Patent Grant
10583448
© 2016 On Target Spray Systems, Inc. A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever. 37 CFR § 1.71(d).
Electrostatic spray modules have been used for applying agricultural liquids such as a pesticide to crops where, externally to the spray module the number of connections is reduced to three, one for the liquid pesticide, one for compressed air and one for a low voltage signal. Internally to the spray module, a low voltage is converted to a high voltage signal, which is, along with the pesticide and the compressed air delivered to one or more electrostatic spray nozzles using only two electrically conductive pipes, a gas delivery pipe and a liquid delivery pipe. The nozzles fit into the gas delivery pipe and draw the compressed air through gas channel openings in the side of the nozzles.
In prior art, the gas delivery pipe doubles as the means to deliver the high voltage signal to the nozzles. Each nozzle has a liquid feed from the liquid delivery pipe, which carries ground voltage, maintaining the liquid at ground voltage. The grounded liquid merges with the compressed air in the nozzles to form an atomized liquid. The atomized liquid then passes through an electrode, which is electrically charged by the high voltage signal to form an electrostatic spray. The electrical charge in the spray leads to better dispersal of the spray due to the droplets in the spray repelling from each other, and further improves the adherence of the spray to crops which attract the charged droplets. Examples of the prior art are shown in U.S. Pat. Nos. 6,003,794 and 6,138,922 and 6,227,466 each of which is incorporated herein by this reference.
The prior systems suffer various problems and limitations. First, there is high-voltage current leakage that often occurs where nozzles extend through the shell or casing that encloses the sprayer. Further, the orifice sizes of the nozzles are difficult to change for different applications without tools. Also, the high-voltage power supply may not provide an optimal high-voltage level for some applications. Further, there are challenges and lost time spent in repairing and reconfiguring sprayer systems for different applications. Various improvements to electrostatic spraying equipment and control are disclosed in the description that follows.
The following is a summary of the invention in order to provide a basic understanding of some aspects of the invention. This summary is not intended to identify key/critical elements of the invention or to delineate the scope of the invention. Its sole purpose is to present some concepts of the invention in a simplified form as a prelude to the more detailed description that is presented later.
In an example, an electrostatic spray module may comprise the following elements:
a base unit formed of a sturdy, rigid, liquid impermeable, electrically insulative material;
a cover formed of a sturdy, rigid, liquid impermeable, electrically insulative material and sized for covering the base unit;
the base unit and the cover configured for mating engagement together so as to form a liquid impermeable, electrically insulative, protective enclosure when the module is in a closed state;
a quick access latch coupled to the base unit and to the cover so as to enable opening and conversely closing the protective enclosure to the closed state without tools;
the base unit including a plurality of spray nozzle assemblies mounted therein, each spray nozzle assembly including a corresponding nozzle body having a collar and a nozzle insert mounted in the nozzle body, each nozzle insert having an aperture of selected size for spraying material from the spray module; and
for each of the spray nozzle assemblies, a corresponding seal formed of a pliable, water impermeable, electrically insulative material, the seal extending circumferentially around the nozzle insert, interposed between the nozzle body collar and an interior surface region of the cover surrounding and defining an aperture integrally formed in the cover when the protective enclosure is in the closed state;
the seal including a central aperture and arranged so that the seal central aperture is aligned over the nozzle insert aperture so as to permit sprayed liquid to exit the nozzle insert and pass through the seal central aperture unimpeded during operation of the spray module.
Additional aspects and advantages of this invention will be apparent from the following detailed description of preferred embodiments, which proceeds with reference to the accompanying drawings.
The sprayer modules 104, 106 and 108 are shown as each having three nozzle assemblies, but this number is not critical. Each module may have more or less than three nozzle assemblies. Each nozzle assembly is arranged to controllably delivery, or spray, a liquid as indicated by dashed lines 110 during operation. In one embodiment, the three sprayer modules are substantially identical; therefore we will describe only one module in detail. Other configurations will be informed by the following description.
