Abstract: A container and closure in which the closure has an inverted U-shaped rim and a cover portion lying within the rim and joined to the inner wall of the closure rim at a position downwards from the base of the `U`. The shape and size of the container rim is such that when the closure is assembled to it, the inner wall of the closure rim is resiliently flexed inwardly about its junction with the cover portion which is thereby resiliently flexed downwards. The inner wall thus is flexed and twisted to seal against the inner surface of the container rim and applies a positive pressure to assist in sealing. In preferred constructions, the inner wall has an extension below the cover portion. The extension flexes outwards during flexing of the cover portion so as to increase the seal.

Abstract: A closure and container in which the closure has an axial flange which cooperates with the container to lock the closure in closed position, the closure also having an annular recess accommodating a resilient seal for sealing against the container rim. The seal projects from the recess before assembly of closure to container. During assembly, the container compresses the seal into the recess until in the fully closed position, the container engages a seating surface upon the closure, at which point the seal is only partially compressed.

Abstract: A snap-lid container, particularly in plastics material, of the pail type for fluid materials. A fluid-tight seal between the container and lid is effected by peripheral contact under pressure between a convex inner edge of the container lip and a splayed surface within a peripheral, inverted U-groove in the lid. Sealing pressure is provided by coaction between complementary sloping surfaces on the container lip and within the lid peripheral groove respectively which tends to draw the lid in a closing direction.