Knob construction

Claim 1

A DOOR KNOB ASSEMBLY INCLUDING A SHANK PORTION AND A GRIPPING PORTION COMPRISING A HOLLOW SHELL OF PLASTIC MATERIAL SET TO RIGIDITY FOR LOADS ENCOUNTERED IN DOOR KNOB OPERATION, HAVING AN OPEN OUTER END, AN ANNULAR GROOVE FORMED IN THE INNER CIRCUMFRENCE OF SAID SHELL ADJACENT SAID OPEN END, SAID GROOVE INCLUDING AN ANNULAR SLOPED CAM SHOULDER HAVING RADIAL AND AXIAL SLOPE COMPONENTS AND AN INWARDLY EXTENDING RETAINING LEDGE IN SPACED RELATION TO SAID SHOULDER, A CONCAVOCONVEX END CAP MEMBER OF RESILIENT PLASTIC HAVING A CIRCULAR PERIPHERAL PORTION SEATED IN SAID GROOVE, THE CONVEX PORTION OF SAID CAP MEMBER BEING DIRECTED TOWARD SAID SHANK PORTION, THE DIAMETER OF SAID CAP MEMBER IN THE UNSTRESSED CONDITION THEREOF BEING GREATER THAN THE DIAMETER OF SAID GROOVE, WHEREBY SAID CAP MEMBER IN THE INSERTED POSITION OF THE LATTER WITHIN SAID GROOVE IS MAINTAINED IN STRESSED CONDITION AND ASSUMES AN INCREASED CONCAVO-CONVEX POSTURE WITH RESPECT TO THE UNSTRESSED CONDITION THEREOF, SAID PERIPHERY OF SAID STRESSED CAP BEING BIASED RADIALLY AGAINST SAID CAP SHOULDER AND COACTING THEREWITH TO URGE SAID CAP MEMBER, AXIALLY AGAINST SAID LEDGE MEMBER IN STRESSED CONTACTING RELATIONSHIP.