an equal amount but in the opposite direction.

Electric motor 17 mounted on the lower part of frame S drives shaft 2f) by means of a transmission consisting of gearbox 18 and belt drive 19. Shaft 20, which is supported by an extension of frame 8, carries a number of cam disks adapted to cause various synchronized motions in the machine. Shaft 2f) also drives cam shaft 22 journaled above by means of chain drive 21, which chain drive is so arranged that both shafts rotate at the same speed. The speed ofshafts 20 and 22 is such that they rotate one revolution for each cycle of the machine.

Feed rollers 14 and 15 are driven in the following manner. A cam disk 23Yon shaft 20 engages cam fol lower 24 mounted on lever 26, which is pivotally mounted on shaft pivot 25. A swivel rod 27 connects the opposite end of lever 26 to another lever 28 which projects radially from sleeve 29 which is xed to shaft 31 journaled in brackets 30. Semi-circular cradle 32 is fixed to one end of shaft 31 and the two ends of chain 33 are afiixed at diametrically opposed positions at cradle 32.

Chain 33 passes over chain wheel 34 which is fastened to one end of shaft 35 of lower feed roller 15. Through the action of cam 23, cam follower 24, lever 26, swivel rod 27, and lever 28, cradle 32 makes one reciprocal motion for each revolution of shaft 2f).

In order to prevent lower feed roller 15 from having the same reciprocal motion and in order to provide a mechanism whereby the amount of film fed in each cycle of the machine may be adjusted, the lower feed roller `15 which is mounted on shaft 35 is driven in the following manner. The inner face of chain sprocket 34 which is rotatably mounted on shaft 35 is provided with one element 36 of a dog clutch. The cooperating element 37 of the` dog clutch is keyed to shaft 35 in such a way that it may move laterally on said shaft, but is prevented from any rotational movement in relation to the shaft. For the purpose of driving the folding means, which means will be described in detail later, a similar dog clutch arrangement is provided on the opposite end of shaft 35 beyond roller 15. This latter dog clutch consists of clutch member 38 which is fixed to shaft 35 and cooperating clutch member 39 which is fixed to sleeve 40, which sleeve is slidable on shaft 35. The two movable clutch members 37 and 39 are connected by rod 41 which is actuated by spring `42 to normally hold the clutch members axially spaced apart in a disengaged condition. `The rod 41 is also connected to the armature with the roller 15.

of solenoid 43, which upon actuation causes rod 41 to move against the action of the spring and to engage both clutches. Current to solenoid 43 is provided by switch 44 (FIGURE 1) which in turn is controlled by cam disk 45 mounted `on shaft 2.2. The circuit through solenoid 43 is closed during a certain part of each turn of shaft 22 and during this period of time the dog clutches are engaged so the chain wheel 34 is in driving connection Roller drives roller 14 through gears 16. The pressure between feed rollers 14 and 15 may be adjusted in a conventional manner by means of screws 46.

The exact length of film to be advanced during each cycle of operation can be adjusted by adjusting the relative turning positions of cam disks 23 and 45. In so doing, of course, the clutches should be engaged only during that portion of the cycle when chain wheel 34 is rotating in a direction to cause rollers 14 and 15 to advance the `lm. Variations in the length of strip advanced in each cycle can be accomplished by having the clutches engaged before chain wheel 34 begins its motion.

At the beginning of each cycle of operations the forward end of strip 16 of film is in the same vertical plane as cutting member 47. When a new roll of film is inserted, the end of the strip of lm may be advanced to this position by turning shaft 22 manually by means of wheel 48. The first step in the cycle of operations is to catch the forward end of the film with a pair of tongs, which tongs hold the forward end of the film firmly during subsequent operations.

The tongs consist of a pair of upper jaws 49 and a lower plate 50. Upper jaws 49 are separated from each other and are adapted to press the strip against lower plate 50. The lower plate 50 is secured to a horizontal yoke 51 carried by shaft 52. Shaft 52 is journaled in the ends of two parallel levers 53, both of which are secured to a common shaft 55. Shaft 55 is journaled in two uprights 54 attached to frame S. Yoke 51 and associated plate 50 are maintained vin a horizontal position by means of pins or the like which project from the outside of the yoke and slidably engage horizontal guide slots formed in the inner sides of upright 54.

In order to open or close the tongs, jaws 49 of the tongs are secured to shaft 52. An arm 56 which is attached to shaft 52 is connected to the armature of solenoil 57 which in turn is attached to yoke 51. The tongs are normally held open by means of a spring, not shown. The action of the solenoid, when energized, overcomes the action of the spring and turns shaft 52 in such a direction that jaws 49 engage plate Sti and thereby engage any film interposed therebetween.

The advancing and retreating motion of the tong is controlled by lever 53 fastened to one end of shaft 55. Rod 59 (FIGURE 3), which is slidably supported by a support not shown, is hinged to the outer end of lever 58. The opposite end of rod 59 carries cam follower 60 which engages the periphery of cam disk 61 mounted on shaft 22. A spring (not shown) urges the cam follower toward the surface of the cam disk.

In the operation of the machine the open tongs are moved by cam disk 61 toward the forward edge of strip of film, which edge is located in the cutting plane of cutter 47. At the forward end of the stroke, the film is interposed between jaws 49 and lower plate 5t) of the tongs and at this instant cam disk 61 on shaft 22 actuates a contact spring of switch 62 to close an electrical circuit through solenoid 57 thereby swinging the upper tong jaws 49 toward plate 50 to grasp the forward edge of the strip of film. While the grip is maintained the tongs are then returned to their initial position by the action of cam disk 61 and at the same time the rotation of feed rollers 14 and 15 is started to advance the strip.

Thefeed of the strip continues after the tongs have returned tol their initial position, and in timed relation to the'rotation of the rollers 14 and 15 a horizontal ruler 64 is moved downwards to engage the strip in its cross direction between the tongs and the rollers to form the advanced portion of the strip into a fold 65, the depth of which will be dependent on the duration of the feeding. It is obvious due to the folding motion, that ruler 64 must be moved downwards at a speed exactly one-half as great as the feed speed of rollers 14 and .15.

