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Publication numberUS3327949 A
Publication typeGrant
Publication dateJun 27, 1967
Filing dateSep 17, 1965
Priority dateSep 17, 1965
Also published asDE1621928A1
Publication numberUS 3327949 A, US 3327949A, US-A-3327949, US3327949 A, US3327949A
InventorsEull Marvin J
Original AssigneeGray Company Inc
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Spray gun
US 3327949 A
Abstract  available in
Images(3)
Previous page
Next page
Claims  available in
Description  (OCR text may contain errors)

June 27, 1967 M. J. EULL. 3,327,949

SPRAY GUN Filed Sept. 17, 1965 3 Sheets-Sheet 2 United States Patent 3,327,949 SPRAY GUN Marvin J. Eull, St. Michael, Minn, assignor to Gray Company, Inc, Minneapolis, Minn., a corporation of Minnesota Filed Sept. 17, 1965, Ser. No. 488,186 16 Claims. (Cl. 239-412) This invention rel-ates to a spray gun for pain-ts, lacquers and like coating materials and, more specifically, to an improved airless spray gun that includes a dusting nozzle for directing a jet of compressed air against a surface to dislodge and remove particles of dust, dirt and the like from the surf-ace prior to painting.

It has long been recognized that if paint is sprayed directly onto a dusty or dirty surface, the quality of the finish will be impaired. For this reason, various equipment has been used in the past by spray painters to clean the surfaces to be painted before spraying. However, as the cleaning equipment was not associated with the spray gun and usually could not be conveniently carried by the painter while he was using the spray gun, the pre-cleaning of the surfaces was a time consuming, and often neglected, operation since the painter was required to put aside his spray gun, pick up and use the cleaning equipment, and then take up the spray gun again. Furthermore, since spray painters are relatively highly paid workmen, the nonproductive time required for this cleaning operation increases the cost of the painting and thus total manufacturing costs.

However, some skilled operators of conventional air spray guns have sometimes been able to reduce the time required for cleaning by using their spray guns to clean the surfaces. This shortcut is possible since it was found that when the trigger of the air spray gun was barely depressed, only a jet of compressed air escaped from the spray nozzle of the gun. Nevertheless, while this jet of compressed air could be utilized to clean a surface, the painter has to be extremely careful and skilled in order to obtain and maintain a jet that has sufficient velocity and volume to clean satisfactorily but yet does not have any paint entrained therein. Moreover, this method of using the spray gun to clean obviously could not be utilized with airless spray guns since compressed air is never present in or around the spray nozzle of the gun. Therefore, it is apparent that there has been a long-standing need in this industry for equipment which can be exepditiously and conveniently utilized to pre-clean surfaces to be painted and which requires a minimum of time and skill on the part of the painter for satisfactory operation.

Accordingly, it is a primary object of the present invention to provide a novel improved spray gun which permits the facile removal of dust and dirt from the surface to be painted by the gun, while eliminating the aforementioned loss of time and inconvenience heretofore associated with this pre-cleaning operation.

Another object of the present invention is to provide a new spray gun having a dusting nozzle incorporated therein, which is completely separate from the paint spraying nozzle and which is adapted to emit a high velocity jet of compressed air therefrom that may be utilized to clean a surface before paint is applied thereto. A related object of the present invention is to provide an improved airless spray gun that incorporates therein a dusting nozzle without significantly increasing the size or weight of the gun or modifying the outer configuration of the gun.

Another object of the present invention is to provide an improved spray gun which includes a dusting nozzle that is arranged and directed so that the jet of compressed air emitted therefrom impinges upon substantially 3,327,949 Patented June 27, 1967 ice the same portion of the surface as the paint being sprayed from the spray nozzle whenever the gun is held in its normal position for painting.

Still another object of the present invention is to provide a new improved airless spray gun including a dusting nozzle and a valve for controlling the flow of compressed air through the dusting nozzle that is separate from the conventional trigger mechanism utilized to control the flow of paint through the spray nozzle. A related object of the present invention is to provide a valve for con trolling the flow of compressed air through the dusting nozzle which cooperates with the valve mechanism that controls the flow of paint through the spray nozzle whereby simultaneous flow through both the dusting nozzle and spray nozzle is not possible.

Another object of the present invention is to provide an improved airless spray gun in which compressed air from a single source is utilized, in a unique manner, to control both the flow of paint through the spray nozzle and to clean the surface to be painted, thereby minimizing the external connections to the gun and greatly simplifying the operation of the gun.

