US3176922A

US3176922A - Spray gun

Info

Publication number: US3176922A
Application number: US42871A
Authority: US
Inventors: Herman W Decker
Original assignee: Individual
Current assignee: Individual
Priority date: 1960-07-14
Filing date: 1960-07-14
Publication date: 1965-04-06
Anticipated expiration: 1982-04-06

Description

H. W. DECKER April 6, 1965 SPRAY GUN Filed July 14, 1960 2 Sheets-Sheet l ELIE" 7 Emmy M Q. mun, 1 h

INVEN TOR. HERMAN W. DECKER r- %-z, W AT TQRNEYS April 6, 1965 H. w. DECKER 3,175,922

SPRAY GUN Filed July 14, 1960 2 Sheets-Sheet 2 INVENTOR.

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ATTORNEYS United States Patent 3,176,922 SPRAY GUN Herman W. Decker, 1 .0. Box 1318, Stuart, Fla. Filed July 14, 1960, Ser. No. 42,871 Claims. (Cl. 239-112) This invention relates to fluid blending and dispensing devices and more particularly to devices for blending two liquids which rapidly react when blended to become substantially more viscous than when in the unblended state.

A copending patent application for Method and Apparatus for Applying Liquids, Serial No. 809,166, filed April 27, 1959, now Patent No. 3,079,090, by Herman W. Decker discloses a spray gun in which two reacting fluids are fed to a blending chamber within the gun, are thoroughly intermixed by a beater of basket form and are rapidly ejected from a nozzle contiguous to the chamber. The constituents blended in this gun upon reacting become considerably more viscous than in their unblended state as they are fed to the gun and in practice may become solid, advantageously as a foamed solid. Examples of the materials which may be dispensed include epoxy polyester and polyurethane formulas which are foamed in place by blending a catalyst accelerator and a resin. The nature of the resulted foam and the speed with which it is formed is dependent upon the proportioning of the constituents. Accordingly, control of this proportioning as the constituents are fed to the blending chamber is extremely important. Frequently, reaction times of but a few seconds are utilized. Under these conditions there is some tendency for the blended materials to build up within the dispensing unit and ultimately impede its function.

Objects of the present invention are to improve liquid blending and dispensing apparatus, to facilitate the manufacture of such apparatus, to eliminate or minimize the regions within such apparatus wherein a build-up of material can occur, to avoid Waste of material, to improve the control of the material dispensed in the apparatus, to facilitate the cleaning of the apparatus, particularly without disassembly thereof, and to maintain constant the viscosity of the fluids supplied to the apparatus.

In accordance with the above objects two exemplary forms of blending and dispensing apparatus are disclosed, one constituting a spray gun adapted for manual support and manipulation and the other a void filler particularly adapted for dispensing blended fluids to a chamber which is to be filled with the intermixed materials. The features embodied in these examples of the present invention include valving arrangements which enable two or more fluid supplies to be connected to a dispensing mechanism such that the fluids can be recirculated when the mechanism is not conditioned for blending and dispensing. This is particularly advantageous where the fluids tend to alter their physical characteristics when they are permitted to lie dormant in the supply lines to the dispensers inasmuch as they are continuously fed to the dispensers and either blended and dispensed therefrom or, during those periods when dispensing is not occurring, are returned to supply reservoirs without alteration in their physical characteristics.

Another feature of the invention is a valve construc tion and orientation which admits the fluids which are to be blended directly into the blending chamber without requiring passages from the valve to the chamber. This construction eliminates one area in which a build-up of fluid can occur to impede the eflicient operation of the apparatus.

An additional feature resides in a valve structure which permits the fluid fed to the dispenser to be recycled there- $316322 Patented Apr. 6, 1965 "Ice from. This internal recycling creates no dead space in the line from the recycle location to the feed location and all material not fed for dispensing is returned to the fluid supply.

A further feature resides in a purging system whereby the regions of the dispenser contacted by the reacting constituents is flushed by a solvent for the fluids dispensed from the apparatus. This solvent purges material which has passed the valving structures whereby the build-up of material can be eliminated without disassembling the dispenser or interrupting its use for any substantial interval. Subsidiary features include the valve constructions utilized, the interlocking of valving actions, particularly those for the purging material and the reacting materials, and the driving means for the several movable elements in the apparatus.

The above and additional objects and features of this invention will be understood more fully from the following detailed description when read with reference to the accompanying drawings wherein:

FIG. I is a sectioned elevation of a gun form of blending and dispensing device according to this invention with certain portions broken away to reveal more clearly the details of construction;

FIG. II is a cross section of the gun of FIG. I taken along the line IIII;

FIG. III is a plan view of one valve construction suitable for incorporation in the dispenser of FIG. I and affording a purging connection for the gun;

FIG. IV is a sectioned plan of a second valve construction for the dispenser of FIG. I providing for recirculation of the fluid fed to the gun for dispensing;

FIG. V is a cross section of the valve of FIG. IV and the gun barrel as viewed along the line VV in the direction of the arrowheads;

FIG. VI is another cross section of the valve of FIG. IV and the gun barrel viewed along the line VI-VI in the direct-ion of the arrows;

FIG. VII is a plan view of another form of dispenser according to this invention;

FIG. VIII is a side view of the dispenser of FIG. VII;

FIG. IX is a sectioned plan view of the dispenser of FIG. VII taken along the lines IX-IX of FIG. VIII;

FIG. X is a cross section of the dispenser illustrating the valve construction therefore taken along the line XX of FIG. VII; and

FIG. XI is a sectioned plan view of the valve control and actuating means taken along the lines XIXI of FIG. VIII with the reacting and purging fluid supplies schematically coupled to the apparatus.

