US3633829A

US3633829A - Multistage sprayer

Info

Publication number: US3633829A
Application number: US39634A
Authority: US
Inventors: George R Adams
Original assignee: Adams Equipment Co Inc
Current assignee: Adams Equipment Co Inc
Priority date: 1970-05-22
Filing date: 1970-05-22
Publication date: 1972-01-11
Anticipated expiration: 1989-01-11

Abstract

A multistage sprayer utilized for cleaning, coating, and etching metals prior to painting adapted to serially clean the surface to be painted with a soap solution at a relatively high pressure, rinse the cleaned surface, coat the surface with a zinc phosphate-nitric acid solution at a relatively low pressure, rinse the phosphatized surface, and finally etch the surface with an acid solution for strengthening corrosion resistance. The sprayer incorporates a novel injector arrangement to obtain emission of a 20 percent zinc phosphate solution at a substantially relatively decreased line pressure for safe, effective phosphatizing.

Description

United States Patent [72] Inventor George R. Adams Florissant, Mo. [211 App]. No. 39,634 [22] Filed May 22, 1970 [45] Patented Jan. 11, 1972 [73] Assignee Adams Equipment Company, Incorporated St. Louis, Mo.

[54] MULTISTAGE SPRA YER 12 Claims, 7 Drawing Figs.

[5 2] US. Cl 239/428, 239/429, 239/434 [51] Int. Cl B05b 7/06 [50] Field of Search 239/433, 434, 429, 428

[56] References Cited UNITED STATES PATENTS 2,107,340 2/1938 Pedrick M 239/434X 2,813,750 11/1957 Marantz 239/434 X 2,931,580 4/1960 Johnson 239/434 X 3,070,317 12/1962 Hunter et 31.. 239/429 X 3,430,865 3/1969 McDougall... 239/434 X Primary Examiner-Lloyd L. King Attorney-Ralph W. Kalish ABSTRACT: A multistage sprayer utilized for cleaning, coating, and etching metals prior to painting adapted to serially clean the surface to be painted with a soap solution at a relatively high pressure, rinse the cleaned surface, coat the surface with a zinc phosphate-nitric acid solution at a relatively low pressure, rinse the phosphatized surface, and finally etch the surface with an acid solution for strengthening corrosion resistance. The sprayer incorporates a novel injector arrangement to obtain emission of a 20 percent zinc phosphate solution at a substantially relatively decreased line pressure for safe, effective phosphatizing.

Pmmmmnmz 3,633,829

SHEET 1 [IF 3 INVENTOR GEORGE R. ADAMS BY w.

ATTORNEY PATENTEU m1 1 1972 7 3I633Q829;

SHEET 2 0F 3 FIG.4 M 4/ 57 2 THERMIOSTATIC VALVE HIGH 7 PUMP INVENTOR GEORGE R. ADAMS BY w 'm ATTORN EY INVENTOR SHEET 3 UF 3 GEORGE R. ADAMS PATENIED JAN] 1 i572 mUmDOW ATTORNEY MULTISTAGE SPRAYER BACKGROUND OF THE INVENTION Heretofore, the methods employed in the preparation of metal for painting were unsatisfactory to the industry for many reasons. One method utilized a steam cleaning process wherein by means of pressurized air acid was entrained within the steam. This particular method was completely unsuitable as it caused the development of an uncomfortably hot and injurious environment. Moreover, in addition to making it difficult for one to see the spraying results, the steam mist carried acid particles which were inhaled by the operator. Another method involved a low-pressure spray process requiring an acid pump for mixing an iron phosphate solution with water before the coating step. This said method proved highly inaccurate for the purpose of controlling the concentration of the phosphatizing solution and rendered it, therefore, ineffective. Additionally, in the latter method, independentdiscrete units had to be utilized for effecting the cleaningpperation.

A still further cleaning process currently employed necessitated the use of relatively large dip tanks for the appropriate solutions with a crane or the like for transporting a metal body to be painted sequentially within the various tanks. The size of the dip tanks required the consumption of considerable plant space, and caused wastage of material.

It has been long recognized that zinc phosphate is the coating material of choice in industry. However, since it is waterinsoluble, there is the need to solubilitize same by use of nitric acid with the resulting solution being highly toxic and potentially hazardous, wherefore the use of same has been limited in the past. For proper and safe application, the zinc phosphatenitric acid solution must be sprayed at a low pressure. By the present invention, the unsatisfactory character of the methods heretofore known has been overcome, by the substitution of a portable, compact, unitary multistage sprayer by operation of which all the requisite stages may be efficiently accomplished, including the phosphatizing stage wherein a predetermined percentage of zinc phosphate-nitric acid solution is maintained and positively controlled.

SUMMARY OF THE INVENTION An object of the present invention is to provide a multistage sprayer which is portable in construction, and compact in size for ready mobility and installation within a minimum of space.

Another object of the present invention is to provide a multistage sprayer which effectively and efficiently prepares a metal surface for painting by unitarily incorporating means for effecting the cleaning, rinsing, coating and etching steps thereby eliminating the need to utilize a multiplicity of apparatuses and devices.

A further object of the present invention is to provide a multistage sprayer incorporating a spray wand having a pair of nozzles connected in parallel so that one or both may be opened for increasing or reducing the pressure of the spray emitted therefrom.

Another object of the present invention is to provide a multistage sprayer which may be adapted for operation by a gasoline engine so that said machine may be mounted on a vehicle for field usage.

A still further object of the present invention is to provide a multistage sprayer of the type described wherein a multiplicity of diverse concentrated solutions may be serially injected within a single spray line for ultimate discharge from the sprayer.

