Distortion-reduced lithographic printing press
AssigneesHeidelberger Druckmaschinen AG, Heidelberg Harns, Inc.
InventorsJames B. Vrotacoe, Charles D. Lyman, Edward E. Urquhart
Life of this patent
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Abstract
In a lithographic printing press for printing on material in sheet or web form, a plate cylinder has a printing form mounted thereon. A gapless blanket cylinder is engageable with the plate cylinder and a tubular, removable blanket having a continuous surface is mounted on the blanket cylinder. Mechanisms to expand a cylindrical sleeve are provided as well as mechanisms to reduce cylinder distortion during rotation.
Claims17
A printing unit cylinder having reduced susceptibility to thermal distortion, for use in a lithographic printing press, comprising:
- a cylinder body having an outer surface and a central axis, a first width of the cylinder body for supporting a removable sleeve shaped element, the cylinder body including:
- a gas passage extending generally parallel to the central axis of the cylinder body, the gas passage extending substantially across the first width;
- a gas inlet disposed in the cylinder body and connecting the gas passage with the outer surface of the cylinder body;
- an inner compartment isolated from the gas passage, the inner compartment having a second width substantially equal to the first width, the inner compartment containing a fluid and reducing thermal distortion by maintaining a substantially uniform and constant temperature level around the circumference of the cylinder;
- a penetration disposed in the cylinder body and connecting the inner compartment with the outer surface of the cylinder body to permit the inner compartment to be charged with the fluid;
- and
- a blow off aperture disposed in the outer surface of the cylinder body and in fluid communication with the gas passage, for conducting gas to the outer surface of the cylinder body in order to facilitate the installation and removal of the sleeve-shaped element.
A lithographic printing press for printing on material in sheet or web form, comprising:
- a printing cylinder having a printing form removably mounted thereon;
- a blanket cylinder having a gapless sleeve-shaped blanket removably mounted thereon, the blanket cylinder having a central axis and a blanket supporting surface, the blanket supporting surface having a first width, the blanket cylinder engageable with the printing cylinder and having at least one compartment, the at least one compartment having a second width substantially equal to the first width, the at least one compartment containing a fluid and reducing thermal cylinder distortion by maintaining a substantially uniform and constant temperature level around the circumference of the blanket cylinder;
- an expansion mechanism disposed in the blanket cylinder for expanding the blanket to facilitate its installation and removal, the expansion mechanism extending generally parallel to the central axis of the blanket cylinder and substantially across the first width.
Dependencies are inferred from the claim text.