US Patent 9139325 Self righting container

A self righting fluid container having a flanged neck portion, a weighted base portion and an intermediate tapered section connecting the neck portion to the base portion. The center of gravity of the container, whether filled or empty, is along the centerline of the container on the positive side of a critical line which line extends normal to the horizontal plane of the support surface on which the container rests from a point where the container contacts the support surface and where the base portion intersects the tapered section.