Another object of the present invention is to provide a multistage sprayer which considerably reduces the time heretofore required for completing a metal cleaning process by embodying all the requisite stages in one system capable of being executed by a single operator.

A further object of the present invention is to provide a multistage sprayer wherein the various stages of preparation of a metal surface for painting may be accomplished fully, automatically through a pushbutton switch conveniently located on the spray wand.

A still further object of the present invention is to provide a multistage sprayer of the type .described which is adapted to effectively and reliably reduce the line pressure to a desired level at various stages of operation and which injects concentrated solutions of predetermined, positively controlled strength within the spray line.

Another object of the present invention is to provide a multistage sprayer of the type described which is completely safe in operation; which is capable of being operated by relatively unskilled personnel; which can be economically manufactured; and which may be adapted to prepare a multiplicity of metal articles for painting such as appliances, automobile or truck bodies, mobile homes, signs, and many others.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a multistage sprayer constructed in accordance with and embodying the present invention.

FIG. 2 is a rear view with the rear panel being removed.

FIG. 3 is a front view with a portion being cut away.

FIG. 4 is an enlarged fragmentary view illustrating the spray nozzle of the present invention.

FIG. 5 is a transverse sectional view takenon the line 55 of FIG. 3.

FIG. 6 is a flow diagram of the hydraulic system within the sprayer.

FIG. 7 is a diagram of the electrical circuitry of the sprayer.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now by reference characters to the drawings which illustrate the preferred embodiment of the present invention, A generally designates a multistage sprayer comprising a cabinet 1 having a front wall 2, rear wall 3, and top wall 4 and parallel sidewalls 5, 6', respectively. Front wall 2 includes: a lower portion 7, which extends vertically substantially half the height of cabinet 1; an upper portion 8, which is disposed planarwise inwardly of lower portion 7 and an intermediate portion constituted of a removable panel 9. Said panel 9 is provided on its front and side margins with a skirt 13, the inner face of which is presented against the adjacent edges of lower front wall portion 7 and sidewalls 5 and 6. Additionally, panel 9 is provided with a lock 14 for assuring against inadvertent or unauthorized removal.

Upper front wall portion 8 comprises a control panel c on which is provided a pressure gauge 10, a temperature gauge 1 1, and a plurality of cycle indicator lamps, as at 12.

Fixed within cabinet 1 is a mounting frame 15 comprising a base 16 and vertically extending

rear uprights

17, 17" and

front uprights

18, 18 which latter are of less height than the former and correspond to the heights of lower front wall portion 7. The upper portion of said

uprights

17, 17 and l8, 18 support a diagonally disposed latticed deck 19 onto which is secured a mounting plate 20, the latter being substantially parallel with removable panel 9 being viewable upon removal of said panel 9.

Mounted on base 16 is a pump P having a drive shaft (not shown) on which is mounted a pulley 21 around which is trained an endless belt 22, engaged also upon a pulley (not shown) keyed on the shaft (not shown) of a motor M mounted on base 16 in spaced relationship to pump P. Pump P is of the high-pressure type, capable of developing pressures in excess of 600 p.s.i. Because of the relatively high pressure of Pump P, the latter incorporates a safety bypass line p (FIG. 6). Experiments have shown that the optimum pressure at which pump P should operate in the present invention is approximately 500 p.s.i., as will be described herein below.

Connected to the intake side, as by a dual fitting 23 of pump P, is one end of a soap line 24 and of a waterline 25. Soap line 24 extends upwardly from pump for connection at its other end by fitting 26, to a conventional soap injector 27. Said latter is integrally formed with a fitting 28 disposed nonnal to the path of flow therethrough connected to one end of a conduit 29 passing through an opening 30 in rear wall 3 for communication with a remote source (not shown) of a suitable soap or detergent base cleaning solution. Injector 27 is threadedly engaged to an elbow 31 having a pressure gauge 3 mounted thereon so that the pressure within soap line 24 may be readily observed at all times. Elbow 31 is connected to a riser which at its other end is secured to a tee-fitting 33, one outlet at which is connected to a temperature control valve 34, and the opposed outlet to a solenoid valve 35. Disposed within riser 32 upwardly of tee-fitting 33 is a solenoid valve 36 which is in normally closed condition as will be further described hereinbelow, and in circuit through lead 37 to a circuit control box C, the latter being secured by appropriate bracing (not shown) to the deck 19. Solenoid 35 is connected to waterline 25 and is in circuit with control box C by conductor 38.

Said temperature control valve 34 is provided with diametrically opposed

openings

39, 39; opening 39 being threadedly engaged to a hot water pipe 41, and the opening 39 to a cold water pipe 42. The valve 34 incorporates a built-in thermostat (not shown) for regulating the temperature of the water therein, which thermostat is in circuit through lead 40 with temperature gauge 11. Thus, in normal operation, hot and cold water fiow through pipes 41, 42, respectively into valve 34 wherein the water is mixed so that the discharge is maintained at a controlled constant temperature. In the present invention the optimum temperature is 140,

The discharge side of pump P is connected through a conduit 43 with fitting 44 fixed within mounting plate (FIG. 3). Fitting 44 is connected to a water conduit 45 which is mounted on plate 20 and extends upwardly of said plate 20 where same is provided with a solenoid valve 46 in circuit with control box C by conductor 47. Conduit 45 extends transversely of plate 20 and thence downwardly for connection to a discharge fitting 48; there being a check valve 49 located within said conduit 45 intermediate solenoid valve 46 and discharge fitting 48 for precluding any backflow of fluid through the line. Discharge fitting 48 is connected to one end of a hose 50 which passes through an opening 51 in sidewall 6, the other end being connected to a pistol grip handle 52 of a spray wand 53. Also connected to handle 52 is a lead 54, one end being in circuit with a pushbutton switch 55 located on the rear portion of pistol grip 52, the other end being in circuit with the low voltage side of a transformer T mounted on plate 20; said transformer T is in circuit by leads 56 to circuit control box C.

