U.S. Supreme Court
Wollensak v. Reiher, 115 U.S. 96 (1885)
Wollensak v. Reiher
Argued April 14-15, 1885
Decided May 4, 1885
115 U.S. 96
The question whether delay in applying for a reissue of a patent has been reasonable or unreasonable is a question of law for the determination of the court.
The action of the Patent Office in granting a reissue and deciding that from special circumstances shown it appeared that the applicant had not been guilty of laches in applying for it is not sufficient to explain a delay in the application which otherwise appears unreasonable and to constitute laches.
When a reissue expands the claims of the original patent, and it appears that there was a delay of two years or more in applying for it, the delay invalidates the reissue unless accounted for and shown to be reasonable.
A bill in equity which sets forth the issue of a patent and a reissue with expanded claims after a lapse of two or more years and states no sufficient explanation of the cause of the delay presents a question of laches which may be availed of as a defense upon general demurrer for want of equity.
The facts which make the case are stated in the opinion of the Court.