US1992426A - Spray gun - Google Patents

Description

Feb. 26, 1935. A. M. HERBSMAN x-:T AL

SPRAY GUN Filed Jan. 25, 1933 2 SheetsSheet l Feb- 26, 193s. A. M, HERBSMAN Er AL 1,992,426

SPRAY GUN Filed Jan. 25. 1955 2 Sheets-Sheet 2 Patented Feb. 26, 1935 PATENT OFFICE SPRAY GUN Abraham M. Herbsman, Huntington Park, and Rodney B. Campbell, Walnut Park, Calif.; said Campbell assignor to said I-Ierbsman Application January 25, 1933, Serial No. 653,386

Claims.

Our invention relates to spray guns and has for its general object the provision of a spray gun which is readily adapted to selectively throw Aa stream of air, a stream of liquid, or an atomized 5 spray; to provide a spray gun which is relatively safe from excessive line pressure; to provide a, spray gun which is simple and relatively light in construction; to provide in a spray gun a novel, inexpensive, and readily demountable valve structure having a replaceable valve seat; and to provide in a spray gun a novel, inexpensive, and readily demountable nozzle construction which will facilitate the ready cleaning of this element of the gun.

Further objects and advantages will be made manifest in the following description taken in connection with the accompanying drawings, in which:

Fig. 1 is a side elevationalview of the preferred embodiment of our invention.

Fig. 2 is an enlarged vertical sectional view of a portion of the device shown in Fig. 1.

Fig. 3 is a fragmentary enlarged vertical sectional view taken on the line 3--3 of Fig. 1.

Fig. 4 is a plan view of the nozzle means of our invention partly broken away to illustrate the construction thereof.

Fig. 5 is an enlarged horizontal sectional view taken on the line 5-5 of Fig. 2.

Fig. 6 is an enlarged sectional view taken on the line 6--6 of Fig. 2.

Fig. 7 is a fragmentary plan view taken in the direction of the arrow 7 in Fig. 2.

Referring specifically to the drawings, a preferred embodiment of our invention is shown in Fig. 1 and indicated generally by the numeral 10. The spray gun 10 includes a tank and control section 11 and a nozzle section 12. The tank and control section l1 has a body 14 which provides a base for the formation of a tank 15, a handle 16, a pressure regulator 17, and a valve mechanism 18.

The tank 15, as shown in Figs. 1 and 2, has a lower rim 22 formed to receive a packing ring 23. The bottom of the tank l5 is open and is adapted to be closed by a cover 24 which is forced upwardly against the packing 23 by a nut 25 screwed on the lower end of a pipe 26 which passes downwardly through an aperture 27 formed centrally in the cover 24. The pipe 26 extends upwardly through the hollow handle 16 and is threadedly received in an aperture 30 provided in the body 14 at the' upper end of the handle 16. Disposed between the nut 25 and the cover 24 is suitable packing 31 which prevents any leakage of liquid from the tank l5 around this nut. The lower end of the pipe 26 is provided with suitable holes 33, and these holes are surrounded by a screen 34 to prevent solid particles from entering the pipe 26 from the tank 15. 'I'he upper portion ofthe handle 14 is formed to provide front and rear projections 35 and 36 respectively as shown in Figs. 1 and 2.

The body 14 is provided with a ring 38 at the upper end of the handle 16, this ring forming a 16 base for the regulator 17 and enclosing a chamber 39, one end of which is closed by a wall having a threaded neck 41. The neck 41 has a passage 42 and suitable valve seat means 43 removably held in place at the outer end of this passage by 16 a bonnet 45.

Secured against opposite faces of the ring 38 are regulator housings 47 and 48. The housing 47 tightly clamps a diaphragm 49 over the open end of the chamber 39, this diaphragm having a 20 central opening 50. Provided axially in the housing 47 is a pressure regulating screw 52 having a lock nut 53 provided thereon. Extending through the opening in the diaphragm 49 and rigidly secured thereon, as shown in Fig. 5, is a valve 25 mounting 55, this mountingsupporting a valve 56 having a stem 57. Coiled about the stem 57 between the housing 48 and the valve 56 is a spring 60 which tends to force the valve 56 against the seat 43. Interposed between the regulator valve 30 i mounting and a cap 62 supported on the screw 52 is a pressure regulating spring 63 which tends to overcome the pressure of the spring and open the valve 56 when less than a predetermined maximum pressure prevails in the chamber 39. 35 The housing 48 forms a pressure chamber 68 with which the upper end of a tube 69 connects, this tube being preferably cast into the body 14 when this is formed so that the lower end of the tube connects with an air pressure hose receptacle 70 40 provided in the body 14. Connecting the chamber 39 with the hollow interior of the handle 16 and the tank 15 is a duct 72, as shown in Figs.