Transformer T is designed for reducing the voltage to 12 volts for safety to the operator in handling said spray wand 53. Wand 53 generally comprises an elongate tube 57 having at its outer end a dual nozzle attachment 58; the latter incorporating a pair of axially, parallel spaced-apart

nozzles

59, 59 which are attached to the tube 57 through a tee-fitting 60. Each

nozzle

59, 59 is provided with a manually operated shutoff valve 61, 16, respectively so that either one or both of said

nozzles

59, 59, respectively may be closed independently of the other. It will be noted that when one valve 61 or 61' is closed the other will be emitting a spray at a higher pressure than would be the case if both

nozzles

59, 59 were in operation. Experiments have shown that with only one spray nozzle 59 in operation, the fluid will be discharged at substantially the pump pressure, which is, preferably, 500 psi. However, when the second nozzle 59' is opened by valve 61' the combined pressure of both

nozzles

59, 59, is reduced to approximately 170 p.s.i.

Branching from conduit 45 is a pair of

lines

62, 63, extending transversely across plate 20 and connected at their respective ends to the opposed vertical portions of conduit 45. Line 62 incorporates a normally closed solenoid valve 64, and an injector 65 downstream of valve 64. Injector 64 is provided with fitting 66, normal to the axis of line 62, for connection to one end of a conduit 67 which passes through an opening 68 within rear wall 3; the other end communicating with a remote source (not shown) of acid solution for etching purposes. Intermediate injector 65 and conduit 45 line 62 is provided with a check valve 69 for preventing backflow of any fluid therethrough.

Line 63 incorporates a solenoid valve 70 which is normally closed, but when opened permits passage of water from conduit 45 through line 63. Provided in tandem within line 63 are a pair of

injectors

71, 71, each having fitting 72, 72', respectively, normal disposed to the path of flow therethrough. Connected to respective fitting 72, 72' is a

line

73, 73 each of which passes through appropriate openings 74, 74' within rear wall 3 for placement within a container (not shown) filled with a zinc phosphate-nitric acid solution. Zinc phosphate is a powder which is soluble in a few liquids, such as acids, making same dangerous in usage.

Injectors

71, 71" are identical in construction, although having different relative dimensions, with injector 71' being proportionately larger than injector 71 in the range of l.33:l to 2:1. The structural portions of injector 71 corresponding to those in injector 71 will be given like numerals for facilitating understanding and obviating unnecessary repetitive explanation. Referring to FIG. 5 injector 71 comprises a body 75 having a bore 76 therethrough, which bore 76 is counterbored at 77 for defining a chamber 78. Bore 76 is counterbored a second time, as at 79 for developing a shoulder 80 against which abuts the peripheral flange 81 of a nozzle bushing 82. Nozzle bushing 82 is provided with an axial passage 83 of decreasing cross section merging from flange 81 into a relatively small orifice 84 through which the fluid passing through line 63 is forced into chamber 78 in the form of a jet stream. Extending from chamber 78 and within the path of fluid travel is a diffuser chamber 85 which is in communication at its inner end with chamber 78 and tapers divergingly diametrically outwardly where same is threadedly engaged to a relatively small connector conduit 63a. It will be observed that the inner diameter of connector pipe 63a is relatively larger than that of conduit 63.

Body 75 is provided with a cylindrical boss 86 having external threads 87 for engaging the internal threads 88 of said fitting 72, the latter having an axial bore 89 of relatively small diameter extending therethrough. Fitting 72 incorporates a head portion 90 and a stern portion 91 of reduced cross section for being received within said line 73 with its end face abutting against the shoulder 900. Bore 89 of fitting 72 communicates with chamber 78 through a passage 92 axially aligned with bore 89. Passage 92 is counterbored as at 93 for housing a ball valve 94 which normally is urged into seating engagement with bore 89 by means of spring 95; one end of spring 95 engaging ball 94 and the other end bearing against the shoulder 96. Ball valve 94 yields under the pressure of the liquid coming through bore 89 as will be presently described.

Fitting 72 is provided with an internally threaded opening 97 being axially normal to bore 89 and in communication therewith. Received within opening 97 are the external threads 98 of a setscrew 99 which may be adjusted rotatingly for projection within bore 89 to limit the cross-sectional area thereof thereby controlling the rate of flow through bore 89. The flow of liquid through

injectors

71, 71 creates a suction for drawing the zinc phosphate-nitric acid solution within chamber 78 for entraining a predetermined volume within the motive liquid for propulsion through the respective diffuser chambers 85, 85'. The volume of solution drawn into chamber 78 is controlled by setscrew 99 and the bias of ball valve 94. Under normal conditions it is preferred to adjust setscrew 99 so that the solution drawn within chamber 78 is combined with the motive liquid in a ratio of 90: 10; i.e., 90 percent water and 10 percent zinc phosphate solution. Since there are two

injectors

71, 71 connected in tandem, the water-zinc phosphate ratio entering the conduit 45 will be approximately 80 percent water and 20 zinc phosphate solution.

Line 63 also incorporates a check valve v for precluding any backflow of fluid therethrough.

