US2670239A - Dual purpose spray gun - Google Patents

Description

Feb. 23, 1954 F, D, D11-CH 2,670,239

DUAL PURPOSE SPRAY GUN Filed June 5, 1950 2 Sheets-Sheet l Feb. 23, 1954 F. D. DlTcH 2,670,239

DUAL PURPOSE SPRAY GUN Filed June 5, 1950 2 Sheets-Sheet 2 orneys Patented Feb. 23, 1954 Franklin D; Ditch,l Sheboygan;

The Electric; Sprayit Company, a; corporation-y of Delaware Wist, assigner to:

Sheboygan,

Thisv invention relates to dual" purposeA sprayVl particularly to spray gunsadapt`v guns and more able to usewith various types ofair supply sourcesl and with painting materials of'v widely differing viscosity.

An-objecti of this invention is to provide apaint spray" gun capable of interchangeable use with air supply means having self-'containedpressure' regulation,` where positive shut-ofi air control is preferred, as well as with pressure means lacking independent pressure regulation whereby it is desired that bleeder control be present in the gun'itself toprevent excessive pressure build-up.

Another object of 'the invention is tov provide a.A spray-'gun having an interchangeable positive shutoffand bleedei" type air control whereby the conversion between the control. methods can bereadily made by simple adjustment of a single valve .assembly and without' employing additional attachment elements.

A further object' is to provide in a spray gun alternative siphon and pressure paint feeding meansf,.whereby'painting materials of widely differing viscosity may be readily used in the same gun.

These and other objects and. advantages will he: more fully set forth in the following descriptionof av preferred embodiment of the invention asgillustratedin the accompanying drawings;

In the drawings Figure-.1. is a side elevation ofthe spray'gun:

with portions thereof broken away and sectioned.' The gun is. shown with its trigger released, and thet airsupply valve assembly mounted-tor provide-.a `llvositive'shut-off control;

Fig. 2 isV anV enlarged detail sectional view of theair supply valve assembly whenaconverted to provide-bleeder" air control;

Eig.;- 3fisvan enlarged detail sectional view of thegvalveassernbly of Fig. 2 showing the elements mounted as in Fig. l to provide positive shut-oi control; and

Fig. 4- is an enlarged detail sectional View of thel valve controlling the admission oi compressed air to the paint container taken along the line 4-4 of Fig. 1.

The wide application of paint spray guns has madeit desirable with` various types sources. having no independent pressure regulation.v

of compressed air supply idleness to prevent the building up of excessive:v

pressurewvhich wouldv overload the compressor whenfpressure build-,up exceeds that usedzbythe anni.

that they be capable of use Among these are portable compressors Such acompressor continuously forces air to the gun.

bleeder However; the-same gun may beemployedwith an air linerora compressor having an airstoragex which even-t itis desirable tov positively4 shut' oif thesupply of air when pain-t application; is interrupted'- to therebyl conserve the. sup piyof'air;

Thegun illustrated-comprises a body-| having: a^ handley grip-- 2; av painting materialv container@ audits container-cover il, and a discharge nozzle` The cover 4- is removably' secured tol botht-hefiled March l0, .1.950- No. 2,610,091 by the vention:

Asshown in Figi l, the portions'iof-gunbodyrl'" to which the cover dis secured,l comprises-esopo rable and readilyreniovable spray head. HowV ever, it may be'found advantageous-to' casti'the'fi spray-'head integral with otherportions of' body Il.

Air is supplied to the gun from-asource,v not shown, by suitable connectionwith` an airhose connection assemblyl 6i disposed inthe bottom oi handle grip 2.

