Offset printing machine for variable printing sizes with automatic loading and unloading of the printing cylinders

A web-fed offset printing machine for variable operating sizes, comprising:

• at least one printing unit formed of a fixed frame having plate, blanket, and counter printing cylinders arranged substantially vertically with the plate cylinder in a top position, the frame being designed to accommodate the cylinders with varying diameters for varying printing sizes;
• an upper movable cassette receivable on the fixed frame and having an inking station with a corresponding ink well, dipping rollers, distributing rollers, and inking rollers, means being provided for locating the cassette at a lower position in which the inking rollers can be in contact with a plate cylinder of a desired minimum size and an upper position in which the inking rollers are sufficiently set off from the plate cylinder to enable loading and unloading of the plate cylinder, blanket cylinder, and counter cylinder of a desired maximum size;
• and
• movable means on both sides of the fixed frame for engagement with respective opposite ends of a central shaft of the cylinders on the printing unit for unloading the printing unit cylinders and placing them on supporting bars situated in a downstream vicinity of the printing unit and for loading different sized cylinders from the supporting bars onto the printing unit.