Cylinder throw apparatus

A cylinder throw apparatus comprising:

• a plate cylinder having a circumferential surface on which a printing plate is mounted;
• a printing cylinder disposed to have a circumferential surface thereof kept away from said circumferential surface of said plate cylinder;
• a blanket cylinder disposed between said plate cylinder and said printing cylinder;
• and
• driving means for moving said blanket cylinder between an impression-on position in which said blanket cylinder is pressed against said plate cylinder and, through a paper sheet, pressed against said printing cylinder, and an impression throw-off position in which said blanket cylinder is kept away from said plate cylinder and said printing cylinder, and automatically setting a gap between said blanket cylinder and said printing cylinder at the impression-on position in correspondence with a paper thickness, wherein said driving means comprises one pair of eccentric bearings, pivotally provided to a left frame and a right frame, for supporting two ends of said blanket cylinder;
• and
• a control means for calculating a value indicating a moving amount of said blanket cylinder from the impression throw-off position to the impression-on position in correspondence with the input paper thickness, and for controlling an operating of said driving means on the basis of the calculated value,
• wherein moving the blanket cylinder between the impression-on and impression throw-off positions and adjusting the blanket cylinder to the printing cylinder for paper thickness are both performed by said one pair of eccentric bearings.