Magnetic drum duplicating machine - has excess powder collector with helical screw and scraper across drum discharging into groove for collection below

摘要

The magnetic drum duplicating machine which attracts a powdered pigment to areas of its surface corresp. to the printed areas of the original, for transfer to a copy sheet, includes a cleaning system for the drum. Any remaining particles which pass the demagnetising head, travel under a helical screw (24) across the top. This is driven by a motor at one end. A scraper (22) behind the screw discharges the excess powder into a groove around the other end of the drum and this powder falls onto a magnetic elastic band (29) in the groove and carried downwards. This is then removed by a scraper (31) at the bottom to fall into a collector tray (16) below.