US2550888A - Spray gun - Google Patents

Description

May 1, 1951 c. w. TRAUGHBER, JR

' SPRAY GUN 2 Sheets-Sheet 1 Filed Jan. 13, 1948 FIG. I.

Pa: CHARLES 144 M40 @Wf'm A TTORNE Y May 1, 1951 c. w. TRAUGHBER, JR

SPRAY GUN 2 Sheets-Sheet 2 Filed Jan. 13, 1948 w m w Y J 4 2 7- a a a 7 1n 7 5 I 1 2 ZI .H Mm 7 3 M743 INVENTQR. CHARLES W. TRAUGHBER, JR

Arron/var Patented May 1, 1951 UNITED STATES ATENT OFFICE 4 Claims. 1

' -'I'hisinvention refers to s raying equipment and more particularly to a spray gun for use in. mixing materials with a pneumatic pressure agent, for discharging the materials under pres-' sure, against a suitable surface close'by, tocover it with a film or coating of the materials.

The'conventional type of spray gun used commercially for industrial or domestic use, uses air under pressure to carry liquid or powdered materials in the stream discharged from its nozzle. The materials are injected into the discharge stream by the suction of the pressure air stream. If the nozzle becomes choked up, the pressure from the air tends to act inside the nozzle and against the container from which the materials were intended to be sucked. If the discharge from the nozzle is impeded in any way, the suction action on the materials is decreased in proportion. This causes a less satisfactory discharge and the efiicacy of the spray gun is substantially diminished. The suction induced by the air stream affords an indirect pressure on the materials to be applied. It acts only on the surface of the top ingredients held in the container, its mixing action thereon is not as satisfactory as would be desired, unless of course the original materials are relatively light, uniformly distributed in the container and of the same specific gravity. This is seldom the case. pulled up to the nozzle in a more compact state than they would if they were blown up from behind. The pressure air stream also has to use up a great part of its energy in drawing up the materials to the nozzle before mixing them with the air, prior to the discharge through the nozzle. In order to overcome these and other objections it is the object of this invention to provide a new and improved spray gun that will avoid one o'r'more of the disadvantages and limitations of the prior art.

Another object of the provide a new and improved spray gun that will employ pneumatic pressure to directly injectappliable materials into .the gun as well as cause the mixture and discharge therefrom.

An additional object of the invention is to provide a new and improved spray gun that will have a self cleaning action and have all parts and passages subject to the spraying maneuvers of the materials and air pressure, continuously swept by the air currents employed while in use. A further object of this invention'is to provide a new and improved spray gun having a balanced pressure of air and materials to be atomized during the spraying operation; to have Besides the ingredients are present invention is to 2 q adequate adjustment for control of the air pressure and materials, and a variable arrangement for controlling the type of spray, as well asuse its air pressure more eifectively.

It is an additional object of this invention to provide a swirling motion ofair and materials. in

the mixing chamber nozzle to break up any small. lumps of material collected therein.

A further object of the invention is to provide a new and improved spray gun having its nozzle cushioned on the inside by the air spray to reduce \the wear of the abrasive "passing therethrough.

Other objects will become apparent as the in'! vention is more fully set forth.

For a better understanding ofthe invention, and the objects thereof, reference is made to the accompanying drawings, and the following de-' scription. These together, describe a particular form of the invention by way of example, while the claims indicate the scope'thereof.

In the drawings:

Figure 1 is a plan view of a spray gun embodying this invention;

Figure 2 is a side elevation of Figure 1, with parts broken away to show its construction, and with a diagrammatic view of the feeding mechanism; r

Figure 3 is a rear end view of Figure 1;

Figure 4 is a sectional view taken along lines 4-4 of Figure 2';

Figure 5 is a sectional view taken along lines 5-5 of Figure 2;

Figure 6 is a sectional view taken along lines 6--6 ofFigure 2;

Figure 7 is an exploded view of the spray end of Figure 2;

,Figure 8 is a front, elevation of the disc, and

Figure 9 is an end view 'of the disc looking in the .direction of arrows 9-9 of Figure 8. f Similar reference 'characters'refer to the-same parts throughout the drawings. In the particular form of the invention shown, a'spray' gun consists'of a hollow handle It, including a passage H longitudinally disposed therein and connecting at its upper end with a passage 9. A fitting I2 is provided at the butt of the handle for attaching a pneumatic hose thereto. The projections I3 and M on the front and back of the handle are termed grips to permit the handle to be conveniently handled. A boss I 5 threaded interiorly for an adjusting screw 16 controls the travel of a trigger I 'I pending from the portion I 8 of the barrel 22"attached to the handle {'ID at approximately right angles thereto.

