Patent ID: 8141489
Filing Date: 2012-03-27
Classification: B41F,B41M

Abstract:
1. A variable cutoff printing unit comprising: a first upper plate cylinder carrying a first upper image; a first upper blanket cylinder including a first upper blanket print area for transferring the first upper image to a web and a first upper blanket non print area; a second upper plate cylinder carrying a second upper image; and a second upper blanket cylinder including a second upper blanket print area for transferring the second upper image to the web and a second upper blanket non print area; a first lower plate cylinder carrying a first lower image; a first lower blanket cylinder including a first lower blanket print area for transferring the first lower image to the web and a first lower blanket non print area; a second lower plate cylinder carrying a second lower image; a second lower blanket cylinder including a second lower blanket print area for transferring the second lower image to the web and a second lower blanket non print area; at least one first motor driving the first upper blanket cylinder and the first lower blanket cylinder at varying velocities during each revolution; and at least one second motor driving the second upper blanket cylinder and the second lower blanket cylinder at varying velocities during each revolution; wherein the first upper blanket non print area, the second upper blanket non print area, the first lower blanket non print area and the second lower blanket non print area move at a surface speed different than a speed of the web while passing the web during printing; wherein the first upper image and the second upper image form one continuous upper image having an upper cutoff length; wherein axes of the first upper plate cylinder, the first upper blanket cylinder, the first lower blanket cylinder, the first lower plate cylinder, the second upper plate cylinder, the second upper blanket cylinder, the second lower blanket cylinder and the second lower plate cylinder are stationary as the first upper blanket cylinder and the first lower blanket cylinder are driven at varying velocities during each revolution and as the second upper blanket cylinder and the second lower blanket cylinder are driven at varying velocities during each revolution.