US 3163362 A
Description (OCR text may contain errors)
M. R. M FEE Dec. 29, 1964 SPRAY DEVICE HAVING OUTER AND INTERIOR TUBULAR CONSTRUCTION Filed Feb. 4, 1963 INVENTOR.
4; 1?. )dcFL-E United States Patent 3,163,362 SPRAY DEVICE HAVING GUTER AND INTERIOR TUBULAR CONSTRUCTKGN Max R. McFee, 306 Maple Ave, Springdaie, Ark. Filed Feb. 4, 1963, Ser. No. 255,796 3 Claims. ((11. 239-401) This invention relates to the construction of a spray nozzle using only the atomizing and driving force of low pressure compressed air for applying very line and, if
desired, concentrate sprays to delicate articles and surfaces without injury to such materials and surfaces.
l-leretofore such air operated spray guns have largely been made for producing a penetrating spray. Characteristic of such spray guns is one in which air is introduced from a direction outside of the material to be sprayed. This has resulted in concentration of the material being sprayed, giving it an abrasive, cleaning action.
In contrast to such prior art the mechanism of this present invention introduces compressed air from the inside outwardly into the annular converging jet or spray liquid which has passed through certain passageways to provide it with a vortical motion. In other words, the compressed air is liberated within and interiorly of the converging jet of spray liquid. In the device of this present invention, there is provided a substantial mixing of air with the liquid to be sprayed and this is initially established interiorly of the tip of the nozzle and subsequent thereto additional'mixing is elfected outside of the tip of the nozzle. The net result is that the liquid tobe sprayed is broken into extremely fine spray droplets and these are evenly diffused throughout the carrying air blast in such a manner that no injury results to delicate plants even when the nozzle is held fairly close to such surfaces.
A further object for which the nozzle of the present invention is constructed is to provide means of obtaining the extremely fine atomization described above with minimum pressure, since compressed air at high pressure may be dangerous if confined in a spray liquid tank which necessarily oxidizes somewhat over a period of years. To prevent such dangerous conditions, the nozzle of this improved device secures satisfactory atomization at only two sea level atmospheres; that is, pounds gage pressure per square inch. Thus at sea level the load'on the tank surfaces is only 15 lbs. p.s.i. with 30 lbs. pressing outwardly and 15 lbs. atmospheric pressure (actually 14.69 lbs) pressing inwardly.
A still further feature of the nozzle of this improved device is to provide a simple mechanism that will be trouble free and easy to produce and operate. The spray adjustment is made with the operators fingers, from the exterior of the nozzle and this adjustment can be performed even when the spray device is functiouing. Only two seals are necessary for the nozzle proper and for its cut-off, and these are simple 0 rings which have a long life, do not require tightening, and are easily replaced.
A still further feature of the present invention relates to a modificatiorlof the structure hereinbefore identified.
In this modification the ports for the admission of liquid:
FIG. 1 is a lengthwise cross sectional view of one satisfactory form of the device in which diagonally exice tending ports provide for a whirling or vertical movement of the liquid to be sprayed so that air is released in the mixing chamber in the center of such vortical move ment, the slots forthe release of liquid to be sprayed being formed in the exterior wall of the body next adjacent the nozzle wall;
FIG. 2 is a side elevation of the body providing the whirling effect, removed from the outer casing, and in which body the slots are formed for efieoting the whirling motion of the liquid to be sprayed;
FIG. 3 is a top view looking down on the whirl body shown at FIG. 2;
FIG. 4 is a view of a modification of the structure shown in FIG. 1 according to which the liquid to be sprayed is introduced into the mixing chamber through spiral ducts formed in the inner wall of the bore of the element through which the internal tube extends for the introduction of air to the mixing chamber. In this view the nozzle is shown as projecting downwardly;
FIG. 5 is a view of the whirl member of FIG. 4 removed from the casing and nozzle and looking upwardly into the ports from which the liquid to be sprayed is released and also upwardly at the outer end of the tube for discharging air;
FIG. 6 is a side elevation of the whirl member illustrated in FIG. 4 looking at its exterior;
FIG. 7 is an enlarged vertical central sectional View of the whirl body shown in FIGS. 4, 5 and 6 illustrating the spiral duct in the wall of the whirl body shown in FIG. 4; and
FIG. 8 is a bottom view looking upwardly at the whirl body shown in FIGS. 5 and 6 and somewhat enlarged.