Referring to the control panel 0 on front wall upper portion 8, it has been heretofore stated that temperature gauge 11 is connected through lead 40 to the temperature control mixing valve 34. Additionally, the pressure-indicating gauge is connected through lead 100 to a flowmeter (not shown) conveniently connected to conduit 43 intermediate the discharge side of pump P and the fitting 44. Each of the indicating lamps 12 are connected through wires collectively designated w (FIG. 2) to the control box C and will be further described in detail hereinbelow. Circuit control box C is connected by ower leads, collectively designated 1, which pass through sidewall 6 for connection to a power box B. Said power box B includes a circuit breaker switch 105 and a master switch 1 18; there being power lines, collectively designated L, connecting the circuit breaker 105 master switch 1 18 to a source of power 101 (FIG. 7).

Referring to FIG. 6 of the drawings, the 6-stage operation will be briefly described with the circuitry being eliminated for a more comprehensive discussion later. In operation, cold water and hot water enter temperature control valve 34 through pipes 41, 42 respectively; said valve 34 mixing the water and maintaining same at a constant temperature for discharge. As noted hereinabove the optimum temperature is maintained at desirably 140. 1n the first stage, water solenoid valve 35 is closed and soap solenoid 36 is opened so that the water being pumped from valve 34 is directed through riser 32 and injector 27 for receiving by suction a predetermined amount of soap solution through conduit 29 for ultimate delivery through line 34 to the intake side of pump P. Pump P forces the soap solution through

conduits

43, 45, and through solenoid 46 which is energized, being in opened position; the

solenoid valves

64, 70 being closed, for permitting thesoap solution to pass through check valve 49 and conduit fitting 48 into hose 50 for discharge through nozzle 59. It will be observed that in the first stage, the nozzle 59' may be closed by valve 61 for achieving maximum pressure in spraying the soap solution upon the object to be treated.

in the second stage, the soap solenoid 36 is deenergized and thereby closed while the water solenoid 35 is deenergized thereby opened for effecting flow of water from temperature control valve 34 through lines 25 to the intake side of pump P. Said pump forces the liquid through the

conduits

43, 45 for ultimate delivery to the hose 50 and emission through nozzle 59. It will be observed that in both the first and second stages, the valve 61 is closed for maintaining maximum pressure for cleaning and rinsing which are effected in these stages.

After completion of the rinsing or second stage, control valve 61' of nozzle 59 is opened so that the remaining stages will be at a lower pressure than the first two stages. The pressure of the spray being emitted through both

nozzles

59, 59 is approximately one-third of or 66.7 percent lower than the pressure of the emitted spray when only nozzle 59 is utilized. Therefore, if the initial pressure of the spray is 500 p.s.i., the pressure after valve 61 is opened will be reduced two-thirds or approximately to 170 p.s.i.

The third stage comprises coating or phosphatizing the metal for resisting corrosion and enhancing paint adhesion. Solenoids 46 and 64 are closed and solenoid 70 is opened for directing the water through line 63 and nozzle passage 83 of injector 71 for increasing the velocity of the water traveling therethrough, which is accompanied by jetting the water through orifice 74 into chamber 78 thereby reducing the pressure therein nd creating suction for drawing into chamber 78 the zinc phosphate-nitric acid solution. The volume of the solution is controlled by setscrew 99 and the bias check valve 94, as above described. The zinc phosphate solution is entrained within the motive liquid for propulsion through diffuser 85 into the connector conduit 63a. It is well known in the art that by forcing a liquid through an area of decreasing cross section, the velocity thereof is increased with a pressure decrease, causing an energy loss which is a function of the ratio between the diameters of the venturi orifice 84 and pipe 63 and is referred to as the ratio of permanent pressure loss. Because of this energy loss, the pressure of the fluid entering connector pipe 63a will be less than the pressure of the liquid within conduit 63. In the preferred embodiment of the present invention, the pressure of the water-zinc phosphate solution entering connector pipe 63a is approximately two-thirds of the pressure of the water entering conduit 63. Thus, the pressure of the water-zinc phosphate solution into connector pipe 63a would be approximately 330 p.s.i. if the initial pressure was 500 p.s.i.

Under optimum conditions, setscrew 99 is adjusted within fitting so that the zinc phosphate solution is drawn within chamber 78 for mixing with the motive liquid in a ratio of 90:10; i.e., 90 percent water and 10 percent zinc phosphate solution.

The water-phosphate solution is then passed through nozzle passage 73" of injector 71' which as above described is proportionately dimentially larger than injector 71 in the range of 1.33:1 to 2:1. Said solution is jetted through orifice 84' into chamber 78 for further reducing the pressure and increasing the velocity thereof. The zinc phosphate solution is drawn within chamber 78' in the same manner as hereinabove described for injector 71 and is entrained in the same 90:10 relationship directed through diffuser 85 into conduit 63b. Therefore, the water-phosphate mixture entering conduit 45 from discharge conduit 63b is approximately 80 percent water and 20 percent phosphate. Additionally, the pressure is reduced another two-thirds so that the pressure is approximately 44 percent or four-ninths the original pressure within conduit 63, or approximately 220 p.s.i. Thus, the dangers heretofore realized by the entrainment of zinc phosphate solution in water are substantially eliminated.

in the

fourth stage solenoids

64 and 70 are closed and solenoid 46 is opened so that the water is passed through

lines

45 and 50 for rinsing the phosphatized item being sprayed.

In the

fifth stage solenoids

46 and 70 are closed and solenoid 64 is opened whereupon the fluid will flow into line 62 for injecting the acid solution into line 45 for discharge through check valve 69 to line 45. The acid solution is passed through conduit 50, tubular portion 57, and outwardly of

nozzles

59, 59. The acid spray strengthens corrosion resistance and leaves all metal surfaces in optimum painting condition. After completion of the

fifth stage solenoid

64 and 70 are closed and solenoid valve 46 is opened for the sixth and last stage, a rinse stage, wherein water will pass through solenoid 46,

line

45 and 50 for discharge through nozzles 59, 59'. If additional pressure is desired the control valve 61 may be closed so that the water will be ejected through nozzle 59 at an increased pressure. The sixth stage may be terminated by pushing the button 55 thereby closing all

solenoid valves

46, 64 and 70 for shutting any fluid supply to the spray wand 52.

