SHEET HANDLING APPARATUS WITH ROTARY DRUM

摘要

A sheet handling apparatus comprising a rotary drum (10) having an outer peripheral wall (12) with perforations (14), and a number of separate chambers (20), a suction system for controlling a flow of air through the perforations, thereby to attract sheets to the peripheral wall of the drum, and a stationary shutter member (38; 38') for blocking the flow of air through the perforations when they pass through a predetermined angular range. The number of separate chambers extend in an axial direction and are distributed over the periphery of the drum. A disk-shaped manifold (24;24') at the first axial end of the drum is co-rotatably with the drum. The manifold forms a number of radial channels (26) each connected to one of said chambers and having an opening (50; 50') at a radially inward end of each channel. The stationary shutter member is arranged for blocking an opening of a channel to block air flow from a radially inward end of a channel.