US 3430414 A
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Description (OCR text may contain errors)
M r h 1969 w. e. LUDWIG ETAL 3,
MACHENE FOR PACKAGING ARTICLES IN A CONTROLLED ATMOSPHERE Filed Nov. 29, 1966 e 4; 1d,, MM VM? fla v dwwomon f March 4, 1969 w. 5. LUDWIG ETAL 3,430,414
FOR PACKAGING ARTICLES IN A CONTROLLED ATMOSPHERE MACHLNE Sheet FiledNov. 29, 1966 I l lllllll March 4, 1969 MACHLNB FOR PACKAGING ARTICLES IN A CONTROLLED ATMOSPHERE Sheet 3 Filed NOV. 29, 1966 W. G. LUDWIG ETAL 2m Qkfi/bvr 6.404% [Eda/d 0 230 701 a" March 4, 1969 w. LUDWIG ETAL MACHiNE FOR PACKAGING ARTICLES IN A CONTROLLED ATMOSPHERE Sheet 4 of 4 Filed Nov. 29. 1966 m B 0 flm m T 0 I. O w Z/T 0 sb T W M 0 lwm Q 7 o \l w Q 5 o m m 0 Z 0 m m 0 (w United States Patent 11 Claims This invention relates to a machine for packaging articles in a controlled or artificial atmosphere such as a vacuum and, more particularly, to a machine in which open ended bags are advanced through successive stations in which a product is inserted in each bag, the air in the bag is exhausted, and the open end of the bag is sealed.
The general object of the present invention is to exhaust air from the bags and seal the latter while they are advancing continuously and at a relatively high speed through the machine.
A more specific object is to provide novel mechanism for traveling with each bag through evacuating and sealing stations spaced apart along the path of the bags and, during such travel, first sealing the open end of the bag temporarily while the air is evacuated and then applying a permanent seal while maintaining the temporary seal.
Other objects and advantages of the invention will become apparent from the following detailed description taken in connection with the accompanying drawings, in which:
FIGURE 1 is a perspective view of a product which may be packaged in a controlled atmosphere by the present invention.
FIG. 2 is a schematic perspective view illustrating the various packaging steps performed by the illustrative machine.
FIG. 3 is an enlarged perspective view of a completed bag.
FIG. 4 is an enlarged fragmentary side elevational view of part of the machine, the view being taken at the evacuating station.
FIG. 5 is an enlarged cross-sectional view taken substantially along the line 5-5 of FIG. 4.
FIG. 6 is a fragmentary view of part of FIG. 4 with parts in moved positions.
FIG. 7 is a fragmentary plan view taken at the evacuating station.
FIG. 8 is an enlarged cross-sectional view taken through a bag at the evacuating station.
FIG. 9 is an enlarged cross-sectional view similar to FIG. 8 but taken at the sealing station.
As shown in the drawings for purposes of illustration, the invention is embodied in a machine for filling and closing bags 10 as the latter are advanced through filling and closing stations 11 and 12 spaced apart along the path followed by the packages through the machine. The representative bag comprises two sheets 14 and 15 of impervious flexible material such as polyethylene joined together along the lower edge of the bag by fold 17 and heat sealed together along the side margins at .18 to form the bag with an open upper end. Preferably, the side seals terminate short of the upper end to form a flap 19 (see FIG. 2) at the upper end of each sheet.
Various products may be packaged in such bags, for example, foods such as vegetables, fruit and the like which, when frozen, are solidified in the form of a shaped block 20 as shown in FIG. 1. After the product is deposited in each bag at the filling station 11, the two sheets are joined together along the upper end of the 3,430,414 Patented Mar. 4, 1969 bag, herein by heat sealing at 16, to complete the package at the sealing station 12.
As shown schematically in FIG. 2, the bags 10 are advanced through the machine in closely spaced edge-toedge relation by a carrier 22 (FIGS. 4 and 5) formed by a pair of endless chains 24 and 25 disposed in spaced horizontal planes. The forward runs of the chains are guided by tracks 26 and 28 (FIG. 5) and the return runs are guided by similar tracks 26' and 28' on the base, each track being formed by two elongated parallel bars having lower inwardly turned flanges terminating in spaced vertical faces 30 and 31 between which the chains slide. Both chains are driven in a conventional manner to advance the chains continuously and preferably at an even speed.
