Capsule-type check valve

Claim 1

A SELF-ALIGNING, SELF-SEATING CHECK VALVE COMPRISING: (A) A CUP-SHAPED ELEMENT HAVING A BASE DEFINING A VALVE SEAT AN AXIAL CIRCULAR FLUID PASSAGEWAY EXTENDING THERETHROUGH, SAID ELEMENT BEING ADAPTED TO BE MOUNTED IN A FLUID PASSAGE, (B) A SPIDER INCLUDING A HUB PORTION HAVING AT LEAST ONE AXIALLY POSITIONED INTURNED FLANGE, A RIM PORTION MOUNTED IN THE MARGINAL PORTION OF SAID CUP-SHAPED MEMBER, AND SPOKES CONNECTING THE HUB AND RIM PORTIONS AND DEFINING PORTS OF LIQUID PASSAGE THERETHROUGH, (C) A CUP-SHAPED VALVE ELEMENT WHOSE CONVEX OUTER SIDES ARE SPHERICALLY CURVED AND WHOSE APEX IS FORMED INTO AN AXIAL PROJECTION, THE CONVEX OUTER SIDES OF SAID VALVE ELEMENT BEING POSITIONED WITHIN SAID CUPSHAPED MEMBER AND ADAPTED TO NORMALLY ENGAGE SAID VALVE SEAT TO CLOSE SAID FLUID OPENING, AND (D) A COMPRESSION SPRING URGING SAID VALVE ELEMENT INTO YIELDING ENGAGEMENT WITH THE SAID VALVE SEAT TO CLOSE SAID FLUID OPENING AND EXTENDING INTERIORLY IN SAID CUP-SHAPED ELEMENT BETWEEN SAID INTURNED FLANGE AND THE CONCAVE INTERIOR REGION OF SAID VALVE ELEMENT BEYOND THE PLANE OF THE SEATING ENGAGEMENT OF SAID VALVE ELEMENT WITH SAID VALVE SEAT IN SAID FLUID PASSAGE, SAID SPHERICALLY CURVED CONVEX SURFACE BEING ARRANGED TO ENGAGE SAID VALVE SEAT IN PREDETERMINED ANGULAR DISPLACEMENTS OF SAID VALVE ELEMENT RELATIVE TO SAID SEAT AND TO PROJECT SUFFICIENTLY INTO SAID OPENING SUCH THAT THE PROJECTION REMAINS LOCATED IN THE OPENING IN ALL OPERATING POSITIONS OF THE VALVE.