Another object of the present invention is to provide an improved spray gun which may be relatively inexpensively manufactured and competitively marketed and which substantially reduces the time and inconvenience heretofore required to clean particles of dust, dirt and/ or old paint from a surface prior to the painting thereof.

These and other objects of my invention will be apparent from a consideration of the accompanying specification, claims and drawings of which:

FIGURE 1 is a vertical cross-sectional view of the improved spray gun of the present invention showing the components thereof in a position they assume when the gun is not in use;

FIGURE 2 is a plan view, partially in vertical crosssection, of the improved spray gun of the present invention showing the components thereof in the position they assume when a jet of paint is being sprayed from the spray nozzle;

FIGURE 3 is a plan view, partially in vertical crosssection, of the improved spray gun of the present invention showing the components thereof in the position they assume when a jet of compressed air is being sprayed from the dusting nozzle;

FIGURE 4 is an enlarged vertical cross-sectional View of the spray nozzle assembly utilized in the improved spray gun of the invention;

FIGURE 5 is a partial horizontal, cross-sectional view of the trigger member showing the trigger stop member moved from the position shown in FIGURE 3; and

FIGURE 6 is a vertical cross-sectional view of the pilot valve assembly shown in FIGURES 1-3.

Referring now to the drawings, the new improved spray gun of the present invention comprises a main stock 10, a butt or handle 12, a trigger 14, and a spray nozzle assembly 16. The stock 10 includes a hook 18 formed along its upper edge from which the gun may be hung when not in use.

The nozzle assembly 16 is attached to the front end 20 of the stock 10 and includes a main generally tubular member 22 having internally and externally threaded ends 24 and 26 and a central portion 28 having a relatively larger external diameter. As shown, the end 24 closely fits through an aperture 30 in the front end 20 of the stock so that the central portion 28 tightly abuts the front end 20, with a gasket 29 positioned therebetween. Lock nut 32 or like fastening means cooperates with external threads on the end 24 to Secure the tubular member 22 to the stock 10. A locating pin 33 also extends between the central portion 28 and the front end to prevent relative rotation therebetween and to insure correct alignment of these parts. This construction permits facile interchange of the nozzle assembly so that the gun may be utilized with both circulating and noncirculating systems.

Referring now to FIGURE 4, a generally cylindrical member 34 has a diffuser tip insert 36 soldered within its front end and has its rearward end threadedly received within the forward end 26 of the tubular member 22 with a sealing ring 38 positioned therebetween, as shown. Members 22 and 34 define an axial cavity 40 therebetween that receives paint, under pressure, from the lateral bore 42 formed in the member 22, as shown in FIGURE 1. The bore 42, in turn, is in communication with a conduit 44, hereinafter more fully described, which is press fit into the outer end of the bore.

The insert 36 has an axial, tapered bore 37 formed therein which terminates at its front end in a standard elliptically shaped orifice. A spherical surface is machined in the rear surface of the insert 36 adjacent the rear, larger end of bore 37 in order to provide a flared seat 39 for the needle valve assembly 46, hereinafter described, that controls the flow of paint through the spray nozzle assembly 16.

An annular cap 48 is internally threaded at 50 so that it may be tightly threaded onto the end 26 of the tubular member 22 and its forward end 52 engages a flange 54 formed on a spray nozzle tip holder 56 whereby, as shown in FIGURE 4, the rear end of nozzle tip holder 56 is tightly pressed against the front end of the member 34, with a gasket 57 positioned therebetween.

The nozzle tip holder 56 includes an axial bore 58, of two diameters, shown at 60 and 62, interconnected by a sloping shoulder 64. An annular spray nozzle tip 66 is positioned within the larger diameter portion 62 so that its front peripheral edge abuts shoulder 64 and has an axial bore 67 therethrough with an orifice formed at its forward end which may be of any conventional configuration or design. Also, an annular spacer 68 is press fitted within the portion 62 0f the bore 58 adjacent the nozzle 66 and has a bore 69 formed therein coaxial with bore 67. The spacer 68 also has a groove formed therein adjacent the bore 58 in which an annular sealing ring 70 is positioned. Moreover, as noted above, the holder 56 is held tightly against the front end of the member 34 by the cap 48, with the gasket 57 preventing leakage therebetween. Of course, "whenever desired, the spray nozzle tip 66 may be quickly and easily replaced by a different sized tip by simply removing the cap 48.

The valve assembly 46, which controls the flow of paint through the nozzle assembly 12, comprises a ball valve 72 carried by the front end of an axially extending valve stem 74. The valve stem is guided in a counterbore 76 in the tubular member 22 and extends through a seal 78 and a gland nut 80 that is threaded in the rear end 24 of the member 22, as shown in FIGURE 1. The stem 74 further extends rearwardly past the trigger 14, through a bore 81 and into a motor chamber 82 formed in the stock portion 10, wherein its rear end is adjustably connected to a piston assembly 84 which is a component of a fluid motor that controls the movement of stem '74, as hereinafter described.

