US3619975A - Machine for packaging product in a controlled atmosphere - Google Patents

Abstract

POUCHES ADVANCED ALONG A HORIZONTAL PATH BY A PACKAGING MACHINE ARE OPENED, FILLED SEALED WHILE BENEATH A HOOD OF COMPARATIVELY SMALL VOLUME TO WHICH NITROGEN IS SUPPLIED TO EXCLUDE THE OUTSIDE ATMOSPHERE FROM THE POUCHES AND THE PRODUCT DEPOSITED THEREIN. THE HOOD ENCLOSES ONLY THE UPPER ENDS OF THE POUCHES TO LEAVE THE

LATTER AND VARIOUS MECHANISMS FOR OPERATING ON THE POUCHES ACESSIBLE TO THE OPERATOR OF THE MACHINE.

Description

Nov 16, 1971 K. R. JOHNSON ETAL Filed May 25, 1970 4 SheetsSheet 1 Nov. 16, 1971 K. R. JOHNSON ETA!- Filed May 25, 1970 MACHINE FOR PACKAGING PRODUCT IN A CONTROLLED ATMOSPHERE 4 Sheets-Sheet 5 A; :l l/ I I f\\ \E I] I I! 1 I 1' l I I I f; x7 a 11 1/ f i \1' i I A. I -22,

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NOV. 16, 1971 JOHNSON EI'AL 3,619,915

MACHINE FOR PACKAGING PRODUCT IN A CONTROLLED ATMOSPHERE Filed May 25.

4 Sheets-Sheet 4.

'UnitedStates Patent O 3,619,975 MACHINE FOR PACKAGING PRODUCT IN A CONTROLLED ATMOSPHERE Kenneth R. Johnson, W. Gerald Tyson, and Joe F. Soroka,

Rockford, Ill., assignors to Riegel Paper Corporation,

New York, N.Y.

Filed May 25, 1970, Ser. No. 40,250 Int. Cl. 1565b 31/06 U.S. Cl. 53-112 B 10 Claims ABSTRACT OF THE DISCLOSURE Pouches advanced along a horizontal path by a packaging machine are opened, filled and sealed while beneath a hood of comparatively small volume to which nitrogen is supplied to exclude the outside atmosphere from the pouches and the product deposited therein. The hood encloses only the upper ends of the pouches to leave the latter and various mechanisms for operating on the pouches accessible to the operator of the machine.

BACKGROUND OF THE INVENTION This invention relates to a machine for packaging product in flexible walled pouches in the presence of an inert or non-oxidizing gas so as to maintain the product in a substantially oxygen-free environment within the pouches. The invention has specific reference to a machine in which initially flat pouches are opened, filled and sealed in a controlled atmosphere as the pouches are advanced edgewise along a predetermined path past various mechanisms for operating on the pouches. A machine of this general type is disclosed in Bartelt US. Pat. 2,649,671 and includes a housing which encloses the pouch operating mechanisms and into which a non-oxidizing gas is introduced to maintain the controlled atmosphere.

SUMMARY OF THE INVENTION The general aim of the present invention is to provide a new and improved packaging machine of the above character which, as compared to prior machines of the same general type, is simpler and less expensive in construction, requires smaller quantities of gas to maintain a controlled atmosphere around and within the pouches and, at the same time, afiords greater and more convenient access to the pouches and the pouch operating mechanisms for purposes of servicing the machine and correcting malfunctions.

A more detailed object is to achieve the foregoing through the provision of a machine with a novel hood which maintains a controlled atmosphere around the open ends of the pouches while leaving the sides of the pouches and essentially all of the working elements of the pouch operating mechanisms exposed and readily accessible to the operator of the machine. The hood is of comparatively small volume and thus requires only a relatively small amount of gas to maintain the controlled atmosphere.

The invention also resides in the novel construction of the hood and in the unique coaction between the hood and certain ones of the operating mechanisms to effect filling and sealing of the pouches while keeping the pouches substantially free of oxygen.

Other objects and advantages of the invention will become apparent from the following detailed description when taken in connection with the accompanying drawmgs.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary perspective view of a new and improved packaging machine embodying the novel features of the present invention.

Patented Nov. 16, 1971 FIG. 2 is an enlarged plan view of the hood of the machine illustrated in FIG. 1 and schematically showing the gas supply system for the hood.

