Anti-siphon ball cock assembly

Claim 1

IN AN ANTI-SIPHON BALL COCK ASSEMBLY WHICH INCLUDES AN UPRIGHT STANDPIPE AND A VALVE CASING, SAID CASING INCLUDING A BOWL MOUNTED ON THE UPPER END OF SAID STANDPIPE AND HAVING AN ANNULAR CHAMBER PROVIDED WITH RADIALLY SPACED INNER AND OUTER WALLS, A TUBULAR VALVE SEAT MEMBER DISPOSED CONCENTRICALLY WITHIN SAID CHAMBER INNER WALL AND COMMUNICATING WITH SAID STANDPIPE, SAID BOWL HAVING AN UPPER END SURFACE POSITIONED ABOVE AND RADIALLY OUTWARDLY OF SAID CHAMBER AND A SUBSTANTIALLY HORIZONTAL SHOULDER DISPOSED BELOW AND RADIALLY INWARDLY OF SAID UPPER END SURFACE, SAID BOWL HAVING A WATER OUTLET COMMUNICATING WITH SAID CHAMBER BELOW THE UPPER END THEREOF AND AN OPENING TO ATMOSPHERE LOCATED RADIALLY OUTWARDLY OF SAID CHAMBER, AN ANNULAR FLAPPER VALVE FORMED OF A RESILIENT MATERIAL AND HAVING A RADIALLY OUTER EDGE PORTION SUPPORTED ON SAID SHOULDER, A DIAPHRAGM SUPPORTED ON SAID RADIALLY OUTER EDGE PORTION OF SAID FLAPPER VALVE FOR MOVEMENT INTO ENGAGEMENT WITH THE UPPER END OF SAID SEAT MEMBER, A TOP WALL MEMBER FOR SAID CASING SUPPORTED ON THE UPPER END SURFACE OF SAID BOWL IN ENGAGEMENT WITH SAID DIAPHRAGM AT A POSITION IN VERTICAL ALIGNMENT WITH SAID SHOULDER, A NUT THREADABLY MOUNTED ON SAID BOWL AND ENGAGED WITH SAID TOP WALL MEMBER FOR MAINTAINING SAID TOP WALL MEMBER IN ENGAGEMENT WITH SAID TOP BOWL SURFACE IN A POSITION IN WHICH THE DIAPHRAGM AND THE FLAPPER VALVE ARE CLAMPED BETWEEN SAID TOP WALL MEMBER AND SAID SHOULDER, STOP MEANS ON SAID SEAT MEMBER PROJECTING RADIALLY OUTWARDLY ADJACENT THE UPPER END OF SAID CHAMBER FOR ENGAGEMENT WITH THE INNER EDGE PORTION OF SAID FLAPPER VALVE TO DEFINE A POSITION OF SAID FLAPPER VALVE IN WHICH SAID CHAMBER COMMUNICATES WITH SAID OPENING, SAID FLAPPER VALVE INNER EDGE PORTION BEING PROVIDED WITH A PLURALITY OF SLITS WHICH EXTEND RADIALLY OUTWARDLY FROM SAID INNER EDGE PORTION BEYOND THE RADIALLY OUTER EDGE OF SAID CHAMBER AND BEING MOVABLE DOWNWARDLY IN RESPONSE TO A FLOW OF WATER INTO SAID BOWL FROM SAID SEAT MEMBER TO A POSITION IN WHICH SAID FLAPPER VALVE ENGAGES THE RADIALLY OUTER EDGE OF SAID CHAMBER SO AS TO BLOCK COMMUNICATION OF THE CHAMBER AND SAID OPENING AND PROVIDE FOR COMMUNICATION OF SAID CHAMBER WITH SAID SEAT MEMBER AND SAID OUTLET.