The valve assembly 46 is arranged so that when the spray gun is not in use, the ball valve 72 is biased or pressed against the seat 39 formed in the insert blank 36 thereby closing or blocking the bore 37 therein. However, when the trigger 14 is moved rearwardly by the painter, the valve stem 74 and thus the ball valve 72 are likewise moved rearwardly, away from the seat 39 thereby permitting paint, under high pressure, to flow at a high velocity from the cavity 40 through the bores 37, 67 and 69 and through the orifices formed at the front ends of the bores 37 and 67, whereby the paint may be atomized and sprayed on a surface to be painted.

As shown in FIGURES 1-3, the trigger 14 consists of a symmetrically curved piece of sheet metal 88, which is pivotally mounted at on the stock portion 10 so that the lower end thereof can be swung toward or away from the handle 12. A generally trian-gularly shaped trigger safety stop 91, best shown in FIGURE 5, is mounted on the handle 12 and may be pivoted from the position shown to the position shown in FIGURE 5 which is 90 from that shown in FIGURES 13 wherein its edges 92 contact the longitudinal edges of the trigger piece 88 thereby preventing any accidental rearward movement of the trigger, for example, While the operator is changing the spray nozzle tip. However, when the stop 91 is again returned to the position shown in FIGURES l-3, the trigger may be freely moved rearwardly although, as shown in FIGURE 2, the stop 91 does serve to limit the maximum rearward movement of the trigger. The stop member 91 is provided with a triangular tooth 93 which is adapted to be biased, by coil spring 94, into either of two triangular slots formed in a neck member 95 which is attached to the handle 12 as shown. These slots are disposed 90 apart and are shaped to hold the stop member in either the operating position shown in FIGURES 13, or the safety position shown in FIGURE 5.

As noted above, movement of the trigger 14 controls the flow of paint through the spray nozzle assembly 16 by controlling the position of the valve assembly 46. In fact, the movement of the trigger directly controls the position of a pilot valve essembly 96 which in turn controls the position of the piston 84 within the fluid motor and thus the position of the valve stem 74.

The fluid motor is positioned within chamber 82 which is defined by a recess 98 formed in stock portion 12 and a generally cup-shaped cap 100 that is threadedly received within the recess 98 and has a cylindrical inner extension or side wall 102, as shown in FIGURE 2. When assembled, the thin side wall 102 of the cap extends almost to the bot-tom of the recess 98, and the piston 84, as hereinbefore noted, is connected to the rear end of the valve stem 74 and is mounted for limited axial, reciprocal movement within the cap.

As seen from FIGURES 13, the piston 84 actually comprises two disks 104 and 106 mounted on the threaded, rear end of the stem 74 and a cup-shaped relatively flexible member 108 which is clamped tightly between the disks 104 and 106 so that its outer peripheral portion thereof is continuously in sealing engagement with the cylindrical wall 102. Two sleeves 110 and 112 are also threaded onto the rear end of the stem 74 and are positioned adjacent the disks 104 and 106, respectively. The length and outer diameter of the sleeve 110 is such that this sleeve may slide within the bore 81 thereby acting as a guide and support for the stem 74.

A coil compression spring 113 is positioned within the cap 100 between the base 114- thereof and the disk 106. This spring urges the piston and thus the stem 74 in a forward or valve closing direction (to the left when looking at FIGURES 1-3). Under certain conditions, to be described, the spring 113 is opposed by the pressure of the compressed air within the chamber 82, to the left hand side of piston 84, and a passage 116 which interconnects the chamber 82 with the pilot valve assembly 96.

To prevent leakage of compressed air from the chamber 82, a sealing ring 118 is positioned in the bore 81 about the stem 74, between sleeve 110 and the forward end wall of bore 81, and sealing rings 120 and 122 are positioned between the cap 100 and the stock 10. Also, as shown in FIGURES 13, a reduced diameter portion is formed on the side wall 102 of the cap 100 adjacent the base 114, so that an annular space 124 is defined between the recess 98 and cap 100. This space is isolated from both the chamber 82 and the atmosphere by the sealing rings 120 and 122 for reasons hereinafter explained. Further, a small central opening 125 is drilled in the base 114 to vent the rear portion of the chamber 82 to the atmosphere.

