Bottle closure

Claim 1

A closure for a receptacle having an a first external bead in the vicinity of the mouth thereof and a second external bead lower than the first bead, comprising a one-piece closure construction having: a hollow flexible annular insert of flexible thermoset material integral with the base and of at least equivalent flexibility depending from the base insertable within the receptacle and adapted to press and increasingly seal against and conform to an internal wall of the receptacle under the influence of increasing pressure within the receptacle, corrugations on said insert for pressing against the internal wall of the receptacle, hollow outer annular wall of flexible thermoset synthetic material, shorter than said insert, integral with the base and surrounding the insert and depending from the base for substantially surrounding and covering the first bead on the receptacle and adapted to press and increasingly seal against the bead under the influence of increasing pressure within the receptacle, means formed integrally with the base for relieving fluid pressures within the receptacle above a predetermined level comprising a thinned portion of the base over the mouth of the receptacle of a geometry and thickness adapted to burst at a level of fluid pressure above a predetermined level of sealing pressure within the receptacle, severable skirt means extending from the hollow outer annular wall and adapted to engage the second external bead tightly, said skirt means having flexibility and stretch characteristics which facilitate advancing the skirt axially over the second external bead without tearing the skirt means, the outer annular wall or the skirt means from the outer annular wall, said skirt means further having annular shoulder means extending laterally beyond the hollow outer annular wall for receiving plunger means for urging the closure over the receptacle and axially over the first external bead and into mating fit on the first external bead and for urging the skirt into engagement with the second external bead, the length of the outer annular wall and the skirt means being such that it is necessary to stretch the skirt means in the axial direction of the receptable to engage the second external bead.