FIG. 3 is an enlarged fragmentary cross-section taken substantially along the line 33 of FIG. 2.

FIGS. 4 and 5 are enlarged fragmentary cross-sections taken substantially along the lines 44 and 55, respectively, of FIG. 3.

FIG. 6 is a cross-section taken substantially along the line 66 of FIG. 5.

FIGS. 7 and 8 are enlarged fragmentary cross-sections taken substantially along the lines 7-7 and 88, respectively, of FIG. 3.

FIG. 9 is a view similar to FIG. 5 but showing a modifled product dispenser for the machine.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in the drawings for purposes of illustration, the invention is embodied in a packaging machine for filling flexible walled pouches 10 of heat scalable material with product and for sealing the pouches to enclose the product therein. The basic machine is of the same general type disclosed in the aforementioned Bartelt patent and includes a movable chain-type conveyor 11 (shown schematically in FIG. 1) mounted on a main frame 13 and carrying clamps 14 which grip the pouches and advance the latter edgewise and open end up along a horizontal path through various operating stations located at horizontally spaced positions along the path.

Each set of clamps 14 initially picks up the leading pouch 10 of a strip of interconnected and newly formed pouches advanced toward the upstream end of the conveyor 11 by feed rolls 15 (FIG. 1), and grips the leading pouch as the latter is severed from the strip by a cutting mechanism 16. The conveyor, the feed rolls and the cutting mechanism herein are driven intermittently and in timed relation by a power-actuated cycle shaft 17 extending beneath the frame 13. The pouches thus are advanced by the conveyor with a step-by-step motion and are filled and sealed at spaced filling and sealing stations 19 and 20 (FIGS. 1 and 3) during the dwell periods which occur between successive steps.

In the packaging of certain products, and particularly food products such as coffee, it is desirable to fill and seal the pouches 10 in the presence of a protective atmosphere so that the packaged products will be maintained in a substantially oxygen-free environment to help preserve the original freshness and flavor of the products. The protective atmosphere is established by flowing a nonoxidizing gas such as nitrogen or carbon dioxide in and around the pouches as the latter are filled and sealed thereby to purge the pouches of oxygen and to prevent the admission of oxygen into the pouches.

In accordance with the primary aspect of the present invention, the non-oxidizing gas is introduced into a novel and comparatively simple and inexpensive hood 21 which extends through the operating stations and confines the gas around the upper ends of the pouches during filling and sealing while leaving the sides of pouches and the pouch operating mechanisms completely exposed for easy access by the operator'of the machine to facilitate servicing of the machine. The hood, as a result of enclosing only the upper ends of the pouches, defines a gas chamber of relatively small volume and thus less gas is required to fill the hood and establish the protective atmosphere than has been the case with previous machines of the same general type.

In this instance, the hood 21 extends along the path of the pouches 10 from a point just upstream of the filling station :19 to a point just downstream of the sealing station 20 through a distance of about twenty inches and herein comprises a metal tube of rectangular cross-section with a width just slightly over two inches, the hood being supported by horizontal brackets 23 (FIG. 1) fastened to upright posts 24 upstanding from the frame 13. The hood includes a horizontal top wall 25 (FIG. 8) spaced above the upper ends of the pouches, depending side walls 26 disposed on opposite sides of the pouches, and a bottom 27 formed with a longitudinal passage or slot 29 approximately of an inch in width for receiving the upper ends of the pouches as the latter are advanced from the filling station to the sealing station. For a purpose to be described subsequently, an upstream section 21a (FIG. 3) of the hood extending from the filling station to just ahead of the sealing station is constructed just slightly differently than a downstream section 2117 of the hood actually extending through the sealing station. Thus, the upstream hood section 2111 is of a depth of approximately one inch with the bottom 27 thereof spaced about A of an inch below the upper edges of the pouches while the downstream hood section 211) is of a depth of only about Vs of an inch with its bottom spaced slightly above the bottom of the upstream section. Accordingly, the upper ends of the pouches project further upwardly into the hood while advancing through the filling station than during their advance through the sealing station.