Ruler 64 is driven in the following manner. The ends of ruler 64 are secured in a parallelogram arrangement to chains 66 and 67. Chain 66v passes over chain wheel 69 affixed to shaft 68 and chain wheel 72 which is fastened to shaft 71. Shafts 68 and i1 are journaled in frame plates 13 in parallel arrangement one above the other. Chain 67 passes over sprocket 70 fastened at the other end of shaft 68, a sprocket (not shown) at the end of shaft 71 and sprocket 77 mounted on shaft 76. Chain 73 passes over sprocket 75 which is also mounted ou shaft 76 and over sprocket 73 which is mounted on sleeve 40.

As mentioned above clutch member 39 connected to sleeve 4i) is engaged at the same time as roller 15 is connected. As a result chain 67 causes shaft 68 to rotate simultaneously with roller 15 so that horizontal roller 64 is moved in a downward Vdirection during the time that strip 1t? of the film is being advanced. The diameters of sprockets 75 and 77 are so dimensioned that ruler 64 moves at half the peripheral speed of rollers 14 and 15. When the clutches of shaft 35 are disengaged, the rotation of the feed rollers 14 and .15 and the downward movement of ruler 64 ceases simultaneously. When the drive to ruler 64 is released the ruler is quickly returned to its upper or rest position by means of helical spring '78 which is inserted between shaft 68 and frame plate 13. For reasons which are obvious, the distance between the rest position of the ruler and the position at which the ruler first contacts the film is adjusted so that the distance is equal to one-half of the horizontal distance traveled by the tongs during the retreating'position of the stroke. Y

The fold having 1been formed, the next step in the operation is to place the material to be packaged into the fold. T he exact sequence of operations of this particular step depend to a large degree upon the nature of the material to be packaged. Where, for example, the material to be packaged consists entirely or partially of a liquid, or consists of a plurality of small pieces, it is important that the open ends of the fold 65 be pressed together to form a pocket that is open only on the top and is entirely tight along the side edges before the goods are inserted in the fold. lf, on the other hand, the goods to be packaged consist of material such as slices of meat, which is substantially dry and which has structural stability, it is possible to place such material into the fold before the open ends of the fold are pressed together. InV either case, since the seams which are formed later are formed by pressing or by heating and pressing, it is important that the edges of the film of the fold in the area where the seal is to be made be kept dry and clean.

In the case where the material to be packaged is partially fluid and for that reason the side edges of the fold must be closed before the material is placed into the fold, two clamps are arranged to grip the folded portion of the strip, one clamp slightly inside of each edge. The two clampsV are also arranged to move a slight distance upwards and towards each other after gripping the fold so that the fold of film between the clamps opens slightly and Vthereby becomes easier to fill. The details of the construction of such a device is shown in FIGURES 1, 3, and 4.

The two clamps have the approximate shape of atjawed pliers 79 (FIGURE 4) the jaws of which are carried by two parallel, horizontal shafts 80 and 81. The shafts S0 and 81 are journaled in vertical plates 82 secured to the ends of horizontal plate 83 (FIGURE 3). Plate S3 is supported by and guided on verticalcolumns 84 in such a manner that plate 83 can be moved vertically. A bell crank 35 is fastened to the end ofshaft 80 sperma and another bell crank 86 isfastened to the end of shaft 81. As seen in FIGURE l and FIGURE 4 the two bell cranks cooperate with each other in that ya pin at the end of one bell crank engages in a slot at the end of the other. A compression spring 87 is disposed between the opposite ends of the bell cranks to maintain the cranks in a normally closed position. 'Ihe two bell cranks are actuated by means of a link 88, one end of which is pivotably mounted on Abell crank 85 and the other end of which is connected to lever 89 which in turn is pivotably `mounted on the frame. The free end of lever 89 carries cam follower 90 which contacts the periphery of cam disk 91 mounted on shaft 22. The arrangement is such that cam disk 91 holds the pliers or clamps 79 open during a part of its rotation and during the rest of its rotation permits spring 87 to compress them.

The jaws of pliers 79 are secured to sleeves 92 and 93 (FIGURE 3) which sleeves are capable of axial movement along shafts 80 and 81, but are prevented from rotational movement by means of key-ways formed in the shafts. The sleeves 92 carrying one pair of pliers 79 may be fixed by set screws to shafts 80 and 81 in a position determined by the size of the package. Sleeves 93 of the second pair of pliers 79 are connected by means of a transverse plate 94 which plate may bemoved toward sleeves 92 along shafts 80 yand 81 against the action of springs 95. The motion of plate 94 is controlled by rod 96, one end of which is fastened to the side of plate 94 and the other end to support 82. A sleeve 97 is rotatably journaled on rod 96 and has one end shaped as a cam surface which contacts pin 98 inserted in rod 96. Sleeve 97 in turn is connected to one end of a lever 99 (FIG- URE l). The other end of lever 99 is connected by means of a swivel rod -100 to another lever 101 which is pivotably journaled on the same shaft pivot as lever 89. The lever 1 carries a cam follower which contacts the periphery of cam disk 102 mounted on shaft 22. Thus, when lever system 99-101 is actuated by cam disk 102, sleeve 97 is turned so that its cam surface engages pin 98 to force rod 96 and therefore pliers 79 which are fixed to sleeves 93 slightly inwards against the action of springs 95.

Plate S3 is moved vertically by double-armed lever 103 (FIGURES 3 and 4) which is pivotably journaled in support 104. One of the ends of lever 103 is linked to the under side of plate 83 and the other end of lever 103 carries a cam follower 105 Which contacts the periphery of cam disk 106 secured to shaft 22.

In the operation of the pliers 79 by means of the mechanism just described, the pliersgrasp the fold of the strip of film as soon as ruler 64 has returned to its initial position. Thereafter table 83 is lifted and one pair of pliers 79 is moved inwardly substantially simultaneously. These movements tend to open the free edge of the pocket so that filling will be facilitated. The clamps 79 are maintained in this position during both the filling and the cutting operations.

