| 摘要 |
A document feeding apparatus feeds a document (18) from the endmost position (22) of a stack of documents (10) into a document path (34) using a vacuum suction head operating through an aperture (36) in a baseplate (16). A vacuum source (38) attracts a document (18) to the suction head (40) during a return stroke (50). No vacuum is applied during a forward stroke (48). The vacuum source (38) comprises a reciprocal air pump (54,108) having a potential energy store (66,90) used to power a rapid vacuum-creating return stroke despite a low-power drive source (44,96) to power the forward stroke. A barrel-pump (54) or bellows device (108) can be used as the reciprocal air pump. The vacuum-creating return stroke can be initiated either by solenoid (78) release or by operation of a cam (98) beyond a first angular position. |
