Molded plastic closure having integral stacking support ribs and rupturable mix compartments

Claim 1

A molded plastic closure for a mixing container comprising: a base having a vertical axis of substantial symmetry when in a normal storage disposition; inner and outer spaced, substantially-parallel, circumferentially-continuous wall portions, said inner and outer wall portions being joined at the uppermost extremities thereof to define an inverted U-shaped channel to receive the rim of said container therein; the plane of said base being offset along said axis a predetermined distance below the upper extremities of said wall portions; at least one downwardly opening ingredient compartment formed contiguous with said base and extending upwardly therefrom to an upper wall; rupturable sealing means closing the bottom of said compartment; and a plurality of circumferentially spaced, substantially rigid ribs formed on said base and contiguous to the inner wall portion of said U-shaped channel and extending inwardly toward the center of said closure; said ribs extending axially at least as high as the upper wall of said compartment such that a container may be stacked thereon without collapsing said ingredient compartment along said axis.