US1876644A - Device for spraying paints, lacquers or other liquids - Google Patents

Description

A. H. DOWNS Sept; 13, 1932.

DEVICE FOR SPRAYING PAINTS, LACQUERS, OR OTHER LIQUIDS Original Filed Aug- 2. 1926 2 Sheets-Sheet 2 I 7V1 01 h W5 6 V I 9 m a w 7 Patented Sept. 13, 1932 UNITED STATES PATENT OFFICE AUSTIN H. DOWNS, OF NEWARK, NEW JERSEY, ASSIGNOR TO ECLIPSE AIR, BRUSH- COM- IPANY, INC., 01 NEWARK, NEW JERSEY, A CORPORATION OF NEW JERSEY DEVICE FOR SPBAYING PAINTS, LACQUEBS OR OTHER LIQUIDS Original application filed August 2,

1926, Serial No. 126,507. Divided and this application filed June 28,

1928. Serial No. 288,986.

This invention relates to improvements in devices for spraying paints, lacquers or other liquids as well as heavy liquids, semi-pastes, etc. and the principal object is the provision of such a device which is highly eflicient in operation, simple and readily controlled to use a minimum amount of material and a minimum amount of pressure to accomplish the best results.

Further objects include the provision of such a device in which the trigger control is very accurate and simple, which operates at low air pressures and volumes and with a low consumption of material, thereby reducing the amount of mists and fumes to a minimum and still aflording perfect atomization of the material and application thereof to the surface being coated.

Another object of this invention is the provision of such a device in which the entire body and handle are made of one piece preferab'ly by die-casting or forging, whereby the manufacture of the same is simplified and eheapened and at the same time a more at tractive appearing and substantial device is provided.

Further objects include improvements in details of construction and which are hereinafter set forth in full.

To the accomplishment of the foregoing and such other objects as may hereinafter appear, this invention consists in the construction, combination and arrangement of parts hereinafter described and then sought to be defined in the appended claims, reference being had to the accompanying drawings forming a part hereof and which show, merely for the purpose of illustrative disclosure, a preferred embodiment of my invention, it being expressly understood, however, that various changes may be made in practice within the scope of the claims without digressing from my inventive idea.

In the drawings- Figure 1 represents a vertical longitudinal cross section through a device constructed to embody my invention shown in inoperative or closed condition infull lines, the open position of the trigger being indicated in dotted lines.

Figure 2 is a side elevation of a device constructed to embody my invention shown with one form of connection to a pressure feed cup.

Figure 3 is a vertical cross section through another form of connection between the device itself and a pressure feed cup.

t Figure 4 is a perspective view of the fluid Figure 5 is a view similar to Figure 1, showing a slightly modified construction, particularly with reference to the nozzle and fluid tipand also the air valve and its operating connections.

Figure 6 is a longitudinal section on an enlarged scale of the nozzle and fluid tip construction shown in Figure 5.

Figure 7 is a front end elevation of the device shown in Figure 5 with the nozzle removed.

Fi ure 8 is a vertical cross section showing the uid tip in elevation.

Fig. 9 is a top plan view of the yoke member with its bearing rods, the yoke member being used to actuate'the liquid valve.

This application i sfiled as a division of my pending application Serial No. 126,507, filed August 2, 1926. 7

Referring now to the. drawings, the numeral 1 designates the body of the device as a whole, this body including the barrel portion 2 and the handle portion 3, the handle portion extending downwardly from the barrel portion, and inclined slightly to the rear so that the device has somewhat the appearance of an automatic revolver.

Devices of this kind are employed to spray material principally for coating purposes, the material being atomized by air under pressure. The material is fed to the point of atomization by pressure and consequently this device has ports, passages and valves for controlling the admission and passage of the pressure fluid as well as the liquid material and the atomization of the same. A connection 4 to a suitable source of air or other fluid under pressure is made with the screwthreaded nipple 5 on the lower end of the handle portion 3. Usually this pressure is automatically maintained by suitable regulating means as is well understood. This nipple leads to the passage 6 which extends upwardly through the interior of the handle 3 to the air inlet valve chamber 7. This valve chamber is provided with a bevelled valve seat 8 leading to the passage 9 which communicates with an upwardly extendi ng passage 10, which in turn communlcates with the horizontally extending passage 11 located in the barrel 2. Mounted in the valve chamber 7 is a suitable valve member 12 having the valve proper 13 adapted to engage the seat 8 and having the operatin stem 14 extending forwardly therefrom, an through a suitable bushing 15 to extend without the body, as shown, to bear against a trigger to be presently described. The rear end of the valve member 12 is provided with the stud or projection 16 to receive one end of the coil spring 17, the other end of which is positioned in a socket 18 in the securing and tension adjusting nut 19, which is screwed into the rear end of the valve chamber 7. By this means the valve 13 isnormally held in tight engagement with its seat 8 so that no air pressure is admitted through the passages 6, 7, ,9, 10 and 11 unless the valve is opened.

