초록 ▼

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 an

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.

대표청구항 ▼

[ We claim:] [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

[ We claim:] [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; anda 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.