Process and apparatus for automatic stack changing

US5769413A · kind A · utility

Assignee

• MAN Roland Druckmaschinen AG · DE

Inventors

• Peter Hummel · Offenbach, DE
• Robert Ortner · Alzenau, DE

Key dates

• Filing date: Feb 14, 1997
• Grant date: Jun 23, 1998
• Expiry date: Feb 14, 2017

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B65H2801/21
• WIPO field: Handling
• WIPO sector: Mechanical engineering

Abstract

A process and apparatus for automatically changing the stack of sheets in a sheet-fed printing machine is disclosed comprising sheet-carrying surfaces, sheet-separating devices, a pallet, sensors and a control system. The sheet-carrying surfaces act in concert with the sheet-separating devices to create an auxiliary stack separate from the existing stack of printed sheets. In this manner, the existing stack of sheets are removed and the auxiliary stack is deposited on a new stack base as brief and as closely coordinated as possible. The timing of the transition from the sheet-separating devices to the sheet-carrying surfaces is coordinated such that, even in the case of thin printing materials, the stack changing apparatus functions properly during the stack-changing process.