Abstract: Apparatus and method for assembling and attaching zipper closure means in strip form to open ends of flat sacks fed serratim into an attachment station. Consecutive sections of the closure means must be in proper registration with the sacks in such station. Assembly of the sections with the sack ends is coordinated by monitoring relative orientation of the sections and the sacks and automatically correcting for deviations from the registration.

Abstract: A bag tube feeder has an intermittently operated conveyor supporting a row of aligned stacks of bag tubes with a plurality of movable suction cups positioned over an outfeed station in which a stack of bag tubes is positioned. A pair of pneumatic cylinders lowers the suction cups to engage the uppermost bag tube, then lift the bag tube and a pneumatic cylinder swings the bag tube into the nip of a roller and an outfeed conveyor belt which takes the bag tube to a discharge location. A photo-electric sensor senses lowering of the stack of bag tubes in the outfeed station to automatically actuate a pneumatic cylinder arrangement for lifting the discharge end of the conveyor to maintain the top of the stack in a desired position. A mechanical sensor senses the depletion of the stack in the outfeed station to initiate actuation of the stack infeed conveyor to move the next adjacent stack into the outfeed station automatically.