In the following description the blending and dispensing apparatus will be described as constructed for utilization of foamed polyurethane formed from a combination of an isocyanate component and a premixed polyester component which, when brought together, react rapidly to form a solidified foam. It is to be understood, however, that other reacting components can also be dispenned by this apparatus and that various modification-s of the apparatus can be incorporated to facilitate such handling including means for establishing a given temperature in the walls of the passages through which the material is transmitted and in altering the sizes of those passages to facilitate such transmission.

The aforenoted copending Decker patent application includes a description of reservoirs and feed pumps. suitable for utilization with the apparatus of this invention when modified to include return lines between the dispenser and the reservoirs. The details of such apparatus are incorporated herein from that application by reference thereto. In general the fluid supplies are temperature controlled reservoirs from which positive displacement pumps feed the fluid o the dispenser, the pumps being arranged so that their delivery rates can be accurately adjusted to elfect a proportioningof the materials which can be delivered from the dispenser. In the following description it will be assumed that all proportioning is accomplished by the adjustment of the pumps and that the valve constructions illustrated are identical for the fluids to be dispensed. However, it is to be understood that proportioning can also be elfected by a suitable choice of relative valve dimension-s, either in combination with pumps of equal capacity or pumps whose delivery rates are proportioned to effect still further alterations in the rates at which the fluids are utilized in this apparatus.

The gun shown in FIG. I includes handle21 and a body or barrel 22. The forward'portion of the barrel terminates in a nozzle 23 having an unrestricted orifice. An enlarged boss 24 adjacent the end of the barrel is threaded at 25 to receive and support an internally threaded nozzle cap 26. The foremost end of that nozzle cap is provided with a series of apertures 27 from which air is emitted to aidin the control of the blended fluids issuing from the nozzle. This air is supplied from a manifold 28 formed between the nozzle and cap 26 in the foremost portion of the encompassed barrel 22. It is fed through perforations in a diffusion disk 29 clamped between the nozzle cap and the boss 24. An air passage 30 extends along the barrel from a main air supply'passage 32 extending along handle 21. In order to increase the flexibility of uses for the gun, it is arranged so that it can be operated as a void filler wherein no spray controlling .air is fed to manifold 28 by cutting off the air supply through passage 30 by means of a gate in the form of a dog point screw 33 fitting into a tapped bore 34 whereby the dog point can be advanced across the passage 3d to close it.

Barrel 22 has a longitudinal bore 35 which is enlarged at its rear to accommodate an air motor 36. As can best be seen in FIG. II the air motor is of the vane type and V rotor 44 of the air motor.

The air motor rotor 44 is cylindrical and coaxial with

bores

35 and 38. Four vanes 45 project radially from the rotor 44 and are fitted to slide along the radial slots 46 in the rotor. These vanes urged outwardly from the axis of the rotor by centrifugal force and are confined in their outward extension by the inner Wall of the motor casing 37. The ports 39 and 42 and the expansion chamber formed by the eccentricity of the interior of the motor chamber with respect to the rotor 44 is arranged such that the vanes encompass a quantity of air in the first A bearing tube 56 extends from the motor chamber toward the nozzle. It comprises end ferrules 57 which have an outer diameter closely approximating the dimensions of bore 35, and an undercut body portion extending between those ferrules. The foremost end ferrule has a flat 53 providing an air pasage from the region between the undercut body of the bearing tube andthe bore so that air fed from passage 30 through, branch passage 59 enters that region and flows past the end ferrule into the blending chamber 61.

Shaft 47 projects through bearing tube 56 and is coupled to a basket shaped agitator 62 having a bell shaped base 63 secured to the shaft in some manner as by a threaded connection. Blades 64 project in a gradually diverging manner from the bell shaped base 63 and terminate in an end ring 65. Rotation of shaft 47 by air motor 46 rotates the agitator 62 to intimately intermix the constituent-s fed to the blending chamber hi and form a stream of those intermixed liquids projected along the bore of the gun and out of the nozzle 23. Fluids are admitted to the blending chamber through apertures such as 66 positioned forward of the bell 63. Where two fluids are intermixed these apertures may advantageously be positioned in radial opposition.

Advantageously, the motor assembly, bearing tube, shaft and agitator are in a unitary assembly which can be withdrawn from'the rear of the gun by unscrewing cap 54. This assembly is readily cleaned and facilitates cleaning of the gun when removed. It is installed by inserting it in the housing, indexing its position therein by fitting key 37a into keyway 38a to align the

air ports

42 and 43, and tightening cap 54 and dog point set screw fill.

