US3462300A - Method and apparatus for supplying liquid under constant high pressure and abruptly cutting off the supply - Google Patents

Description

INVENTOR [/rey 190cm? U. HOCUTT OFF THE SUPPLY Filed Nov. 18, 1966 CONSTANT HIGH PRESSURE AND ABRUPTLY CUTTING METHOD AND APPARATUS FOR SUFPLYING LIQUID UNDER Aug. 19, 1969 US. Cl. 13433 6 Claims ABSTRACT OF THE DISCLOSURE Jet streams of liquid under high pressure are directed against a rotatably mounted brush to wash it and to rotate it at high speed, and the supply of liquid is cut oif abruptly leaving the brush rotating at high speed to dry. The jet streams are supplied by forcing a predetermined volume of liquid from a single orifice container at-a constant rate until the liquid is completely exhausted, using a first piston head which is tied to a second piston head which may be reciprocated in a smaller container by liquid introduced alternately on opposite sides, the tie rod between the two piston heads carrying means adjustable in position for triggering a normally closed valve thereby determining the length of stroke of the piston and the amount of liquid exhausted from the single orifice container by the first piston head.

This invention relates to method and apparatus for first supplying liquid under substantially constant high pressure and then cutting it off abruptly without the use of a valve. In the particular application of the invention described herein cleaning liquid is supplied under high pressure, on the order of 450 p.s.i., and directed in the form of fluid jets against the surface of a rotatably mounted color transfer brush of the kind employed in the cloth printing art, to clean it. In this art it is essential to reduce the non-productive, down time as much as possible, and the step of directing jets of cleaning liquid under high pressure against a brush in such a way as to cause the brush to rotate at very high speed has been found to result in cleaning of the brush in a remarkably short time. The jet streams are fan shaped with each fan similarly inclined to the axis of the brush. The streams strike against adjacent circular areas of the brush surface and collectively cover the entire surface of the brush as the brush rotates. At any moment while the jets are operating part of each jet stream is directed radially against the brush cylinder, the groups of bristles projecting from it, and the spaces between the groups of bristles, and part is directed angularly against the bristles and tangentially of the cylinder and causes the brush to rotate. When the brush is thus rotated at high speed the centrifugal force is such that the color and cleaning liquid are thrown off at once.

In order to reduce the non-productive, down time, which has always plagued this art, it is just as important to dry clean brushes as quickly as possible as it is to clean them as quickly as possible so that they will be in condition to resume a cloth printing operation. I have found that a brush rotated by jets of cleaning liquid under pressure of approximately 450 p.s.i. will attain a very high speed of rotation, and that if the cleaning liquid can be shut off without substantially reducing the speed of rotation of the brush attained during the cleaning phase the brush will dry itself almost instantaneously.

A great practical difliculty is the fact that to turn off the flow of liquid under such high pressure by means of a valve will produce a terrific water hammer and is likely to destroy the valve, whereas turning the valve ofif slowly will gradually lessen the force of the jets impinging on the brush and so very materially lessen the speed of rotation of the brush before the start of the drying phase, thereby greatly increasing the non-productive, down time consumed for drying the brush.

It is an object of the invention to provide a method and apparatus for abruptly terminating the supply of high pressure liquid by means other than a shut off valve.

Another object of the invention is to supply a predetermined volume of liquid under a constant high pressure, within a predetermined period of time, and to cut off the supply abruptly, without using a shut off valve and without a gradual reduction in pressure of the liquid near the end of the period within which it is being supplied.

Another object of the invention is to provide a satisfactory method and apparatus for ending a brush cleaning operation during which the brush has been rotated at high speed, without substantially reducing the speed of rotation which the brush has attained during the cleaning phase.

The invention will be best understood by reading the following description in connection with the drawings in which The figure is a diagrammatic view of apparatus for carrying out the invention.

