US3429508A

US3429508A - Fluid selection system

Info

Publication number: US3429508A
Application number: US575026A
Authority: US
Inventors: Michael R Russinik
Original assignee: GRAY CO Inc
Current assignee: GRAY CO Inc
Priority date: 1966-08-25
Filing date: 1966-08-25
Publication date: 1969-02-25
Anticipated expiration: 1986-02-25
Also published as: DE1625216B2; DE1625216A1

Description

Feb. 25, 19 69 M. R. RUSSINIK 3,429,508

' FLUID SELECTION SYSTEM Filed Aug. 25, 1966 1N VEN TOR. M/d/MEL EEUSS'M/l( I BY United States Patent 3,429,508 FLUID SELECTIGN SYSTEM Michael R. Rnssinik, Minneapolis, Minn., assignor to Gray Company, Inc., Minneapolis, Minn., a corporation of Minnesota Filed Aug. 25, 1966, Ser. No. 575,026

US. Cl. 239-126 Claims Int. Cl. B05b 7/04, 7/26 ABSTRACT OF THE DISCLOSURE A fluid selection system for selectively spraying at least two fluids, such as water and a soap or detergent and water solution. The system includes a constant flow rate fluid pump, and the outlet of the pump is connected with a spray gun having two different sized spray orifices so that the outlet pressure of the pump depends on which of the two orifices is being used for spraying. The inlet of the pump is connected with containers for the fluids to be sprayed, and a valve is positioned in a conduit interconnecting one of the containers and the inlet of the pump for controlling the flow through the conduit. The valve is actuated by a spring biased piston, one face of which is directly exposed to the outlet pressure of the pump so that the piston moves, and thus the valve is opened or closed, in response to the variation in the outlet pressure of the pump caused by selectively using one or the other of the orifices on the spray gun for spraying.

The invention relates to a novel and improved fluid selection system, and more specifically, to a novel and improved fluid selection system particularly adapted to be used in industrial spray cleaning equipment wherein a relatively high pressure spray of water or alternatively, detergent solution, is used for cleaning.

In the past, equipment for a variety of purposes has required fluid systems wherein a plurality of fluids could be selectively sprayed through a common nozzle. To achieve this result, many different types of fluid selection systems have been developed.

An example of equipment requiring such a fluid selection system is industrial spray cleaning equipment which utilizes a high pressure spray of either water or detergent solution to clean accumulated dirt, grime and grease from machinery, motor vehicles and the like. Commercially available cleaning equipment includes a pump, a plurality of fluid reservoirs and a spray gun, which may be connected to the pump outlet by means of hose or other flexible conduit. A number of electrically actuated valves and switches are utilized to control which of a plurality of fluids is to be sprayed from the spray gun. For convenience, the switches are mounted on the spray gun so that the user of the gun does not have to stop spraying and return to the pump when it is desired to change the fluid being sprayed. While this fluid selection system performs satisfactorily, the cost of the valves and switches used in the system significantly increases the over-all cost of the equipment.

It has also been suggested that a satisfactory fluid selection system for spray cleaning equipment could be obtained by using a pressure relief valve, positioned in the conduit interconnecting the pump and spray gun, to actuate an electrical switch that, in turn, controls an electrically actuated valve in the conduit connecting the inlet of the pump to a source of water. In this system, the relief valve is actuated, and thus the particular fluid being sprayed is changed every time that the trigger of the spray gun is released, e.g., every time the manually actuated valve in the spray gun is opened and closed by the user of the gun. While this system does require fewer electrically actuated valves and switches and thereby does somewhat reduce the over-all cost of the cleaning equipment, the system does not permit a real selection of the fluids to be sprayed since every time the gun is used, a different fluid is sprayed. In other words, it is impossible to continuously spray only one fluid from the gun if the trigger of the gun is not continuously depressed. Thus, this system is obviously inconvenient, and in some cases, impractical to use.