Non-oxidizing gas, preferably nitrogen, is delivered to the hood 21 from a supply cylinder 30 (FIG. 3) through a line 31 under the control of pressure regulating valves 33 and 34. Part of the gas flowing through the valve 34 is directed into a manifold 35 (FIG. extending along one of the side walls 26 of the upstream hood section 21a and flows laterally into the hood through a series of holes 36 formed in the manifold and the side wall. The remainder of the gas from the valve 34 is diverted to a manifold 37 (FIG. 8) extending along the top wall 25 of the downstream hood section 21b and is directed downwardly into the hood through holes 39 spaced along the manifold and the top wall. When filling pouches with a 1.3 ounce capacity, approximately 0.1 cubic feet of gas per minute is admitted into the hood.

Before being advanced beneath the hood 21 and filled, the initially fiat pouches are pro-opened and are purged with nitrogen. For these purposes, a splitter bar 40 (FIGS. 1, 3 and 4) is positioned upstream of the hood and extends along the pouch path so as to be straddled by the upper edge portions of the pouches as the latter are picked up and advanced by the clamps 114. The splitter thus keeps the upper edges of the side panels of the pouches separated from one another. Formed in the splitter and opening out of the lower edge thereof is an upright passage 41 (FIG. 4) which communicates with the nitrogen cylinder 30 through a line 43 and the valve 33. As each pouch dwells beneath the passage, a shot of nitrogen at a pressure of about 8 to 10 psi is blown into the pouch to separate the side panels as shown in FIG. 4. Rubber pressure pads 44 disposed on opposite sides of the splitter seal the upper edge portions of the pouch against the splitter to enable the nitrogen to expand the side panels. In addition, retainer paddles 45 are positioned opposite the side panels to control the extent of opening of the pouches. The pads and the paddles are carried on generally upright rods 46 pivoted on the frame '13 and are swung toward each pouch as the latter dwells and then are retracted to leave the pouch free to advance. Swinging of the rods is effected by a cam fast on the cycle shaft 17 and operably connected to the lower ends of the rods.

After being blown into a partially opened condition, each pouch 10 is advanced beneath the hood 21 and into the filling station 19, the upper edge portions of the pouch moving into the slot 29 in the bottom 27 of the hood. Before being filled, the pouch is opened widely by pouch openers comprising suction cups 49 (FIG. 5) disposed on opposite sides of the pouch. Herein, two cups are located on each side of the pouch and are positioned to engage the pouch just below the hood. Each pair of cups is carried on a swingable rod 50 (FIG. 1) pivoted on the frame and communicates with a vacuum source (not shown) through a conduit 51. As the pouch dwells in the filling station, the rods are swung inwardly to place the cups in engagement with the sides of the pouch and, at the same time, vacuum is applied to the cups to cause the latter to grip the pouch. Thereafter, the rods are swung outwardly such that the cups pull the pouch into a widely open condition as shown in FIG. 5. To enable the upper end of the pouch to open widely, an intermediate portion of the slot 29 extending through the filling station 19 is enlarged to form a diamond-shaped opening 54 in the bottom 27 of the hood as shown in FIGS. 2 and 5, the opening 54 also serving to control somewhat the width and the contour to which the upper end of the pouch is opened.

Because of the hood 21, a continuous flow of nitrogen is maintained above each pouch 10 as the latter is opened by the cups 49 so as to restrict the admission of oxygen into the pouch. Also, because the hood encloses only the upper ends of the pouches and because the cups are positioned below the hood, the cups are easily accessible for servicing or adjustment.

Just after each pouch 10 has been opened by the cups 49, a measured charge of product, herein coffee, is deposited into the pouch by a dispenser which comprises a hopper 55 (FIG. 1) disposed in the filling station 19 and a conical collector 56 located beneath the hopper. The collector includes a spout 57 (FIGS. 3 and 5) which projects into the top wall 25 of the hood 21 through an opening therein and terminates just short of the pouch. The areas of the opening around the spout are closed by a plate 59 (FIG. 3) fastened releasably to the top wall 25.

In many processing plants, the coffee, after being roasted and ground, is delivered to the hopper 55 in a substantially oxygen-free condition. As each pouch dwells in the filling station, a measured amount of coffee passes from the hopper into the collector through an outlet tube 60 (FIG. 5) extending through a cover plate 61 on the collector. To prevent the outside atmosphere from entering the collector, nitrogen is admitted continuously into the collector at a rate of about one cubic foot per minute through a series of angularly spaced orifices 63 (FIGS. 5 and 6) formed in the cover plate 61 and communicating with a supply line 64 by Way of an annular groove 65 cut in the plate.

