Spray nozzle with recessed deflector surface

Abstract: A spray nozzle assembly (11) having a spray tip (20) formed with an elongated, cylindrical chamber (30) communicating with the liquid supply and being formed with a cross-slot (34) which intersects the chamber at a location intermediate the ends thereof for defining a discharge orifice (31), a deflection surface (32) on a downstream side of the discharge orifice (31) for directing liquid in a direction transverse to the axis of the chamber, and a pocket (38) extending downstream of the deflector surface. In one embodiment, the spray tip has a pre-orifice (42) substantially smaller in diameter than the chamber (30) adjacent an upstream end thereof, in another embodiment, the chamber (30 a ) is disposed with its axis at an angle to the vertical and the cross-slot (34 a ) extends upwardly in substantially vertical relation for defining a vertical deflection surface, and in still another embodiment the spray tip (20 d ) has a wear resistant metal insert (72).

Description: FIELD OF THE INVENTION The present invention relates generally to spray nozzles, and more particularly, to spray nozzle assemblies of the type which have a spray tip with a transversely oriented deflector flange formed with a distinct recess or pocket for the purpose of effecting a particular desired liquid distribution in the discharging spray. BACKGROUND OF THE INVENTION Spray nozzle assemblies are known, such as shown in U.S. Patent 4,899,937 assigned to the same assignee as the present invention, which include a deflector flange that enhances particle breakdown and directs the spray pattern in a transverse direction. The deflector flange of the nozzle shown in the aforesaid U.S. Patent is formed with a distinct recess or pocket in axial alignment with the liquid discharge orifice in the nozzle tip, which has been found to generate a spray pattern that has shallow bell-shaped liquid distribution curve with greatest quantities of liquid being directed in a central portion of the spray pattern and lesser quantities on opposite sides thereof so that overlapping spray patterns from a plurality of such nozzles mounted in laterally spaced relation to each other, such as on the boom on an agricultural sprayer, produce a substantially uniform distribution of liquid over the area being sprayed. In hydraulic spraying applications, namely applications in which the liquid flow stream is not subject to air-assisted pre-atomization, such nozzles have been found to be susceptible to excessive wear that can alter the spray characteristics and substantially increase the liquid flow. Although wear is reduced if the liquid is pre-atomized by pressurized air prior to direction through the nozzle spray tip, such air assisted spraying generates a fog-like discharge of relatively fine liquid particles. In agricultural applications, unless such discharging spray is directed in a substantially straight downward direction, the fine liquid particles are subject to undesirable drift. Heretofore, it often has not been possible to easily mount such spray nozzles for straight downwardly directed spraying, particularly on booms which are adapted for vertical spray nozzle mounting. Since the deflector flange of the nozzle is disposed transversely to the discharge orifice, such nozzles also have been susceptible to clogging by solid materials that might be included in the liquid being sprayed. We are aware of FR-A-1419895 which forms the pre-characterising portion of claim 1. In FR-A-1419895 the first and second chambers are coaxial. We are also aware of EP-A-0518666 which is available for novelty purposes only under Article 54(3) and (4) EPC in so far as the designated states of DE, FR, GB and IT are concerned. According to our invention in a spray nozzle assembly comprising a stem having a liquid passage through which a supply liquid is directed, a spray tip means for mounting said spray tip said stem for receiving supply liquid from said stem passage and for directing the liquid in a predetermined spray pattern, said spray tip being formed with a first chamber communicating with said stem passage through which liquid is directed in an linear direction parallel to the axis of said first chamber, said spray tip being formed with a second chamber through liquid which is directed in a linear direction parallel to the axis of said second chamber, said spray tip having a preorifice communicating between said first and second chambers sized substantially smaller in diameter than said second chamber, said spray tip having a cross slot which intersects said second chamber location intermediate opposite ends thereof for defining a discharge orifice, a deflection surface on a downstream side of said discharge orifice for directing liquid discharging from said orifice in a direction transverse to the axis of said second chamber, and a pocket extending downstream from said deflection surface, said second chamber is oriented with its axis at an angle to the axis of said first chamber. This has the advantage that liquid particles generated within the second chamber are directed through the discharge orifice and along the deflector surface where they are broken down further for ultimate direction in a foam-shaped spray pattern. The discharging spray generates a shallow or flat bell-shaped liquid distribution curve, with lessor quantities of liquid being generated on opposite sides of the spray pattern. This, in turn, enables the discharging sprays of adjacent nozzles to be directed for slight overlap with the resultive liquid distribution across the area sprayed being substantially uniform for optimum application of agricultural chemicals and the like. Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings, in which: BRIEF DESCRIPTION OF THE DRAWINGS FIGURE 1 is a partially diagrammatic depiction of the performance of a plurality of nozzles assemblies embodying the present invention mounted in laterally spaced relation to each other on a spray boom, with the liquid distribution curve of each nozzle assembly depicted below the respective nozzle assembly; FIG. 2 is an enlarged fragmentary section of one of the spray nozzle assemblies, as known from EP-A-0 518 666. FIG. 3 is an enlarged vertical section of the spray tip of the nozzle assembly shown in FIG. 3, taken in the plane of 3-3; FIG. 4 is a side elevational view, in partial section, of an embodiment of the spray nozzle assembly according to the present invention; FIG. 5 is an right-side elevational view of the spray tip of the nozzle assembly shown in FIG. 4; FIG. 6 is a fragmentary vertical section of another alternative embodiment of the spray nozzle assembly; and FIG. 7 is a right-side elevational view of the spray tip of the nozzle assembly shown in FIG. 6. While the invention is susceptible of various modifications in alternative constructions, certain illustrated embodiments thereof have been shown in the drawings and will be described below in detail. It should be understood, however, that there is no intention to limit the invention to the specific forms disclosed, but on the contrary, the intention is to cover all modifications, alternative constructions and equivalence falling within the scope of the invention as defined in the claims. DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now more particularly to FIGS. 1-3 of the drawings, there is shown a spray boom 10, such as the boom of an agricultural sprayer, having mounted thereon a plurality of spray nozzle assemblies 11 in accordance with the invention. The boom 10 in this instance is a tubular member through which the supply liquid is directed. Each spray nozzle assembly 11 includes a stem 12 having a nipple 14 extending into the boom 10 through an aperture in one side thereof. Pressurized liquid supplied to the boom 10 enters the stem 12 through the nipple 14 and passes through a central fluid passageway 15 in the stem 12 for direction through and discharge from a spray tip 20 mounted at the outer end thereof. The stem 12 is secured to the boom 10 by appropriate means, such as a clamp 21. For removably securing the spray tip 20 to the stem 12, a retention cap 22 is provided, which may be of the type disclosed in Butterfield et al. U.S. Patent 4,527,745. The spray tip 20 has an outwardly extending flange 24 at its upstream end, seated in the cap 22 and a body portion 25 extending outwardly of the cap 22 through a central aperture therein. The retention cap 22 in turn is telescoped over the outer end of the stem 12. For locking the cap 22 and spray tip 20 in predetermined position on the stem 12, the stem 12 and cap 22 may be formed with cooperative locking lugs and slots as is known in the art. A resilient annular gasket 26 is interposed between the end of the spray tip mounting flange 24 and the end of the stem 12, and a strainer 28 is secured within the flow passageway 15 of the stem 12 with a mounting flange 29 thereof interposed between the resilient gasket 26 and a seat formed in the end of the stem 12. Liquid directed through the stem 12 passes through the strainer 28 prior to its direction through the spray tip 20. The spray tip 20 is formed with an elongated chamber 30 that extends into the body 25 from an upstream end thereof for communication with the liquid passageway 15 in the stem 12. For defining a discharge orifice 31 and a deflection surface or face 32 for directing liquid in a downward direction transverse to the longitudinal axis of the stem 12 and spray tip 20, the spray tip 20 is formed with a cross slot 34 extending upwardly from and underside thereof. The cross slot 34 in this case defines a generally vertically directed upstream face 35 with the downstream deflection face 32 being oriented at an angle of about 15 degrees with respect to the vertical. The apex between the cross slot faces 32, 35 is connected by a round 36 preferably extending to the longitudinal axis of the spray tip chamber 30, which has been found to define a spray pattern with a relatively wide angle  between about 120 and 130 degrees (FIG. 1) that