US2959358A

US2959358A - Portable pneumatic spray-painting unit

Info

Publication number: US2959358A
Application number: US693608A
Authority: US
Inventors: William D Vork
Original assignee: Individual
Current assignee: Individual
Priority date: 1957-10-31
Filing date: 1957-10-31
Publication date: 1960-11-08
Anticipated expiration: 1977-11-08

Description

Nov. 8, 1960 w. D. VORK PORTABLE PNEUMATIC SPRAY-PAINTING UNIT 6 Sheets-Sheet 1 Filed 001;. 51, 1957 mwN m w mm? 3 MWIW 2.; \\w h. a? 1 INVENTOR. MIL/AM D. Van:

BY W11 flrrae/vex Nov. 8, 1960 w. D. VORK 2,959,358

PORTABLE PNEUMATIC SPRAY-PAINTING UNIT Filed Oct. 31; 1957 6 Sheets-Sheet 2 IZQQ o n z/zzamp. Var? Nov. 8, 1960 w. D. VORK PORTABLE PNEUMATIC SPRAY-PAINTING UNIT 6 Sheets-Sheet 4 Filed Oct. 31; 1957 Nov. .8, 1960- w. D. VORK PORTABLE PNEUMATIC SPRAY-PAINTING UNIT 6 Sheets-Sheet 5 Filed 001:. 31, 1957 m hm fi NE INVENTOR.

MLLMM D. l aez BY (5 0f M fl'fi llv Nov. 8, 1960 w. D. VORK 2,959,358

PORTABLE PNEUMATIC SPRAY-PAINTING UNIT Filed Oct. 31, 1957 6 Sheets-Sheet 6 94 fflrevfor United States Patent C) PORTABLE PNEUMATIC SPRAY-PAINTING UNIT William D. Vork, Edina, Minn. Gray Co., Inc., 60 11th Ave. NE., Minneapolis 13, Minn.)

Filed Oct. 31, 1957, Ser. No. 693,608

7 Claims. (Cl. '239- -330) The present invention relates to new and useful pneumatically operated liquid dispensers and to spray-paint apparatus comprising an air-powered supply pump, and an air-atomizing spray-gun connected therewith, both perated from the same source of compressed air, and so arranged that the operation of the control-valve of the spray-gun will cause the supply pump to be charged and discharged.

In another aspect, the present invention also relates to spray-painting apparatus adapted for use particularly with original containers of paint, as, for instance,. 25- pound pails or other sized pails or drums, although, it is also suitable for like handling and dispensing of liquids other than paints, but which are to be dispensed in a manner similar to spray-painting.

In the accompanying drawings, in which like reference characters indicate like parts,

Figure 1 represents a perspective view of one embodiment of the present invention,

Figure 2 represents a top plan view of the same, on a somewhat larger scale,

Figure 3 represents a section on line 33 of Figure 2, on the same scale as that of Figure 2,

Figure 4 represents a section on line 44 of Figure 2,

but on a scale larger than that of Figure 2,

Figure 5 represents a section on line 5--5 of Figure 2, on the same scale as that of Figure 4,

Figure 6 represents a section on line 6-6 of Figure 2, on the same scale as that of Figures 2 and 3,

Figure 7 represents a section on line 7-7 of Figure 2, on the same scale as that of Figures 2, 3 and 6,

Figure 8 represents an offset partial section on lines 88 of Figure 2, on a scale slightly larger than that of Figure 2,

Figure 9 represents a fragmentary plan view on line 9-9 of Figure 4, on a scale the same as that of Figure 4, and

Figure 10 represents a vertical center cross-sectional view of the spray gun on line 10-10 of Figure l but on a scale substantially larger than that on which the spraygun is shownin Figure 1.

In the present embodiment of my invention shown in the drawings, the apparatus of the present invention includes an upper pneumatic housing member land a lower pump housing member 2-, the former dished upwardly as at 3 to :form the upperpneumatic' motor-chamher 4 and the latter disheddownwardly asat 5 to form the lower liquid or pump-chamber 6, from the inlet extension 7 of which the riser pipe 8 extends downwardly to the bottom of the container 9, from which the paint or other liquid is to be pumped (see Figures 3 and 8),

Between the housing members 1 and 2, a diaphragm clamping ring 10 is disposed, nested within the annular bore 11 in the upper housing member 1, and having the upper annular'flange 12of the lower housing member 2' nested'within it; the juxtaposed annular surfaces of the: ring'10' and flange 12 being tapered or conical, in the,

manner indicated in Figures 3 and 8. An 0 ring 14 within the ring-receiving groove 15 in the inner conical surface of the ring 10 forms a fluid-tight seal between the flange 12 of the lower housing member 2 and'. the

diaphragm-clamping ring 10. Between the slightly raised.

10 is preferably provided with an outer annular raised rib-like portion 18, of such height that when the ring 10 is firmly clamped to the housing member 1, the ring will not tend to twist, but will remain in its original plane; the height of the annular rib 18 being equal to the height of the raised inner annular lip of the ring 10 (which bears against the periphery of the diaphragm 17) plus the thickness of the diaphragm when tightly clamped.

