Dampening unit in offset printing press

摘要

It is desirable that ink and water be fully kneaded or distributed together when an inking unit 4 and a dampening unit 5 are in communication with each other. Accordingly, a dampening water communication path 17 which brings the inking unit 4 and the dampening unit 5 in and out of communication so that they can come in and out of contact with each other is provided, the dampening water communication path comprises a plurality of rollers including an oscillating roller 14 in rotational contact with an ink distributing roller 8 and an oscillating roller 16 in rotational contact with a dampening roller 10, and a roller interposed between them is a bridging roller 15 in rotational contact with one of these adjoining rollers and capable of coming in and out of contact with the other.

主权项

1. A dampening unit in an offset printing press in which a printing plate is furnished with ink by an inking unit comprising
an ink distributing roller, an ink oscillating roller and a plurality of inking rollers; said printing plate is furnished continuously with dampening water via a water fountain roller, a metering roller and a dampening roller; wherein all of the inking rollers present in said offset printing press are provided with the same one dampening water communication path adapted to supply and cease supplying the inking rollers with dampening water from the dampening roller, wherein said same one dampening water communication path comprises a plurality of rollers including:
a first oscillating roller in rotational contact with said ink distributing roller;a second oscillating roller in rotational contact with said dampening roller, said second oscillating roller is located downstream of a contact point between said dampening roller and said printing plate wherein said second oscillating roller is not in direct rotational contact with any of said plurality of the inking rollers provided in said inking unit, and at a location upstream of said contact point only the metering roller is in direct rotational contact with said dampening roller and the water fountain roller; anda roller interposed between the first oscillating roller and second oscillating roller is a bridging roller, the bridging roller being in rotational contact with one of the first oscillating roller and the second oscillating roller and capable of coming in and out of contact with the other one of the first oscillating roller and the second oscillating roller, wherein the first oscillating roller in the same one dampening water communication path is located downstream of a contact point between the dampening roller and the second oscillating roller, the first oscillating roller not being in rotational contact with the inking rollers, said inking rollers being in rotational contact with the printing plate.