Pilot operated valve assembly

Claim 1

A pilot-operated valve having a relatively simply molded plastic diaphragm insert, the pilot-operated valve comprising: (a) a valve housing which defines a fluid inlet in fluid communication with an annular inlet cavity, a valve seat generally central in the annular inlet cavity, and a fluid outlet extending through the valve seat; (b) a flexible diaphragm having an annular seating portion disposed in a fluid sealing relationship with the valve housing surrounding the annular inlet cavity, a flexible web portion extending peripherally inward from the annular seating portion for permitting movement of the diaphragm relative to the valve housing, a diaphragm peripheral portion disposed peripherally inward from the web portion for mechanically engaging the diaphragm insert, and a diaphragm central portion disposed radially inward from the diaphragm peripheral portion, the diaphragm central portion (i) having a first side which is disposed for selectively contacting the valve seat to form a sealing relationship therewith, (ii) defining a plurality of filtering apertures therethrough adjacent the diaphragm peripheral portion in fluid communication with the annular inlet cavity, and (iii) defining a central aperture therethrough in fluid communication with the fluid outlet; (c) the diaphragm insert having a first side, an oppositely disposed second side which is disposed adjacent the diaphragm central portion, and a peripheral edge disposed peripherally around the diaphragm insert between the first and second sides and in firm frictional contact with said diaphragm peripheral portion, the insert defining: (i) a pilot outlet aperture centrally therethrough in communication with the diaphragm central aperture and the valve outlet, (ii) a peripheral recess extending inward from both the insert peripheral edge and the insert second side such that the peripheral recess is moldable by a radially inward projection of a split mold block which is adapted to move generally parallel with the first and second insert sides, the insert peripheral recess being disposed in alignment and fluid communication with the diaphragm filtering apertures for conveying filtered fluid therefrom, (iii) a pilot supply aperture extending therethrough between the first side and the peripheral recess such that the peripheral recess is in fluid communication with both the pilot inlet aperture and the diaphragm filter apertures, whereby the peripheral recess provides fluid communication between the filter apertures and the pilot aperture without complex, multipiece molding arrangements; (d) means operatively connected with the diaphragm annular seating portion for defining a pilot reservoir in fluid communication with the pilot inlet and outlet apertures; and, (e) pilot valve means operatively connected with the pilot outlet aperture for selectively opening and closing the pilot outlet aperture.