It is to be noted that in the passage 6 I provide a downwardly extending bypass or passage 20 which is provided with a valve seat 21 adapted to receive a valve 22, shown in the form of a ball, which valve is normally held in engagement with its seat by means of coil spring 23-, which is held in position and under tension by means of a screw-threaded adjusting nut 24. This nut is provided with opening or aperture 25 therethrough, which has its outlet arranged in a downwardly extending position. The purpose of this lastdescribed feature is to provide a signal for the operator so that if the fluid pressure hecomes sufficiently great to overcome the regu-' lar tension of the coil spring 23, a jet of air will be emitted from the opening 25 and impin e against .the hand or arm of the sleeve of t e operator, giving him a signal, whereby he can adjust the pressure producing mechanism and take whatever precautions are necessary to prevent the dangerous increase in pressure which is likely to result in damage and injury to the mechanism, and also waste material as well as give unsatisfactory results. While this signal is in the form of one which affects the sense of touch or feeling, it is obvious that it can be made an audible signal in the form of a whistle.

The. trig er above referred to is designated by the ref arence character 26 and has the downwardly extending portion 27 adapted to be engaged by certain fingers of the hand of .the operator, the upper portion of the trigger being of yoke construction 28 and pivoted as at 29 on both sides of the barrel, the latter being cut out as at 30 to receive the yoke portion 29 of the trigger (see Figure 2 particularly The trigger is provided with a hearing ace 31 on the rear side Which engages the front end of the valve stem 14 and when the trig er is forced rearwardly the valve stem an its attached valve are forced rearwardly and the valve forced off its seat to permit the admission of air through passages previously mentioned. The rearward movement of the trigger is limited by means of the stop or abutment 32 coming into contact with a portion of the body. Spring 17 is of sufiicient strength to normally hold the valve closed and the trigger in its extended open position shown in full lines in Figure 1 of the drawings, and to cause these parts to assume these positions when the pressure is released from the trigger and to cause these parts to move from these positions when the pressure on the trigger is reduced. Thereby a very simple and delicate control is provided for controlling the admission of air into the device and it is very easily regulated by an operator and without the necessity of long training and experience.

The barrel portion 2 extends in a horizontal direction forwardly from the handle portion 3 and is provided with the apertured lug or flange 33 to provide a convenient hanging means. The barrel is bored centrally to provide the packing gland and spring chamber 34 in its rear end portion. This chamber receives the packing gland which is in the form of an elongated sleeve 35 having an externally screw-threaded portion 36 to engage the internal threads formed in the rear part of the pacln'ng gland chamber. Sleeve 35 has the headed nut portion 37 whereby the packing gland may be screwed into the chamber 34 and its position therein adjusted. The valve rod 38 which controls the'supply of H uid material, extends through and is mova ly mounted within the bore in the bar- -rel and its rear portion passes through the packing gland chamber 34, the packing gland 35 and an opening 39 in the head 37 of the packing gland. A washer 40 is secured to this valve rod 38 within the packing gland and a compression spring '41 is positioned around that portion of the rod within the packing gland 35 between the washer 40 and the head 37, this spring being placed under regulated tension by an adjustment of the packing gland 35. That part of the chamber 34 which is shown to the left of the packing gland 35 is filled with a suitable packing material so as to make the joint between the valve rod 38 and the body fluid tight.

This valve rod, as stated above, extends through the opening 39 in'the head 37 of the packing gland and is provided at its end with the screw-threaded portion 42 to receive the adjusting nut 43 and locking nut 44. The valve rod 38 is moved by means of the yoke member 45 whichhas an engaging member tens on 62 of the barrel.

