Bottle closure and finish

Claim 1

An improved beverage bottle finish and pressure sealing closure thereof, wherein the beverage bottle finish is of the kind having a cylindrical shape with an open mouth at the upper axial end thereof, and the closure is of the type having a circular base adapted to fit over the bottle mouth, a first depending skirt fitting around the exterior surface of the finish, and means for sealing pressure in the bottle, wherein the improvement comprises: said closure being of a synthetic resin material, having a plurality of circumferentially spaced, integrally formed, fingers on the radially inner surface of the first skirt, wherein said fingers are at substantially equal axial height on the first skirt and are non-overlapping circumferentially, and wherein the pressure sealing means comprises a second skirt depending from the circular base inside the radius of the first skirt and having an outer pressure sealing face contacting said finish near the inner side of the open mouth; said finish having a like plurality of circumferentially evenly spaced indentations in the radially exterior surface thereof, each of said indentations comprising a bayonet groove having an upward opening near the plane of the bottle mouth, said finish further having a first groove portion spiraling circumferentially in a given first direction and downwardly from said opening at a first predetermined angle below the plane of the bottle mouth for guiding and retaining said fingers for movement out of the bayonet groove and through said opening during disengagement of the closure from the finish by twisting in a second and opposite direction; and the finish also having a second groove portion continuously connected to the lower end of said first groove portion and extending circumferentially and angling non-downwardly in the same direction for a sufficient distance to receive in excess of one-half of one of said fingers therein, said second groove portion having a terminal axially extending wall for preventing twisting of said finger past the position of the wall; and wherein said fingers, second skirt, and first groove portion are configured such that during disengagement of the closure from the finish said pressure sealing face ceases pressure sealing contact with the finish while said fingers are in said first groove portion and before the fingers are axially aligned with said opening.