A device specially designed to facilitate the filling is shown in FIGURE l and in FIGURE 7. Funnel 107 is suspended between the upper ends of two parallel, approximately vertical rods 108. The lower ends of rods 108 are connected by means of a horizontal rod 109. The rods 108 are slidably supported by guide bushings 110 mounted on the frame at an intermediate point on rods 108. The portion of rod 109 between rods 108 is surrounded by sleeve 111 which is formed at one end of bell crank 112. Crank 112 is rotatably supported by shaft 31 and its opposite end is coupled to a lever 114 which is journaled on shaft pivot 25 by means of link 113. Cam follower 115 which is mounted on lever 1f14 contacts the periphery of cam disk 116 which is mounted on shaft 20. Cam 116 is so constructed as to hold funnel 107 in a raised position. At the proper time in the cycle of operations the funnel is lowered so that its orifice is a little below and inside theopening of the pocket, thereby keeping the rop sealing edge ef the pocket clean to' facilitate (i sealing. The material to be packaged can be placed' into the funnel either manually .or automatically either when the funnel is in its raised position or in its lowered position. After a suicient time for filling, the funnel is returned to its raised position.

Funnel `107 is formed in a wedge shape (with two rectangular sides and two triangular sides) so that it may be introduced into the openingof the pocket. The rearmost rectangular side 117 acts as a shutter, the upper end of which is attached to shaft 110. Shaft 118 is journaled in brackets 119 which project from rods 108. A bell crank 120 is affixed to one end of shaft 118. One end of bell crank .120 is drawn inwards towards adjacent rod 108 by spring 121. The other end of the bell crank 120 is linked to a rod 122 which extends downwards and is guided in Va sleeve 123 fastened to rod 108. Rod 122 carries a projecting pin 124 which is so positioned as to engage stop 125 on the frame of the machine when funnel 107 is lowered. Shutter 117 of funnel 107 is maintained in a normally closed position by means of ratchet Wheel 126 secured to shaft -118 outside bell crank 120 and rockable pawl 127. i

In the operation of the funnel, as the funnel is moved downwards, pawl 127 is lifted by pin 128 projecting from the frame. This pin is located on the frame so as to actuate the pawl when the lower end of the funnel has been introduced into the opening of the pocket. When pawl 127 is lifted, ratchet 126 is released and bell crank 120 is drawn by spring 121 so as to open shutter 117. When the funnel is returned to the initialraised position, pin 124 on rod 122 hits stop 125 whereby rod 122 is drawn downwards, thereby returning shutter 117 to its closed position and permitting pawl 127 to again lock ratchet wheel 126.

Since funnel 107 is kept closed until it has been introduced into the opening of the bag, the goods to be packaged may be placed in the funnel, even while the funnel s in its raised position. Doing so reduces the time necessary for the lling operations. At approximately the same time as funnel 107 returns toits raised position, the elec` tric current energizing the solenoid 57 is cut off, thereby releasing the upper jaws 49 of the tongs from lower plate i 50 thus releasing the end of the strip. At approximately the same time plate 83 is returned to its lower position and clamps 79 are permitted to return to their outer position.

Also, at approximately the same time,rcutting member 47 is actuated to cut the filled pocket from the rest of the strip.` Cutting member 47 consists of a knife having one end pivoted in the frame. The other end of the knife is connected to one end of double-armed lever 130 which is pivoted in supports 131 by means of a link 129. The opposite end of lever 130 carries a cam follower which contacts the periphery of cam 132 mounted on shaft 22. The cutting action is between cutting member 47 and horizontal knife 133 which is mounted on the frame.

By virtue of the several actions the two ends of the now filled folded portions are released and the film in the folded portion is stretched towards a flattened position to facilitate sealing. The actual sealing operation can be performed by many of a number of known sealing devices, the most convenient of which, if the film is made of a thermoplastic material, supply heat under pressure.

The arrangement of the sealing device is shown in FIG- URES 5 and 6. Two rectangular plates 134 are arranged j opposite each other on either side of the folded portion of the iilm. Each plate is carried by parallel arms 135 and 136 and each pair of parallel arms is secured toa shaft 137 journaled in the frame. The shafts 137 of the two plates are arranged in parallel to and at some distance from each other. A pair of stub levers 13S, each of which is formed as an extension of respective arms 135, cooperate with each `other in a pin or slot arrangement so that 'both plates are movedsimultaneously in opposite directions when one of the shafts is rotated. An arm 139 is fixed to one of the shafts 137. Arm 139 isiconnected to lever 141 which pivoted in the frame by @sans ai a 7 link 140. Lever 141 carries a cam follower 142 which is in Contact with the periphery of cam disk 143 mounted on shaft 22.

Each plate 134 is provided with three metal heater elements 144 (FIGURE 6) on the side adjacent the film. Heater elements 144 contain insulated resistance coils connected in series by wires 145 which in turn are connected to asource of electricity. It is preferable to cover the heater elements 144 with a thin coating of a heat resistant, non-adherent substance such as poly (tetrauoroethylene) e.g. Teflom and the heater elements 144 are so arranged that in combination they will press together from both sides of the film along the three open edges of the film outside the clamps 79.,

As shown in FIGURE 6 guide slots suchas horizontal guide slots 146 may be provided in both above-mentioned plates 134 so that one or more of the heater elements 144 may be moved to adjust to the size of the bag. The temperature of the heating elements may be controlled in a conventional manner such as by a thermostat, not shown.

Cam 143 is adjusted to actuate lever system 139-141 to advance heating plates 134 toward the bag and link heating elements 144 into pressing contact with the film immediately after the machine has completed the operation described above. After a suitable time has elapsed for sealing the film the cam permits lever system 139- 141 and therefor plates 134 to return to their normal opened position by the action of a spring not shown, which may be mounted in some suitable place.

After heating plates134 have returned to their normal open position clamps 79 are released and returned to their normal open positions. The filled and sealed pouch, since it lacks any support, falls, and is discharged from the machine through chute 147 shown in FIGURE l.

At this point in the cycle, all of the parts of the machine roll 9. The material from this roll passes over roller 12 beneath film and can provide a partial or complete overwrap of the pouch depending upon its width. A narrow strip, intended for identification purposes, is indicated at 150. This second strip should be made of a thermoplastic material or should have its upper surface coated with a thermoplastic material so that it may adhere to the pouch during the sealing operation.

A modified version of the machine adapted to provide pouches which are sealed in the presence of either a vacuum or an inert atmosphere is shown in FIGURES 8, 9 and l0 of the drawing. These drawings are somewhat simplified in view of the fact that the majority of the elements are the same as in the machine described above.

