US2050368A - Spray nozzle - Google Patents

Description

G. L. NEELY SPRAY NOZZLE Aug. 11, 1936.

Filed Feb. '26, 1934 fi eor'g Leonard Neely INVENTOR.

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ATTORNEY v Patented Aug. 11, 1936 UNITED STATES PATENT OFFICE 4 Claims.

This invention relates to spray nozzles and particularly but not necessarily to those in which a fluid under pressure is utilized to aspirate a liquid from a container and then atomize it to form a 5 finely divided spray or mist. Such a one is dis closed in my copending application Serial Number 348,164, filed March 19, 1929, and on which Patent No. 1,948,533 issued February 27, 1934 and of which this application is a continuation in part.

In small spray devices, particularly those used for atomizing liquid insecticides by means of a pressure fluid such as water from the usual piped supply, it is particularly diflicult to provide a simple and cheaply manufactured construction which will maintain the continued accurate and close alignment of the various parts forming the nozzle. It has been found by extensive tests that an annular converging conoidal jet of water, for example, if directed through suitable passages so no as to give it a vortical motion, will cause a reduction of pressure at its apex or converging point. If a suitable axial passage is provided from this apex or converging point to a liquid supply, the said liquid will be aspirated and thoroughly mixed with the water, and the resulting mixture will be dispersed into a finely divided cone shaped spray or mist. Under some circumstances, however, it is possible to feed the liquid under a positive head, so that the aspirating action may be subsidiary 90 to the diluting, atomizing and dispersing actions.

The dimensional factors governing these actions, however, are quite critical, particularly the thickness of the annular converging conoidal jet, the degree of vortical motion or whirling and the resulting angle of divergence of spray from the nozzle tip.

The devices heretofore utilized for maintaining these shapes and clearances have been made with two separately threaded members, the outer mem- 40 her or shell being provided with a conical recess,

and the inner member fitting into the recess and separately threaded into the base or support member, as in my application above cited. Thus the concentricity of the. two elements, which de- 45 termines the parallelism of the fluid passage walls has been dependent upon two sets of threads, which have been found entirely inadequate to maintain the close tolerances, on the order of two 'or three one-thousandths of an inch, which are essential to proper operation.

Another feature which has been both difiicult and expensive to provide is the means for giving the conoidal fluid jet a whirling or vortical motion. Cutting helical passages or grooves in a cylindrical 55 element is easily and quickly done, but a simultaneously helical and conical machining operation requires elaborate and expensive equipment.

It is an object of this invention to provide a spray nozzle in which the elements defining the conoidal converging passage may be permanently 5' and accurately fixed together during the manufacture of the nozzle.

Another object is to provide a tip for a spray nozzle in which the spacing and aligning means defining the fluid passages are entirely independl ent of the means for holding the nozzle in assembled relation, and which spacing means are not subject to change in shape or clearance during assembling operation, or cleaning.

Another object is to provide a spray nozzle assembly which may be fabricated with a minimum of machining operations and in which those machining operations required are easily and simply made.

Another object is to provide a spray nozzle tip in which the means for providing a vortical or whirling motion in the fluid passages are formed by straight cuts or shaping operations, thereby avoiding the expense of conical helix generation.

Another object is to provide a tip for a spray nozzle that is separable as a unit from the body of said device, and which may be accurately and cheaply duplicated for quantity production.

These and other objects and advantages will be more fully apparent from the following description of a preferred embodiment of this invention, and from the accompanying drawing, which supplement the description and form a part of this specification. In the drawing:

Figure 1 is a longitudinal sectional view, to an enlarged scale, of a spray nozzle embodying this invention, and in which the tapered plug member is crimped into place within the closure member.

' Figure 2 is a side elevation of the tapered plug member shown in Figure 1. 40

Figure 3 is an end elevation of the tapered plug member shown in Figure 2, illustrating the angularly directed slots which give a vortical motion to the conoidal fluid jet.

Figure 4 is an approximately full scale side elevation, partly in section, showing an alternative method of assembling the nozzle tip to the body, and also illustrating the nozzle assembly in place upon a receptacle from which liquid is to be withdrawn, mixed or diluted and atomized.

Referring to the drawing and particularly to Figures 1 and 4, the body of the nozzle is generally designated in, and in this example is provided with an offset pressure fluid passage I I, extending longitudinally from a threaded inlet l2, to a recess or chamber I3. A second passage I4 extends axially partly through the body I0 and communicates with a threaded liquid inlet connection I5, which is illustrated as being on the side of the body I0. Bore I2 may be connected to any fluid pressure supply, in this example a garden hose, and liquid inlet I5 may be connected by any suitable conduit to a liquid source such as a receptacle for a concentrated spray material, as will be more fully explained and described below.