46 provided with a slot 47 to slidably receive the rear portion of the valve rod 38. This yoke member has each of its two arms 48 connected to a bearing rod 49 slidably mounted in a bearing passage 50 formed in one side of the body. The forward ends of these bearing rods 49 extends beyond the ends of the bearing passages 50 into the path of movement of the upper and yoke portion 28 of the trigger member 26, so that when the trigger member is moved a suflicient distance to the rear, the bearing rods 49 will be moved 'rearwardly and due to the engagement of the yoke member 45 with the nuts 43 and44, the valve rod 38 will be moved rearwardly to open the valve to be presently described. It is to be expressly noted at this point that it is impossible to adjust those parts so that the valve rod 38 can be moved prior to the opening of the air valve 13. In other words, the initial movement of the trigger opens the air valve 1?) and permits a supply of air under pressure to enter .thedevice before the alve member 38 can be moved. It is also to be noted that in the position shown in full lines in Figure 1, the packing material in the packing gland is subject to the greatest pressure from the washer 40, that is when the valve rod 38 is in its closed position, and as the valve rod 38 is moved to open the same the pressure on the packing material lessens.

The forward end of the valve rod 38 is made in the form of a head 51 which has the blunt end 52 and the curved rear shoulder 53 leading to the reduced portion 54, which extends to the shoulder 55, which. forms the reduced portion 54 from the valve rod as a whole. This part of the valve rod just described is mounted in the liquid material receiving chamber 56 which is formed in the front end of the barrel portion and communicates with the material supply passage 57 which extends vertically through the downward extension 58, this downward extension 58 having its lower portion screw-threaded as at 59 to afford a connection for a hose or pipe leading from a suitable liquid conta ner or to the material cup to be presently described. Surrounding the upper portion of this extension 58 is the vertical annular air passage 60 which connects with horizontal passage 11 and also with a horizontal annular air passage 61 formed in a forward ex- This forward extension is screw-threaded on its outside as at 63 to receive the nozzle 64. This forward extension is also provided with the internal screw-thread 65 to receive the fluid tip 66.

This fluid tip is shown indetail in Figure 4 and is provided with the screw-threaded extension 67 whereby it is secured in position engaging the screw-threads 65 of the forward extension 62. It has the flange 68 which is provided with a plurality of slots or apertures 69, this flange tightly fitting within the end of the extension 62 and affording a closure for the horizontal annular air passage 61, it being noted that the end of the extension 62 is beyond the end of the inner wall and that the face of the disc 68 fits against the end of the inner wall. The outer face of the flange 68 is flush with the outer end of the forward extension 62, and the slots or openings 69, therefore, afford means of egress for the air from the horizontal annular air passage 61. This construction gives a very even distribution of air which is an important factor in the successful operation of this device. This fluid tip 66 is provided with the squared shoulder 69 and then with the tapered portion 70, this'taper being formed on a curve as shown and terminating in a shoulder 71 from which the tip portion 72 extends, this tip portion being of cylindrical or tubular shape. The fluid tip is bored entirely therethrough, the bore 73 through the forward portion being less in diameter than the bore 7 4 through the rear portion. The rear end of the fluid tip where the bore 74 opens forms a seat 7 5 for the valve 51 on the end of the valve rod 38. It is seen, therefore, that the fluid material passes up through passage 57 into the chamber 56, and when the valve 51 is moved off its seat the material will pass through bores 74 and 73 and emerge from the end of the fluid tip.

The nozzle 64 is shown in Figures 1 and 2 and in detail in Figure 8 of the drawings. This nozzle which I term a fan slot nozzle is of general cylindrical form, being substantially hollow for attachment to the external screwhreaded portion 63 of the barrel above referred to and has the conical shaped passage 76 extending therethrough and leading to a cylindrical passage 77. This cylindrical passage leads into a flat fan shaped or arcuate slot 78. The cylindrical tip 72 of the fluid tip is positioned within the cylindrical passage 77 of the nozzle. The junction of the cylindrical passage with the conical passage 76 in the nozzle aifords an annular shoulder or seat 79 with which the tapered portion 70.