Referring now particularly to FIGURE 6, the pilot valve assembly 96 noted above includes a valving element 126 which is reciprocally movable within axial bore 128 in an annular sleeve 130. This annular sleeve is threaded Within a transverse bore 131 in the handle 12 and carries sealing rings 132 and 134 to prevent leakage between the bore 131 and the sleeve. The axial bore 128 is two diame-, ters, indicated at 136 and 138, which are interconnected by a sloping shoulder portion 140 and which is chamfered at 142 adjacent its inner end. Two sets of radially extending ports 144 and 146 are formed in the sleeve 130 and permit communication between the bore 138 and the passage 116 and between the bore 136 and an enlarged, longitudinally extending passage 148 in the handle 12, respectively.

As shown in FIGURES l-3, a fitting 149 is threaded in the lower end of the passage 148 and is open to permit communication between the passage 148 and the atmosphere whereby when valving element 126 is properly positioned, the air under pressure within the chamber 82 may be exhausted to the atmosphere. The chamfered inner end 142 of the bore 138 communicates with a chamber 150 which in turn communicates with a second enlarged passage 152 in the handle 12. A fitting 154 is threaded into the lower end of passage 152, and is adapted to receive a hose (not shown) or other conduit means which connects the spray gun with an air pump or other source of compressed air.

A bracket 156 is clamped between the fittings 149, 154 and the handle 12 and extends a short distance toward the front of the gun Where it supports a third fitting 158 which is connected to the other end of the conduit 44, described hereinabove. This fitting 158 is adapted to interconnect the conduit 44 with a hose (not shown) or other conduit means which communicates with a paint pump or other source of paint under pressure whereby the pressurized paint may be conveyed through the fitting and conduit 44 into the axial cavity 40 from whence it may pass through the spray nozzle.

Referring again to the valve element 126, which may reciprocally move within the bores 136 and 138 of the sleeve 128, that element includes a head portion 160 which contacts the trigger 14 and which has an outer diameter that is substantially the same as the inner diameter of the bore 136 so as to provide a close sliding fit between the valve element and the sleeve. A sealing ring 162 is carried by the head portion 160 to prevent leakage between the sleeve and the valve element.

Immediately to the right of-valve head 160 (as shown in FIGURES l-3 and 6) are two valve lands 164 and 166 of different diameters which are positioned in bore 136 and chamber 150, respectively, and which are interconnected by a reduced diameter portion 168. The land 164 cooperates with the shoulder .140 to control the flow of air between passages 116 and 148 while the land 166 cooperates with the chamfered portion 142 to control the flow of compressed air from the passage 152 (through chamber 150) to passage 116.

A relatively small diameter stud 169, with a bolt 170 threaded thereon, extends to the right from the land 166 and is surrounded by one end of a coil compression spring 171 which is positioned within the cavity 150. The spring abuts land 166 and urges the valve element 126 to the left (as shown in FIGURES 1-3) against the counteracting force applied to the valve element by the trigger 14.

Thus, when the operator releases the trigger 14, spring 171 biases the valve element 126 to the left until land 166 contacts the chamfered portion 142 and thereby blocks communications between passage 152 and chamber 82. However, at this time, land 164 is positioned to the left of shoulder 140 thereby permitting chamber 82 to comrnunicate with the atmosphere through passages 116 and o 148 whereby spring 113 may bias the piston 84, and thus the stem 74 and ball valve 72 to the left, blocking the flow of pressurized paint through the spray nozzle. When the operator pulls the trigger 14 back toward the handle 12, the valve element 126 is moved to the right thereby causing land 164 to contact shoulder and land 166 to move away from portion 142 whereby communication between chamber 82 and the atmosphere is blocked while compressed air from passage 152 may enter chamber 82. The compressed air causes the piston 84 to move to the right against the bias of spring 113 and this, in turn, causes the stem 74 and thus the ball valve 72 to move away from the seat 39 in the insert 36, as shown in FIGURE 4, thereby permitting flow of pressurized paint through the spray nozzle.

A counter bore 172 is formed in the stock 10 coaxial with the bore 131. This counter bore permits communication between the chamber and a short passage 174 which in turn communicates with the annular space 124 formed between the cap 100 and the bore 98 as hereinbefore described. A passage 176 connects the annular space 124 with a dusting nozzle 17 8 which is threaded into a bore drilled in the front of the hook 18. The dusting nozzle 178 is positioned in the hook 18 so that the jet of compressed air emitted therefrom will impinge upon the same porion of the surface to be painted as the spray of atomized paint from the spray nozzle, when the gun is held in the normal position for spray painting.

