An apparatus for driving a pair of nip rollers at a variable rotational speed

摘要

An apparatus for driving a pair of nip rollers at a rotational velocity that varies within each revolution is provided. A first nip roller (30) and a second nip roller (31) form a nip therebetween for moving a sheet or signature. A drive configured and arranged to drive a drive shaft at a constant rotational speed. A pair of variable rotational speed couplings (1) each have an input coupled to the drive, and an output connected to a respective one of the first and second nip rollers. Each coupling rotates its respective nip roller at a rotational speed that varies within each revolution.