Briefly and in contrast, this invention provides a greatly simplified, highly reliable and relatively inexpensive system for selectively spraying a plurality of fluids. As noted above, this novel and improved fluid selection system has particular utility in industrial spray cleaning equipment. In this system, selection of the fluid to be sprayed is achieved by controlling the pump outlet pressure or in other words, the pressure of fluid in the conduit connecting the pump to the spray gun. Valve means, positioned in the conduit connecting one of the fluid reservoirs to the pump and directly responsive to the pump outlet pressure, permits the flow of fluid through the conduit when the pump outlet pressure exceeds a predetermined value and prevents flow of fluid through the conduit when the pump outlet is less than the predetermined value. In the preferred embodiment of this invention, the pump outlet pressure is controlled by selectively using different sized spray orifices in the gun for spraying. In other words, a certain size spray orifice is used when one fluid is to be sprayed, while a different size orifice is used when another fluid is to be sprayed.

A primary object of this invention is to provide a novel and improved fluid selection system for selectively spraying a plurality of fluids from a nozzle or spray gun, which system has particular utility in industrial spray cleaning equipment.

Another object of the present invention is to provide a novel and improved fluid system for spraying a plurality of fluids in which the pump outlet pressure is utilized to control the selection of the fluid to be sprayed.

Another object of the present invention is to provide a novel and improved fluid selection system in which valve means is positioned within a conduit connecting one of the fluid reservoirs with the inlet of the pump and is responsive to the pump outlet pressure whereby flow through the valve means is permitted when the pump outlet pressure exceeds a predetermined value and flow is prevented through the valve means whenever the pump outlet pressure is less than the predetermined value.

Still another object of the present invention is to provide a novel and improved fluid selection system wherein the pump outlet pressure is controlled by using ditferent sized spray orifices, i.e., the spray orifices having different effective diameters. A related object of the present invention is to provide a spray tip assembly mounted on the spray gun, the assembly having two different sized spray orifices and permitting the user of the system to change quickly and easily from one orifice to the other and thereby control which of two fluids is to be sprayed from the spray gun.

Another object of the present invention is to provide a novel and improved fluid selection system particularly useful in industrial spray cleaning equipment, which system primarily utilizes standard, commercially available components and does not require the use of relatively expensive electrically actuated valves and switches.

These and other objects and advantages of the invention will become apparent from the following description of the preferred embodiment of the invention described in conjunction with the following drawing in which:

FIGURE 1 is a schematic view of the novel and improved fluid selection system of this invention as used for industrial spray cleaning, and including an enlarged vertical cross-sectional view of the pressure responsive valve means;

FIGURE 2 is a partial vertical cross-sectional view of the spray tip assembly; and

FIGURE 3 is a perspective view of the spray tip member showing the two different size spray orifices formed therein.

Referring now to FIGURE 1, the improved fluid selection system .11 of this invention includes a tank or reservoir 12 which provides a source of the base or the principal fluid to be sprayed. A second tank or reservoir 13 provides a source of the additive or the secondary fluid which may be mixed with the base fluid, in desired proportions, and sprayed as more fully explained hereinbelow. When this improved system is used for industrial cleaning equipment, it will be understood that the base fluid is water and the additive fluid is a soap or detergent solution.

This tank 12 communicates with the inlet 14 of a pump 15 through conduit 16. Note that the end of the conduit 16 which extends within the tank 12 has a conventional strainer 17 connected thereto whereby any solid particles in the base fluid are prevented from entering the fluid system. The additive fluid in the tank 13 communicates with the inlet 14 of the pump 15 through a conduit 18, 'valve means 19, conduit 21, adjustable restrictor 22 and the conduit 16. Of course, if desired, the conduit 21 may be connected directly to pump inlet 14.

The pump 15 may be either a conventional rotary or reciprocating pump which is continuously driven by a motor means, not shown, and which creates a suction at its inlet 14 during operation. The flow rate of the pump must remain constant regardless of the outlet pressure of the pump.

The outlet 23 of the pump is in fluid communication with a conventional spray gun 24 through a conduit 25. The spray gun 24 has a manually operated trigger 26 which permits the user of the spray gun to control the flow of fluid through the gun. A spray gun which may be used is the Model 205-939 spray :gun manufactured and sold by the Gray Company, Inc. of Minneapolis, Minn. Conduit 27 permits recirculation of the fluid from the gun back to the inlet 14 of the pump 15 when the spray gun is not being used.

