Multi-color variable format offset printing press

Claim 1

In a multi-color offset printing press for variable formats for a printing continuous web selectively with and without `Caroll` type perforations, the printing press having a plurality of printing units, the improvement comprising in combination: a blanket bearing cylinder; a plate bearing cylinder; a pressure cylinder; mounting means for mounting the plate bearing cylinder in rotating contact with the blanket bearing cylinder and the blanket bearing cylinder in rotating contact with the pressure cylinder, with the web being drawn between the pressure cylinder and the blanket bearing cylinder; means for causing the blanket bearing cylinder to exert pressure against the plate bearing cylinder and the pressure cylinder; means for releasing the pressure exerted by the blanket bearing cylinder at the end of the format and on at least one printing cycle out of two; and means for driving the web and for stopping forward movement of the web when the pressure is released by the blanket bearing cylinder, to allow the web to be positioned correctly before the following printing cycle.