2 and 5.

The tank 15 is provided with a suitable thread- 45 ed filling aperture which is normally lled by a plug 76, this plug having a spring-pressed safety valve 77, the latter permitting an escape of air from the tank when the internal pressure rises above the predetermined maximum. This maxi- 50 mum is preferably under ten pounds to the square inch.

The body 14 of the tank and control section 11 extends forwardly from the ring 38 to provide a trigger neck 80, a valve base 8l, and a nozzle base 55 82. The trigger neck is divided centrally to form a well through which a trigger 86 extends, this trigger being pivotally supported upon the body 14 at the upper end of the well 85. The trigger 86 is provided at its upper end with an arm 88 upon which a valve actuating cam 89 is rotatably mounted, there being a detent 90 provided in the arm 88, as shown in Fig. 7, which engages suitable recesses in the cam 89 so as to retain this in any one of three positions, as will be explained hereinafter.

Provided on the body 14 in line with a lower portion of the trigger 86 is an adustable screw stop 92, this stop limiting therearward movement of the trigger 86 and regulating'the amount of opening in valves 106 and 106'.

As shown in Fig. 6, the valve body 81 has al pair of parallel valve assemblies 93 and 93' disposed in parallel holes 94 and 94 which extend clear through the valve base 81. The assembly 98 and hole 94 will now be described in detail, it being understood that corresponding parts of the assembly 93 and hole 94' will receive the same reference numerals with a prime added.

The hole 94 includes a push pin guideway 95 which is enlarged at its upper end to receive a gland 96, the latter forming a seal around a push pin 97 which is slidably received by the guideway 95. The guideway is counterbored progressively at its lower end to provide an outlet passageway 98 and a valve unit chamber 99. As the chamber 99 is larger in diameter than the passageway 98, an annular shoulder 100 is provided at the juncture of these counterbores. The lower end of the chamber 99 is internally threaded.

The valve assembly 93 lies in the chamber 99 and includes a valve seat 101 which is pushed against the shoulder 100 by a valve shell 102, the latter being screwed into the lower end of the chamber 99. External threads for this purpose on the shell 102 extend downwardly below the lower end of the chamber 99 so as to threadedly receive a cap 103 for sealing the lower end of the chamber 99 from the atmosphere. The valve shell 102 has a bore 105 which is only slightly larger than a valve 106, this valve having a stem 107 which is slidable in a suitable guideway 108 provided in the lower end of the shell 102. Wound about the stem 107 and urging the valve 106 into seating relation with the seat 101 is an expansive coil spring 110. Formed in the outer surface of the shell 102 is an annular fluid inlet' passage 112 which communicates by suitable holes with the bore in the shell 102.

The nozzle base 82 extends substantially horizontally from the valve base 81 and is provided with threads 120, the end face of the base having a pair of annular ridges 121 and 122. Connecting the space inside the ridge 121 with the uid outlet passageway 98', as shown in Fig. 5, is a liquid duct 123. Connecting the space between the ridges 121 and 122 with the fluid outlet passageway 98 is an air duct 124. Connecting the recess 30, shown in Fig. 2, with the chamber 99' opposite the inlet passage 112' is a liquid. duct 125.V Connecting the air chamber 39, as shown in Fig. 5, with the chamber 99 opposite the inlet recess 112 is an air duct 126.