FIG. III illustrates one form of valve arrangement controlling the flow from aperture 65. .A boss 67 integral with the body 22 extends from each side thereof and supports the valve structure which includes a bore 5% parallel to the bore 35 into which is fitted a valve liner sleeve 69. The liner is provided as a replaceable element to assure accurately fitting valve parts; however, its function as a casing can be met by the walls of bore 68 where the replacement feature is not utilized. A passage '71 extends from the aperture ss to the bore 68 and across that bore to an extension passage 72 which is closed by maquadrant of their rotation past the inner end of chamber 39. That quantity of air is permitted to expand in the second quadrant of rotation and is expelled through the

ports

42 and 43 through the third quadrant of rotation.

Rotation of rotor 44 drives a shaft 47 extending along the axis of the bore 35. That shaft is mounted in suitable bearings 48 and 49 in the ends '51 and 52 of the motor casing. Shaft 47 projects beyond the 'motorfcasing and is terminated at its rear in a knurled knob 53 which can be spun by the operator, as between the thumb and forefinger, to initiate rotation of the motor if it tends to stall. The motor casing is retained within the enlarged bore of the barrel by means of end cap 54 in threaded engagement with the outer wall of the barrel. When'this cap is tightened, it forces motor casing end 51 against the end of the enlarged bore 38 and compresses an O-ring 55 therebetween to efiect a seal preventing the fiow of air chine screw 73 in a tapped extension of that passage. Sleeve 69 contains opposed transverse apertures 7d and 74 which form inlet and exit or exhaust ports for the valve in registry with the fluid feeding passages 72 and '71, respectively. The end of sleeve 69 is closed by machine screw 75 secured in the tapped end thereof.

The valvebody consists of ashaft 76 which is reciprocated within the bore of sleeve 69 from a position wherein its foremost end is forward of the ports 79 and 74 and the valve is closed to a position where that end is rearward of those ports when the valve is opened to expose the exhaust port to the inlet port. This reciprocation is effected through the operation of a valve controlling trigger 77.

Trigger 77 is connected to a bail '78 which is pivoted by means of pin 31 on a pair of ears 79 secured on the upper surface of barrel 22. Bars 82 project from the bail 78 to engage and embrace a reduced section 83 of the valve body 76 between the main portion of that body and a terminating head 84. When the trigger is drawn toward the handle, the bail moves in a counterclock-wise direction as viewed in FIG. I to retract the valve body 76 and expose ports '76 and 74 to the interior of sleeve 69. Fluid under pressure in the conduit (not shown) to feed coupling (not shown) to inlet port 85 flows through thatport, turns a right angle into extension passage 72, flows into that passage, through valve inlet port 7e, across the interior of valve sleeve 69, through valve outlet port 74 and the passage 71, and thence through chamber port 66 to the blending chamber.

The ears 82 are duplicated on the opposite side of the bail 8 for the second valve of'the gun whereby the trigger constitutes means 'to simultaneously shift the two valve bodies between a closed and opened position by reciprocation of those bodies. Suitable couplings at inlet port 85 are provided as by screwing threaded hose couplings into tapped enlargements of the bore forming port 85. In order to facilitate the closin of the valve by the advance of the valve body F6 past the apertures 7d and 74 under the influence of return spring as, a passage 8? is formed by undercutting the wall of sleeve 65?. This passage prevents a hydraulic block between the end of the valve body '76 and the closed end of the valve sleeve 69 when body 7'6 moves toward the end closure 75 whereby fluid remaining within the valve body adjacent that closure can flow into passage "it as the valve is closed.

The fluid admitted to the passage 71 may tend to accumulate to a limited degree therein, or in extreme instances, may be contacted by the component'with which it is to be reacted to build up a solid material blocking the passage. This blocking material is purged from the passage 71 by admitting a solvent to that passage intermediate the valve and the port on to the chamber and immediately adjacent the valve structure through the fitting 88, shown in FIG. I, coupled to the passage 8% shown in FIG. III. This purging fluid, which should be a solvent such as acetone for the material normally fed through the valve, to be most effective flows along the passage 71 and into the blending chamber 61 from which it is expelled in the same manner as the blended fluids are expelled by the action of the rotating agitator 62 and the flow of air longitudinally of the barrel around the flat 58. Purging fluid can be admitted through the fitting 88 by any convenient valving arrangement (not shown). Fitting 88 has an external configuration adapted to receive a snap type hose coupling whereby the solvent hose can be connected in a matter of seconds for purging. It is a spring biased check valve having sphere 99 as the valve element. Purging is accomplished when the valve 7+5 is closed and while the gun is directed away from the work upon which it is being utilized. The solvent purges all areas beyond valve inlet port 76 since it has access to passage 71, ports 66 and 74, the bleed duct 87, the blending chamber fill, agitator 62 and the noozle 23. After a brief flushing with the purging fluid, the gun will clear itself and be conditioned for normal usage.

