Improved valve-controlled atomization system

Abstract

A liquid spray system having a liquid spray unit and a control unit for controlling the liquid to the spray unit, the control unit including a valve operable between a plurality of positions for controlling the supply of liquid to the spray unit, and allowing the flow of liquid from the spray unit to the backflow line only after the supply of liquid to the spray unit has terminated.

Description

[Background technology]

[0001] [CROSS-REFERENCE TO RELATED APPLICATIONS]

[0002]

[0001] This patent application claims the benefit of U.S. Provisional Patent Application No. 62 / 976,892, filed February 14, 2020, which is incorporated herein by reference.

[0003] [Field of the Invention]

[0004] This invention relates generally to valve controlled spray systems and, more particularly, to an improved valve system for controlling the flow of liquid to a spray nozzle during operation and when the liquid supply is shut off.

[0005] [Background of the invention]

[0006]

[0003] Agricultural sprayers typically have a long spray boom with groups of spray nozzles selectively controlled by respective control valves, each individually actuated to allow delivery or termination of liquid to the spray nozzles of the group. Termination of liquid to one or more groups of spray nozzles is often necessary near the edge of a field, for example, to prevent spraying of non-crop vegetation. The control valves for such spray systems are generally ganged or manifolded and mounted in side-by-side relationship with each other and at locations remote from the spray nozzles they control. Each control valve includes a valve element movable between an open position and a closed position to selectively control the flow of liquid to the spray nozzles of its respective group.

[0007] It is known that control valves include ball valves that are rotatable between one position, which allows the direction of pressurized liquid through the control valve into a liquid supply line to a spray nozzle or group of spray nozzles, and a second position, which closes the liquid inlet port of the valve and redirects any downstream liquid remaining in the line to a return line for recirculation to a liquid supply tank. However, while the ball valve rotates to the closed position, the liquid inlet port does not completely close before the port to the return line opens, resulting in a spurt of high-pressure liquid through the control valve before the inlet port completely closes. In today's sophisticated agricultural sprayers, liquid directed to the field is often monitored by the amount of liquid directed to the spray nozzle, and the redirection of liquid to the return line before the valve shuts off affects the accuracy of monitoring the use of liquid chemicals. While proposals have been made to prevent such occurrences, such proposals are relatively complex and expensive, and require multiple valve mechanisms. OBJECTIVES AND SUMMARY OF THE INVENTION

[0008] SUMMARY OF THE INVENTION It is an object of the present invention to provide a valve-controlled spray system that allows for more efficient and accurate monitoring of the liquid supplied to the sprayer based on the liquid inlet feed.

[0009]

[0006] Another object of the present invention is to provide a valve-controlled spray system as characterized above that is operable to cut off the liquid supply to the spray nozzle without causing an undesirable burst of liquid through the control valve which could affect accurate monitoring of chemical usage.

[0010]

[0007] A further object is to provide a valve-controlled spray system of the above type having a liquid supply control valve operable to completely shut off the liquid supply to the spray nozzle before directing the liquid downstream in the spray nozzle feed line to the return line to the liquid supply.

[0011] Another object is to provide a valve control system of the above type which is relatively simple in construction and operation and which lends itself to economical manufacture and reliable use.