A spring-plunger housing 19 extends upwardly from the raised pneumatic chamber portion 3 of the housing member 1, and is preferably formed integrally therewith, as indicated in Figures 3 and 8. The spring-chamber 20 (within the housing portion 19) is preferably coaxial with, the pneumatic chamber 4, pump-chamber 6 and dia pragm 17. The diaphragm 17 is flanked by supporting discs 102 and 103; A spring-plunger is disposed within the spring-chamber 20, and has a spring-anchorage head 35. The lower end of the plunger 100 extends through an opening in the bottom of the spring-chamber 20 (see Figure 3) and its reduced end 101 extends through thediscs 102 and 103 and through the diaphragm 17 and has a nut threaded thereonto, which firmly clamps the discs 102 and 103 (and the intervening portion of the diaphragm 17) between the nut and the down wardly facing shoulder on the plunger 100 '(between the reduced-diametered lower end 101 of the plunger andthe; Th6

portion of the plunger immediately above it). helical compression spring 32 is interposed between the head-like spring-abutment 35 at the top of the plunger 100 and the bottom of the spring-chamber 20 (inthe? manner indicated in Figure 3). The spring-chamber 20 is closed by the" upper screw-cap 33 which is; screwthreaded into the upper end of the chamber 20 and is sealed thereto by an. O ring or other'suitablesealing gasket, so thatthe spring-chamber-20*maintains the same pressure as that of the upper motor-chamber 4-"with which it freely communicates through the clearance 'be-' tween the plunger 100 and the hole in the bottom chamber 20 throughwhich' the plunger extends.

The diaphragm-clamping ring 10 maybe secured tothe of the upper housing member 1 (thereby to-clamp the diaphragm 17 by three or four

screws

21 and 22 alter-hat ing with each other as indicated in Figure 2, threadedinto corresponding threaded holes in the upper housing member 1, as indicated in Figure 8. The screws 21 may" be socket-headed screws (Allen screws) whose heads 23 nest inclearance-holes 24 inthe flange 25 of the lower housing. member 2 and whose stems extend" through clearance holes 26 in the ring 10; the heads 23 thereof clampingly engaging the ring 10; The screws 22"have two oppositev thread shanks anda hexagonal head 27 therebetween, The uppershanks of'the screws '22extend through clearance holes 26 in the ring 10 and preferably have lock-washers 28 between the heads 27 thereof and dished pump-chamber wall'5 thereof to the outer periphcry of the flange 25. In the upper side of the flange 25 clearance recesses 30 are provided for recessing the heads 27, while the lower shanks of the screws 22 extend through clearance holes in the flange 25. Wing type or other nuts 31 are threaded onto the lower shanks of the screws 22, to hold the lower housing member securely in place. Thus, by removing the nuts 31, the pump-housing member 2 may be removed from the pneumatic housing member 1 without disturbing the seal between the diaphragm 17 and the pneumatic housing 1; thereby permitting the cleaning of the pump.

The compressed air is supplied (through a hose, not shown) through the fitting 40 and through the screen 41, to the automatic pneumatic relay or controller designated generally by the numeral 42 (see Figures 3, 4 and 5).

The pneumatic relay 42 includes a cylinder 43, within which the piston 44 is operatively mounted, with the O ring 45, in the ring-receiving groove 46 thereof, forming a fluid-tight seal between the cylinder 43 and piston 44. The piston 44 acts as a movable pneumatic divider, to form a lower inlet chamber 47 on one side of the piston and an upper chamber 48 on the other side thereof; the latter being closed by the screw-cap 49 threaded into the housing 50 and sealed thereto by suitable ring 51, as indicated in Figures 3, 4 and 5.

The piston 44 is urged downwardly by the spring 52.

The piston 44 is provided with a central vertical bore 53, in the upper end of which a valve-seat 54 is provided, through which the ports 55 extend, for the passage of atomizing air from the upper chamber 48 (of the controller 42) through the passageway 86, the pressure-regulator 85 and the air-outlet 88 (Figure and through the hose 87 to the spray-gun 97 (Figure 1).

One or more passageways 56 are provided from the lower side of the piston 44 to the central bore or passageway 53 thereof, for the delivery of air, in full free flow, to the valve-seat 54 and port 55.

The piston 44 is provided with a bushing 57, threaded into the lower enlarged threaded end of the axial bore 53 thereof. The lower end 58 of the bushing 57 serves as a valve member, to cooperate with the valve-seat 59, which may be formed of a suitable non-metallic material such as an appropriate plastic (as for instance synthetic rubber) which may be held in place in the annular groove 60 in the main body of the pneumatic relay 42.

Through the bushing 57 a valve-stem 61 extends, having at its upper end the valve 62, which is adapted to seat against the valve-seat 54 to close the ports 55, and is urged against said valve-seat 54 by the spring 63, the opposite end of which abuts against the retainer or washer 64, which confines the O ring 65 within its ring-receiving groove or recess in the upper end of the bushing 57 (Figure 4); the O ring 65 serving to seal the valve-stem 61 in relation to the central bore of the bushing 57.

The hole through the valve-seat member 59 and the hole 66 in the wall 67 of the chamber 68, serve as an air-supply passage between the lower relay-chamber 47, on the one hand, extending from the chamber 68 to the lateral passageway 69 with the inlet-chamber 70 of the motor-air pressure-regulator 71, on the other hand (see Figure 4); through which pressure-regulator 71 air is supplied to the upper motor-chamber 4 for actuating the pump-diaphragm 17 in a downward (liquid-delivering) direction.

Through the lower wall 72 of the chamber 68, a port 73 extends, on the lower side of which is a valve-seat 74, facing towards the vent-chamber 75 (see Figures 4 and 5).

To the lower end of the valve-stem 61, a valve 76 is secured in the cup-shaped retainer 77, secured thereto by the nut 78 threaded onto the reduced-diametered threaded end 79 of the valve-stem 61. The valve member 76 may likewise be of plastic, such as synthetic rubber or the like (see Figure 5).

A vent opening 80 extends from the. vent-chamber 75 to the atmosphere. The closure plug 81, sealed by the O ring 82, serves to provide access to the vent-chamber 75 for the assembly of the valve elements 76, 77, and 78 upon the valve-stem portion 79.

Through the wall of the piston 44, one or more bleedcrholes 83 are provided, of such cross-sectional area that when the equipment is at rest, that is, when no air is drawn by the spraygun 97, the pressure of the air will be equalized on the opposite sides (47 and 48) of the piston 44, but of a cross-sectional area sutficiently small so that when the air-valve 108 of the spray-gun 97 (Figure 10) is opened, resulting in a drop in pressure in the air-line 87 (and passageways 88 and 86) leading to spray-gun 97, such pressure-drop will create a sufiicient pressure-differential (on opposite sides of the piston 44) urging the piston 44 upwardly towards the chamber 47 to overcome the force of the spring 52 so as to move the piston 44 upwardly.