To support the bags 10' for movement with the chains 24 and 25, bag clamps 32 and 33 (see FIGS. 4-6) are spaced along the chains to grip the front and rear edges of each bag and hold the latter on the chains. Each pair of adjacent oppositely opening clamps is mounted on a clamp body 34 (Fl-G. 5) pinned to the under side of the upper chain and to the upper side of the lower chain, and each clamp comprises a pair of jaws disposed on opposite sides of the associated bag and resiliently urged together to grip the bag between them. Herein, one jaw of each clamp is disposed inside of or behind the bag and the other jaw 35 is a spring metal strip disposed in front of the bag and stressed toward the rear jaw. The clamp 33 gripping the trailing edge of each bag is carried on a generally upright finger 37 pivoted at 38 on the clamp body and having a lower portion 39 which extends downwardly to and then horizontally along a cam track 40 on the machine base. Each clamp 32 for the leading edge is mounted on an upright finger 41 that is pivoted at 42 on the clamp body and connected by linkage 43 to the adjacent trailing clamp 33. :It will be seen that up and down movement of the track 40 and the follower roller 44 carried on the trailing clamp will rock the latter about its pivot 38, and the connecting linkage transmits this rocking motion to the associated leading clamp so that the two clamps rock in unison but in opposite directions about their respective pivots. When the clamps holding a bag are rocked toward each other, the sheets of the bag are bowed away from each other to open the upper end of the bag. Reverse rocking closes the bag as the two clamps move apart.
To deposit the product in each bag 10 passing through the filling station .11, a conventional continuous motion filler mechanism is mounted on the machine base above the bag carrier at the filling station and includes a series of clamshell buckets 45 spaced apart along an endless carrier 47 shown schematically in FIG. 2 as a chain having a straight run overlying the portion of the bag carrier passing through the filling station. The chain is supported on two sprocket wheels 48, one being shown in FIG. 2, that are rotatable about vertical axes and driven in a conventional manner at the same speed as the bag carrier to advance the clamshells above the latter in alinement with a bag thereon. Along the return run of the carrier each bucket receives the product to be delivered to a bag, and, as the buckets move along the forward run, the usual duck-end mechanism (not shown) lowers the bucket into an alined bag, the clamp-rocking cam 40 having opened the bag to receive the bucket. Then the bucket is opened to release the product to fall into the bag and the bucket is withdrawn from the bag as the latter continues on. A splitter bar 49 holds the flaps 19 of the bags apart as they move on along their path.
For increased shelf life of some products, it is customary to evacuate the bags so that the product is packaged in a protective or artificial atmosphere. In accordance with the present invention, such evacuation is accomplished in a continuous motion packaging machine by a novel and relatively simple mechanism which travels with each bag while exhausting the air therefrom and then seals the top of the bag temporarily, holding the temporary seals until permanent seals have been applied in the sealing station 12. With such a mechanism, the bags may be evacuated and sealed while moving continuously and at high speed.
To accomplish the foregoing, an evacuating head 50 is mounted at an evacuating station 51 between the filling station 11 and the sealing station 12 and carries a series of nozzles 52 which are movable along the path of the bags in alinement with the latter and also are movable downwardly into the bags to draw the air therefrom. After a nozzle has been lowered into a bag, the upper end portion of the bag is clamped and sealed around the nozzle by a traveling sealer including a backing 53 and a resiliently compressible pad 54 supported for movement with each bag, in sealing engagement with the opposite sides thereof, from the evacuating station '51 to the sealing station 12. The temporary seal applied by the travel: ing sealer thus is maintained during evacuation of the bags, during withdrawal of the nozzles, and until the permanent seals have been applied.