In carrying out my invention I propel a first piston head within a first cylinder, using a first liquid, hereinafter referred to broadly as oil, under pressure, as the propellant, and use the motive force of the first piston head to propel a second piston head in a second cylinder containing a second liquid. I provide means for supplying oil alternately on opposite sides of the piston head in the first cylinder to reciprocate the first piston head and thus also to reciprocate the second piston head, and employ the back stroke of the piston head in the second cylinder to suck the second liquid into the second cylinder from a reservoir, and employ the forward stroke of the piston head in the second cylinder to expel liquid from the second cylinder. In the embodiment of the invention shown and described herein the liquid supplied to the second cylinder is a cleaning liquid and the cleaning liquid is expelled from the second cylinder into a header provided with a number of nozzles which direct jets of cleaning fluid against a rotatably mounted brush. By controlling the pressure in the second cylinder and the number and size of the nozzle orifices (i.e. the total discharge port area of the header) I can discharge a desired volume of cleaning fluid against the brush, within a predetermined period of time and under pressure sufficient to rotate the brush at high speed, thus employing centrifugal force to throw off color and cleaning fluid from the brush cylinder surface and bristles and thus cleaning the brush, and, by the means disclosed herein the supply of cleaning liquid can be abruptly cut off without first slowing the speed of rotation of the brush by tapering off the pressure of the jet streams of cleaning liquid. The high speed of rotation imparted to the brush during the cleaning period is thus substantially maintained long enough for drying the brush.

By employing first and second cylinders equal in length, with the first cylinder having a smaller diameter than the diameter of the second cylinder, a relatively small oil pump may be employed even though a large volume of cleaning fluid is discharged from the second cylinder in a very short time period. The p.s.i. applied to the first cylinder is in inverse ratio to the square area of the first piston 22 and the second piston 42 in order to realize the desired p.s.i. in the second cylinder.

Since the second cylinder is provided with only one port the length of stroke of the piston head in the second cylinder may be varied for even if at the end of the discharge stroke liquid is left in the second cylinder, between the piston head and the discharge port, atmospheric pressure will prevent the escape of liquid from the second cylinder after the movement of the piston head, within the second cylinder, is stopped.

The numeral identifies the first cylinder and the numeral 12 identifies the second cylinder. A pump 14, which may be actuated by the motor 16, is shown connected between an oil storage tank 18 and the cylinder 10. Between the pump 14 and the cylinder 10 an oil accumulator chamber 20 is provided which is large enough to insure at all times a supply of pressure fluid sufficient to move'the piston head 22, within cylinder 10, the full length of cylinder 10. The portion of the conduit between oil storage tank 18 and the pump 14 is identified by the numeral 24; the portion between the pump and the oil accumulator by the numeral 26; and the portion between the oil accumulator 20 and the cylinder 10 by the numeral 28. The conduit 28 comprises the branches 28a an 28b which communicate respectively with the near and far ends of cylinder 10, on opposite sides of the piston head therein. Branch 28a is controlled by solenoid valve 30 and branch 28b is controlled by solenoid valve 32.

Conduits 34 and 36 lead from opposite ends of cylinder 10 to oil storage tank 18, and serve, as the piston head 22 is reciprocated within cylinder 10, to return oil to oil storage tank 18 from the end of cylinder 10 toward which the piston head is moving. Conduit 34 is controlled by valve 38 and conduit 36 is controlled by valve 40.

In cylinder 12 the piston head 42 is provided, and piston heads 22 and 42 are interconnected by piston rods 23 and 43 which extend toward one another and are interconnected between the opposed ends of the spaced cylinders by the coupling 44. Although cylinder 12 is illustrated as being of much greater diameter than cylinder 10 it is shown as having the same length as cylinder 10, and the two cylinders are shown spaced apart by a distance equal to the length of either cylinder 10 or 12 plus the length of the coupling 44. This allows the length of the stroke of the piston heads 22 and 42 to be controlled throughout a range of strokes from zero to a distance equal to the length of either cylinder 10 or 12, by control means including an abutment member 46 shown projecting downwardly from the coupling 44, in position to abut against the head 48 of the normally closed switch member 50, and opens it. Switch member 50 may be moved toward and away from member 46 to adjust the length of the stroke of pistons 22 and 42.