A closure or cap I6 is secured to the outlet end of body I0 by means of a threaded union nut I'I cooperating with corresponding threads I8 on body I0. Closure I6 is provided with a tapered bore I9, which communicates with a cylindrical outlet passage 20. The included angle of the bore I9 at the outlet and the angularity of grooves 26 have been found to be governing factors, and, when using water as a pressure fluid and aspirating and atomizing liquids, the included angle A of the tapered plug is preferably about 35 and the angle B between an axial line and each groove 26 is preferably about 15. With these dimensions the resultant angle C of the spray will be between 15 and 20 degrees. A greater angle of spray will result from an increased value of either of the above angles A or B and will give poor aspiration. A smaller angle of spray gives poor atomization. Bore I9 is preferably finished by the use of a tapered reamer, which permits accurate duplication with smooth bore finish.

A tapered plug generally designated 2I is mounted within the bore I9 of cap I6, and the larger end of bore I9 may be crimped or beaded over as at 22 to hold the plug in place and aligned with the bore. This is a particularly desirable construction if the nozzle tip is to be used in a garden sprayer, for example, where relatively unskilled operators may dismantle the whole device for cleaning. In case of oil burners and the like, however, where skilled mechanics would ordinarily do this work, the crimping or beading is not required.

Plug 2I is illustrated in Figures 1, 2 and 3, and preferably comprises a stem 23, of generally spherical shape adapted to seat into the bevelled outlet 24 of liquid passage I4 in body ID. The major portion of plug 2I, however, is enclosed within bore I9 in cap IS. The base or skirt portion 25 is of the same taper as bore I9 and fits it closely, thereby constituting the aligning means between the plug 2I and the bore I9. Angularly directed grooves 26, best illustrated in Figure 3, and preferably not less than six in number, are cut in the skirt 25 and serve to give the essential vortical or whirling motion to the pressure fluid passing around plug 2I. These grooves may be truly helical but it has been determined that, if they are disposed as illustrated in Figure 3, slightly displaced circumferentially from axial planes through plug 2I, they may be made by a simple straight shaping operation, substantially parallel to the tapered outer surface of skirt 25, thereby effecting considerable savings in machining costs.

Intermediate the ends of plug 2I may be located a circumferential groove 21, which appears to act as an equalizing chamber, so that the fluid passing outwardly between bore I9 and the tapered and inwardly spaced surface of the plug tip 28 will be spread out as a smoothly flowing sheet instead of, for example, six independent streams from the six grooves 26 of the skirt. As just described, the tapered tip 28 of plug 2| is. spaced inwardly by the lands 29 between grooves 26 from bore I9, preferably about 0.007 inch, plus or minus 0.002 inch, when using water as a pressure fluid, and when aspirating and atomizing concentrated commercial liquid insecticides.

The closure or cap I6 illustrated in Figure 1, is secured to the body ID by means of the threaded nut IT, as stated above, and the joint is made liquid tight by a resilient composition or rubber gasket 30. The force exerted by screwing nut Il onto threads I8 first compresses gasket 30 and then seats stem 23 tightly into the bevelled outlet 24 of liquid passage I4. This latter action forces plug 2I tightly into bore I9, if it has not already been crimped therein as at 22, and the lands 29, contacting with bore I9 over their full faces and for a considerable axial length, serve to perfectly align and space the tapered tip 28 in the smaller end of bore I9. This arrangement completely eliminates any possibility of misalignment of those parts, the threaded nut I'I serving only to make tight the two fluid joints, at 39 and at 23, and to urge the plug 2I and cap l6 into still more perfect union.

A strainer 3I may be inserted in chamber I3, or, as illustrated in Figure 4, may be placed in the bottom of threaded inlet I2, to prevent dirt and debris from being carried into the grooves and passages of the nozzle tip.

As an alternative to the removable joining together of the nozzle tip and body by a union nut I1, as in Figure 1, the construction diagrammatically illustrated in Figure 4 may be employed, in which the closure or cap I6 is flanged outwardly as at 32, and a corresponding flange 33 is formed on body I0. These flanges are preferably spaced apart slightly, as illustrated, by the stem 23 of the tapered plug seating in bore 24 (Fig. 1) and are enclosed and sealed by a circumferential ring 34, which is crimped or formed over the outer faces of the flanges 3| and 32. This obviously forms a tight and permanent union between the body I0 and cap It, so that the desirable location of wire mesh or perforated metal strainer 3I is at the bottom of threaded inlet bore I2.

