Multicolor offset press with segmental impression cylinder gear

Printing apparatus comprising a machine frame;

• a relatively large diameter first cylinder rotatably mounted to the frame;
• a circular gear coaxially fixed to said first cylinder, said gear having a diameter that is substantially the same as that of the first cylinder and being composed of a plurality of separate arcuate segments, the corresponding teeth of all of said gear segments having substantially identical tooth profiles having been cut in parallel simultaneously by the same gear cutting tool, each said gear segment defining a printing sector of said first cylinder;
• a plurality of substantially identical second cylinders rotatably mounted to said frame in rolling contact with said first cylinder at spaced-apart locations around the first cylinder;
• a corresponding plurality of second cylinder gears coaxially fixed to said second cylinders, said second cylinder gears having the same diameter as said second cylinders and being in mesh with said circular gear, the arc length of each of said circular gear segments being equal to the circumferences of said second cylinder gears.

Printing apparatus comprising a frame;

• a relatively large diameter first cylinder rotatably mounted to said frame;
• a first circular gear coaxially fixed to said first cylinder for rotation therewith, said first gear having essentially the same diameter as said first cylinder and being composed of a plurality of separate arcuate sectors the corresponding teeth of all of said sectors having identical tooth profiles having been cut in parallel simultaneously by the same gear cutting tool;
• at least one second cylinder rotatably mounted to said frame in rolling engagement with said first cylinder;
• at least one second circular gear coaxially fixed to said at least one second cylinder for rotation therewith, said at least one second gear having the same diameter as said at least one second cylinder and being in mesh with said at least one first gear;
• at least one imagable third cylinder rotatably mounted to said frame, said at least one imagable third cylinder having the same diameter as, and being in rolling engagement with, said at least one second cylinder and at least one third circular gear coaxially fixed to said at least one third cylinder for rotation therewith, said at least one third gear having the same diameter as, and being in mesh with, said at least one second gear, the arc length each of said first gear sectors being equal to the circumference of each of said at least one second and third gears.

Printing apparatus comprising

• a machine frame;
• an impression cylinder rotatably mounted to the frame;
• at least one print station positioned opposite the impression cylinder, each print station including a blanket cylinder rotatably mounted to the frame for rolling contact with the impression cylinder, a plate cylinder rotatably mounted to the frame for rolling contact with the blanket cylinder and means for applying image dots to a plate supported by the plate cylinder;
• means for rotating said cylinders in unison;
• means for applying ink to said plate;
• ink regulating means responsive to ink control signals for regulating the amount of ink applied to the plate by the ink applying means at each print station;
• and
• control means responsive to picture signals for actuating the image applying means at each print station to form on said plate a corresponding image comprised of dots, said control means counting the number of image dots to be formed by each print station on selected portions of said plate and controlling the ink regulating means for that print station based on the number of dots to be printed by that print station on said plate portions.

Printing apparatus comprising

• a machine frame;
• an impression cylinder rotatably mounted to the frame;
• at least one print station positioned opposite the impression cylinder, each print station including equal diameter plate and blanket cylinders, rotatably mounted to said frame parallel to the impression cylinder and means for imaging a plate supported on the plate cylinder, said cylinders having correspondingly sized coaxial meshing gears for rotating said cylinders in unison, said impression cylinder gear being composed of a number of arcuate segments corresponding to the number of print stations, the arcuate length of each gear segment being equal to the circumferences of said plate and blanket cylinder;
• and
• means for rotating said cylinders.

Printing apparatus comprising

• a machine frame;
• an impression cylinder rotatably mounted to the frame;
• at least one print station positioned opposite the impression cylinder, each print station including equal diameter plate and blanket cylinders rotatably mounted to said frame parallel to the impression cylinder and means for imaging a plate supported on the plate cylinder, said cylinders having correspondingly sized coaxial meshing gears for rotating said cylinders in unison, said impression cylinder gear being composed of a number of arcuate segments corresponding to the number of print stations, the arcuate length of each gear segment being equal to the circumferences of said plate and blanket cylinder gears and said gear segments having corresponding teeth with substantially identical tooth profiles those teeth having been cut in parallel simultaneously by the same gear cutting tool;
• and
• means for rotating said cylinders.