Abstract: A printing unit of a printing press includes at least two frame parts whose distance from each other can be varied. Each of these frame parts include two laterally spaced frame plates. The two frame plates in each of the frame parts accommodate at least one cylinder or roller which extends between them. The two lateral frame plates in each frame part are spaced from each other in an axial direction of the supported cylinder or roller. Adjacent ones of the frame parts are connectable to each other by abutting of their respective lateral frame plates. At least three locking and/or centering devices are used to align and to lock together the lateral frame plates of adjacent ones of the frame parts.

Abstract: A printing unit has at least one cylinder or roller which is mounted in a frame part that is movable by the use of rolls. The rolls are movable between a deployed position and a retracted position. In the deployed position, the rolls support the movable frame part. In the retracted position, the rolls, at least in part, no longer support the weight of the movable frame part, which is now supported, at least in part, on a stationary support by way of a contact area that is different from the rolls.

Abstract: A sheet register adjusting assembly of a register drum of a sheet fed rotary printing machine uses axial displacement of the register drum to provide later register adjustment, and pivotal displacement of the register drum to provide circumferential register adjustment. Both lateral and circumferential register adjustments may be made in an accurate manner.