Muncie Gear Works, Inc. v. Outboard, Marine & Manufacturing Co.

Background

This dispute involved an inventor, the company that owned his patent, and the company that held the exclusive license, against manufacturers and sellers accused of copying outboard motors. The patent covered an anti-cavitation plate and a smooth-walled lower housing used to prevent propeller air-drawing (“cavitation”). The inventor filed an application in August 1926; later amendments in December 1928 and March 1929 changed the claimed features. Witnesses for the patent owners testified that motors with the claimed features were marketed in 1926 and copied by competitors in 1927. Lower courts split: the trial court found the claims invalid as mere aggregation, while the appeals court held the claims valid and infringed.

Reasoning

The Court focused on a law that bars patents when an invention was publicly used or sold more than two years before it was first presented to the Patent Office. The Court found the patent owner’s own witnesses admitted that devices embodying the claimed invention were in public use or on sale in 1926, more than two years before the specific claims were first presented in the Patent Office. The Court also concluded the early application and the December 1928 amendments did not disclose the exact invention later claimed. On that basis the Court held the challenged claims invalid under the two-year rule and reversed the judgment below.

Real world impact

The decision voids the specific patent claims at issue, freeing competing manufacturers and sellers from those infringement claims. It removes a patent-based monopoly over a sizable industry segment referenced in the record. The Court declined to decide other legal questions about the patent, so other issues could be raised later.