As noted above, the reacting constituents frequently require heating to enable them to be accurately controlled and conveniently fed to the blending chamber where the dispensing device is used intermittently. Those fluids in passing from the heated reservoirs to the gun tend to cool and thus change in physical properties, particularly viscosity, so that control of their rate flow into chamber 61 and thus control of the proportioning is impaired. In the past some elforts have been made to overcome this effect by heating the conduit to the gun. This becomes quite awkward in a gun having two or more feed conduits inasmuch as heated hose is stiff and heavy. Another approach in guns dispensing a single fluid has been to provide a recirculating path external of the gun which can be rendered effective to return to the supply a substantial portion of the material in transit to the area in which it is utilized. Such arrangements leave a space from the point the return line is coupled to the supply line to the point of utilization in which the liquid can stagnate. One means of eliminating the need for heated hose and for insuring complete recirculation is shown in the valve construction of FIG. IV. This valve and its counterpart are formed on opposite sides of the gun body. That construction is similar in many respects to the valve of FIG. Ill and can be substituted therefore in the gun of FIG. i. It includes an aperture 66a into blending chamber ela fed by a passage 71a extending from bore 68a in which a valve liner sleeve 69:: is fitted to form a valve casing. An extension passage 72a is in alignment with passage 71:: and is intersected at right angles at a passage from an inlet port 85a to provide a feed conduit. Valve sleeve 69a includes

opposed apertures

73a and 74a forming inlet and exit ports in registry with

passages

72a and 71a. A

screwi'da closes the end of valve sleeve 69a and a screw 73a closes the end of passage 72a. Valve body 91 differs in its construction from body 76 in that it includes a milled return passage 92 which extends longitudinally of the body so that when the valve is in its closed or forwardrnost position as shown in solid lines, fluid fed through the port a flows through passage 72a into return passage 92 in the valve body, thence through exhaust' conduit or passage 93 and a registering aperture or recycle port 94 in the sleeve 68a to the tapped bore 5 arranged for reception of a suitable threaded hose coupling (not shown). A groove 96 is cut in the rearmost end of valve body 91 and is arranged to be engaged by a slotted ear 82a on bail 78a in the gun triggering system. The valve body orientation can be established and maintained to register passage 92 with ports 76a and 94 by the bottomingof the edge of ear 82a in groove 95.

The drawing of the trigger 77 toward the handle 21 retracts the bodies of the paired valves to draw the forwardmost ends to the position shown in phantom wherein they open the feed passage paths from passages 72a across the interior of valve sleeves 68a to ports 74a and passages 71a, thereby enabling the continuously flowing fluids to be fed to the blending chamber of the gun through ports 66a. When the trigger is released, it is urged forward by return spring 86 to carry valve bodies d1 to the position shown in solid lines to close the trans verse passages and register the return passages 92 with sleeve inlet ports 79a and recycle ports b4. Return of the valve bodies is permitted despite the accumulation of fluid within the sleeves by relief passages 97 which may be a milled flat on the side of the bodies 91 adjacent the ports 71a and extending to those ports from the ends of the bodies when they are in the full forward position.

With the construction of FIG. IV a virtually uninterrupted flow of fluid through the conduit 85 is afforded. When the valve is closed, the fluid flows along the path shown in the arrowheaded line shown in FIG. IV from the inlet port 85 through return passage 92, the recycle port 91 and the exit passage 93. When open, that fluid is dispensed and the recycle path is cut oil. No portion of the fluid path retains fluid during recycling.

The relationship of the valve elements is illustrated in FIGS. V and VI when the valve is closed. The fluid enters the underside of the boss 67a in which the valve is situated through the hose coupling (not shown) in the enlarged tapped bore 98 and port 85a to passage 72a, inlet port 74a and return passage 92, all as seen in FIG. VI. In flowing longitudinally of valve body 91 along re turn passage d2. the fluid reaches sleeve recycle port 94 and from there flows into exit passage 93 and the hose coupling (not shown) in enlarged tapped bore in FIG. V.

As in the valve construction of FIG. III, the valve of FIGS. IV, V and VI also is provided with a means of passing purging fluid through the passage 71a, inlet port: 66a and the blending chamber 61. A fitting 88a for this purpose communicates with a passage 8% intersecting the passage 71a. The function of this purging fitting and passage is the same as described for FIG. III and will operate in this manner.

FIGS. VII through XI disclose another form of blending and dispensing apparatus of the type somewhat related to the gun of FIGS. I through VI and include a new form of valve for the constituents which can be adapted to application in a gun. Accordingly, it is to be understood that the illustrative valve constructions are to be considered interchangeable by the exercise of mechanical skill between the two dispensing devices illustrated.

This valve is of cylindrical form and contains separate passages within its cylindrical body through which both the dispensed fluid and the flushing solvent therefor pass. All dispensed fluid fed to. the dispensing unit flows through the valve body. In the recycle position the fluid path is closed by shifting the solvent passage in the At that time a path through the body' valve body from the solvent inlet port and the valve port to the blending chamber and by repositioning the passage through which the dispensed fluid was recycled to pass that fluid from the feed line to the blending chamber valve port. The construction of the valve provides an inherent interlock which precludes the simultaneous feed of solvent and dispensed fluid to the region from which material is dispensed, and thereby avoids any work spoilage through operators error. Since solvent llows through all portions of the valve and dispensing region, thorough flushing and cleaning is assured. The passage in the valve body in essence ports directly into the dispensing region to eliminate coupling passages in which the dispensed fluid is permitted to lie dormant.