Referring in detail to the several figures illustrated in the drawing, FIG. 1 is a lengthwise cross sectional, view of one form of the device in which the nozzle 1 projects upwardly and the intake pipes for the introduction of air and liquid to be sprayed are at the opposite or lower end. At the upper end of the device shown in FIG. 1 and just within the outlet end of the device is a tube 2- which terminates at the lower side of the mixing chamber 3 whereby air discharged from the tube 2 serves to mix air with the liquid furnished to the mixing chamber 3 from the ducts 4. Liquid to be mixed with the air is fed to the ducts 4 through lateral discharge passages 5 leading from space immediately surrounding the tube 2. The whirl body which provides for a vertical discharge of liquid to be sprayed extends from the mixing chamber downwardly as seen in FIG. 1 to the lowerend of an outer casing 7 and this whirl body is identified at 8 in FIG. 1. An O-ring 6 is shown as encircling the'wh-irl body 8 and the O-ring serves to seal off and prevent any passage of fluid between the whirl body 8 and the casing 7. I The lowermost end of the tube 2 is encircled by a washer 10, preferably of rubber, which is adapted to seat against the lower end of the whirl member 8 when the air tube assembly, composed of the tubes 2. and 11, and the washer 10, is moved upward, thus closing the. gap between i which air is introduced into the tube 2;
the seating surface on the whirl member and the washer 10, and thus stopping liquid flow through the nozzle. The lowermost end of the tube'Z is tightly sealed to the upper and innermost end of a larger tube 11 through end of the outer casing 12 is a stufi'lng box 16- through which the tube 11 projects. This stufling box 16 is screw threaded to the exterior ofthe casing 12 and within the lower end of the casing 12 there is a ime'talringld to: permit removal of the entire air tube assembly-consisting of parts 2, I0 and 11. Just above the ring 14there is a 7 smaller ring 13 whichis permanently affixed to the iiitcrior of the casiugIZ. Immediately below the 'ring14 is an O-ring of rubber 15 to prevent leakage'o-f fluid between the tube. 11 and the stufling box 16.
At the lowermost- 17 indicates the mouth of a pipe for the introduction of spray liquid, the upper end of which leads into the space immediately within the casing 12. 18 indicates the entrance to the tube 11 which, with tube 2, conducts air to the mixing chamber 3. A flexible tubular connection transmits liquid to be sprayed from its supply tank to the liquid entrance of the spray gun at 17, and a similar flexible tubular connection transmits compressed air from its source of supply to the entrance of the spray gun at 18. Pressures in the liquid and air systems at 17 and 13 are substantially equal, so that there is no tendency for one element to enter the ducts of. the other by returning through the mixing chamber 3. Instead both elements enter the mixing chamber with considerable velocity at a converging angle of less than 45 and proceed outward through the spray discharge orifice 1 with little reduction in driving force, thus a second or. compound atomization of the liquid and air mixture takes place when this strikes a the atmosphere, and the resulting very fine spray is carried to considerable distance beyond the nozzle. The foregoing describes the essential relation of the ducts for transmitting the liquid and air from their sources through the spray gun. 7 i
Referring to the whirl member 8, the passageway between the member 8 and the tube 2 is provided with laterally extending ports 5, as shown in FIGS. 1 and 2,.
and through which ports liquid to be sprayed is led to the slots 4which are formed on the exterior of the conical face 8 of the whirl body 8. These slots are formed diagonally on the conical surface 8 and are adapted to provide liquid to be atomized with a vortical motion as indicated in FIG. 3. The passageway between member 8 and tube 2 terminates. above the'lateral passages 5 and the upper end of member 8 has a center bore only large enough to permit the tube 2 to slide within it. Thus'this bore holds tube 2 concentric in the whirl member 3.
In FIG. 4, there is illustrated a modification of the device shown in FIG. 1. This modified form, as shown in FIG. 4, is intended for use in multiple; that is, more than one nozzle on a pipe or boom and directing sprayedliquid in atomized form downwardly to cover an'area of some width in spraying golf greens'and the like. 21 indicates the main portion of an'outer casing and 17 indi-- cates an intake pipe mounted on said casing 21, and which intake pipe is intended for the introduction of liquid to be sprayed. 18 indicates a tube forthe introduction of air. The lower end of the tube 13 terminates inwardly from the discharge orifice 1, thus providing a mixing chamber 3. V
In this modification, according to FIG. 4, the tube 18 extends through acapscrew 19 to which the tube 18 may be welded as shown, or it may be movably mounted in a stufling box, as in FIG. 1, thus permitting external spray adjustment 'by moving this tubelS toward or away from orifice 1.. The capscrew 19 is threaded into the casing 21 and between these parts a gasket 20 is provided. 22 is a cylindrical screen which encircles the tube 18 and is spaced away from the tube so that liquid to be sprayed entering through the pipe 17 may encircle the screen and be filtered thereby enrouteto the mixing chamber S. After passing through thescreen 22, the liquid may enter spiral passageways or ducts 23 and 24 which are easily formed by cutting; double, square female threads, or rifles in the center bore of whirl 8 through which tube 18 passes. These double threads, havingtwo separate helices, f form the opposite sides of two separate ducts designated.
