Today in 2000, US Patent 6112932 A was issued, an invention of Ronald E. Holdren, for his “Beverage Can With Flow Enhancing Sidewall Structure.” Here’s the Abstract:

A beverage container with flow enhancing sidewall structure. The container is preferably provided in thin-walled aluminum for containment of carbonated or other beverages such as beer or carbonated soda. The container has a liquid outlet, and adjacent the liquid outlet, but in the substantially cylindrical sidewalls, a generally nose-shaped inwardly indented liquid flow enhancing structure is provided. The flow enhancing structure is provided with a generally reducing cross-sectional area when progressively examined in transverse cross-sectional area toward the liquid outlet end of the cylindrical sidewall. The generally nose-shaped structure may be offset from the centerline of the liquid outlet to further enhance liquid outflow. Although in a preferred embodiment the nose-shaped structure is substantially pyramidal in shape, the structure may alternately be provided as a section of an oblique circular cone, or other flow enhancing shape. Use of such a structure enables a user to locate the container outlet by use of tactile sense alone, such as by use of a thumb. Also, because the flow enhancing structure is inwardly indented, the beverage can is rollable for easy handling during manufacture and distribution.