The circuitry of the present invention is illustrated in FIG. 7 wherein 101 designates a source of power having

power lines

102, 103 and 104 extending therefrom for circuitwise connection to the power box B of sprayer

A. Power lines

102 and 103 are connected to one side of a circuit breaker switch 105 conveniently mounted on sidewall 6 of cabinet 1. The other side of circuit breaker switch 105 is adapted to engage contacts 106, 107 for supplying current through

conductors

108, 109, respectively to one side of a normally opened

switches

110, 111. Said latter are closed by the energiz ation of a relay r as will be further described hereinbelow, and are adapted to engage

contacts

112, 113, respectively of

conductors

114, 115, respectively; both

conductors

114, 1 15 passing through a conventional overload circuit 116 for connection to said motor M. Power line 104 is connected to a common lead 117 through master switch 1 18.

Connected to conductor 108, at junction 119, there is a conductor 120 which in turn is connected to one side of a power-on lamp 121, the other side being connected by lead 122 to the common lead 1 17 for completing a circuit through master switch 118 to source of power 101. Thus, when circuit breaker switch 105 and master switch 118 are in circuit closed condition power-on lamp 121 will be illuminated to indicate to the user that sprayer A is conditioned for usage.

Connected to conductor 109 at junction 123 is a lead 124 for transmitting current through branch leads 125, 126, 127,

and 128. Branch lead 127 is connected to one side of a normally closed switch s, the other side being connected by conductor 129 to one side of a normally closed switch 130, the other side of which is connected by lead 131 to a stepper switch arm 132. The movement of said stepper switch arm 132 is controlled by an advance relay 133 and a reset relay 134 provided with a conventional stepping relay circuit S. Stepper switch arm 132 is adapted to sequentially engage a plurality of

contacts

135, 136, 137, 138, 139, 140, 141 and 142 responsive to the selected energization of advance relay 133, as will be described presently. One side of advance relay 133 and reset relay 134 is connected by

conductors

143, 144, respectively, to one side of a normally open switch 145, 146, respectively; the other side of each switch 145, 146 being connected to

branch lead

126 and 128, respectively. The other side of each

relay

133, 134 is connected to conductor 147 which is in circuit with common lead 117.

Branch lead 125 is connected to one end of the high-voltage side of a transformer T, the other end of the high-voltage side being connected by a conductor 148 to common lead 117 for completing the circuit therethrough. The low-voltage side of transformer T is connected by conductor 149 to contact 150 and by conductor 151 to one side of a relay 152, which latter controls said switches 145 and 130. The other side of relay 152 is connected by conductor 153 to one side of a normally closed switch 154, the other side being connected by lead 155 to a contact 156. Said contacts 150 and 156 are positioned in adjacent relationship for engagement by the pushbutton switch 55 of the spray wand 53. Switch 154 is controlled by a relay 157 and positioned adjacent thereto, said relay 157 being connected by

leads

158, 158 to common lead 117 and conductor 159, respectively. Said conductor 159 has one end engaged with said stepper switch contact 142 and the other end connected to one side of a relay 160, the other side of which is connected to common lead 117. It will be observed that relay 160 controls switches s and 146, for purposes to be later described.

The contacts 135-142 of stepping relay S are all in circuit with common lead 117, as will now be described. Contact 135 is connected by conductor 161 to one side of a start cycle lamp 162, the other side being connected by lead 163 to common lead 117.

Contact 136 is connected by conductor 164 to normally closed switch arm 165, which engages a contact 166 for completing a circuit through a lead 167 to one side of a relay 168, the other side of same being connected by a conductor 169 to the common lead 117. Said relay 168

controls switches

165, 170, 171, and 172, the latter being connected by a conductor 173 to the conductor 164 along with said switch arm 165. Switch 170 is connected by conductor 174 to said contact 166, which as above described, is in circuit through lead 167 to the relay 168. Switch 170 is adapted to engage contact 175 which is connected by conductor 176 to a lead 177; one end of the latter being connected to a contact 178, the other end to said relay r. The other side of relay r is connected by conductor 179 through the overload circuit 116 to common lead 117. Switch arm 171 is adapted to engage said contact 178 and is connected by conductor 180 to said conductor 129 for completing a circuit through switch s branch lead 127 and lead 124. Switch 172 is adapted to engage contact 181 which is connected by conductor 182 to one side of a relay 183, the other side being connected by lead 184 to common lead 117. Also connected to conductor 182 at junction 185 is a branch lead 186 which is connected to one side of said water solenoid 35 the other side being connected by conductor 187 to the common lead 117. Water solenoid 35 is normally opened for waterflow therethrough so that upon energization the same will close thereby precluding flow therethrough. Connected to branch lead 186 are conductors 188, 189 which are respectively, connected to one side of said soap solenoid 36 and a soap" lamp 190, the other side of each being connected by

conductors

191, 192, respectively, to conductor 187. As above described, said

solenoids

35 and 36 are adapted to be alternatively opened and closed so that when soap solenoid 36 is open, water solenoid 35 will be closed, and vice versa.