The valve means 19 comprises a generally cylindrical body 28 which has an internal chamber 29 formed therein. The chamber 29 is divided into first and

second portions

31 and 32, respectively, by an annular, radially inwardly projecting flange 33. A centrally disposed aperture 34 is formed in the flange 33 and permits fluid communication between the

portions

31 and 32 of the chamber 29. The first portion 31 also communicates with the terminal end 35 of the conduit .18 whereby additive fluid from the tank 13 may flow unrestrictively into the first portion 31 of the chamber 29. A conventional fastening and sealing means 36 connects the end 35 of the tubing 18 in an aperture 37 formed in the end 38 of the body 28-.

A conventional fastening and sealing means 3-9 connects the tubing 21 in an aperture 40 formed in the side 41 of the body 28 so that the second portion of the chamber 29 is always in fluid communication with the conduit 21. A branch conduit 42 interconnects portion 32 of the chamber 29 with the conduit which, as noted above, connects the pump outlet 23 to the spray gun 24. A conventional fastening and sealing means 43 connects the end of the conduit 42 to an aperture 43 formed in the end 44 of the body 28.

A piston 45 is positioned within the second portion 32 of the chamber 29. The outer periphery of the piston is congruent to the interior of the portion 32 and the piston is of such a size that it freely slides within the portion 32 of the chamber. However, to insure that no fluid leakage occurs across the piston, a sealing ring 46 is positioned in a groove 47 formed about the periphery of the piston.

As shown in FIGURE 1, one face 48 of the piston 45 is exposed to the fluid in branch conduit 42 a d the Pressure exerted by this fluid, of course, urges the piston 45 to move to the left from the position shown in FIGURE 1. The other face 49 of the piston has a centrally disposed shaft 50 projecting therefrom which extends through the aperture 34 in the flange 33 The shaft 50 carries a valve assembly 51 at the end 52, remote from the piston 45. This valve assembly is secured to the end of the shaft by a retaining screw and washer 53, and consists of a truncated conically shaped, annular valve member 54 which may be formed of resilient, wear-resistant material. The length of the shaft is selected so that when the piston is in the position shown in FIGURE 1, the valve member 54 contacts the edge 55 of the flange 33 which serves as a valve seat. Thus, when the valve member 54 is in this position, fluid communication between the portion 31 and the portion 32 of the chamber 29 is prevented whereby the flow of additive fluid from the tank 13 to the pump inlet 14 is interrupted.

A coil compression spring 56 is positioned between the flange 33 and the face 49 of the piston 45. This spring 56 biases the piston toward the position shown in FIG- URE 1. As noted above, the face 48 of the piston is exposed to the fluid in the branch conduit 42. However, the force exerted by the coil spring 56 on piston 45 is such that until the pressure of a fluid in the conduit 42 exceeds a certain predetermined value, the piston remains in the position shown in FIGURE 1. Moreover, as explained above, when the piston 45 is in that position, the valve member 54 contacts the valve seat 55 thereby preventing fluid communication between the

portions

31 and 32 of the chamber 29. However, when the fluid pressure in the conduit 42 exceeds the predetermined value, the fluid force acting on the face 48 of the piston 45 overcomes the bias of the spring 56 and the piston moves to a second position, to the right of that shown in FIGURE 1. This movement of the piston causes a concomitant movement of the valve 54 away from seat 55 thereby permitting fluid communication between the tank 13 and the inlet 14 of the pump 15. In this second position, the face 49 of the piston 45 is adjacent the edge of the aperture 40 but never blocks flow through the aperture 40.

The adjustable restrictor 22 positioned in conduit 21 between valve means 19 and conduit 16 may be a conventional adjustable needle valve, As mentioned above, the function of this restrictor is to control the volume or proportion of additive fluid flowing to the pump inlet 14, relative to the volume of base fluid.

The pressure of the fluid flowing in conduit 25 and thus in conduit 42 is controlled by varying the size or the effective diameter of the spray orifice of the spray gun 24. By decreasing the size or the effective diameter of the spray orifice of the gun 24, the pressure in

conduits

25 and 42 is increased and conversely, when the eflective size or diameter of the spray orifice of the gun 24 is increased, the pressure in

conduits

25 and 42 is decreased.

