US 4,064,801 A · Spray dampening system for offset printing

Abstract

The disclosed system controls through novel pressure and valving adjustment mechanisms the application of dampening fluid to the ink roll or offset plate on the plate cylinder of an offset printing press. In one embodiment the dampening fluid at a relatively high pressure passes through a pressure compensator which adjusts the fluid pressure in response to changes in the speed of the press. The fluid at the adjusted pressure is then directed to the spray bar of the system, where it is discharged through a plurality of spray nozzles controlled by a plurality of solenoid-actuated valves. In one embodiment, the valves continually fluctuate between open and closed positions, with the time of the fluctuations being adjustable in order to selectively and accurately meter the amount of dampening fuid applied to the offset plate on the plate cylinder of the press. In a second embodiment, the valves are adjustable and continuously open during spraying, and in a third embodiment the degree of opening of the valves is regulated in response to changes in the press speed and the pressure may be maintained at a manually adjustable level.

Claims16

Dependent claims

In a spray dampening system for delivering a dampening fluid to a rotating cylinder of a printing press;

a plurality of spray nozzles;
means supplying air under pressure to said nozzles to atomize and transport the dampening fluid to the printing press cylinder;
fluid delivery means for delivering dampening fluid to said nozzles, said fluid delivery means including first fluid regulating means for adjustably restricting the passage of dampening fluid through said fluid delivery means to said nozzles, second fluid regulating means for adjustably regulating the pressure of the fluid delivered to said nozzles by said fluid delivery means;
and regulator control means, comprising first sensing means for sensing the speed of the press, second sensing means for sensing the state of one of said fluid regulating means, and means operatively connected to said one fluid regulating means and responsive to said first and second sensing means for adjusting said one fluid regulating means in accordance with the speed of the press, whereby the flow of fluid to the nozzles may be adjustably regulated.

1 more element

In a spray dampening system for delivering a dampening fluid to a rotating cylinder of a printing press,

a plurality of spray nozzles;
means supplying air under pressure to said nozzles to atomize and transport the dampening fluid to the printing press cylinder;
fluid delivery means for delivering dampening fluid under pressure to said nozzles;
said fluid delivery means including valve means for adjustably restricting the passage of dampening fluid through said fluid delivery means to said nozzles, and said fluid delivery means further including pressure compensator means for adjustably regulating the pressure of the dampening fluid supplied to said valve means, said pressure compensator means comprising an adjustable pressure regulating valve having an adjustable control element, first sensing means for sensing the speed of the press, second sensing means for sensing the state of pressure adjustment of said pressure regulating valve, and compensator control means responsive to said first and second sensing means for adjusting the adjustable control element of said pressure regulating valve to increase the outflow pressure from said valve when the speed of the press increases and to decrease the outflow pressure when the speed of the press decreases.

1 more element

Dependencies are inferred from the claim text.

Spray dampening system for offset printing

Life of this patent

Spray dampening system for offset printing

Life of this patent

Abstract

Claims16