In this instance, the nozzles 52 of the evacuating head 50 are supported on an endless carrier shown in FIGS. 2, 4 and and having a forward run or section which is disposed over a portion of the bag carrier 22 between the filling and sealing stations 11 and 12. Herein, the carrier is formed by a pair of vertically spaced chains 55 disposed in spaced horizontal planes and each trained around front and rear sprocket wheels 57 and 58 (see FIG. 2) which are mounted on vertical shafts 59 and 60 journaled in spaced plates 61 and 62 supported on the machine base, as shown in FIG. 5, on one side of the bag path. The chains are guided in tracks 63 formed by bars having opposed vertical surfaces 64 between which the chains slide, the guide bars for the upper chain being suspended below the upper support plate 62 and the guide bars for the lower chain being mounted on the upper side of the lower plate 61.
The evacuating nozzles 52 are flat, spade-shaped pieces sized to fit into the bags and formed with interior air passages 65 (FIGS. 7 and 8) opening downwardly through the lower ends of the nozzles toward the bags and also through the upper ends of the nozzles into fittings 67 (FIG. 5) supporting the nozzles on the under side of L-shaped blocks 68 each bolted at 69 to the upright slide plate 70. The slide plate is vertically slidable between two elongated upright bars 71 spaced apart and fastened at their upper and lower ends to the respective chains 55 of the nozzle carrier. The vertical position of each slide and nozzle relative to the supporting bars is controlled by a cam track 72 formed by the upper edge of a bar 73 disposed inside the path of the nozzle carriers to engage rollers 74 journaled on the rear sides of the slide plates. Herein, the cam bar 73 is mounted on two posts 75 extending between the support plates 61 and 62, and is formed in sections forming an endless track. The opposite ends of the front section of the track are inclined at 77 and 78 as shown in FIG. 4 to lower the nozzles into the associated bags as the nozzles move along the downwardly inclined section 77, hold the nozzles in the bags along the horizontal front section 79, and then raise the nozzles out of the bags as the follower rollers move along the upwardly inclined section 78. An overhead bar 80 holds the rollers in firm engagement with the downwardly inclined section. Along the return run of the nozzle carrier, the nozzles are held in raised positions on a rear section 81 as shown on the right in FIG. 5.
To apply the vacuum or suction to the nozzles 52, the interior passage 65 in each nozzle is connected through a valve 82 in the supporting piece 68 to a tube or conduit 83 extending upwardly through a clamp 84 to a flexible hose 85 connected at its upper end to a tube 87 on a manifold 88 rotatably supported above the nozzle carrier on a shaft 89 journ-aled on the plates 61 and 62 and rotated by a chain-and-sprocket connection 90 (FIGS. 2 and 4) with the carrier shaft 60. A main vacuum conduit 91 is connected to a stationary transfer cylinder 92 (FIG. 5) above the upper end of the shaft 89 and continuously communicates with manifold 88, through conventional transfer rings (not shown), thus applying suction to all of the conduits formed by the flexible hoses 85 and the tubes 83. By selection of the drive ratios, the speed of rotation of the shaft 89 is correlated with the speed of the nozzle carrier so that the manifold makes one revolution for each complete cycle of a nozzle, the hoses being long enough to accommodate all of the motion of the nozzles relative to the manifold.
The valves 82 through which the tubes 83 are connected to the nozzles 52 are operated to apply suction to the nozzles only after the latter have been inserted in the bags 10, and to cut off the vacuum as the nozzles are withdrawn. For this purpose, a rearwardly projecting operating lever 92 is pivoted on each L-shaped support on a pin 92 and extends rearwardly from the support through the space between the slide bars 71. A cam follower 93 on the free end of the lever is positioned to engage a rise 94 (see FIG. 4) on a cam bar 95 supported on the front post '75 and positioned to lift the follower when the associated nozzle has entered a bag. Lifting of the follower roller swings the lever upwardly to open the valve 82 and thus apply suction to the nozzle through the valve. The cam has a level surface 97 for holding the valve open as the nozzle travels with the bag, and also has a second rise 98 which follows the rise 78 on the cam 72 for the nozzle slide, thus maintaining the valve open as the nozzle is withdrawn from the bag. Upon leaving the cam bar, the follower rollers 93 are permitted to fall and thus close the vacuum valves which remain closed as the nozzles travel along the return run of the carrier and until they again reach the leading end of the cam bar. The exact moment of closing of the valves is determined by the position and shape of the cam.