[0012] Other objects and advantages of the present invention will become apparent upon reading the following detailed description and upon reference to the drawings. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a schematic diagram of an exemplary spray system having a control valve according to the present invention. [Figure 2] FIG. 2 is an enlarged fragmentary portion of one of the spray nozzle assemblies and associated check valves included in the spray system shown in FIG. 1, showing the check valve in a closed position. [Figure 3] FIG. 3 is an enlarged fragmentary portion of an exemplary check valve showing the check valve in an open position. [Figure 4] FIG. 4 is an enlarged vertical cross-section of one of the illustrated control modules taken in a plane perpendicular to the central liquid port of the control module, showing the valve stem in an open position to transmit liquid from the central liquid supply port to the outlet port of the control valve. [Figure 5] FIG. 5 is a vertical cross section similar to FIG. 4 but showing the valve stem in a lowered position, which blocks the flow of liquid from the liquid supply port to the outlet port and spray nozzle while leaving the backflow or return port open in communication with the return line. [Figure 6] FIG. 6 is a vertical cross section of the control module shown in FIG. 5, taken in a plane perpendicular to the plane of FIG. [Figure 7] FIG. 7 is a partial cross-section of a control module similar to FIG. 4, showing the valve stem in an open position, allowing liquid to communicate through the outlet port to the spray nozzle. [Figure 8] FIG. 8 is a view similar to FIG. 7, but with the valve stem in an intermediate position, blocking liquid flow to the liquid outlet port to the spray nozzle and to the reverse or return port of the module. [Figure 9]FIG. 9 is a partial cross-sectional view similar to FIGS. 5 and 6 showing the valve stem in a lowered position, but blocking the flow of liquid through the inlet port and allowing reverse or return flow of liquid to the return port. [Figure 9A] FIG. 9A is an enlarged blow-up view of the lower valve stem of FIG. [Figure 10] FIG. 10 is an enlarged perspective view of the electric motor and valve stem driver of the exemplary control module. [Figure 11] FIG. 11 is an enlarged horizontal cross-section of the control module taken at the plane of line 11-11 in FIG. [Figure 12] FIG. 12 is a side view of the electric motor and valve stem driver of the exemplary control module. [Figure 13] FIG. 13 is a cross section of the motor and valve stem drive taken in the plane of line 13-13 of FIG.

[0014]

[0024] While the present invention is susceptible to various modifications and alternative constructions, specific illustrated embodiments thereof are shown in the drawings and are described in detail below. It should be understood, however, that there is no intention to limit the invention to the disclosed structural forms. On the contrary, the intention is to cover all modifications, alternative constructions, and equivalents falling within the spirit and scope of the invention. Thus, while the present invention will be described in the context of a kit-mounted control valve for a pesticide spray system, it will be understood that the invention is equally applicable to control valves for other types of liquid spray or transfer systems.

[0015] Detailed Description of the Preferred Embodiments

[0016]

[0025] 1 of the drawings, there is shown an exemplary agricultural spraying system 10 including a supply tank 11 containing a quantity of liquid to be sprayed, a plurality of spraying sections 12 each having a plurality of spray nozzles 14 through which the liquid is discharged, and a group of sprayer control valves 15 according to the present invention, which spray control valves 15 are ganged or manifolded together and mounted alongside one another and adapted to control the flow of liquid from the supply tank 11 to the spraying sections 12. Essentially, the spraying system 10 is similar to that disclosed in the above-cited U.S. Pat. No. 6,036,107, the disclosure of which is incorporated herein by reference.

[0017]

[0026] As is conventional in agricultural sprayers, the spraying system 10 includes supply lines 18 between the supply tank 11 and the group of control valves 15 for conveying liquid to the control valves 15, discharge lines 19 between each control valve 15 and the respective spraying section 12 for delivering liquid to the spraying section, return lines 20 providing return communication between the control valves 15 and the supply tank 11, and regulating lines 21 having regulating valves 22 between the group of control valves 15 and the supply tank 11 for facilitating regulation of system pressure.

[0018]

[0027] The supply line 18 of the illustrated spray system 10 includes a shutoff valve 24, which allows for manual stopping of the flow of liquid from the supply tank 11, a pump 25, which pressurizes the liquid in the supply line 18, a strainer 26, which filters debris from the supply line 18, and a throttle valve 28, which allows for manual flow adjustment. The supply line 18 also includes a return line 29, which in this case branches off from the supply line 18 at a point downstream of the pump 25 and returns to the supply tank 11. As shown in FIG. 1 , the return line 29 includes an agitator 30, which is located within the supply tank 11 and mixes the liquid in the supply tank 11 based on the flow rate through the return line 29. The return line 29 also includes a throttle valve 31, which can be manually adjusted to regulate the flow rate through the return line 20 and thus the mixing speed of the agitator 30. The illustrated spray system 10 includes a computer-operated sprayer controller 35 operatively connected to each of the groups of control valves 15 and regulator valves 22 in a known manner.

