Device for detecting a sheet stack height in a tray

US6308951A · kind A · utility

Assignee

• NexPress Solutions LLC · US

Inventors

• Franz Allmendinger · Hirschaid, DE
• Joachim Buck · Laichingen, DE
• Jochen Graeber · Bissingen, DE
• Volker H. Koenig · Großenhain, DE
• Heinz Michels · Wolfschlugen, DE

Key dates

• Filing date: Jan 27, 1999
• Grant date: Oct 30, 2001
• Expiry date: Jan 27, 2019

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B65H2555/24
• WIPO field: Handling
• WIPO sector: Mechanical engineering

Abstract

The invention relates to a device (1) for detecting a stack height of sheets (21) stacked in an input and/or output tray (2) of an apparatus, said device comprising a feeler (10) cyclically controlled and driven by means of a drive unit (12) and a control unit toward the sheet stack (21) in the stacking direction into a sensing position, and a sensor (11) detecting the sheet stack height and recognizing the sensing position of the feeler. To create a device which on the one hand has a simple, compact design along with freely selectable measurement steps and high measurement accuracy at each stack height, and on the other hand allows quiet and vibration-free operation, a controllable stepping motor (120) is provided, by means of which the feeler (10) is movable from a predeterminable initial position (y, z') toward the sheet stack (21) and into the sensing position (y', z), such that the stack height can be determined on the basis of the number of motor steps detected from the initial position until the sensing position of the feeler is recognized.