US3444665A

US3444665A - Vacuum packaging apparatus

Info

Publication number: US3444665A
Application number: US588423A
Authority: US
Inventors: William F Prena
Original assignee: John Morrell and Co
Current assignee: Smithfield Packaged Meats Corp
Priority date: 1966-10-21
Filing date: 1966-10-21
Publication date: 1969-05-20
Anticipated expiration: 1986-05-20

Description

y 0, 969 w. F. PRENA 3,444,665

VACUUM PACKAGING APPARATUS Filed Oct. 21, 1966 Sheet I of 2 INVENTOR. WILLIAM F. PRENA ATTORNEYS.

United States Patent 3,444,665 VACUUM PACKAGING APPARATUS William F. Prena, Norridge, 111., assignor, by mesne assignrnents, to John Morrell 8: Co., Chicago, 111., a corporation of Delaware Filed Oct. 21, 1966, Ser. No. 588,423 Int. Cl. B65b 31/02, 63/00 US. Cl. 53112 6 Claims ABSTRACT OF THE DISCLOSURE This invention relates in general to packaging apparatus, and more particularly to apparatus for packaging articles in a substantially evacuated receptacle.

In the past, it has been known to provide vacuum packaging apparatus with an intermittently driven endless conveyor having a plurality of compartment defining members thereon movable from a film drawing station where in a first layer of film is clamped, heated and drawn into one of the compartment forming members to form a receptacle, to a loading station where the articles to be packaged are placed in the receptacle, to a sealing station where a second layer of film is sealed to the receptacle as the air therewithin is withdrawn, and to a package removal station where the packages are removed from the conveyor.

In the past it has been conventional to provide mechanical structure for moving the film drawing means into and out of suction applying relationship with the compartment defining members at the film drawing station. This structure has proven to be relatively expensive to manufacture and assemble, and somewhat troublesome in use. Accordingly, one of the objects of the present invention is to provide an improved film drawing suction means which does not require mechanical means for moving the same, and which is yieldably mounted at a substantially fixed position on a vacuum packaging machine to enable the compartment defining members to move into engagement therewith.

Another object of the invention is to provide a vacuum packaging machine with a plurality of suction applying means for drawing film into compartments, and for retaining the film in the compartments after it has been drawn; said suction applying means each being yieldably mounted on the machine so as to align themselves properly against the bottom of the compartment forming members.

A further object of the invention is to provide suction drawing means as described above with cam surfaces facilitating the movement of the compartment defining members therepast.

Still another object of the invention is to provide suction drawing means as described above with means for adjusting the elevation of the same relative to the compartment defining members, so that the suction drawing members can be adjusted to yieldably engage the compartment defining members with a predetermined force.

In prior art vacuum packaging machines, it has been conventional to provide spindle assemblies upon which a supply roll of film is mounted. Heretofore, the core of the film supply roll rotated on the spindle as the film was fed to the machine. With such spindle assemblies, brake means were usually provided for the film supply spindle to maintain proper tension in the film during the feeding thereof. Since film supply roll cores are not usually formed with any degree of accuracy, the frictional resistance between the spindle and the core varied widely, and the eifect of the brake means has not been consistent. Accordingly, it is still another object of the invention to provide an improved film supply spindle assembly for a vacuum "ice packaging machine. A related object of the invention is to provide a spindle assembly for a vacuum packaging machine wherein the film supply reel core is positively fixed on a hub that is rotatably mounted on accurately aligned bearings.

These and other objects of the invention will hereinafter become more fully apparent from the following description, taken in connection with the annexed drawings, wherein:

FIG. 1 is a side elevational view of a vacuum packaging machine, with certain parts broken away for clarity of illustration;

FIG. 2 is an enlarged, fragmentary side elevational view of one of the improved film drawing suction means of the present invention;

FIG. 3 is an enlarged section taken generally along line 33 of FIG. 1;

FIG. 4 is an enlarged side elevational view of the improved spindle assembly of the present invention, taken from the side of the machine opposite of that shown in FIG. 1; and

FIG. 5 is a section view taken generally along line 5-5 of FIG. 4.

While this invention is susceptible of embodiment in many different forms, there is shown in the drawings and will herein be described in detail a preferred embodiment of the invention with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the embodiment illustrated. The scope of the invention will be pointed out in the appended claims.

