Method and apparatus for driving a bridge roller on a printing press
AssigneeSun Graphic Technologies, Inc.
InventorsSteve M. Garner, Max W. Hess
Life of this patent
Estimating the term…
Abstract
A printing press has a plate cylinder, an inking system and a dampening system. A bridge roller provides a path between the inking and dampening systems. The bridge roller is in contact with a dampening form roller, which in turn is in contact with the plate cylinder. The dampening form roller is driven by an arrangement that allows the dampening form roller to rotate at a differential speed with respect to the plate cylinder in order to clean hickies off of the plate cylinder. The speed of the bridge roller is controlled so as to provide a slip nip between the bridge roller and the dampening form roller and so as to control the ink-water balance, even when the dampening form roller is rotating at a differential speed.
Claims12
A method of operating a printing press, said press having a plate cylinder, an inking form roller, a dampening form roller, and a bridge roller, said dampening form roller and said inking form roller being in contact with a plate on said plate cylinder, said bridge roller being in contact with said dampening form roller and said inking form roller, comprising the steps of:
- a) rotating said plate cylinder at a first surface speed;
- b) rotating said dampening form roller at a second surface speed, said second surface speed being different from said first surface speed;
- c) while rotating said dampening form roller at said second surface speed, rotating said bridge roller at a third surface speed, said third surface speed being different than said second surface speed, wherein a slip nip is created between said bridge roller and said dampening form roller, whereby a slip nip is created between the dampening form roller and the bridge roller for maintaining an ink and water balance.
A printing press, comprising:
- a) a plate cylinder;
- b) means for rotating said plate cylinder at a first surface speed;
- c) an inking form roller in contact with said plate cylinder;
- d) a dampening form roller in contact with said plate cylinder;
- e) a bridge roller in contact with said dampening form roller and said inking form roller;
- f) means for rotating said dampening form roller at adjustable surface speeds relative to the first surface speed;
- and
- g) means for rotating said bridge roller at the first surface speed, whereby a slip nip is created between the dampening form roller and the bridge roller for maintaining an ink and water balance.
Dependencies are inferred from the claim text.