This feature coupled with the separation of the solvent and dispensed fluid paths enables all dispensed fluid to be. properly conditioned both physically and chemically for utilization since it is material fed directly from its supply reservoir and not even the initially dispensed portion is intermixed with the purging material.

As seen in FIGS. VII through 1X the apparatus comprises an air motor housing 1191 containing an air motor of much the same construction as that discussed with respect to FIG. 1 including a rotor 102 coupled to a rotating shaft 103. The shaft extension is coupled to a basket shaped agitator 1114 within a blending. chamber 105 which is contiguous with a'spout or nozzle 1% from which the blended fluids issue.

This apparatus is not intended for spraying the blended fluids but rather for pouring those fluids into confining forms as in molding operations. The blending chamber is encompassed by a body 107 to whichis secured the motor housing 191 as by means of tubular extension 110 enclosing bearing 1 a and clamped by thumb screw not shown such as a combination of levers and counter balancing means for manipulation into molds or can be mounted as a stationary apparatus.

As can best be seen in FIG. IX the body 107 includes a pair of supply passages 111 having tapped counter bores for the reception of suitably threaded supply hose cou plings 112, and extending into passages 113 which are generally parallel to the axis of blending chamber 165. Passages 113 each intersect valve receiving bores 115 which are perpendicular to the axis of blending chamber 165 and to the axes of passages 113 and'substantially tangent to the chamber 105 whereby their walls intersect the walls defining the blending chamber to form ports 118 into that chamber. Recycle passages 117 extend radially from the bores 115 as do passages 113 so that the ports 118. The sleeves are'also formed so that those portions which intersect the walls of the blending chamber are cut away to avoid projecting into cylindrical region forming the blending chamber whereby the agitator ring 124 can be moved along the chamber when the motor unit 1% is removed from body 107.

A cylindrical valve body 125 closely fits within each of the sleeves. Each body includes a pair of radial pas- 1

sages

127 and 128 which intersect and are positioned line or when rotated 90 with the port 121 to the supply axes of passages 113 are in quadrature relationship to both the recycle passages 117 and the apertures 118 from the valve-bores into the blending chamber. The axes of

passages

113 and 117 define a plane parallel to the axis of chamber 105. The recycle passages 117 and the apertures 118 into the blending chamber are diametrically opposed across the valve bores 115.

Tubular valve liners 119 fit within the bores to form replaceable valve casings and are apertured so'that when fixed in their proper position their apertures register with the intersections of the

passages

113 and 117. and the port 118 to the bore 115. The liners provide

valve ports

121, 122 and 123 as continuations of the supply passages 113, the recycle passages 115 and the chamber blending chamber.

line and the port 123 in the sleeve wall leading into the Thus when the valves are in the position shown in FIG. IX, fluids are fed into passages 111, fiow along passages 113,-then pass through inlet port 121 or the sleeve and into the radial passages 12.7. From radial passages 127 in the valve body, the fluids flow to the recycle passages 128, through sleeve recycle port 122 to recycle passages 117 and are returned to the material supply reservoir (by means not shown). As the left hand valve body 125 is rotated clock-wise 90 and the right hand valve body 125 is rotated counterclock-wise 90 as viewed in FIG. IX, passages 123and 127 therein respectively register with inlet port 121 and blending chamber port. 116 whereby the fluids fed through the supply passages 111 and passages 113 enter passages 128, now functioning as feed passages instead of recycle passages, then passages 127 and'pass through sleeve port 123 into chamber1tl5 where they then are blended and expelled from the nozzle 1%.

As best seen in FIG. X the cylindrical bodies 125 are oriented axially in the valve liners 119 by retainer rings 132 which are resiliently maintained in circumferential grooves adjacent the ends of those bodies and have their faces bearing on the outer surfaces of

housing'1t37 Gear segments

134 and 135 are also secured to the valve bodies 125 so that their pitch lines are tangent to each other as best seen in FIG. VII whereby the rotation of one Valve body causes simultaneous opposed rotation of its opposite member through the coupling afforded by their intermeshing gear teeth. A crank 136 extends from segment'134. Crank 136 is connected by sliding coupling to a pin 137 on piston rod 138 which reciprocates along the axis of cylinder 139 as best seen in FIG. XI.

The valve actuator and control assembly 1119 includes a pilot valve 141 controlled by knob 14.2 which is incorporated in the housing 143 containing cylinder 139. Air is supplied to the housing through a coupling engaging the housing at boss 144 and is supplied to the air motor from the housing through a coupling engaged at boss 145.

Neither of the couplings nor the hose connections for the air supply are shown in the drawings.

Referring to FIG. XI air supply passage 14-5 in boss 144 feeds all of the air from the main supply through the chamber 147 containing the body of the pilot valve. A portion of that air passes from the chamber through the air motor supply passage 14% and thence to boss 145. Chamber 147 is formed as a bore parallel to the cylinder 139, its lower end is closed by machine screw 149 and its upper end is closed by bushing 151 through which extends a shaft 152 coupling the pilot valve control knob 14-2 to the pilot valve control body 153. The valve body is formed withfianged ends 154 and 155 having diameters closely approximating the inner diameter of bore 147.

