US2821132A - Method and apparatus for controlling water supply in planographic printing press - Google Patents

Description

Jan. 28, 1958 G. R. BRODIE 2, METHOD AND APPARATUS FOR CONTROLLING WATER SUPPLY IN PLANOGRAPHIC PRINTING PRESS Filed Dec. 13, 1954 INVENTOR. George R. Brodie METHOD AND APPARATUS FOR CONTROLLING WATER SUPPLY 1N PLANOGRAPHIC PRET- ING PRESS George Rogers Brodie, Lower Merion Township, Montgomery (lounty, Fa assignor to Fredk H. Levey Company, inc, New York, N. Y., a corporation of New York Application December 13, 1954, Serial No. 474,772

4 Claims. (63!. 101-438) This invention relates to the art of printing and, particularly, to improvements in the construction and operation of web-fed multi-color printing presses adapted to print from planographic printing plates. More particularly, the invention relates to the control of the rate at which water is applied to the respective plates.

The surfaces of planographic printing plates are generally bimetallic, one metal having the characteristics of being wet with Water and the other having the characteristics of being wet with ink, as is well understood in the art. In printing from such plates, water is first applied to the plate surface and thereafter ink is applied, as by means of separate rollers, the surfaces of the rollers being wet with water and ink respectively and rotating in contact with the plate surface.

The rate at which water must be applied to the plate surfaces for optimum printing quality is rather critical and must be carefully regulated and controlled. It all depends, in part, upon the area of the non-printing surface of the plate. The required amount of water to be supplied to a plate during normal printing time is substantially less than that required during the starting-up period of the press and, therefore, adjustments for optimum starting-up conditions must be carefully made each time the press is put in operation and, when the plates have been properly wetted, the adjustments must be carefully changed so as to supply water thereto at a rate just sufiicient to maintain optimum printing conditions.

In multi-color printing, a plurality of such planographic plates is used, one for each color and, since the area of printing surface is usually very different for one color than for another color, the rate at which water is applied to each plate must be carefully adjusted to attain optimum printing conditions when starting up the press and separate readjustments must be made for each cylinder to maintain those conditions during normal operation of the press.

In modern press design it has been customary to apply the water to each plate cylinder by means of rollers operating in contact with the plate surface thereon, and to supply the water to the respective rollers by means of separate fountain rollers, the rate at which water is supplied to each plate surface being controlled by adjusting the speed of rotation of the fountain roller associated therewith.

In multi-color printing on web-fed presses it is not unusual to use as many as five difierent colors, thus requiring five separate plate cylinders to which water must be supplied at different rates, both during normal operation and during the starting-up of the press. Thus separate adjustments must be made in starting the press and bringing it to normal operation. These adjustments have been time-consuming and expensive, particularly where frequent stopping and starting of the press has been necessary.

My present invention provides improved method and means for controlling and regulating the rate at which the water is supplied to printing presses of the multi-color aired tates ten ice web-fed type, just described, whereby separate adjustments of the speed of rotation of each fountain roller can be made for optimum printing conditions during the starting-up period and a separate adjustment can be made for each of the fountain rollers for normal operation, without disturbing the first set of adjustments, and the speed of rotation of the respective fountain rollers can be switched simultaneously and automatically from starting-up operation requirements to normal operation requirements or vice versa.

My invention will be further described and illustrated with reference to the accompanying drawing which represents diagrammatically and conventionally an embodiment of my invention in a web-fed multi-color rotary type press. For simplicity, only three plate cylinders have been shown, but it will be understood that the invention is applicable to printing presses containing any number of plate cylinders in excess of one.

In the drawing, the impression roller is indicated at 1 and the plate cylinders are indicated at 2. Planographic printing plates are secured to the surfaces of the cylinders 2 by means well known to the art, and are wetted with water by passing in rolling contact with the surfaces of rollers 3 to which water is supplied by rollers 4 operating in contact with the fountain rollers 5, the lower surfaces of which are submerged in water maintained at a constant level in the fountains 6.

After water has been applied to the plates, as just described, ink is applied thereto by means of form rollers 7 and thereafter the surfaces of the plates 2, which have been Wet with water and then with ink, pass in contact with blanket cylinders 8 which pick-up and apply the ink to the web 9 passing about the impression cylinder 1. In passing to and from the impression cylinder, the web passes over idler rollers 10.

Each fountain roller is driven by a separate motor indicated at 11. For simplicity, I have in the drawing indicated a direct coupling of the drive shaft 14 of the motor with the shaft of the fountain roller. However, any suitable means for driving the fountain roller by the motor may be used, including reduction gears.

The motors 11 are, with advantage, of the hydraulic type and each is connected with a fluid pump 15 by means of conduits 16 and 17 through supply lines 18 leading to the motor and discharge lines 19 leading from the pump. Efiiuent liquid from the motors is passed through lines 20 to reservoir 21 with which the pump is connected through line 22.

Positioned in each of the lines 16 and 17 adjacent each of the motors are flow control valves 23 and 24, respectively. I have also, with advantage, placed check valves 25 and 26 in these respective lines between the flow control valves and the motor.

Positioned in line 17 adjacent the pump is a shut-01f valve 27 and similarly positioned in line 16 is a shut-off valve 28. Also positioned in line 19 adjacent the pump is a relief valve 29.

