Patent ID: 7665637

Claim:
A closure suitable for mounting onto a container, the container having an end portion defining a container opening, the closure comprising: a main closure having: a top portion having an aperture therethrough; a skirt portion depending downwardly from the top portion that is attachable to the container end portion; a main closure sealing rib that, on attachment of the main closure to a container, forms a seal with the end portion of the container; a spout extending upwardly from the top portion, the spout defining a bore that is in fluid communication with the aperture in the top portion, an outer surface of the spout having a plurality of outwardly extending protuberances thereon; and a plug member having a radially outer surface and mounted to the spout; and a top cap mounted to the spout, the top cap having an upper portion that has an inner surface defining an opening through the upper portion, the opening being in fluid communication with the bore of the spout, a substantially cylindrical skirt portion depending downwardly from the upper portion, and a top cap sealing member extending inwardly from an inside surface of the top cap; the top cap being relatively movable between a first position where the plug member is at least partially within the opening and the top cap sealing member forms a seal with the outer surface of the spout and at least a second position where the plug member is withdrawn from the opening; and wherein on relative movement of the top cap from said first position towards said second position, the top cap sealing member rides up over said protuberances so as to at least partially release the seal made by the top cap sealing member with said spout; and further wherein the top cap sealing member comprises an annular sealing rib that on mounting of the top cap to the spout in said first position seals with the outer surface of the spout below the protuberances thereon, the annular sealing rib including a first portion which is contiguous with an inner surface of the skirt portion of the top cap and at least a second portion contiguous with the first portion, the second portion, prior to mounting of the top cap to the spout, extending radially inwardly to a circular free edge.