A valve 180 is positioned within cavity 150 to control the flow of compressed air from the cavity 150 through counter bore 172, passage 174, annular space 124, passage 176 and the dusting nozzle 178. As shown in FIG- URES l-'3, the other end of the coil spring 171 abuts the valve 18!) whereby the spring performs the dual function of biasing the valve element 126 to the left while biasing the valve member 180 to the right. Valve 180 may be moved to the left and thus opened by the operator depressing a button 182 which is rigidly connected to the valve 180 and which fits within counter bore 172.

As noted above, the stud 169 extends to the right from land 166 a certain distance toward valve 180. The length of this stud is such that when the valve 180 is opened by depressing the button 182 or when the valve element 126 is moved to the right by depressing the trigger 14, the right end of the stud and the valve 180 abut. Thus the stud acts as an interlock or stop in that it prevents the valve 180 from being opened whenever the valve element 126 is in the position shown in FIGURE 2, viz. when passage 152 is in communication with chamber 82. Conversely, whenever the valve 180 is open, thereby permitting communication between passage 152 and the dusting nozzle 178, the stud prevents the operator from pulling back the trigger and shifting the valve element 126 from the position shown in FIGURE 3 to the position shown in FIGURE 2, viz., prevents the operator from spraying paint through the spray nozzle assembly 16.

Thus, by correctly selecting the length of stud 169, it is apparent that the simultaneous emission of a jet of compressed air from dusting nozzle 178 and a jet of atomized paint from the spray nozzle is not possible.

The operation of this novel spray gun may be summarized by referring to FIGURES 1-3. When the spray gun is not being utilized, the valve assembly 46, including the fluid motor in chamber 82, the pilot valve 96 and the valve 180 are in the positions shown in FIGURE 1 wherein the chamber 82, to the left of piston 84, is vented to the atmosphere while intercommunication between the compressed air in passage 152 and chamber 82 and the dusting nozzle 178 is blocked by the pilot valve 126 and valve 180, respectively. As shown in FIG- URE 2, when the operator pulls back the trigger 14, the pilot valve 126 is moved to the right so that communication between the compressed air in passage 152 and the chamber 82 is established whereby the valve assembly 46 is caused to move away from the seat 39, as shown in FIGURE 4, and paint or like materials may pass through the nozzle and be hydraulically atomized. The dusting nozzle 178 may be utilized to clean foreign particles from a surface to be spray painted by simply depressing the valve button 182 and thus opening the valve 180, as shown in FIGURE 3, whereby compressed air in passage 152 may flow through passage 174, space 124, passage 176 and be sprayed from. the nozzle 178. As shown in FIGURES 2 and 3, the arrangement of the valves 126 and 180 and the length of the stud 169 positioned therebetween are such that the trigger l4 and the valve button 182 cannot be simultaneously depressed.

In view of the foregoing, it is apparent that the above described spray gun is a commercially significant improvement in that it not only provides superior airless spraying but also incorporates therein a dusting nozzle which may be utilized to clean the surface to be painted prior to painting. The incorporation of the dusting nozzle in the spray gun considerably simplifies the problem of cleaning the surfaces to be painted and concomitantly reduces the time needed for the pre-cleaning of the surfaces thereby significantly increasing the efficiency and productivity of the painter.

Furthermore, the novel spray gun of the present invention utilizes compressed air from the same source to control both the flow of pressurized paint through the spray nozzle and to pre-clean the surface to be painted, thereby greatly simplifying the operation of the gun and minimizing the external connections required therefor.

Moreover, through the unique cooperation between the valves controlling the flow through the dusting nozzle and the valve controlled by the trigger, simultaneous flow through the dusting nozzle and the spray nozzle is prevented, thereby eliminating the possibility of an accidental simultaneous discharge through both of these nozzles.

While I have shown certain specific embodiments of my invention for purposes of illustration, it is to be understood that the scope of my invention is limited solely by the appended claims.

I claim as my invention:

1. An airless spraying apparatus for coating materials, comprising: a body having first and second chambers formed therein; first nozzle means mounted on said body; means for supplying a coating material under pres sure to said first nozzle means; first valve means for controlling the flow of coating material through said first nozzle means thereby permitting said material to be sprayed onto a surface to be coated; said first valve means including fluid pressure responsive means positioned within said first chamber; means for supplying a fluid under pressure to said second chamber; second valve means for permitting controlled communication between said second and first chambers; second nozzle means mounted on said body; and means for permitting communication between said second chamber and said second nozzle means including a third valve means for controlling the flow of said pressurized fluid through said second nozzle means.

