Usnr LLC v. American Wood Dryers LLC

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Usnr, LLC (Delaware)
  • Defendant: American Wood Dryers, LLC (Delaware)
  • Plaintiff’s Counsel: Schwabe, Williamson & Wyatt, P.C.
• Case Identification: 3:24-cv-00865, D. Or., 09/29/2025
• Venue Allegations: Plaintiff alleges venue is proper because Defendant resides in the judicial district and a substantial part of the events giving rise to the claims occurred within the district.
• Core Dispute: Plaintiff alleges that Defendant’s single-pass continuous lumber kilns infringe six U.S. patents related to unidirectional, multi-path lumber drying technology.
• Technical Context: The technology concerns industrial-scale ovens for drying large loads of lumber, where innovations focus on increasing energy efficiency, reducing the physical footprint, and streamlining the transport of lumber.
• Key Procedural History: The complaint alleges that Plaintiff provided Defendant with actual notice of its patent rights in or around April 2024 and requested that Defendant cease its infringing activities.

Case Timeline

Date	Event
2013-03-15	Earliest Priority Date for all Patents-in-Suit
2014-11-04	U.S. Patent No. 8,875,414 Issued
2016-11-01	U.S. Patent No. 9,482,465 Issued
2017-07-18	U.S. Patent No. 9,709,328 Issued
2019-02-12	U.S. Patent No. 10,203,156 Issued
2020-05	Accused Products featured in Timber Processing magazine
2021-04-06	U.S. Patent No. 10,969,172 Issued
2023-08-29	U.S. Patent No. 11,740,020 Issued
2024-04	Plaintiff allegedly put Defendant on notice of infringement
2025-09-29	Complaint Filed

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 9,482,465 - “Unidirectional Multi-Path Lumber Kilns,” Issued Nov. 1, 2016

The Invention Explained

• Problem Addressed: The patent addresses inefficiencies in traditional continuous lumber kilns, which often use a "counter-flow" design where lumber travels in opposite directions on parallel paths (Compl. ¶11). This approach requires a large physical footprint for the kiln and for staging raw and finished lumber at opposite ends of the structure, complicating logistics (Compl. ¶11-12; ’020 Patent, col. 3:29-39).
• The Patented Solution: The invention is a unidirectional kiln where multiple, parallel paths transport lumber in the same direction through the kiln's chambers (’465 Patent, Abstract). This design allows all raw lumber to enter at one end and all dried lumber to exit at the other, which simplifies material handling and reduces the required footprint (Compl. ¶12; ’020 Patent, col. 4:49-55). A key feature is the use of moist, heated air from a primary heated chamber to pre-heat and condition green lumber in an initial chamber, improving energy efficiency (’020 Patent, col. 8:1-10; Fig. 3A).
• Technical Importance: This unidirectional approach is alleged to permit a smaller footprint, lower construction and operating costs, and simpler, more efficient transport of lumber compared to traditional counter-flow designs (Compl. ¶12).

Key Claims at a Glance

• The complaint asserts independent claim 1 (Compl. ¶28).
• The essential elements of claim 1 of the ’465 Patent include:
  • An apparatus for drying lumber charges, comprising an elongated enclosure with a first and second chamber, and first, second, third, and fourth charge portals.
  • A first guide member defining a first flow path from the first to the third charge portal.
  • A second guide member defining a second flow path from the second to the fourth charge portal, with the flow paths extending in a first direction.
  • A first insulating member coupled with the third charge portal and configured to reduce airflow.
• The complaint does not explicitly reserve the right to assert dependent claims for this patent.

U.S. Patent No. 9,709,328 - “Unidirectional Multi-Path Lumber Kilns,” Issued Jul. 18, 2017

The Invention Explained

• Problem Addressed: This patent, part of the same family as the ’465 Patent, addresses the same technical problem of improving the efficiency and reducing the footprint of industrial lumber kilns (Compl. ¶11; ’328 Patent, col. 1:26-34).
• The Patented Solution: The patent claims a method of operating a unidirectional kiln rather than the apparatus itself. The method involves moving lumber charges along parallel flow paths in the same direction, supplying heated air to a second, primary drying chamber, and recirculating that heated air into a first, pre-heating chamber to condition the incoming lumber (’328 Patent, Abstract; col. 11:1-16). A key step is reducing airflow at the kiln's exit portals to maintain the internal thermal environment and improve efficiency (’328 Patent, col. 11:14-16).
• Technical Importance: The claimed method provides an operational framework for achieving the efficiency gains associated with the unidirectional kiln architecture (Compl. ¶12).

