Ronald J Reese

US Patent:

47308230, Mar 15, 1988

Filed:

Nov 28, 1986

Appl. No.:

6/935886

Inventors:

Daniel A. Barela - Boulder CO
Mark A. Beran - Niwot CO
Louis A. Bustamante - Berthoud CO
Cecil M. McDonald - Longmont CO
Ronald E. Reese - Boulder CO
Roger D. Shepherd - Rollinsville CO

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

B65H 308

US Classification:

271 31

Abstract:

Sheet feeder having adaptive mechanism for assuring dependable automatic operation when the stack of sheets to be fed consists of sheets having varying thicknesses and weights. In a sheet feeder having pickers to move a document from the top of a stack of sheets supported by a moveable table to a feed-in position, the latter possibly including a vacuum belt for moving the document, sensors supply signals to indicate a sheet has been picked. After moving the pickers and table to initial positions, the controller moves the picker to a predetermined reference position. If a sheet is picked above or below the predetermined initial position, the position of the table is adjusted accordingly. In a second embodiment in a recirculating automatic sheet feeder, the table is initially positioned then after feeding the sheets from the stack once, it is initialized at a second predetermined position depending on the number of documents in the stack and on the position of the table prior to picking the documents a second time.