2. An airless spraying apparatus for coating materials comprising: a body having first and second chambers formed therein; first nozzle means mounted on said body; means for supplying a coating material under pressure to said first nozzle means; first valve means for controlling the flow of coating material through said first nozzle means thereby permitting said material to be sprayed onto a surface to be coated; fluid pressure responsive means positioned within said first chamber and operatively connected with said first valve means; means for supplying a fluid under pressure to said second chamber; second valve means for permitting controlled communication between said second and first chambers; second nozzle means mounted on said body; means for permitting communication between said second chamber and said second nozzle means including a third valve means for controlling the flow of said pressurized fluid through said second nozzle means for cleaning said surface; and means for preventing simultaneous flow through both said first and second nozzle means.

3. An airless spraying apparatus for coating materials comprising: a body having first and second chambers formed therein; first nozzle means mounted on said body; means for supplying a coating material under pressure to said first nozzle means; first valve means for controlling the flow of coating material through said first nozzle means thereby permitting said material to be sprayed onto a surface to be coated; fluid pressure responsive means positioned within said first chamber and operatively connected with said first valve means; means for supplying a fluid under pressure to said second chamber; second valve means for permitting controlled communication between said second and first chambers whereby said pressurized fluid causes said first valve means to move to permit flow through said first nozzle means; second nozzle means mounted on said body; means for permitting communication between said second chamber and said second nozzle means including a third valve means for controlling the flow of said pressurized fluid through said second nozzle means for cleaning said surface; and means cooperating with said second and third valve means for preventing simultaneous flow through both said first and second nozzle means.

4. An airless spraying apparatus for coating materials comprising: a body having first and second chambers formed therein; first nozzle means mounted on said body; means for supplying a coating material under pressure to said first nozzle means; first valve means for controlling the flow of coating material through said first nozzle means thereby permitting said material to be sprayed onto a surface to be coated; fluid pressure responsive means positioned within said first chamber and operatively connected withsaid first valve means; means for supplying fluid under pressure to said second chamber; second valve means for permitting controlled communication between said second and first chambers; second nozzle means mounted on said body, said second nozzle means being directed in the same direction as said first nozzle means whereby spray emitted from said first and second nozzle means impinges against substantially the same portion of the surface to be coated; means for permitting communication between said second chamber and said second nozzle means including a third valve means for controlling the flow of said second pressurized fluid through said second nozzle means for cleaning said surface; and means for preventing simultaneous flow through bot-h said first and second nozzle means.

5. An airless spray gun for liquid coating materials comprising: a body having first, second, third and fourth chambers formed therein; means for supplying pressurized coating material to said first chamber, a first nozzle mounted on said body in communication with said first chamber and having an orifice through which said material may pass, thereby atomizing said material and directing the same onto a surface to be coated; a first valve means for controlling the flow through said orifice; a fluid presure responsive mot-or means movable within said second chamber and operatively connected with said first valve means, whereby said motor means may move said first valve means between a closed position and an open position in which said material may pass through said orifice; means for supplying a pressurized gas to said third chamber; means for exhausting said fourth chamber; second valve means movable between a first position wherein said second chamber is in communication with said third chamber whereby said motor means moves said first valve means to an open position and a second position wherein said second chamber is in communica tion with said fourth chamber whereby said motor means moves said first valve means to said closed position; a second nozzle mounted on said body; conduit means connecting said third chamber with said second nozzle and thirdvalve means for controlling the flow of pressurized gas from said third chamber through said second nozzle.

6. An airless spray gun for liquid coating materials comprsing: a body having first, second, third and fourth chambers formed therein; means for supplying pressurized coating material to said first chamber; a first nozzle mounted on said body in communication with said first chamber and having an orifice through which said material may pass, thereby atomizing said material and directing the same onto a surface to be coated; a first valve means for controlling the flow through said orifice; a fluid pressure responsive motor means movable within said second chamber and connected to said first valve means whereby said motor means may move said first valve means between a closed position and an open position in which said material may pass through said orifice; means for supplying compressed air to said third chamber; means for exhaustnig said fourth chamber; second valve means movable between a first position wherein said second chamber is in communication with said third chamber whereby said motor means moves said first valve means to an open position and a second position wherein said second chamber is in communication with said fourth chamber whereby said motor means moves said first valve means to the closed position; a second nozzle mounted on said body; conduit means connecting said third chamber with said second nozzle; third valve means for controlling the flow of compressed air from said third chamber through said second nozzle for cleaning said surface and means for preventing simultaneous flow through both said orifice and said second nozzle.