Key Claims at a Glance

• The complaint asserts independent claim 6 (Compl. ¶36).
• The essential elements of claim 6 of the ’328 Patent include:
  • A method of heat treating lumber in an elongated enclosure with first and second chambers and parallel flow paths.
  • Moving a first and second plurality of lumber charges along the respective flow paths in the same direction.
  • Supplying heated air to the interior of the second chamber.
  • Recirculating heated air from the second chamber across the flow paths within the first chamber.
  • Reducing airflow through the charge exit portals from the second chamber.
• The complaint does not explicitly reserve the right to assert dependent claims for this patent.

U.S. Patent No. 10,203,156 - “Unidirectional Multi-Path Lumber Kilns,” Issued Feb. 12, 2019

• Technology Synopsis: This patent claims a lumber drying system comprising an elongated enclosure with at least first and second sections, a transport system for moving lumber, and fans to circulate heated air from the second section to the first. It focuses on the system's structural and functional components, including interior baffles and selectively operable charge portals (’156 Patent, Abstract; col. 11:50-12:1).
• Asserted Claims: The complaint asserts infringement of claim 1 (Compl. ¶44).
• Accused Features: The complaint alleges that Defendant's SPC kilns embody the claimed system (Compl. ¶42).

U.S. Patent No. 11,740,020 - “Unidirectional Multi-Path Lumber Kilns,” Issued Aug. 29, 2023

• Technology Synopsis: This patent claims a method of drying lumber in a unidirectional kiln. The method involves advancing lumber charges along parallel flow paths, operating fans to circulate heated air, and organizing the lumber into batches based on characteristics that affect drying time, such as dimensions or species (’020 Patent, Abstract; col. 12:30-34).
• Asserted Claims: The complaint asserts infringement of claim 9 (Compl. ¶52).
• Accused Features: The complaint alleges Defendant's making, using, and selling of its SPC kilns infringes the claimed method (Compl. ¶50-51).

U.S. Patent No. 8,875,414 - “Unidirectional Multi-Path Lumber Kilns,” Issued Nov. 4, 2014

• Technology Synopsis: This early patent in the family claims a method of heat treating lumber using the unidirectional multi-path architecture. The method emphasizes causing a pressure differential between the chambers to drive heated, moist air from the second chamber to the first, and reducing airflow at the exit portals (’414 Patent, col. 11:49-59).
• Asserted Claims: The complaint asserts infringement of claims 1, 2, 12-17, and 19-21 (Compl. ¶58).
• Accused Features: The complaint alleges Defendant infringes by making, using, and selling its SPC kilns (Compl. ¶58).

U.S. Patent No. 10,969,172 - “Unidirectional Multi-Path Lumber Kilns,” Issued Apr. 6, 2021

• Technology Synopsis: This patent claims a method of modifying a lumber drying system. It involves operatively coupling a transport system to a multi-section kiln to advance lumber charges along parallel flow paths in a unidirectional manner (’172 Patent, col. 11:55-12:12).
• Asserted Claims: The complaint asserts infringement of claims 1 and 5-9 (Compl. ¶64).
• Accused Features: The complaint alleges Defendant infringes by practicing the patented methods in the construction or conversion of its SPC kilns (Compl. ¶4, ¶64).

III. The Accused Instrumentality

Product Identification

The accused instrumentalities are Defendant’s "single-pass, continuous kilns" ("SPC kilns") (Compl. ¶3, ¶13).

Functionality and Market Context

The complaint alleges that the accused SPC kilns are "direct copies of USNR's unidirectional kilns" (Compl. ¶13). It further alleges that these kilns are described on Defendant's "Continuous Kilns" website, depicted in a promotional video, and featured in a May 2020 article in Timber Processing magazine (Compl. ¶21). No probative visual evidence provided in complaint. Based on these allegations, the accused products are industrial-scale lumber kilns that dry multiple loads of lumber simultaneously as they travel along separate, parallel paths in the same direction through the kiln (Compl. ¶11-13).

