Offset printing device for a rotary mchine printing machines

摘要

An offset printing system includes an improved inking unit for applying ink to a rotatable plate cylinder, wherein the inking unit appreciably reduces the production of contaminants. In particular, the inking unit one or more ink application rollers that adjacently contact the plate cylinder. A series of rollers are in ink communication with these application rollers, including at least one inking roller in direct contact with the ink application rollers, and at least one inking roller in indirect inking communication with the ink application rollers. The inking rollers are driven in a positively locking manner and which are drivable at a peripheral speed that differs from the peripheral speed of the plate cylinder, and the inking roller furthest from the plate cylinder is driven with the greatest peripheral speed differential relative to the plate cylinder. This peripheral speed differential between rollers results in a relative slippage and wiping effect which advantageously reduces the effect of contaminants.