Two plate cylinders have horizontal and transverse axes placed respectively on either side of a vertical plane passing by axes of a touching cylinder and a blanket cylinder. A support is mounted between the touching cylinder and the blanking cylinder and is provided for the two plate cylinders, being tiltably mounted about the axis of the blanket cylinder. Two starting cylinders have horizontal and transverse axes disposed respectively slightly below and outside with respect to each plate cylinder. Control means control a tilting motion of the support of the plate cylinders for setting under pressure each of the plate cylinders and for rotatively driving the starting cylinders.