Diaphragm valve with filter screen and movable wiper element

• US 5,996,608 A
• Filed: 07/31/1998
• Issued: 12/07/1999
• Est. Priority Date: 07/31/1998
• Status: Expired due to Term

• Current Assignee: Hunter Industries Incorporated
• Original Assignee: Hunter Industries Incorporated
• Inventors: Hunter, Richard E., Hunter, Revis R.
• Primary Examiner(s): Walton, George L.
• Application Number:
  US09/127,017
• Time in Patent Office: 494 Days
• Field of Search: 137/549, 137/550, 137/242, 137/244, 137/547, 210/391, 210/395, 210/396, 210/413, 210/429, 210/432, 210/354, 210/355, 210/390, 210/407, 210/415, 210/431, 251/30.01, 251/30.02, 251/30.05, 251/45, 251/46
• US Class Current: 137/244
• CPC Class Codes: F16K 31/402 acting on a diaphragm
• CPC Class Codes: Y10T 137/4336 Cleaning member reciprocates in passage
• CPC Class Codes: Y10T 137/8049 Movable strainer
• CPC Class Codes: Y10T 137/8085 Hollow strainer, fluid inlet and outlet perpendicular to each other

Abstract

A diaphragm-type control valve for irrigation systems has an outer clam-shell housing that encloses a vertically reciprocable diaphragm assembly. A primary valve seat inside the housing is engaged and disengaged by a seal on the underside of the diaphragm to open and close the valve by connecting and disconnecting its inlet and outlet passages. Pressurized water from a lower inlet chamber of the valve travels through a small metering orifice in the center of the diaphragm assembly to an upper pressure control chamber above a flexible membrane of the diaphragm assembly. A solenoid actuated pilot valve is operatively coupled to the upper pressure control chamber for venting pressurized water therefrom to permit the diaphragm assembly to move upwardly to open the valve. A filter screen is mounted to the underside of the diaphragm assembly to prevent debris from clogging the metering orifice, clogging the small passages of the pilot valve, or fouling the solenoid. A cylindrical wiper element supported by a cylindrical carrier surrounds the filter screen and is moved up and down along the filter screen as the valve opens and closes to scour algae, mineral deposits and other debris from the surface of the filter screen which are carried away through the main outlet passage of the valve.

Claims

1. A diaphragm valve, comprising:

a valve housing having an inlet passage, an outlet passage, a primary valve seat between the inlet passage and the outlet passage, a lower inlet chamber below the primary valve seat, and an upper pressure control chamber above the primary valve seat;

a pilot valve operatively associated with the upper pressure control chamber for selectively venting pressurized water therefrom;

a diaphragm assembly mounted inside the valve housing and having a seal normally engaged with the primary valve seat to seal the inlet passage from the outlet passage, the diaphragm assembly being moveable in a first direction to disengage the seal from the primary valve seat upon release of a sufficient amount of pressurized water from the upper pressure control chamber, the diaphragm assembly including means for metering water from the lower inlet chamber through the diaphragm assembly into the upper pressure control chamber; and

a longitudinally extending filter assembly located inside the lower inlet chamber and coupled to the water metering means for removing debris from pressurized water before it passes from the inlet passage into the upper pressure control chamber through the water metering means, including a filter screen and a wiper element surrounding the filter screen and mounted for longitudinal reciprocation over an exterior surface of the filter screen to remove debris, the wiper element being floating and moved in the first direction by water flowing from the inlet passage to the outlet passage.

2. A diaphragm valve according to claim 1 wherein the filter assembly further includes spring means for moving the wiper element in a second direction opposite the first direction when water ceases flowing from the inlet passage to the outlet passage.

3. A diaphragm valve according to claim 1 wherein the filter assembly further includes a carrier surrounding the wiper element.

4. A diaphragm valve according to claim 1 wherein the filter screen is cylindrical.

5. A diaphragm valve according to claim 3 wherein the wiper element and carrier are both cylindrical.

6. A diaphragm valve according to claim 3 wherein the filter assembly further includes a spring surrounding the filter screen and positioned for compression between the carrier and the diaphragm assembly.

7. A diaphragm valve according to claim 1 wherein the wiper element is configured to have a rotational movement imparted to the same by the force of water flowing from the inlet passage to the outlet passage, the rotational movement of the wiper element being around a longitudinal axis of the filter screen.

8. A diaphragm valve according to claim 1 wherein the filter assembly further includes a support frame for holding the filter screen.

9. A diaphragm valve according to claim 8 wherein the support frame has at least one longitudinally extending guide rail and the wiper element has a corresponding longitudinally extending groove for receiving the guide rail to guide the wiper element through its longitudinal motion.

10. A diaphragm valve according to claim 1 wherein the wiper element has a plurality of scrubber elements each having a inner edge that engages the exterior surface of the filter screen.

11. A self-cleaning filter assembly for a valve having a vertically reciprocal diaphragm assembly that separates a lower inlet chamber from an upper pressure control chamber vented by a pilot valve, the diaphragm assembly including a metering orifice, the filter assembly comprising:

a filter screen connected to the diaphragm assembly and located in the inlet chamber for preventing debris from entering the metering orifice; and

a free floating wiper element moveable in an upward direction along an exterior surface of the filter screen by the flow of water through the valve when the valve is open for scouring debris from the exterior surface.