of the fluid tip may come into engagement when the nozzle is turned or screwed upon the barrel a sufficient extent. By this means the air may be shut oil entirely or the flow adjusted so as to govern the atomization of the liquid. It is to be noted that the cylindrical passage 77 in the nozzle extends in the nozzle body beyond the innermost edge of the fan slot and as the slot is less in width than the diameter of passage 77, shoulders 7 9 are formed and these shoulders assist in breaking up the liquid by diverting the direction of flow of the air and causing the air to undergo a sharp change of direction and pass into and across the stream of liquid from the fluid tip. This passage 77 is located centrally with respect to the slot. The abrupt changing of the direction of flow of the air across the stream of liquid as it emerges from the fluid tip, results in complete breaking up and atomization of theliquid, and its discharge in the form of a finely divided spray of uniform 'density. This action also retards the direct flow of liquid from the nozzle which would result in an uneven spray of non-uniform density. In other words, the liquid is forced through the fluid tip under pressure and would pass through the nozzle in the form of a thin narrow thick stream, but the air being directed by the shoulders 79 across the stream of liquid retards the flow of the same through the nozzle, breaks it up into small particles and prevents its passage through the nozzle as a stream of liquid. This retarding action due to what might be termed eddy currents of air, is very important and gives the advantageous results hereinbefore referred to. It makes the use of a pressure feed cup possible in a device of this character and still give eificient results in the application of these materials.

Referring now to Figure 2 the numeral 80 designates a cup or other receptacle which is adapted to receive a suitable supply of fluid material to be sprayed. This cup has a cap or top member 81 having the projection 82 adapted to be secured to the downward extension 58 of the gun. It is to be noted that the vertical annular air passage of the gun is closed by means of suitable washers 83 and nut 84 (Figure 1). In order to provide pressure in the cup for forcing the fluid material from the cup, an air bypass pipe or tube 85 is connected to the side of the barrel so as to communicate with the vertical annular air passage 60. This bypass extends downwardl as shown in Figure 2, and passes through the top or capof the cup as at 86. Therefore, when air under pressure is admitted to the vertical annular passage 60, it is also admitted into the fluid cup or container by means of the bypass whereby the material therein is subjected to pressure and will be forced out through the connection 82 and the liquid passage 57 into the liquid chamber 56. Then when the liquid valve 51 is moved off its seat the liquid under pressure will pass through passages 74 and 73 and be discharged from the tip 72 of the fluid tip 66.

When the device is used in connection with pressure. tanks, which are usually separate and positioned at a distance from the gun or liquid applying instrument, the air bypass 85' is closed or shut off and fluid pres- ,sure is applied to the pressure tank from the source of pressure. A connection is made from the extension 58 of the air gun or spraying device to the fluid container or tank so that the liquid therein when subjected to pressure will be forced up to the liquid chamber 56 and discharged from the fluid tip and vertical passage 60,

nozzle when the valve 52 is moved off of its seat, as is well understood in the art.

In Figure 3 of the drawings I show a detail of a modified form of connection between the gun and the fluid cup. This includes the top or cap 87 adapted to be suitably secured to the cup by clamping or other means, and having an extension in the form of tube 88, which is adapted to'be secured to the downward extension 58 of the device by means of a screw threaded connection. As the downward extension 58 has the external screwthreads' 59, the extension or tube 88 is provided with complementary internal screwthreads 88'. These screw-threads terminate short of the top end of the tube or extension 88, as shown in Figure 3, leaving a shoulder 88". The upper edge of this tube or extension 88 is adapted to engage an annular face formed by the lower edge 60' on the gun located about the annular air passage 60. This shoulder 88" provides a space to receive washerslike 83, and, in the event such washers are used, they will fit the outside of the extension 58 loosely, leaving sufficient space so as to permit the passage of fluid under pressure between the washers and the exterior surface of the extension 58. This'tube or extension 88 is formed of substantially thick material, having the bore or passage 89 formed therein. Leading into this passage 89 are aplurality of smaller passages 90 which are adapted to communicate with the vertical annular air passage 60 in the downward extension 58. Of course, when this construction is attached, nut 84 is removed from extension 58. The small vertical passages 90 are preferably formed in the thickened portion of the tube or extension 88 in which the internal screw-threads 88 are formed. Nut member 91 having a bore 92 is screwed into the cap 87 from its underside closing the passage or bore 89 and forming a bushmg to receive and guide the liquid post or tube 93. This post or tube 93 has its upper end externally screw-threaded as at 94.- for attachment to the internal screw thread 95 formed in the liquid passage through the extension 58. This liquid post 93 extends downwardly to a point near the bottomof the cup or receptacle 80. The cap is bored from the inside, as at 96 to provide passages or ports leading from the bore or passage 89 to the inside of the cap and into the container whereby the liquid therein is subjected to air pressure from the air passa 'es'when the air valve 13 is open.

