US3397506A

US3397506A - Apparatus for packaging

Info

Publication number: US3397506A
Application number: US499896A
Authority: US
Inventors: Jr Grant E Allen; Jr Glen P Robinson; Richard B Inman
Original assignee: Scientific Atlanta LLC
Current assignee: Scientific Atlanta LLC
Priority date: 1965-10-21
Filing date: 1965-10-21
Publication date: 1968-08-20
Anticipated expiration: 1985-08-20
Also published as: GB1092959A

Description

Aug. 20, 1968 G. E. ALLEN, JR, ET AL 3,397,506

APPARATUS FOR PACKAG ING 5 Sheets-Sheet 2 Filed Oct. 21 1965 L/MAM,M

ATTO RNEYJ Aug. 20, 1968 G N, JR ET AL 3,397,506

APPARATUS FOR PACKAGING Filed Oct. 21, 1965 5 sheets sheet 3 INVENTORS I 3. Gee/v7- Z /94/V, 12.

GAE/Y 7 Faamasamde. Y fi/c/mw fi fly/v0 ZW, Mug, 7:34AM

ATTORNEYS Aug. 20, 1968 Filed Oct. 21. 1965 G. E. ALLEN, JR.

ET AL APPARATUS FOR PACKAG ING SSheets-Sheet 4 G'Rmvr Z. 445, dd.

.4 1v Rea/050M, .Ae Flax/map B.//Y/m9/v ATTORNEYS Aug. 20, 1968 ,G. E. ALLEN, JR, ET AL APPARATUS FOR PACKAG ING 5 Sheets-Sheet 5 Filed Oct. 21, 1965 INVENTORS 6 am),- Zf'flzz E/V, JR. 6'45 7 Fae/Asa BYF/c A69! .5. [IV/V194 M 9' M v ATTORNEYS United States Patent ABSTRACT OF THE DISCLOSURE Apparatus for flushing a package with a gas other than air and closing the package. The apparatus is adapted for use with a cup, preferably semi-rigid plastic, having walls and a bottom with a flange extending outwardly from the top of the walls. A lid rests on the flange at opposite sides of the package and is bowed upwardly over the center of the package to provide a kind of tunnel for air and gas flow. The apparatus includes a suction inlet and an outlet for the replacement gas, positioned adjacent opposite sides of the package. The package is moved between these and gas flows through the aforesaid tunnel. Then the package moves to another station where the lid is sealed against the flange.

The present invention relates to packaging and more particularly to an apparatus and a method for the packaging in containers, such as rigid, transparent or translucent plastic, of products including sliced luncheon meat and other perishable goods. The invention embraces a novel apparatus which is an improvement of the apparatus described in the U.S. patent application of Richard Inman, Ser. No. 398,721 filed Sept. 23, 1964, and includes a conveyor, means for replacing air in the packages with another gas and means for sealing it while the package is advanced by the conveyor.

As explained in the Inman application, there has been a need for an inexpensive package for sliced luncheon meat and the like which has a rigid transparent plastic compartment or cup and a lid to hermetically seal the opening of the cup. Such a package is described in the US. patent application of Harmon B. Miller, Ser. No. 384,846, filed July 24, 1964. The aforesaid Inman application describes apparatus and a method for replacing air in the package with another gas such as an inert gas and closing the package with a hermetically sealed bid. Typically, the gas may be carbon dioxide. In that apparatus the package, having an unsealed lid over it, is moved by a conveyor from a vacuum chamber, past a membrane, to a chamber containing another gas, and the gas thereby is swept through the package as it passes the membrane.

It has been found in practice that the speed of operating that apparatus is limited by the need for relatively high efiiciency of gas flushing. That is, in a preferred form of that apparatus, a package is moved step-wise from a filling station, to the vacuum chamber and then to the gas chamber. As the speed of the apparatus is increased, the time during which gas is swept through the package is decreased; therefore the speed of the apparatus is limited.

In accordance with the present invention, gas is swept through the package while it is stationary in a chamber. The conveyor conveniently will be stationary for a reasonably long interval while completed packages are ejected and unclosed packages are inserted and this provides suffieient time for flushing the package without restricting its speed when the packages are in motion. Therefore, the above-described delay is not experienced it the flushing is carried out then.