The vacuum packaging machine of the present invention is similar in many respects to that disclosed in Myers application Ser. No. 516,559, filed Dec. 27, 1965, now Patent No. 3,397,507, issued Aug. 20, 1968, and assigned to the assignee of the present application. The vacuum packaging apparatus illustrated in the present application differs from that disclosed in the Myers application in that the present application discloses a single line vacuum packaging machine, that is, a machine wherein'each tray or receptacle includes a single compartment; whereas the Myer-s application discloses a packaging machine wherein each tray or receptacle includes a pair of side by side compartments. It should be understood that the improvements of the present invention have generally utility, and can be used in a double line packaging machine, as well as a single line packaging machine.

Referring now to the drawings, a vacuum packaging machine 10 is shown to include a frame having spaced uprights 11 and supporting an elongate beam 12 with brace members 13 extending between uprights 11 at the lower ends thereof. A plurality of compartment defining trays or receptacles 14 are mounted on an endless conveyor defined by a plurality of pivotally interconnected links 15'. The conveyor links 15 are trained over sprockets, such as shown at 16 at the rearward end of the machine, and the conveyor is driven from motor M by suitable drive means within housing H. The drive means may take the form of that disclosed in the above mentioned Myers application, and such drive means is arranged to intermittently move the conveyor in a clockwise direction as viewed in FIG. 1.

Spindle assemblies 17 and 18 are provided at the rearward and forward ends of the machine, respectively, and spindle assembly -17 is adapted to rotatably support and guide a first roll of film toward a film drawing station 19', while spindle assembly 18 is adapted to rotatably support and guide a second roll of film toward a sealing station 20. Film clamping members, not shown, are preferably provided at opposite sides of each tray 14 for clamping opposite edges of the film being fed from spindle assembly 17. Tuckers, either fixed or movable, are also preferably provided for tucking the edges of the film from spindle assembly 17 under the film clamping members. A heater 21 is provided at the film drawing station 19, and heater 21 heats the clamped film so that it is readily stretchable and can be drawn downwardly into the compartment within the tray 14 at the film drawing station 19, as will hereinafter appear. The film from spindle assembly 18 is sealed around the periphery of the film in tray 14 at the sealing station 20 as the interior of the thus formed package is evacuated by a sealing and evacuating head 22, which may take the form of the sealing and evacuating head disclosed in the above mentioned Myers application.

The means for initially drawing the film from spindle assembly 17 into the compartment within tray 14 at the film drawing station '19, and for then positively retaining the film within the compartments, will be best understood from a consideration of FIGS. l-3. As is shown in FIG. 1, a first length of pipe is secured to beam 12 at the film drawing station 19, and a second substantially longer length of pipe 26 is secured to beam 12 forwardly of pipe 25. Pipe 25 is closed at both ends, and the mid-portion thereof is connected to a first suitable vacuum drawing source, such as pump 27. The rearward end of pipe 26 is closed, and the forward end of pipe 26 is connected by a line 28 to a second suitable vacuum drawing source, such as pump 29. A plurality of bored fittings 29 are fixed to beam 12 at longitudinally spaced positions therealong, and pipe clamping means 30 are secured to

pipes

25 and 26 in vertical alignment with fittings 29. A threaded shank 31 extends downwardly from clamping means 30 (FIG. 3) into fitting 29, and a nut 32 threadably engages shank 31 and bears against the upper surface of fitting 29, so that the

pipes

25 and 26 can be adjusted vertically relative to the beam 12. Internally threaded openings 33 are provided in

pipes

25 and 26 at longitudinally spaced positions therealong, and tubular stems 34 are mounted in openings 33 to establish communication between the

pipes

25 and 26 and vacuum applying means 35 to be hereafter described.

Pipes

25 and 26 cooperate to define manifold means for connecting the sources of vacuum with the vacuum applying means.

