US2864649A

US2864649A - Spray gun

Info

Publication number: US2864649A
Application number: US624418A
Authority: US
Inventors: John R Adams
Original assignee: Cline Electric Manufacturing Co
Current assignee: Cline Electric Manufacturing Co
Priority date: 1956-11-26
Filing date: 1956-11-26
Publication date: 1958-12-16
Anticipated expiration: 1975-12-16

Description

J. R. ADAMS Dec. 16, 1958 SPRAY GUN Filed Nov. 26, 1956 INVENloR. M @darmi United. States SPRAY GUN .lohn R. Adams, Chicago, ill., assigner to Cline Electric Manufacturing Company, Chicago, ill., a corporation of illinois Appiication November 26, 1956, Serial No. 624,418

8 Ciaims. (Cl. 299-14031) shaping the spray and/ or further atomizing the sprayed material.

In presently commercially available spray guns of the general type contemplated herein, it is the Vusual practice to provide a central nozzle tip through which material to be sprayed is directed, which tip is surrounded by a central air or gas orifice which directs the central stream of air for, in most cases, drawing the material from the tip and/or atomizng the material. Additional laterally disposed orifices are arranged for directing air or gas against the central spray for forming the spray into a particular shape for engaging a workpiece in a desired manner, and, for example, the lateral air orifices may be used to form the central spray into a fan shape so as to cover a wider area of a workpiece. As will be understood, the character and shape of the spray may be adjusted by controlling the pressure of the air or gas delivered to the central air orifice and by controlling the pressure of the air or gas delivered to the lateral orifices.

An important object of the present invention is to provide a novel spray gun of the type described wherein means is provided for controlling the pressures of the air delivered to the central and lateral orifices from a common supply passageway independently of each other or, i

affecting the pressure of the air delivered to the othery orifice.

A more specific object of the present invention is to provide a novel spray gun of the above described type which includes novel and simple valve means disposable in a single bore for independently controlling the flow of air to the central orifice and to a lateral orifice whereby to facilitate easy and economical production of the spray gun and also to enable certain features of the novel spray gun to be incorporated into presently available spray guns.

Still another object of the present invention is to provide a novel spray gun of the above described type which is constructed so that manually operable elements respectively for .effecting control of the air to the central orifice and control of the air to a lateral orifice are disposed at a common location so as to facilitate proper adjustment of the spray gun.

Other objects and advantages of the present invention will become apparent from the followingdescription and the accompanying drawings, wherein:

Fig. l is a longitudinal sectional view of a spray gun incorporating the features of the present invention;

' Fig. 2 is a perspective view showing an element of the novel valve means in the spray gun of the present invention;

smooth wall section 32.

the back end of the body member 24 in communication 2,854,649 vPatented Dec. 16, 1958 Fig. 4 is an enlarged fragmentary sectional view similar to big. l but showing elements of the air or gas control valve means shifted to different positions.

Referring now more specifically to the drawings wherein like parts are designated by the same numerals throughout the various figures, an automatic spray gun incorporating the features of the present invention is shown in Fig. 1.. However, it is to be understood that 'certain features of the present invention may be equally wellap plied to a manually operated spray gun. In generaLthe spray `gun lil comprises a body member 12 having-a gas or air inlet passageway 14 and a spray material inlet passageway 16 formed therein, a nozzle assembly 1S secured to one end of the body, gas or air control valve means 20 disposed within the body, and needle valve means 22 for controlling the iiow of material to be sprayed from the nozzle.

In the embodiment illustrated, the body means 12 comprises a casting 24 havingthe air inlet passageway- 14 formed therein, which passageway has an enlarged internally threaded section 26 adapted to receive a complementary coupling member of an air line, not shown, which extends ,to a suitable source of air underpressure as will be understood. The passageway 14 communicates with a bore extending generally longitudinally of the body member 24 and including an internally threaded section 28, a smooth wall section 30 Vand a` reduced diameter A chamber 34 is provided at with the air inlet passageway 14 for housing actuating piston means of the needle valve assembly 22. k

The `spray gun body means 12 also includes` a body member or casting 36 secured to the forward end of the body member or casting 24 and having a-nipple 38 with the passageway 16 formed therethrough adapted to be connected with a conduit for spray material' to the gun. A bore 40 is formed in the body member 36 in axial alignment with the bore 32, which bore 40 is connected by a reduced diameter passageway 42 with an annular .space 44. A separatevpassageway 46 is formedin the member 36 for establishing communicaiton between an annular space 48 and a space 50 in the body member 24 which in turn communicates with a side of the bore 32.-

