Seymour’s Shadow: Reviving the Supreme Court’s Standard for Prior Art Enablement

by Dennis Crouch

Pending Supreme Court petition in Converter Manufacturing v. Tekni-Plex (No. 24-866), focuses on the question of who bears the burden of proving whether prior art references enable the claimed invention, and what standard should apply. As far as I can discern, the Federal Circuit's basic approach stems from ex parte patent appeals and has three key elements:

1. In order to be anticipating, the prior art must enable the claimed invention; and
2. The party challenging the patent claim has the ultimate burden of proving enablement; BUT
3. The "proof" is made so much easier by a quite strong presumption that prior art patents and printed publications are enabling.

The court's approach effectively shifts the burden to the patentee to prove non-enablement.  But, it is clear from all the old patent cases that the patent challenger has the burden, not the patentee (particularly once the patent issues). The key case on point here is Seymour v. Osborne, 78 U.S. 516 (1870) along with subsequent Supreme Court precedent in the late 1800s.