Nachman Spring-Filled Corp. v. Kay Mfg. Co‪.‬

Defendant, in its brief on appeal, argues that, if the patent is invalid, the agreement is void as in restraint of trade, and that therefore we must inquire into the validity of the patent. This contention was not made in the court below; but we do not reject in on that account, since Muncie Gear Co. v. Outboard Co., 315 U.S. 759. 766, 768, 62 S. Ct. 865, 870, 86 L. Ed. 1171, seems to us to hold that regard for "the public interest sought to be safeguarded by the patent statutes, and so frequently present but so seldom adequately represented in patent litigation" requires that an upper court should consider important defenses in such litigation even though not raised in the court below.