Thermaduct v. Albers Mechanical Contractors
Thermaduct, LLC. v. Albers Mechanical Contractors, Inc. d/b/a Ducts and Cleats; and Albers Sheetmetal and Ventilating, Inc., d/b/a Ducts and Cleats
- Shannon Elkins
- 0:26-cv-00963
- U.S. District Court · District of Minnesota
- 7
In Thermaduct v. Albers Mechanical Contractors, Magistrate Judge Elkins denied Thermaduct's request to add a patent prosecution bar to a protective order governing discovery.
Parties in patent litigation who wish to restrict opposing counsel from participating in patent prosecution work during the case. Specifically relevant to patent litigants in the District of Minnesota seeking protective order provisions, and to attorneys who handle both patent litigation and patent prosecution, who may face restrictions on their work depending on whether they qualify as 'competitive decisionmakers.'
What happened
In Thermaduct, LLC v. Albers Mechanical Contractors, Inc. d/b/a Ducts and Cleats and Albers Sheetmetal and Ventilating, Inc. d/b/a Ducts and Cleats (No. 26-cv-0963), the parties are in a patent dispute over HVAC duct technology. During pretrial proceedings, Thermaduct asked the court to include a special provision in the protective order—called a 'patent prosecution bar'—that would prevent the defendants' litigation lawyers from also working on obtaining new patents for any clients in the HVAC duct technology field, out of concern that those lawyers might inadvertently use Thermaduct's confidential information to help competitors.
A patent prosecution bar is a restriction sometimes added in patent cases because lawyers who both litigate patents for a client and help obtain new patents for that client can unintentionally let an opponent's secret information influence the patent-seeking work—even when they try hard not to. Courts apply a two-part threshold test: first, whether the opposing party's litigation lawyers are 'competitive decisionmakers' actively involved in patent strategy; and second, whether sharing discovery information creates a real risk that those lawyers might inadvertently use it in a competitive way. Here, the court found that the defendants' litigation lawyers do not advise the defendants on new inventions, do not make patent strategy decisions, and do not write or approve patent applications—a separate law firm handles all of that. Thermaduct's argument that the litigation lawyers might someday take on that role was found to be too speculative.
Because Thermaduct failed to satisfy either of the two threshold requirements, Magistrate Judge Elkins denied the request for a patent prosecution bar. The court also noted, without needing to decide the point, that Thermaduct's proposed bar was overbroad because it would have restricted the defendants' lawyers from working on HVAC duct patents for any client—not just the defendants—and that losing access to chosen litigation counsel outweighed any speculative risk of harm.
The detailed version
- Thermaduct v. Albers Mechanical Contractors · No. 0:26-cv-00963
- Shannon G. Elkins
- Sept. 3, 2026
Background
This patent dispute over HVAC duct technology came before the court on a discrete discovery-management issue arising out of a pretrial conference held on August 18, 2026. The parties had negotiated a Partially Contingent Stipulation for a Protective Order (governing how confidential discovery materials are handled), but disagreed on one provision: Thermaduct's proposal to include a "patent prosecution bar" (PPB). A PPB is a designation in a protective order that forbids attorneys who receive an opponent's sensitive discovery materials from also engaging in patent prosecution—the process of applying for and obtaining patents—for their client in the same technology area, because of the risk that confidential information could contaminate that prosecution work. After the pretrial conference, the court entered a general Protective Order and directed briefing limited to the PPB question. The matter was fully briefed at dockets 61 and 62.
Legal Standard
Under Federal Rule of Civil Procedure 26(c)(1)(G), a court has broad discretion to issue a protective order when the moving party shows "good cause" to protect against annoyance, embarrassment, oppression, or undue burden—including shielding confidential research, development, or commercial information. The court relied on the Federal Circuit's decision in In re Deutsche Bank Tr. Co. Americas, 605 F.3d 1373 (Fed. Cir. 2010), and the District of Minnesota's decision in Carlson Pet Prods., Inc. v. N. States Indus., Inc., No. 17-CV-02529-PJS-KMM, 2019 WL 2991220 (D. Minn. July 9, 2019), for the four-factor test governing PPB requests:
- Whether the opposing party's litigation counsel are "competitive decisionmakers" (i.e., substantially engaged in patent prosecution strategy).
- Whether the exchange of information presents a real risk of inadvertent use by those competitive decisionmakers.
- Whether the proposed bar's duration, scope, and subject matter are reasonably tailored to the risk.
- Whether denying a party its chosen counsel outweighs the risk of inadvertent use.
The first two are threshold factors; if either is not met, the court need not reach factors three and four.
Analysis
Factor 1: Competitive Decisionmaking
The court acknowledged that Thermaduct made a satisfactory general showing that the defendants' litigation counsel (the law firm Merchant & Gould) are experienced in patent prosecution. However, the court found that Thermaduct failed to establish that those lawyers are actually acting as competitive decisionmakers for the defendants in this case. The record showed that the defendants' litigation counsel do not advise the defendants on new inventions, do not make strategic patent protection decisions, do not counsel the defendants to seek such protection, and do not write, review, or approve patent applications for the defendants—a separate firm handles all patent prosecution work for the defendants.
Thermaduct argued that the litigation counsel could engage in patent prosecution for the defendants in the future. The court rejected this as speculative, distinguishing it from Carlson, where the litigation lawyers were listed as counsel of record in patent reexamination proceedings at the USPTO, provided strategic counseling on prosecution matters, and advised their client on claim scope and strategy. None of those facts were present here.
Factor 2: Risk of Inadvertent Use by Competitive Decisionmakers
Because the defendants' litigation and patent prosecution counsel are separate firms, the court found that sensitive discovery materials accessible to litigation counsel would not be accessible to patent prosecution counsel. Thermaduct argued it was "foreseeable" that the two sets of lawyers would confer. The court disagreed, noting nothing in the record suggested such conferral had occurred or was planned, and distinguishing Cheah IP LLC v. Plaxo, Inc., No. C-08-4872 PJH (EMC), 2009 WL 1190331 (N.D. Cal. May 4, 2009), where parties did intend their litigation counsel to advise prosecution counsel freely.
Factors 3 and 4: Noted but Not Determinative
Although the court's threshold findings disposed of the motion, it noted that Thermaduct's proposed PPB was overbroad because it would bar the defendants' litigation counsel from prosecuting any HVAC duct technology patents for any client—not just the defendants. By contrast, the bar in Carlson applied only to prosecution directly for the litigation client. The court also noted that forcing the defendants' litigation counsel to choose between representing the defendants and assisting other patent prosecution clients would impose a far-reaching prohibition not warranted by the facts.
Disposition
Thermaduct's request for entry of a proposed protective order with a patent prosecution bar designation (Dkt. 57) was denied.
Read the full 7-page opinion on CourtListener, the free public archive maintained by the Free Law Project.
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