| 摘要 |
This invention concerns a film dampener unit for offset printing presses, with a dampening medium container in which a constant level of dampening medium is maintained, and with a dampener ductor or pan roller dipping into the dampening medium and transferring the dampening medium as a film onto at least one form roller which contacts the printing plate on the plate cylinder, whereby the thickness of the dampening medium film is determined by a metering roller which engages the dampener ductor roller surface in its rotary motion before the same engages the form roller. In order to reduce the number of rollers required for a flexibly operating dampener unit, the dampener ductor of this invention also functions as a dampener vibrator or oscillating ductor, having in addition to a rotation drive, another drive mechanism which effects an axial back and forth or reciprocating movement. |