23 and .24 respectively, while tube18 forms the fourth sideof both. These ducts have their discharge openings at the. upper side :of the mixing chamber '3. The spiral movement of the liquid to be atomized and sprayed provides a vortical discharge forthe liquid as it enters the mixing chamber and at that time air discharging from,
are evenly diffused throughout the carrying air stream.v
the opening 2 at the lower end of the tube 18 serves to provide atomizing force and also blows the liquid and air mixture "throughjthe outlet orificel.
FIG. 5 is a view of the whirl body 8 looking upwardly into the discharge ducts 23 and 24, the center opening of tube 18 being indicated at 2.
FIG. 6 is a side view of the whirl body 8.
FIG. 7 is a vertical cross sectional view somewhat enlarged taken centrally through the whirl body 8 showing the passageway 23 in solid lines. Only the ends of passageway 24 are shown since the rest of it is in the .half of the whirl body nearest the observer and hence does not appear in this sectional view.
FIG. 8 is a bottom view of the whirl block 8 of FIG. 4 somewhat enlarged, the arrows indicating the path of vertical movement of the liquid to be sprayed and It is desirable that the metal parts of the spray devices illustrated in the drawing be of rust proof material and such is not to be readily corrodible by the chemicals used in spraying.
While this invention is disclosed specifically with reference to the use of the atomizing and driving force of compressed air at approximately 30 lbs. p.s.i. for applying fine sprays to delicate articles and surfaces with this spray evenly diffused throughout a carrying air blast to avoid injury to such articles and surfaces, I do not wish to be limited to the details herein disclosed otherwise than as set forth in the following claims.
l. A spraying device comprising an outer tubular casing, an interior tube extending lengthwise of said outer casing for the passage of compressed air, said interior tube being tightly sealed at its discharge end to a smaller tube which limits the quantity and imparts high velocity to the discharge of said compressed air, a packing gland encircling said inner tube and secured to said outer casing at one end thereof, a nozzleat the end of said outer said outer casingand interior tube, and means within said nozzle having a fluid tight connection with respect'to said outer casing for delivering a medium to be sprayed to a point within said mixing chamber, said means having discharge slots on its outer surface, and next adjacent the inner surface of said nozzle, said slots extending diagonally and at minimum converging angle with respect to the longitudinal axis of said interior tube whereby a whirling movement of the medium to be sprayed is effected and said whirling medium is given equally high flow velocity and moved :in substantially the same. direction as said ,air discharging from said interior tube so that said air and said medium mix in said mixing chamber with little loss of velocity and issue from said discharge opening with great driving force and withsaid spray medium atomized into extremely fine droplets which 2. A device as set forth in claim 1, wherein themeans. for effecting a .whirlingmotionto liquid to be sprayed comprises a body having a central bore through which said interior tube passes and an outerwall with less than 45 taper adjacent oneend of said body and having a plurality ofslots in the tapered outer surface arranged diagonally with respect to said bore, and said body having an annular groove leading to saidslots and a communicating laterally extending port leading from said bore-to said groove thusproviding means for deliveringa medium to be sprayed from the space between said outer casing and said interior tube to. a point within said mixing chamber, said body having a seating surto control the passage of liquid tosaid mixing chamber 3. A spraying device comprising an outer tubular casing adapted to contain a medium to be sprayed, an interior tube extending lengthwise of said outer casing for the passage of low pressure compressed air, a packing gland encircling said interior tube and secured to said outer casing at one end thereof, a nozzle at the end of said outer casing distant from said packing gland, said nozzle having a discharge opening and a mixing chamber interiorly of said discharge opening, an intake pipe for admission of a medium to be sprayed leading to a space between said outer casing and said interior tube, and means within said outer casing for delivering a medium to be sprayed to a point within said mixing chamber, said means having a central bore therethrough through which said interior tube extends, said means having spirally extending grooves of double screw threads with not more than two pairs per inch located in the Wall of said means next adjacent the outer Wall of said interior tube thus forming ducts which deliver liquid into the mixing chamber with vortical motion but at no converging angle to the air flowing intoysaid' chamber from said interior tube so that both air and liquid blend smoothly in said mixing chamber and spray from the nozzle with little loss of initial velocity.
References Cited by the Examiner UNITED STATES PATENTS 1,514,135 11/24 Cravens 239-401 2,247,781 7/41 Leiman 239-405 2,254,123 8/41 Soaper 239-405 2,359,722 10/44 Zink 239-403 2,372,283 3/45 Kooistra 239-405 2,826,454 3/58 Coanda 239398 2,854,285 9/58 Barton 239'399 3,100,084 8/63 Biber 239399 3,131,869 5/64 Vega et al. 239-424 EVERETT W. KIRBY, Primary Examiner. LOUIS J. DEMBO Examiner.