International Business Machines Corporation

Sherwood Anderson Clay

Richard A Lamos

Michael K Bullock

Gregory Bingham Overton

A normal force applicator and removal apparatus which applies, varies and removes force applied to the top of a document stack where documents are being fed, i.e., by a shingler wheel type document feeder, (also termed combing wheel or wave generator) in order to generate a shingled stack of documents for subsequent processing. The shingler wheel is adjustable so that it can be centered for document stacks of multiple lengths. In order to shingle documents at a practical and predictable rate, i.e., maintain a shingled stack of documents, and to avoid skewing of the documents as they are shingled, the normal force is varied as a function of the thickness of the document stack decreasing as the document stack is depleted, and the normal force is applied symmetrically from the center of the shingler wheel to either side thereof. This symmetrical force distribution is maintained throughout the range of adjustment of the shingler wheel.

Apparatus for applying, varying and removing a normal force in a

A dual exit tray xerographic machine, having a hot roll fuser, supplies its output copy sheets to a large-capacity exit pocket whereat the sheets are stacked in a vertically extending pile, on a servo-movable elevator platform. The platform height is servo controlled so as to maintain the stack's top sheet at a fixed position relative to a fixed-position, generally horizontally extending, sheet discharge path. Sheet stacking is enhanced by a pair of movable bars. A hold-down bar, in its quiescent position, presses the stack's trailing edge portion down to insure reliable insertion of the next sheet. A pusher bar is maintained in an elevated quiescent position during such insertion. After the sheet has been inserted, the pusher bar lowers onto the stack, at a position between the hold-down bar and the stack's leading edge. The pusher bar thus holds the just-inserted sheet down. The hold-down bar synchronously moves in a generally elliptical path, to first clear the trailing edge of the just-inserted sheet. The hold-down bar then moves in an upward path until it again overlies the stack's trailing edge. The hold-down bar now descends onto the stack, as the pusher bar returns to its quiescent position.

Growing community of inventors

Boulder, CO, United States of America

Sherwood Anderson Clay