Ricoh S-P3 Manual page 112

Clutch: Transfers drive from the main motor to the feed roller.
Cams on the feed roller shaft move the bottom plate up, and this
pushes the paper stack against the feed roller.
The cams release the bottom plate. Then, the bottom plate presses the stack of
paper against the feed roller. Then, the cams move the plate down to move the
stack away from the feed roller, to ensure that there is no double feed.
Feed
Clutch
112
M080 Training - Sincere-P3
Feed Roller
Cam