IV. Analysis of Infringement Allegations

The complaint does not contain narrative infringement allegations or claim charts in its main body. Instead, it states that infringement of the asserted claims of each patent is detailed in Exhibits 7, 8, 9, 10, 13, and 14, which were not provided with the complaint document (Compl. ¶22, ¶28, ¶36, ¶44, ¶52, ¶58, ¶64). The core narrative theory is that Defendant's SPC kilns are "direct copies" of Plaintiff's patented technology and therefore practice the elements of the asserted apparatus, system, and method claims (Compl. ¶13).

Identified Points of Contention

• Scope Questions: A potential dispute may arise over the structural definitions in the apparatus claims. For instance, for the ’465 Patent, a question is whether the accused SPC kilns possess distinct structures that meet the claim limitations of a "first chamber" and a "second chamber," as opposed to a single, continuous enclosure with different operational zones.
• Technical Questions: For the method claims, such as claim 6 of the ’328 Patent, a key question may be whether the accused kilns, in operation, perform the specific step of "recirculating heated air received from the second chamber across the... flow paths within the first chamber." The analysis would require evidence of the specific airflow patterns and thermal dynamics within the accused products.

V. Key Claim Terms for Construction

The Term: "a first chamber" and "a second chamber" (from claim 1 of the ’465 Patent)

Context and Importance

The claimed invention is structurally defined by this multi-chamber arrangement. Infringement requires that the accused SPC kilns embody this specific structure. Practitioners may focus on whether the accused kilns, which may be constructed as a single elongated building, contain internal divisions or functional distinctions sufficient to meet the definition of two separate chambers.

Intrinsic Evidence for Interpretation

• Evidence for a Broader Interpretation: The specification suggests the chambers may be adjoined sections of a larger structure, stating a kiln "may include a first chamber 110 coupled to a second chamber 120 to form an elongated enclosure" (’020 Patent, col. 4:13-15). This could support an interpretation where functional zones within a single structure constitute separate "chambers."
• Evidence for a Narrower Interpretation: The specification often describes the chambers with distinct functions, where the first is an unheated pre-heating/conditioning zone and the second is a heated drying zone (’020 Patent, col. 3:58-63). This may support a narrower construction requiring distinct structural and functional characteristics for each claimed "chamber."

The Term: "insulating member configured to reduce airflow" (from claim 1 of the ’465 Patent)

Context and Importance

This limitation requires a specific functional component at the kiln's exit portal. The dispute will likely center on what type of structure qualifies and what degree of "airflow reduction" is required.

Intrinsic Evidence for Interpretation

• Evidence for a Broader Interpretation: The specification discloses flexible options, including "a polymer curtain, a vertical strip curtain, or swinging doors," suggesting the term is not limited to a perfect seal (’020 Patent, col. 8:15-19).
• Evidence for a Narrower Interpretation: Other embodiments describe a more robust, actively controlled component, such as a "door that [is] selectively actuable to open as a lumber charge reaches the distal end" (’020 Patent, col. 6:65-67). This could be used to argue for a construction requiring more than a simple passive curtain.

VI. Other Allegations

Indirect Infringement

The complaint alleges that Defendant induces its customers to infringe the patented methods and contributes to infringement (Compl. ¶27, ¶35, ¶43, ¶51). It also alleges that Defendant practices the methods during the "construction of such kilns or their conversion" (Compl. ¶4).

Willful Infringement

Willfulness is alleged for all asserted patents, based on Defendant's alleged "full knowledge" of the patents and Plaintiff's rights (Compl. ¶29, ¶37, ¶45, ¶53, ¶59, ¶65). This allegation is supported by the claim that Plaintiff provided Defendant with actual notice of infringement in April 2024, after which the allegedly infringing activities continued (Compl. ¶24).

VII. Analyst’s Conclusion: Key Questions for the Case

• A core issue will be one of structural mapping: Does the physical construction of Defendant's "single-pass, continuous kilns" meet the specific multi-chamber architecture and component limitations (e.g., "first chamber," "second chamber," "insulating member") recited in the asserted apparatus claims, or is there a fundamental structural difference?
• A key evidentiary question will be one of process verification: For the asserted method claims, what evidence demonstrates that the accused kilns, when operated by Defendant or its customers, execute all the claimed steps, particularly the specific thermal feedback loop of "recirculating heated air" from the primary drying chamber to the pre-heating chamber?
• A central question for damages will be one of scienter: Did Defendant's alleged infringement become willful after it received actual notice of Plaintiff's patent rights in April 2024, potentially exposing Defendant to enhanced damages for any subsequent infringement?