Web displacer for a printing unit
A printing press is provided which includes a printing unit for printing on a web. The printing unit includes a plate cylinder, a blanket cylinder, and an impression cylinder. The press further includes a web displacement bar movable between a first position in which the web displacement bar is spaced apart from a web passing between the blanket cylinder and the impression cylinder, and a second position in which the web displacement bar holds the web in contact with the impression cylinder and spaced apart from the blanket cylinder. A method of operating the press is also provided.
1. A printing unit for printing on a web, comprising:
a plate cylinder;
a blanket cylinder;
an impression cylinder;
a web displacement bar movable between a first position in which the web displacement bar is spaced apart from a web passing between the blanket cylinder and the impression cylinder, and a second position in which the web displacement bar holds the web in contact with the impression cylinder and spaced apart from the blanket cylinder; and
an actuator coupled to the web displacement bar, the actuator operable to move the web displacement bar between the first and second positions.
2. The printing unit of claim 1 , wherein the web displacement bar comprises an elongated rod that extends substantially across a length of the blanket cylinder.
3. The printing unit of claim 1 , wherein the web displacement bar comprises an elongated roller that extends substantially across a length of the blanket cylinder.
4. The printing unit of claim 1 , wherein the web displacement bar comprises a plurality of rollers that extend substantially across a length of the blanket cylinder.
5. The printing unit of claim 1 , wherein the web displacement bar is secured to the actuator, and wherein the actuator is secured to the printing unit.
6. The printing unit of claim 5 , wherein the actuator is secured to a blanket cylinder support of the printing unit.
7. The printing unit of claim 5 , wherein the actuator includes a pair of pneumatic cylinders.
8. The printing unit of claim 5 , wherein the printing unit is a variable cut-off printing unit, and wherein the actuator is secured to a movable blanket cylinder support of the printing unit.
9. A printing press for printing on a web, comprising:
a printing unit including a plate cylinder, a blanket cylinder, and an impression cylinder;
a web displacement bar movable between a first position in which the web displacement bar is spaced apart from a web passing between the blanket cylinder and the impression cylinder, and a second position in which the web displacement bar holds the web in contact with the impression cylinder and spaced apart from the blanket cylinder; and
an actuator coupled to the web displacement bar, the actuator operable to move the web displacement bar between the first and second positions.
10. The printing press of claim 9 , wherein the web displacement bar comprises an elongated rod that extends substantially across a length of the blanket cylinder.
11. The printing press of claim 9 , wherein the actuator includes a pair of pneumatic cylinders.
12. The printing press of claim 9 , wherein the printing unit is a variable cut-off printing unit, and wherein the actuator is secured to a movable blanket cylinder support of the printing unit.