PTAB challenges

Proceedings overview

There is currently one AIA trial proceeding on file for US patent 12313320. This Inter Partes Review (IPR) is in a "Pending" status, meaning the Patent Trial and Appeal Board (PTAB) has not yet decided whether to institute a trial. Consequently, no claims have been invalidated or sustained, and the patent's defensive posture remains largely untested at the PTAB.

IPR2026-00291 — QD Oxford UK Limited et al. v. Maybell Quantum Industries Inc

• Type: Inter Partes Review
• Filed: 2026-03-16
• Status: Pending. The PTAB has not yet issued a decision on whether to institute the trial. The institution decision is expected by approximately 2026-09-16 (six months from the filing date).
• Judge panel: Not yet publicly available.
• Petition grounds: The petition challenges claims 1-6, 8, and 17-19 of US12313320. The grounds asserted by the Petitioner, QD Oxford UK Ltd and Quantum Design Intl Inc, involve prior art references such as Batey, Dain, and Garside. Specifically, the petition asserts a combination of Batey's dilution refrigerator with Dain's rectangular chamber to achieve a more compact configuration and easier access, teaching a simple substitution of known chamber shapes for predictable benefits of space efficiency and serviceability. Additionally, the petition references Garside, which teaches a cryogen-free dilution refrigerator with a planar outer vacuum vessel containing an aperture providing access to an internal "working region" (experimental volume), and also discloses removable radiation shields, a gate valve for a hermetic opening, and a vacuum chamber constructed from multiple sections.
• Institution decision: Not yet issued.
• Final Written Decision: Not applicable; the proceeding is pending.
• Settlement / termination: Not applicable; the proceeding is pending.
• Appeal: Not applicable; the proceeding is pending.
• Defensive value: This proceeding is in its early stages. All challenged claims (1-6, 8, and 17-19) are currently subject to potential invalidation, but the patent owner, Maybell Quantum Industries, Inc., has the opportunity to defend them. The outcome of the institution decision will significantly influence the future defensive value, as institution would indicate the petitioner has shown a reasonable likelihood of prevailing on at least one challenged claim.

Strategic summary

As of May 29, 2026, US patent 12313320 has one active Inter Partes Review, IPR2026-00291. Claims 1-6, 8, and 17-19 are currently being challenged. These claims relate to dilution refrigerators with cuboid-shaped outer vacuum chambers featuring planar surfaces and openings for access to an internal experimental volume. Since the IPR is still in the "Pending" status, no claims have been definitively canceled or sustained by the PTAB. All claims not listed as challenged (e.g., claim 7, 9-16) remain untested by this particular IPR.

The estoppel landscape is not yet established because no institution decision or final written decision has been rendered. If the PTAB institutes the IPR, and subsequently issues a Final Written Decision, § 315(e)(2) estoppel would apply to the petitioner (QD Oxford UK Limited et al.) and their privies for any ground raised or that reasonably could have been raised during the trial. For a defendant currently being asserted against, this means that if they are not privy to the petitioner, they could potentially raise the same or similar prior-art grounds if the IPR is not instituted, or different grounds if it is. There are no clear pattern signals of aggressive PTAB appeals by the patent owner or involvement of defensive aggregators like Unified Patents based on the current information.

Recommended next steps

• Monitor IPR2026-00291 closely. The critical upcoming milestone is the institution decision deadline, which is expected by approximately 2026-09-16. This decision will determine whether the PTAB proceeds to a full trial on the challenged claims.
• Review the petition for IPR2026-00291 to understand the specific prior art and arguments being made against claims 1-6, 8, and 17-19. This will provide insight into the potential weaknesses of these claims.
• If facing assertion of this patent, consider whether any asserted claims fall within the challenged set. If so, the outcome of the IPR will directly impact the strength of the patent owner's infringement arguments for those claims. If not, the remaining claims are currently unaddressed by this IPR.