Spinner Nozzle For Air Blast Orchard Sprayer

Abstract

An atomizing nozzle of the type used for discharging liquid agricultural chemicals into the air blast of an orchard sprayer, and including a discharge bell, or spinner cone, having external air vanes to spin the cone and centrifugally disperse the spray. The spray solution is directed into the cone by a fixed conduit and spray nozzle which are externally located with respect to the cone and its rotary mounting structure in order to eliminate internal flow passages from which the incoming spray solution might escape and cause corrosion or blockage to impair the operation of the nozzle.

Parent Case Text

CROSS-REFERENCE TO RELATED APPLICATION

This application is a division of application Serial No. 27,017 filed Apr. 9, 1970, now U.S. Pat. No. 3,666,177.

Description

BACKGROUND OF THE INVENTION

The present invention concerns spray nozzles of the spinning type which are used in orchard sprayers that generate an air blast in which the spray is entrained and carried to the foliage to be treated. Spin-type nozzles employ external vanes on a centrifugal spray distributor that is spun by the air blast impinging upon the vanes.

DESCRIPTION OF THE PRIOR ART

Spray nozzles of the vane-driven spinning type are known in the prior art, one example of which is shown in U.S. Pat. No. 3,552,652, and generally include a discharge bell or spinner cone which is rotatable on a fixed support having an axial flow passage for supplying spray solution to the interior discharge surface of the bell. Because of the prior art conceptions of spinner nozzle construction and operation, the usual spinner nozzle requires more or less elaborate seals, close tolerances, and other costly structural details for the purpose of preventing clogging of the liquid when it is delivered to the discharge bell. Most spray solutions are highly corrosive and are often contaminated with scale or other undesirable debris which lead to clogging or flow restriction and impair or prevent rotation of the discharge bell. Since the application of pesticides and the like is usually a closely controlled operation to provide effective coverage with the proper amount of spray concentrate, it is evident that the result of malfunctioning or inoperative nozzles is of serious consequence to the user. Another problem is that it is usually difficult to alter the output of most spinning nozzles because the flow rate is fixed by the restrictions in the internal passages.

Another disadvantage of prior art spinning nozzles which include spinning cones fed through internal passages in the nozzle structure is that the pressure drop in the passages can create a partial vacuum tending to draw the spray solution into the bearings and other areas which must be isolated for proper operation of the nozzle. An attempted prior art solution is the provision of radial relief passages drilled into the discharge bell near the apex thereof to break or alleviate the vacuum, but this structure has not completely solved the problem.

SUMMARY OF THE INVENTION

The present invention completely eliminates internal flow passages in the relatively rotatable portions of the nozzle to eliminate the aforementioned disadvantages of the prior art nozzles and provide a trouble free nozzle particularly well adapted to an air blast type of orchard sprayer. The nozzle according to the invention comprises a hollow spinner cone provided at its apex with an external body carrying spinner blades, said spinner cone being rotatably carried by a fixed shaft projecting from a support, and a nozzle supply tube located outside of said spinner body, said tube being bent near its free extremity, the latter penetrating into said cone and being located near the apex thereof. Since the spinner cone is externally fed through the supply tube, spray solution cannot easily reach or contaminate the bearings for the spinner cone.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 schematically illustrates the configuration of a sprayer embodying the invention;

FIG. 2 is an enlarged view, partially in axial section,of a nozzle as indicated by F.sub.2 in FIG. 1;

FIG. 3 is a view according to line III--III of FIG. 2;

FIG. 4 is a cross-section according to line IV--IV in FIG. 2.

As shown in FIG. 1, a sprayer embodying the invention comprises an engine 1 driving a fan 2 and a variable capacity hydrualic pump 3, a clutch 4 in the fan drive, allowing to disconnect the fan for road travel or other operations. The following is a brief description of one operating environment for the spinner nozzle of the present invention, as disclosed in the previously identified parent application, Ser. No. 27,017, now U.S. Patent No. 3,666,177.

Pump 3 feeds a hydraulic motor 5 through conduits 6 and 7, the latter comprising control means 8 to adjust the capacity of pump 3.

The output shaft 9 of motor 5 has a wheel 10 keyed thereto and is connected to the driven or input shaft 11 of an axle assembly 12. Said assembly comprises a differential 13 and drive wheels 14 and 15 for the sprayer. If necessary, shafts 9 and 11 may be coupled via a gear reduction 16.

Wheel 10 drives a wheel 17, through a chain or belt 18, said wheel 17 being keyed to the shaft 19 of a variable capacity pump 20. Preferably the latter will be of the wobble-type, with adjustable wobble-plate. This pump 20 has an inlet conduit 21 connected to a liquid tank (not shown) and an outlet pipe 22 feeding a group of nozzles 23 located in the trajectory of the air blast generated by fan 2. A clutch 24 may be provided to disconnect pump 20 during road travel.

This configuration allows to preset the engine speed to drive the fan at a constant speed, which is essential for good spraying.

