Containers and closures therefor

Claim 1

A container and closure assembly comprising a closure provided with a container closure portion surrounded by an annular rim portion, the rim portion including a downwardly depending annular flange and the container comprising a side wall terminating at its upper end in a rim, the closure being closed upon the container rim and the rim and rim portion having mutually engaged locking means retaining the closure upon the rim, the rim and rim portion axially compressing between them a resilient seal, the resiliency of which determines normal relative closed positions of the closure and container, and the closure being moveable under downward external pressure from the normal closed position further in the closing direction relative to the container so as to increase axial compression upon the seal, the closure and container mutually comprising an axially facing surface and a surface opposing the axially facing surface, the axially facing surface having a plurality of circumferentially spaced-apart ribs projecting axially therefrom and towards the opposing surface, the ribs being spaced from the opposing surface in the normal closed position of container and closure, movement of the closure in the closing direction causing the ribs and the opposing surface to engage one another to terminate said movement with gaps being formed between the axially facing and opposing surfaces at positions between the ribs into which a prizing tool may be inserted for removal of the closure from the container.