is particularly desirable for agricultural spraying. Extending the cross slot 34 upwardly beyond the longitudinal axis of the chamber 30 has been effective for increasing the angle  of the discharging spray pattern up to and approaching 180 degrees. For enhancing liquid breakdown and atomization and for directing a discharging spray pattern with a shallow bell-shaped liquid distribution curve, the cross slot 34 intersects the chamber 30 intermediate the ends thereof for defining a significant recess or pocket 38 downstream of the discharge orifice 31 and deflector surface 32. The recess or pocket 38 extends beyond the deflector surface 32 a distance of at least twice, and preferably about 3 times the diameter of the chamber 30. While spray nozzles with recessed deflector flanges, such as shown in U.S. Patent 4,899,937, have been found effective for generating sprays with bell-shaped liquid distribution curves, as previously indicated, when used in hydraulic, non-air-assisted spraying applications, such tips have been found to experience significant wear about the discharge orifice and deflector surface. As a result, use of such nozzles have been largely limited to air assisted spray applications in which a pre-atomized liquid flow stream is directed through the spray tip. The nozzle spray tip defines a pre-orifice upstream of the discharge orifice which is sized substantially smaller than the nozzle tip chamber such that the chamber and the deflector surface recess form an expansion chamber that facilitates breakdown and direction of the liquid particles with significantly reduced wear, while not substantially affecting the bell-shaped character of the liquid distribution of the discharging spray. To this end, in the illustrated embodiment, the spray tip 20 includes a pre-orifice member 40 that is press fit or otherwise secured in the upstream end of the spray tip 20. The pre-orifice member 40 is formed with an inwardly tapered entrance passageway or throat 41 for receiving supply liquid from the flow passageway 15 of the stem 12 and which communicates with a cylindrical pre-orifice 42 having a diameter preferably on the order of about 1/2 the diameter of the spray tip chamber 30 for throttling and accelerating liquid into the expansion chamber defined by the spray tip chamber 30 and deflector surface recess 38. The pre-orifice member 40 in this case has an outwardly extending, annular flange 44 at its upstream end received in a counterbore formed in the spray tip 20 for locating the upstream face of the pre-orifice member 40 flush with the upstream face of the nozzle tip 20. The discharge orifice 31 preferably has an area greater than the area of the pre-orifice 42 for insuring the free passage of the liquid entering the chamber 30. In operation, supply liquid from the boom 10 is directed to the spray tip 20 via the stem passageway 15. Liquid entering the spray tip 20 is accelerated as is passes through the pre-orifice 42 into the expansion chamber defined by the chamber 30 and deflector surface recess 38, where the liquid is broken down and mixed with significant turbulence. Liquid particles generated within the chamber 30 are directed through the discharge orifice 31 and along the deflector surface 32 where they are broken down further for ultimate direction in a fan-shaped spray pattern having a relatively wide angle  of between about 120 - 130 degrees, as illustrated in FIG. 1. As further depicted in FIG. 1, the discharging spray generates a shallow or flat bell-shaped liquid distribution curve 45, with lesser quantities of liquid being generated at opposite sides of the spray pattern, thereby enabling the discharging sprays of adjacent nozzles to be directed for slight overlap with the resulting liquid distribution across the area sprayed being substantially uniform for optimum application of agricultural chemicals and the like. The pre-orifice member 40 has been found to significantly minimize wear to the discharge orifice 31 and deflector surface 32 of the spray tip 30, and the downwardly directed discharge orifice 31 of the spray tip enables the nozzle assembly to be used for agricultural applications in both for hydraulic and air-assisted spraying modes. Referring now to FIGS. 4-5, there is shown a further alternative spray nozzle assembly wherein items similar to those described above have been given similar reference numerals with the distinguishing suffix "d" added. The spray nozzle assembly 11 d in this case includes a spray tip 20 d having a body 65, preferably molded of plastic, formed with an outwardly extending mounting flange 24 d at its upstream end for releasable securement to a stem 12 d by a retention cap 22 d . The spray tip body 65 has an upper end formed with a first cylindrical chamber 66 communicating at an upstream end with a stem passageway 15 d through a tapered throat 68. The first cylindrical chamber 66 has a vertical axis coincident with the axis of the stem passageway 15 d and a bottom or end wall 69 formed with an eccentrically located