It will be noted that cylinder 12 has only one port, 52, for supplying liquid into cylinder 12, when the piston head is moving away from port 52, and for the discharge of liquid from cylinder 12 when the piston head 42 is moving toward the port 52.

Port 52 is shown connected with a header 56 within a washer receptacle 58 by means of a conduit 60 having therein the normally closed valve 62. The portion 60a of conduit 60 is shown as a flexible conduit. A conduit 64, having therein the oneway valve 66, leads from the cleaning liquid tank 54 to conduit 60 between port 52 and the solenoid valve 62 in conduit 60.

The header 56 has a number of nozzle 68 and is mounted within washer-receptacle 58 which is provided with a drain 70. The nozzles 68 are directed toward a brush 72 which is shown with its spindles 74, 74 extending through the respective ends of an inverted color box 76, and supported for rotation within the bearings 78, 78.

This invention is not concerned with how the color box 76 is inverted and superimposed upon a washerreceptacle 58.

In US. Patent 3,227,078, Jan. 4, 1966, the method is taught and apparatus is disclosed for moving a color box away from its print roll and inverting and superimposing it upon a washer-receptacle to form a closure with the inner surface of the color box, and the brush, disposed entirely within the closure, and for directing jets of cleaning fluid against the surface of the brush and the inner surface of the color box to clean them within the closure.

So far as this invention is concerned the color box 76 and the washer-receptacle 58 may be brought together manually to form a closure, and thereafter separated manually. This invention is concerned with a method and means of supplying the liquid under pressure and abruptly cutting off the supply of the liquid, and the employment of the method and means to clean and dry the brush 72 is shown as an illustration of a practical and useful application of the method and means.

I have found that by delivering twelve gallons of cleaning liquid from cylinder 12 within five seconds and directing it in jet sprays, as from nozzles 68, against a brush mounted for rotation which is fifty-four inches long and six inches in diameter and thoroughly wetted with any of the colors used in color printing, the brush will attain such a high speed of rotation that it will clean itself within approximately five seconds, and will become dry within approximately two seconds after the supply of cleaning liquid has been cut off, provided the force of the jet sprays, and therefore the speed of rotation of the brush, has not been decreased prior to complete shut off by gradual lessening of the pressure of the liquid in the header 56.

An electrical control circuit is shown, by which the supply of oil to the cylinder 10, in a direction to move piston head 22 in cylinder 10 to move piston head 42 in cylinder 12 for discharging liquid therefrom into discharge conduit 60 and header 56, is begun as soon as the color box 76 is superimposed upon the washer-receptacle 58. As illustrated, the abutment member 80 carried at one end of the inverted color box 76 strikes against the normally opened movable switch member 82 thus closing a circuit from a suitable power supply 84 to the coils of normally closed solenoid valves 30 and 40, thereby opening valves 30 and 40 and closing valves 32 and 38, and opening valve 62 and allowing the previously actuated pump 14 to supply oil under pressure from storage tank 18 into cylinder 10 through conduit 28a thus initiating a discharge stroke of the piston heads 22 and 42.

When the piston heads have reached the end of the desired stroke, and the desired volume of liquid has been discharged from cylinder 12, the abutment member 46 on coupling 44 will strike and open the normally closed switch means 50, the position of which between cylinders 10 and 12 may be adjusted as desired, thus allowing valves 32 and 38, to go back to normally open position, and valve 62 to go back to normally closed position, and at the same time closing valves 30 and 40, thereby diverting oil from tank 18 to the far end of cylinder 10 through conduit 28!), and thus causing pistons 22 and 42 to move in a direction away from the discharge port 52 of cylinder 12. When abutment member 46 strikes and opens normally closed switch 50, the switch arm 82 is returned to open position, before abutment member 46 leaves switch member 50 and while the latter is being held open by member 46, in any suitable way. As the return movement of piston head 42 starts valve 62 will be closed and suction in cylinder 12, caused by the return stroke of piston 42, will allow cleaning liquid from tank 54 to refill cylinder 12.

