Can Filing a Patent Infringement Suit Hurt You in a Re-Exam?

MARK TERRY, ESQ.

A Board of Patent Appeals and Interferences decision in Smucker v. Mack-Ray considered whether statements made in a patent-infringement complaint could be used against the patent owner during reexamination.

The patent owner had accused a commercial dispenser of infringement. During reexamination, the challenger argued that because the accused dispenser was described in an earlier reference, the infringement complaint amounted to an admission that the patent claims were anticipated by prior art.

The Board rejected that argument. A basic infringement pleading stating ownership of a patent and infringement by an accused product did not establish the legally correct construction of the patent claims or concede that the prior-art reference disclosed every limitation.

Claim construction is a matter of law. A patent owner’s litigation position does not automatically determine the broadest reasonable interpretation applied by the Patent Office, particularly where the challenger cannot identify persuasive authority or show where the prior art actually discloses the disputed limitation.

The decision is a reminder that reexamination arguments should remain focused on the claim language, the cited references, and the evidentiary record. Highly creative collateral arguments may distract from the controlling issues and can undermine credibility when they are unsupported.

Patent owners should nevertheless coordinate litigation and Patent Office strategy carefully. Pleadings, claim charts, expert positions, and statements made in one forum can be scrutinized in another, even when they are not treated as binding admissions.