outlet passage 70 substantially smaller than the diameter of the chamber 66. In accordance with a further feature of the invention, the spray tip 20 d has a metallic tip insert 72 which is horizontally supported in the lower end of the body 65 and formed with an elongated cylindrical expansion chamber 30 d having a small diameter preorifice 42 d in a side wall thereof adjacent an upstream end communicating with the first chamber outlet passage 70. The preorifice 42 d in this case is smaller than the first chamber outlet passage 70 such that the discharge passage 70 defines an entry passage to the preorifice 42 d . The expansion chamber 30 d has a cylindrical configuration with an axis at an angle, in this case perpendicular, to the axis of the first chamber 66 and the preorifice 42 d is formed in a top side of the insert 72 adjacent the upstream end. For supporting the tip insert 72, the spray tip body 65 is formed with a cylindrical cavity 74 opening to one side thereof and the spray tip insert 72 is mounted within the cavity 74 with a downstream end extending out the open side. The insert 72 preferably is press fit within the cavity 74. For defining a discharge orifice 31 d for the nozzle assembly and a deflection surface 32 d for directing a discharging liquid spray in a substantially downward direction, the spray tip insert 72 is formed with a substantially vertically oriented cross-slot 34 d which extends through an exposed underside of the insert 72 adjacent an end of the chamber 30 d opposite the preorifice 42 d . The cross-slot 34 d has a "V" configuration with an upstream face 35 d thereof vertically oriented and a downstream face 32 d disposed at an angle of about 15 degrees to the vertical. The upper end or apex of the cross-slot 34 d is in the form of a round that extends about to the horizontal axis of the spray tip insert expansion chamber 30 d . For enhancing liquid breakdown and generation of a shallow liquid distribution curve, the cross-slot 34 d is located upstream of the end of the chamber 30 d so as to define a distinct pocket or recess 38 d extending downstream of the deflector surface 32 d . The discharge orifice 31 d preferably has an area equal to or greater than the area of the preorifice 42 d for ensuring the free passage of the liquid entering the chamber 30 d . It will be appreciated by one skilled in the art that while the spray tip 20 d may be mounted on a vertically oriented stem 12 d for downwardly directed spraying, the tip 20 d nevertheless has a relatively simple and compact design. Moreover, while the plastic spray tip body 65 lends itself to economical manufacture, the metallic spray tip insert 72 permits long term wear resistance usage of the nozzle assembly 11 d . Referring now to FIGS. 6-7, there is shown a spray nozzle assembly 11e, substantially similar to that shown in FIGS. 4-5, but formed entirely of plastic. The spray nozzle assembly 11 e includes a spray tip 20 e having a body 65 e formed with a first vertically oriented, cylindrical chamber 66 e having a tapered entry throat 68 e at an upstream end. The chamber 66 e has a bottom or end wall 69 d in this case directly formed with a preorifice 42 e disposed in off centered relation to the axis of the chamber 66 e . The preorifice 42 e has a tapered upstream entry throat 41 e . In accordance with a feature of this embodiment of the invention, the nozzle body 65 e defines a second cylindrical expansion chamber 30 e disposed below the first chamber 66 e with the preorifice 42 e communicating with a top side of the expansion chamber 30 e adjacent an upstream end thereof. The nozzle body 65 e further is formed with a discharge orifice 31 e defined by a cross-slot 34 e extending upwardly from an underside of the nozzle body 65 a adjacent an end of the horizontal chamber 30 e opposite that of the preorifice 42 e . The discharge orifice 31 e again has an upstream face 35 e that is vertically oriented and a downstream face 32 e disposed at a small angle to the vertical, such as 15 degrees. The cross-slot 34 e is disposed upstream of the end of the expansion chamber 30 e so as to define a distinct pocket or recess 38 e downstream of the deflector surface 32 e . To facilitate plastic injection molding of the nozzle body 65, it will be appreciated by one skilled in the art that the plastic body 65 may be formed with the second chamber 30 e open at one end, such as at the upstream end, which can thereafter be closed by a plastic plug 81, which may be secured by ultrasonic welding. From the foregoing it can be seen that the spray nozzle assembly of the present invention is particularly adaptable for spraying agricultural chemicals with a substantially uniform liquid distribution over the area being sprayed. The nozzle assembly may be used in both purely hydraulic and air-assisted spray applications, and in the latter case, is easily adaptable for directing discharging sprays in a substantially straight downward direction. The nozzle is less susceptible to undesirable wear and clogging.

