Background
Hongjia Wang owns U.S. Patent No. 11,007,583, which concerns a twist drill with composite cutting-blade groups “formed sequentially and spirally” on the drill’s cone portion. Viking Drill & Tool challenged the patent in two inter partes review proceedings, and the Patent Trial and Appeal Board found every challenged claim unpatentable on multiple grounds.
One ground relied on Wang’s earlier published application, known as Wang ’808, together with Gentry and/or Dufree. Wang argued that the ’583 patent was entitled to the earlier application’s filing date, which would prevent Wang ’808 from qualifying as prior art. The parties agreed that “formed spirally” required axial relief, meaning that the cutting blades were slanted rather than perpendicular to the drill bit’s rotational axis. The Board found that Wang ’808 did not expressly or inherently disclose that feature and therefore did not provide the written-description support necessary for the asserted priority claim.
The Court’s Holding
The Federal Circuit affirmed. It held that the Board applied the correct written-description standard by considering what the earlier application reasonably conveyed to a person of ordinary skill in the art. Even if axial relief was conventional or widely used, that did not supply written-description support absent an express or inherent disclosure, and Wang identified no evidence establishing that axial relief was necessarily present in the earlier application.
Substantial evidence supported the Board’s finding that Wang ’808’s reference to “connecting lines of the flutes” did not disclose axial relief. The court also held that Wang forfeited his challenges to the Board’s reliance on Viking’s expert and his argument that radial relief could satisfy “formed spirally” because he had not properly raised those issues before the Board. Because the affirmed ground rendered every challenged claim obvious, the court did not address the Board’s other invalidity grounds.
Key Takeaways
- An earlier application supports a priority claim only when it expressly or inherently discloses every limitation of the later claims.
- A feature’s allegedly conventional or obvious character cannot substitute for its disclosure in the priority application.
- Arguments concerning expert qualifications or alternative claim constructions may be forfeited if they are not properly presented to the Board.
Why It Matters
The nonprecedential decision underscores the risk of adding a claim limitation in a continuation-in-part without clear support in the earlier application. If the earlier disclosure does not establish possession of the later-claimed feature, the patent may lose the asserted priority date and the applicant’s own earlier publication may become prior art.
The ruling also highlights the importance of preserving arguments during inter partes review. Parties generally cannot wait until appeal to challenge an expert’s qualifications or advance a materially different construction of a disputed claim term.