The upper chamber 48 of the relay 42 communicates freely with the air-receiving chamber 84 of the sprayair pressure-regulator 85, through the passageway 86 (Figure 5), so that whenever there is a pressure-drop in the air-line 87 leading to the spray-gun 97 and in the air-outlet '88, the aforementioned unbalance is effected.

The air through the pressure-regulator 71 enters the air-chamber 4 of the diaphragm motor, through the passageway 89, as shown in Figure 4.

When the air-control-valve 108 of the spray-gun 97 is closed and the air-supply (through 40, 41, 95, 96, 47 and 66) to the pressure-regulator 71 is consequently shut oh and the pressure-regulator 71 is vented to the atmosphere by the seating of the valve-face 58 of the bushing 57 against the valve-seat-gasket 59 and by the unseating of the venting-valve 76 from the valve-seat 74 (due to the equalization of the air-pressure on opposite sides of the piston 44, through the bleeder-hole 83, and the hence unopposed force of the spring 52), the air-valve 90 of the regulator 71 is entirely open; being urged downwardly by the spring 91 which overcomes the relatively much Weaker valve-seating spring 123 urging the valve 90 towards the lower valve-face of the bushing 148 at the same time the valve 92 of the spray-air regulator is closed by the air-pressure retained in the hose-line 87, which pressure unbalances or overcomes the spring 93; the pressure in the hose '87 (and in the passageways 88 and 132 and chambers 131 and 128) being first increased sufficiently to overcome the spring 93, by a flow of supply-air while the valve 92 is still unseated by the pressure-drop in the hose 87 (due to the previous opening of the air-valve 108 in the spray-gun 97, but which valve 108 had then been closed), until the pressure in the chambers 131 and 128 and in the hose 87, acting on the diaphragm 125, has risen to a point suflicient to overcome the spring 93.

In this rest position, no compressed air is supplied to the air-chamber 4 of the diaphragm motor, and the air-chamber 4 is vented to the atmosphere. Hence, no air pressure is exerted upon the paint (or other liquid) in the pump-chamber 6 tending to deliver it to the gun 97, although the paint (or other liquid) is contained within the hose 94 and in the

passageways

112 and 113, above the check valve 176 in the tubular valve member 163 (Figures 3 and 6), is retained in such hose at whatever pressure it was delivered.

The apparatus of the present invention operates as follows:

Compressed air supplied through the fitting 40 (Figure 5), after passing through the filter 41 into the air-distributing chamber 95, passes upwardly into the lower chamber 47 of the relay 42, beneath the piston 44 (through the passagewav 96). When no air is discharged through the spray-gun 97 (Figures 1 and 10), namely. when its valve-actuating trigger-lever 98 is in its off position, the pressure in the air-passage 88 (leading to the air hose 87) builds up until it is sufficiently high to amass.

overcome the spring 93 of the spray-air regulator 85 (when the valve 92 closes), and the air-pressure in the passageway 86 and the upper chamber 48 of the relay 42, on the one hand, and the air-pressure in the lower chamber 47 of the relay 42, on the other hand, become equalized through the bleeder-hole or holes 83 through the wall of the piston 44 of the relay. In this condition of pneumatic equality below and above the piston 44, the spring 52 of the relay forces the piston 44 downwardly, thereby seating the movable valve-seat 54 at the upper end of the bore 53 in the piston 44, against the valve 62 carried at the upper end of the valve stem 61, and forcing the valve stem downwardly against the force of the weaker spring 63, until the movable valve-face 58 at the bottom of the bushing 57, carried by the piston 44, seats against the stationary valve-seat member 59. In this lower or non-spraying terminal or limiting position of the piston 44, the vent-valve 76 is unseated from its stationary valve-seat 74, thereby venting the upper pneumatic chamber 4 of the diaphragm-motor. In the so vented condition of the upper pneumatic chamber 4 of the diaphragm-motor, the recharge-plunger 100, within the plunger-chamber 20, whose lower end 101 is secured to the center of the diaphragm 17 and to the central supporting discs 1G2 and 103 thereof, moves the diaphragm upwardly under the influence of the recharge compression spring 32, to exhaust the air from the pneumatic chamber 4 above it and to draw a charge of paint or other liquid into the pump-chamber 6 beneath it (through the riser 8), as indicated in Figure 3.

The plunger and spring housing 19 is hermetically sealed at its upper end by means of the screw-cap 33, which is sealed thereto by a suitable 0 ring or other gasket 34. The plunger 100' has an upper flange 35 against which the upper end of the compression-spring 32 is adapted to hear, so as to urge the plunger upwardly.

This upward movement of the diaphragm 17 will take place irrespective of how far down the diaphragm happens to be at the time, and irrespective of the extent to which the liquid contained within the chamber 6 has been expelled through the liquid hose 94.

When the trigger 98 of the spray-gun 97 is' moved in its opening direction, namely, in the direction of the arrow 104 (Figures 1 and 10), thereby opening the aircontrol valve 108 of the spray-gun 97, which admits air into the head 1115 of the gun 97, to discharge it through the nozzle member 106 in atomizing juxtaposition to the liquid stream being simultaneously discharged therethrough, then the flow of air through the air-passage 88, the spray-air pressure-regulator 85 and the passage 86 (in excess of the flow through the bleeder-holes 83 in the piston 44 of the relay 42) causes a pneumatic unbalance between the top and bottom chambers 48 and 47 (above and below the piston 44 of the relay 42), namely, the pressure in the upper chamber 48 drops substantially below the line-pressure in the lower chamber 47 supplied through the fitting 40, because the bleeder-hole or holes 83 are of such small cross-sectional area that they do not permit a flow sufiicient to satisfy the air requirements or air consumption of the spray-gun 97 without av pressure-drop across such bleeder-hole (or holes) 83.