This change in the diameter of the spray orifice is accomplished by the utilization of a dual spray tip assembly 57 as shown in FIGURES 2 and 3. The spray tip assembly 57 is described in detail in United States Letters Patent No. 3,116,882 and is sold by the Gray Company, Inc. of Minneapolis, Minn. Briefly, this assembly comprises a generally ball-shaped member 58 which is positioned within the fitting 59 so as to permit relative rotation between the ball member 58 and the fitting, but prevents leakage of fluid therebetween. The fitting 59, which is attached to the end of the barrel 60 of the spray gun by a threaded nut 61, is generally cylindrical in shape and has an axial passageway 62 formed therethrough which, at one end, permits fluid communication between the ball member 58 and the fluid passage (not shown) formed in gun 24 and which, at the other end, provides an opening through which fluid may be sprayed from the gun. The ball member has two intersecting passages 63 and 64 drilled therein with longitudinal axes of the passages being spaced from each other. Thus, when one of the passages 63 and 64 is aligned with the passageway 62, the other passage is perpendicular to the passageway. Moreover, because of the close fit between the ball member 58 and the fitting 59, fluid only flows through the passage aligned with the passageway 62. The passages 63 and 64 have conventional spray orifices 65 and 66, respectively, positioned at one end thereof with the orifice 66 having a larger effective diameter than the orifice 65.

The ball member 58 includes a shaft 67 which projects up through a sleeve 68 formed on the fitting 59. The upper end of the shaft 67 has a handle 69 attached thereto by the lock nut 70. By rotating this handle through a 90 are, the user of the gun may select which of the two spray orifices 65 and 66 will be used for spraying. Of course, since these spray orifices have different effective diameters, and since the capacity or flow rate of the pump remains constant, the fluid pressure in the conduit 25 will depend on which of the orifices is being used to spray fluid.

As shown in FIGURE 1,

conventional check valves

71 and 72 are positioned in

conduits

16 and 18, respectively, so as to prevent back flow of fluid in those lines.

In a specific example of the improved fluid selection system of this invention, the pump 15 is a 550 p.s.i. pump having a two gallon per minute capacity at a maximum of 550 p.s.i. The spray orifice 65 has an effective diameter of 0.062 inch and at the flow rate of two gallons per minute, the pressure of the fluid in

conduits

25 and 42 is maintained at 450 p.s.i. The other spray orifice '66 has an effective diameter of 0.078 inch and at the flow rate of two gallons per minute, the pressure of the fluid in

conduits

25 and 42 is maintained at 160 p.s.i. The force of the spring 56 is selected so that when fluid is sprayed through orifice 65, and thus a pressure of 450 p.s.i. exists in

conduits

25 and 42, the force of the fluid acting on face 48 of the piston 45 overcomes the force of spring 56, and the piston 45 and thus valve assembly 51 are moved to the left from the position shown in FIGURE 1, thereby permitting additive fluid to flow from the tank 13 to conduit 16. Of course, the specific proportion of additive fluid in the mixture of additive and base fluid sucked into the pump inlet 14 depends on the setting of the adjustable restrictor 22.

When the user of the spray gun rotates the handle 69 so that the spray orifice 66 is used for spraying, the resultant fluid pressure in

conduits

25 and 42 is insufficient to overcome the force of the spring 56. Thus, the spring returns and retains the piston 45 and valve 52 to the position shown in FIGURE 1 and flow of additive fluid from the tank 13 to the pump inlet is stopped. At this time, only base fluid is sprayed from the gun.

Of course, rather than using the nozzle assembly 57 described above, the same functional results may be achieved by using separate spray tip assemblies having different effective diameter spray orifices. One assembly could be threaded onto the end of the barrel 60 of the spray gun 24 when the operator desires to spray base fluid alone and that assembly could be removed and another assembly threaded onto the end of the barrel when a mixture of additive and base fluid was to be sprayed. Of course, using separate spray tip assemblies would be more time consuming and cumbersome than using the assembly 57.

Therefore, in view of the above, it is apparent that the novel and improved fluid selection system of this invention provides an improved, simplified and trouble-free system for selecting whether the base fluid alone or a mixture of an additive and a base fluid will be sprayed from a spray gun. This system utilizes inexpensive, commercially available components and provides a reliable and relatively inexpensive system.

