Offset litho conversion from letterpress equipment
US4423681A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 11, 1982 |
| Grant date | Jan 3, 1984 |
| Priority date | — |
| Expiry date | Feb 11, 2002 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S101/49
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
Web letterpress equipment is converted to offset lithographic equipment by modification of a driven letterpress impression cylinder to receive an offset blanket, thereby producing an offset blanket cylinder. A letterpress plate cylinder is modified to become an offset plate cylinder with accompanying offset inking and dampening equipment. In one embodiment, a driven letterpress plate cylinder of a color hump is packed to become an offset impression cylinder cooperating with the offset blanket cylinder. In a second embodiment, the letterpress plate cylinder of the color hump is modified to an offset color plate cylinder and a driven offset impression cylinder is added to cooperate with the offset printed on one side of a web. When used in combination with similarly converted letterpress plate, impression and color hump plate cylinders, at least three colors may be offset printed on one side of a web or multiple colors printed on opposite sides thereof. The press tower is rewebbed to print with proper registration in the bight between the respective offset blanket cylinders and offset impression cylinders.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.