Wayne K. Pfaff v. Wells Electronics, Inc.
Decided November 10, 1998. John Paul Stevens delivered the opinion of the Court.
Docket 97-1130 · 525 U.S. 55 (1998) · Cited 353 times
Holding
Pfaff ’s patent is invalid because the invention had been on sale for more than one year in this country before he filed his patent application.
The Court’s statement of the holding, from the opinion’s syllabus. The syllabus is prepared by the Reporter of Decisions and is not part of the opinion of the Court — read the official opinion for authority.
How the Justices voted
Decided 9–0.
Majority · 9
“Concurring” means agreeing with the outcome; any split shown is the Court’s judgment, not each Justice’s reasoning. Source: the Supreme Court Database (Spaeth et al.), Washington University.
Precedents cited
Supreme Court decisions this opinion relies on, ordered by how often it cites each. Cases in our collection link through; others are named.
- Seymour v. Osborne · 78 U.S. 516 (1871)
- Corona Cord Tire Co. v. Dovan Chemical Corp. · 276 U.S. 358 (1928)
- Bonito Boats, Inc. v. Thunder Craft Boats, Inc. · 489 U.S. 141 (1989)
- Elizabeth v. Pavement Co. · 97 U.S. 126 (1878)
- Alexander Milburn Co. v. Davis-Bournonville Co. · 270 U.S. 390 (1926)
Cited by
Later Supreme Court opinions in our collection that cite this case.
- Helsinn Healthcare S. A. v. Teva Pharmaceuticals USA, Inc. · 586 U.S. 123 (2019)
- Microsoft Corp. v. i4i Ltd. Partnership · 564 U.S. 91 (2011)
- Gunn v. Minton · 568 U.S. 251 (2013)
- Eldred v. Ashcroft · 537 U.S. 186 (2003)
- Oil States Energy Services, LLC v. Greene's Energy Group, LLC · 584 U.S. 325 (2018)
Official text
Read the official opinion (U.S. Reports, govinfo.gov)
Explore from here
John Paul Stevens’s profile · All Supreme Court opinions · The Supreme Court
Source: Supreme Court of the United States, slip opinions (1998). Citation count from the Free Law Project’s CourtListener bulk data. Data last verified 2026-07-03. Informational only; verify against the primary source before relying. Not a consumer report (FCRA).