The coffee passing through the outlet tube 60 of the hopper 55 falls into a dish 66 (FIG. 5) located near the upper end of the collector 56 and secured to a powerrotated shaft 67 such that the coffee is thrown outwardly from the dish and into the collector by centrifugal force and drops through the spout 57 into the pouch 10 in the filling station 19. As shown in FIGS. 3 and 5, a second splitter 69 extends from the filling station to just short of the sealing station 20 and includes a narrow finger 70 which underlies the spout to divert the coffee toward the side panels of the pouch and thereby promote uniform filling of the pouch. Because filling of the pouch takes place under the nitrogen-filled hood 21, there is very little chance for the outside atmosphere to enter the pouch or to mix with the coffee during filling.

Before being sealed, each filled pouch 10 is purged completely with nitrogen which is directed upwardly from the bottom of the pouch to the top of the pouch to drive out any oxygen that possibly might be in the pouch. For this purpose, each filled pouch is advanced to a purging station 71 (FIG. 3) located between the filling and sealing stations 19 and 20. Disposed in the purging station is a rectangular snorkel tube 73 which extends downwardly through the hood 21 through a sealed opening 741 in the top wall 25, an opening 75 in the splitter 69', and the slot 29 in the bottom 27 of the hood. As each pouch dwells in the purging station, the snorkel 73 is shifted downwardly from a raised position (FIG. 3) above the pouch to a lowered position (FIG. 7) in which the lower end of the snorkel is located adjacent the bottom of the pouch. As the snorkel reaches its lowered position, pressure pads 76 (FIG. 7) mounted on pivoted rods 77 (FIG. 1) are swung into engagement with the pouch to hold the upper end portions of the pouch in a semi-closed condition. Nitrogen is admitted continuously into the snorkel at a rate of. about 0.3 cubic feet per minute and flows upwardly through the pouch to drive out any oxygen and to leave the pouch filled with nitrogen. The snorkel thereafter is raised out of the pouch to free the latter for advancement to the sealing station 20. Raising and lowering of the snorkel are effected by a lever 80' (FIG. 1) which is rocked upwardly and downwardly by a linkage 81 actuated by the cycle shaft 17 and which shifts a slide 83 upwardly and downwardly on the frame 13, the snorkel 73 being carried by and movable with the slide.

Each pouch 10, after being purged, is advanced to the sealing station 20 where a pair of heated sealing bars 84 (FIG. 8) carried on the rods 77 are swung into engagement with the upper end portions of the pouch to seal the latter closed. During sealing, nitrogen flows directly downwardly into the hood 21 and toward the upper end of the pouch through the openings 39 and thus prevents the outside atmosphere from entering the pouch. Because the bottom 27 of the hood section 21b extending through the sealing station is offset upwardly from the bottom of the upstream hood section 21a, the seal bars 84 may be located very close to the extreme upper edge portions of the pouch while still keeping the upper edge portions disposed within the slot 29 and protected from the outside atmosphere.

From the foregoing, it will be apparent that the present invention brings to the art a new and improved machine in which the hood 21 encloses only the upper end portions of the pouches so that the various operating mechanisms such as the pouch opening cups 49 and the seal bars 84 are exposed for servicing and adjustment. Also, the operator of the machine can easily reach and clear pouches from the conveyor 11 should a malfunction occur to cause jamming of the machine. The hood is of comparatively low cost construction and can be incorporated on existing packaging machines with little difficulty. Because the hood defines a chamber of only relatively small volume, a suitable pressure head can be maintained in the hood with a comparatively low rate of nitrogen flow and yet pouches of the type described and packaged with coffee delivered to the machine in a substantially oxygen-free condition have been run consistently with an oxygen content within the low range of one-half to one percent.

'In certain instances, the coffee is not protected within the processing plant and is delivered to the packaging machine with a high oxygen content. Under such circumstances, the machine is equipped with a modified collector 56' (FIG. 9) into which nitrogen is admitted to drive the oxygen from the coffee before the coffee is packaged. As shown in FIG. 9, vertically spaced rows of angularly spaced and upwardly directed openings 90 are formed around the conical wall of the collector '56 and communicate with a manifold 91 to which nitrogen is supplied through a line 93 at a rate of about three cubic feet per minute. Much of the nitrogen admitted into the collector flows upwardly through the downwardly falling coffee and drives the oxygen out of the coffee and the collector through an outlet 94 communicating with the cover plate 61' of the collector. By using the collector 56' in conjunction with the hood 21, coffee which has been previously exposed to the atmosphere has been packaged with an oxygen content within a range of from one to two percent.