A plug 59 closes up the passages 9 and H and serves as a cap. This plug l9 allows access to the interior of the passage 25 that runs through the barrel 22 at the top of the passage 9, which it is connected to at right angles. The rear end of the barrel 22 is provided with an adjusting screw ill for regulating the amount of air passing through the spray. Usually the line 5! can be left open and the amount of material sprayed from the gun is controlled by the adjusting screw 51. The screw can be used to close off the air supply. Packing nut 95 supports the adjusting screw 9|, and packing 92 prevents leakage from the passage 25. The front chamber portion 2| of the barrel 22 is extended downwardly from the barrel 22 at right angles and has its passage 23 depending downwardly at right angles to'the end of the passage 29 and is of the same general size. All these passages are preferably circular in cross-section. An outlet 24 extends transversely through the wall of the chamber portion 2i into the trough 25 provided in thread-portion 55. A retaining nut 26 screws on to the exteriorly screw threaded periphery of the portion 55 and holds a tapered mixing outer nozzle 2'! thereto by its flange 28 and against the disc 29 set in the union recess 35. The outer nozzle nose 5! has an axial threaded orifice 82, which is adjustably and interchangeably screw threaded therein. An inner nozzle 34 extends into the mixing chamber 35, in

the outer nozzle 21, from the front wall 36 of the chamber portion 2|.

This inner nozzle 34 has a tapered exterior surface 31 having-holes 38 drilled therethrough at an angle of about 45. gular sprays of material into chamber from the axial passage 35 in the spout 34. The interiorly screw threaded head 46 on the sleeve serves as a spacer and clamps the disc 29 to the inner nozzle 34 whichis arranged. radially in the groove 4| inits periphery. The sleeve ill passes transversely through the Walls of the portion 2! and is clamped thereto by the head 44 and the stuffing box cap 42. The interior 15 of the sleeve 40 is of larger diameter than the passage 39 and has a piston is travelling in itto close or open the inlet port 55 in the wall of the sleeve. The

inlet port 55 is preferably of rectangular form with its longest portion running longitudinally with passage 75. The piston rod 55 reoiprocates the piston 53, and projects through a slot Tl, in the trigger H, and is adjustably positioned in a collar or adjuster #8. A piston rod 79 is connected to the other end of the adjuster l8 and operates another piston 55 in a cylinder i! installed transversely in the handle [0 and held therein by the head 48 and stufiing box cap 49. The coil spring 50 keeps the pistons under tension through the aid of cap 8'5 and tending to close the ports 55, and 95, which respectively allow the materials and air pressure streams to pass into the mixing chamber of the nozzle through the passages 38 and 25. The ports 55, and 9-5 are preferably of rectangular form like port 45 to give better support to the pistons 53 and 56. A stop 8'! is positioned on rod i9 to limit its travel. The materials are introduced through the passage 85 by a hose 59 attached to the fitting 52- which is screwed to the chamber portion 2! and then through the port 35, interior l5, passage 39 through holes 38 into chamber 35. The air enters through the passage-ii and passes through theports 55 and 95 into passages Sand 25- 50 23 then through slots 5'! into chamber 35. The pis ton rods 45 and Fe-are operated by the trigger This is to provide anl1 acting on the adjustable nut 18 as the trigger i1 is pulled by the hand of the user. The trigger is preferably of the channel construction shown in the drawings. The disc 29 has slots 57 set out radially therein and bevelled oppositel to cause a diversion of the air pressure stream coming therethrough into an angular plane.

The operation of the device is as follows. It is assumed that a hose 54 is attached to the fitting l2 and provides air at 60 p. s. i. from an air feed line 82. A second air line 83 is connected to the air feed line 82 at one end and the other end is connected to a material tank 85 to maintain the same air pressure in the tank as is placed on the spray gun and to stir the tank materials. A hose 5! is attached from the upper end of the material tank tothe inner nozzle 35 at 50 p. s. i. A valve 85 controls the air supply to the bottom of tank 85. An air bleeder 93 is attached to the tank 84 and through its valve 55 controls the escape of air from the tank. The amount of escaping air is approximately 1 to 2 cubic. feet per minute during the time the materials are mixing. Water mixed material. are supplied to the tank 54 through the hole covered by cap 60.

