US2583706A - Spray gun nozzle assembly - Google Patents

Description

Jan. 29, 1952 l. s. PRESCOTT SPRAY GUN NOZZLE ASSEMBLY 2 SHEIETSSHEET 1 Original Filed Jan. 5, 1948 b a R m E r VP m I C a 5 L ON BY Caz/M14070, fzZn-m Midi? Jan. 29, 1952 1. s. PRESCOTT ,7

SPRAY GUN NOZZLE ASSEMBLY Original Filed Jan. 5, 1948 2 SHEETS-SHEET 2 A .w m E W M W W d \N m h 5 $4 I M a QM R Q AWN .QVQNR Q I Q 8 00.

.W@ i E: E :EEEE: E2; 9. w Q N@ O@ Q @n 0w ed e of the plane wall of said partition which abuts the end of tube I2 forming the seat for valve 33. The valve rod I6 is also provided with an extension 34 of reduced diameter which passes outwardly through the opening 30 and carries at its outer end another or secondary valve 35 adapted to control the flow of spray liquid through the central opening 36 in the whirl plate 26. The maximum diameter of the secondary valve 35, which is that of its substantially cylindrical seat engaging portion 31, is slightly smaller than the diameter of opening 30 in partition 29 so as to facilitate assembly and disassembly of the spray gun. The valve operating rod I6 also carries a centering guide member 38 fixed thereto adjacent the main valve 33, which member is generally triangular in shape as indicated in Fig. 6, the apices of said member being rounded and having sliding engagement with the bore of tube I2 so as to center the valve rod I6 in said bore, while the open spaces between said apices enable the spraying solution to flow freely past said member.

'The whirl plate 26, the details of which are shown in Figs. 2,3 and 4, consists of a relatively thin annular rim 39 of sheet metal lying in a plane perpendicular to the axis of the'central opening 36, and a hollow cylindrical boss 46 which is fixed to the inner periphery of the rim 39, as by the clinched connection indicated at 4|, and projects axially inwardly from the rim into the chamber 3I oi nozzle body 24. The axial length of the boss 49 and its inside diameter are such that the cylindrical portion 31 of secondary valve 35 slidably engages the bore of boss 40 so as to close the central opening 35in the whirl plate both when the main valve 33 is closed and when it is within a predetermined distance of itsseat in partition 29, at which times the spray material is discharged from the gun in the form of a relatively wide angle, foglike spray of relatively short carrying distance, created by passage of the spray material through only the tangential openings 42 of the whirl plate (next to be described). The boss 48 is short enough, however, to permit withdrawal of the secondary valve 35 when the main valve 33 is withdrawn further from its seal than the position indicated in Fig. 2, at which time the secondary valve 35 will occupy a position such as that indicated in broken lines in Fig. 2, and the spray liquid will pass through both the central opening. 36 and the tangential openings 42 of the whirl plate and will be discharged as a more concentrated conical spray capable of carrying to a greater distance.

28 consisting of an annular rim portion 45 lying parallel to the rim 39 of the whirl plate and spaced therefrom by the gasket 2?, an elongated nose portion 46 which projects outwardly from the rim portion 45 through a central opening in the nozzle cap 25, and a bushing 41 seated in the nose portion 43, the bore of which bushing 45 and 46 are usually made of a softer metal,

such as brass.

In order to increase the effective distance or spraydischarge from the gun, the bore of bushing 4'! tapers or converges'toward the discharge end Inthe form of whirl plate shown in Figs. 2,

3 and 4, the tangential openings 42 which impart the whirling movement to'thespray material as it passes from the chamber 3| to the nozzle disc 28 are formed by cutting the rim. 39 along radial lines, as at 43 in Fig. 3, and then pressing arcuate sections of said rim outwardly. (to the right as v ewed in Figs. 2 and 4) to form trough-like conduits 44 of varying depth with respect to the plane of rim 39, said conduits terminating in the substantially semicircular openings 42 which lie'in planes perpendicular to the rim' 39 passing through the'radial lines 43. Any suitable number of tangential openings may be formed in the whirl plate, although the preferred arrangement comprises four such openings as illustrated in Fig. 3.

