PURPOSE: To move a rubber blanket cylinder automatically by two-stage operations by using a two-stroke air cylinder for the rotary cylinder of an eccentric metal in the cylinder attaching and removing device of an offset press.

CONSTITUTION: In a cylinder attaching and removing device 20, a rod 21, which is supported with an eccentric inner metal 28 whose one end is attached to a rubber blanket cylinder B, and a two-stroke air cylinder Y are linked through a lever 24. When the rubber blanket cylinder B is separated from a plate cylinder C and a pressure cylinder A, the two-stroke cylinder Y is operated by the command from a detecting device. Supporting shafts 26 and 23 of the lever 24 are moved from a point (c) to a point (b), and the two-stroke cylinder Y is once stopped. A supporting shaft 22 of the eccentric inner metal 28 is moved from a point (c) to a point (b) through the rod 21 by the movement of the lever 24. Thus the rubber blanket cylinder B can be separated from the plate cylinder C. After the stop, the two-stroke cylinder Y is operated again, and the supporting shafts 26 and 23 of the lever 24 are moved from the point (b) to a point (a). The supporting shaft 22 of the eccentric inner plate 28 is moved from the point (b) to a point (a) through the rod 21. Thus, the rubber blanket cylinder B can be also separated from the pressure cylinder A.