These flanges are grooved for the reception of O-rings 156 which provide seals preventing the flow of air around the flanges. I a

With knob 14-2 depressed as shown in FIG. XI, piston 158 is retracted and the valve bodies 125 are positioned as shown in FIG. IX to recycle the fluid fed to the dispenser. Retraction of piston 158is caused by feeding the air supply to the cylinder 139 below the piston through passage 159. The piston, therefore, moves upward in the cylinder forcing the air above it through the'passage 161 and into the bore 147 from which it escapes through the vent 162 above the upper flange 154 on pilot valve153. When it is desired to open valves 125 to the blending chamber, pilot valve control knob 142 is raised. This moves the valve body 153 so that its upper flange 154 is above passage 161 and its lower flange 155 is above passage 159. When in this condition, the air supply is fed from chamber 147 through passage 161 to the upper surface of piston 153 forcing that piston downward and the air below that piston is permitted to escape through that passage 159 into bore 147 and to the atmosphere through vent 163. The full travel of piston 158 in cylinder 139 carries crank 136 around an arc of 90 around the axis of left hand valve body 125 and by virtue of the geared coupling between

gear segments

134 and 135 carries the right hand valve body 125 through a similar arc in the opposite direction.

In operation this construction enables fluid to be recycled continuously while it is not being blended and dispensed by feeding it through the inlet couplings 112 and by returning it to the reservoirs through the recycling couplings 116. By the operation of an easily manipulated pilot valve, the bypassing valves are rapidly shifted to a position supplying the fluid to the blending chamber and the fluid is intermixed by the air motor driven agitator and ejected from that chamber.

The valve construction for controlling the reacting constituents as shown in FIGS. VII through XI is such that no passage is required from the passage in the valve body to the blending chamber. Thus, no region is available in which the fluid can lie dormant, deteriorate to an unusable state, and build up to obstruct the feed to the chamber. However, even in a construction as illustrated, the blended constituents can build up on the inner walls of the nozzle 106 and to a limited degree on the portions of the agitator 164. Such material can be expelled from the dispenser by periodically admitting a solvent into the blending chamber for purging purposes. A solvent inlet port 169 is shown in FIG. X including a tapped bore for the reception of a suitable coupling. The bore has an extension 171 which intersects with purging

fluid passages

172 and 173 extending to apertures or purge ports 174 and 17 in valve liners 119. As shown in FIGS. IX and X valve bodies 125 are each provided with flats 176 extending longitudinally of the bodies and in quadrature with passages 127. These flats provide a secondary or purge liquid passage 170 defined by the inner wall of liner 119 and the flat walls 176 of the valve body. When in registry with ports 123, they complete a path for the purging liquid. Thus during recycling the purging liquid can flow from port 169 through the

passages

171 and 172, through

ports

174 and 175 in the liner walls, then along the passages 170 formed between the inner wall of the liners 119 and by the flats 176, to the blending chamber inlet ports 123 from which the solvent passes into the blending chamber to effect the purging action.

The valves of FIGS. VII, VIII, IX and X thus have

primary passages

127 and 128 in their valve bodies which are normal to the longitudinal axes of those bodies and secondary passages between fiat 176 and the valve casing which extend longitudinally. The valve ports are oriented in the casing so that they register with those passages. Inlet port 121, exit or exhaust port 123 and recycle port 122 having their centers in a common plane perpendicular to the body and easing axes and coinciding with the plane defined by the axes of

passages

127 and 128 of the valve bodies. Exit port 123 coincides with chamber port 116 to avoid a pocket in which material can accumulate.

Purge ports

174 and 175 are aligned longitudinally of the valve casing with exhaust port 123 so that the purge passages in the valve bodies extend between those ports when the valves are recycling.

FIG. X includes schematic representations of the several liquid supplies including first and second reacting liquid supplies and feed conduits 1'77 and 178 from those supplies to the feed couplings 116 to body 167. A purging liquid supply is also shown with a purging liquid conduit 131 having a shutoit valve 182 and extending to a coupling 1113 to housing 1617.

The valve construction of FIGS. VII to X positively interlocks the purging fluid feed with that of the reacting constituents so that the fluid cannot be supplied to the blending chamber when the constituents are being supplied and vice versa, yet no alteration in the condition of the valve is necessary once it is in the recycling position in order to purge the blending chamber. No control for the solvent has been shown. In the usual operation a separate valve is provided. However, the solvent can be supplied at the port 169 in any convenient manner with assurance of control to avoid detrimental intermixing inasmuch as the rotation of the valve bodies closes the passage for solvent from that port to the blending chamber by displacing the flat areas 176 from their registered position with the

apertures

174 and 175.

It is to be appreciated that valves of the type shown in FIGS. V11 through X can be incorporated in a dispenser arranged for hand manipulation either as a spray gun or as a hand controlled mixing head or nozzle having no directing air supply with the same advantages enumerated above of eliminating the passages in which material is rendered useless between the valve and the blending chamber.

Many modifications of the above constructions can be made without departing from the spirit and scope of this invention. Accordingly, this description and the drawings should be read as illustrating the drawings and not in a limiting sense.