Cooperating with the whirl plate to form the spray discharge from the gun is the nozzle around the rod I6 between the gland I4 andnut' throughout the major portion of its length, as indicated at 49, andterminates in a relatively short section 50 of uniform diameter. The straight section 50 may vary in diameter from '1 s" to 1 6-; and since the bushing 41 is replace able, the desired size of spray discharge orifice may be readily obtained by simply selecting a bushing. wherein the section 50' is of the proper diameter. It has been found that exc'ellent'results are-obtained by limitingthe length of the straight section 58 to approximately A in a disc wherein the nose portion 46 projects approximately .6 from .the rear face of the rim. portion.45, and'by tapering the bore section 49 at an angle of approximately 10.

The whirl plate 26, gasket 27 and nozzle disc" 28 are held in properly assembled relation with respect to one another and to the nozzle body 24 by the nozzle'cap 25 which has an internally threaded rim 5| adapted to thread onto the externally threaded outer end of nozzle body 24,.- J and an annular wall 52 adapted to engage the.

rim portion 45 of the nozzle disc and having a central opening through which the nose portion 46 of said disc projects. When the elements of the nozzle are assembled, the annular space 53 between the whirl plate and nozzle disc consti' tutes a whirl chamber into which the spray ma terial issuing from the tangential openings 42 dischargesand in .which it sets up the whirling motion that produces the fog-like characteristic of the spray.

Movementof the-main and secondary valves 33 and 35 from and to their respective seats is controlled'by rotation of the handle ll which is fixedto the end of the valve operating rod I6 opposite that carrying the valves, rotation of thehandle I! being converted into longitudinal movement of the rod l5 and valves 33 and. 35 by means of a threaded connection between the handle and an extension 54 of the packing nut I5.

As shown in Fig. 2, the valve rod It extends outwardly of the gun body member II through the packing gland I4 and packing nut I5, including the latters extension 54, and terminates in a threaded portion 55 to which the handle I1' is fixed. A suitable packing 56 is provided I5 so as to prevent leakage of the spray material from the body'member II outwardly along the rod, and the packing gland I4 is provided with a locking screw 51 ior preventing rotation of pack-- ing nut. l relatlvelyto the gland once the-pack ing' 56 hasbeen properly compressed. The outer portion of the handle I! is provided with a smooth bore 58 of a diameter such as to receive thethreaded portion 55 of the rod 15, while the inner portion of. the handle is recessed to receive an internally threaded ferrule 59 which surrounds and has threaded engagement with the extension 54 of the packing nut 15. Although the ferrule 59 may be fixed to the handle I! in any suitable manner, the embodiment disclosed comprises a handle of hard rubber or other plastic material molded around the shank of the ferrule 59 which is preferably provided with circumferential ridges 60 to prevent axial displacement of. the two elements. It will be understood that the pitch of the cooperating threads of ferrule 59 and packing nut extension 54 is great enough to enable relatively rapid opening and closing of the valves, but also small enough to permit the proper degree of adjustment thereof for the difierent spraying conditions desired and to maintain the valves in any adjusted position notwithstanding the axial pressure exerted by the spray material.

The handle I7 is fixed to the valve operating rod. Why a pair of nuts GI and 6 2, the nut 6! being threaded all the way on the portion oi the rod and, with a suitable washer 63, serving asv a stop for the base of ferrule 59 when the end of. the rod is passed through the bore 53 of the handle, while the nut 62 and its washer S ll are housed in a recess 65 in the outer end of the handle and are screwed up tight against the base of said recess so as to clamp the portion of the handle surrounding the bore 58 between the two nuts. With this construction, rotation of the handle [5 and its resulting axial movement due to the threaded engagement between the ferrule 58 and packing nut extension 54 produces axial movement of the valve operating rod and the valves 33 and 35 carried thereby. In order to positively limit movement of valve rod It in valve opening direction to a desired maximum, the central portion of the rod located in body member H may be provided with a transverse pin 66 which. is adapted to come into engagement with. the inner face of packing gland 14 when the valves are fully opened.