As shown in FIGURE 8, the modified machine is pro vided with a frame 204 having oppositely disposed brackets 265 which rotatably support thereon a roll or web 266 of a package forming material, which material is at least pressure scalable and is preferably heat and pressure scalable. A continuous strip 297 of material from web 206 is advanced longitudinally and intermittently between feed rolls 208 by a feed or advancing mechanism. Grippers 210 are provided for advancing the strip of material in cooperation with the feed mechanism supported on support members 209. The grippers 210 in their normal position are remote from feed rollers 208 but may be advanced toward rollers 208 and are adapted to grip the leading edge lof strip 297 then to pull the leading edge of strip 207 through the conversion zone of the machine where subsequent conversion operations are performed in forming the package and filling it.

After the grippers 210 have gripped the leading edge of the strip` of filmv andV as the grippers return to their normal advanced position a cyclicallyfoperated straight edge, not shown, which is disposed acrosslthe strip atV a point between grippers 210 and feed-rollers208is moved downwardly to `fold the section of film transversely and thereby form a depending bag or container section. -Ro'll-` ers 208 advance Va sufficient length of film to form a fold and the straight edge is returned to its initial raised position.

In a position on the machine immediately beneaththe area defined bythe stroke of grippers 210l there is disposed an air-tight vacuumizing chamber consisting of a body portion 211 mounted in a fixed position on the frame of the machine and a pivotably mounted cover portion 2.12 which is cyclically operable between a closed and an open position. In FIGURE 8 vcover portion 212 is shown in its closed position in solid lines and in its open position in broken liners. Coverr212 is supported by two extensions 213 `disposed on opposite sides ofthe cover. Extensions 213 are pivotably mounted on shaft 214 which extends between them and is supported by a bracket mounted on the frame. A spring 215 constantly urges cover 212 toward the open position. A linkage system designated generally as 216 and provided with a cam follower as shown is actuated by cam 213 so that when so actuated the force of spring 215 is overcome and the cover is held in a closed position. Cam 218 is mounted on shaft 217 which shaft corresponds to shaft 22 in FIG- URE l. Cover 212 is maintained in an open position until the folding operation is completed on the fiim. At the end of the fold-ing operation the depending container section is disposed in a position generally between the open portions of the chamber with the lower portion of the fold extending somewhat lower than the upper end Vof the open chamber portions.

While the folded container section is in this pos-ition it is filled with the `material to be packaged therein. The filling operation is identical to that described above and the folded container element may begripped as above.

Transfer pincers (FIGURE 9) consisting of a pair of cooperating plates 219 and 220` are provided to support the folded container sections while being filled and to transfer the filled container sections into the vacuum chamber after the filling operation is complete. These pincers are illustrative of the type that maybe used if it is not necessary to roll the edges of the fold against leakage. Plates 219' and 22@ are fixed to a pair of ce yoperating cranks 221 and 222 pivotably mounted on pins or pivots 223 and 224 disposed in a block 225 which block is displaceable between a raised and a lowered position by connecting rod 227 which is fixed to the lower portion 226 of block 225 as shown. Rod 227 enters the vacuum chamber through a stuffing box 22S. Rod 227 is displaced in an axial direction by a lever mounted on pivot 23%)? and provided with a cam follower 231 which rides on the profile of cam 232. Cam 232 is Imounted on shaft 233 which connects to shaft 20' in FIGURE l and is contoured to raise and lower the transfer pincers in timed relationship with the container section folding operation so that the pincers are in the raised position during the filling operation.

This arrangement is shown in greater detail in FIGURE 9 wherein pincers 219 and 220 are shown in their lower position inside the closed vacuum chamber. Crank 222 is provided with a pin 234 engaged by a forked portion of crank 221. A spring 235 constantly urges the pin 234 downwardly so that the cranks 221 and 222 tend to be rotatably driven in opposite directionsv and the plates 219 and 229 are constantly urged towards a face-to-face position.

The crank 221 is provided with a projection 236 on the end of which is provided a roller 237. Roller 237 is adaptedto ride on the face of head 238 at all times whether the block 225 is in its raised or its lowered position. Roller 23'7 is maintained in contact with head 238 by means of the force exerted by spring 235.

Head 238 is mounted on connecting rod 239 which entersthe vacuum chamber throughl stuffingbox 240. The

opposite end of' rod 2359 is provided with a cam follower, not shown, which cooperates with a cam, not shown,

which is mounted on shaft 217. spring 241 mounted around connecting rod 239 forces the cam follower into contact ywith the cam. By means of this linkage head 238 may be moved to the right and to the left as shown in FIGURE 2. When the head is in its normal left hand position, the transfer pincers are in their open position. When head 238 is in its right hand or advanced position, the pincers are in their closed position.

In the operation of the machine the pincers are maintained in their open and raised position during the folding operation. The pincers are closed in timed relationship with the filling operation. After the filling is cornplete, and the pincers closed, the forward end of the strip of Ifilm is released by grippers 210 and the folded section is severed from the remainder of the film by means of a cutting device, not shown. While the pincers Vare maintained in their closed position to grasp the container section, the pincers are moved in their lower position by the action of cam follower 231 and cam 232. At this point the severed container portion is entirely within the vacuum chamber and the cover 212 of the vacuum chamber is then closed by the action of cam 218 as described above. It Will, of course, be understood that the forward edges of cover 212 and body portion 211 of the vacuum chamber meet in mating arrangement and are provided with a suitable gasketing member to form an air-tight fit.

