PTAB challenges

Proceedings overview

One active AIA trial proceeding, IPR2025-01116, is on file for US Patent 11261566. This proceeding is currently in the trial phase, meaning institution was granted, but a Final Written Decision has not yet been issued. For a defendant, this indicates that the patent's claims are actively being challenged, and their validity is currently undetermined by the PTAB.

IPR2025-01116 — Albany International Corp. v. Voith Patent GmbH

• Type: Inter Partes Review
• Filed: 2025-06-06
• Status: Trial Instituted. The petition was granted, and the inter partes review is currently ongoing at the PTAB.
• Judge panel: The specific panel members for this proceeding are not publicly available in the provided search results. However, under the USPTO's interim process for PTAB workload management, implemented in March 2025, the Director (currently John Squires as of October 2025) first determines discretionary considerations for institution. If institution is not discretionarily denied, a three-member panel of PTAB judges is then assigned to conduct the trial on the merits.
• Petition grounds: The Petitioner, Albany International Corp., has challenged claims of US11261566 based on invalidity grounds. Discussions within the Patent Owner's Preliminary Sur-Reply indicate that "two out of the three invalidity grounds asserted in the Petition rely on limited data extracted from low-quality photographs and on measurements and calculations that are mathematically and statistically unsound." The prior art references "Adanur and Rydin" are mentioned in connection with these grounds. These invalidity grounds are typically based on 35 U.S.C. §§ 102 (novelty) and/or 103 (obviousness), which are the statutory bases for Inter Partes Review. The precise claims challenged are not explicitly detailed in the provided information.
• Institution decision: The proceeding was instituted. The exact date of the institution decision is not specified in the provided data. However, the filing date of the petition (2025-06-06) and the ongoing "Trial Instituted" status confirm that the PTAB found a reasonable likelihood that at least one challenged claim is unpatentable, thus proceeding to trial.
• Final Written Decision (if issued): Not yet issued, as the trial is ongoing.
• Settlement / termination: Not indicated.
• Appeal: Not applicable yet, as a Final Written Decision has not been issued.
• Defensive value: This active proceeding indicates that the validity of at least some claims of US11261566 is currently under scrutiny at the PTAB. A defendant facing assertion of this patent should closely monitor the IPR, as an unfavorable outcome for the Patent Owner could lead to claim cancellation, weakening the patent. Conversely, if the Patent Owner prevails, the patent's claims would be strengthened against similar prior art challenges.

Strategic summary

Currently, one Inter Partes Review (IPR2025-01116) is active against US Patent 11261566. As this proceeding is still in the trial phase, no claims of US11261566 have been canceled or definitively sustained by the PTAB. All claims of the patent remain valid and enforceable until a Final Written Decision is issued. The Petitioner, Albany International Corp., is challenging claims based on invalidity arguments, likely under 35 U.S.C. §§ 102 and/or 103, using prior art references such as "Adanur and Rydin." The Patent Owner, Voith Patent GmbH, is actively defending the patent, arguing against the Petitioner's methodology for assessing prior art.

The estoppel landscape for this patent is developing. If IPR2025-01116 results in a Final Written Decision (FWD), the Petitioner and its privies would be estopped from raising any ground that was raised or reasonably could have been raised in the IPR in future district court or ITC proceedings. For a defendant not privy to Albany International Corp., prior-art grounds not addressed in this IPR (or those that could not have been raised in an IPR, such as public use or on-sale bar defenses) would still be available. The USPTO introduced new rules in October 2025 proposing that petitioners agree not to pursue invalidity challenges under §§ 102 or 103 in other forums if an IPR is instituted. It is unclear if such a stipulation was made by Albany International Corp. for IPR2025-01116.

This is the only PTAB proceeding identified for US11261566, suggesting a singular challenge at this time. The fact that an IPR was instituted, despite the Director's increasingly restrictive approach to institution in 2025, indicates the PTAB found the merits of the petition to be sufficient to proceed to trial.

Recommended next steps

• Monitor IPR2025-01116 closely: As the proceeding is "Trial Instituted," the next key milestones will be the oral hearing (if scheduled) and the Final Written Decision (FWD). The PTAB has a statutory deadline of one year from the institution date to issue a FWD. Given the filing date of 2025-06-06, and assuming an institution date around late 2025, the FWD for IPR2025-01116 would likely be due in late 2026. This decision will determine the patentability of the challenged claims.
• Review the institution decision: Once publicly available, carefully examine the PTAB's institution decision for IPR2025-01116 to understand the specific claims challenged and the Board's reasoning for instituting trial. This will provide insight into the perceived weaknesses of the patent claims.
• Analyze the petition and Patent Owner Response: If available, reviewing the full petition and the Patent Owner's Preliminary Response and Sur-Reply would provide detailed arguments on claim construction, prior art, and patentability, which could inform a defendant's own invalidity contentions. The Patent Owner's Preliminary Sur-Reply is already an indication of the arguments being made, particularly regarding the Petitioner's use of photographic evidence for measurements.