[0019]

[0028] As depicted in FIGS. 2 and 3 , the illustrated spray nozzles 14 may be conventional, each having a nozzle body 38 with a stem 39 supported in fluid communication with a liquid supply boom 40 of the spray section 12, which in turn is coupled to a respective supply line 19. Each spray nozzle 14 has a respective check valve 41, such as that disclosed in commonly assigned U.S. Pat. No. 4,660,598. When the pressure of liquid delivered to the spray nozzle 14 via the supply line 19 exceeds the force of a biasing spring 42, the pressurized liquid biases a diaphragm 45 away from the upstream end 46 of an inlet tube 48, as shown in FIG. 3 , allowing the liquid to flow through the inlet tube 48 and be expelled from the spray nozzle. When the pressurized liquid is cut off from the supply source, the spring 42 forces the diaphragm into sealing engagement with the upstream end of the tube 48, preventing further liquid from being expelled or dripping from the spray nozzle 14.

[0020]

[0029] The control valves 15 of the spray section 12 each have a modular construction and are ganged or manifolded together in a manner similar to that disclosed in the aforementioned U.S. Patent No. 6,036,107. As shown in FIGS. 4-6, the control valve 15 includes a main valve body 50, a lower valve body 51 supported below the main valve body 50, and an electric valve control motor 52 supported above the main valve body 50. In this case, the main valve body 50 has an upwardly opening annular collar 54 that receives and supports an annular mounting portion 55 of the motor 52 housing via an annular sealing ring 56. The lower valve element 51 has an upwardly extending reduced-diameter hub portion 58 supported within the lower end of the main valve body 50 via a sealing O-ring 59. The main valve body 50 includes a central, lateral-facing main liquid supply port 60 for receiving liquid from the supply line 18, and the lower valve body 51 has a central vertical liquid passage 62 for communicating with the liquid supply port 60. The central vertical passage 62 in turn communicates with a cross passage 64 having a liquid outlet port 65 and a reduced downstream backflow or return port 66 adjacent the lower end of the valve body 51. The control valve 15 is associated with a plurality of interconnected control valve liquid supply ports 60 and liquid supply lines 18, with each liquid outlet port 65 coupled to a respective liquid supply line 19 to the spray section 12 and each liquid backflow or return port 66 coupled to the return line 20.

[0021]

[0030] In accordance with an important feature of this embodiment, each control valve 15 has a single valve stem 70 that controls the flow of liquid from the main liquid supply port 60 to the outlet port 65 and respective supply line 19, as well as the liquid backflow or return port 66 and return line 20. To this end, the valve stem 70 extends centrally through the main valve body 50, the liquid supply port 60, and the central liquid supply passage 62 of the lower valve body 51. In this case, the valve stem 70 extends the entire length of the main valve body 50 and the lower valve body 51, with its lower end positionable through the lower backflow or return port 66. An annular seal 71 is supported around the lower end of the valve stem 70 (FIG. 9A) to seal against contact with the reduced-diameter backflow or return port 66, as described below. For ease of manufacture, the valve stem 70 in this case has an upper portion 70a and a lower portion 70b securely fastened to one another by a threaded fitting 72.

[0022]

[0031] To control the supply of liquid from the liquid supply port 60 to the central passage 62 and outlet port 65 of each spray nozzle 14, an annular seal 75 is supported on a rod 70 within the main liquid supply port 60, as depicted in Figure 4. The main annular seal 75 is biased downwardly against an E-clip 76 secured to the rod 70 by a coil spring 78 interposed between an upper washer 79 of the annular seal 75 and an upper E-clip 80 secured to the rod above the washer 79. In this case, an O-ring seal 81 is mounted in circumferential relationship to the valve stem 70 within the annular seal 75.