Contact 137 is in circuit by conductor 193 to one side of a switch 194 adapted to engage a contact 195 which is attached by lead 196 at junction 197 to said conductor 182. Connected to conductor 193 at junction 198 is a conductor 199 which in turn is in circuit with said stepper switch contacts 139 and 141 through

leads

200 and 201, respectively. Also connected to conductor 199 at junction 202 is a conductor 203 which latter is connected to one side of said solenoid 46, the other side of same being connected by lead 204 to common lead 117. Connected to conductor 203 at junction 205 is one side of a normally closed switch 206 the other side of which is connected by conductor 207 to one side of a rinse" lamp 208 having its other side connected by lead 209 to lead 204. It will be observed that switch 206 and switch 194 are controlled by relay 183 for purposes to be further described in the operation hereinbelow.

Contact 138 is in circuit through lead 210 to one side of said "phosphate" solenoid 70, the other side being connected by conductor 211 to common lead 117. Connected in parallel with phosphate solenoid 70 is a "phosphate lamp 212, one side being connected by a conductor 213 to lead 210 and the other side being connected by lead 214 to conductor 211.

Contact 140 is connected by lead 215 to one side of said acid solenoid 64, the other side being connected to common lead 117 by conductor 216. Connected in parallel with solenoid 64 is an acid" lamp 217; one side of which is in circuit through lead 218 to lead 215 and the other side by conductor 219 to conductor 216.

With circuit breaker switch engaging contacts 106, 107, respectively, current will flow through

conductors

108 and 109 to the normally opened switch arms 1 10, 111 for conditioning same for ultimate energization of motor M. Moreover, current will flow through conductor to one side of power-on lamp 121 and when master switch 118 is closed, the lamp 121 will be illuminated by completion of the circuit through common lead 117. Current is also directed through conductor 109, lead 124, branch lead 127, switch 3, conductor 129, switch 130, lead 131 to stepper switch arm 132. In initial position, the stepper switch arm 132 engages contact for sending current through conductor 161 for illuminating the start-cycle" lamp 162. With both

lamps

161 and 162 illuminated, the sprayer A is ready for operation. The operator engages pushbutton 55 of the spray wand 53 to engage contacts 150, 156 thereby closing a circuit to the lowvoltage side of transformer T for energizing relay 152. Upon energization of relay 152 switch 130 will open, thereby terminating current flow to stepper switch arm 132, and switch will close, thereby energizing advance relay 133 by closing a circuit through conductor 143, switch 145, branch lead 126, and lead 124. When advance relay 133 is energized stepper switch arm 132 will be advanced for engagement with the next sequential contact, in this case contact 136. As soon as the operator releases pushbutton switch 55, the relay 152 is deenergized for opening switch 145, thereby deenergizing advance relay 133, and closing switch 130, thereby once again sending current to stepper switch arm 132. Each time the operator engages pushbutton 55, relay 152 is energized for closing a circuit to said advance relay 33, and opening the circuit to stepper switch arm 132. Therefore, in subsequent discussion this explanation may be avoided.

When contact 136 is engaged current will flow through conductor 164, switch and lead 167 for energizing relay 168 whereupon normally closed switch 165 will open and normally opened

switches

170, 171 and 172 will close into engagement with their respective contacts 175, 178 and 181. Upon closing of switch 171, a circuit is closed through

conductors

177, 180, 129, switch s, branch lead 127 and lead 124 to energize relay r whereupon said hot" switches 110 and 111 are closed for energizing motor M. Simultaneously, a circuit is closed through

conductors

177, 176, switch 170,

conductors

174 and 167 for sealing in relay 168. Therefore, so long as switch 171 is closed, the switch 170 will also be closed for maintaining relay 168 in energized condition. The closing of switch 172 completes a circuit from stepper switch am 132,

conductors

164, 173, switch 172 and conductor 182 for energizing relay 183. Responsive to relay 183 being energized, switch 206 is opened and switch 194 is closed into engagement with contact 195 for completing a circuit through

conductors

132, 196, 199, 203 and 204 thereby energizing water solenoid 46 for waterflow therethrough. Simultaneously therewith, a circuit is completed through

conductors

182, 186, 188, 191, 187 for opening said soap solenoid 36 and through

conductors

182, 186, 189, 192 and 187 for illuminating soap" lamp 190. It will be observed that the rinse" lamp 208 will not be illuminated because switch 206 is in opened condition. The soap solution is sprayed through wand nozzle 59 until the operator again pushes button 55 which effects advancement of stepper switch arm 132 for engagement with contact 137. When stepper switch arm 132 is disengaged with contact 136, the circuit is broken through

conductors

164, 173 switch 172 and conductor 182 for deenergizing relay 183, thereby opening switch 194 and closing switch 206.

Upon engagement with contact 137 a circuit is closed for sending current through

conductors

193, 199, 203 and 204 for illuminating "rinse" lamp 208 through switch 206, and

conductors

207, 209, and 204. The water solenoid 46 and the rinse lamp 208 will remain energized until the operator again presses pushbutton 55 for advancing stepper switch arm 132 for engagement with contact 138 whereupon a circuit is closed through leads 210 and 211 for opening phosphate solenoid 70 and for illuminating phosphate lamp 212 through conductors 213 and 214. The third step or phosphate stage of the cycle is terminated upon the operator engaging pushbutton 55 to advance stepper switch arm 132 for engagement to contact 139 for initiating the fourth stage. Water solenoid 46 and rinse lamp 208 are energized, as above described for step 2 when switch arm 132 was engaged to contact 137, by closure of a circuit through

conductors

199, 203 and 204.

The fifth stage of acid spray stage is commenced when the operator pushes button 55 to advance the stepper switch arm 132 for engagement with contact 140. A circuit is closed through

leads

215 and 216 for energizing acid solenoid 64 and illuminating acid" lamp 260 through

conductors

218 and 219 thereby effecting the flow of acid to the spray wand as above described.