The air within the closed vacuum chamber and therefore within the container section is removed by a vacuum pump or other suitable source of vacuum, not shown. The chamber body 211 is provided with an opening 242 (see FIGURE l) which provides communication between the interior of the chamber and a valve housing 243 mounted on the side of the chamber. Housing 243 is provided with a port 244 which communicates with duct 245 which leads to the vacuum source. A piston 246 reciprocates in the housing 243 and opens and closes the port in timed relation with the opening and closing of the vacuum chamber. Piston 246 lis fixed to a connecting rod 247, at the other end of which is provided a cross head 248 which is fixed to a `link 249 which extends substantially parallel to connecting rod 247 but externally of the housing. Link 249 is pivotably connected at 250 to the one end of lever 251 which in turn is pivotably mounted at its mid point by pin 253 to bracket 252. The opposite end of lever 251 is provided with cam follower 254 which cooperates with the profile of cam 255 which is mounted on shaft 233. A spring 256 is provided to urge the cam follower into contact with the cam. Cam 255 is so profiled that when portion 257 is in engagement with follower 2'54, piston 246 maintains port 244 in a closed position. When follower 252 drops into the recessed portion of the cam as shown in FIGURE piston 246 is withdrawn thereby placing port 244 into communication with the interior of the vacuum chamber. The cam is so contoured that vacuum'is drawn on the chamber only when the chamber is closed.

In the event that it is desired to charge the interior of the packing section with an inert atmosphere such as an atmosphere of nitrogen, a mechanism for admitting such a gas into the chamber after the vacuum has been drawn can be provided.

For the purpose of sealing the individual container sections and thereby forming permanently sealed packages, heat and pressure applying sealing are provided internally in the vacuum chamber. I have found that if the heater elements are constructed according to FIG- URES 5 and 6 wherein separate elements are provided for the top seam and the ftWo side seams but al1 elements are applied to ythe lm simultaneously there may exist, under certain conditions, minute cracks between the top seam and the side seams which permit the entry of air. For this reason, when making a partially vacuumized package, or a package that is filled with inert gas, I prefer` to use either a pair of continuous heating elements so i@ that a continuous seal is formed about all three margins" of the pouch in cases where a single size'A pouch is to be made on the machine or to provide for the sequential operation of the heating elements as will be described in detail below .where adjustability is necessary.

In the preferred embodiment of the latter instance, one set of heater elements is mounted on cover 212. These are indicated in FIGURE 9` as parts 258` and 259 wherein part 258 is a heater element provided for the top seam and 259 is one of a pair of heater elements provided for the side seams. The other element in this pair is omitted for clarity in the drawing. Cooperating top seam heater element 260 is attached to connecting rod 261 which is guided in guide 262. The other end of rod 261` is journaled in crank 266 as indicated at 269. Crank 266 is pivotably mounted mounted on shaft 268. Side seam heating elements 263 which cooperate with the corresponding elements 259`are mounted on a plate 264 which is connected to connecting rod 272 which is supported in guide 265. The opposite end of connecting rod 272 is journaledas indicated at 270 to the end of crank 267. The other end of the crank 267 is pivotably mounted on shaft 268i. Cranks 266 and 267 may be moved from a position wherein the corresponding heater elements are out of contact With the film to a position where the corresponding heaterelements are in pressing contact with thefllm. For 'the sake of clarity the drive mechanisms are not shown in detail. However, to each crank there is attached a rod such as that shown in the case of rod 271 attached to crank 266. Each rod passes through a stulfing box similar -to stufling box 240 and is driven in a manner similar to rod 239 by cams mounted on shaft 217. i t

To provide for adjustability of package size, plate 264 is provided with slots so that elements 263 may be moved at will.` A similar provision is made in the plate on which `element 259 is mounted. In the event that a single size package is to be made, it is desirable to provide a single `sealing element which would form a continuous seal about all three margins-of the package, elements 258 and 260-n1ayV beY removed and the continuous element substituted for elements 259 and 263. In such an event crank` 266 would either be inactivated or removed.

With separately actuated elements 260 and 263, either element may be actuated before the other. In the normal operation the side seal is formed first by moving crank 267 toits forward position. The crank 267 is then returned to its normal position so that elements 263 are removed from the film and rod 227 is elevated slightly to elevate pincers 219- and 220 and thus lthe pouch. 'Ihereupon crank 266 is actuated to form the top seam through the cooperation of heating elements 258` and 260. In this manner,` a slight overlap of the side seams and the top seam may be provided, thus avoiding the possibility of a minute passage being formed.

Alternatively, it is sometimes preferable tto form the top seam prior to the side seam. This is particularly true where the particular film used has a tendency to roll up with theiapplication of heat. In this event crank 266 is actuated first and after 'this crank has` been permitted to return to its normal position, the pouch is lowered slightly by movement of rod 227, and then crank 267 is actuated.

Another alternative, a variation of the action described in the preceeding paragraph, permits the formation of superior side seams in instances where the film used is very flexible and is liable to form wrinkles in the seam unless the area to be seamed is maintained under tension. Under these circumstances it is preferable to replace pincers 219 and 220 with the type illustrated in FIGURES 4 and 5 where the film is grasped near its edges and outside the material to be packaged and where the pincers are capable of limited lateral motion. The pincers are spread to stretch the film laterally before crank 266 is .i actuated to form the top seam. Then crank 266 is re turned vto its normal position and the pouch is lowered slightly by the movement -ofrod 227 to permit the side seam `portions to overlap the :topseam. However, before crank 267 is actuated, crank 2166 is reactuated to bring top seam heating elements 258 and 260 into contact with the film. Rod 227 is *then lowered a slight additional amount to bring the film in the side seam area underV tension and iinally crank 267 is actuated to 'form the side seams.

After the individual packages are formed and sealed, the'vacuum in the chamber is broken by a valve consisting of a disk valve member 273 which seals opening 274 provided in the wall of body portion 211 of the vacuum chamber. The spring 284 placed between the valve 27 3 and the machine frame work shown as 276 constantly biases valve disk member 273 to a seated position. One end of operating rod 275 is connected to valve member 273 and the other end is connected to lever 279 by a pivot shown in 278. Lever 279 in turn, is pivotably mounted on a pivot 280 on the bracket 281. Cam follower 282 is mounted on the opposite end of lever 279 and this cam follower rides on the periphery of cam 283 mounted on shaft 233'. The action of spring 284 urges cam follower 282 into contact with cam 283. Cam 283 is so contoured that following the sealing of each container section it actuates lever 279, therebycompressing spring 284 andunseating valve 273 to break Vthe vacuum.

Immediately after the vacuum is released cover 212 is returned to its open position and the pincer plates 219 l2 guration of the tongs comprising the catching and holding means as shown in detail in FIGURES ll and l2.

As Vshown in FGURE `-ll, a lrn supporting means indicated'at 301 is provided between feed rollers 14 and and 220 are released, thus releasing the sealed package.