Claims: A spray nozzle assembly comprising, a stem (12 d ) having a liquid passage through which a supply liquid is directed, a spray tip (20 d ), means (22 d ) for mounting said spray tip (20 d ) on on said stem (12 d ) for receiving supply liquid from said stem passage and for directing the liquid in a predetermined spray pattern, said spray tip (20 d ) being formed with a first chamber (66) communicating with said stem passage through which liquid is directed in an linear direction parallel to the axis of said first chamber (66), said spray tip (20 d ) being formed with a second chamber (30 d ) through liquid which is directed in a linear direction parallel to the axis of said second chamber (30 d ), said spray tip (20 d ) having a preorifice (42 d ) communicating between said first and second chambers (66, 30 d ) sized substantially smaller in diameter than said second chamber (30 d ), said spray tip (20 d ) having a cross slot (35 d ) which intersects said second chamber (30 d ) at a location intermediate opposite ends thereof for defining a discharge orifice (31 d ) a deflection surface (32 d ) on a downstream side of said discharge orifice (31 d ) for directing liquid discharging from said orifice in a direction transverse to the axis of said second chamber (30 d ) and a pocket (38 d ) extending downstream from said deflection surface (32 d ) characterized by said second chamber (30 d ) being oriented with its axis at an angle to the axis of said first chamber (66). The spray nozzle assembly of claim 1 in which the axis of said first chamber (66) is vertically disposed. The spray nozzle assembly of claim 1 in which the axis of said second chamber (30 d ) is at a right angle to the axis of said first chamber (66). The spray nozzle assembly of claim 1 in which said first and second chambers (66, 30 d ) are cylindrical. The spray nozzle assembly of claim 1 in which said preorifice (42 d ) communicates with one end of said second chamber (30 d ) and said cross slot (35 d ) intersects said second chamber (30 d ) at a location adjacent an end thereof opposite said preorifice (42 d ). The spray nozzle assembly of claim 4 in which said second chamber (30 d ) is cylindrical with a diameter at least twice the diameter of said preorifice (42 d ). The spray nozzle assembly of claim 1 in which said stem (12 d ) is vertically oriented, said second chamber (30 d ) being oriented with its axis at an angle to the vertical, and said cross-slot (35 d ) extending substantially vertically upwardly into and underside of said second chamber (30 d ). The spray nozzle assembly of claim 1 in which said spray tip (20 d ) has a plastic body (65) in which said first and second chambers (66, 30 d ) are formed. The spray nozzle assembly of claim 1 in which said spray tip (20 d ) includes a plastic body (65) formed with said first chamber (66), said plastic body (65) further being formed with a cavity (74) communicating with said first chamber (66) through an aperture (70) in said body (65) adjacent an end of said cavity (74), a spray tip insert (72) mounted within said cavity (74) and defining said second chamber (30 d ), said preorifice (42 d ) being formed in said spray tip insert (72) and communicating with said first chamber (66) through said aperture (70), and said discharge orifice (31 d ) being formed in said spray tip insert (72) at a location outside said cavity. The spray nozzle assembly of claim 9 in which second chamber (30 d ) has an elongated cylindrical configuration with a horizontal axis, said preorifice (42 d ) extends through a top side of said second chamber (30 d ), and said discharge orifice (35 d ) communicates with said second chamber (30 d ) from an underside thereof. The spray nozzle assembly of claim 9 in which said spray tip insert (72) is formed of metal. The spray nozzle assembly of claim 7 in which said spray tip (20 d ) has a body (65 e ) with a plug (81) affixed thereto enclosing one end of said second chamber (30 d ). The spray nozzle assembly of claim 12 in which said plug (81) encloses an upstream end of said second chamber (30 d ). The spray nozzle assembly of claim 13 in which said preorifice (42 d ) is formed in said body (65 e ).

Inventors: HARUCH JAMES, HARUCH, JAMES
Applicants: SPRAYING SYSTEMS CO, SPRAYING SYSTEMS CO.
Application year: 1993
Main classification: B05B1
IPC codes: B05B1