When stepper switch arm 132 is advanced into engagement with contact 141, the circuit is closed for sending current through

conductors

199, 203, 204 for energizing water solenoid 46 and illuminating rinse lamp 208, as above described for the second and fourth stages when stepper switch arm 132 was in engagement with

contact

137 and 139, respectively.

After the sixth and final stage, the operator engages contact 55 for advancing stepper switch arm 132 for engagement with contact 142 thereby closing the circuit through conductors 159 and common lead 1 17 for energizing relay 160.

A circuit is also closed through

conductor

159, 158 and 158 to common lead 117 for energizing relay 157 whereupon switch 154 located in the low-voltage circuit of transformer T willbe opened preventing energization of relay 152 and hence advance relay 133 until stepper switch arm 132 is reset to its initial position.

When relay 160 is energized, switch 146 is closed and switch s is opened. Upon closing of switch 146 a circuit is closed through conductor 144 branch lead 128 and conductor 124 for energizing reset relay 134 whereupon stepper switch arm 132 is returned or reset into engagement with contact 135. Upon opening of switch s, the circuit is broken for terminatin g current flow to stepper switch arm 132 and terminating current flow through conductor 180 switch 171, lead 177 for deenergizing relay r whereupon switches 110 and 111 will be opened for effecting deencrgization of motor M. Additionally, the circuit to relay 168 through

conductors

167, 174, switch 170, conductor 176 will be opened for deenergizing same. When stepper switch arm 132 disengages contact 142,

the relay will be deenergized for accordingly closing switch s and opening switch 146, thus completing the full cycle of multistage sprayer A and placing same in condition for commencement of the spray cycle a second time.

Although the

particular solenoidvalves

35, 36, 46, 64 and 70 have been described hereinabove in their peculiar relationships, it will be understood that a single selector valve may be located between thermostatic valve 34 and pump P for accomplishing the same results as

solenoid valves

35 and 36. Likewise, a single three-way selector valve may be located at the junction of

lines

43, 62 and 63 instead of

solenoid valves

46, 64 and 70.

Having thus described my invention, what I claim and desire to obtain Letters Patent for is:

1. A sprayer for preparing metal for painting comprising:

a source of motive liquid;

a pump having an intake side and a discharge side;

first and second conduit means connecting said motive liquid source to the intake side of said pump;

first valve means located between said motive liquid source and said pump for selectively directing said liquid through said first or second conduit means;

a source of cleaning solution;

third conduit means connecting said source of cleaning solution with said second conduit means between said pump and said source of motive liquid, for entrainment therein;

a spray nozzle;

fourth, fifth, and sixth conduit means located between and connecting said spray noule and the discharge side of said pump;

second valve means located between said pump and said fourth, fifth, and sixth conduit means for selectively directing said liquid discharge by said pump therethrough;

a source of coating agent;

seventh conduit means connecting said source of coating agent to said fifth conduit means between said second valve means and s aid spray nozzle;

a source of acid solution;

eighth conduit means connecting said source of acid solution with said sixth conduit means between said second valve means and said spray nozzle;

circuit means electrically connecting said first and second valve means, and control means for effecting operation of said circuit means for causing continuous flow of said motive fluid and for automatically serially entraining therein said cleaning solution, coating agent and acid solution for discharge through said spray nozzle.

2. A sprayer for preparing metal for painting as defined in claim 1 and further characterized by said first and second valve means being solenoid valves.

3. A sprayer for preparing metal for painting as defined in claim 1 and further characterized by said first valve means comprising solenoid valves located within each of said first and second conduits, and said second valve means comprising individual solenoid valves located within said fourth, fifth, and sixth conduit means.

4. A sprayer for preparing metal for painting as defined in claim 2 and further characterized by said pump being of the high-pressure type and wherein said control means are provided upon said spray nozzle.

5. A sprayer for preparing metal for painting as defined in claim 1 and further characterized by first injector means provided at the juncture of connection between said second and third conduit means; second injector means provided at the juncture of said fifth and seventh conduit means; and third injector means provided at the juncture of said sixth and eighth conduit means.

6. A sprayer for preparing metal for painting as defined in claim 1 and further characterized by said spray nozzle having first and second discharge outlets; a valve provided within each of said first and second outlets to selectively permit sinliil gle or joint discharge through said outlets for controlling pressure of the emitted spray.

7. A sprayer for preparing metal for painting as defined in claim 2 and further characterized by said circuit means, including a stepping switch having a wiper arm and at least seven positions for serial contact by said wiper arm wherein:

in said first position, said first and second valve means are energized for opening said second and fourth conduit means for effecting transmission of said cleaning solution through said third conduit means and fourth conduit means for emission through said spray nozzle;

in the second position, said first and second valve means are energized for opening said first and fourth conduit means for directing water to said spray nozzle in a rinsing operation; in the third position, said first and second valve means are energized for opening said first and fifth conduit means for transmitting said coating agent through said seventh conduit means and said fifth conduit means for emission through said spray nozzle; in the fourth position, said first and second valve means are energized to open said first and fourth conduit means for directing water to said spray nozzle in a rinsing operation;

in the fifth position, said first and second valve means are energized to open said first and sixth conduit means for transmitting acid through said eighth conduit means and sixth conduit means for emission through said spray nozzle;

in the sixth position, said first and second valve means are energized to open said first and fourth conduit means for directing water through said spray nozzle in a rinsing operation; and

in the seventh position, said first and second valve means are deenergized for closing all said conduits.