Notwithstanding the constant speed of engine 1, the ground speed of the sprayer may be modified by acting on pump 3, through control means 8. The liquid pump 20, will, in any case, be driven proportionally to the ground speed of the sprayer.

As shown in FIGS. 2-4, the present invention is concerned with nozzles 23. Each of such nozzles is a spinning nozzle which comprises a hollow spinner cone 25 having an external, cylindrical body 26 at its apex. An axial, shouldered bore 27 traverses the cone-body unit. Said body 26 is provided at its periphery with spinner blades 28. The assembly thusfar described is rotatably mounted on a shaft 29, extending through the lower part of bore 27 as seen in FIG. 2 and therein supported by a bushing or bearing 30. At both extremities of the latter, retaining and seal rings 31 and 32 are mounted around shaft 29. The air blast from the fan 2 impinges upon the blades and causes the body 26 to rapidly rotate.

The threaded lower extremity of shaft 29 is screwed in a fixed support 33 having a flanged, cup shaped upper part 34 facing said body 26. The upper part of bore 27 is threaded and receives a water-tight plug 35. A nozzle supply tube 36 is connected to a liquid passage 37 provided within support 33, and extends externally of the nozzle assembly. The free end portion of said tube is bent so that it partly penetrates into the cone 25. Said free end is either provided with a calibrated orifice for the passage of liquid or, as shown, has a threaded end to which a "nozzle" 38 is screwed. This construction allows to easily and speedily adapt the nozzles in special cases.

As some of the spinning nozzles 23 are often located one above the other, it might happen that liquid could drip from an upper to a lower nozzle into the space between the body 26 and the cup-shaped part 34 of support 33, and somehow reach the bushing 30 notwithstanding seal 32. To prevent this, the free circular face 39 of body 26 is provided with a series of spiral grooves 40, extending from the centre to the peripheral edge of said face. In operation, any liquid that might possibly get by the flanged ends of cup-shaped part 34 would be spun out by said grooves, during the rotation of body 26. Vent holes 41 can also be provided in said part 34.

The part of feed tube 36 extending in front of the spinner cone 25 can be aerodynamically profiled, as indicated at 42 in FIGS. 2 and 4.

The upper face 43 of the liquid-tight plug 35 can be either flat or profiled to assist in breaking up the liquid droplets to the desired size. Plug 35 is removed only for disassembly of the shaft bearing, respectively 29 and 30. It will be evident that the structural organization of the spinning nozzle 23 assures that the spray solution cannot contaminate the bearing surfaces or any other relatively moving parts to impair the free rotation of the spinner cone 25 and that the flow characteristics of the nozzle will remain constant over a long period of use.

Of course, numerous modifications or additions may be brought --as specific circumstances dictate-- to the embodiment described hereabove by way of example only, without departing from the scope of the invention.

Claims

What I claim is:

1. For use in an air blast orchard sprayer, a nozzle comprising a hollow nozzle cone extended at its apex by an outer cylindrical spinner body carrying spinner blades, a fixed shaft projecting from the center of a cup shaped part of a fixed support, for rotatably supporting said nozzle, said spinner body having a circular end face provided with spiral grooves extending from the center to the periphery thereof, vent holes being provided into said cup shaped part, and a nozzle supply tube external of said spinner body positioned so as to direct fluid into the apex of said nozzle cone.

2. A spinning nozzle for an air blast sprayer comprising a support having a threaded shank for affixing one end of the support to a liquid supply manifold, said shank including an internal passage communicating with the manifold, an axle shaft extending axially from the other end of said support, a spinner cone having a body portion mounted on said axle shaft for free rotation, said spinner cone having an outwardly open end directed away from said axle shaft and outwardly extending spinner blades on said body portion for rotating said spinner cone in the air blast, said body portion having an end face confronting said support, said face being provided with slinger grooves radiating from said axle shaft to disperse liquid from said face by centrifugal force, and an exterior tube connected to said passage and terminating within the open end of said spinner cone, said tube having a streamlined section to minimize turbulence of the air blast and providing the only supply of liquid for centrifugal dispersion by said spinner cone into the air blast.

3. For use in an air blast orchard sprayer, a spinning nozzle assembly comprising a hollow open-ended spinner cone for distributing spray liquid outwardly thereof from its open end and having externally thereof at its closed apex end generally radially extending air-driven blades, a support disposed adjacent said cone apex end, a fixed shaft projecting from said support toward and rotatably journaled within said cone at its closed apex thereby to permit free rotation of said cone on said support when an air blast impinges against said blades, and a single supply passage for spray liquid comprising a tube carried by said support extending externally therefrom outside of said spinner cone and terminating in a reversely bent portion defining a discharge orifice disposed within the open end of said cone, whereby said spray liquid is discharged from said tube solely within said air-driven spinning cone for distribution outwardly therefrom and away from the rotatable shaft mounting therefor.

4. The spinning nozzle assembly of claim 3 further including a screw-threaded portion of said tube which defines said discharge orifice.