Expanded Metal Co. v. Bradford

Background

John F. Golding, an inventor, claimed a new method for making expanded sheet metal and sued over others’ use of the technique. Expanded metal is made by cutting and opening a sheet to form a regular mesh; earlier methods either cut then stretched or used stepped cutters to cut and form strands. Lower federal courts split on whether Golding’s claimed two-step method was a valid invention and whether defendants had infringed, producing conflicting appeals court rulings that the Supreme Court reviewed.

Reasoning

The Court considered whether a method made of mechanical operations can be patented as a process and whether Golding’s specific technique was new and workable. The Justices concluded that process patents are not limited to chemical or elemental changes and may cover mechanical methods when they produce a new and useful result. The Court found Golding’s claim described two coordinated operations that produce full diamond meshes without materially shortening the sheet and that skilled mechanics could use known machines to carry out the method. Reading the patent and record together, the Court held the patent valid and accepted that there was enough evidence of infringement to support relief in one case, reversing the Third Circuit and affirming the Sixth Circuit.

Real world impact

The decision makes clear that inventors of manufacturing processes can obtain patents for coordinated mechanical techniques, not only for chemical processes. It strengthens the ability of patent owners to enforce process patents in manufacturing, affects makers and users of expanded metal, and sends the cases back to district courts for further proceedings consistent with the Court’s ruling.