operation, it being understood that the fluid cup is connected to extension 58 and that a source of air pressure is connected to extension 5, the operator presses the trigger 26- which immediately opens air valve 13 whereby a supply of air under pressure is admitted through passages 10 and 11, the ypass 85, (or in the form shown in Figure 4, passages 90, 89 and 96), into the cup 80. This air under pressure also passes through the horizontal annular passage 61 into the nozzle, in the space between the nozzle and the fluid tip and passes from the nozzle through the fan slot. Due to the fact that the valve rod 38 has not as yet been moved, there is no passage of paint or other liquid and this does not occur until air under pressure is flowing through the nozzle. Fur-. ther movement of the trigger results in a movement of the valve rod 38, which moves the valve 51 from its seat in the rearend of the fluid tip and permits the liquid which, due to the air pressure thereon in the cup, has been forced up through passage 57 into the chamber 56, to pass through the bores 74 V and 73 in the fluid tip into the cylindrical There the fluid meets the outrushing current of air under pressure and is completely broken up and atomized and forced out of the fan slot passa e opening in the form of a sheet of misty uid material in proper shape to coat the surface. When the pressure is relieved from the trigger the liquid valve 51 first seats, closing the liquid passages and preventing the material dripping or otherwise discharging from the nozzle. As the air valve is still open, air under pressure will be discharged through the nozzle and clean the same of all of the liquid material there present. After this liquid valve has seated, the air valve seats, disconnecting the parts of the apparatus from the source of air pressure. Then the air pressure on the cup or container exhausts into the atmosphere through the bypass, vertical annular passage 60, horizontal annular passage 61 and the nozzle, so that the fluid cup is relieved of pressure and the parts assume a normal condition. This action of exhausting the air from the fluid cup and the passage of air through the device after the fluid valve is seated, results in a thorough cleaning of the valve parts, preventing waste of material and the very objectionable dripping feature, and also relieves the container from all pressure when the device and apparatus are not in use.

The construction shown in Figure 5 of the drawings operates in the same manner as the construction previously described. In that view, however, the air valve member 12' is mounted to move horizontally in the barrel portion 2 of the device and has the valve proper 13 formed at its end to rest against the seat 8' formed in the longitudinal air passage 11 in the barrel. The stem or plunger M of this valve extends through the bushing construction 15' beyond the rear end of the barrel and has a nut connection 97 with part of the yoke 45, whereby when the yoke bore 77 in the nozzle.

is moved the stem 15 and valve 13' are moved. 7

Spring 17 is positioned about the stem between the valve proper 13 and the bushing construction and normally tends to force and hold the valve in closed position. By this construction the movement of the air valve, as well as the liquid valve, is in a straight horizontal direction, which is an advantage in operation. The nut 97 constitutes an abutment with which the yoke 45 engages and these parts are 50 arranged that in the initial part of the movement of the trigger the air valve only will be opened and it is not until after this air valve is opened that the yoke 45 engages the abutment 43 to open the liquid valve. This relation of the parts is the same as in Figure 1.

-Referring now. to the nozzle or discharge end of the device shown in Figure'5 and also to detail views Figures 6 and 7, another form of nozzle construction will now be described. It includes the nozzle 64 having a tapered passage 76 leading to and communicating with a cylindrical passage 77 which in turn leads to and communicates with another cylindrical passage 77" which is of lesser diameter than the first-mentioned cylindrical passage 77'. This last-mentioned cylindrical passage 77 communicates with the flat fan shaped slot 7 8' formed in the end of the nozzle, this slot being less in width than the diameter of the cylindrical passage 77", whereby shoulders 7 9 are provided. These shoulders arepreferably straight, but may be slightly inclined as shown and are for the purpose of abruptly changing the direction of the current of air across the stream of liquid emerging from the fluid tip just as in the previous construction. The tapered passage 76" in the nozzle leads from'an air receiving compartment 98 formed'in the nozzle, as shown at the right in Figures 5 and 6. This compartment is of greater diameter than the larger end of passage 76, whereby an abrupt and substantial vided within the nozzle. The inner surfaces of this compartment and nozzle are not screw-threaded. The nozzle is provided with the end securing annular flange 100, which is engaged by an inwardly extending flange 101 on the locking ring 102, which is interiorly screw threaded as at 103 to engage the threads 63 formed on the outside of the forward extension 62 of the barrel.

