| 摘要 |
<p>The invention is a sheet feeder (10) including a skimmer (21), a bumper (68), a separator (19), and a guide plate (66, 81). The skimmer element (21) can be laterally reciprocated to assist in separation of the top sheet (44) from lower sheets in a stack (43). The bumper (68) extends across the feed path (14) and has a guide surface (84) positioned to confront the leading edges of the sheets (44) of the stack and direct the leading edge of an advancing engaged single sheet (44) away from the remainder of the stack (43). The separator (19) is designed for advancing the engaged sheet (44) while retarding any adjacent sheets. In one embodiment, a friction roller (34) and a stationary friction element (77) grip the engaged sheet between them. In another embodiment, the separator (19) has a driven advancing roller (34) nipped with a driven retarding roller (36) coupled to its drive (1605) by a friction clutch (1603). The clutch (1603) normally slips and permits the retarding roller (36) to be driven forward by the advancing roller(34). The clutch (1603) engages and drives the retarding roller (36) backward so long as a multifeed of two or more sheets is engaged between the advancing and retarding rollers (34, 36). The guide plate (66, 81) extends between the skimmer (21) and the separator (19), preventing the sheet from buckling.</p> |