Having described the invention, I claim:

1. In combination, a supply of a first liquid, a supply of a second liquid, a liquid dispenser, a dispensing nozzle having an orifice, a dispenser body supporting said nozzle, said body having a plurality of primary supply passages and a blending chamber having longitudinal walls in communication with said supply passages and said nozzle, a fluid conduit from said first liquid supply to a first of said primary supply passages, a fluid conduit from said second liquid supply to a second of said primary supply passages, a supply valve adjacent said longitudinal walls of said chamber and individual to each supply passage for controlling the flow to said chamber of the liquid to be dispensed, each supply valve dividing a respective supply passage into a first and second section, each of said first sections extending from said valve to said respective fluid conduit, each of said second sections being open to said chamber and extending from said valve to said chamber wall, said body having a secondary passage individual to and intersecting and communicating with said second section of each of said first and second primary passages, a supply of liquid solvent for said first and second liquids, and means to couple said supply of solvent liquid to said secondary passages.

2. A combination according to claim 1 wherein said body has a recycle passage, and said valve couples said primary and recycle passages when it closes the primary passage to said chamber.

3. A combination according to claim 1 wherein said secondary passages each communicates with a respective second section of each of said first and second primary supply passages through said supply valve, said secondary passages each intersecting its respective supply valve at a position in said dispenser body spaced from the intersections of said first and second sections of said primary supply passage with said valve, including a body for each supply valve movable between a first and a second position, each of said valve bodies having a purge passage extending from said secondary passage intersection with said valve to said intersection with said valve of said second section of said primary supply passage and means to isolate said first section of said primary supply passage supplemental passage.

1 1. from said second section when in said first position, each of said valve bodies when in said second position isolatports in said chamber wall through a passage open to ing said secondary passage intersection with said valve and placing said first and second sections of said primary supply passage in communication, and means for shifting said valve bodies between said first and second positions.

4. Apparatus according to claim 3 wherein said shifting means imparts rotational motion to said valve bodies.

. return passagewhen said body is in said first position, and

a fluid conduit from each of said return passages to said respective liquid supply. V

6. In combination, a supply of a first liquid, a dispenser for said first liquid comprising a nozzle having an orifice from which liquid is dispensed, a chamber having longitudinal walls and an end transverse of said walls in communication with said orifice, a fluid supply passage to said chamber terminating in a port at the chamber, a conduit from said supply of first liquid to said fluid supply passage, a valve in said supply passage, said valve said chamber interior, and means coupled to each of said valve bodies for'simultaneously shifting said bodies between said first and second positions.

9. A device according to claim 8 wherein said body has liquid passages extending to said chamber ports intermediate said valves and said'ports' into said chamber.

10. Apparatus for blending and dispensing liquids comprising a body containing a blending chamber having longitudinal walls, a pair of liquid feeding conduits in said body to said chamber and intersecting said longitudinal walls of said chamber, first valves in said body a for controlling the flow oi each of the liquids to be blendbeing oriented adjacent said longitudinal walls of said chamber to divide said supply passage into a first and second section, said first section extending from said valve 7 to said conduit, said second sec-tion being open to said chamber and extending from said valve'tosaid chamber wall, a supply of liquid solvent forrsaid first liquid, a suplplemental fluid passage intersecting and communicating with said second section of said fluid supply passage, means coupling said solvent supply to said supplemental passage, and means to control the flow of solvent in said 7. A combination according to claim 6 wherein said supplemental passage communicates with said second section of said supply passage through said valve, 'said supplemental passage intersecting said supply valve at a position spaced from the intersection of said first and second sections of said supply passage with said valve,

and including a body for said supply valve movable between a first and a second position; said valve body having a passage extending from said supplemental passages intersection with said valve to said intersection with said 8. Apparatus for blending and dispensing liquids comprising a body having a blending chamber having longitudinal Walls, a plurality of ports in said longitudinal walls into said chamber and a plurality of passages communicating with each port, a nozzle in communication with said chamber, valve casings in said body adjacent said longitudinal walls of said chambena valve body within each casing and movable from a first to a second position therein, each of said casings being intersected by passages in said body to form an inlet, an exhaust and a recycle port, each valve body having a passage extending from said inlet to said recycle port when in said first position,

