Automatic document feeder

A document processing apparatus comprising a document processing section, a single sheet separator having a stack receiving nip and an automatic document feeder wherein said automatic document feeder comprises:

• a) a pre-pick roller support shaft having spaced shaft 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 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.