The package drops into chute 285 which is fixed to support block 225. and s raised and lowered therewith.

Cover member 212 is provided with a normally closed gate 283 which seals opening 289 in the wall of cover 212. Gaite 283 is provided with a packing member 287 for effecting an airtight seal and is fixed to an arm of a twoarm lever 290 pivotably mounted at its mid point in pivot 291 on bracket 292. vThe upper arm of lever 290 carries a ruler293 which engages the bevelled lower surface of bracket 294 which in turn is fastened to the frame of the machinelalong side the vacuum chamber. The bevelled lower surface of bracket 294 is so shaped as to Vcause gate 283 to open as cover 212 opens. A spring, not shown, urges gate 288 toward the closed position.

Numerous modifications of this machine are possible to meet special circumstances or operating conditions without departing from the basic operations of fthe machine or the basic concept of the invention. An exemplary number of such variations is shown in FIGURES 1l through 15.

it will be appreciated that the operability of the iilm feed and the film catching and holding means disclosed above depends in part upon using a plastic film that has sufficient rigidity that the forward end ofthe strip of iilrn extending slightly beyond the cutting member (eg. 47) should not bend under its own weight, Otherwise the end of the film would not be in a position to be gripped by the catching and `holding means (eg. the tongs indicated at 49 andV 50). Most flexible iilms are sufliciently rigid that the small length of film extending Vbeyond the cutting means does not deilect under its own weight suiiiciently' to cause any difficulty. However, there are `certain limp films which are insuiiiciently rigid, either due to the thinness of the gauge of the film or due to the inherent physical characteristics of the substance forming l the film, that the projecting end portion will not stick out but rather willfold downwardly, thereby falling out of reach of the catching and holding means.

In such instances the apparatus for the present invention canV be modified by providing a lm supporting means; by adjusting the length of the forward stroke of the cat-ching and holding means; and by revising the con- 15 and cutting member '47. Film supporting means 301 consists of support block 3&2 which extends across the width of the apparatus and is fastened to the frame, support plate hinge 303 fastened to the rearward edge of block 392 and film support plate 304 which is located above block 302 and attached thereto by means of hinge 303. Spring 30S which is inserted in recess 306 in the upper surface of block 302 normally urges the forward edge of plate 304 away from the upper surface of block 302. The extent to which plate 304 is urged away from block 302 is controlled by plunger 315 which passes through spring 30S and extends through block 302. Adjustable vstop ring 316 fastened to the extremity of plunger 315 beyond block 302 provides for the adjustment of the distance.

Film 10, when advanced by rollers 14 and 15,rides on top of support plate 304. Support plate 304 extends to a point just short of the cutting line of cutter blades 307 and 308 attached to cutting member 47 and to support block 302 respectively. The rearward side of cutting member 47 is provided with spring loaded depresser member 309 which consists of depresser foot 311, depresser foot support block 312, spring member 313, and adjustable stop ring 314. Spring 313 urges the lower face of depresser foot 311 downwardly, and the length of the stroke is adjusted by stop ring 314 so that the depresser foot 311 is out of contact with iilm 10 when the cutting member 47 is in its raised position. However, when icutting member 47 is actuated during the cutting portion of the 'cycle of the apparatus, depresser foot 311 contacts the surface of iilm 10 and depresser support plate 304 until support plate 304 cornes into firm contact with support block 302 before the knife blades 307 and 308 both Contact the lrn. The force exerted by spring 313 on `support plate 304 is of course, suiiicient to overcome the force exerted by spring 305.

The outer extremity of each of upper jaws 49 and lower plate 50 of the tong mechanism are provided with extender plates 317 and 318 respectively. These extender plates extend between the blades 307 and 308 when the tong mechanism is in its fully extended position. As shown in FIGURE l2, the outer edge of extender plates 317 and 318 and the outer edge of support plate 304 are serrated, the serrations on support plates 317 and 318 matching and interiitting the `serrations on plate 304. The preferred form of interfitting serrations are the square notches shown in FIGURE l2, although other configurations of notches may be employed with equal effectiveness.

In this manner film 10 is supported at least in part to a point beyond that where it is contacted by the iilm catching and holding means. In addition, the lifting action of support plate 304 insures that extension 318 of plate 50 will `clear the iilm during the advanced stroke even if there is a slight drape of the film in the notched areas ofthe forward edge of plate 304 or if the end of the iilm extends slightly beyond the edge of plate 304.

An example of another possible modification of the apparatus is shown in FIGURES 13-15 which illustrate an automatic conveyor feed and a iilling system especially adapted for use when packaging solid material having a reasonably regular shape and capable of being handled as a unit, such as, for example, half pound to one pound units of sliced cheese or sliced luncheon meat. In FiG- URE 13, an apparatus similar to that shown in FIGURE 8 is provided with a supply conveyer V321, which is provided with a plurality of pockets for individual units, a retractable transfer conveyer 322 and a specialized feedingr device 323. In the operation of this modified apparatus, 'after each unit is prepared for packaging, the operator merely 'places the unit Vin the next vacant pocket oh supply conveyor 321. Thereafter the device, as will be described in more detail below, automatically packages each unit without requiring the further attention of the operator.

Conveyer 321 passes, over rollers 324 and 325 which are mounted on shafts 326 and 327 respectively. Shafts 326 and 327 are journaled to side plates 328 which in turn are fastened to frame 329. Conveyer 321 consists of a plurality of individual bands arranged side by side with a space approximately equal to the width of each band between each band. Projections 331 arranged at equal spacings at the outside of each band provide the end walls of pockets 332.

The drive for conveyer 321 is provided by a linkage consisting of crank 334 fastened to the end of shaft 333, tie-rod 335 and drive plate 336 rotatably journaled on shaft 327. Drive plate 336 is provided with a pawl 337 which engages in slots 339 located at properly spaced intervals along the outer edge of drive wheel 338. Drive wheel 33S is fastened to shaft 327. Shaft 333 is' connected by a one-to-one pulley drive 341 to shaft 233. It will be remembered that shaft 233 makes one revolution during each cycle of the machine and therefore because of the one-to-one drive, shaft 33-3 also makes one revolution per cycle of the machine. The motion of drive plate 336 and the action of pawl 337 engaging in slots 339 advances the conveyer 321 a distance exactly equal to the length of one pocket for each cycle of the machine.