[0023]

[0032] An electric motor 52 is operatively coupled to the valve stem 70 to raise and lower the valve stem 70 between open and closed positions. To this end, the electric motor 52 may be a 12V DC reversible motor having a drive shaft 85 coupled to a drive train 86 for rotating an output shaft 88 supported in response to the drive train 86 above the valve stem 70. To facilitate controlled raising and lowering of the valve stem 70 as the output shaft 88 rotates, an optical switch flag 89 attached to the upper end of the valve stem 70 is threadedly supported on a threaded portion 90 of the output shaft 88. The switch flag 89 is rotationally supported such that driving rotation of the output shaft 88 raises and lowers the switch flag 89 and the valve stem 70 coupled to its underside relative to the valve bodies 50 and 51. To guide the raising and lowering of the switch flag 89, and thus the valve stem 70, a lateral leg 89a on one side of the flag switch 89 is guided to move within a guide track 92 fixed within the motor housing (FIG. 11).

[0024]

[0033] The switch flag 89 has a thin leg portion 89b opposite the guide flag portion 89a to control the up and down movement of the valve stem 70, and is movable with the valve stem 70 between optical sensors 95a, 95b which control the electric motor 52 to limit the up and down movement of the switch flag 89, which becomes the valve stem 70. In this case, the optical sensors 95a and 95b are coupled to a circuit board 96 (FIG. 10) which, through appropriate operator controls, effects the operation of the electric motor 52 and the movement of the valve stem 70 between the sensors 95a, 95b.

[0025]

[0034] In accordance with a further important aspect of this embodiment, each control valve 15 is operable such that the valve stem 70 is fully closed to seal communication between the main liquid inlet port 60 and the central passage 62, from the outlet port 65 to the atomizing section 12, and then to allow communication from the outlet port 65 and the supply line 19 to the reverse or return port 66. As depicted in FIGS. 4 and 7 , when the electric motor 52 rotates the output shaft 88 to raise the flag switch 89 and associated valve stem 70 to an upper position with the flag switch portion 89b contacting the upper optical sensor 95a, the annular seal 75 carried by the valve stem 70 is raised to an open position allowing communication of liquid from the main liquid inlet port 60 of the control module to the central and cross passage portions 62, 65 and the output port 65 to the atomizing system 12. A lower E-clip 76 carries and supports the annular seal 75 in such raised or open position. At the same time, the lower end of the valve stem 70 is raised and positioned in a closed position within the reverse flow or return port 66, and the annular seal 71 prevents the passage of liquid from both the central passage 62 and the outlet port 60 to the reverse flow or return port 66.

[0026]

[0035] To prevent fluid communication to the outlet port 65 and atomizing section 12, the electric motor 52 is operated in reverse under the control of the circuit board 96, rotating the output shaft 88 in the reverse direction and lowering the optical switch flag 89 and valve stem 70 downward to an intermediate position that initially closes both liquid inlet ports 60 while the reverse flow and return ports 66 remain closed, as shown in FIG. 8 . It can be seen that in such intermediate position, the annular seal 75 is biased into a position that closes the inlet port 60, while the lower valve stem 70 continues to close the reverse flow port 66. Continued operation of the drive motor 52 and rotation of the output drive shaft 88 further lowers the valve stem 70 a sufficient distance so that the annular seal 71 at the lower end of the valve stem 70 is positioned beyond the reduced-diameter reverse flow or return port 66. During such movement, the annular seal 75 remains biased by the biasing spring 78 in its closed position, and the E-clip 76 supporting the valve stem 70 and the annular seal 75 continues to move downward with the valve stem 70 (FIGS. 6 and 9). When the valve stem 70 and optical switch flag 89 are lowered to a height where the flag portion 89b contacts the lower optical sensor 95b, the lower end of the valve stem 70 and the annular seal 65 are positioned beyond the reduced-diameter outlet or return port 66, thereby allowing downstream liquid to be discharged back into the return line 20 through the backflow outlet 66. Because the inlet port 60 is fully closed before opening the backflow or return port 66, it will be appreciated that while liquid is blocked to the spray section 12, there is no burst or other communication of liquid from the inlet port 60 to the return port 66 and return line 15, or any other appreciable loss of supplied liquid that would significantly affect reliable monitoring of liquid chemicals, etc.