The nozzle assembly comprises a central tip member 52; which is threaded into an internal tubular projection 54 of the body member 36 and has a relatively large cen tral passageway 56 communicating with thel spray material inlet passageway 16. The tip member 52 is provided with a reduced diameter discharge orifice 5S and l a spacer member 70 having opening 72 therethrough is" provided between the tip member 52 and the outer tip,` ,member 62 so that air flows to the central air orifice 66 through a passageway provided by the space 50, the bore 46, the annular space 48, the opening 72, and a space 74" between the outer end of the tip member 52 and the tip member 62. v

The outer tip member 62 is'provided with forwardly projecting ears 76 and'78 having passageways 80 and 82 therein communicatnig with the annular space 44 through openings 84 provided in the adapter ring 68. Discharge orifices d6 and 88 are provided in the ears and extend :from the passageways Sli and 82 for directing streams of air against the central spray for forming or shaping the spray ina desired manner.

The valve means for independently controlling the flow of air or gas to the central orifice 66 and

thelateral orifices

86 and 88 includes a bushing 90snugly disposed in an end portion of the bore 32 and also within an enlarged section of thverbore 4,0 in the body member 36. The `bushing 90 is provided with an annular series of apertures 92 which provide a lateral opening from the bore 32 communicating with the space 50. A first valve member 94 has an annular section 96 slidably disposed in theA bore 32 and a reduced diameter section 98 slidably disposed in the bushing 90.and connected to the section 96 by

narrow arms

100 and 102. An `O-ring 104 is positioned in a-suitable annular groove. formed in the valve member section 96 for providing a seal between this valvemember section and the wall of the bore 32. A similar O-ring 106 is mounted in a groove in the valve member section 98 for preventing the passage of gas or air under pressure between the bushing 90 and the valve member sectiorl98.` The valve member 94 is welded or otherwise connected `to a tubular member 108 which extends rearwardly through the bore 32' andlhas its opposite end welded or otherwise connected to a manually operable knob member 110. The knob member has an intermediate threaded section 112 turned into the threaded'bore section 28 and an outer enlarged end portion 114 which may be easily grasped and turned by an operator. An `(J-ring 116 is mounted in a suitable groove in an inner end section 118 of the knob member for engaging the wall of the bore to prevent the escape of air or gas under pressure past the knob member. It will be appreciated that upon turning of the knob member 110, the valve member 94 will axially be adjusted relative to the lateral `valve opening 92. With the parts in the position shown in Fig. l, the valve member section 98 is disposed so that the apertures 92 are completely open. Upon turning of the knob`member`110 in the proper direction the valve member may be retracted to the position shown in Fig. 4 so that the section 98 will partially close the apertures 92 andthereby reduce the flow and pressure of the gas or air directed to the central orifice 66, andif desired, the valve member could be shifted so as to close completely the apertures 92.` The tubular member 108 is provided with one'or more apertures 120 therein pro. vidmg communication between the bore and the interior'y of the -tubular member, so that gasv or air under pressure entering from the passagewayili will pass through the passageway provided by thetaperture 120, the interior of the tube 108, and aperture 122 through the annular valve member section 96 and the space between the

valve member sections

96 and 98. From this space, a portion ofthe gas will, of course, ow through the lateral openings92. whenthese openings are uncovered or at least partially uncovered` by-thevalve member section 98.

The valve member section 98 has a central aperture 124 therein and a valve seat` 126 which define a valve opening betweenthe supply gas passageway and the passageway to the .lateral or

fan orifices

86 and 88. A second valve member 128 is provided for cooperating with the valve seat 126 and thereby controlling the flow and pressure of the `air directed to the lateral or

fan orices

86 and 88. The needle valve 128 has a long stem extending rearwardly through the tubular member 108 and connected by a pin 130 or any other suitable means to tween the knob members. With this arrangement it is to be noted that when the outer knob member 110 is turned to adjust the first valve member 94, the valve member 123 will move as a unit with the valve member 94 so that the relationship between the valve member 128 and the valve seat 126 will be unchanged. However, adjustment of the valve member 128 relative to the valve seat 126 may be easily accomplished by turning the knob 132 relative to the knob 110. Thus, it is seen that the streams of air or gas flowing through the valve openings 92 and 126 may ybe controlled independently of each other.