The flushing operation is accomplished by bowing the lid upwardly over the package to form a kind of tunnel and providing a pressure differential between the ends of the package. In the preferred form of the apparatus, the package is carried within a moving table, and gas and vacuum are provided by tubes which open downwardly toward the table adjacent the ends of the package.

The apparatus and its mode of operation will be better understood from the following detailed description of a preferred embodiment thereof, and by reference to the drawings, in which:

FIG. 1 is a perspective view of the apparatus;

FIG. 2 is a perspective view of the portion of the apparatus in which gas flushing takes place;

FIG. 3 is a side elevation, partially in section, of the apparatus of FIG. 1, with some parts removed for simplicity;

FIG. 4 is a rear elevation of the lower portion of the apparatus;

FIG. 5 is an elevation, partly in section, of the lower portion of the other side of the apparatus; and

FIG. 6 is a plan view of the apparatus.

For convenience of description, the apparatus may be considered to be subdivided into a rotating table 1 which carries the packages, a flushing chamber 2, a label dispenser 3, a package closing chamber 4, a heat sealing press 5, and the drive mechanisms indicated generally at 6 which are beneath the rotating table 1.

The table 1 is a closed end hollow cylinder mounted for rotation about a vertical axis. There are six openings 7 in the top of the table to receive packages and there is a basket 8 under each of the openings to provide a relatively air-tight cavity around the packages. There is an opening 9 in the bottom of each basket and a piston 10 is slidably mounted therein for vertical movement. The top 11 of the piston is relatively wide and ejects a package when the piston is raised by a cam under the table.

At the edge of each opening 7, there is a recessed ledge 12, which receives a mandrel 13. The mandrel has a central opening 14, the edge of which is recessed to provide a ledge 15, the shape of which is shown best in FIG. 2. The dimensions of the ledge are slightly larger than those of the cup which is to be inserted in it. Several mandrels may be supplied with the apparatus, having central openings which accept various sizes and shapes of packages, thereby permitting easy conversion from one packaging operation to another.

The gas flushing chamber 2, best seen in FIG. 2 is preferably constructed of transparent plastic, permitting observation of the flushing step. It comprises sides 16 and a top 17. A gasket is provided under the sides which makes a relatively gas-tight seal with the top of the rotating table 1.

At the radially inner and outer ends of the top, there are threaded openings in which are inserted

elbow tubing connectors

18 and 19. These are attached to

tubes

20 and 21 which lead to vacuum and gas sources.

The label dispenser 3 is at one side of the rotating table 1 and includes .a hopper 22 mounted directly over the path of the packages. The hopper is slightly more narrow than the labels so that they are maintained in a slightly bowed condition. Interchangeable hoppers may be supplied with the apparatus to permit easy adaptation to several sizes of packages.

Labels are dispensed by a moving arm 23 which extends radially inwardly over the table. The arm 23 carries two rubber suction cups 24 and 24' and means are provided for alternately supplying vacuum and air under pressure through a tube in the arm to openings within the suction cups. In operation, the arm is raised with the suction cups turned upwardly, until they touch the bottom of the labels in the hopper 22. Suction is applied and the arm is lowered, withdrawing the bottom label. The arm is rotated 180 as it moves downwardly to invert the label, and places the label on a package in a mandrel 13 at the bottom of its stroke. At that point, the arm actuates a microswitch (not shown) which operates a valve disconmeeting the suction and introducing air under pressure to the suction cups. This causes the labels to drop quickly onto a package.

The package closing chamber 4 is spaced 60 from the gas flushing chamber and comprises sides 25 and a top 26 suspended from a crank housing 27 and resting on the rotating table 1. A gasket 28 is under the sides to provide a relatively gas-tight seal to the rotating table 1. The radially inward side is removable, being held in place by quick detach devices, permitting access to a heat sealing mechanism and removal of a package in case of malfunction.

Between the gas flushing chamber 2 and the package closing chamber 4 there is a low chamber 4'. This is a casting having a top and sides, the sides resting on a gasket, which makes a relatively gas-tight seal with the table. The chamber 4 is attached at one end to the package closing chamber 4 and at the other end carries clips which hold the sides 16 of the gas flushing chamber against it. It prevents unnecessary escape of the gas as the package is moved from the gas flushing chamber to the package closing chamber.