With the press in normal operation, I may, for example, close valve 28 and open valve 27, thereby causing the motivating fluid to flow from the pump to the respective motors through lines 17. I then adjust each of the valves 24 so as to regulate the speed of the motor asso ciated therewith to drive the fountain roller 5 at a speed such as to deliver the optimum amount of water to the plate cylinders through rollers 3 and 4 under normal operating conditions. I may then close valve 27 and open valve 28 and similarly adjust the respective valves 23 so as to operate the motor at a speed at which the optimum amount of water is delivered to the plate cylinder associated therewith under starting-up conditions.

Having thus adjusted each of the valves 23 and 24 for a particular press set-up, the adjustments need not be I 3 disturbed so long as that particular press set-up is being used, regardless of press shut-clowns for purposes other than changing the press set-up.

In starting up the press, the valve 27 will be closed and the valve 28 opened, so as to operate the respective motors at the predetermined speed to supply the required larger amount of water to the respective plate cylinders. When normal operating conditions have been attained, the valve 28 is closed and the valve 27 opened, thus simultaneously and automatically switching from the adjustment of valve 23 to that of valve 24 without in any Way disturbing any of those adjustments.

While I have shown separate control valves 27 and 28, it will be understood that in place thereof 1 may use a single three-way valve for switching the flow of motivating fluid from conduit 16 to conduit 17, or vice versa, as required.

The valves 27 and 28 may be either manually or automatically operated. In either event, no tedious, timeconsuming adjustments need be made and the entire press canreadily be switched from one condition to the other substantially instantaneously.

Since the peripheral speed of the rollers 3 and 4 is dependent upon the peripheral speed of the plate cylinders 2, it is usually necessary that the fountain rollers 5 be so constructed and arranged that their peripheral speed is independent of the speed of rotation of rollers 4. This is, with advantage, accomplished by the use of fountain rollers of the brush or loop type. It will be understood that the invention is not restricted to the particular arrangement of the water train shown in the drawing, but that other types of Water-supplying means may be used whereby the rate at which the water is supplied is de pendent on the speed of operation thereof.

I claim:

1. In conjunction with a multi-color, web-fed printing press comprising a plurality of plate cylinders, adapted to hold planographic printing plates in position during printing, and means for separately applying Water to the plates on the respective plate cylinders by which the rate at which water is applied to the respective plates may be varied by varying the speed of operation of the Watersupplying means associated therewith, a plurality of fluid motors each mechanically connected to drive one of the water-supplying means, a fluid pump, a conduit leading from the pump, a shut-off valve positioned in said conduit, connections leading from the conduit beyond said valve to each of the motors, a flow control valve positioned in each of said connections, a second conduit leacing from the pump, a shut-off valve positioned in said conduit, connections leading from the second conduit at a point beyond the valve to each of the motors, and a flow control valve positioned in each of the last said connections.

2. A printing press adapted to use in multi-color printing from planographic printing plates and comprising a plurality of plate cylinders each adapted to hold a plate in position during printing, means for separately applying water to the plates on the respective plate cylinders including a fountain roller, whereby the rate at which the water is applied to the plates on the respective cylinders is varied by varying the speed of rotation of the associated fountain roller, a plurality of fluid motors, each mechanically connected to drive one of the fountain rollers, a fluid pump, a conduit leading from the pump, a shut-01f valve positioned in said conduit, connections leading from the conduit beyond said valve to each of the motors, a flow control valve positioned in each of said connections, a second conduit leading from the pump, a shut-off valve positioned in said conduit, connections leading from the second conduit at a point beyond the valve to each of the motors, and a flow control valve positioned in each of the last said connections.

3. In the process of multi-color printing from a plurality of planographic printing plates to which water is applied prior to the application of ink thereto at rates dependent on the speed of operation of the water-supplying means, the method of regulating the rate at which water is applied to the respective plates during the starting-up period and during normal operation of the press, which comprises providing alternate paths by which motivating energy is supplied to the water-supplying means, separately adjusting the rate at which water is to be supplied to the respective plates during the starting period of the press by adjusting the amount of energy supplied to the respective water-supplying means over one of said paths, separately adjusting the rate at which water is to be supplied to the respective plates during normal operation of the press, without disturbing the first adjustments, by adjusting the amount of motivating energy supplied to the respective water-supplying means over the second of said paths, passing the motivating energy to the respective water-supplying means over the first said path when starting the press and switching the motivating energy to the second said path when normal operating conditions have been attained.

4. In the operation of a multi-color rotary printing press in which water is supplied by a plurality of fountain rollers to separate planographic plates and the rate at which the water is supplied to the respective plates is regulated by regulating the speed of rotation of the associate fountain roller, each fountain roller being driven by a separate fluid motor, the steps comprising providing two alternate paths by which the motivating fluid may be supplied to each of the motors, adjusting the rate at which the fluid is to be supplied to each of said 1110- tors over one of the paths to apply the required amount of Water to each of said plates during the starting-up of the press, separately adjusting the rate at which the fluid is to be supplied to each of the motors over the second of said paths to apply the required amount of water to the respective plates during normal operation of the press, without disturbing the first said adjustments, passing the fluid to the respective motors over the first said path while starting the press and switching the fluid to the second of said paths when normal operating conditions have been established.

References Cited in the file of this patent UNITED STATES PATENTS 2,230,503 Roesen Feb. 4, 1941 2,233,210 Huck Feb. 25, 1941 2,690,120 Burroughs Sept. 28, 1954

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