Apparatus for gumming and folding open end envelopes

Abstract

A transfer cylinder is rotatably mounted in a machine frame and is positioned in spaced parallel relation with a rotatable delivery cylinder. A side fold cylinder is positioned intermediate the transfer and delivery cylinders. The transfer cylinder conveys the envelope blank onto the periphery of the side fold cylinder. Rotation of the side fold cylinder with the envelope blank retained thereon folds the side flap and advances the folded envelope into engagement with the delivery cylinder. A gumming cylinder having an adhesive applicator portion is positioned adjacent the delivery cylinder and is operable to apply a strip of adhesive to the exposed bottom flap of the envelope blank as the blank is transferred from the delivery cylinder to the gumming cylinder. A selected amount of the adhesive is transferred from a reservoir by a roller to the surface of the adhesive applicator. The gumming cylinder rotates in timed relation to the delivery cylinder and in an opposite direction. The gummed envelope blank passes from the delivery cylinder and is engaged by a backup roller to transfer the envelope blank onto the upper surface of the gumming cylinder. The gumming cylinder feeds the envelope blank to a folding device that includes a plowshare and a formerblade. The bottom flap is folded and adhesively secured to the side flap while the top flap is folded in overlying relation with the side flap to close the open end of the envelope.

Dependencies are inferred from the claim text.