Plastic closure with improved seal

Claim 1

A plastic closure for a bottle and the like having an externally threaded neck, said closure having a top wall, an internally threaded sidewall, and a seal, said seal comprising outer and inner concentric sealing members extending downwardly from an inner surface of said top wall, said outer sealing member extending downwardly farther than said inner sealing member and being substantially thicker than said inner sealing member, said outer sealing member having an outer side surface that extends downwardly and inwardly and having an inner side surface that extends downwardly and outwardly, said inner sealing member having outer and inner side surfaces that extend downwardly and inwardly, said inner side surface of said outer sealing member being disposed to engage an outer corner of the rim of the neck of the bottle when the closure is threaded onto the bottle, and said inner sealing member being disposed to engage the top of the rim after engagement of said corner with said inner surface of said outer sealing member, said outer sealing member being adapted to deflect outward slightly due to the engagement of its inner side surface with said corner of the rim and being substantially more rigid than said inner sealing member, said inner sealing member being adapted to deflect upwardly and inwardly to form a top seal on said rim, movement of said top wall of said closure toward said rim being limited so that when said closure is fully threaded onto said bottle, the inner surface of the inner sealing member is spaced from the inner surface of the top wall of the closure.