Today in 1997, US Patent 5645190 A was issued, an invention of Norton Robert Goldberg, for his “Aluminum Beverage Can.” Here’s the Abstract:

An aluminum beverage can the top wall of which, and preferably the bottom wall as well, are substantially in the form of (1) a regular polygon of at least four sides, (2) a Reuleaux triangle, (3) an extended Reuleaux triangle, (4) a symmetrical curve of constant width derived from a regular polygon having an odd number of sides at least five in number, or (5) an extended symmetrical curve of constant width derived in the same way.