GB1019961A - Printing press water solution mixing and distributing mechanism - Google Patents

Abstract

1,019,961. Printing-apparatus; damping- apparatus. BALDWIN-GEGENHEIMER CORPORATION. Oct. 2, 1962 [Nov. 14, 1961], No. 37395/62. Heading B6C. The or each damping fountain pan of a rotary-offset printing machine is supplied with an " etch and gum " solution in water from a central source through a circulatory system which comprises the source, a pump, the or each pan and the necessary piping. In the case of a plurality of pans the latter may be connected in the system in series or parallel. In the described embodiment the source comprises a tank 20, Fig. 3, having two compartments 24, 26, Fig. 1, the former containing the " etch and gum " concentrate whilst the latter holds the solution already mixed to the desired proportions. A pipe 42 connects the compartment 26 with the pan or pans, the return flow of the circulating solution being effected through a pipe 44 which leads back into the compartment via a filter bed 54. The solution is maintained in the compartment 26 between predetermined upper and lower limits by an electrical control element 100. When replenishment of the solution is necessary through actuation, by the element 100 at the lower limit, of the pump motor 41 and fluid-control valves 104, 106, 108 and 109, " etch and gum " concentrate is drawn from a measuring tank 34, disposed beneath the tank 20, into the compartment 26 by an aspirator 38 actuated by the water supply thereto as it passes through piping 30. Whilst fresh solution is being made the circulatory system is at a standstill. The amount of concentrate withdrawn is controlled by the setting of a knob 64, Fig. 5, on the tank which determines the position relative to the top of the tank of the inlet 71 of a tube 72 which is fixedly mounted on a shaft 60 rotatable by the knob 64 and is also in direct connection with the discharge pipe 36 of the tank 34. When the upper limit is reached in the compartment 26 the element 100 reacts to re-start the pump 40 and, after a suitable time-lag, re-opening the valves 104 and 109 whilst closing the valves 106 and 108. Thereupon the circulatory system is reestablished whilst fresh concentrate passes from the compartment 24 to the tank 34 in readiness for the next solution replenishment stage when the element 100 again reacts at the lower limit. The system also incorporates piping and solenoid valves which enables the tanks, pipes and pans to be periodically flushed with hot water. The electrical control circuit described with reference to Fig. 6 (not shown) incorporates the necessary switches, relays &c. for the automatic functioning of the circulatory and replenishment stages and, through the normal actuation of changeover switches, the functioning of the flushing arrangements.