The nozzle assembly 12 includes a tubular outer shell which is closed at its inner end by a plug 1'31 and at its outer end by a plug 132. Threadedly received in the plug 131 and extending through a hole 133 in the plug 132 is an inner tube 134. 'Ihe plug 131 has a hole 135 communieating with the inside of the inner tube 13 4 and holes 136 communicating with the space between the inner and outer tubes. 'I'he hole 133 of the plug 132 has a counterbore 137 into which a nozzle 138 is extended and rotated so as to be threadedly screwed onto an adjacent threaded end of the inner tube 134, as sh'own in Fig. 4. Thus, the plugs 131 and 132 are pressed together against opposite ends of the outer shell 130, thus rigidly assembling the outer shell and the inner tube 134. The plug 132 has holes 140 which communicates between the space inside the shell 130 and the counterbore 137. The plug 132 has external threads which are adapted to receive a lock nut 141 and an external nozzle shell 142. The lock nut 141 is adapted to lock the shell 142 on the plug 132 in various longitudinal positions relative to the nozzle 138.

The plug 131 has an annular ange 144 which retains a union bonnet 145 in place on the nozzle assembly 12. This bonnet is adapted to screw onto the threads 120 on the nozzle base 82 so as to connect the hole in the plug 131 with the liquid duct 123 of the base 82 and connect the air openings 136 in the plug 131 with the air duct 124 in the base 82. Fig. l shows the entire device assembled ready for operation, this being effected in the following manner:

Operation The spray gun 10 is adapted to be used in applying liquids in a solid stream or spray, such as the applying of oil to machinery for lubricating the same, or for applying germicides to plants or the applying of paints and lacquers to surfaces to be coated therewith. To begin the operation, a quantity of liquid to be applied is placed in the tank 15 through the opening 75 and the plug 76 then replaced in this opening. A suitable pressure hose is connected with the receptacle 70 so that a line pressure preferably in excess of ten pounds to the square inch is supplied to the device. 'Ihe air from this hose passes up the pipe 69 into the chamber 68 and, entering the chamber 69 through the valve passage 42, builds up the pressure therein so as to expand the diaphragm 49 against the pressure of the spring 63, thereby closing the valve 56. The screw 52 is preferably adjusted so that a pressure of seven pounds to the square inch in the chamber 39 effects the closing of the valve 56. An air pressure of approximately seven pounds per square inch above atmospheric is thus maintained in the chamber 39 and in the tank 15 with which this chamber is freely connected by duct 72.

Owing to the pressure of the springs 110 and 110 the valves 106 and 106' are normally held closed as shown in Fig. 6. In Fig. 7, the cam 89 is shown as held crosswise by the detent 90. If the trigger 86 is now pulled by a linger of the hand grasping the handle 16, both of the valve push pins 97 and 97 are simultaneously pushed down, thus opening both of the valves 106 and 106'. This results in a stream of liquid owing up the pipe 26 through the duct 125, past the valve 106', and through the duct 123 into the inner nozzle tube 134 from which it is ejected through the nozzle 138. Also a stream of air is at the same time released from the chamber 39 through the passage 126, past the valve 106, and through the duct 124 into the space between the outer shell 130 and inner tube 134 of the nozzle assembly 12, this air passing through the holes in the plug 132 'so as to be expelled eventually from the outer nozzle 142, thus breaking up the liquid coming from the inner nozzle 138 and forming it into a spray. It is of course understood that the adjustment of the outer nozzle shell 142 on the plug 132 is for the purpose of forming a satisfactory spray with liquids of different degrees of viscosity and density.

Under some circumstances, a solid stream of liquid is needed, in which case it is desirable to open the valve 97' alone when the trigger 86 is pulled. This is accomplished by manually swinging the cam 89, as shown in Fig. 7, in a clockwise direction so that this cam is disposed away from over the valve push pin 97. Thus, when the trigger is pulled the push pin 97 only is depressed so as to open the valve 106' and this results in a solid stream of liquid being emitted from the nozzle 138.

On the other hand, it is sometimes desired to use the spray gun 10 to emit a stream of air alone as where it is necessary to blow dust from the object to which the liquid is to be applied. To accomplish this the cam 89 is swung about its pivotal mounting in an anti-clockwise direction so that the cam is disposed away from over the valve push pin 97'. Thus when the trigger 86 is pulled, the pin 97 only is depressed, thus opening the valve 106 while the valve 106 remains closed. This results, of course, in a stream of air only being emitted from the outer nozzle shell 142.

