Patent ID: 7757874

Claim:
A blow-molded bottle comprising a base, a side wall having a lower margin joining the base, the side wall extending upward from the base to an upper margin, a shoulder portion extending upward from the sidewall upper margin and inward to a neck surrounding a vertical axis, the neck supporting a finish defining a opening adapted to accept a closure, the shoulder portion adjoining the neck and including a circumferentially continuous outwardly extending upper peripheral margin, an outwardly protruding ring spaced below the upper peripheral margin, and a flexible concave perimeter surface joining the upper peripheral margin to the outwardly protruding ring, the vertical midpoint of the flexible concave perimeter surface having a radius measured from the vertical axis that has an average value that is greater than (3/π) (sin π/3) (R 1 +R 2 ), where R 1 is the outermost radius of the shoulder upper peripheral margin, and R 2 is the radius of the outwardly protruding ring, and the radius varies from the average value by between one and five percent at between three and five positions around the ring perimeter.