Retractable transfer conveyor 322 consists of a plurality of bands having the same width and the same spacing as the bands of conveyor 321. The bands comprising conveyor 322 pass around rollers 341 and 342. Roller 341 is rotatably journaled on side plates 323. Roller 342 is rotatably journaled in conveyor side plates 343 which in turn are rotatably journaled on roller 341. Crank 344, rotatably journaled on roller 341, is attached to s ide plates 343. The outboard end of crank 344 is attached by a linkage consisting of rod 345 and crank 346 to cam follower 347 which rides on the surface of cam 348, which in turn is attached to shaft 333. Conveyor 322 is driven by a suitable drive (not shown) attached to shaft 324 and hence conveyor 321.

A slide 349 is provided between conveyer 321 and feed conveyer 322. Slide 349 consists of ya plurality ofparallel metal strips arranged to lie in the spaces between the bands forming both conveyor 321 and feed conveyor 322. Slide 349 is attached to side plates 328.

Feed device 323, which will be described in greater detail below, has a lower jaw which consists of a series of parallel fingers 360 which are arranged to lie between the bands which make up conveyer 322.

In the operation of the machine, individual units to be packaged (indicated at 351), are placed in consecutive pockets 332 of conveyer 321. During each cycle of the operation of the machine, conveyer 321 advances a distance equal to the length of one pocket.

pocket 322 is released successively on to slide 349 and thence on to conveyer 322. The action of conveyor322 moves the unit over the fingers 360 of lower jaw 352 of feed device 323. After this occurs, through the action of cam follower 347, riding on the contoured surface of cam 343, conveyer 322 is downwardly rotatably retracted around shaft 341 to the position shown in FIGURE 13 in dotted lines. In the retracted position, conveyer 322 is ont of the way of the movement of feed device 323. After feed device 323 has returned to its normal position, the action of cam 348 returns conveyor 322 to its normal raised position and the apparatus is in position to supply another unit of material tothe feed device at the proper interval in the sequence of operations.

Feeding device 323 (FIGURES 14 and 15) consists of As a consequence, the units of materials 35i contained in each` to be used in conjunction with conveyer 322. In this case, the fingers 363 are designed to it between the bands which form conveyer 322. Fingers 360 of lower jaw 352 are attached to and supported by bars 354 and 355 which run across the width of the apparatus and are in turn attached 4to a pair of end plates 356, one of which is l0- cated at each end of bars 354 and 355.

Upper jaw 353 may also be composed of fingers 357 which are located in parallel and matching relation with fingers 360 and lower jaw 352. Fingers 357 are attached to and supported by bars 358 and 359 which likewise run across the width of the apparatus and are attached to and supported by a pair of end plates 361 one of which is located at each end of bars 358 and 359. End plates 361 are attached to and separated from end plates 356 by a pair of levers 362, the upper ends of which are rotatably journaled on shaft 363 which passes through end plates 361 and the lower ends of which` are rotatably journaled on shaft 364 which passes through end plates 356.

The jaws are maintained in a normally open position by the action of spring 365 which is mounted between bar 359 of the upper jaw 353 and rearward extension 36 6 of a linger `360 of lower jaw 352. The action of spring 365 tends to pull lever 362 to an upward position which in turn pulls upper jaw 353 to an upward and backward position relative to lower jaw 352.

The upper and lower jaws are moved to a closed position by the `actions of levers 367 and 363. Gne end of levers 368 is rotatably journaled at `374i on end plates 356 and the other end is `rotatably journaled at one end of levers 367. 'Fhe opposite end of levers 367 is rotatably journaled to shaft 36:3 at the end of levers 36-2. One of the pair of levers 36S is provided with an angularly disposed extension 369 which extends above and in the general direction of lever 367. Wheel 371 is rotatably journaled to the end of extension 369 of lever 368. When wheel 371 is pressed toward end plate 356 the action of levers 362 and 367, and 368 rotates levers 362 forwardly around shaft 364. This causes upper jaw 363 to move forward and toward lower jaw 352. Cam 372 with a raised portion and a notched portion is rotatably journaled to end plate 356 at 370 and is aiiixed to lever 36S. As wheel 371 is depressed and as lever 362 is rota-ted forward-ly about shaft V364, lever 363 is rotated forward about i pivot 370. This rotates cam 371. After this motion has continued to the desired degree and the -two jaws have achieved the desired proximity, spring loaded locking arm 373 engages the notch in cam 372. Spring loaded locking arm 373 consists of locking stub 374 and locking arm extender 375 both of which are aixed to shaft 376 which in-turn isrotatably journaled to end plate 356. Locking stub 374 and locking `arm extender 375 are located on opposite sides of end plate 3'56. After locking stub 374 has engaged the notch on cam 372, pressure on wheel 371 can be released without releasing the jaws.

`'Ihe rotation of cam 372 Ias the jaws close brings the raised portion of cam 372 into an upward position in the view as shown in FIGURE l5. Side plate 361 of upper plate 353 is provided with a rearward extension 377.

`Extension 3-77 is provided with a wheel 378 which is rotatably journaled thereon in a proper position to contact the raised portion of cam 372 when upper jaw 353 has been depressed toward the lower jaw 352 to the desired extent. The interaction of wheel 373 and the raised portion of cam 372 forces the forward endiof fingers 357 of upper jaw 353 toward the forward end of fingers 360 of lower jaw 352. There is a further extension 379 of extension 377 which is angularly disposed to end plate 1316i at a point beyond the location of wheel 37B. The end of extension 379 is provided with a wheel 331 rotatably joura lower jaw 352 and an upper jaw 353. Lower jaw 352 p naled thereon, the function of which will be described below.

