Control system for the sheet-feeding unit and sheet-presenting unit of a printing machine

US4121820A · kind A · utility

Assignee

• VEB Polygraph Leipzig, Kombinat fur Polygraphische Maschinen und Ausrustungen · DE

Inventors

• Karl-Heinz Forster · Dresden, DE
• Werner Lein
• Henner Hettmann · Coswig, DE

Key dates

• Filing date: Apr 7, 1977
• Grant date: Oct 24, 1978
• Expiry date: Apr 7, 1997

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B65H7/04
• WIPO field: Handling
• WIPO sector: Mechanical engineering

Abstract

The sheet-presenting unit presents received sheets to the printing instrumentality of the machine. The sheet-feeding unit feeds sheets to the sheet-presenting unit. The two units have activators which can be enabled and disenabled. The operator of the machine initiates a start signal. A sheet detector generates missing-sheet, skew-sheet and muliplee-sheet signals, indicating the condition of the sheet at the sheet-presenting unit. Enablement stages determine whether the activators for the feeding and presenting units are to be enabled or not. When the activators are enabled, the start signal is automatically extinguished. A logic circuit receives the start signal and the signals from the sheet detector. The logic circuit has pre-start-up and post-start-up modes of operation, corresponding to generation and termination of the start signal. In the pre-start-up mode, it permits the feeding-unit and presenting-unit activators to become enabled when it receives a missing-sheet signal, and also if it detects the concurrent absence of the several types of bad-sheet signals. In the post-start-up mode, it maintains the feeding-unit and presenting-unit activators enabled so long as it contin…