There has thus been provided a method and apparatus in which the above mentioned objects are accomplished in a thoroughly practical manner.

What I claim is:

1. The method of washing and thereafter quickly drying a rotatably mounted brush which comprises, directing a number of high pressure jet streams of washing liquid against the periphery of the brush at constant high pressure to simultaneously rotate the brush at high speed and to wash it, and cutting off the supply of washing liquid forming said jet stream abruptly and without first substantially reducing the pressure under which the liquid is being supplied, thereby leaving the brush rotating at high speed to dry.

2. The method claimed in claim 1 including the steps of providing the washing liquid to form the jet streams from a container having a single orifice, supplying liquid into the container through said orifice and thereafter exerting a constant high pressure on the liquid in the container while expelling a predetermined amount of liquid from the container to form the jet streams.

3. The method claimed in claim 2 including the steps of, moving a piston head in one direction within its container to provide space between the piston head and the discharge end of the container for liquid supplied into the container, moving the piston head in the opposite direction within the container a predetermined distance and at constant speed to force a desired volume of the liquid out of the container, and thereafter abruptly cut off the flow of liquid from the container and controlling the speed of movement of the piston to control the pressure of the liquid discharged from the container to form the jet streams.

4. In combination a brush, means for mounting the brush for rotation, a header having a number of jet orifices pointed at the brush for directing jets of washing liquid against the brush at high speed and to wash it, a supply of washing liquid, means for supplying the washing liquid to said header at high pressure, and means for cutting otf the supply of washing liquid to the header abruptly without fluid hammer, and without first substantially reducing the pressure under which the liquid is being supplied.

5. Apparatus for supplying a volume of liquid under high pressure to jet outlets and directing streams of liquid from said jets against the surface of a rotatable brush to simultaneously wash the brush and rotate it at high speed and for cutting off the supply of liquid abruptly thus leaving the brush rotating at high speed to dry, which comprises, a header having a number of jet orifices, means for rotatably mounting a brush in position to be contacted and rotated by high pressure jet streams issuing from said orifices, first and second liquid containers, piston heads in each of the containers, means for supplying liquid into, and discharging it from, the second of said containers from the same side of the piston therein, means,

including valve means, for alternately introducing liquid under pressure into, and exhausting it from, the first container on opposite sides of the piston head therein to reciprocate the piston head within the first container, and means interconnecting the piston heads for movement in unison.

6. The apparatus claimed in claim 5 in which the two liquid containers are spaced apart and the piston heads in thetwo liquid containers are interconnected by piston rod means, which extend into the space between the containers, and means for coupling the piston rod means between the two containers, the two containers being of the same length, and being spaced apart a distance equal to the length of either of said containers plus the length of the said coupling, abutment means movable axially with saidpiston rod means and an electric circuit for controlling said valve means including switch means adjustable in position axially of the piston rod means, and responsive to contact with the abutment means to vary the stroke of said piston heads.

References Cited UNITED STATES PATENTS 3,227,078 1/1966 Johnson 101 425 XR 1,888,953 11/1932 Humphrey.

1,984,296 12/1934 Witter 222-334 XR 2,080,695 5/1937 C-argile 103 2,553,788 5/1951 Richardsonetal.-- 222334XR 2,888,029 5/1959 Govan et al. 137-565 XR 2,892,438 6/1959 Hery.

3,174,649 3/1965 Richardson 103 50 XR 3,279,383 10/1966 Smith 1035OXR 3,348,520 10/1967 Lockwood 118 2 OTHER REFERENCES 907,057 10/1962 Great Britain.

686,778 1/1963 Canada.

DANIEL BLUM, Primary Examiner US. Cl. X.R.

lOl--425, 426; 10350; l34l39; 137-14

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