The gun body l' contains a fluid needle 7 corrtrolling they passageffof painting material fromV the contaiIier-'v to nozzle 5,( and an air supply valve 3A regulating the new oi compressed airfrom air hose connections-assembly 6to-- nozzle 53.-

Needle 'l andvalve il normally areboth aetuated fby a triggers pivoted to gunfbody' I abouty azscrewr Ill-and depending tobetweenv handlegrip 2J andi paint container 31 Paint'v is ydrawn-immo container througlr a dipA tube li extendingupwardly through the neck offl container cover lll and' communicating with a vertical" passageway l2.y provided in gun; body l.' Verticalv passagewayl l2 connects with paint valve chamber i3. Chamber I34 extends for wardly-toa-pa'intf orice'F ld; formed at thefron'o of nozzle 5.

The forwardend of chamber r3" is frusto-conical in'shapetoseat the tip ci iluid needle 1.-

Fluid` needle lL isv reciprocably mounted in body l and extends rearwardly of paint chamber i3 to without gun body I. The rearniost portion of needle'l"I is threaded toreoeivea' ree tainingcap l5 and a needle adjustingscrew I6'. The trigger 9 isaperturedA to receive the? needle i orwardlyof' the screw- I. Screw l'G-'l may be adjusted to determine the amount oflo'st-f motion the trigger @will mairel before it'enga-ges screw i6 tovunseat needle lI thereby admittingv and dischargingpaint through' dip tube Ii, pas sage i2, chamber i3 and orificey lli.

Needle 'l isnormally biased forwardly by a` spring-pressed paint volume control assembly'y il# disposed within body' l above handlegrip 2. Biasing pressure may-be varied bythe position ing of an adjustmentscrew llthreadedtowith-r v 3 in assembly and extending to the rear of the gun.

Compressed air entering air hose assembly 6 at the bottom of handle grip 2 travels upwardly through an air tube I9 threaded within the grip to a chamber 20 provided behind air supply valve 8.

Valve 8 is disposed within a sleeve 2| carried by the gun body I. Sleeve 2| is formed with an annular shoulder 22 to seat the valve 8. A sealing cap 23 is threaded within the rear of sleeve 2| against which a needle spring 24 acts to normally bias the valve 8 to a closed position against shoulder 22. Cap 23 is sealed against sleeve 2| by ring 25.

The forward end of sleeve 2I is threaded to receive a bushing 26 which is apertured to carry needle stem 21 in coaxial alignment with valve 8.

Needle stem 2'1 has an enlarged end 28 Which, when disposed as shown in Figs. 1 and 3, abuts against trigger 9. When trigger 3 is pulled toward the handle, stem 2'.' unseats valve 8 to permit the ow of air past the valve to within a chamber 26 disposed forwardly thereof. The enlarged end 28 also acts to limit the rearward movement of stem 21 in that it is formed with a greater diameter than would permit its passage through the apertures of bushing 26 and its associated elements.

Air admitted to chamber 23 is free to pass through an annular port 33 around paint volume control assembly Il to within a longitudtnally extending air passage within the barrel portion of the gun. A passageway 3| extends forwardly from the barrel passage to communicate with discharge nozzle 5.

The flow of air through passageway 3| is further controlled by a pattern-control needle valve 32 disposed to seat against a conical orifice 33 formed at the rear end of passageway 3|. The rear end of valve 32 is received within a pattern adjusting screw 34. Screw 34 is adjustable within a threaded support to position valve 32 with respect to its orifice 33.

During operation of the gun needle valve 32 normally is maintained in an opened position and air admitted by supply valve 8 is discharged through a plurality of air passages 35 and 36 surrounding oriiice I4 in nozzle 5 while the trigger 9 is in a squeezed position.

Passages 36 by-pass pattern control valve 32 and admit air to nozzle through passageway 3| and passages 35 be closed off by valve 32 to vary the spray pattern when an external mixtype nozzle, such as nozzle 5, is employed with the gun.

With the arrangement of needle stem 2, shown in Figs. l and 3, release of trigger 3 would result in positive shut-od of air fiow due to the biasing action of spring 24 against valve 3.

To adapt the gun to use with portable compressors and other air supply means having no independent pressure control, stem 2 may be reversed, as shown in Fig. 2, whereby the enlarged end 28 of the stem 2, unable to pass through the apertured neck of bushing 26, retains the valve 8 in its open position regardless of the release of trigger 9. The gun is thus given bleeder characteristics by adapting but a single valve assembly and without the necessary addition or elimination of any members thereof.

