Device for flat objects with a power synchronizer several engines

A flat object feeder comprises an unstacking device (4), a conveyor (5) wherein the edge of objects are moved in series with a constant pitch and a synchronizing device (6) interposed between the device unstacking and the conveyor to compensate for variations in the pitch between consecutive objects. The unstacking device (4) is controlled to unstack a current object in response to a detection signal from the passage of another unstacked object preceding said current object downstream from the unstacker. The synchronizing device (6) is arranged to move simultaneously several song on objects in series respective different speed profiles so as to compensate for variations of the pitch.