Referring now to the construction by which the spray gun of the present invention is adapted to be adjustably mounted on a spray boom or other support, the supporting tube 43. is threaded into the body member ll intermediate its ends with the axis of the. wheat right angles to that of the body passageway the. bore of the tube'being. in free communication with said passageway for supplying spray liquid. to the latter under pressure. The other end 01 tube it is also externally threaded over a substantial distance for engagement with cooperating threads formed internally of the portion iii (the upper portion as viewed in Figs. 1 and 2) of mounting not It. The exteriorof portion $1 of the mounting nut is likewise threaded to receive the internally threaded end of the hollow cylindrical body of the packing nut 29,. while the closed end portion 65 of the packing nut frictionally engages the smooth cylindrical portion of support ing tube 18 intermediate its threaded ends. .A

suitable leak-proof packing 68 fills the space be tween the closed end portion. to of the packing nut and the adjacent end of the portion 5'! of the mounting nut, and is tightly compressed in. said space around the tube l8 so as. torprevent leakage or spray liquid throughthe-gun adjusting threaded connection between the-tube l8- and mounting nut'l9. The frictional engagement with the tube. l8 resulting from compression of the packing. 63 in this; manner also serves to maintain the gun in any position to which. it may be. adjusted by rotation of tube 58 relatively to mountingnut l3.

As shown best in Fig. .2, the body of mounting nut. I9 is provided with a frusto-conical recess l0, having a minimum diameter greater than thatof the threaded portion 61, into which the end of tube l8projects as the latter is threaded downwardly as viewed in Fig.2. The outer portion of. recess 101s threaded to receive. the similarly tapered and threaded end of a, nipple 2| or other suitableelement forming part of the spray boom .22or other supporton which the gun is adapted to be mounted, the conical taper of the cooperating threaded elements facilitating a liquid-tight connection thereb'etween.

When'the spray gun is assembled. and mounted in the manner indicated in Figs. 1 and 2, the spraying solution .is supplied under pressure to the interior of theboom or support 22 in any suitable manner, as, for example, in my previously mentioned Patent No. 2,444,367. The solution passes upwardly, as viewed in the figures, through the nipple 21, mounting nut 19 and tube 1 8 into the passageway 23' of the body member I l and thencethrough the gun tube l2 to the nozzle assembly. If the handle I! is so rotated with respect to the threaded extension 54 of the packing nut l5 that the valves occupy the positions illustrated in Fig. 2, wherein the main valve 33 is partially open but the secondary valve. 35 is still closed, the spray liquid will flow through the opening 30 in the partition 29 into the chamber 3!, then through the tangential openings 42 of the whirl plate 25 into the whirl chamber 53, and

finally through the converging and straight portions 49 and 50 of the orifice-forming bushing 4! of the nozzle disc 28, issuing from the orifice 43 in the form of a wide angle, fog-like spray of relatively short carrying distance. If the handle I l is further adjusted so as to withdraw the secondary valve 35 to the position indicated in broken lines inFig. 2', the spray solution will then pass through the central opening 36 in the whirl plate as well as through the tangential openings 42, with the result that the spray issuing from the orifice 48 is more concentrated and carries to a greater distance than when only the main valve 331s open. The characteristics of the spray may, of course, be varied over a relatively wide range by suitable adjustment of the positions of the valves between the limits permitted by the positions of the transverse pin 66 and the valve seats formed by the partition 29 and boss 411i.

There is thus provided by the present invention a new format spray gun which embodies a number of improvementsover similar devices heretoforeavailable; For example, by providing the packing nut of..the=body member with a threaded extension cooperating with. a similarly threaded portion of. the handle, the valve adjusting mechanism is located entirely outside of the body member and out of contact with the spraying solution, thereby preventing corrosion and freezing of the threaded members by which the valve operating rod is moved. The combination of the body supporting tube, mounting nut and associated packing. nut is. also an improvement over prior devices of. the. same general type. in that it provides-a leak-proof means for so mounting a spray gun on a support that the direction of the spray can be readily adjusted,'and once the adjustment has been made, the gun will remain in the desired position without the necessity for manual support or the use of locking means which have to be unlocked in order to make the adjustment. Another feature of the present invention is that the various elements of the gun are easily assembled and disassembled, so as to facilitate manufacture and repair, and the majority of the parts are individually replaceable. Further improvements reside in the novel form of nozzle disc which increases the efiective distance of spray coverage with the same pressure on the spray material, and in the inclusion of the removable orifice-forming bushing which both prolongs the life of the nozzle assembly. and also makes it possible to change the size of the orifice by simply replacing the bushing. The nozzle assembly also includes an improved form of whirl plate of simple, inexpensive construction which is so designed as to also form the valve seat for the secondary valve.