When the gun 10 is being used, the operators hand grips the handle 14 as shown by the dotted lines of Fig. 2, it being noted that the projections 35 and 36 rest on the third finger and crotch of the thumb respectively, thus providing means for supporting the weight of the gun without the necessity of the operator having to grip the handle tightly.

From the foregoing description it is seen that we have produced a novel spray gun having a number of features constituting improvements over the prior art. The bottom cover 24 of the tank 16 is not only held in place by the standpipe 26, but the point at which liquid is taken into the standpipe from the tank leaves an annular sump adjacent the outer portions of the cover 24 in which sediment may collect. thereby preventing this sediment having ready access to the screen 34 and preventing this screen from being clogged.

While we have shown a single preferred embodiment oi' our invention, it is to be understood that various modifications might be made in this without departing from the spirit of the invention or scope oi' the appended claims. i

What we claim is:

1. In a spray gun, the combination of: a body providing a liquid tank; a handle extending upward from said tank; an automatic air pressure reducing valve on said handle; manually controlled separate air and liquid valve means on said handle; a spray -nozzle on said handle; means connecting said reducing valve to said tank and said valve means to supply air at av predetermined relatively low pressure to said tank and to said air valve means; means for conducting liquid trom said tank to said liquid valve means; and means for separately conducting air and liquid from said valve means to said spray nozzle, said valve means separately regulating the now of said air and said liquid.

2. In 'a spray gun, the combination oi': a body providing a liquid tank; a handle extending upward 'from said tank; an automatic air pressure reducing valve on said handle; manually controlled separate air and liquid valve means on said handle; a spray nozzle on said handle; means connecting said reducing valve to said tank and said valve means to supply air at a predetermined relatively low pressure to said tank and to said air valve means; means for conducting liquid from said tank to said valve means; means for separately conducting air and liquid from said valve means to said spray nozzle; a trigger pivotally mounted on said handle between said pressure reducing valve and said valve means and adapted to be pulled by a iinger of a hand gripping said handle; a valve actuator shiftably mounted on said trigger, and disposed to engage and actuate said valve means, said actuator having liquid iiow, air flow, and spray iiow positions on said trigger; and a detent for yieldably holding said actuator in any one of said positions.

3. In a spray gun, the combination of a body providing a liquid tank; a handle extending upward from said tank; an air pressure reducing valve provided on the upper end of said handle; separate air and liquid valve means; means for supplying air under pressure; conduit means connecting said air supply to said reducing valve; air conduit means leading from said reducing valve to said tank and to said air valve means; a liquid conduit leading from said tank to said liquid valve means; a neck joining said regulator to said valve means, said neck having a vertical well therein; a trigger extending vertically through said well and pivotally mounted on said neck; a valve actuator mounted on said trigger at the upper end of said wellnin position to actuate said valve means, said actuator being shiit able on said trigger to operate said valve means to release different proportions of air and liquid when said trigger is pulled; and a spray nozzle through which air and liquid from said valve means are discharged.

4. In a spray gun, the combination of: a tubular outer nozzle shell; heads for closing opposite ends of said shell, said heads having central coaxial apertures; an inner tube extending through said shell and into said apertures; means engaging with ends of said inner tube and said heads to compress said heads against ends oi said outer shell, said last mentioned means including a nozzle at one end of said inner tube; and secondary nozzle means on the head adjacent said nozzle and surrounding the latter, there being openings provided in said heads to permit free passage of liquid through said inner tube to said nozzle and of air through the space between said inner tube and said shell to said secondary nozzle means.

5. In a spray gun, the combination of: a body providing a liquid tank, a handle and a head having separate air and liquid valve means, and means for connecting a spray nozzle to said valve means so that air and liquid are discharged from said valve means through said spray nozzle, the bottom of said tank being-open; a cover for said tank bottom; a pipe for conducting' liquid from the bottom of said tank to said liquid valve means, said pipe being connected to said head; 4

and means on the lower end of said pipe and operable from beneath said tank to press said bottom cover into place over the open bottom of said tank, said bottom cover sloping from the middle outwardly so as to form an annular sediment trap.v

ABRAHAM M. HERBSMAN. RODNEY B. CAMPBELL.

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