[0027]

[0036] To resume spraying, drive motor 52 can be operated in the reverse direction to first raise switch flag 89 and valve stem 70 to a position that closes backflow or return port 66 while annular seal 75 remains biased to a position that closes inlet port 60, and then valve stem 70 can continue to rise until optical switch flag portion 89b engages upper optical sensor 95a. Such further movement causes E-clip 76 to lift annular seal 75, opening main liquid supply port 60 and communicating liquid to spray portion 12, as shown in FIG.

[0028]

[0037] From the foregoing, it can be seen that a valve-controlled spray system is provided that is operable to shut off and turn on the liquid supply to the spray nozzle without causing undesirable bursts of liquid through the control valve that can affect accurate monitoring of liquid chemical usage. The valve system utilizes a single valve stem that is controlled to completely shut off the liquid to the spray nozzle before allowing the liquid to drain into the spray system return line. It can also be seen that the valve control system is relatively simple in construction and operation, lending itself to economical manufacture and reliable use.

Claims

1. A liquid spray system (10) for spraying pesticides, comprising: a liquid spray section (12) having at least one spray nozzle (14); a liquid control device for controlling the flow of liquid from a pesticide liquid supply (11) to the sprayer for discharge from the at least one spray nozzle (14), the liquid control device including a liquid control valve (15) having a valve body (50, 51) with a liquid supply port (60), a liquid outlet port (65), and a liquid backflow port (66); a first liquid supply line (18) that guides liquid from the liquid supply section (11) to the liquid supply port (60); a second liquid supply line (19) that guides liquid from the liquid supply port (60) to the spray section (12); a backflow line (20) coupled to the backflow port (66) for directing liquid in the second liquid supply line (19) away from the spray section (12) when the supply of liquid to the spray section (12) is terminated; Equipped with The control valve (15) has a valve stem (70); The control valve (15) is operable to move the valve stem (70) between (1) a first position, (2) a second position, and (3) a third position; the first position opens the liquid supply port (60) to allow the direction of liquid from the first liquid supply line (18) through the liquid supply port (60) and liquid outlet port (65) to the second liquid supply line (19) and the liquid spray portion (12) to emit from the at least one spray nozzle (14) while blocking the flow of liquid to the backflow line (20) through the backflow port (66); the second position blocks the supply of liquid from the first liquid supply line (18) through the liquid supply port (60) to the liquid outlet port (65) and the second liquid supply line (19) while continuing to block the flow of liquid through the reverse flow port (66) to the reverse flow line (20); In the third position, while the valve stem (70) is moving to the third position, it continues to block the flow of liquid from the first liquid supply line (18) through the liquid supply port (60) and the liquid outlet port (65), while opening the backflow port (66) to allow liquid remaining in the second liquid supply line (19) to flow back through the backflow port (66) and the backflow line (20) such that liquid flow from the second liquid supply line (19) to the backflow line (20) is only possible when the liquid supply port (60) is closed.

2. 2. The liquid spray system of claim 1, wherein the valve stem extends through both the liquid supply port and the reverse flow port, and in the first position, allows liquid to flow from the liquid supply port and the liquid outlet port to the second liquid supply line while blocking flow through the reverse flow port; in the second position, simultaneously blocks liquid flow through both the liquid supply port and the reverse flow port; and when the valve stem moves to the third position, continues to block liquid flow through the liquid supply port while simultaneously opening the reverse flow port to allow liquid remaining in the second liquid supply line to flow to the reverse flow line.

3. 2. The liquid spray system of claim 1, wherein the valve stem is threadably supported for relative longitudinal movement within the valve body, and includes a motor coupled to the valve stem for selectively rotating the valve stem to move the valve stem between the first position, the second position, and the third position.

4. 4. The liquid spray system of claim 3, including a control device for controlling operation of the motor, the control device including: a switch carried by the valve stem for movement with the valve stem between the first, second, and third positions; and a pair of longitudinally spaced sensors on the valve body engageable by the switch to control operation of the motor and limit movement of the valve stem between the first and third positions.

5. 2. The liquid spray system of claim 1, wherein the valve stem (70) carries a first sealing member (75) that closes the liquid supply port (60) when the valve stem (70) is in the second position and the third position, and a second sealing member (71) that closes the backflow port (66) when the valve stem (70) is in the first position and the second position.

