| 摘要 |
<p>In the preferred form, the cylinder includes a supporting shaft mounting, between its bearing portions, cylinder support rings. A cylinder sleeve is supported by the rings and forms, together with the rings and the supporting shaft, a hollow cylinder structure having vacuum chambers. The interior of the cylinder can be evacuated from one end of the shaft, and independently controllable valves are built into the cylinder, to enable the chambers to be independently evacuated. In one form of the invention, the cylinder sleeve has a large number of radial passages, providing communication to the outside surface of the cylinder. In another form, the sleeve has axially spaced, continuous annular grooves, which communicate at one or more places with the interior of the cylinder. The continuous grooves are blocked off at one or more places around the circumference of the cylinder to avoid leakage at the end-to-end discontinuity in a printing plate supported on the cylinder.</p> |