We claim:

1. In a machine for filling flexible pouches with product in a controlled atmosphere, the combination of, mechanism for advancing the pouches open end up and in spaced edgewise relation along a generally horizontal path through spaced filling, purging and sealing stations, a hood extending along said path between said stations, said hood having a top overlying the upper ends of said pouches and having laterally spaced side walls depending from said top on opposite sides of the pouches and terminating just below the upper ends of the pouches whereby said upper ends project upwardly into said hood as the pouches are advanced along said path, a dispenser in said filling station and having a spout projecting through the top of said hood to deposit product into the pouches, pouch openers disposed in said filling station and having means located below the hood for engaging the sides of pouches in said filling station to open the pouches widely prior to filling, a purging tube extending through the top of said hood and insertable into pouches in said purging station to introduce a non-oxidizing gas into such pouches, a sealing unit disposed below said hood in said sealing station and operable to seal the upper ends of pouches in the sealing station, and means for flowing a nonoxidizing gas into said hood to maintain a substantially oxygen-free atmosphere in said pouches as they are advanced along said path and are opened, filled and sealed.

2. A machine as defined in claim 1 in which said hood includes a bottom wall connected to said side walls and formed with a passage extending along said path and receiving the upper ends of said pouches as the latter are advanced.

3. A machine as defined in claim 2 in which the width of the passage through the purging and sealing stations is just slightly greater than the thickness of the pouches, the passage being enlarged in said filling station to accommodate the upper ends of the pouches as the latter are opened.

4. A machine as defined in claim 2 in which the section of the bottom wall extending through said sealing station is spaced upwardly from the section of the bottom wall extending through said filling station to enable said sealing unit to engage said pouches immediately adjacent the upper ends thereof.

5. A machine as defined in claim 1 in which said purging tube is slidable upwardly and downwardly within said hood between an upper position in which the lower end of the tube is adjacent the upper ends of the pouches and a lowered position in which the lower end of the tube is adjacent the bottoms of the pouches, and means for moving said tube between said positions in timed relation with the advance of the pouches.

6. A machine as defined in claim 1 further including means for directing an inert gas into said dispenser.

7. A machine as defined. in claim 6 in which said directing means include a series of holes spaced angularly around the top of said dispenser whereby the inert gas is directed downwardly into the dispenser and precludes the entry of the outside atmosphere into the dispenser.

8. A machine as defined in claim 6 in which said directing means include vertically spaced rows of angularly spaced and upwardly directed holes in the side walls of the dispenser whereby the inert gas is directed radially and upwardly into the dispenser, and further including an outlet in the top of the dispenser to enable the gas to flow out of the dispenser.

9. A machine as defined in claim 1 further including a splitter positioned upstream of said filling station and located to be straddled by the upper ends of the pouches so as to hold said upper ends spread apart, and a flow passage incorporated in said splitter for injecting a charge of inert gas into the pouches to purge and expand the pouches prior to the pouches being opened and filled.

10. In a machine for filling flexible pouches with product in a controlled atmospher, the combination of, mechanism for advancing the pouches open end up and in spaced edgewise relation along a predetermined path through horizontally spaced filling and sealing stations, a hood extending along said path between said stations,

7 said hood having a top overlying the upper ends of said pouches, having laterally spaced side walls depending from said top on opposite sides of the pouches, and having a bottom with a passage therein extending along said path and alined with the upper ends of the pouches, the upper ends of said pouches projecting into said hood through said passage in said filling station and at least registering with said passage in said sealing station, a dispenser in said filling station and having a spout projecting through the top of said hood to depoist product into the pouches, means located along said path and operable to open the pouches widely prior to filling, a sealing unit disposed below said hood in said sealing station and operable to seal the upper ends of the pouches in the sealing station, and means for flowing a non-oxiding gas References Cited UNITED STATES PATENTS 5/1965 Canfield 53112 B 4/1969 Poss et a1. 53ll0 TRAVIS S. MCGEHEE, Primary Examiner US. Cl. X.R. 53l 10

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