Vacuum printing cylinder construction
US4056057A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 27, 1976 |
| Grant date | Nov 1, 1977 |
| Priority date | — |
| Expiry date | Feb 27, 1996 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB41F27/1212
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
An improved form of vacuum-operated printing cylinder for a printing press, providing a practical means for holding the printing plate on the cylinder by vacuum alone. The cylinder comprises a hollow supporting shaft forming a pre-evacuation chamber. A plurality of axially spaced support rings are secured to the shaft and support a hollow cylinder sleeve. The cylinder sleeve, support rings and shaft form a hollow printing cylinder structure having a plurality of vacuum chambers. Each of the vacuum chambers is provided with independently valved air passage means for communication between the chamber and the pre-evacuation chamber. The cylinder sleeve is provided with a plurality of appropriately distributed radial passages for vacuum communication between the vacuum chambers and the exterior surface of the printing cylinder. The pre-evacuation chamber is connected by piping to a vacuum source and kept evacuated. To particular advantage, the vacuum effect of the pre-evacuation chamber can be immediately applied to the cylinder surface, by opening the appropriate valves, to effect a preliminary gripping of the printing plate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.