Container with expansion type locking closure

Claim 1

In combination, (1) a container made of flexible, resilient material having a circular top opening, a finish portion extending upwardly and inwardly from the body of the container in the form of the frustum of a cone which terminates at the top in an integral, outwardly extending, annular flange having a top surface upwardly and forming a circular container lip, and wherein the confluence of said frustum and said lip defines said opening (2) a lid made of flexible, resilient material having a central circular closing portion conforming generally to said circular top opening but smaller in diameter than said opening and an elevated, inverted generally U-shaped circular rim having (i) an interior surface opposing said upwardly facing surface of said circular container lip and conforming in shape to said surface of said circular lip but being slightly wider (ii) an outer annular peripheral skirt having an outer wall and an inner wall (iii) an inner annular skirt having an outer wall and an inner wall, wherein the bottom periphery of the inner wall of said outer skirt is slightly larger in diameter than the diameter of the outwardly facing outer periphery of said circular lip and (3) an expanding pressure ring which is circular when in operative, extended position and is below the plane of said circular top opening, said pressure ring when in operative position pressing radially outwardly against the bottom portion of said outer wall of the inner annular skirt of said lid, thus (a) extending the diameter of the bottom portion of said inner skirt, so that the outer diameter of the lid in the plane of the ring is larger than the diameter of the top of said frustum, and thus locking the lid and (b) pulling said outer skirt into firm contact with the outwardly facing outer periphery of said circular lip, and pulling said opposing interior surface into contact with the upwardly facing surface, of said lip, thereby forming a seal with said container finish.