Moreover, it should be noted that while the improved fluid selection system of this invention has been described herein with reference to industrial spray cleaning equipment, the system may be used with other equipment. Furthermore, while in the preferred embodiment only two different fluids are shown, additional fluids may be used by incorporating additional valve means, similar to valve means 19, into the system which valve means operate in response to higher pump outlet pressures. Of course, additional spray orifices would have to be used so as to achieve the higher pump outlet pressure.

This invention may be embodied in other specific forms which do not depart from the spirit or essential characteristics thereof. The preferred embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing descriptions and all changes which come Within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

I claim as my invention:

1. An improved fluid selection system particularly adapted for use in industrial spray cleaning equipment comprising: a constant flow rate fluid pump having an inlet and outlet; nozzle means having a spray orifice for spraying fluid under pressure therefrom; first conduit means for connecting the pump outlet with the nozzle means; means for selectively maintaining the pressure of the fluid in the first conduit means at either a first pressure or a second pressure; a first source of fluid; a second source of fluid; second conduit means for connecting the first source of fluid with the pump inlet; third conduit means for connecting the second source of fluid with the pump inlet; and valve means, including fluid pressure responsive valve actuating means, for controlling the flow of fluid through the third conduit means; fourth conduit means for connecting the fluid responsive means of the valve means with the pump outlet whereby when the fluid in the first conduit means is maintained at said first pressure, a valve means permits flow of fluid through the third conduit means and when the fluid in the first conduit means is maintained at said second pressure, the valve means prevents the flow of fluid through the third conduit means.

2. The system described in claim 1 in which said first pressure is greater than said second pressure.

3. The system described in claim 1 including means positioned in the third conduit means for adjustably controlling the volume of fluid flow through the third conduit means, relative to the volume of fluid flow through the second conduit means.

4. The system described in claim 1 in which the valve means comprises a body in fluid communication with the third conduit means; a piston slidable in the body and having one face thereof in communication with the fluid in the first conduit means whereby the pressure of the fluid in the first conduit means biases the piston to a first position; spring means biasing the piston to a second position spaced from the first position; a valve element carried by the piston and a valve seat formed in the body and spaced from the piston whereby when the fluid in the first conduit means is at said second pressure, the piston is moved to the second position so that the valve element engages the valve seat and when the fluid in the first conduit means is at said first pressure, the piston is moved to the first position so that the valve element is spaced from the valve seat.

5. The system described in claim 1 in which the pressure maintaining means is carried by the nozzle means.

6. The system described in claim 1 in which the pressure maintaining means includes a member carried by the nozzle means and having first and second passages formed therein for fluid communication with the first conduit means; the passages being of different diameters; means for selectively placing either the first or second passage in fluid communication with the first conduit means whereby when the first passage is placed in communication with the first conduit means, the pressure of the fluid in the first conduit means is maintained at said first pressure and when the second passage is placed in communication with the first conduit means, the pressure of the fluid in the first conduit means is maintained at said second pressure.

7. The system described in claim 4 in which the central longitudinal axis of the valve element, the valve seat and the piston are coaxial.

8. The system described in claim 5 in which the pressure maintaining means includes means for changing the effective diameter of the spray orifice of the nozzle means.

9. The system described in claim 6 in which the member is ball-shaped and the terminal ends of the first and second passages form spray orifices for the nozzle means, and in which the eifective diameter of the spray orifice in the first passage is less than the effective diameter of the spray orifice in the second passage.

10. The system described in claim 9 in which the valve means comprises a body in fluid communication with the third conduit means; a piston slidable in the body and having one face thereof in communication with the fluid in the first conduit means whereby the pressure of the fluid in the first conduit means biases the piston to a first position; spring means biasing the piston to a second position spaced from the first position; a valve element carried by the piston and a valve seat formed in the body and spaced from the piston whereby when the fluid in the first conduit means is at said second pressure, the piston is moved to the second position so that the valve element engages the valve seat and when the fluid in the first conduit means is at said first pressure, the piston is moved to the first position so that the valve element is spaced from the valve seat.

References Cited UNITED STATES PATENTS 3,049,302 8/1962 Simmons 239-126 3,116,882 1/1964 Vork 239391 X 3,140,049 7/1964 Norstrud et a1. 239-126 STANLEY H. TOLLBERG, Primary Examiner.

US. Cl. X.R.