Feed rollers with reversing clutch

摘要

The invention is a sheet feeder for engaging and removing a sheet of paper or other material from a stack and feeding it along a path. The sheet feeder can include a sheet separator designed for advancing the engaged sheet while retarding any adjacent sheets. The separator has a driven advancing roller nipped with a driven retarding roller coupled to its drive by a friction clutch. The clutch normally slips and permits the retarding roller to be driven forward by the advancing roller when one or no sheets are engaged between the advancing and retarding rollers. The clutch engages and drives the retarding roller backward so long as a multifeed of two or more sheets is engaged between the advancing and retarding rollers.