The needle valve assembly for controlling flow of material to be sprayed comprises an elongated needle valve 144 which is cooperable with the valve seat 60 and extends rearwardly from the body member 36 through a packing assembly 146 and then through another packing assembly 148 into the body member 24 and the chamber 34 therein. A sleeve member 150 is secured to the needle valve 144 by a pin 152 or the like and slidably projects within a hollow knob member 154 which is adjustably threaded into a cap 156. The cap 156 is turned onto a threaded portion 158 of the body member for closing the chamber 34. A piston assembly for openr ing the needle valve 144 when air under pressure is introduced into the passageway 14 is provided, which assembly includes an annular member 160 slidably disposed on the needle valve and having a tubular section 162 slidable over a reduced diameter end section of the sleeve member 150. A cooperable annular piston member 164 is assembled over the tubular portion 162 and secured thereon by a nut 166, and an `CJ-ring 167 is clamped between the

members

160 and 164 for sealing engagement with the wall of the chamber 34. A relatively heavy compression spring 168 is provided between the piston assembly and the cap 156 for yeldably biasing the piston assembly toward the left as viewed in Fig. l for permitting closing of the needle valve 144. A relatively light compression spring 170 is provided between the end of the knob member 154 and the sleeve 150 for yieldably biasing the needle valve 144 toward engagement with the valve seat 60.

It is to be noted that when air under pressure is admitted to the inlet passageway 14, the piston assembly is forced toward the right against the action of the spring 168 so that the end of the tubular section 162 of the piston assembly engages the enlarged portion ofthe sleeve member 150 and causes the needle valve 144 to be shifted to an open position. However, the strength of the relatively heavy spring 163. is such that opening of the needle valve 144 will be delayed after initial entry of air under pressure into the passageway 14 until the air pressure at the orifices 66, 86 and 88V has been built up substantially to the desired levels for proper operation or spraying action. Furthermore, when the air supply to the passage- Way 14 is cut oft, the relatively heavy spring 168 substantially instantaneously shifts the piston assembly back towards the left to permit closing of the needle valve 144. Actual closing of the needle valve is accomplished by means of the spring 178 which is strong enough to shift the needle valve toward the left as viewed in Fig. l s ubstantially instantaneously when the air supply is cut of but which is not as strong as the relatively heavy i spring 168 so that the needle valve is not forced against a second knob member 132. The knob member 13.2 has intermediate threaded portions 134 turned into an internally` threaded bore 136 in the knob member 110. AnV outer end portion 138 of `the knob member 132 is enthe valve seat with an undue force Which might cause injury to the valve or valve seat.

A brief rsum of the operation of the spray gun structure described above is as follows. The spray gun is, of course, first connected to a suitable source of air under pressure preferably having a shut-off valve in the supply line and also to a source of material such as paint or the like to be sprayed. Then the air or any other suitable gas under pressure is admitted to the passageway 14. The air pressure in the supply line to the gun may, for example, be about pounds per square inch, but this passageways and orifices described above has become substantially stabilized. Then the piston assembly is shifted toward the right to open the needle valve 144 and spraying of the material begins as will beunderstood. yIf the operator observes that the material being sprayed is not properly atomized, the character of the atomization may be changed by adjusting the valve member section 98 so as either to open or restrict the apertures 92 as required. Then in the event the shape of the spray is not as it is desired, the operator may change the pressure of the air emerging from the fan orifices 86 and S8 by adjusting the valve 128 without changing the character of the initial atomization of the spray material. After a spraying operation has been completed the air is shut off from the passageway 14 and the needle valve 144 is substantially instantly closed in the manner described above so as to terminate the flow of the material being sprayed and prevent sputtering or dripping of the spray material.

While the preferred embodiments of the present invention have been shown and described herein it is obvious that many structural details may be changed without departing from the spirit and scope of the appended claims.

The invention is claimed as follows:

1. In a spray gun of the type described, nozzle means having first and second gas passageways therethrough for directing separate streams of gas against material sprayed from the nozzle means, a gas supply conduit having communication with both the first and second gas passageways, a compound valve mechanism between the supply conduit and the first and second gas passageways, a first valve-controlled opening between the supply conduit and the first gas passageway, said valve mechanism including first and second valve members with the first valve member operable to control the said first valve-controlled opening, and said first valve member having a second valve-controlled opening between the supply conduit and the second gas passageway, and said second valve member being movable toward and away from the second valve-controlled opening in said first valve member for controlling the passage of gas therethrough.

