Method for automatically feeding a printing plate to a plate cylinder in a printing machine

A method for automatically feeding a printing plate in proper registry to a plate cylinder in a printing machine, the printing machine having a clamping rail associated with the plate cylinder for clamping the leading edge of the printing plate, the method comprising the steps of:

• (a) securing the printing plate on a plate conveyor;
• (b) actuating the plate conveyor to advance the printing plate toward the clamping rail;
• (c) sensing the in-register condition of the leading edge of the printing plate at two independent sensing sites in the clamping rail;
• (d) releasing the printing plate from the plate conveyor for a predefined period of time if the leading edge of the printing plate is sensed to be in registry at only one of the two sensing sites to permit the printing plate to change its orientation under its own weight;
• (e) securing the printing plate on the plate conveyor after the predefined period has passed to resume the advancement of the printing plate;
• (f) repeating steps (c) through (e) until the in-register condition of the leading edge of the printing plate is sensed at both sensing sites;
• and,
• (g) clamping the leading edge of the printing plate in the clamping rail after the in-register condition is sensed.