The package is closed by the heat sealing press which includes an electrical heater 29 and an easily interchangeable heating platen 30 depending from and in contact with the heater. The platen includes a downwardly extending member having the shape of the outer edges of the pack age to apply heat and pressure to the edge portion only of the lid, thereby heat sealing the lid to the package without excessive heating of its contents. The electrical heater is at the bottom of a plunger 31 which is mounted for vertical sliding movement in a compartment 32 at the inner end of the crank housing 27. The plunger carries a laterally-extending pin 33 on which is mounted a ball bearing which engages in a slot in the inner end of the bell crank 34, the bell crank being pivotally mounted in the outer end of the crank housing. Vertical movement of the plunger is accomplished by inward and outward movement of the lower extremity of the bell crank, by means to be described further herein.

As a package leaves the package closing chamber 4, it indexes to the next station where it is raised by the piston and ejected. A piston is maintained elevated at the ejection station and then an arm 35 sweeps across, propelling the package outwardly onto a downwardly inclined conveyor 36. The piston is lowered as the table indexes to its next position.

The drive mechanisms are in a housing beneath the table 1. All power for the above-described mechanical movements is provided by an electric motor 37. A clutchbrake mechanism 38 is connected to the shaft of the motor which alternately supplies motion to and brakes the moving parts. That is, when motion is to be supplied, the clutch, which is connected to the motor shaft, is engaged and the brake, which is connected to an output drive shaft 39, seen in FIG. 4, is disengaged. To stop motion, the clutch is disengaged, and, substantially simultaneously, the brake is engaged.

A pulley 40 is mounted on the output drive shaft 39, connected by a belt to another pulley 41 on an input shaft 42 of a reduction gear set 43. The output of the reduction gear set is an upwardly-extending vertical shaft 44 on which are mounted a sprocket wheel 45 and a cam 46.

The cam 46 operates the bell crank 34, by means of a horizontal crank arm 47 to reciprocate the heating platen 30. One end of the crank arm is pivotally mounted on the housing of the drive mechanism 6, and the other end is pivotally mounted on a link 48 which in turn is pivotally connected to the bottom of the bell crank 34. At the center of the crank arm, there is a depending bearing 49 which engages the cam 46, and, to hold the bearing against the cam, there is a tension spring attached, at one end, to the link 48 and, at the other end, to the housing. The, construction of the cam is such that spring tension holds the heater elevated during most of the cycle of the apparatus. The heating platen is depressed briefly onto a package while the table is stationary.

The sprocket wheel 45 is connected via a chain 50 and a sprocket wheel 51 to the input shaft of a Geneva drive mechanism 52. The intermittent output of the Geneva drive is through a vertical shaft 53 on which the table is mounted.

The package ejector mechanism comprises a vertically reciprocating rod 54 pivotally connected at its bottom to one end of a cam actuated crank arm 55, the middle of which is pivotally mounted on the housing. There is a cam 56 on the input shaft of the Geneva drive which engages a bearing 57 on the crank arm 55. The cam raises and lowers the rod 54 which is normally held down by a spring 58, the bearing 57 consequently being urged upwardly against cam 56. During approximately 270 degrees of rotation of the input shaft of the Geneva drive and cam 56 while table 1 is stationary, cam 56 elevates rod 54 and theerfore piston 10. This construction causes the package to be elevated for removal by the arm 35.

The sweep arm 35 is secured at the top of a vertical shaft 60 mounted for rotation in a bearing in the housing. At the lower end of the shaft 60, there is attached one end of a connecting rod 61. The other end of the connecting rod carries a pin 62 and also is connected to a tension spring 63. The other end of the tension spring is attached to the housing and it pulls the connecting rod 61 to turn the shaft 60 and hence the sweep arm 35 to its retracted position.