This drop in pressure above the piston causes the incoming supply-air to force the piston 44 upwardly against the force of the spring 52 (which is compressed thereby). This upward movement of the piston 44 seats the ventvalve 76 against its valve seat 74, thereby to stop the venting of the pneumatic chamber 4 of the diaphragm motor to the atmosphere, and at the same time unseats the movable valve 53 carried by the piston 44 from its stationary valve-seat 59, thereby to admit air at the supply-pressure into the chamber '68 which is the terminal portion of the passageway 69, through which the so admitted air (passing through the hole 66 in the wall 67) passes to and past the valve 90 of the motor-airpressure-- regulator 71, which valve 90 is normally unseated or held open by the spring 91 until the pressure inthe pas: sage 89 builds up to the predetermined amount at which the pressure controller is set. The air then passes down through the passageway 89 into the upper pneumatic" chamber 4 of the diaphragm-motor (above the diaphragm 17 thereof) and forces the diaphragm downwardly against the upward pull of the spring 32 (which is compressed thereby), and causes the liquid beneath the diaphragm to be expelled through liquid-discharge outlet 110 and volume between the uppermost and lowermost positions of the diaphragm 17 (determined by the abutment of the upper diaphragm-disc 102 against the uppermost inner surface of the pneumatic chamber 4, as shown in Figure 3, and by the abutment of the outer peripheral zone of the lower diaphragm disc 103 against the annular shoulder 116 in the pump chamber 6) is such that the spraygun 97 may be operated continuously for a substantial length of time without exhausting the liquid which the apparatus is capable of delivering with a single passage or movement of the diaphragm from its uppermost to its lowermost position. However, it is not necessary to exhaust the full single charge of liquid, but the sprayingv may be interrupted by releasing the trigger 98 of the spray-gun 97 at any time before such paint supply of a single charge is exhausted, and upon the release of the gun trigger, the pneumatic operation hereinabove described is repeated by the seating of the valve 58 against its seat 59 to shut off the supply-air to the pneumatic chamber 4 of the diaphragm motor and by venting such chamber by the unseating of the venting valve 76, where upon the spring-powered plunger 100- moves the diaphragm upwardly and again refills the liquid chamber'ti to its maximum capacity, through the riser 8, namely,

it replaces whatever liquid has been previously discharged from liquid chamber 6.

The rate of air flow (through the passage 89 into the upper pneumatic chamber 4) is comparatively. low (be-. cause the rate of liquid delivery to thegun is compara tively low), and only a small discharge port is required between the regulator chamber 118 and the passageway 89 leading to the pneumatic chamber 4 of the diaphragmmotor (Figure 4). On the other hand, a rapid venting of the air (through the passage 89, chamber 118, passage 69, ports 66 and 73 and vent helps to obtain an instantaneous recharging of theliquid chamber 6 whenever the spraying operation stops, if even for a very. To provide a slow delivery of operating being held against the fiat surface 121 in the bottom of. the pneumatic chamber 118 of the pressure-controller. 71, by means of a screw 122. Thus, when the shutting;

off of the spray-gun 97 causes the seating of the supply-.

valve 58 (which supplies the air to the diaphragm-motor) and the unseating of the venting valve 76, so as to. permit the diaphragm 17 to be moved upwardly to exhaust the air above it and to draw in liquid beneath it, the air-can pass the reed-valve 119 by raising it off its seat (which is the fiat bottom surface 121 of the chamber 118) so that the upward charging motion. of the diaphragm 17 may.

be rapid.

The distances between the seating and unseating posia tions of the valves (58, 76 and 62) governed by the relay. 42 is such that when the spray-gun 97 is operating, namely, when its air valve 108 is open, and when, coii sequently, the piston 44 of the relay 42 is in its uppermost position and the vent-valve 76 has been seated or closed," the motor-air supply-valve '8 has been unseated or opened (so as to admit air to the motor-air pressure-regulator 71) and the spray-air supply-valve 62 at the top of the valve-stem 61 has been opened by being left behind by its valve-seat 54 (which is moved still further in an upward direction) thereby uncovering the port or ports 55 at the top or upper end of the central axial passageway 53 in the piston 44, so as to permit a full free flow of air, at or near the original supply-pressure, to the spray-air pressure-regulator 85 and through it to the air-outlet passageway 88 and to the air-hose 87 (through the shut-off valve 124).

The pressure-regulator 85 includes a diaphragm 125 urged downwardly by its spring 93, the force of which may be varied by the screw 126 and the cap-like handle 127 thereon (as indicated in Figure 5); the diaphragm 125 being sealed to the housing of the pressure-regulator by suitable gasketing or otherwise, so that an air-tight pneumatic chamber 128 is formed beneath the diaphragm 125, and above partition-wall 129. Partition-wall 129 is provided with one or more bleeder-holes 130 therethrough for permitting the equalization of pressure between the chamber 128 above the partition-Wall 129 and the lower chamber 131 therebeneath, from which the air passes to the outlet 88 through the passageway 132, and which chamber 131 communicates with the passageway 86 through the passageway 133 in the valve-seat bushing 134. A valve-operating rod 135 extends from the diaphragm 125, through a suitable rod-guiding sleeve in the partition 129, and bears against the top of the movable valve 92, so as to depress it against the force of the valve-closing spring 136 and thereby to open it by unseating it from the stationary valve-seat at the bottom of the bushing 134.

