Multicolor offset press with segmental impression cylinder gear

摘要

A low cost press able to print high quality continuous tone color copies comprises a single large diameter impression cylinder rotatably mounted to the machine frame. A plurality of print stations are spaced around the impression cylinder, each print station including a blanket cylinder in rolling contact with the impression cylinder and a plate cylinder in rolling contact with the blanket cylinder, the diameters of all of said plate and blanket cylinders being substantially the same and said impression cylinder having a diameter that is the same as or an even number more than the product of the plate cylinder diameter multiplied by the number of plate stations in the press. The cylinders are all rotatably coupled together by correspondingly sized gears so that they all rotate in unison with the impression cylinder gear being composed of arcuate parallel-cut segments having identical tooth profiles.