12. A filter assembly according to claim 11 and further comprising spring means for moving the wiper element in a downward direction when the valve is closed and water ceases flowing therethrough.

13. A filter assembly according to claim 11 and further comprising a carrier surrounding the wiper element.

14. A filter assembly according to claim 11 wherein the filter screen is cylindrical.

15. A filter assembly according to claim 13 wherein the wiper element and carrier are both cylindrical.

16. A filter assembly according to claim 13 and further comprising a spring surrounding the filter screen and positioned for compression between the carrier and the diaphragm assembly.

17. A filter assembly according to claim 11 wherein the wiper element is configured to have a rotational movement imparted to the same by the force of water flowing through the valve, the rotational movement of the wiper element being around a longitudinal axis of the filter screen.

18. A filter assembly according to claim 11 and further comprising a support frame for holding the filter screen, the support frame having at least one longitudinally extending guide rail and the wiper element having a corresponding longitudinally extending groove for receiving the guide rail to guide the wiper element through its longitudinal motion.

19. A filter assembly according to claim 11 wherein the wiper element has a plurality of radially inwardly directed scrubber elements each having a inner edge that engages the exterior surface of the filter screen.

20. A diaphragm valve, comprising:

a valve housing having an inlet passage, an outlet passage, a primary valve seat between the inlet passage and the outlet passage, a lower inlet chamber below the primary valve seat, and an upper pressure control chamber above the primary valve seat;

a pilot valve coupled to the upper pressure control chamber for selectively venting pressurized water therefrom;

a diaphragm assembly mounted inside the valve housing and having an outer seal normally engaged with the primary valve seat to seal the inlet passage from the outlet passage, the diaphragm assembly being moveable in a first direction to disengage the seal from the primary valve seat and open the valve upon release of a sufficient amount of pressurized water from the upper pressure control chamber through actuation of the pilot valve, the diaphragm assembly being moveable in a second direction opposite the first direction to close the valve upon further actuation of the pilot valve to cause the build-up of sufficient pressure inside the upper pressure control chamber, the diaphragm assembly including means for metering water from the lower inlet chamber through the diaphragm assembly into the upper pressure control chamber; and

a longitudinally extending filter assembly located inside the lower inlet chamber and coupled to the water metering means for removing debris from pressurized water before it passes from the lower inlet chamber into the upper pressure control chamber through the water metering means, including a filter screen, a wiper element surrounding the filter screen and mounted for longitudinal reciprocation over an exterior surface of the filter screen to remove debris, a carrier surrounding and supporting the wiper element, and a spring compressed between the carrier element and the diaphragm assembly, the carrier and wiper element being free floating and moved in the first direction by water flowing from the inlet passage to the outlet passage when the valve is open, and the wiper element and carrier being moved in the second direction when the valve closes.

21. A valve, comprising:

a valve member;

a valve housing having an inlet passage and an outlet passage, the valve member being reciprocable back and forth within the valve housing to thereby connect and disconnect the inlet passage and the outlet passage, the valve housing having a lower inlet chamber below the valve member, and an upper pressure control chamber above the valve member;

a pilot valve operatively associated with the upper pressure control chamber for selectively venting pressurized water therefrom;

the valve member normally sealing the inlet passage from the outlet passage and being moveable in a first direction to connect the inlet passage with the outlet passage upon release of a sufficient amount of pressurized water from the upper pressure control chamber;

the valve member including means for metering water from the lower inlet chamber through the valve member into the upper pressure control chamber; and

a longitudinally extending filter assembly located inside the lower inlet chamber and coupled to the water metering means for removing debris from pressurized water before it passes from the inlet passage into the upper pressure control chamber through the water metering means, including a filter screen and a wiper element surrounding the filter screen and mounted for longitudinal reciprocation over an exterior surface of the filter screen to remove debris, the wiper element being free floating and moved in the first direction by water flowing from the inlet passage to the outlet passage.

22. A valve according to claim 21 wherein the filter assembly further includes spring means for moving the wiper element in a second direction opposite the first direction when water ceases flowing from the inlet passage to the outlet passage.

23. A valve according to claim 21 wherein the filter assembly further includes a carrier surrounding the wiper element.

24. A valve according to claim 21 wherein the filter screen is cylindrical.

25. A valve according to claim 23 wherein the wiper element and carrier are both cylindrical.

26. A valve according to claim 23 wherein the filter assembly further includes a spring surrounding the filter screen and positioned for compression between the carrier and the valve member.

27. A valve according to claim 21 wherein the wiper element is configured to have a rotational movement imparted to the same by the force of water flowing from the inlet passage to the outlet passage, the rotational movement of the wiper element being around a longitudinal axis of the filter screen.

28. A valve according to claim 21 wherein the filter assembly further includes a support frame for holding the filter screen.

29. A valve according to claim 28 wherein the valve member is a diaphragm assembly.

30. A diaphragm valve according to claim 21 wherein the valve member is a piston.