As is clear from FIG. 2, the trays'14 each include a boss 14a at the lower end thereof, and a vertical bore 36 extends through each boss 144: into the compartment defined within member 14. Each vacuum applying means 35 is defined by an elongate, flat strip of suitable material, such as a rigid plastic, and strips 37 include a pair of openings 38 that are spaced an amount corresponding to the distance between bores 36 in adjacent trays 14. Vacuum drawing assemblies 35 further include a pair of suction cups 39 cemented, or otherwise suitably secured, to the lower surface of strips 37 beneath openings 38. Suction cups 39 include a hollow, generally frusto-conically shaped portion 40 immediately beneath strip 37, and a further generally cylindrically shaped lower portion 41. A vertical bore 42 is provided in each suction cup portion 41 in vertical alignment with the opening 38 in strip 37, and stems 34 from the manifold means are each positioned within a bore 42 to establish communication between the vacuum applying source and the compartment within member -14.

The suction applied by the means 35 at the film drawing station 19 is sufiiciently strong to draw the heated film from spindle assembly 17 downwardly into the compartment within the tray 14 at the film drawing station, to form the lower half of a package. The vacuum source communicating with the vacuum applying means 35 connected to the pipe 26 is sufiiciently strong to insure that the partially formed packages will be retained within the compartments in the trays 14. After the trays 14 move out of the initial film drawing station above pipe 25, the articles to be packaged can be placed within the partially formed packages that are positively held within the compartments in trays 14 by the suction applying means 35 communicating with pipe 26.

Suction cups 39 are formed of a resilient rubber-like material, so that the strips 37 are yieldably mounted with respect to the

pipes

25 and 26. Inclined or rounded camming surfaces 43 are provided at opposite ends of each strip 37 to facilitate movement of the members 14 onto and off of the strips 37. The suction cups 39 on each strip 37 are spaced a distance equal to the spacing between the forwardmost suction cup and the rearwardmost suction cup on adjacent strips 37, so that the trays 14 can be indexed in equal increments along the machine.

In use, the nuts 32 are adjusted to position the pipes 25 and 26 (and thereby the suction applying means 35), so that the upper surface of strips 37 will engage the undersurface of bosses 14a with a predetermined amount of force thereby preventing leakage between

openings

36 and 38. Strips 37 are yieldably urged against the bottom of bosses 14a by the resilient suction cups 39 to maintain the proper seal between the strips 37 and bosses 14a. Suitable control means, not shown, are provided for sequencing the application of suction to the suction applying means 35, so that the suction is applied through

manifold pipes

25 and 26 only when the trays 14 are properly positioned with the bores 36 in alignment with openings 38. Since strips 37 are substantially longer than the distance between suction cups 39, a boss 14a on a tray 14 will always be in engagement with the upper surface of strip 37 to maintain the suction cups 39 in a slightly c0mpressed condition, thereby facilitating movement of the next boss 14a onto the strip 37. From the foregoing, it will be readily apparent that an extremely simple, yet effective, vacuum applying means has been provided, which completely eliminates the need for mechanical means to move suction applying members into and out of engagement with compartment forming trays.

Referring now to FIGS. 4 and 5, the spindle assembly 18 for supplying film to form the upper portion of the package at the final sealing station is illustrated in detail. Said assembly includes a manually operable handwheel 45 that is fixed to the end of an adjusting shaft 46. Shaft 46 is rotatably supported within a bearing housing 47 adjacent handle 45, and housing 47 is held against rotation relative to the machine frame by the sliding engagement of a bolt 49 through clearance openings in a frame portion 48 and the housing 47. The opposite end of bolt 49 is received within a threaded opening in an upright arm 50, and a nut 51 positively fixes bolt 49 to arm 50 for movement of the arm 50 relative to the machine frame.

The left-hand end of shaft 46, as viewed in FIG. 5, 1s externally threaded, and a traveller, in the form of an elongate, generally cylindrical nut 52, is threadably mounted thereon. The outer end portions 52a of nut 52 are of reduced diameter, and

