Patent ID: 6457707
Filing Date: 2002-10-01
Classification: B65H

Abstract:
An automatic document feeder for moving a stack of individual sheets from a stack loaded position to a nip in a single sheet separator in a document processing apparatus comprising:a) a pre-pick roller support shaft having spaced support bearings thereon; b) a pre-pick roller rotatably supported on said shaft, said pre-pick roller having a sheet gripping surface thereon; c) a pressure plate resiliently biased toward said sheet gripping surface to urge a stack of sheets against said sheet gripping surface of said pre-pick roller; d) a stack stop rotatably mounted on said shaft, said stop having at least one finger moveable between a stack blocking position in which said finger contacts said pressure plate to move said pressure plate away from contact with said pre-pick roller and a stack transmitting position in which said finger no longer contacts said pressure plate; e) a source of rotary power connected to said shaft for rotating said pre-pick roller support shaft in a reverse reset direction and in a forward sheet delivery direction; said pre-pick roller support shaft and said pre-pick roller having mutually engageable drive stops thereon positioned such that said pre-pick roller is: (1) freely rotatable on said shaft during loading of a stack in contact with said pre-pick roller into engagement with said finger and when said shaft is driven in said forward direction to move said finger from an initial stack blocking position to a stack passing position; and (2) rotated by said rotating shaft during shaft rotation in said forward direction until a leading edge of said stack has reached said nip.