Elastic ball check valve

Claim 1

A CHECK VALVE COMPRISING A VALVE HOUSING HAVING A FLUID PASSAGE THERETHROUGH DEFINED IN PART BY A SMOOTH WALLED CYLINDRICAL BORE WHICH OPENS AT ONE END INTO AN ENLARGED CHAMBER, AN ELASTIC BALL CHECK IN SAID PASSAGE MOVABLE BETWEEN A CLOSED POSITION IN SAID BORE AND AN OPEN POSITION IN SAID CHAMBER, SAID BALL BEING RECEIVABLE INTO SAID BORE AND BEING ELASTICALLY EXPANDABLE TO FORM A SEAL THEREIN, AND SAID BALL HAVING A DIAMETER WHICH IS APPRECIABLY LESS THAN THE CROSS-SECTIONAL DIMENSIONS OF SAID CHAMBER, STOP MEANS IN SAID CHAMBER TO LIMIT OPENING MOVEMENT OF THE BALL IN THE CHAMBER IN A DIRECTION AWAY FROM SAID BORE, AND AT LEAST ONE CROSS PIN EXTENDING ACROSS THE MEDIAL PORTION OF SAID BORE WITHIN THE CYLINDRICAL WALL PORTION THEREOF TO FORM AN ABUTMENT THEREIN WHICH PREVENTS EXTRUSION OF THE BALL THROUGH THE BORE AND LIMITS CLOSING MOVEMENT OF THE BALL THEREIN, AND WHICH, WHEN THE BALL IS FORCED THEREAGAINST BY FLUID PRESSURE, FORMS A DEPRESSION IN THE BALL IN THE MEDIAL REGION OF THE BORE AND A CONSEQUENT COMPRESSION IN THE CENTER REGION OF THE BALL SUCH AS TO THRUST THE BALL OFF SAID PIN WHEN SAID FLUID PRESSURE IS RELIEVED.