While only one specific form of spray "gun embodying the invention has been described and illustrated in the accompanying drawing, it will be obvious that the invention is not limited to the exact structure shown, and is equally adaptable to multiple nozzle spray guns as it is to the single nozzle gun illustrated. Various changes which will now suggest themselves to those skilled in the art may be made in the form, details of construction and arrangement of the parts with out departing from the inventive concept. Reference is therefore to be had to the appended claims for a definition of the limits of the invention.

This application is a division of abandoned application, Serial No. 549, filed January 5, 1948.

What is claimed is:

1. In a spraying device, a spray nozzle assembly comprising a whirl plate having a central opening and a plurality of tangentially directed openings circumferentially spaced about the central opening, a nozzle disc spaced from said whirl plate having an orifice through which the spray is discharged from the nozzle assembly, a gasket interposed between the peripheries of said whirl plate and nozzle disc, and means for holding said plate, disc and gasket in assembled relation with the orifice in said disc coaxial with the central opening in said plate,said disc having an annular rim portion lying in a plane perpendicular to the axis of the spray discharge orifice, an

elongated hollow nose, portion,,projecting oua 2. .A spray nozzle assembly according to claim;

wherein the orifice-forming bushing has a' bore which decreases in diameter toward the discharge end thereof and terminates in a relatively short section of uniform diameter.

3. A spray nozzle assembly according to claim 1 wherein the orifice-forming bushing is made of a harder metal than theremainder of said nozzle disc and is pressed into place in the nose portion of said disc with a friction fit so as to be replaceahle.

4. In a spraying device of the type embodying a body member having a passageway therein, a nozzle assembly connected to one end of said body member means for supplying spray materialto said passageway and valve means for controlling the flow of spray material from said passageway to said nozzle assembly, a spray 'ber nozzle assembly comprising a Whirl" plate having a central opening and a plurality of tangentially directed openings circumferentially spaced about the central opening, a nozzle disc spaced from said whirl plate having an orifice through which the spray is discharged from the nozzle assembly,

a gasket interposed between the peripheries of said whirl plate and nozzle disc, and means for holding said plate, disc and gasket in assembled relation with the orifice in said .disc coaxial with the central opening in said plate, said whirl plate having an annular rim lying in a plane perpendicular to the axis of the central opening therein,

the tangentially directed openings being formed in said rim by outwardly pressed portions thereof each of which is separated from the remainder of the rim along a radially extending line, and a hollow cylindrical boss fixed to the inner periphery of said rim and projecting inwardly therefrcm' passageway of said body member, a nozzle body element threaded at one end to the other endof said nozzle supporting element, a centrally apertured transverse web formed integrally with said nozzle body element intermediate the ends thereof and forming a valve seat, a centrallyapertured nozzle cap threaded to the other end of said body element, spray forming means interposed between said cap and the end of said body "element including a centrally apertured member forming a second valve seat, valve means for controlling the flow of liquid through said nozzle including a valve operating rod passing through the passageways in said nozzle supporting ele' ment and body member and extending outwardly of the latter at the end thereof opposite that to which said nozzle supporting element is 'connected, said valve operating rod also extending 7 opening, and a hollow cylindrical member fixed in the central opening in said plate and forming the valve seat for the outermost valve carried by said valve operating rod.

ISAAC S. PRESCOTT.

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

UNITED STATES PATENTS Number Name Date 1,328,721 Crummey Jan. 20, 1920 1,343,780 Hull June 15, 1920 1,728,455 Taylor et a1. Sept. 17, 1929 2,118.194 1.938

Hukari i May 24,

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