When the spray-gun 97 is shut ofi, the pressure in the air-hose 87, in the air-outlet passage 88 and in the chambers 131 and 128 builds up until, acting upwardly on the diaphragm 125, it is sufficient to move the diaphragm up sufliciently to permit the seating of the valve 92. In normal operation, the valve 92 maintains a position, in relation to the stationary valve seat thereof, just sufficient to maintain the predetermined desired pressure in the air-hose 87 and in the head 105 of the gun 97 regardless of the rate of air flow. Thus, as the rate of flow increases, thereby tending to reduce the pressure in the chamber 131 of the regulator 85, such pressure drop is transmitted to the upper chamber 128 through the bleeder-holes 130, and this reduction of pressure on the lower side of the diaphragm 125 causes the spring to move the diaphragm 125 down and to further open the valve 92 to admit more air therethrough. Conversely, when the air demand of the gun 97 is gradually decreased, this causes a corresponding increase in pressure in the chambers 131 and 128 and causes the diaphragm to be moved upwardly, thereby to reduce the extent to which the valve 92 is unseated; thereby to maintain the desired air-pressure in the head of the gun.

The motor-air pressure-controller 71 (Figure 4) likewise includes a diaphragm 139, sealed to the housing thereof, to form an air-tight chamber 140 therebeneath, which communicates with the aforementioned chamber 118 thereof through vent holes 141 in the partition-wall 142, which is similar to the partition-wall 129 of the pressure-regulator 85. The diaphragm 139 and its supporting disc 143 are held in assembled relation by a tubular flanged bushing 144 which extends therethrough and which is held assembled by the nut 145. At the lower end of the axial hole through the bushing 144, a valve-seat 146 is provided, against which the upper valveend of the valve-stem 147 is adapted to bear when the diaphragm moves downwardly to unseat the valve 90 against which the stem 147 bears or with which it is Connected.

When the venting-valve 76 is open (as indicated in Figure 5) and when the motor-air supply-valve 58 is closed, the spring 91 moves the diaphragm 139 downwardly to seat the upper valve-end of the valve-stem 147 against its valve seat 146, and also to unseat the valve from its stationary valve seat at the bottom of the valve bushing 148. When the venting valve 76 is seated, however, and motor-air supply-valve 58 is unseated, the air entering upwardly through the bushing 148 (past the unseated valve 90) exerts an upward pressure on the diaphragm 139, while at the same time the air passes downwardly through the passage 89 into the pneumatic chamber 4 of the diaphragm-motor. This upward pressure on the diaphragm tends to compress the spring 91, so that as the pressure increases, the diaphragm moves upwardly and permits the valve 90 to approach its valve seat more closely and thus reduce the flow of air and indeed shut it off entirely if the pressure increases beyond the setpoint pressure, as, for instance, when the diaphragm 17 has reached the lowest position of its permissible travel. In its uppermost position the valveseat 146, carried by the diaphragm 139, may leave the valve-end of the valvestem 147 behind (after the valve 90 is firmly seated against the bushing 148), thereby permitting the escape of air through the axial vent-hole in the bushing 144. The air pressure so delivered to the diaphragm-motor is regulated to any desired constant value or set point pressure by the adjustments of the screw 150 through the cap-like handle 151 thereon. Thus, the more the spring 91 is compressed by said screw, the greater will be the pressure delivered to the pneumatic chamber 4, of the diaphragm-motor.

The liquid-discharge valve-housing 111 (Figures 3, 6 and 7) includes a lower receiving chamber having a return port 161 extending downwardly therefrom, and a valve seat 162 at the upper end of the return port 161.

A generally tubular valve member 163 having a portion thereof externally threaded (as indictaed in Figures 3 and 6) is screw-threadedly mounted within the receiving chamber 160 and the outlet chamber 112 of the valvehousing 111 and in the internally threaded bore 164 of the housing 111. The lower end 165 of the generally tubular valve member 163 is closed and is conical, or otherwise suitably shaped to serve as a movable valve cooperating with the stationary valve seat 162, to close or open the liquid-return port 161, as the case may be. Into the upper enlarged bore of the valve member 163 a cylindrical plug 166 is telescoped and is sealed thereto by an 0 ring within a ring-receiving groove in the cylindrical plug, as indicated in Figures 3 and 6, while a keying cross-pin 167 extends through the plug 166 and through the contiguous walls of the valve member 163 thereby to key the plug 166 to the valve member 163 against relative rotation in respect thereto. The upper end of the plug 166 is provided with a fiat transverse diametrically extending projection 168 which nests in the corresponding slot 169 in the lower end of the revolubly mounted and vertically movable valve-operating shaft or rod 170, which extends loosely through a hole in the outer flange-portion 13 of the upper pneumatic housing 1, as indicated in Figures 3 and 6, and is held against complete removal by any suitable 0 ring 171 or E ring snapped into an annular groove near the lower end of the shaft 170, as indicated in Figure 3. The shaft is pro vided with a handle-bar 172 by which it may be turned in either direction, thereby correspondingly to turn the tubular valve member 163.

The valve member 163 is provided with radial apertures 173 near its lower end, immediately above the lower conical valve end 165 thereof, through which apertures the liquid may enter from the receiving chamber 160 into the interior bore of the valve member 163. At a suitable point along its vertical extent, the bore as well as the exterior of the tubular valve member 163 is enlarged, as indicated in Figure 3, and an upwardly facing valve seat 175 is provided between its lower smaller-diametered bore and its upper larger-diametered bore, against which the ball check valve 176 seats (by gravity or otherwise), with its upward or unseating travel limited by the lower end of the plug 166. Radial apertures 177 are provided through the side-wall of the tubular valve member 163, above the valve seat 175 thereof and beneath the lower end of the plug 166, whereby the liquid may pass radially outwardly from the inner bore of the tubular valve-member 163 into the delivery chamber 112 of the valve housing 111. The upper enlarged cylindrical portion of the tubular valve member 163 (into which the plug 166 is telescoped) is revolubly and movably sealed to the contiguous upper cylindrical bore 174 in the valve-housing 111, by an O ring in a ring-receiving groove in the upper enlarged tubular cylindrical portion of the valvemember 163, as indicated in Figure 3.