8. In a sprayer for preparing metal for painting, an injector assembly for entraining an acid solution at a relatively high concentration within a motive liquid comprising:

a source of motive liquid under pressure;

a source of acid solution;

a first injector having an axial bore with an intake end and a discharge end;

a second injector unit having an axial bore with an intake end and a discharge end; means connecting the discharge end of said first injector to the intake end of said second injector;

first conduit means connecting said source of motive liquid to said first injector intake end;

second conduit means connected to said second injector discharge and and constituting a discharge conduit;

there being a passage within each injector unit normal to said axial bore and in communication therewith;

said second injector unit having dimensions proportionally larger than the dimensions of said first injector unit;

separate conduit means connecting said source of acid solution to each passage of each injector unit.

9. The invention as described in claim 8 and further characterized:

there being a chamber within each injector bore;

said passage of each first and second injector units communicating said chamber with said third conduit means;

a nozzle incorporated within each bore of said first and second injector units connecting the related intake end with each chamber;

a diffuser formed within each bore connecting each chamber with the discharge end of said first and second injector units; whereby as said liquid is directed through the nozzle of said first and second injector units the pressure is reduced for drawing said acid solution from said source through said separate conduit means into said chamber and outwardly of each of said diffusers for entraining said solution within the motive liquid.

10. The invention as defined in claim 9 and characterized by said first and second injector units being positioned in axially aligned relationship.

l. The invention as defined In claim 10 and further characterized by said first and second injector units having proportionally different relative dimensions.

12. The invention as defined in claim 11 and further characterized by said second injector unit having dimensions proportionally larger than the respective dimensions of said first injector unit in the range of 1 33:1 to 2: 1.

Claims

1. A sprayer for preparing metal for painting comprising: a source of motive liquid; a pump having an intake side and a discharge side; first and second conduit means connecting said motive liquid source to the intake side of said pump; first valve means located between said motive liquid source and said pump for selectively directing said liquid through said first or second conduit means; a source of cleaning solution; third conduit means connecting said source of cleaning solution with said second conduit means between said pump and said source of motive liquid, for entrainment therein; a spray nozzle; fourth, fifth, and sixth conduit means located between and connecting said spray nozzle and the discharge side of said pump; second valve means located between said pump and said fourth, fifth, and sixth conduit means for selectively directing said liquid discharge by said pump therethrough; a source of coating agent; seventh conduit means connecting said source of coating agent to said fifth conduit means between said second valve means and s aid spray nozzle; a source of acid solution; eighth conduit means connecting said source of acid solution with said sixth conduit means between said second valve means and said spray nozzle; circuit means electrically connecting said first and second valve means, and control means for effecting operation of said circuit means for causing continuous flow of said motive fluid and for automatically serially entraining therein said cleaning solution, coating agent and acid solution for discharge through said spray nozzle.

6. A sprayer for preparing metal for painting as defined in claim 1 and further characterized by said spray nozzle having first and second discharge outlets; a valve provided within each of said first and second outlets to selectively permit single or joint discharge through said outlets for controlling pressure of the emitted spray.

7. A sprayer for preparing metal for painting as defined in claim 2 and further characterized by said circuit means, including a stepping switch having a wiper arm and at least seven positions for serial contAct by said wiper arm wherein: in said first position, said first and second valve means are energized for opening said second and fourth conduit means for effecting transmission of said cleaning solution through said third conduit means and fourth conduit means for emission through said spray nozzle; in the second position, said first and second valve means are energized for opening said first and fourth conduit means for directing water to said spray nozzle in a rinsing operation; in the third position, said first and second valve means are energized for opening said first and fifth conduit means for transmitting said coating agent through said seventh conduit means and said fifth conduit means for emission through said spray nozzle; in the fourth position, said first and second valve means are energized to open said first and fourth conduit means for directing water to said spray nozzle in a rinsing operation; in the fifth position, said first and second valve means are energized to open said first and sixth conduit means for transmitting acid through said eighth conduit means and sixth conduit means for emission through said spray nozzle; in the sixth position, said first and second valve means are energized to open said first and fourth conduit means for directing water through said spray nozzle in a rinsing operation; and in the seventh position, said first and second valve means are deenergized for closing all said conduits.

8. In a sprayer for preparing metal for painting, an injector assembly for entraining an acid solution at a relatively high concentration within a motive liquid comprising: a source of motive liquid under pressure; a source of acid solution; a first injector having an axial bore with an intake end and a discharge end; a second injector unit having an axial bore with an intake end and a discharge end; means connecting the discharge end of said first injector to the intake end of said second injector; first conduit means connecting said source of motive liquid to said first injector intake end; second conduit means connected to said second injector discharge end and constituting a discharge conduit; there being a passage within each injector unit normal to said axial bore and in communication therewith; said second injector unit having dimensions proportionally larger than the dimensions of said first injector unit; separate conduit means connecting said source of acid solution to each passage of each injector unit.

9. The invention as described in claim 8 and further characterized: there being a chamber within each injector bore; said passage of each first and second injector units communicating said chamber with said third conduit means; a nozzle incorporated within each bore of said first and second injector units connecting the related intake end with each chamber; a diffuser formed within each bore connecting each chamber with the discharge end of said first and second injector units; whereby as said liquid is directed through the nozzle of said first and second injector units the pressure is reduced for drawing said acid solution from said source through said separate conduit means into said chamber and outwardly of each of said diffusers for entraining said solution within the motive liquid.

11. The invention as defined in claim 10 and further characterized by said first and second injector units having proportionally different relative dimensions.

12. The invention as defined in claim 11 and further characterized by said second injector unit having dimensions proportionally larger than the respective dimensions of said first injector unit in the range of 1.33:1 to 2:1.