Bushing 26 which receives the needle stem 2`| is made airtight by packing ring 31 held against the outer end of the bushing by a packing nut -inner end of bushing 4 38 externally threaded to bushing 26. A second ring 39 seals the joint between sleeve 2| and bushing 26.

To reverse stem 21 it is only necessary to unthread the bushing 26 (while still joined to the cap 38) from the sleeve 2| and reverse the tip therein, and then rethread the bushing into sleeve 2|, as shown in Fig. 2.

When the trigger 9 is in a squeezed position thereby unseating paint needle l, the flow of compressed air through discharge nozzle creates a suction at orifice I4 adjacent the mouth of the nozzle which aids in the withdrawal of paint. However, it is normally necessary to admit either atmospheric or compressed air to the container 3 to effect either a siphon or pressure feed of the paint.

It is further desirable that the valves regulating the admission of atmospheric or compressed air to the paint container be capable of rapid and exact adjustment so that the feed of paint can be promptly regulated without the necessity of shutting down the gun.

As shown in Fig. l, the cover 4 of paint container 3 is provided with a screw valve 46. Valve i6 is threaded to the cover 4 and seats upon a sealing ring 4I. When valve 46 is unseated, air is admitted from the atmosphere to container 3 through a vertical port 42 formed to one side of the valve. A valve stem 43 depending from screw valve 4e to within container 3 carries a cotter pin is which abuts against the underside of cover i to prevent the valve 40 from being completely withdrawn from the cover whereby it might be misplaced or damaged.

When highly viscous material is present in container 3 it is desirable that compressed air replace atmospheric air in forcing the material upwardly through dip tube I|. For this purpose there is provided a passage 45 which communicates with the main supply of compressed air and extends rearwardly as an extension of one of the outlet passages 36. Passage 45 turns downwardly extending through the depending portion of body I which receives container cover 4 and opens into the neck of cover 4 adjacent the dip tube The flow of air through passage 45 is controlled by a valve screw 46 which extends laterally to within gun body and is adjustably mounted to obstruct or open passage 45.

Referring to Fig. 4, valve 46 is threaded within a bushing 4l which is in turn secured to gun body i. A sealing ring 48 disposed between the 4'! and the body I encircles the valve to prevent the escape of compressed air to the atmosphere. A snap ring 49 is mounted within a groove in the stem of valve 43 to engage a counter-bore in bushing 4l and prevent valve 46 from being completely withdrawn from the bushing.

When a pressure paint feed is desired, the valve 48 in container cover 4 is closed, rendering the container airtight, and the valve 46 is backed out as far as possible to admit compressed air through passage 45 to container 3. When only a siphon feed is desired, the valve 46 is closed and valve 46 is opened to admit atmospheric air to the container.

Various embodiments of the invention may be employed within the scope of the following claims. I claim:

l. A dual purpose spray gun comprising a paint supply valve, an air supply valve, an actuating means to operate said paint valve, and aplunger-like member reversibly mounted between said air valve and actuating means to selectively control the air valve to either positively operate the same by reciprocal movement in response to said actuating means or upon reversal to retain it in open position regardless of the closure of the paint valve by the actuating means, thereby providing either positive shut-off or bleeder type air control.

2. A dual purpose spray gun comprising a paint supply valve, an air supply valve, an actuating means to operate said paint valve, a bushing disposed between said air valve and actuating means, and a plunger-like member having an enlarged end of a thickness greater than that of the bushing bore and reversibly mounted within said bushing to interchangeably control the air valve whereby the enlarged end is disposed either between said bushing and actuating means to permit reciprocal movement of the plunger to positively operate the air valve in response to said actuating means or is disposed between said bushing and air valve to space the latter in open position regardless of the closure of the paint valve by the actuating means.

