In Victaulic Company v. ASC Engineered Sols., LLC, the District of Delaware ruled on summary judgment that ASC is estopped from asserting two obviousness grounds against a patent claim because it raised the same grounds in inter partes reexamination proceedings. At issue was whether pre-America Invents Act (AIA) reexamination estoppel under 35 U.S.C. § 315(c) applies even if the patent owner raises a different claim construction in district court than the USPTO applied during reexamination. The District Court answered “yes,” reasoning that a “party’s proposed construction of a term does not change . . . whether a party previously asserted that a claim … was obvious in an inter partes reexamination.”

D. Del.: Plaintiff’s Seeking Broader Construction in District Court Rather Than in Reexamination Does Not Preclude Reexamination Estoppel
February 6, 2023

Victaulic owns U.S. Patent No. 7,712,796 (“the ʼ796 Patent”), which relates to a “deformable mechanical pipe coupling.” Independent claims 1, 21, 41 and 44 of the ʼ796 Patent each includes a “being deformable” limitation, which recites “said segments being deformable upon adjustable tightening of said connection members so as to substantially conform the curvature of said arcuate surfaces to the outer surfaces of said pipe elements within said circumferential grooves.”
In 2012, ASC requested inter partes reexamination of certain claims of the ʼ796 Patent, including claims 1, 21, 41 and 44. ASC’s request asserted obviousness grounds against those claims based on “Reynolds” and “Reynolds in view of Webb.” The USPTO instituted reexamination on both of those grounds but determined that the claims were “valid and patentable” in a final decision.
Notably, during reexamination, the USPTO agreed to add language to the “being deformable” limitation in claims 21, 41 and 44—but not in claim 1. However, the USPTO “mistakenly omitted” the added language from its decision, and the claims were not formally amended to add that language.
In 2020, Victaulic asserted claim 1 of the ʼ796 Patent against ASC in the District of Delaware, among other claims. In its invalidity contentions for claim 1, ASC again asserted “Reynolds” and “Reynolds in view of Webb.”
In a motion for summary judgment, Victaulic argued that ASC was estopped from asserting “Reynolds” or “Reynolds in view of Webb” against claim 1 under 35 U.S.C. § 315(c) because ASC raised those grounds in the reexamination proceedings. Section 315(c) states that a “third-party requester” like ASC is “estopped from asserting at a later time, in any civil action . . . the invalidity of any claim finally determined to be valid and patentable on any ground which the [] requester raised or could have raised during the inter partes reexamination proceedings.”
In response, ASC argued that its Reynolds and Webb-based obviousness grounds were not “raised” and “could not have been raised” in the reexamination proceedings because the two proceedings involve different claim interpretations of the “being deformable” limitation in claim 1. Specifically, ASC argued that, during reexamination, the USPTO applied a narrow interpretation of “being deformable” in claim 1 that necessarily included the additional language that was supposed to be added to claims 21, 41 and 41. Thus, according to ASC, estoppel should not apply because “Victaulic now asserts an interpretation of the [‘being deformable’] claim limitation . . . in claim 1 that is broader than the Board’s interpretation of the claim,” which presents new “issues” when asserting Reynolds and Webb in district court.
The District Court rejected ASC’s argument, ruled that estoppel applied, and granted summary judgment in favor of Victaulic. In coming to its conclusion, the District Court determined that “raised or could have raised” in § 315(c) refers to whether the same claims are at issue, not the same interpretations, citing In re Affinity Labs of Texas, LLC, 856 F.3d 883, 891-92 (Fed. Cir. 2017). When ASC requested reexamination, claim 1 “had the same language as it has now,” which “has only ‘one correct construction.’” Accordingly, even if Victaulic is applying a different construction than the USPTO, that “does not change either how the Court must construe that term or whether a party previously asserted that a claim which includes that term was obvious in an inter partes reexamination.” Accordingly, ASC was “estopped from asserting in this action that Claim 1 of the ʼ796 Patent is invalid as obvious in view of Webb and Reynolds because ASC raised or could have raised those invalidity grounds in the [reexamination].”
The District Court further noted in a footnote that “ASC could have raised its real argument—i.e., that the IPR added limitations to Claim 1” had it not “forfeited the chance to bring such a motion” (citing a sealed document).
Practice Tip: In light of estoppel provisions under pre- and post-AIA patent statutes, practitioners should proceed with caution when asserting the same prior art in district court that they asserted in prior proceedings, including reexaminations, before the USPTO. As shown in Victaulic, the Patent Act’s estoppel provisions are “severe” and may apply even if claims are interpreted or construed differently between the proceedings.
Victaulic Company v. ASC Engineered Sols., LLC., Civil Action No. 20-887-GBW (D. Del. Nov. 30, 2022).
Victaulic owns U.S. Patent No. 7,712,796 (“the ʼ796 Patent”), which relates to a “deformable mechanical pipe coupling.” Independent claims 1, 21, 41 and 44 of the ʼ796 Patent each includes a “being deformable” limitation, which recites “said segments being deformable upon adjustable tightening of said connection members so as to substantially conform the curvature of said arcuate surfaces to the outer surfaces of said pipe elements within said circumferential grooves.”