The fluid tip itself includes the threaded extension 67 whereby it may be screwed into engagement with the internal screw-thread 65' of the forward extension 65",. The flat face or shoulder 67 of the fluid tip seats air-tight against the end of the forward extension 65". This fluid tip is provided with the squared or flat faced shoulder portion 69 with the tapered portion 70' extending forwardly therefrom to the cylindrical tip or projection 7 2', the tapered portion 7 0 terminating in the abrupt shoulder 71. The squared or flatrfaced portion 69' is provided with front shoulder 69". Both the tapered shoulder 99 is pro.'

portion 70' and the squared or fiat shaped rtion 69' are provided with a plurahty of ongitudinal extending slots or passages 67 these passages opening into the squared or flat faced portion 69 and extendlng throu h the tapered portion 7 0' so as to open into t e end of the tapered passage 76' 1n the nozzle. The fluid tip is bored as at 7 3' to permit the passage. of the liquid therethrough.

The fluid tip is mounted in position in the end of the liquid receiving chamber or com partment 56', the inner end of the bore 73' serving as a valve seat for the liquid valve 5 1. The nozzle 64 is positioned over the fluid tip and the shoulder 99 of the nozzle engages the shoulder 69 of the fluid tip, whereby the nozzle and the fluid tip are positioned relatively to each other. The nozzle is secured in position by means of a locking ring 102 previously described. This construction provides for a fixed adjustment and an adjustment which may always be obtained regardless of the number of times the nozzle and fluid tip are taken from the device or substitutions of these parts made. The liquid, of course, passes through the liquid passages and through the bore of the fluid tip when the liquid valve is open. The air under pressure passes through the air passages and through the plurality of small horizontal air ports or passages 61 which are formed in the end of the forward projection of the barrel and communicate with the vertical air passage therein. This air under pressure is admitted into the chamber 98 formed in the rear or inner end of the nozzle, and enters the ends of slots 69" passing through the tapered passage 76 and into the cylindrical passages 77 and 7 7 and in its passage therethrough is subjected to abrupt changes of direction, due to the shoulders 7 9" and 79". The position of the fluid tip with reference to these cylindrical passages and the shoulders and the fan slot is of utmost importance in securing perfect atomization and operation of this device. The arrangement of the slots 69" gives an even distribution of air throughout the confines of the nozzle.

It is to be noted that the nut 97 affords means for adjusting the position of the air valve 13' whereby the amount of air may be readily controlled. The fixed adjustment of the nozzle 64' is of material importance in making the device fool proof and in saving workmans time in attempting to secure proper adjustment. The action of the shoulders iii the two forms of nozzle in abruptly changing the direction of flow of the current of air causes eddy currents which gives a swirling action within the nozzle which results not only in complete atomization, but also in keeping the inside of the nozzle clean and free and prevents the same'from clogging and nevaeaa properly operating on that account, even with relatively thick materials.

This nozzle construction, as stated before, is readily adaptable to the pressure cup devices shown in Figures 2 and 3 of the drawings and enables the use of this form of device, even with ve heavy and thick materials. The inside mixed type of nozzle and the specific construction thereof permits the satisfactory use of the pressure cup.

While I have illustrated one form of nozzle, being what is termed a fan slot nozzle and also an inside mix nozzle, it is to be understood that various other forms of nozzles, such as conical nozzles and outside mix nozzles, may be used in connection with this construction.

Thisdevice results in a number of advantages, a few of which are as follows: a saving of a substantial percentage of the amount i5 and described only of material used, operation at greater speed, a

and operation on considerably less power. In addition, the device is composed of few wearing parts, being made strong and substantial and capable of maximum severe service. Mists, fumes and the chilling of the liquid material is minimized and a smooth, even flowing coat free from all blemishes is assured. The flow of liquid material is under perfect trigger control and the device is balanced, light in weight, convenient and easy to operate and unusually easy to clean.