When the tubular valve member 163 is screwed down (by means of the shaft 170 and handle 172) until the valve-end 165 thereof seats against the valve-seat 162, it closes off the return port 161. In this position, which is the normal position in the operating condition of the apparatus, the liquid being delivered through the passage.

110 and into the receiving chamber 160, passes inwardly through the radial holes 173 and upwardly through the bore of the valve member 163 and past the check-valve 176, which is thereby unseated from its valve-seat 175, outwardly through the radial holes 177 into the delivery chamber 112 of the valve-housing 111, from whence it passes laterally (as indicated in Figure 6) to the fitting 114 which telescopes into a registering hole 113 in the upper housing member 1, to which it is sealed by the ring 178 in a ring-receiving groove in the lower end of the bore 113 (Figure 7).

A valve-bushing 179 is provided on the inside of the intake member 7 of the lower pump housing 2 (Figures 3 and 8), having an upwardly facing valve seat 180, against which the ball check valve 181 is adapted to seat (by gravity or otherwise); the upward or unseating movement of said check valve being limited by the cross-pin 1 82. The liquid enters the lower end of the riser 8 through the screen 183 held in a suitable screen fitting 184. The liquid is drawn upwardly past the check valve 181 (which is unseated by the upward flow of liquid) whenever the diaphragm 17 moves upwardly to any extent. During such upward movement the liquid-discharge check-valve 176 is seated, so as to prevent the return flow of liquid. During any downward movement of the diaphragm 17, the intake check valve 181 is seated, and the outlet check valve 176 is usseated, thereby causing the delivery of the liquid from the pump-chamber 6 into the liquid outlet 113 through the shut-off valve 115 and through the hose 94 to the liquid passageways 109 in the head 106 of the gun 97, from where it is discharged through the orifice 99, controlled by the needle-valve 117 operated by trigger 98 in synchronism with the air-valve 108 likewise controlled by trigger 98 (see Figure When it is desired to clean the pump-chamber 6 and the riser 8 as well as the valve-housing 111 and valve member 163, the valve shaft or rod 170 is turned so as to unscrew the valve member 163 in an upward direction, thereby to unseat the valve end 165 thereof from the valve-seat 162. This permits the flow of liquid back into the container 9 (or into any other container on which the apparatus may be mounted). By then operating the gun, so as to discharge air therethrough, the diaphragmmotor is caused to go through its charging and pumping operation in the manner indicated heretofore, but with the result that the liquid drawn in through the riser 8 is returned to the container through the return port 161, with out delivering any liquid to the gun. to drain the liquid out of the hose 94 and out of the head of the gun, then the valve member 163 is raised still further until the intermediate radial holes 185 therein are raised above the internally-threaded bore 164 of the valve- If it is desired also 10 housing 111, so as to permit the liquid to flow backwardly through the passageway or chamber 112 into the holes and down through the bore of the valve member 163 and outwardly through the radial holes 173 and then past the valve seat 162 and out through the return port 161. The axial distance between the radial holes 173 and the radial holes 185 is such that when the radial holes 185 are raised above the internally-threaded bore of the valvehousing 111, the radial holes 173 will still be beneath such internally-threaded bore. When it is desired to put the apparatus into its operating condition, the valve member 163 is screwed downwardly again until the valve-end 165 thereof is firmly seated against the valve seat 162.

A rotary air motor 190, of either the single vane or multi-vane type, is carried by the lateral flange-portion of the upper pneumatic housing 1, as indicated in Figures 1, 2 and 3, with its axis at an angle as indicated particularly in Figures 1 and 3, with its shaft 191 extending down. through a suitable angled or inclined bore in the raised portion 192 of the flange, and is connected with the propeller shaft 193 by any suitable coupling sleeve 194 secured to the respective shafts by screws 195 and 196, respectively. "To the lower end of the shaft a propeller 197 is secured in juxtaposition to the intake fitting 184 at the bottom of the riser 8, thereby to agitate the paint or other liquid so as to deliver the liquid with uniform solid content (pigment or the like).

From the air-distributing chamber 95 in which the screen 41 is housed (Figures 2, 3, 4 and 5), a lateral passageway is provided to which the fitting 198 is secured (see Figures 2 and 1), from which a conduit, as for instance, copper tubing 199, extends to and is connected with the inlet valve 200 connected with the inlet 201 of the air-motor 190. A manually adjustable needle valve or similar control valve 202 serves to regulate the speed of rotation of the motor or to shut it off, if desired, by turning the knurled knob 203 thereof. Air from the motor is exhausted through the exhaust-fitting 204.

The apparatus may be mounted on any suitable container, as, for instance, a sheet metal pail or drum 9, having a beaded or similar upper flange 205 (Figures 3 and 8). A pair of diametrically opposed securing de vices designated generally by the numeral 206 is hingedly mounted on top of the outer flange-like portion ofthe upper pneumatic housing 1. Each of these includes a pair of hinge or pivot posts 207 extending upwardly from the housing member 1 and preferably formed integral therewith, which carry the horizontal pivots 208, which may be held therein by being headed at one end and having a cotter-pin extending through the other free end thereof.

Upon the pivots 208, the pair of levers 209 is pivoted, as indicated in Figure 8 the upper ends of the levers being olfset toward each other and having a handle-bar 210 extending therethrough and secured thereto.

The spaced-apart lower portions of each pair of levers 209 has a pivot 211 extending therethrough and riveted or otherwise secured thereto. The pivots 211 are disposed above pivots 208 and preferably inwardly therefrom, and the lower ends 212 of the levers are at a distance from the pivots 208 and 211 and are so spaced in relation thereto, that when the lower ends 212 bear against the upper surface of the flange of the upper housing member 1, as indicated in Figure 8, the straight line between the center of the pivot 211 and the bead 205 will pass between the pivot 208 and the contact point 212. A bead-engaging member 213 is provided between each pair of levers 209, with its upper end 214 looped around the pivot 211 and so pivotally secured thereto, and having a lower bead-engaging hook-like terminal portion 215 which is adapted to engage beneath the bead 205 and to pull upwardly thereagainst when the levers are swung inwardly in the direction of the;

arrows 216.

