Device and method for separating and aligning sheets in a sheet feeder of a printing machine

摘要

A sheet feeder for a sheet-fed printing machine having a cylinder with a gripper system, movable suction conveyors for separating individual sheets from a sheet pile, the suction conveyors being disposed adjacent one another in a sheet-conveying direction, and groups of revolving adjustable conveying elements for aligning the sheets on a drive side and on an operating side of the printing machine in association with the suction conveyors and cooperating therewith for feeding the sheets to the gripper system of the cylinder of the printing machine, includes a drive system for driving the groups of conveying elements independently of one another and with varied speed so as to align the sheets on both of the sides of the printing machine, and a device disposed at locations of the revolving conveying elements for querying the sheet edges and for generating, in accordance with a response to a respective query, an electric pulse for controlling the drive system; and a method of separating and aligning the sheets in the sheet feeder.