Packaging machine

Claim 2

A machine for packaging products in packages formed by heat sealing a flexible cover onto a tray, the tray including a product-receiving pocket surrounded by a peripheral flange and containing slit means therein defining a deflectable strip, comprising a tray carrier on which the tray is supported, an upward slit-lifting protuberation fixedly mounted on said tray carrier for engaging and lifting the deflectable strip to define a flow passage through the slit means into the product-receiving portion of the tray, preliminary heat sealing means for forming a peripheral seal between the flexible cover film and the flange of the tray partway around the outer periphery of the tray, leaving said flow passage unsealed, means establishing a fluid passage through the protuberance, and final heat seal means for completing the peripheral seal around the tray.

Claim 3

A machine for packaging products in packages which includes a tray having product-receiving pockets and a pair of spaced-apart slits which define a deflectable strip, comprising a plurality of tray carriers, each having a passage therethrough, means for transporting the carriers along a predetermined path with a product-containing tray in each of the carriers, means for depositing a cover in overlying relation on each of the trays in succession, a vacuum source, a member mounted fixedly on each of the carriers for engaging the deflectable strip and holding it and the overlying cover away from the body of the tray to communicate the tray pockets with the carrier passage, conduit means coupled to the vacuum source engageable with the passage of each tray carrier in succession for evacuating the package units, and means for sealing the cover to the tray to close the evacuated package units.

Claim 4

A machine for packaging products in packages which includes a tray having product-receiving pockets and a pair of spaced-apart slits which define a deflectable strip, comprising a plurality of tray carriers, each having a passage therethrough, means for transporting the carriers along a predetermined path with a product-containing tray in each of the carriers, means for depositing a cover in overlying relation on each of the trays in succession, a vacuum source, a member mounted fixedly on each of the carriers for engaging the deflectable strip and holding it and the overlying cover away from the body of the tray to communicate the tray pockets with the carrier passage, conduit means coupled to the vacuum source engageable with the passage of each tray carrier in succession for evacuating the package units, and means for sealing the cover to the tray to close the evacuated package units.

Claim 5

A machine according to claim 2 wherein the sealing means includes an initial seal forming mechanism movable into engagement with the package covers before evacuation of the package units and having heat sealing bars for forming initial seal portions between the covers and base members about the perimeters of the pockets except in the portions of the perimeters between the pockets and the deflectable strip, and a final seal mechanism movable into engagement with the cover after evacuation of the package units and having spaced-apart sealing bars thereon for forming final seal portions between the slits and the pockets of the trays and overlapping the ends of the initial seals.

Claim 6

A machine for packaging products in a package which includes a tray having product-receiving pockets and spaced-apart slits defining a deflectable strip in the tray, comprising tray carriers, each having a passage therethrough, means for transporting the carriers in succession along a predetermined path at a substantially constant rate of speed with a product-containing tray in each carrier, means for delivering covers in overlying relation onto the moving trays to form package units, a member movable back and forth in a direction parallel to the path of movement of the package units in timed relation to the movement thereof, a vacuum source, a vacuum head coupled to the source and mounted on and movable with the member and engageable in succession with each carrier passage to evacuate the package units, and a member fixedly mounted on each of the carriers for holding the deflectable strip of each tray and the cover thereover away from the body of the tray to form openings communicating the tray pockets with the carrier passages.

Claim 7

A machine for packaging products in a package which includes a tray having product-receiving pockets and spaced-apart slits defining a deflectable strip in the tray, comprising tray carriers, each having a passage therethrough, means for transporting the carriers in succession along a predetermined path at a substantially constant rate of speed with a product-containing tray in each carrier, means for delivering covers in overlying relation onto the moving trays to form package units, a member movable back and forth in a direction parallel to the path of movement of the package units in timed relation to the movement thereof, a vacuum source, a vacuum head coupled to the source and mounted on and movable with the member and engageable in succession with each carrier passage to evacuate the package units, and a member fixedly mounted on each of the carriers for holding the deflectable strip of each tray and the cover thereover away from the body of the tray to form openings communicating the tray pockets with the carrier passages.

Claim 8

A machine according to claim 4 wherein the strip holding member includes passage means and a tubing in communication with the package unit openings, and the vacuum head includes a conduit engageable with the tubing for communicAting a source of an inert gas to the package unit.