The traveling sealer for pressing the side sheets 14 and 15 of each bag 10 tightly around the alined nozzle 52 during evacuation herein comprises a pair of identical endless carriers 99 (FIGS. 2 and 7-9) disposed on opposite sides of the bag path and having straight runs following the bag path from the evacuating station 51 through the heat sealing station 12, a resilient sealing pad- 54 being secured to the front carrier to travel with the bags along their paths, and a similar pad being secured to the rear carrier to form the movable backing 53. As shown most clearly in FIGS. 7-9, the carriers are two endless chains disposed side by side in a common horizontal plane and supported on two sets of sprocket wheels 100 (one sprocket of each set being shown in FIG. 5) spaced apart on opposite sides of the bag path so that the adjacent or forward runs of the chains are closely adjacent the bag path. These chains also are driven at the same speed as the bag carrier 22 to move the pads at the speed of the bags.
Spaced along the outer side of each chain 99 are a plurality of brackets 101 (FIGS. 7-9) which are connected to the links of the chains and carry holders 102 having outwardly facing semi-cylindrical recesses 103. Cylindrical bars 104 of resiliently flexible material such as rubber are cemented to the walls of the recesses to form the substantially continuous sealing pads 53 and 54 extending completely around each chain, each bar spanning several holders and having ends disposed close to the ends of the two adjacent bars on the chain.
It will be seen in FIGS. 2 and 5 that the front sprocket wheels 100 guide the sealing pads 53 and 54 into pressing engagement with each bag passing between the wheels, this occurring after a nozzle 52 has been inserted in the bag. The forward runs of the chains are spaced ap rt a distance substantially less than the combined thickness of the two sealing elements, including the parts 101 and 102 mounting the pads on the chains, and the pads thus are compressed along their adjacent sides to hold the two sheets of each bag firmly together ahead of and behind the nozzle as well as tightly against the sides of the nozzle, thereby positively sealing the open end of the bag around the nozzle and closing the open end of the bag against entry of outside air. As the nozzle is withdrawn from the bag after completion of the evacuation, the rubber pads spring toward each other to seal the bag before outside air can enter. Preferably, the suction to the nozzles is cut 05 only after the nozzle has been completely withdrawn.
The heat sealing mechanism shown schematically at the sealing station 12 (FIGS. 2 and 9) may be a well-known type such as that shown in Patent No. 3,230,687 in which opposed elongated seal bars 105 are maintained parallel to the bag path and moved along orbital paths carrying the heated opposed surfaces 107 (FIG. 9) of bars into engagement with opposite sides of a group of bags, then along the path in sealing engagement with the bags and at the same speed, and finally away from the bags and reversely along the path for another cycle. Reference is made to the aforesaid patent for details of construction and operation of such a sealer.
As shown in FIG. 9, the seal bars 107 herein are level with the flaps 19 of the bags 10 immediately below the upper ends thereof and above the temporary sealing pads 53 and 54 to apply the final seals above the temporary seals while the latter are maintained. The rear sprockets (not shown) of the temporary sealers are positioned far enough downstream to hold the pads in engagement with the bags until the heat seals are completed, preferably beyond the point where the heat seal bars move away from the bag path.
We claim as our invention:
1. In a machine for evacuating and sealing open-ended bags, the combination of, means for supporting a succession of the bags and advancing the same at a preselected speed continuously along a predetermined path through evacuating and sealing stations spaced along said path, a series of evacuating nozzles at said evacuating station, a carrier moving said nozzles at said preselected speed along an endless path and having a section overlying said bag path at said evacuating station, means lowering each nozzle into an alined bag passing through said station, holding the nozzle in the bag to evacuate the latter, and then raising the nozzle out of the bag before the nozzle leaves said section, a pair of endless sealer carriers having opposed runs on opposite sides of said path and extending from said evacuating station to said sealing station and moving at said preselected speed, resiliently compressible bars on said sealer carriers positioned to press against the opposite sides of each bag adjacent the open end after a nozzle has been inserted therein thereby to seal the open end around the nozzle and to hold the bag sealed during and after withdrawal of the nozzle, and means at said sealing station for traveling with each bag at said preselected speed and applying a heat seal adjacent said open end to seal the bag while the latter is pressed between said resilient bars.
