Printing unit having an idle throw-off configuration and a blanket changing throw-off configuration and corresponding printing press

A printing unit for printing a web of paper comprising:

• a frame;
• an upper printing group and a lower printing group, the upper printing group including an upper blanket cylinder and upper plate cylinder, the lower printing group including a lower blanket cylinder and a lower plate cylinder;
• a throw-off actuator moving the printing into at least one throw-on configuration, an idle throw-off configuration, a blanket-changing throw-off configuration and a plate-changing throw-off configuration, and
• a controller for controlling the movement of the throw-off actuator to move the upper and lower blanket cylinder and the upper and lower plate cylinder into the at least one throw-on configuration wherein the upper blanket cylinder is pressed against the lower blanket cylinder and the upper and lower blanket cylinders are pressed against the upper and lower plate cylinders respectively,
• the idle throw-off configuration wherein the upper blanket cylinder is spaced apart from the lower blanket cylinder, and the upper and lower blanket cylinders are spaced apart from the upper and lower plate cylinders respectively, so a web of paper printed by another printing unit passes through the print unit in a space between the upper and lower blanket cylinder without contacting any cylinder in the print unit,
• the blanket-changing throw-off configuration wherein the upper blanket cylinder is spaced apart from the lower blanket cylinder and the upper and lower blanket cylinders are spaced apart from the upper and lower plate cylinders respectively, the blanket-changing throw-off configuration being different from the idle throw-off configuration, and
• the plate-changing throw-off configuration wherein the upper blanket cylinder is spaced apart from the lower blanket cylinder, the upper and lower blanket cylinders are pressed against the upper and lower plate cylinders respectively, and a web of paper printed by another printing unit passes through a space between the upper and lower blanket cylinders, wherein
• in the blanket changing configuration, the upper blanket cylinder is moved upwards with respect to a position the upper blanket cylinder occupied in the at least one throw-on configuration and the lower blanket cylinder is moved downwards with respect to a position the lower blanket cylinder occupied in the at least one throw-on configuration, so a web of paper printed by another printing unit passes through the print unit in a space between the upper and lower blanket cylinders without contacting any cylinder in the print unit.

A printing press comprising:

• an unwinding device for unwinding a web;
• at least one print unit downstream of the unwinding device, the at least one print unit including:
• an upper printing group having an upper blanket cylinder and an upper plate cylinder;
• a lower printing group having a lower blanket cylinder and a lower plate cylinder;
• and
• a throw-off device moving the printing unit into at least one throw-on configuration, an idle throw-off configuration and a blanket-changing throw-off configuration, and a plate-changing throw-off configuration, the blanket-changing throw-off configuration being different from the idle throw-off configuration;
• and
• a folding device downstream of the at least one print unit;
• a controller for controlling the movement of the throw-off device to move the upper blanket and plate cylinders and the lower blanket and plate cylinders into the at least one throw-on configuration, wherein the upper blanket cylinder is pressed against the lower blanket cylinder and the upper and lower blanket cylinders are pressed against the upper and lower plate cylinders respectively,
• the idle throw-off configuration wherein the upper blanket cylinder is spaced apart from the lower blanket cylinder, and the upper and lower blanket cylinders are spaced apart from the upper and lower plate cylinders respectively, so a web of paper taut between an unwinding device placed upstream of the printing unit and the folding device placed downstream of the printing unit which is printed by another printing unit downstream of the unwinding device and upstream of the printing unit passes through the print unit in a space between the upper and lower blanket cylinder without contacting any cylinder in the print unit,
• the blanket-changing throw-off configuration wherein the upper blanket cylinder is spaced apart from the lower blanket cylinder and the upper and lower blanket cylinders are spaced apart from the upper and lower plate cylinders respectively, the blanket-changing throw-off configuration being different from the idle throw-off configuration, and
• the plate-changing throw-off configuration wherein the upper blanket cylinder is spaced apart from the lower blanket cylinder, the upper and lower blanket cylinders are pressed against the upper and lower plate cylinders respectively, and a web of paper printed by another printing unit passes through a space between the upper and lower blanket cylinders, wherein
• the web of paper passing through the at least one printing unit in a space between the upper and lower blanket cylinders without contacting any cylinder in the print unit when the print unit is in the idle throw-off configuration and the blanket-changing throw-off configuration.