What I claim is 1. In combination in a spray gun for atomizing and spraying liquids by means of air pressure having an air passage and a branch passage leading from said air passage, a valve in said branch passage, means for normally holding the valve on its seatto close said branch passage, said means being overcome by an excess of pressure to permit the discharge of air through said branch passage to give a signal.

2. In combination in a spray gun for atomizing and spraying liquids by means of air pressure having an air passage and a branch passage leading from said air passage, a valve in said branch passage, means for normally holding the valve on its seat to close said branch passage, said means being overcome by an excess of pressure to permit the discharge of air through said branch passage to give a si al by the stream of air impinging against t e person of the operator.

3. A paint spraying gun having a handle portion with an air passage therein, a branch passage connected to said air passage and having a valve seat therein, a valve in said branch passage, resilient means for normally holding the valve on its seat but releasable under excess pressure to permit the discharge of a current of air, and means for directing the current of air against the person of the operator.

4. In a device of the character described end to seat against said including, in combination, a body portion ha vinga plurality of passages to permit a sup ply of air therethrough to one end and also ha vine" passages to permit a supply of hquid theretln-ough to the same end of the body portion, an atomizing nozzle construction on said end of the body portion communicating with said passages, valve members for controlling the passage of liquid and the passage of air to said nozzle construction, means for opening said valves and a signal mechanism provided on said device in connection with said air passages to indicate excess pressure.

5. In a device of the character described including, in combination, a body portion having a passage to permit a supply of air therethrough to one end and also having a passage to permit a supply of liquid therethrough to the same end of the body portion, valve members for controlling the passage of liquid and the passage of air, means for opening said valves, and a signal mechanism provided in connection with said air passage, said signal mechanism including a passage directed toward a portion of the body of the operator and a valve in said passage normally closing the same but adjusted so as to be moved ofi its seat by an excess of pressure to permit the passage of air to give an indication or signal.

6. A device of the character described including, in combination, a body member having a handle portion and a barrel portion, air passages through the body member leading to the front end of the barrel portion, fluid passages in the body member leading to the front end of the barrel portion, a fluid tip communimting with said fluid passages and a nozzle communicating with said air passages and surrounding said fluid tip, a valve for controlling the passage of air through said air passages, a valve rod slidably mounted in said barrel portion and having a valve head on one fluid tip to control the pasage of fluid therethrough, said valve rod extending without the rear end of said barrel portion, resilient means for normally closing each of said valves, a trigger member pivotally connected to said body member, an abutment 011 said valve rod, a yoke member in engagement with said abutment and having a pair of guiding rods connected thereto and slidably mounted in said body portion, their ends being in the path of movement of said trigger, said trigger being adapted to open said air valve and then to engage said guiding rods to open said fluid valve.

'7. A device of the character described, including in combination, a body member having' air and liquid passages therein leading to one end thereof, a nozzle construction on said end for atomizing the liquid by air under pressure, a valve for controlling the air passage, another valve for controlling the liquid pressure,

passage, said liquid controlling valve having a stem projecting beyond the rear end of the body member and having an abutment member thereon, a yoke member adapted to engage said abutment and having a plurality of guiding rods connected thereto and slidably mounted in said body member, and means for operating said air valve and moving said rotlls so as to open said liquid controlling va ve.

8. A device of the character described, in-

cluding in combination, a body member having air and liquid passages therein leading to one end thereof, a nozzle construction on said end for atomizing the liquid by air under pressure, a valve for controlling the air passage, another valve for controlling the liquid passage, said liquid controlling valve having.

a stem projecting beyond the rear end of the body member and havlng an abutment member thereon, a yoke member adapted to engage said abutment and having a plurality of guiding rods connected thereto and slidably mounted in said body member, a trigger member pivoted to said body and having operative connection With said air valve to open it and also adapted to move said rods to open said liquid controlling valve.

9. A device of the character described, including in combination, a body member having air and liquid passages therein leading to one end thereof, a nozzle construction on said end for atomizing the liquid by air under pressure, a valve for controlling the air passage, another valve for controlling the liquid passage, said liquid controlling valve having a stem projecting beyond the rear end of the body member and having an abutment member thereon, a yoke member adapted to engage said abutment and having a plurality of guiding rods connected thereto and slidably mounted in said body member,a trigger member pivoted to said body and having operative connection with said air valve to open it and also adapted to move said rods to open said liquid controlling valve, and means for moving said valves to their closed position when pressure is released from said trigger.

