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US 2002/0053294 A1Published application
Dual-web offset printing press and method for printing dual webs
AssigneeHeidelberger Druckmaschinen AG
InventorJOHN SHERIDAN RICHARDS
Life of this patent
Estimating the term…
Abstract
A web offset printing press for dual webs includes several printing units, each printing a color image on outer sides of a pair of webs. The webs travel through these printing units in a back-to-back arrangement. Additional printing units print another color image on the outer side. The webs may be separated during this process, with a pair of printing couples used for each web, so that one couple may print the additional image while the plate of the other is changed. The additional printing units also print a single-color image on the opposite side of each web.
Claims23
A printing unit for printing two webs, comprising:
- a first blanket cylinder;
- a first plate cylinder, the first plate cylinder being selectively movable between a contacting position in which the first plate cylinder contacts the first blanket cylinder and an off-impression position in which the first plate cylinder is remote from the first blanket cylinder;
- and
- an opposing cylinder, the opposing cylinder being one of an impression cylinder and a second blanket cylinder, the first blanket cylinder and the opposing cylinder being arranged to form a nip therebetween, the first blanket cylinder and the opposing cylinder maintaining the nip when the first plate cylinder is in the off-impression position.
1 more element
A printing press for printing two webs simultaneously, comprising:
- a first blanket cylinder;
- a second blanket cylinder, the first and second blanket cylinders being arranged to form a two-web nip;
- a first plate cylinder associated with the first blanket cylinder, the first plate cylinder being selectively moveable between a first contacting position in which the first plate cylinder contacts the first blanket cylinder and a first off-impression position in which the first plate cylinder is remote from the first blanket cylinder;
- and
- a second plate cylinder associated with the second blanket cylinder, the second plate cylinder being selectively movable between a second contacting position in which the second plate cylinder contacts the second blanket cylinder and a second off-impression position in which the second plate cylinder is remote from the second blanket cylinder, the first and second blanket cylinders maintaining the two-web nip regardless of the positions of the first and second plate cylinders;
- a third blanket cylinder;
- an opposing cylinder, the opposing cylinder being one of a fourth blanket cylinder and an impression cylinder, the opposing cylinder and the third blanket cylinder being arranged to form a first one-web nip;
- and
- a third plate cylinder, the third plate cylinder being selectively movable from a third contacting position in which the third plate cylinder contacts the third blanket cylinder and a third off-impression position in which the third plate cylinder is remote from the third blanket cylinder, the third blanket cylinder and the opposing cylinder maintaining the first one-web nip regardless of the position of the third plate cylinder.
6 more elements
A method of changing a plate on a plate cylinder of a two-web printing press on the fly, the two web printing press including a first plate cylinder, a first blanket cylinder contacting the first plate cylinder, and a second blanket cylinder, the first and second blanket cylinders forming a nip therebetween, at least one of a pair of webs traveling through the nip at a selected speed, comprising the steps of:
- (a) separating a the first plate cylinder from the first blanket cylinder;
- (b) slowing the first plate cylinder to a stop;
- (c) replacing a printing plate on the first plate cylinder with a first replacement plate;
- (d) accelerating the first plate cylinder to synchronize the first plate cylinder with the first blanket cylinder;
- and
- (e) placing the first plate cylinder in contact with first blanket cylinder.
3 more elements
A printing press comprising:
- a first printing unit including a first nip formed between first and second blanket cylinders, a second nip formed between the first blanket cylinder and a first plate cylinder and a third nip formed between the second blanket cylinder and a second plate cylinder, wherein first and second webs are fed back-to-back through the first nip of the first printing unit so that a first side of the first web contacts the first blanket cylinder and a first side of the second web contacts the second blanket cylinder, the first plate cylinder being movable between a first cylinder contacting position in which the first plate cylinder contacts the first blanket cylinder to form the second nip of the first printing unit and a first cylinder off-impression position in which the first plate cylinder is separated from the first blanket cylinder, and the second plate cylinder being movable between a second cylinder contacting position in which the second plate cylinder contacts the second blanket cylinder to form the third nip of the first printing unit and a second cylinder off-impression position in which the second plate cylinder is separated from the second blanket cylinder;
- a second printing unit including a first nip formed between first and second blanket cylinders, a second nip formed between the first blanket cylinder and a first plate cylinder and a third nip formed between the second blanket cylinder and a second plate cylinder, wherein only the first web is fed to the first nip of the second printing unit so that the first side of the first web contacts the first blanket cylinder and a second side of the first web contacts the second blanket cylinder, the first plate cylinder being movable between a first cylinder contacting position in which the first plate cylinder contacts the first blanket cylinder to form the second nip of the second printing unit and a first cylinder off-impression position in which the first plate cylinder is separated from the first blanket cylinder;
- and
- a third printing unit including a first nip formed between first and second blanket cylinders, a second nip formed between the first blanket cylinder and a first plate cylinder and a third nip formed between the second blanket cylinder and a second plate cylinder, wherein only the second web is fed to the first nip of the third printing unit so that the first side of the second web contacts the first blanket cylinder and a second side of the second web contacts the second blanket cylinder, the first plate cylinder being movable between a first cylinder contacting position in which the first plate cylinder contacts the first blanket cylinder to form the second nip of the third printing unit and a first cylinder off-impression position in which the first plate cylinder is separated from the first blanket cylinder.
1 more element
A printing press, comprising:
- a dual-web printing unit including a dual-web nip, the dual-web printing unit receiving first and second webs, the first and second webs traveling back-to-back through the dual-web nip;
- a fist single-web printing unit including a first single-web nip, the first single-web printing unit receiving the first web, the first web traveling through the first single-web nip;
- and
- a second single-web printing unit including a second single-web nip, the second single-web printing unit receiving the second web, the second web traveling through the second single-web nip;
- wherein first and second plate cylinders of the dual-web printing unit, a first plate cylinder of the first single-web printing unit, and a first plate cylinder of the second single-web printing unit may each be selectively taken off impression without interrupting movement of either of the first and second webs through any of the nips;
- wherein an outer side of the first web selectively receives a first color image from at least one of a first blanket cylinder of the dual-web printing unit and a first blanket cylinder of the first single-web printing unit;
- wherein an inner side of the first web receives a second color image from a second blanket cylinder of the first single-web printing unit;
- wherein an outer side of the second web selectively receives the first color image from at least one of a second blanket cylinder of the dual-web printing unit and a first blanket cylinder of the second single-web printing unit;
- and
- wherein an inner side of the second web receives the second color image from a second blanket cylinder of the second single-web printing unit.
7 more elements
Dependencies are inferred from the claim text.