Metso Minerals Indus., Inc. v. Johnson Crushers Intl., Inc.

When the difference between subject matter patented and prior art is such that the solution patented would have been obvious to a person skilled in the art, the patent is invalid for obviousness.

Opinion (Adelman): Johnson Crusher sued Metso Minerals claiming infringement of several claims in its ‘886 patent, relating to an improved design for a conical crusher, which crushes large rocks to produce smaller ones for use in construction projects. Metso argued that Johnson’s patent claims were invalid because they were anticipated by prior art, and moved for summary judgment. Metso introduced a device meeting the requirements of one of the claims at issue, which was on the market several years before Johnson’s patent issued. Because the court construed the claim in question to read on the preexisting device, the court invalidated that claim. The other claims in question, however, were not anticipated by that device. Accordingly, Metso argued that those claims were invalid for obviousness. Examining the device used to invalidate the first claim, the court determined that the differences between that device and the remaining questionable claims of Johnson’s patent were small and would have been obvious to a person skilled in the art. Accordingly, the court GRANTED Metso’s motion for summary judgment.