Reynolds Metals Company v. Aluminum Company of America, a Corporation, and National Can Corporation, a Corporation

BAUER, Circuit Judge.

In this civil action, the Reynolds Metals Company charged Alcoa and National Can with infringement of U.S. Patents 3,691,972 and 3,814,590. These patents — known as the “Bylund” patents — deal with the manufacture of twelve ounce aluminum cans for beer and soft drinks. The lower court awarded judgment to Reynolds, and Alcoa and National Can now appeal.

I

To understand fully the issues presented in this appeal, we must first define some key concepts in the manufacturing of aluminum cans. The process of fabricating aluminum sheet involves the casting of molten aluminum into…