The base may include one or more integrally formed, rigid “towers” 263, 265 arranged to support a gas delivery manifold 242. The towers or similar structure may be affixed to the base if not integrally formed as part of it. Both the base and the cover may be formed, for example, by injection molding, 3D printing, or other processes. The manifold 242 supplies compressed gas to one or more nozzle assemblies in the sprayer module as further described later. The rigid towers 263, 265 are sized and shaped to hold the manifold 242 in a predetermined position inside of the module when the cover is attached; namely, the towers and manifold position the nozzle assemblies in alignment with corresponding apertures 204, 206, 208 in the cover 200 for delivery of a liquid (spraying) outside of the module while it remains closed; i.e., with the cover attached to the base. The manifold and other components preferably snap, clip, bolt or plug in to the base so as to reduce assembly and maintenance time and reduce the need for tools.
A compressed gas supply tube 120 may be used to supply compressed gas to modules 200 mounted on a boom 102. The supply tube 120 may be coupled to the boom. The supply tube may run within or alongside the boom, coupled to it for support at least intermittently.
Next, we describe an embodiment of a liquid supply system. Again referring to
Preferably, the valve assembly 330 is removably mounted to the base. In more detail, the base may include mounting features, for example, molded into the enclosure. In general, it is preferred that components such as the valve, power supply, etc. may snap, clip, bolt or otherwise plug into corresponding mounting features. Latches, tool less bolts, and the like may be used to avoid or reduce the need for tools, both during initial assembly and for maintenance and repair or replacement of individual components.
In an embodiment, the valve assembly may include an electro-mechanical device to enable remote control. In preferred embodiments, the valve assembly 330 may comprise a “zip valve” for example, a 12 volt on/off electric two-way ball valve. Such valves are commercially available, for example, from KZ Valve or its distributor. Electric actuated valves may be more durable that solenoid valves, and provide a fast cycle time. They may be run separately or “daisy chained” in series. This arrangement enables selectively turning on/off multiple spray modules with a single control.
The valve thus may be controllable by an electronic signal provided by a control cable 332 coupled to a remote or central controller. In this way, the liquid may be selectively provided (or not) to each sprayer module. A clogged or damaged module, for example, may have the liquid source valve remotely turned off, while other modules on the same boom (or not) may continue to operate normally. See the description of control panel 800 below.
The valve assembly 330 provides the liquid, when the valve is open, through an internal liquid feed line 316 to a rigid liquid delivery pipe 326 mounted in the base 240. The liquid feed line may pass through an aperture 252 formed in the base to accommodate it. Preferably, the liquid feed line 316 is coupled to the delivery pipe 326 by a removable, for example, threaded, fitting. A similar fitting may be provided on the delivery pipe 326 for each of the nozzle assemblies 300 mounted in the gas manifold 242 so that each nozzle body receives the liquid for spraying. In an embodiment, the individual liquid supply lines 328 that extend from the liquid delivery pipe 326 to the corresponding nozzle may be disconnected. That is, for one or more selected nozzles, for example, a clogged nozzle, the corresponding supply line can be disconnected from the delivery pipe 326 and the hole in 326 temporarily covered with a cap or plug to prevent liquid leakage, and then spraying operations can resume using the nozzles that are still connected. The liquid delivery pipe preferably is removably installed in the base to facilitate initial construction, as well as removal for maintenance or replacement.
Next, we describe one embodiment of an electrical supply system for the sprayer module. Again referring to
The power supply 410 may convert the low-voltage input signal to a high-voltage output signal, say 1000 VDC. The high voltage preferably is selectable in a range of, for example, approximately 300 volts to 2500 volts. In some embodiments, the power supply may measure output current, and adjust the output voltage accordingly. In an embodiment, an LED light may be mounted in the module base or lid to indicate when the power supply is working properly. A warning light may be provided to indicate improper or out-of-spec operation. A warning light may be provided on a control panel, see
The power supply 410, as noted, preferably is a variable power supply. It may have a selectable output voltage. The cable 260 may include one or more additional wires to carry one or more control signals for selecting the output voltage. The control signals may implement one-way or two-way communications. For example, various 2-wire serial communication interfaces are known for digital data communications. In other embodiments, a simple analog interface may carry a single control signal—one to select output voltage in the case where power supply 410 is a variable voltage supply. To illustrate, the single control signal may have a range of say 0-15 VDC. This control signal level may cause the power supply to output a corresponding higher output voltage, for example, in a range of 200-VDC. The output high voltage may be proportional to the control signal level. Or, other transfer functions may be used.
