| abstract |
A dampening system has a pan 21 for containing dampening fluid 22, and transfer 23 and metering rollers 25 for bringing dampening fluid up out of the pan. A transition roller 27 contacts one of the transfer and metering rollers. The transition roller is movable between first and second positions. In the first position, the transition is off of the plate cylinder 11 and dampening fluid is applied to the plate cylinder by ink form rollers 17. In the second position, the transition roller is on the plate cylinder. Another version of the dampening system has a bridge roller 29 between the transition roller and a ink form roller, which bridge roller is movable between third and fourth positions. In the third position, the bridge roller is on the transition roller. In the fourth position, the bridge roller is off of the transition roller. The dampening system can dampen the plate cylinder without the use of alcohol. The transition roller is rotated by a separate motor so that its speed is controlled independently of the other rollers. When the transition roller is on the plate cylinder, it can be slowed down to clean hickeys off of the plate cylinder. When the plate cylinder is clean, it can be moved off of the plate cylinder or speeded up to the same speed as the plate cylinder. A controller is provided to automatically adjust the amount of dampening fluid being applied to the plate cylinder by regulating the speed of the transfer and metering rollers. |