Closure cap

Claim 2

A closure cap adapted to seal the neck of a container the closure cap being formed of a molding of elastomeric material and having a top portion, an annular skirt which extends from the periphery of the top portion and which has an internally threaded part which is adapted firmly to engage an externally threaded portion of the neck on being screwed onto the latter, and an annular resilient flange portion which extends from and radially inwardly of the skirt and which is spaced from the internal surface of the said top portion by an annular groove, the lowermost portion of the skirt being connected to the remainder thereof only by a plurality of angularly spaced apart bridge portions the radial thickness of each of which varies circumferentially of the closure cap, the said thickness increasing in the direction in which the closure cap is unscrewed from the container, the said lowermost portion being adapted to be snapped over but to be irremovable from an abutment on the neck of the container, the bridge portions being broken and the said lowermost portion remaining trapped on the neck whenever the closure cap is unsealed from the neck.

Claim 3

A container having a neck provided with a closure cap which is formed of a molding of elastomeric material and which is fully sEated on the neck, the closure cap having a top portion, an annular skirt which extends from the periphery of the top portion, an internally threaded portion of said skirt which is screwed onto an externally threaded portion of the said neck and which may be unscrewed therefrom, and an annular resilient flange portion which extends from and radially inwardly of the skirt and which is spaced from the internal surface of the said top portion by an annular groove whose outside diameter is less than the major internal diameter of the skirt, the resilient flange portion having a surface which is remote from the top portion and which, even when the resilient flange portion is undeformed, is radially inwardly inclined towards the top portion, the radially innermost part of the last-mentioned surface being convexly curved, the resilient flange portion being deformed by the neck and effecting a primary sealing engagement with a convexly curved radially outer edge of the end portion of the neck and a secondary sealing engagement with the top surface of the end portion of the neck, the resilient flange portion engaging the internal surface of the top portion and trapping a pocket of air therebetween, the lower most portion of the skirt being snapped over and being irremovable from an abutment on the neck of a container, the said lower most portion being connected to the remainder of the skirt only by a plurality of angularly spaced apart bridge portions, the radial thickness of each bridge portion varying circumferentially of the closure cap, the said thickness increasing in the direction in which the closure cap is unscrewed from the container.

Claim 4

A container having a neck provided with a closure cap which is formed of a molding of elastomeric material and which is fully sEated on the neck, the closure cap having a top portion, an annular skirt which extends from the periphery of the top portion, an internally threaded portion of said skirt which is screwed onto an externally threaded portion of the said neck and which may be unscrewed therefrom, and an annular resilient flange portion which extends from and radially inwardly of the skirt and which is spaced from the internal surface of the said top portion by an annular groove whose outside diameter is less than the major internal diameter of the skirt, the resilient flange portion having a surface which is remote from the top portion and which, even when the resilient flange portion is undeformed, is radially inwardly inclined towards the top portion, the radially innermost part of the last-mentioned surface being convexly curved, the resilient flange portion being deformed by the neck and effecting a primary sealing engagement with a convexly curved radially outer edge of the end portion of the neck and a secondary sealing engagement with the top surface of the end portion of the neck, the resilient flange portion engaging the internal surface of the top portion and trapping a pocket of air therebetween, the lower most portion of the skirt being snapped over and being irremovable from an abutment on the neck of a container, the said lower most portion being connected to the remainder of the skirt only by a plurality of angularly spaced apart bridge portions, the radial thickness of each bridge portion varying circumferentially of the closure cap, the said thickness increasing in the direction in which the closure cap is unscrewed from the container.

Claim 5

A container as claimed in claim 2 in which the whole of the internal surface of the top portion is flat.