Feed mechanism 323 is aixed to the machine and operates in the following manner. The machine is pro- 15 vided with a pair of upstanding side plates 382. vSide plates 382 are provided with a pair of parallel slots 383 and 384. Feed mechanism 323 is provided with two pair of rollers 385 and 386 adapted to engage respectively in slots 383 and slots 384. Rollers 385 are rotatably journaled at the ends of shaft 364 beyond end plates 356.v Rollers 386 are rotatably journaled to end plates 356. The center of rotation of roller 386 and the center of rotation of roller 385 are located on the apexes of the extremities of the hypotenuse of a right triangle, the sides of which lie in a vertical and horizontal plane respectively, and have a length equal to the center spacing of Slots 383 and 384. Slot 383 is longer than slot 384 by a distance at least equal to twice the distance between the center lines of slots 383 and 384, the excess length being applied equally to both ends of slot 383. Rollers 335 and 386 both have a diameter substantially equal to the width of slots 383 and 384 respectively. Rod 387 which is the same as rod '122 of FGURE l, and which operates in an identical manner is rotatably journaled to shaft 364. As in the case of rod 122 of FIGURE 1, rod 387 is capable of limited vertical motion.

The arrangement of rollers 385 and 386 in conjunction with slots 383 and 384 is such that when rod 387 is depressed, feeding devices 323 can move only if jaws 352 and 353 are disposed in either a horizontal plane or in a vertical plane. Since rod 387 is fastened to shaft 364, the tendency when rod 387 is depressed, is for the feeding mechanism to tilt over into the Vertical plane. To make certain that this action takes place, the inner surface of side plate 382 is provided with a baffle plate 388, which is so located as to contact end plate 356 of feed mechanism 323, if feed mechanism 323 starts to move in a horizontal position, and thereby, since baflie plate 388 is located behind slots 383 and 384, force feed mechanism 323 into the vertical position.

One of the pair of side plates 382 is provided with an upwardly extending rearward extension 389 to which isY rotatably journaled at 391 arm 392. Arm 392 is located so as to contact wheel 371 of lever extension 369 when feed mechanism 323 is in its upper position. By means of a cam operated mechanism, indicated by rodr393, arm 392 may be depressed at the proper point in the cycle of the machine to close jaw 353 towards jaw 352 of feed mechanism 323, so that lingers 357 and 360 will press against and retain any material contained there between. Rod 393 is actuated by a cam mechanism (not shown), having a cam attached to shaft 233 of FIGURE 8.

The cycle of operation of the feed device, starting at the portion in the cycle, wherein the feed device 323 is in its upper position with the jaws open and with feed conveyer 322 (FIGURE 13) -in its raised position, is first that a portion of material to be packaged, is fed to feed conveyer 322 and by means of feed conveyer 322 to the top of lower jaw 352. As the cycle of the machine progresses, feed conveyer 322 is rotatably retracted, arm 392 is depressed into contact with roller 371, thereby lowering and advancing upper jaw 353 and grasping the material to be packaged between the upper law 353 and lower jaw 352. Upper jaw 353 is then 1ocked into a closed positionL by the action of cam 372 and locking arm 373 and arm 392 is returned to its normal raised position. After the fold is formed in the packaging material (indicated at 207, FIGURE 14) arm 383 is depressed, thereby rotating feed device 323 into a vertical attitude and drawing the ends `of jaws 352 and 353 into the fold of wrapping material 287 as shown in FIGURE 14.

Support member 209 of the machine is provided with a trip arm 394 aflixed thereto, adapted to engage locking arm extension 375 of feed mechanism 323. Thus when feed mechanism 323, while disposed in a vertical attitude, nears the end of its downward motion, trip arm 394 engages locking arm extension 375, forcing locking arm extension 375 rearwardly, and thereby disengaging locking ystop 374 of locking arm 373 from the notch in cam 372. This permits the jaws to separate and t I6- 15 lease the material to be packaged into the fold. Wheel 381, of -end plate extension 379, is adapted to engage and ride against the side of baffle plate 388 as the jaws start to vopen and thereby limit the degree to which the jaws are capable of openingru'ntil the jaws are clear of the foldin film 207. After the material has been re-` leased in this way, feed mechanism 323 is permitted to return to its raised position by raising rod 383. When wheel 381 passes the upper edge of baffle plate 388 the jaws return to their fully open position and when roller 386 reaches the top of slot 384, feed mechanism 323 returns to its horizontal attitude, thereby completing the feed cycle.

It will be appreciated, of course, that other variations and modifications are possible without deviating from the inventive concept contained in the specific embodiments set forth in this specification.

I claim:

l. A wrapping machine, comprising in combination, a pair of pliers, means for periodically advancing a strip of wrapping material towards said pair of pliers, said pliers having means operable and arranged to catch and hold the foremost end of the strip, means for forming a transverse fold of the strip between the feeding means and the pliers, clamping members arranged to press together the two opposite open ends of the fold somewhat inside the longitudinal edges of the strip, cutting means for removing the fold from the rest of the strip, and means for sealing the three open ends of the fold outside said clamping members.

2. `A wrapping machine, comprising in combination, a pair of pliers, means for periodically advancing a strip of wrapping material towards said pair of pliers, said pliers having means operable and arranged to catch and hold the foremost end of the strip, a ruler extending transversely to the strip between said feeding means and said pliers and movable towards the ystrip in timed relation to and at half the speed of the strip to form a transverse fold, clamping members arranged to press together thek two opposite open ends of the fold somewhat inside the longitudinal edges of the strip, cutting means for removing the fold from the rest of the strip, and means for sealing the three open ends of the fold outside said clamping members.

3. A wrapping machine, comprising in combination, a pair of pliers, driving means, feed means for periodically advancing a strip of wrapping material towards said pair of pliers, said pair of pliers having meansY operable and arranged to catch and hold the foremost end of the strip, means for forming a transverse fold of the strip between the feeding means and the pliers of cam-operated mechanism, clutch means controlled by a said cam-operated mechanism to selectively connect said feeding means and folding means with said driving means during a selected period of time, said cam-operated mechanism having means adjustable for determining the depth of the fold, a plurality of clamping members arranged to press together two opposite open ends of the fold adjacent the longitudinal edges of the strip, cuttingr means for removing the fold from the rest of the strip, and means for simultaneously sealing three open ends of the fold outside said clamping members.

4. A wrapping machine, comprising in combination, a pair of pliers, means for periodically advancing a strip of wrapping material toward said pair of pliers, said pliers having means operable and arranged to catch and hold the foremost end of the strip, means for forming a transverse fold of the strip between the feeding means and the pliers, clamping members arranged to press to-

Images