In an embodiment, the output voltage level may be quantized; for example, it may have only four output voltages. The mapping from control signal level may be along the lines of those shown in the following table. The figures in the Table are merely illustrative and not intended to be limiting.
The high-voltage output signal from the power supply 410 is connected by a conductor 412 to the gas delivery manifold 242. The conductor may comprise a wire and lug, for example, or a soldered connection. In this way, the high-voltage output signal is supplied to the conductive gas delivery manifold, so that, in turn, the high voltage is supplied to each of the nozzle assemblies installed in the manifold because the nozzles are electrically conductive. The nozzle bodies should be removably installed in the manifold, for example, by threaded engagement, or a push-and-turn locking connection. The connection between the nozzle and the manifold should be substantially air-tight to maintain the air pressure applied inside the manifold by the compressed gas supply.
Each nozzle assembly may have a removable tip or insert 282. The insert 282 may be removable, for example, by threaded engagement with the nozzle body. Selection of different nozzle inserts may vary, for example, from full cone tips for cotton or tobacco-plant sucker control to flood jet spray tips for broadcast spraying. Inserts may be formed of stainless steel, brass or other conductive materials. The inserts may be color coded for easy identification. To change inserts in the shop or the field, a user simply pops open the cover 200, exposing the nozzles, whereupon the nozzle inserts can be removed and substitute inserts installed. Preferably, the inserts 282 may be removable and installable without tools, for example, by threaded interconnection, and knurled or flat surfaces to improve manual grip on the insert.
The various connectors shown in
The nozzle and seal are configured so that when installed, and the module is in the closed state, the nozzle seal forms a water impermeable seal between the cover and the spray nozzle insert, as best seen in
Another switch 836 labeled “E” may be used to control the electrostatic power supplies in the spray modules of the corresponding spray system. This switch 836 preferably is coupled to all of the power supplies, to switch all of them ON or OFF with one action. An alarm signal, for example, audible and/or a light 838 may be used to alert an operator to a predetermined alarm condition. Alarm conditions may be responsive to return signals from the individual power supplies. For example, if the E switch 836 is off, an alarm may remind the operator to turn on the switch to enable electrostatic spraying. In another example, an alarm may indicate a low voltage condition (i.e., voltage below a predetermined threshold level) reported from one or more power supplies. An empty tank (say chemical or water) in the sprayer may trigger an alarm. Other alarm conditions may include, for example, over-voltage, low supply of spray liquid, low air pressure, etc.
Another switch 840 may be labeled “R” for rinse. This switch 840 may be used to switch the liquid source from a chemical tank to a water tank, to rinse out the sprayer system, without an operator leaving their position. This feature can be used at the end of a spraying row, or before leaving the cab for safety. Rinse can be used while the operator is returning the unit to refill spray chemicals.
Further with regard to control panel 800, it may include a series of switches 860 (labeled “VALVES”), to individually enable each one of a set of valves of the spray system. For example, one or more selected valves (say number 2 and number 6 for a desired spacing) can be selected for all of the active spray modules with the corresponding switch in bank 860. In another embodiment, a single switch 860 may be coupled to a set of modules mounted to a common boom. In some embodiments, a valve may correspond to valve assembly 330 in
Control panel 800 may also include means for high voltage adjustment by an operator. In one example, an analog switch such as a potentiometer may be varied by a knob 850. The control panel may provide a scale or indicia of a selected voltage, shown here as a range from 300 VDC to 2500 VDC. This range is adequate for most applications of a spray system. The high voltage setting on the control panel is used to control the individual high voltage power supplies in each spray module, for example, power supply 410 shown in
Another SWITCH 870 labeled “M” (MASTER) turns all of the valves (corresponding to individual switches 860) on or off with a single action. For example, at the end of a spray row, switch 870 can be used to shut all valves at once, and conversely to switch all of them back on to begin spraying the next row.