bearings

53 and 54 are recelved thereover. A mounting plate 55 is fixedly secured to arm 50, as by screws 56; and plate 55 is also fixedly secured to nut 52, as by screws 57. Spindle assembly 18 further includes a generally cylindrical spool member 58 having a transverse web portion 59 at the outer end thereof rotatably supported upon bearing 53. The opposite end 60 of spool 58 is seated against a shoulder 61 on an end plate 62, and is positively held thereagainst by screws 63. End plate 62 includes an axially extending hub portion 64 that is rotatably mounted on bearing 54. End plate 62 further includes a portion that extends radially outwardly of spool 58, and a plurality of pin-like projections 65 extend axially outwardly therefrom. From the foregoing, it will be apparent that as shaft 46 is rotated by handwheel 45, the entire assembly consisting of nut 52, spool 58, and end plate 62 can be adjusted axially relative to the machine frame. Spool 58 is adapted to receive a roll of film thereover, and the axial adjustability thereof is extremely important in aligning indicia on the film with the lower package part. A split ring clamping member 67 is movable axially of the spool 58 to force the pin-like projections 65 into the core of the film reel to positively hold the reel on the spool 58, and clamping member 67 may be tightened upon the spool 58 by bolt 68. A hearing retainer plate 69 is preferably bolted to the spool web 59 to positively retain the bearing 53.

An arm 70 is pivotally mounted on arm 50 by pin 71, and arm 70 carries a transverse guide roller 72 at the upper end thereof; said guide roller 72 having the film from spool 58 trained thereover. Arm 70 is biased in a clockwise direction, as viewed in FIG. 4, by a spring 73 connected between arm 70 and the upper end of arm 50, thereby insuring that the film will be taut.

Brake means 75 is provided for preventing overrunning of the spool 58, and to insure a proper amount of tension in the film being fed from spool 58, so that the film will remain flat. Brake means 75 includes an arm 76 pivotally secured to arm 50 by pivot pin 78, and carrying a brake shoe 79 on the undersurface thereof that bears against the cylindrical surface 62a of end plate 62. A spring 80 is connected between the outer end of arm 76 and an extension 50a of arm 50 to bias the arm 76 in a clockwise direction, as viewed in FIG. 4. An adjustable brake controlling member 81 is threaded through a portion 70a of arm 70, and an abutment member 82 at the lower end of member 81 is urged into engagement with the upper surface of arm 76 by spring 73. In this manner, the braking force imparted to the spool 58 is responsive to the tension in the film passing over the guide roller 72, so that when the tension in the film increases to pivot arm 70 in a counterclockwise direction, as viewed in FIG. 4, the braking force is reduced so that the film will be fed from the spool more quickly.

From the foregoing, it is believed apparent that a novel spindle assembly has been provided which accurately rotatably supports the film roll, and which provides adjustment means so that the film roll can be accurately positioned.

I claim:

1. In a vacuum packaging machine having a conveyor with a plurality of trays thereon, each of said trays having a compartment therein with a passage opening outwardly thereof, said trays being movable by said conveyor to a series of vacuum applying stations, means for applying a vacuum in said compartments at said stations comprising: manifold means positioned adjacent said stations; means connecting said manifold means with a vacuum drawing source; a plurality of spaced outlet openings in said manifold means; a plurality of strips adjacent said manifold means, each strip being positioned to engage at least a pair of adjacent trays when they are in adjacent vacuum drawing stations, each strip having at least a pair of openings therein spaced an amount corresponding to the distance between the passages in adjacent trays, whereby the openings in each strip may be placed in communication with a passage of tray; and resilient means connecting said strips and said manifold means, said resilient means having openings therein each communicating with an outlet opening of said manifold means whereby a vacuum may be drawn in each of said compartments, said resilient means urging said strips against said trays in sealing engagement therewith.

2. A vacuum packaging machine as set forth in claim 1 wherein said trays have a boss on the bottom thereof, and at least one end of each strip has a cam surface positioned to engage the bosses on said trays as they pass thereby.

3. A vacuum packaging machine as defined in claim 1 wherein means is provided for adjusting said manifold means relative to said conveyor.

4. A vacuum packaging machine as defined in claim 1 wherein said resilient means is defined by a pair of spaced cup members secured to each strip, each of said cups having an opening therethrough.

5. A vacuum packaging machine as defined in claim 4 wherein a tubular stem is mounted in each opening of said manifold means, each stern being received in one of said cup openings.

6. A vacuum packaging machine as defined in claim 2 wherein the distance between adjacent strips is less than the distance between the bosses on adjacent trays.

References Cited UNITED STATES PATENTS MORSE, JR., Primary Examiner.

US. Cl. X.R.

WAYNE A.