Variable cutoff printing unit with belt blanket and method of printing
View Patent ↗A variable cutoff printing press is provided. The variable cutoff printing press includes a first plate cylinder, a second plate cylinder, a continuous belt blanket contacting the first and second plate cylinders and a movable support cylinder supporting the belt blanket. The first and second plate cylinders, the continuous belt blanket and the movable support cylinder form a first print section and the movable support cylinder is movable to change the print length of the first print section. A method of printing images with a printing press is also provided.
1. A method of printing images with a printing press comprising:
transferring a first image from a first plate cylinder to a belt blanket at a first location;
moving the belt blanket so the first location of the belt blanket passes by a second plate cylinder without the second plate cylinder printing on the first image;
transferring a second image from the second plate cylinder to the belt blanket at a second location directly adjacent to the first location; and
printing the first and second images from the belt blanket to a web.
2. The method of printing images with a printing press recited in claim 1 further comprising:
varying the length of the first and second images transferred to the belt blanket;
varying the length of the belt blanket according to the varied length of the first and second images by moving a movable support cylinder;
printing the first and second images of the varied length on the web.
3. The method of printing images with a printing press recited in claim 2 wherein varying the length of the belt blanket includes removing the belt blanket and replacing the belt blanket with a replacement belt blanket of a length that is different from a length of the belt blanket and moving the movable support cylinder to accommodate the length of the replacement belt blanket.
4. The method of printing images with a printing press recited in claim 2 wherein varying the length of the belt blanket includes stretching the belt blanket by moving the movable support cylinder.
5. The method of printing images with a printing press recited in claim 2 wherein varying the length of the first and second images transferred to the belt blanket includes removing a first plate from the first plate cylinder and replacing the first plate with a first replacement plate of a first replacement length that is different from a first length of the first plate and removing the second plate from the second plate cylinder and replacing the second plate with a second replacement plate of a second replacement length that is different from a second length of the second plate.
6. The method recited in claim 1 further comprising:
transferring the first image from the first plate cylinder to the belt blanket at a third location directly adjacent to the first location;
moving the belt blanket so the third location of the belt blanket passes by the second plate cylinder without the second plate cylinder printing on the first image; and
transferring the second image from the second plate cylinder to the belt blanket at a fourth location directly adjacent to the third location.
7. The method of printing images with a printing press recited in claim 6 further comprising varying the velocity of the first plate cylinder after the first image is transferred to the belt blanket at the first location and before the first image is transferred to the belt blanket at the third location and varying the velocity of the second plate cylinder after the second image is transferred to the belt blanket at the second location and before the second image is transferred to the belt blanket at the fourth location.