2. The combination defined in claim 1 in which said nozzle carrier comprises at least one endless chain having a straight run forming said overlying section, said nozzles being supported on the chain by slides movable toward and away from the bag carrier to effect the lowering and raising motion of the nozzles.
3. The combination defined in claim 2 further including a rotary manifold mounted within said chain and driven at a speed correlated with the speed of said nozzles, and flexible conduits connecting said manifold to each nozzle to apply suction thereto while accommodating the raising and lowering motion 4. The combination defined in claim 2 further including a vacuum conduit and a valve movable with each nozzle, said valve being operable when open to establish communication between the nozzle and the conduit for evacuation of a bag, and operating means responsive to the position of each nozzle to open and close the valve in timed relation with the raising and lowering of the nozzle 5. The combination defined in claim 4 in which said operating means comprise an operator movable with the nozzle along its path, and a stationary cam positioned along said path to engage the operator and open the valve after the nozzle has been inserted and to close the valve after the bag has been evacuated.
6. The combination defined in claim 1 in which said sealer carriers are endless chains having mounting brackets spaced along the outwardly facing sides thereof, said bars being carried on said brackets and forming a substantially continuous compressible pad extending around each chain.
7. The combination defined in claim 1 in which said heat sealing means includes two elongated heat sealers disposed on opposite sides of said bag path and engageable with opposite sides of the bags between said bars and the upper ends of the bags.
8. In a machine for packaging a product in flexible bags, the combination of, a carrier for supporting a succession of bags having open ends and advancing the bags along a predetermined path through spaced evacuating and sealing stations, a second endless carrier having a run extending along said bag path at said evacuating station, a plurality of nozzles spaced apart along said second carrier to move through said evacuating station in alinement with the bags on said bag carrier and supported for movement downwardly into the alined bag as the latter moves through said evacuating station, a backing extending along one side of said path from said evacuating station to said sealing station, a third endless carrier overlapping said second carrier longitudinally of said path and having a run extending along the other side of said path from said evacuating station to said sealing station, a resiliently compressible element on said third carrier traveling with and pressing against the open end portions of said bags to close the same around said nozzles and against said backing, said element moving away from said path and said bags beyond said sealing station, means for evacuating said bags through said nozzles while the latter are lowered into the bags, means for withdrawing each nozzle from the alined bag and from between said element and said Ibacking whereby said element thereafter presses each open end portion against said backing, and means at said sealing station for sealing said open ends before said resilient element moves away from said path.
9. In a machine for evacuating and sealing open-ended bags, the combination of, means for supporting a succession of the bags and advancing the same along a predetermined path through evacuating and sealing stations spaced along said path, a series of evacuating nozzles at said evacuating station, a carrier supporting said nozzles for movement along said path with each nozzle alined with the open end of a bag, means for shifting each nozzle into a bag at said evacuating station and subsequently withdrawing the nozzle, a temporary sealer including a backing on one side of the bag path and resiliently compressible sealing pad on the other side, means supporting said backing and said pad for movement into sealing engagement with the open end portion of each bag after a nozzle has been inserted therein and for movement with each bag to said sealing station thereby to close the bag around the nozzle during evacuation and to maintain the vacuum during and after withdrawal of the nozzle, and means at said sealing station for applying permanent seals to each bag while the latter is held between said backing and said pad.
7 10. The combination defined in claim 9 in which said backing also is resiliently compressible.
11. The combination defined in claim 10 in which said backing and said pad are substantially continuous elements supported on endless carriers disposed on opposite sides of 5 the bag path with opposed runs extending from said evacuating station through said sealing station and spaced apart a distance less than the combined width of the elements whereby the latter are yieldably pressed against the opposite sides of each bag.
8 References Cited UNITED STATES PATENTS 3,230,687 1/1966 Nutting et a1 53-28 2,410,834 11/1946 Mess-met 53-112 TRAVIS s. MCGEHEE, Primary Examiner.
H. M. CULVER, Assistant Examiner.
US. Cl. X.R. 53112