摘要 |
The plate cylinder of a printing press is driven at a non-uniform speed to suit a particular repeat length of the web to be printed. If the repeat length is shorter or longer than the plate cylinder circumference, the plate cylinder is respectively accelerated or retarded from web speed between successive imprints by being connected to the output of differential gearing of which a first input is connected to a drive gear and a second input is connected to a gear oscillated by means of a cam follower of a cam rotating together with said drive gear. |