7. A spray gun, as described in claim 6 wherein said first and second nozzles are pointed in substantially the same direction whereby flow through both said first and second nozzles may be directed onto substantially the same portion of said surface.

a 8. An airless spray gun for liquid coating materials comprising: a body having first, second, third and fourth chambers formed therein; means for supplying pressurized coating material to said first chamber; a first nozzle mounted on said body in communication with said first chamber and having an orifice through which said material may pass, thereby atomizing said material and directing the same onto a surface to be coated; a first valve means for controlling the flow through said orifice; a fluid pressure responsive motor means movable within said second chamber and connected with said first valve means whereby said motor means may move said first valve means between a closed position and an open position in which said material may pass through said orifice; means for supplying pressurized gas to said third chamber; means for exhausting said fourth chamber; second valve means movable between a first position wherein said second chamber is in communication with said third chamber whereby said motor means moves said first valve means to an open position and a second position wherein said second chamber is in communication with said fourth chamber whereby said motor means moves said first valve means to the closed position; a second nozzle mounted on said body; conduit means connecting said second nozzle with said third chamber, third valve means for controlling the flow of pressurized gas from said third chamber through said second nozzle and means positioned between and cooperating with said second and third valve means for preventing simultaneous flow through both said orifice and said second nozzle.

9. An airless spray gun for liquid coating material comprising: a body having first, second, third and fourth chambers formed therein; means for supplying pressurized coating material to said first chamber; a first nozzle mounted on said body in communication with said first chamber and having an orifice through which said material may pass, thereby atomizing said material and directing the same onto a surface to be coated; a first valve means for controlling the flow through said orifice; a fluid pressure responsive motor means movable within said second chamber and connected with said first valve means whereby said motor means may move said first valve means between a closed position and an open position in which said material may pass through said orifice; means for supplying pressurized gas to said third chamber; means for exhausting said fourth chamber; sec-0nd valve means movable between a first position wherein said second chamber is in communication with said third chamber whereby said motor means moves said first valve means to an open position and a second position wherein said second chamber is in communication with said fourth chamber whereby said motor means moves said first valve means to the closed position; a second nozzle mounted on said body; conduit means connecting said third chamber with said second nozzle; third valve means for controlling the flow of pressurized gas from said third chamber through said second nozzle and means carried by said second valve means and arranged to cooperate with said third valve means whereby when said second valve means is in said first position, said third valve means is prevented from permitting flow through said second nozzle and whereby when said third valve means is opened to permit flow through said second nozzle, said second valve means is prevented from being moved from said second to said first position.

10. An airless spray gun for spraying liquid onto a remote surface comprising: a body; a first nozzle mounted on said body; means for supplying pressurized coating material to said first nozzle whereby said material may flow through said first nozzle and be sprayed onto a surface to be coated; first valve means adjustably movable for controlling the flow of coating material through said first nozzle; a pressure responsive motor means mounted in said body and operatively connected with said first valve means for positioning said first valve means; means for supplying pressurized gas to said body; means for exhausting said gas from said body, second valve means including a piston mounted in said body and selectively movable between a first position, wherein said gas supply means is interconnected with motor means thereby causing said motor means to move said first valve means so that said material may flow through said first nozzle and a second position wherein said gas exhausting means is interconnected with said motor means thereby causing said motor means to move said first valve means so that said material is prevented from flowing through said first nozzle; means for biasing said piston to said first position; manually operated trigger means for moving said piston from said first position to said second position; a second nozzle mounted in said body; a passage connecting said gas supply means with said second nozzle whereby said gas may flow through said second nozzle and be sprayed onto said surface for cleaning the same; and third valve means including a normally closed valve member selectively movable in said body from an open position wherein communication is permitted between said gas supply means and said second nozzle and a closed position wherein communication is prevented between said gas supply means and said second nozzle.

11. A spray gun, as described in claim 10, wherein said first and second nozzles are pointed in substantially the same direction whereby flow through both said first and second nozzles may be directed onto substantially the same portion of said surface.

