Apparatus for closing plastic bags

Claim 1

Apparatus for closing open-mouth heat-sealable plastic bags after they have been packed and filled out by their contents comprising a receiver for a packed bag movable after receiving the bag to position it at a first station with the bag standing upright with its open mouth at the top, a carriage movable between a retracted position with respect to the first station to an operative position above the first station over the top of a bag in the receiver at the first station, means carried by the carriage operable when in its operative position for bringing marginal portions of the opposed walls of the bag at the first station above the bag contents at the mouth end of the bag into face-to-face relation generally throughout the width of the walls with these face-to-face marginal portions extending generally centrally across the top of the contents and extending upwardly from adjacent portions of the walls folded over on top of the contents and extending beyond the ends of the top of the contents with portions of the walls of the bag forming ears projecting outwardly at the ends of the top of the contents, said means comprising a pair of spreading fingers and means mounting them on the carriage for movement down into the open mouth of the bag and laterally outwardly relative to the bag in the mouth of the bag to spread it flat, means carried by the carriage for heat-sealing said face-to-face marginal portions together on a first line of seal extending transversely of the bag and reaching into the ears, said marginal portions constituting a flap, means for moving the bag out of the receiver from the first station to a second station, and means at the second station for heat-sealing the ears on second and third lines of seal at the ends of the top of the contents, each of said second and third lines of seal extending across the base of the respective ear at the respective end of the top of the contents and each intersecting the said first line of seal.