In 2012, ASC requested inter partes reexamination of certain claims of the ʼ796 Patent, including claims 1, 21, 41 and 44. ASC’s request asserted obviousness grounds against those claims based on “Reynolds” and “Reynolds in view of Webb.” The USPTO instituted reexamination on both of those grounds but determined that the claims were “valid and patentable” in a final decision.
Notably, during reexamination, the USPTO agreed to add language to the “being deformable” limitation in claims 21, 41 and 44—but not in claim 1. However, the USPTO “mistakenly omitted” the added language from its decision, and the claims were not formally amended to add that language.
In 2020, Victaulic asserted claim 1 of the ʼ796 Patent against ASC in the District of Delaware, among other claims. In its invalidity contentions for claim 1, ASC again asserted “Reynolds” and “Reynolds in view of Webb.”
In a motion for summary judgment, Victaulic argued that ASC was estopped from asserting “Reynolds” or “Reynolds in view of Webb” against claim 1 under 35 U.S.C. § 315(c) because ASC raised those grounds in the reexamination proceedings. Section 315(c) states that a “third-party requester” like ASC is “estopped from asserting at a later time, in any civil action . . . the invalidity of any claim finally determined to be valid and patentable on any ground which the [] requester raised or could have raised during the inter partes reexamination proceedings.”
In response, ASC argued that its Reynolds and Webb-based obviousness grounds were not “raised” and “could not have been raised” in the reexamination proceedings because the two proceedings involve different claim interpretations of the “being deformable” limitation in claim 1. Specifically, ASC argued that, during reexamination, the USPTO applied a narrow interpretation of “being deformable” in claim 1 that necessarily included the additional language that was supposed to be added to claims 21, 41 and 41. Thus, according to ASC, estoppel should not apply because “Victaulic now asserts an interpretation of the [‘being deformable’] claim limitation . . . in claim 1 that is broader than the Board’s interpretation of the claim,” which presents new “issues” when asserting Reynolds and Webb in district court.
The District Court rejected ASC’s argument, ruled that estoppel applied, and granted summary judgment in favor of Victaulic. In coming to its conclusion, the District Court determined that “raised or could have raised” in § 315(c) refers to whether the same claims are at issue, not the same interpretations, citing In re Affinity Labs of Texas, LLC, 856 F.3d 883, 891-92 (Fed. Cir. 2017). When ASC requested reexamination, claim 1 “had the same language as it has now,” which “has only ‘one correct construction.’” Accordingly, even if Victaulic is applying a different construction than the USPTO, that “does not change either how the Court must construe that term or whether a party previously asserted that a claim which includes that term was obvious in an inter partes reexamination.” Accordingly, ASC was “estopped from asserting in this action that Claim 1 of the ʼ796 Patent is invalid as obvious in view of Webb and Reynolds because ASC raised or could have raised those invalidity grounds in the [reexamination].”
The District Court further noted in a footnote that “ASC could have raised its real argument—i.e., that the IPR added limitations to Claim 1” had it not “forfeited the chance to bring such a motion” (citing a sealed document).
Practice Tip: In light of estoppel provisions under pre- and post-AIA patent statutes, practitioners should proceed with caution when asserting the same prior art in district court that they asserted in prior proceedings, including reexaminations, before the USPTO. As shown in Victaulic, the Patent Act’s estoppel provisions are “severe” and may apply even if claims are interpreted or construed differently between the proceedings.
Victaulic Company v. ASC Engineered Sols., LLC., Civil Action No. 20-887-GBW (D. Del. Nov. 30, 2022).
Previous Entries
IP Newsflash
July 13, 2026
In a precedential and sua sponte Director Review decision, USPTO Director Squires recently vacated three related institution decisions nearly six months after institution where a district court later found the challenged claims invalid. Because the fourteen-day deadline to request Director Review of the institution decisions had passed, the Director used this opportunity to formally extend the deadline in two ways. First, he extended the fourteen-day deadline under 37 C.F.R. § 42.75(c)(1) to thirty days, which “puts requests for Director Review of decisions to institute trial on equal footing to requests for Director Review of final decisions or decisions not to institute trial.” Second, he outlined certain “exceptional circumstances” that warrant a further extension of the deadline to account for changes in the case that “surface after the deadline.” In the case at hand, the Director found the district court’s invalidity finding to be such an “exceptional circumstance” and ultimately initiated review and vacated the institution decisions on that basis.
IP Newsflash
June 5, 2026
The Supreme Court unanimously held that for a complaint of induced infringement, a patent owner must allege that the accused infringer took affirmative, not passive, steps to encourage direct infringement. Thus, where a generic drug has a skinny label, to induce infringement of the carved-out patented use of the drug, the generic company must have taken steps that were designed to cause others to perform the patented use, not just steps that could cause such conduct.
IP Newsflash
May 07, 2026
The Northern District of Illinois granted a summary judgment motion of no invalidity based on indefiniteness because the qualitative terms like “sufficiently slow” and “desired period of time” were definite when viewed in light of the surrounding claim language and specification.
IP Newsflash
April 9, 2026
In the April 1, 2026 edition of the Official Gazette, the U.S. Patent and Trademark Office announced a new procedural framework that permits patent owners to submit a limited, early response to a request for ex parte reexamination.