12. An airless spray gun for spraying liquid onto a remote surface comprising: a body; a first nozzle mounted on said body; means for supplying pressurized coating material to said first nozzle whereby said material may flow through said first nozzle and be sprayed onto a surface to be coated; first valve means adjustably movable for controlling the flow of coating material through said first nozzle; a pressure responsive motor means mounted in said body and operatively connected with said first valve means for positioning said first valve means; means for supplying pressurized gas to said body; means for exhausting said gas from said body, second valve means including a piston mounted in said body and selectively movable between a first position, wherein said gas supply means is interconnected with motor means thereby causing said motor means to move said first valve means so that said material may flow through said first nozzle and a second position wherein said gas exhausting means is interconnected with said motor means thereby causing said motor means to move said first valve means so that said material is prevented from flowing through said first nozzle; means for biasing said piston to said first position, manually operated trigger means for moving said piston from said first position to said second position; a second nozzle mounted in said body; a passage connecting said gas supply means with said second nozzle whereby said gas may flow through said second nozzle and be sprayed onto said surface for cleaning the same; third valve means including a normally closed valve member selectively movable in said body from an open position wherein communication is permitted between said gas supply means and said second nozzle and a closed position wherein communication is prevented between said gas supply means and said second nozzle; and means for preventing the opening of said valve member whenever said piston is in said second position and preventing said piston from being moved from said first position to said second position, whenever said valve member is in its open position.

13. An airless spray gun for spraying liquid onto a remote surface comprising: a body; a first nozzle mounted on said body; means for supplying pressurized coating material to said first nozzle whereby said material may flow through said first nozzle and be sprayed onto a surface to be coated; first valve means adjustably movable for controlling the flow of coating material through said first nozzle; a pressure responsive motor means mounted in said body and operatively connected with said first valve means for positioning said first valve means; means for supplying compressed air to said body; means for exhausting said compressed air from said body, second valve means including a piston mounted in said body and selectively movable between a first position, wherein said air supply means is interconnected with motor means thereby causing said motor means to move said first valve means so that said material may flow through said first nozzle and a second position wherein said air exhausting means is interconnected with said motor means thereby causing said motor means to move said first valve means so that said material is prevented from flowing through said first nozzle; means biasing said piston to said first position; manually operated trigger means for moving said piston from said first position to said second position; a second nozzle mounted in said body; a passage connecting said air supply means with said second nozzle whereby said compressed air may flow through said second nozzle and be sprayed onto said surface for cleaning the same; third valve means including a normally closed valve member selectively movable in said body from an open position wherein communication is permitted between said air supply means and said second nozzle and a closed position wherein communication is prevented between said air supply means and said second nozzle, said valve member being positioned coaxially with said piston; resilient biasing means positioned between said piston and said valve member for urging said piston to said first position and said valve member to its closed position; said piston having a portion projecting therefrom toward said valve member and arranged so that saidpiston cannot be moved from said first position tosaid second position whenever said valve member is in its open position.

14. A spray gun as described in claim 13 wherein said valve member may be moved from its closed position to its open position by manually movable means separate from said trigger means and wherein an elongated shaft interconnects said first valve means with said motor means the axis of said shaft being coaxial with the longitudinal axis of said first nozzle means.

15. A spray gun as described in claim 13 wherein said body includes a hook-like portion formed integrally therewith, and said second nozzle is mounted in said hook-like portion.

16. A spray gun, as described in claim 13, wherein said first and second nozzles are pointed in substantially the same direction whereby flow through both said first and second nozzles may be directed onto substantially the same portion of said surface.

No references cited.

EVERETT W. KIRBY, Primary Examiner.

Non-Patent Citations
Reference
1 *None
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3653592 *May 7, 1970Apr 4, 1972ElectrogasdynamicsElectrostatic spray gun construction
US4005825 *Nov 24, 1975Feb 1, 1977Ford Motor CompanyMixing manifold for air atomizing spray apparatus
US5284299 *Aug 24, 1992Feb 8, 1994Ransburg CorporationPressure compensated HVLP spray gun
US5330108 *Apr 28, 1993Jul 19, 1994Ransburg CorporationSpray gun having both mechanical and pneumatic valve actuation
US5460203 *Jan 12, 1993Oct 24, 1995Itw LimitedAir valve
US7740192 *Jun 28, 2006Jun 22, 2010Kuo-Liang ChenRotating bi-directional pneumatic gun
US7950598Dec 30, 2008May 31, 2011Graco Minnesota Inc.Integrated flow control assembly for air-assisted spray gun
US7971806Dec 30, 2008Jul 5, 2011Graco Minnesota Inc.Poppet check valve for air-assisted spray gun
US8651397Mar 5, 2010Feb 18, 2014Techtronic Power Tools Technology LimitedPaint sprayer
DE2209896A1 *Mar 1, 1972Sep 7, 1972 Title not available
Classifications
U.S. Classification239/412, 239/417.5, 239/416.2, 239/569, 239/413, 239/418, 239/443
International ClassificationB05B1/30, B05B9/00, B05B15/00, B05B9/01
Cooperative ClassificationB05B1/306, B05B15/00, B05B9/01, B05B12/002
European ClassificationB05B12/00M, B05B15/00, B05B9/01, B05B1/30D1A4