10. A device ofthe character described, including in combination, a body member having air and liquid passages therein leading to one end thereof, a nozzle construction on said end for atomizing the liquid by air under a valve for controlling the air passage, another valve for controlling the liquid passage, each valve having a horizontally arranged stem, a trigger and a horizontally movable means connecting said stems, said means including a plurality of rods movable in said body on opposite sides thereof.

11. A device of the character described, in- I "said end for atomizing the liquid by air under connection including a plurality of rods v movable in said bodyon opposite sides thereof, said trigger having a yoke portion to engage the ends of said rods.

12. A device of the character descrlbed, 1n-

cluding in combination, a body member having air and liquid passages therein leading to one end thereof, a nozzle construction on said end for atomizing the liquid by air under pressure, a valve for controlling the air pa ssage, another valve for controlling the liquid passage, said liquid controlling Valve having a stem projecting beyond the rear end of the body member and having an abutment member thereon, a yoke member adapted to engage said abutment and having a plurality of guiding rods connected thereto and slldably mounted in said body member, and means for operating said air valve and moving said rods so as to open said liquid controlling valve, a pressure material cup having a connection with said liquid passage, a bypass between said air passage and said cup where by air pressure is admitted to the cup when the air valve is opened and material forced through said connection and liquid passage when the liquid valve is opened, said nozzle including means for retarding and breaking up the stream of material within itself before the material is discharged from the nozzle.

13. A spray gun for atomizing and spraying liquids including a body portion, a nozzle construction on the front end of said body portion for atomizing and spraying liquids by means of air pressure, said body portion being provided with a liquid passage communicating with said nozzle construction, a valve for controlling said'liquid passage, said body portion also having a liquid inlet connection communicating with said liquid passage, said body portion having an air passage leading therethrough to said nozzle construction and a valve for controlling said air passage, said air passage extending about said liquid inlet connection whereby when a pressure cup is utilized in connection with said liquid inlet connection, air may be admitted into said pressure cup from said air passage, and a pressure cup connection including a bypass arrangement affording communication between said air passage in the body portion and the pressure cup and a liquid supply tube extending into said pressure cup and secured to said liquid inlet.

14. A device of the character described, including in combination, a body member having air and liquid passages therein leading to one end-thereof, a nozzle construction on said end for atomizing the liquid by air un' der pressure, a valve for controlling the air passage, another valve for controlling the liquid passage, each valve having a horizontally arranged stem, a trigger and horizontally movable means connecting said stems, said means including a rod movable in said body, adjacent said air valve.

15. A spray gun for atomizing and spraying liquid, including a body member, a nozzle construction on the front end of said body member for atomizing and spraying liquid by means of fluid pressure, said body member being provided with a liquid passage communicating with said nozzle construction, said body member also having a liquid inlet connection communicating with said liquid passage, said body member havingvan air passage extending around said liquid inlet connection and leading to said nozzle construction, a valve for controlling said air passage, trigger means for operating said valve, and by-pass means communicating with said air passage around said liquid inlet connection, whereby when a pressure cup is utilized in connection with said liquid inlet connection, fluid may be admitted into the pressure cup through said by-pass means so that pressure may be exerted on the liquid in the pressure cup and the liquid forced through said liquid inlet connection to said nozzle construction.

16. A spray gun for atomizing and spraying liquids, including a body member, a nozzle construction on the front end of said body member, said body member being provided with a liquid passage communicating with said nozzle construction, said body member also having a liquid inlet connection communicating with said liquid passage and which projects from said body member, said body member having connected air passages leading therethrough to said nozzle construction, a valve for controlling said air passages, said passages passing around said liquid inlet connection, a by-pass pipe extending from said body member and in communication with said air passages extending around said liquid inlet connection, whereby when a pressure cup is utilized in connection with said liquid inlet connection, air may be admitted into the pressure cup through said by-pass pipe to exert pressure on the liquid in the pressure cup and force the liquid through said liquid inlet connection to said nozzle construction.

In testimony that I claim the foregoing, I have hereunto set my hand this 1st day of Feb., 1928.

AUSTIN H. DOWNS.

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