6. 6. The liquid spray system of claim 5, wherein the first sealing member is an annular sealing member attached to the valve stem and spring-biased for relative movement, and when the valve stem moves from the first position to the second and third positions, the first sealing member closes the liquid supply port while allowing continuous movement of the valve stem to the second and third positions.

7. The valve body (50, 51) has an elongated liquid passage (62) communicating between the liquid supply port (60) and the backflow port (66), the valve stem (70) is mounted for reciprocating movement within the elongated liquid passage (62) between the first position, second position, and third position, the second liquid supply line (19) communicates with the elongated liquid passage (62) at a location intermediate the liquid supply port (60) and the backflow port (66), and the valve stem (70) in the first position allows liquid to flow from the liquid supply port (60) through the elongated liquid passage (62) to the second liquid supply line (19) while simultaneously opening the backflow port (66).

2. The liquid spray system of claim 1, wherein in the second position, the switch blocks the flow of liquid through the liquid supply port (60) and simultaneously blocks the flow of liquid into the elongated liquid flow path (62) through the liquid supply port (60) and blocks the flow of liquid from the elongated liquid flow path (62) through the reverse flow port (66), and upon movement to the third position, the switch opens the reverse flow port (66) to allow liquid communication from the second liquid supply line (19) through the elongated liquid flow path (62) and the reverse flow port (66) to the reverse flow line (20), while continuing to block the flow of liquid from the liquid supply line (18) through the liquid supply port (60) to the elongated liquid flow path (62).

8. 2. The liquid spray system of claim 1, wherein the valve body has an elongated liquid passageway (62) communicating between the liquid supply port (60) and the backflow port (66), and the second liquid supply line (19) communicates with the elongated liquid passageway (62) at a location between the liquid supply port (60) and the liquid backflow port (66).

9. 9. The liquid spray system of claim 8, wherein the valve stem extends through the elongated liquid flow path and both the liquid supply port and the reverse flow port, and in the first position allows liquid flow from the liquid supply port to the liquid outlet port and the second liquid supply line while simultaneously blocking flow through the reverse flow port, and in the second position simultaneously blocks liquid flow through both the liquid supply port and the reverse flow port, and when the valve stem moves to the third position, continues to block liquid flow through the liquid supply port and then opens the reverse flow port to allow liquid remaining in the second liquid supply line to flow to the reverse flow line.

10. 10. The liquid spray system of claim 9, wherein the valve stem (70) is threadably supported for relative longitudinal movement within the valve body (50, 51), and includes a motor (52) coupled to the valve stem (70) for selectively rotating the valve stem (70) to move the valve stem (70) between the first position, the second position, and the third position.

11. 9. The liquid spray system of claim 8, wherein the valve stem (70) carries a first sealing member (75) that closes the liquid supply port (60) when the valve stem (70) is in the second position and the third position, and a second sealing member (71) that closes the backflow port (66) when the valve stem (70) is in the first position and the second position.

12. 12. The liquid spray system of claim 11, wherein the first sealing member (75) is attached to the valve stem (70) and is spring-biased for relative movement, such that when the valve stem (70) moves from the first position to the second position, the first sealing member (75) closes the liquid supply port (60) while allowing the valve stem (70) to continue moving to the second position and the third position.

13. 13. The liquid spray system of claim 12, wherein the valve stem carries a second sealing member (71) longitudinally spaced from the first sealing member (75), the second sealing member (71) blocking the flow of liquid through the reverse flow port to the reverse flow line when the valve stem is in the first position and the second position, and when the valve stem moves to the third position, the second sealing member (71) is carried by the valve stem to a position that opens the reverse flow port to allow liquid to flow from the second liquid supply line through the liquid outlet port and the reverse flow port to the reverse flow line.

14. 10. The liquid spray system of claim 1, a spray boom having a liquid flow path, the spray boom supporting a plurality of said spray nozzles, each having a discharge orifice in fluid communication with said liquid flow path of said spray boom; each one of the control valves controlling the flow of liquid from a liquid supply to the liquid flow path of the spray boom; A liquid spray system comprising:

Images