walls of each valve body isolating its associated recycle port and exposing said exhaust port to said inlet port when in said second position, each of said valve' casing exhaust ports being in communication with one of said ed to said charnber through each conduit, each of said first valves being located adjacent the longitudinal walls of said blending chamber to minimize the length of feeding conduit between said valves and said chamber, said body having a solvent feeding conduit intersecting a feeding conduit intermediate said first valve for said feeding conduit and said chamber in the vicinity of the first valve for said feeding conduit, a second valve on said body to con-trolthe flow or" a solvent forisaid blended liquids into said solvent feeding conduit in the vicinity of the first valve for said feeding conduit, a liquid recycle conduit in said body from each valve to an external conduit coupling, and an external fluid conduit coupling from each feeding conduit, said valves when closed to the flow of liquid to said chamber having passages for the flow of liquid entering said feeding conduit to said recycle conduit. 7 V 1 11. A combination for blending and dispensing liquids comprising a first liquid supply, a second liquid supply, a dispenser body, a liquid supply conduit from each liquid supply to said body, said body having a blending chamber having longitudinal walls and a feed conduit from each supply conduit to said chamber and intersecting said chamber at said longitudinal walls, a valve in each feed conduit, each of said: valves being mounted on said body adjacent said longitudinal walls of said chamber torminimize the length of feed conduit between said valves and said chamber, a supply of solvent for said liquids from said first and second'supplies, a solvent supply conduit from said solventsupply to said body, a solvent conduit in said body from said solvent supply conduit to each'of said feed conduits intermediate said valves and said chamber, a recycle'conduit to each valve in said body, and a return conduit from each recycle conduit to said respective liquid supplies, said valves opening a path 7 from said supply conduits to said chamber and closing said solvent conduits when in a first position and when ma second position opening a path through said feed conduits to said recycle conduits while closing said feeds conduits to said chamber and opening said solvent conduits to said chamber. (7 1 a 12. A liquid blending and" dispensing apparatus comprisinga body having a blending chamber, a plurality of liquid feedports into said chamber and liquid feed conduitsto said'ports, a-valve casing in said body for each feed conduit,"a valve body within said casing having an inlet port from-said 'feed'conduit, an exit port to said .feed conduit and a recycle port spaced longitudinally V tudinally therein between said' inlet and recycle ports when in a-first position, said'apparaitus' body having recycle conduits extending" from fsaidu-ecycle ports, and

means to reciprocate said valvebodies to a second position closing said inlet ports from said recycle ports and opening said inlet ports to said exit ports.

13f. Apparatus according to claim 12 includingan apparatus'body havin'g'purging liquidconduits to said feed,

13 conduits intermediate said valve bodies and said chamber.

14. A liquid blending and dispensing apparatus comprising a body having a blending chamber, a liquid feed port into said chamber and a liquid feed conduit to said port, a valve casing in said body, a valve body within said casing having aninlet port from said feed conduit, an exit port to said feed conduit and a recycle port spaced longitudinally from said inlet port and arranged for reciprocation therein, said valve body having a passage extending longitudinally therein between said inlet and recycle ports when in a first position, said apparatus body having a recycle conduit extending from said recycle pont, and means to reciprocate said valve body to a second position closing said inlet port from said recycle port and opening said inlet port to said exit port.

15. Apparatus according to claim 14 including an apparatus body having a purging liquid conduit to said feed conduit intermediate said valve body and said chamber.

References Cited in the file of this patent UNITED STATES PATENTS Hoyt June 8, Fleming Sept. 23, Downs July 31, Magowan Jan. 24, Einbecker June 13, Janssen Dec. 18, Kopperschmidt Nov. 10, Friend Feb, 16, Wilson Apr. Q4, Standlick July 4, Dupler et a1. July 11, Paulsen July 11, Reed Jan. 16, Edwards May 22, Edwards et a1. July 3, Wilson Oct. 9, Decker Feb. 26,

Claims

1. IN COMBINATION, A SUPPLY OF A FIRST LIQUID, A SUPPLY OF A SECOND LIQUID, A LIQUID DISPENSER, A DISPENSING NOZZLE HAVING AN ORIFICE, A DISPENSER BODY SUPPORTING SAID NOZZLE, SAID BODY HAVING A PLURALITY OF PRIMARY SUPPLY PASSAGES AND A BLENDING CHAMBER HAVING LONGITUDINAL WALLS IN COMMUNICATION WITH SAID SUPPLY PASSAGES AND SAID NOZZLE, A FLUID CONDUIT FROM SAID FIRST LIQUID SUPPLY TO A FIRST OF SAID PRIMARY SUPPLY PASSAGES, A FLUID CONDUIT FROM SAID SECOND LIQUID SUPPLY TO A SECOND OF SAID PRIMARY SUPPLY PASSAGES, A SUPPLY VALVE ADJACENT SAID LONGITUDINAL WALLS OF SAID CHAMBER AND INDIVIDUAL TO EACH SUPPLY PASSAGE FOR CONTROLLING THE FLOW TO SAID CHAMBER OF THE LIQUID TO BE DISPENSED, EACH SUPPLY VALVE DIVIDING A RESPECTIVE SUPPLY PASSAGE INTO A FIRST AND SECOND SECTION, EACH OF SAID FIRST SECTIONS EXTENDING FROM SAID VALVE TO SAID RESPECTIVE FLUID CONDUIT, EACH OF SAID SECOND SECTIONS BEING OPEN TO SAID CHAMBER AND EXTENDING FROM SAID VALVE TO SAID CHAMBER WALL, SAID BODY HAVING A SECONDARY PASSAGE INDIVIDAL TO AND INTERSECTING AND COMMUNICATING WITH SAID SECOND SECTION OF EACH OF SAID FIRST AND SECOND PRIMARY PASSAGES, A SUPPLY OF LIQUID SOLVENT FOR SAID FIRST AND SECOND LIQUIDS, AND MEANS TO COUPLE SUPPLY OF SOLVENT LIQUID TO SAID SECOND PASSAGES.