There is a sprocket wheel 64, mounted to engage the chain 50, to which there is pivotally attached one end of a crank arm 65. At the other end of the crank arm 65, there is an elongated slot which receives the pin 62. As the sprocket wheel 64 turns, the crank arm 65 moves the connecting rod 61 against the tension of spring 63 and then provides lost motion as the sprocket wheel continues to turn. Consequently, the arm 35 sweeps a package from the table, retracts, and then remains stationary as the cycle of operation continues.

Electrical control of the moving parts of the apparatus is achieved by a microswitch actuated relay which operates the clutch-brake 38. The microswitch 66 is at the end of a conduit 67 pivotally mounted to the side of the package closing chamber 4. Normally, the switch is positioned adjacent to the package insertion station. The person who inserts packages closes the switch momentarily by pushing a long rod 68 to one side. This causes the clutch-brake 38 to operate and initiates a packaging cycle. In this cycle, a lid 'is placed on a package, gas is flushed through another package in chamber 2, a lid is heat sealed to a third package in chamber 4 and a fourth package is ejected. When all of the operations in a cycle are completed, the clutch-brake is reversed electrically by a mechanically-operated microswitch (not shown).

An important feature of the present invention is the opening into the mandrel 13, which is only slightly wider than the cup to assure proper alignment with the lid dispenser and heating platen. It may also help in keeping the lid bowed if the lid is a little wider than the cup and the opening into the mandrel so that the lid must be bowed in order to fit within the mandrel. However, a lid of aluminum foil or aluminum foil laminated to paper, which is preferred for its high efiiciency as a gas barrier, will remain bowed witout this construction. It also is possible to use a cardboard lid which is scored to fold into a bowed shape. These provide a further advantage in that, when the package is closed, the lid remains slightly elevated at its center for an attractive appearance.

The ledge 15 is recessed below the top of the table to provide space above the cup into which the lid is bowed. As a result, a tunnel is formed over the cup by the lid, but the bowed lid can still pass under the gasket which seals the chamber 2 to the rotating table 1. Gas flows through this tunnel and around the contents of the package, sweeping air before it to a vacuum at the other end.

A strong vacuum is not required, because removal of air is accomplished principally by a sweeping action. In practice, air is exhausted from chamber 2 through hose 21 by a positive displacement vacuum pump (not shown) at a rate of 80 cubic feet per hour. Another gas such as an inert gas from an external source is inserted into chamber 2 by hose 20' and fitting 18 at a rate of 100 cubic feet per hour. During a one-second dwell time, a typical package will be flushed approximately three times removing 85% of the original air and replacing it 'with another gas. The excess gas inserted into chamber is used to maintain a positive pressure in the flush chamber 2 and in heat seal chamber 4 thereby keeping air from leaking in under gasket 28. It is possible to omit the vacuum entirely, by using higher pressure of the other gas, but this is less desirable since there are greater gas losses and consequently higher costs.

Flushing efiiciency is increased and gas losses are minimized by the small size of the gas flushing chamber 2. The top of the chamber may be flush against the table so that the chamber is in efiect only within the recess in the mandrel 13.

The gas inlet and vacuum outlets are provided by holes in the top of the chamber 2 which open downwardly near the ends of the package. In the preferred embodiment, these holes are beyond the path in which the package moves, although they may overlap the ends of the package slightly. Since the top of the chamber is close to the lid, it is not necessary to continue the inlet and the outlet into the chamber, i.e. to extend the

elbow tubing connectors

18 and 19 below the top 17 of the chamber. However, if the top of the chamber is relatively high above the package, it may be desirable for them to extend into the chamber or to have the tubes open laterally toward the ends of the package.

In the preferred embodiment shown in the drawings, gas flow is facilitated by

extensions

66 and 67 of the ledge under the openings in the top of chamber 2. That is, the ledge 15 is only slightly larger than the package, at the sides, for package alignment, but is enlarged to form semicircular pockets, directly under the gas and vacuum inlets, having, for example, the same depth as the ledge 15. Gas flowing into one of these pockets is directed toward the package by the sides of the pocket, and similarly air flowing into one of the pockets from the package is urged upwardly to the vacuum tube.