The operator holding the handle 15 pulls the trigger l1 backwards so the piston 55 will open the ports 55 and 95 in the handle and upper passage 9 so the air pressure stream will start passing through slots 5'! in disc 28 into the mixing chamber 35. An instant later the port 45 opens and allows the materials to be forced through the inner nozzle 34 into the mixing chamber-35i 'As' the trigger I1 is pulled over more and moves the pistons 43 and 56 to open the ports more, it unthrottles the streams of air and materials. The full pressures of each cause the air passing at an angle through the slots 51 in the disc 29 to mix with the materials ejected under pressure into the chamber 35 at an angle with each turbulently and/or cyclonically combining therein, before passing through the interchangeable orifice 32 on its way to be used on the surface to be sprayed. When the trigger I! is released, its pistons 53 and 55 pass over the ports 45, 55 and 95 and close them. The air pressure stream asses through the slots 51 in a turbulent and/or cyclonic manner which prevents the material from sticking on the walls of chamber 35. The stream continues through the chamber 35 as it bounces from the wall towards the axis of the chamber and combines at the end of the inner nozzle 34 with the angular squirting of materials through the holes 38, under pressure. This mixture is further concentrated in the converging poriion. of the chamber 35 and flows through the orifices in the screw orifice 32 at high speed and thoroughly mixed. The purpose of the initial opening of the ports 55 and 95 by the piston 56 before that of the port 55 by the piston 43 is to anticipate the lag .due to the great distance through the passages ll, 5, 20 and 23,

in the handle and barrel that the compressed air from the passage H has to pass through before reaching the mixing chamber 35. Thus the main air stream from the hose 54 is flowing into the chamber 35 at approximately the same time as the materials with its air stream carrying the particles arrive in the chamber 35. Both main air stream and materials mix in a cyclonic manner under their respective pressuresand coordi hate-with each other without any loss of energy. The particles are thrown with considerable kinetic energ into the chamber 35 which is boostedby the air stream from the hose 5% connected to the passage H. i The mixture is enhanced by the angular spread out streams of air through the slots 51 in the disc 29 as they bounce against the chamber walls and the surfaces of the inner nozzle 34. As the streams pass through the holes 38 with their air and particles of materials rushing through with considerable violence, the turbulent and/or cyclonic air streams coming through slots 57 are intermixed and break up the particles of the materials so they are evenly spread throughout the streams and rush out of the orifice 32 fully mixed and at high pressure.

The thorough mixture of the materials within the balanced pressurized streams prevents any tendency to create open spots or areas during distribution of the spraying materials against the surface being treated. The spraying becomes clear cut and the application of the material can be controlled from a fine film to a heavy coating. The various adjustments enable the gun to be accurately arranged for any work within the scope of its duties, and the arrangement of the passages and parts permit facile inspection, cleaning and replacement, of parts.

While but one general form of the invention is shown in the drawings and described in the specifications, it is not desired to limit this application for patent to this particular form, as it is appreciated that other forms of construction could be made that would use the same principles and come within the scope of the appended claims.

Having thus described the invention, What is claimed is:

1. A sprayer including a main body having a pair of spaced-apart and co-axial chambers thereon, passage means for admitting compressed 'fluid to one of said chambers through a port opening therein, passage means for admitting spray liquid to the other of said chambers through a port opening therein, a piston in each of said chambers controlling each of said port openings, a pair of aligned piston rods connected to'said pistons, means for adjustably connecting said piston rods together, a trigger pivoted on said main body, said trigger having an opening to allow passage therethrough of the adjustable means for said piston rods.

2. A sprayer as set forth in claim 1, wherein the piston controlling the port opening for the admission of compressed fluid, opens the said port opening prior to the opening by the other of said pistons of the port controlling the spray liquid.

3. A sprayer as set forth in claim 1 in combination with means for adjusting the normal position of the trigger and maintaining it in such adjusted position.

4. A sprayer as set forth in claim 1, said sprayer having a handle grip and said trigger having means for adjusting its normal position, said means comprising an element secured to said grip and a screw threaded in said handle grip.

CHARLES W. TRAUGHBER, JR.

REFERENCES CITED The following references are of record in the file of this patent:

' UNITED STATES PATENTS

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