Patent ID: 6021629
Filing Date: 2000-02-08
Classification: B29C,B65B

Abstract:
A sealed tray packaging machine with a registration system, comprising:a plate conveyor having a plurality of plate segments each for carrying a tray to be sealed;a rotary heat sealing drum positioned over the discharge end of the conveyor, said drum coming in contact with the top edges of every tray passing thereunder on said plate conveyor, for sealing any film laying on top of each tray to the top edges thereof;a film ribbon delivery structure for holding a roll of sealing film and delivering it in parallel above the tray carrying plate conveyor onto and parallel to the top edge of trays carried by said plate conveyor, and thereby under said rotary heat sealing drum;a cutter to cut the film ribbon between successive trays, said cutter being positioned at the discharge side of said rotary heat seal drum;an electrical control circuit and timing cam for generating timing signals to said electrical control circuit,a sensor for sensing registration marks on the film delivered by said film delivery structure and sending registration mark sensed signals to said control circuit;wherein said control circuit initiates an indexing signal when said registration mark sensed signal is not synchronized with said cam generated timing signal;an indexing blade and heat film tacker structure above said conveyor connected to said control circuit to receive an indexing signal and to operate to intercept the film ribbon and move the intercepted point down thereby pulling the film ribbon forward with respect to a tray position and to tack seal said forwardly pulled film against the leading edge of an adjacent tray;a drive motor and drive chain connected to move said conveyor, said film feed structure, said heat seal drum, said cutter and said indexing blade and heat film tacker; andsaid structure comprising an indexing blade mounted on a rotating heat tacking bar and a vertical positioning structure connected to said control to reciprocate said tacking bar to intercept said film ribbon.