In an embodiment, a cable, for example, a three-conductor electrical cable 1034a, 1034b may be provided on the sprayer extending from the junction box to each one of the spray modules 200. Four modules are shown for illustration, two of them on each of two booms, 102a and 102b. The cable may provide ground, hot, and valve control connections. (See valve control signal 332 above). The hot DC voltage (and ground) may be provided, for example, by a battery (not shown). It may be provided by a tractor or other vehicle battery. In some embodiments, there may be additional connections (or communication signals) provided between the junction box and the spray modules. For example, a high voltage level control or a current limit alarm feedback (both illustrated in
It will be obvious to those having skill in the art that many changes may be made to the details of the above-described embodiments without departing from the underlying principles of the invention. The scope of the present invention should, therefore, be determined only by the following claims.
Most of the equipment discussed above comprises hardware and associated software. For example, the typical electronic device is likely to include one or more processors and software executable on those processors to carry out the operations described. We use the term software herein in its commonly understood sense to refer to programs or routines (subroutines, objects, plug-ins, etc.), as well as data, usable by a machine or processor. As is well known, computer programs generally comprise instructions that are stored in machine-readable or computer-readable storage media. Some embodiments of the present invention may include executable programs or instructions that are stored in machine-readable or computer-readable storage media, such as a digital memory. We do not imply that a “computer” in the conventional sense is required in any particular embodiment. For example, various processors, embedded or otherwise, may be used in equipment such as the components described herein.
Memory for storing software again is well known. In some embodiments, memory associated with a given processor may be stored in the same physical device as the processor (“on-board” memory); for example, RAM or FLASH memory disposed within an integrated circuit microprocessor or the like. In other examples, the memory comprises an independent device, such as an external disk drive, storage array, or portable FLASH key fob. In such cases, the memory becomes “associated” with the digital processor when the two are operatively coupled together, or in communication with each other, for example by an I/O port, network connection, etc. such that the processor can read a file stored on the memory. Associated memory may be “read only” by design (ROM) or by virtue of permission settings, or not. Other examples include but are not limited to WORM, EPROM, EEPROM, FLASH, etc. Those technologies often are implemented in solid state semiconductor devices. Other memories may comprise moving parts, such as a conventional rotating disk drive. All such memories are “machine readable” or “computer-readable” and may be used to store executable instructions for implementing the functions described herein.
A “software product” refers to a memory device in which a series of executable instructions are stored in a machine-readable form so that a suitable machine or processor, with appropriate access to the software product, can execute the instructions to carry out a process implemented by the instructions. Software products are sometimes used to distribute software. Any type of machine-readable memory, including without limitation those summarized above, may be used to make a software product. That said, it is also known that software can be distributed via electronic transmission (“download”), in which case there typically will be a corresponding software product at the transmitting end of the transmission, or the receiving end, or both.
Having described and illustrated the principles of the invention in a preferred embodiment thereof, it should be apparent that the invention may be modified in arrangement and detail without departing from such principles. We claim all modifications and variations coming within the spirit and scope of the following claims.
| Number | Name | Date | Kind |
|---|---|---|---|
| 5593134 | Steber | Jan 1997 | A |
| 6138922 | Hartman | Oct 2000 | A |
| 8016215 | Zhadanov | Sep 2011 | B1 |
| 20160318045 | Huffington | Nov 2016 | A1 |
| Number | Date | Country | |
|---|---|---|---|
| 20180361405 A1 | Dec 2018 | US |