3. A dual purpose spray gun comprising a gun body, a nozzle carried by said gun body, means for introducing compressed air to within said gun body, passages within the gun body to receive compressed air and direct it to said nozzle for discharge therefrom, a paint container communicating with said nozzle for the discharge of paint therefrom, a passage connecting said paint container with one of the first mentioned passages to divert compressed air to said paint container, a valve opening within said paint container to admit atmospheric air thereto and having control means operable independently of the introduction of compressed air into said gun body, and a second valve disposed within said last mentioned passage to control admission of compressed air to said container, said valves being adapted to be alternately opened to effect either Siphon or pressure feed of the contents of said container.

4. A dual purpose spray gun comprising a paint supply container, a paint supply valve controlling the withdrawal of paint from said container, an air supply valve, an actuating means to operate said paint valve, means interposed between said air valve and actuating means to interchangeably control the air valve to either positively operate the same in response to said actuating means or retain it in open position regardless of the closure of the paint valve by the actuating means, and means associated with said paint container to optionally eiect feed of its contents through the gun when said paint and air supply valves are open by utilizing pressure provided either by the atmosphere or by compressed air diverted to within the said container.

5. A dual purpose spray gun comprising a paint supply container, a paint supply valve controlling the withdrawal of paint from said container, an air supply valve, an actuating means to operate said paint valve, a bushing disposed between said air valve and actuating means, a plungerlike member having an enlarged end of a thickness greater than that of the bushing bore and reversiblyvmounted within said bushing to interchangeably control the air valve whereby the enlarged end is disposed either between said bushing and actuating means to permit reciprocal movement of the plunger to positively operate the air valve in response to said actuating means or is disposed between said bushing and air valve to space the latter in open position regardless of the closure of the paint valve by the actuating means, and means associated with said paint container to optionally effect feed of its contents through the gun when said paint and air supply valves are open by utilizing pressure provided either by the atmosphere or by compressed air diverted to within the said container from said air supply valve.

6. A dual purpose spray gun comprising a gun body, a nozzle associated with said gun body, a paint container communicating with said nozzle for discharge of paint therefrom, a paint supply valve controlling withdrawal of paint from said container, means for introducing compressed air to within said gun body adapted to optionally positively shut oi or continuously admit compressed air when said paint supply valve is closed, passages within the gun body to receive compressed air and direct it to said nozzle for discharge therefrom, a passage connecting said paint container with one of the rst mentioned passages to divert compressed air to said paint container, a valve opening within said paint container to admit atmospheric air thereto, and a second valve disposed within said last mentioned passage to control admission of compressed air to said container, said valves being adapted to be alternately opened to eiTect either siphon or pressure feed of the contents of said container.

7. A dual purpose spray gun comprising a gun body, a nozzle associated with said gun body, a paint container communicating with said nozzle for discharge of paint therefrom, a paint supply valve controlling withdrawal of paint from said container, an air supply valve, an actuating means to operate said paint valve, a bushing disposed between said air valve and actuating means, a plunger-like member having an enlarged end of a thickness greater than that of the bushing bore and reversibly mounted within said bushing to interchangeably control the air valve whereby the enlarged end is disposed either between said bushing and actuating means to permit reciprocal movement of the plunger to positively operate the air valve in response to said actuating means or is disposed between said bushing and air valve to space the latter in open position regardless of the closure of the paint valve by the actuating means, passages within the gun body to receive compressed air and direct it to said nozzle for discharge therefrom, a passage connecting said paint container with one of the first mentioned passages to divert compressed air to said paint container, a valve opening within said paint container to admit atmospheric air thereto, and a second valve disposed within said last mentioned passage to control admission of compressed air to said container, said valves being adapted to be alternately opened to eiTect either siphon or pressure feed of the contents of said container.

FRANKLIN D. DITCH.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,919,153 Andrews July 18, 1933 2,027,103 Johnson et al. Jan. '7, 1936 2,208,464 Logette et al. July 16, 1940 FOREIGN PATENTS Number Country Date 413,213 France May 20, 1910

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