Abstract: A sheet feeder for sheet-processing machines having a positively driven, gripping mechanism which travels over at least two deflection wheels including at least one sheet-transporting gripper which is opened or closed during the course of travel through a revolving path. A number of toothed belts can be used; each belt includes a plurality of spaced aparet recesses into which a support body carrying a gripper mechanism is removably inserted. The deflection wheels are provided with circumferential recesses which correspond to an inwardly protruding part of the support body of the gripper mechanism in the form of an actuating lever that is actuated on striking or leaving a cam race, which may be part of the circumferential recesses of the deflection wheels.

Abstract: A sheet feeder and invertor apparatus for sheet-processing machines for selective operation with or without inversion, preferably for two offset printing machines arranged in tandem. According to the invention, two conveyor belt arrangements, such as invertor apparatus 50 and belt conveyor 26, extend parallel to one another and are disposed one above the other, so that the adjacent runs of these two belt arrangements form a gap (35), in which the sheets can be fed by the belt conveyor (26) from one machine (3) toward another machine (5). Sheet grippers (58) are disposed on the belt (56) of the invertor apparatus (50), closing in the vicinity of the run remote from the belt conveyor (26) and opening in the vicinity of the run oriented toward the belt conveyor (26).