When the hooks are so engaged, not only is the"-ap-- 11 paratus firmly secured to the container, but the handlebars 210 also serve as carrying handles for the apparatus as well as the container in which the liquid is contained.

If desired, a manually operable vertically reciprocable agitator rod may be extended through and slidably mounted in an inclined bore extending through the upper housing member (in lieu of the rotary air-motor and propeller). To the lower end of such agitator rod, a suitable flat or dished disc may be secured, by which the liquid may be suitably agitated by the downward reciprocation of the rod.

The spray-gun 97 is shown in cross-section in Figure only for purposes of illustration and to show the airpassageway and the liquid passageway therein and the valves controlling the same. Thus, the spray-gun 97 has an air passageway 107 having a valve 108 therein operated by a trigger 98, and has a liquid passageway 109 therein controlled by the valve 117, which is likewise operated by the trigger 98; the trigger being pivoted at 137. The needle valve 138 adjusts the air supplied to the outer air jets in the nozzle 106. It is to be understood that any other spray-gun may be used with air and liquid passages and air and liquid valves.

It is to be understood that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and it is therefore desired that the present embodiment as hereinabove described and as shown in the accompanying drawings be considered as illustrative and not restrictive, reference being had to the claims rather than to the foregoing description to indicate the scope of the invention.

Having described the invention, the following is claimed:

1. Liquid spraying apparatus for spraying liquids and for dispersing the sprayed liquid with compressed air and for drawing the liquid from a container in which it is substantially at atmospheric pressure, said apparatus including a housing having a pump chamber and an airmotor chamber adjacent to each other and separated from each other by a flexible partition whose flexing in one direction enlarges one chamber and correspondingly reduces the other chamber and whose flexing in the other direction enlarges the latter chamber and reduces the former chamber, resilient means urging said flexible partition in the direction reducing the motor chamber and enlarging the pump chamber, a liquid intake in said housing leading to said pump chamber, an inwardly opening check valve controlling said intake, a liquid outlet in said housing leading from said pump chamber, an outwardly opening check valve controlling said liquid outlet, a supply-air inlet in said housing adapted for connection with a source of compressed air, a spray-air outlet in said housing adapted for connection with the air passageway of a spray gun, a liquid outlet in said housing adapted for connection with a liquid passageway of such spray gun, a pneumatic controller intermediate said supply-air inlet, said motor chamber and said spray-air outlet and having a motor-air-supply valve and a motor-venting valve communicating With said motor chamber and a spray-air-supply valve communicating with said spray-air outlet, and means in said pneumatic controller responsive to the air-flow and the cessation of air-flow through said spray-air outlet, for opening said spray-air-supply valve and said motor-air-supply valve and closing said motor-vent valve when the pressure drops in said spray-air outlet and for closing said sprayair-supply valve and said motor-air-supply valve and for opening said motor-vent valve when air-flow through said spray-air outlet is stopped.

2. Liquid spraying apparatus for spraying liquids and for dispersing the sprayed liquid with compressed air and for drawing the liquid from a container in which it is substantially at atmospheric pressure, said apparatus including a housing having a pump chamber and an air- Inotor chamber adjacent to each other and separated fi'om each other by a flexible partition whose flexing in one direction enlarges one chamber and correspondingly reduces the other chamber and whose flexing in the other direction enlarges the latter chamber and reduces the former chamber, resilient means urging said flexible partition in the direction reducing the motor chamber and enlarging the pump chamber, a liquid intake in said housing leading to said pump chamber, an inwardly opening check valve controlling said intake, a liquid outlet in said housing leading from said pump chamber, an outwardly opening check valve controlling said liquid outlet, a supply-air inlet in said housing adapted for connection with a source of compressed air, a spray-air outlet in said housing adapted for connection with the air passageway of a spray gun, a liquid outlet in said housing adapted for connection with a liquid passageway of such spray gun, a pneumatic controller intermediate said supply-air inlet, said motor chamber and said sprayair outlet and having a motor-air-supply valve and a motor-venting valve communicating with said motor chamber and a spray-air-supply valve communicating with said spray-air outlet, a pressure-regulator intermediate said motor-air-supply valve and said air-motor chamber, a pressure-regulator intermediate said spray-airsupply valve and said spray-air outlet and means in said pneumatic controller responsive to the air-flow and the cessation of air-flow through said spray-air outlet, for opening said spray-air-supply valve and said motor-airsupply valve and closing said motor-vent valve when the pressure drops in said spray-air outlet and for closing said spray-air-supply valve and said motor-air-supply valve and for opening said motor-vent valve when airflow through said spray-air outlet is stopped.

