Apparatus for separating and conveying the uppermost sheet of a stack of sheets or sheet-like articles

US4759537A · kind A · utility

Assignee

• Fraunhofer-Gesellschaft zur förderung der angewandten Forschung e.V. · DE

Inventors

• Egon Illig · Stuttgart, DE
• Ernst Bergner · Fellbach, DE

Key dates

• Filing date: Mar 12, 1986
• Grant date: Jul 26, 1988
• Expiry date: Mar 12, 2006

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B65H3/0891
• WIPO field: Handling
• WIPO sector: Mechanical engineering

Abstract

In order to be able in a simple manner to supply one or more suction pick devices periodically moved relative to the surface of a stack with driving energy, the suction pick-up device is connected to an air volume or source having substantially constant negative pressure over overpressure, and a valve assembly that periodically connects the suction pick-up device to the outside air. The valve assembly is incorporated in the connecting line between the suction pick-up device and the air volume. The valve assembly may be embodied with a control piston that is subject to the action of a restoring force, by a pneumatic multi-way valve having a regulattable frequency, or by a magnetic valve connected to a regulattable frequency generator. With the aid of a regulating device for the cross section of the vent opening, it is possible to generate an amplitude of the suction pick-up device movement that becomes progressively smaller from stroke to stroke after the movable suction pick-up device has been switched on, until it attains a complete standstill.