2. A spray gun, as defined in claim l, wherein said first valve controlled opening extends laterally of said supply conduit, said second valve controlled opening extending substantially axially of said supply conduit, and said valve mechanism including means for selective axial adjustment of said first and second valve members as a unit and relative to each other.

3. A spray gun of the type described comprising nozzle means having a passageway therethrough for material to be sprayed and first and second gas passageways therethrough respectively for directing separate streams of gas against material delivered from said first mentioned passageway, body means connected to said nozzle means, means providing gas supply passageway means through said body means and communicating with said first and second gas passageways, valve means between said supply passageway means and said first and second gas passageways for controlling independently gas fiow to said first and second gas passageways, said valve means including means defining a first valve opening between said supply passageway means and said first gas passageway, a first adjustably shiftable valve member cooperable with said first opening means and including means defining a second valve opening between said supply passageway means and said second gas passageway, and a second valve member cooperable with said second valve opening and mounted for shifting movement with and also for adjustment relative to said first valve member, another valve member extending into said first mentioned passageway for controlling ow of material to be sprayed therethrough, means providing a chamber in said body means communicating with said supplyA gas passageway means, said last mentioned valve member having a portion projecting to said chamber, piston means operably interconnected with said 1 last mentioned valve member portion for shifting said valve member to an open position when air under pressure is introduced into said supply passageway means, and resilient means disposed for biasing said last mentioned valve member toward a closed position for closing said last mentioned valve member when air under pressure is cut ot from said supply passageway means.

4. A spray gun, as defined in claim 3, wherein an abutment member is fixed to said last mentioned valve member portion, said piston being slidable with respect to said last mentioned valve member portion and said abutment Amember and also engageable-with said abutment member upon movement in one direction for opening said last mentioned valve member, said resilient means including a relatively heavy spring for substantially instantaneously shifting said piston in an opposite direction to permit closing of said last mentioned valve member when air under pressure is shut ofi from said supply passageway means, and relatively light spring means for substantially instantaneously shifting said last mentioned valve member without undue force toward a closed position.

5. A spray gun, as defined in claim 3, which includes a first adjustment member connected to said first valve member and adjustably connected to said body means, and a second adjustmentk member connected to said second valve member and adjustably carried by said first adjustment member, whereby manually shifting of said first adjustment member causes shifting of said first and second valve members as a unit and manual shifting of said second adjustment member with respect to said first adjustment member causes shifting of said second valve member with respect to said first valve member.

6. A spray gun of the type described comprising nozzle means having first and second gas passageways therethrough respectively for directing separate streams of gas against material, sprayed from the nozzle means, body means secured to the nozzle means, gas supply passageway means in said body means including a bore communicating with said first and second gas passageways, and valve means disposed for controlling independently gas flow from said bore to said first and second passageways, said valve means comprising means defining a first valve opening extending laterally from said bore and communicating with said first passageway, a first adjustable shiftable valve member in said bore cooperable with said first valve opening and including means defining a second valve opening communicating with said second passageway, and a second valve member cooperable with said second valve opening and mounted for shifting movement with and also for adjustment releative to said first valve member.

7. A spray gun, as defined in claim 6, wherein said bore extends from an inner end portion thereof which communicates with said first and second gas passageways to an outer end thereof opening at a peripheral surface of said body means, which spray gun includes a first adjustment member threaded into an outer end portion of said bore and connected with said first valve member,

and a second adjustment member adjustably threaded into said first adjustment member and connected with said second valve member so that upon turning of said first adjustment member relative to said body means said first and second valve means will move as a unit and so that upon turning of said second adjustment' 7 Y Y' 8 portions disposed beyond the body means for facilitating 1,609,465 Day Dec. 7, 1926 manualiV adjustment of said valve members;A 1,660,359 Schneider Feb. 28, 1928 1,962,911 Roselund June 12, 1934 References Cited in the lelorthis patent'` 2,252,200 Plummer n Aug, 12, 1941 UNITED STATES PATENTS 5 1,321,014 Day Noi/4,1919 FOREIGN PATENTS 1,369,520 Day Feb. 22, 1921 682,699 Great Britain Nov. 12, 1952