Figure 4 also illustrates a. convenient arrangement of a receptacle 35 as for a liquid insecticide, detachably secured to body I0 by a threaded cap 36, and into which a conduit 31 depends. The upper end of conduit 31 com municates with the axial liquid inlet passage I4 of body I0 (Figure 1) and allows liquid 39 to be aspirated from the receptacle 35, or, if the receptacle were to be inverted, permits the liquid to flow to the axial liquid inlet I4, under a positive gravity head through axial bore 4I in plug 2| so that it passes into the converging jet of pressure fluid and is atomized into spray. My copending application above cited discloses means for obtaining a constant flow of liquid 39 from receptacle 35 in the position shown, regardless of the depth of liquid therein, thereby providing a constant mixture-ratio with the pressure fluid admitted through hose 38 to the conoidal jet.

In operation, the pressure fluid, which may be water in the case of an insecticide sprayer, or a gas such as air or steam in a burner nozzle, is admitted to body I0 through hose 42 threaded into inlet I2 and passes through bore II into chamber I3, from which it is admitted into the plurality of helical or angularly directed passages formed by the cooperation of grooves 26 and the bore I9 of cap I6. Thus the pressure 7 fluid is given a whirling or vortical motion, which is preferably smoothed out or made into a uniformly flowing sheet by circumferential groove 21 and finally passes out of the nozzle over the smoothly tapered surface of tip 28. It will be found that the converging jet thus formed does not follow the cylindrical bore or outlet passage 26 of the cap [6, but leaves it cleanly at the juncture of 29 with the tapered bore I9. This action is facilitated by the projection of the end of tip 28 into the cylindrical bore or outlet 28. After leaving the nozzle the streamer jet reaches a minimum diameter and then diverges again, forming the angle C (Fig. 4). It has been found by many tests that the angle C of the spray should be between 10 and 25 degrees, and, for best operation is substantially 15 degrees. This may be determined by several factors, the principal ones being (1) the included angle of the tapered tip 28 and (2)' the vortical whirl produced by grooves 26 in skirt 25. If the angle of tip 28 is substantially degrees, the angle of grooves 26 with an axial line along the face of the skirt may lie between 13 and 16 degrees for satisfactory operation. The extreme tip or end 48 of plug 2| is preferably flat or at least blunt, to facilitate the formation of a reduced pressure in the axial bore at in said tip, through which latter the liquid 39 from receptacle 35 or its equivalent may pass into the converging conoidal jet of pressure fluid and be mixed and atomized in the resulting spray.

Once determined, the clearances, concentricity and divergence of the spray are readily duplicated by the construction disclosed, and, what is more important, these factors are not disturbed, as the plug 2! ma be securely crimped into bore H), as disclosed above at 22, or, if not permanently fastened therein, will be so accurately guided by the lands of base or skirt 25 contacting the bore 19 that misalignment is hardly possible.

Although a specific example embodying this invention has been described and illustrated, it is to be understood that the invention is not limited to the particular features disclosed, and all such modifications and changes as come within the scope of the following claims are embraced thereby.

2-. A spray nozzle comprising a body, a fluid chamber in said body, a closure member for said chamber provided with a tapered bore, a tapered plug disposed within said bore, the base of said plug fitting said bore closely and provided with substantially helical grooves and lands constituting fluid passages, a circumferential groove intermediate the ends of said plug, the remainder of the tapered portion of said plug being of smooth configuration and spaced from said bore solely by said lands, and an axial liquid passage in said plug.

3. A spray nozzle assembly comprising a bod provided with a recess, a fluid passage in said body communicating with said recess at one side thereof, a liquid passage in said body coaxial with said recess and communicating therewith through a beveled seat, a tip for said nozzle constituting complementary means for producing an annular uniformly converging conical passage communicating with said fluid passage, said tip provided with an axially projecting member received in said beveled seat, said member and tip being provided with a passage coaxial with said conical passage, and means for securing said nozzle tip to said body.

4. In a spray nozzle including a closure cap provided with a converging tapered bore and means for admitting a pressure fluid to said bore, a tapered plug provided with a grooved base at its larger end, a circumferential groove intermediate its ends, and a smoothly tapered tip, said tip conforming to the taper of said bore and spaced therefrom solely by said base, and an axial bore in said plug.

GEORGE LEONARD NEELY.

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