Patent ID: 6460991
Filing Date: 2002-10-08
Classification: B41J,B65H

Abstract:
A vacuum drum assembly for a printing machine, comprising:a drum having a length and a periphery with an array of passageways distributed along its length and around its periphery to permit air to flow from outside the drum to inside the drum in response to reduced air pressure inside the drum, and an array of valve members, each valve member being opened by mechanical actuation and movable between a closed position in which that valve member restricts at least one of the passageways and an open position in which the restriction of the at least one passageway is reduced; the arrangement being such that, when a partial area of the drum is wrapped with a material to be printed, at least some of the valves for the passageways adjacent an edge of that area are open, and valves for the passageways which are not covered by the material to be printed and which are not adjacent an edge of that area are closed.