The apparatus and method are useful for replacing air with any other gas. Ordinarily, the other gas will be an inert gas, since spoilage of products such as sliced luncheon meat is accelerated by oxygen in air. Carbon dioxide is a very suitable inert gas. However, it has been proposed that oxygen is desirable for preserving the freshness of certain products such as fresh meats and vegetables. It will be appreciated that the apparatus and method described above are just as useful for replacing air with oxygen-containing gases or any other gases as they are for flushing with inert gases.

Various modification of the structure of the apparatus and mode of operation are possible, without departing from the scope of the invention. For example, a package conveyor may be used which carries the packages in a straight path. Closing means other than heat sealing means may be substituted. Automatic package inserting equipment may be added; in that case the microswitch actuated relay control and clutch-brake might be omitted or the microswitch replaced with a device which detects the insertion of a package. The package may be made of other materials than plastic, for example, metal foil. Therefore, while preferred embodiments have been described and illustrated in the drawings, no limitation thereto is intended, the scope of the invention being defined by the appended claims.

We claim:

1. Apparatus for replacing air with another gas in a package which comprises a cup and a bowed lid over said cup forming a tunnel through which inert gas flows,

said apparatus comprising a conveyor for said package, means connected to a source of said other gas under pressure for discharging said other gas adjacent one side of said package, means for withdrawing air adjacent another side of said package, and means for moving said conveyor with said package along a path substantially perpendicular to the line connecting said gas discharging and air withdrawing means while said gas discharging and air withdrawing means are substantially stationary along said path, thereby providing relative movement between said package and said line so that said sides of said package move past the gas discharging and air withdrawing means at substantially the same time and gas flows through said package.

2. Apparatus as set forth in claim 1 in which said conveyor comprises a table having an opening to receive said cup and a recessed ledge at the edge of the opening in said table, whereby said cup may rest on said ledge and space is provided for said bowed lid above said cup but within said table, said gas discharge means and said air withdrawing means comprising conduits opening toward said ledge and said ledge being enlarged adjacent said conduits to form pockets, the sides of which deflect said other gas toward said package and air toward said air withdrawing means.

3. Apparatus as set forth in claim 1 including a gas flushing chamber having a side opening against said table and forming a relatively gas-tight seal therewith, said bowed lid passing under a wall of said flas flushing chamber as said table moves, and said gas discharge means and air withdrawing means opening into said chamber.

4. Apparatus as set forth in claim 1 in which said means for moving said conveyor includes means for stopping the conveyor when a package is adjacent said gas discharge means and air Withdrawing means.

5. Apparatus as set forth in claim 1 including means for hermetically sealing said lid to said cup.

6. Apparatus as set forth in claim 5 including means for removing a sealed package from said conveyor.

7. Apparatus as set forth in claim 2 in which said conveyor is a rotating table and said means for moving said conveyor comprises means for rotating said table.

8. Apparatus as set forth in claim 3 in which said ledge is enlarged adjacent said gas discharge means to form pockets, the sides of which deflect said other gas towards said package and air toward said air withdrawing means.

9. In an apparatus for flushing an at least partially open container with gas comprising:

a plurality of wall members defining a partially enclosed gas flushing chamber,

a conveyor in sliding engagement with at least some of said walls to substantially close said chamber and for moving said container into communication with the interior of said chamber to be flushed with gas, said conveyor comprising a moving wall of said chamber,

said conveyor having an opening receiving said container and an elevated lid on said package, and means for supporting said container and lid within said opening and below the surface of said conveyor,

means connected to a source of said gas for discharging said other gas adjacent one side of said container, means for withdrawing air adjacent another side of said package,

and means for moving said conveyor slidably past said plurality of wall members,

whereby said container may be placed in said conveyor 7 v 8 outside said chamber with a lid resting on it and gas discharging and air withdrawing means permitpartially elevated to permit access of gas into said ting increased gas flow time. container and whereby sa'id container with said elevated lid may be moved into said chamber past References Cited the wall members which slidably engage said conveyor without substantial gas leakage from said UNITED STATES PATENTS chamber to the atmosphere; 3,189,505 6/1965 Sloan et a]. 53-22 X the improvement in which said means for moving said 3,196,590 7/ 1965 Ollier et a1. 53112 conveyor moves the packages along a path substantially perpendicular to the line connecting said 10 TRAVIS S. MCGEHEE, Primary Examiner.