Claim 9

A packaging machine comprising means including tray carriers for transporting product-containing trays in succession along a predetermined path, said tray carriers each having a passage therethrough and a member mounted within said passage for engaging said trays, means for pressing and compacting the product in the trays at a first station along the path, means at a second station for delivering covers in overlying relation onto the moving trays to form package units, and means for evacuating the interiors of the package units and sealing the covers to the trays.

Claim 10

A packaging machine comprising means including tray carriers for transporting product-containing trays in succession along a predetermined path, said tray carriers each having a passage therethrough and a member mounted within said passage for engaging said trays, means for pressing and compacting the product in the trays at a first station along the path, means at a second station for delivering covers in overlying relation onto the moving trays to form package units, and means for evacuating the interiors of the package units and sealing the covers to the trays.

Claim 11

A machine according to claim 6 wherein the compressing and compacting means comprises a carriage spaced from the path of movement of the trays, means for reciprocating the carriage back and forth along a path substantially parallel to the path of movement of the trays, a pressing member carried by the carriage and engageable with the product to compact it in the trays, and means for selectively moving the pressing member into engagement with the product upon movement of the carriage in the direction of the trays and for withdrawing the pressing member out of engagement with the product before the carriage returns in an upstream direction.

Claim 12

A machine according to claim 7 wherein the moving means includes an elongated member disposed substantially parallel to the path of movement of the carriage and having a cam surface thereon, a cam follower coupled to the pressing member and engaging the cam surface, releasable means for holding the cam member in a predetermined position as the carriage moves forward in the direction of movement of the trays and for releasing the cam member to enable it to be moved out of operable relation before the carriage moves back, whereby the pressing member is disengaged from the product before it is moved back, and resetting means for moving the cam member back into operable position for engagement by the releasable holding means before the carriage moves forward.

Claim 13

Apparatus according to claim 8 wherein the tray carriers have passages therein communicating the space between the trays to the exterior thereof and comprising means carried by the carriage and engageable with the carrier passages for creating a differential pressure across the tray effective to retain the tray in the carrier throughout the pressing operation.

Claim 14

In a packaging machine, apparatus for attaching cover films to product-containing trays to form packages and for evacuating and closing the packages, the trays having product-receiving pockets and spaced-apart slits defining a deflectable strip and continuously moving in succession along a predetermined path on tray carriers, each of which has an evacuating passage formed therein and a fixed element holding the deflectable strip and cover film away from the body of the tray to communicate the carrier passage with the package interior, comprising a first member having heated sealing bars for heat sealing the cover film to the tray about portions of the perimeters of the tray pockets except in the regions of the perimeters between the pockets and the slits, a second member having seals engageable with the tray carriers for forming, with each carrier in succession, a chamber containing the package, a vacuum source, an evacuating head movable into engagement with the evacuating passages of the successive carriers to communicate the vacuum source with the package interiors, means for reciprocating the first and second members and the vacuum head back and forth in timed relation to and conjointly with the movement of each tray through a predetermined distance, and means for moving the first and second members and the vacuum head, respectively, into and out of operative engagement with the tray and carrier.

Claim 15

In a packaging machine, apparatus for attaching cover films to product-containing trays to form packages and for evacuating and closing the packages, the trays having product-receiving pockets and spaced-apart slits defining a deflectable strip and continuously moving in succession along a predetermined path on tray carriers, each of which has an evacuating passage formed therein and a fixed element holding the deflectable strip and cover film away from the body of the tray to communicate the carrier passage with the package interior, comprising a first member having heated sealing bars for heat sealing the cover film to the tray about portions of the perimeters of the tray pockets except in the regions of the perimeters between the pockets and the slits, a second member having seals engageable with the tray carriers for forming, with each carrier in succession, a chamber containing the package, a vacuum source, an evacuating head movable into engagement with the evacuating passages of the successive carriers to communicate the vacuum source with the package interiors, means for reciprocating the first and second members and the vacuum head back and forth in timed relation to and conjointly with the movement of each tray through a predetermined distance, and means for moving the first and second members and the vacuum head, respectively, into and out of operative engagement with the tray and carrier.