Patent ID: 6142463
Filing Date: 2000-11-07
Classification: B65H

Abstract:
A lifting system for an automatic pile changing device of a sheet-processing machine, the system comprising: a main pile-carrying assembly for moving a pile of sheets; an auxiliary pile-carrying assembly for moving either synchronously or asynchronously with respect to the main pile-carrying device; first and second drive units for driving the main and auxiliary pile-carrying assemblies, respectively; a control unit for providing a common control signal to the first and second drive units for synchronously driving the main and auxiliary pile-carrying assemblies; at least one of the drive units including a conversion means for converting the common control signal into a switch-on signal having frequency and duration attributes derived from differences between speed and acceleration characteristics of the main pile carrying assembly and the auxiliary pile carrying assembly, the switch-on signal causing the at least one drive unit to move its respective pile carrying assembly the same distance and speed as the other pile carrying assembly in response to the common control signal, thereby allowing for the synchronous driving of the main and auxiliary pile-carrying assemblies.