3. Liquid spraying apparatus for spraying liquids and for dispersing the sprayed liquid with compressed air and for drawing the liquid from a container in which it is at substantially atmospheric pressure, said apparatus including a housing having a liquid pump chamber and a compressed-air motor chamber adjacent to each other and separated from each other by a movable motor-andpump partition member therebetween whose movement in one direction enlarges one chamber and correspondingly reduces the other and whose movement in the other direction enlarges the latter chamber and reduces the former chamber, a liquid intake in said housing leading to said liquid pump chamber and an inwardly opening check valve controlling said intake, a liquid outlet in said housing leading from said liquid pump chamber and an outwardly opening check valve controlling said liquid outlet, a spring urging said motor-and-pump partition member in the direction enlarging the pump chamber and reducing the motor chamber, a spray gun having an air passageway therethrough and a liquid passageway therethrough, and an air shut-ofi valve in said air passageway and a liquid shut-off valve in said liquid passageway, and having a manual valve-operator for opening and closing said shut-off valves in said spray gun, a flexible hose interconnecting the liquid passageway of said spray gun with the aforementioned liquid outlet of the aforementioned pump chamber, a pneumatic controlvalve having a supply-air inlet, an inlet chamber in free communication therewith and a spray-air-supply chan1- ber adjacent thereto, a movable control partition member between said two chambers, said inlet chamber communicating with said motor chamber through a valved motor-air-supply port controlled by said control partition member, a valved spray-air-supply port between said two chambers controlled by said control partition member, a valved motor-venting port in communication with said motor chamber and controlled by said control partition member, said spray-air-supply chamber communicating with the air passageway of said spray gun, a spring urging said control partition member to close the aforesaid motor-supply-air valve and said spray-air-supply valve and to open said motor-venting valve, and bleeder- 13 passageway between said inlet chamber and said sprayair-supply chamber, of an effective cross-sectional area such that when the control valve of the spray gun is opened a differential pressure is created between said two chambers sufiicient to move said control partition member against its spring and to open said spray-airsupply valve and said motor-'air-supply valve and to close said motor-vent valve.

4. Liquid spraying apparatus for spraying liquids and for dispersing the sprayed liquid with compressed air and for drawing the liquid from a container in which it is at substantially atmospheric pressure, said apparatus including a housing having a liquid pump chamber and a compressed-air motor chamber adjacent to and facing each other, a diaphragm between said chambers and separating them from each other, a liquid intake in said housing leading to said pump chamber, an inwardly opening check valve controlling said intake, a liquid outlet in said housing leading from said pump chamber, an outwardly opening check valve controlling said liquid outlet, a spring urging said diaphragm in the direction enlarging the pump chamber and reducing the motor chamber, a spray gun having an air passageway therethrough and a liquid passageway therethrough, and an air shut-off valve in said air passageway and a liquid shut-ofl valve in said liquid passageway and having a valve-operator for opening and closing said shut-ofl valves, a flexible hose interconnecting the liquid passageway of said spray gun with the aforementioned liquid outlet of the aforementioned pump chamber, a pneumatic controller having a supply-air inlet, an inlet chamber in free communication therewith and a spray-air-supply chamber adjacent thereto, a movable control partition member between said two chambers and separating them from each other, said inlet chamber communicating with said motor chamber through a valved motor-air-supply port controlled by said control partition member, a pressure-regulator intermediate said valved motor-air-supply port and said motor chamber, a valved spray-air-supply port between said two chambers controlled by said control partition member, a valved motorventing port in communication with said motor chamber and controlled by said control partition member, a pressure-regulator having its intake side connected with said spray-air-supply chamber, a flexible hose interconnecting the outlet of said pressure-regulator with the air passageway of said spray gun, a spring urging said control partition member to close the aforementioned motor-supply-air valve and said spray-air-supply valve and to open said motor-venting valve, and bleeder-passageway through said control partition member, of an eliective cross-sectional area such that when the control valve of the spray gun is opened a differential pressure is created between said two chambers sufficient to move said control partition member against its spring and to open said spray-air-supply valve and said motor-air-supply valve and to close said motor-vent valve.

5. Liquid spraying apparatus for spraying liquids and for dispersing the sprayed liquid with compressed air and for drawing the liquid from a container in which it is substantially at atmospheric pressure, said apparatus including an upper pneumatic housing and a lower liquid pump housing, a motor chamber in said pneumatic housing and a pump chamber in said lower pump housing, said two chambers facing each other, a flexible partition between said two chambers and separating them, means for detachably securing said two housing members to each other, a spring-plunger chamber on said upper pneumatic housing member communicating with said motor chamber, a plunger in said spring-plunger chamber having its lower end secured to said flexible partition, and a spring in said spring-plunger chamber urging said plunger and said flexible partition upwardly.

6. Liquid spraying apparatus for spraying liquids and for dispersing the sprayed liquid with compressed air and for drawing the liquid from a container in which it is substantially at atmospheric pressure, said apparatus includ ing an upper pneumatic housing and a lower liquid pump housing, a motor chamber in said pneumatic housing and a pump chamber in said lower pump housing, said two chambers facing each other, a flexible partition between said two chambers and separating them, means for detachably securing said two housing members to each other, a spring-plunger chamber on said upper housing member communicating with said motor chamber, a plunger in said spring-plunger chamber having its lower end secured to said flexible partition, a spring in said spring-plunger chamber urging said plunger and said flexible partition upwardly, a discharge-and-return valve-housing communicating with said pump chamber and having a return port adapted for returning the liquid to its original source, a valve member movably mounted in said valve-housing and including means for controlling said return port and a discharge check valve, and means for by-passing said check valve when the return port is opened by the movement of said valve member.

7. Liquid spraying apparatus for spraying liquids and for dispersing the sprayed liquid with compressed air and for drawing the liquid from a container in which it is substantially at atmospheric pressure, said apparatus including an upper pneumatic housing and a lower liquid pump housing, a motor chamber in said pneumatic housing and a pump chamber in said lower pump housing, said two chambers facing each other, a flexible partition between said two chambers and separating them, means for detachably securing said two housing members to each other, a spring-plunger chamber on said upper housing member communicating with said motor chamber, a plunger in said spring-plunger chamber having its lower end secured to said flexible partition, a spring in said spring-plunger chamber urging said plunger and said flexible partition upwardly, a liquid-discharge outlet on said upper pneumatic housing, a discharge-and-return valve-housing communicating with said pump chamber and having a return port adapted for returning the liquid to its original source, a valve member movably mounted in said valve housing including means for controlling said return port and a discharge check valve, and means for by-passing said check valve when the return port is opened by the movement of said valve member, and a quickly connectable and disconnectable sealed telescoping connection between said valve-housing of said lower housing member and the liquid outlet of said upper liquid pump housing and said liquid-discharge outlet on said upper pneumatic housing.

References Cited in the file of this patent UNITED STATES PATENTS