DCT

1:25-cv-07119

Donaldson Co Inc v. Torque Parts LLC

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I. Executive Summary and Procedural Information

  • Parties & Counsel:

  • Case Identification: 1:25-cv-07119, N.D. Ill., 09/19/2025

  • Venue Allegations: Venue is based on Defendants having an established place of business in the Northern District of Illinois, including their "US Headquarters," and having committed alleged acts of infringement within the district.

  • Core Dispute: Plaintiff alleges that Defendants’ engine air filter cartridges infringe five patents related to air filter cartridge design, sealing mechanisms, and housing engagement features.

  • Technical Context: The technology concerns air filtration systems for internal combustion engines, which are critical for engine performance, efficiency, and longevity by removing particulate contaminants from intake air.

  • Key Procedural History: The complaint alleges that prior to the lawsuit, Plaintiff successfully used Amazon's APEX program to remove certain accused products from Amazon's website through assertion of the same patents-in-suit, an event which may be central to allegations of pre-suit knowledge and willful infringement.

Case Timeline

Date Event
2005-01-13 Earliest Priority Date (’820, ’119 Patents)
2006-05-10 Earliest Priority Date (’419 Patent)
2006-06-22 Earliest Priority Date (’404 Patent)
2009-12-01 ’419 Patent Issued
2011-07-05 ’404 Patent Issued
2014-01-28 ’820 Patent Issued
2014-04-29 ’119 Patent Issued
2015-03-02 Earliest Priority Date (’868 Patent)
2019-12-24 ’868 Patent Issued
2023-08-22 Amazon APEX Proceeding Initiated (’419 Patent)
2023-11-09 Amazon Listing Removed (’419 Patent)
2024-01-24 Amazon APEX Proceeding Initiated (’404 Patent)
2024-02-23 Amazon Listing Removed (’404 Patent)
2024-03-05 Amazon APEX Proceeding Initiated (’820 Patent)
2024-04-09 Amazon Listing Removed (’820 Patent)
2024-05-22 Amazon APEX Proceeding Initiated (’868 Patent)
2024-06-17 Amazon Listing Removed (’868 Patent)
2025-01-08 Amazon APEX Proceeding Initiated (’119 Patent)
2025-02-05 Amazon APEX Proceeding Initiated (’820 Patent)
2025-02-06 Amazon Listing Removed (’820 Patent)
2025-02-07 Amazon Listing Removed (’119 Patent)
2025-09-19 First Amended Complaint Filed

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

U.S. Patent No. 7,625,419 - Air filter arrangement; assembly; and, methods

  • Issued: December 1, 2009

The Invention Explained

  • Problem Addressed: The patent background section broadly states a general need for improvements in air filter arrangements for contaminant rejection (’419 Patent, col. 1:21-42).
  • The Patented Solution: The invention is an air filter cartridge with a specific three-dimensional geometry. It features a "recessed first flow face" (the inlet) and an "opposite outwardly projecting second flow face, with a central apex" (the outlet) (’419 Patent, Abstract). This V-shaped or "arrow shape" geometry on the outlet face and corresponding side pieces is designed to interface with a complementary housing, ensuring proper installation and managing airflow through the filter media (’419 Patent, col. 12:40-45; Compl. ¶29). The complaint includes a reproduction of the patent's Figure 10 to illustrate this overall shape (Compl. p. 10).
  • Technical Importance: This non-uniform shape allows for a large filter media surface area to be fitted into the constrained and irregular spaces typical of modern engine compartments.

Key Claims at a Glance

  • The complaint asserts at least independent Claim 1 and independent Claim 15 (Compl. ¶¶47, 53).
  • The essential elements of independent Claim 1 include:
    • An air filter cartridge with a media pack comprising flutes and having first and second opposite flow faces.
    • The first flow face is "recessed" and defines a recess region.
    • The second flow face projects "outwardly from the media pack and including a central apex."
    • The media pack has opposite side pieces, each of which also includes a "central apex."

U.S. Patent No. 7,972,404 - Air cleaner arrangements; components thereof; and, methods

  • Issued: July 5, 2011

The Invention Explained

  • Problem Addressed: The patent background does not specify a particular problem, but the summary describes features that provide for "secure installation of primary filter cartridges" (’404 Patent, col. 2:48-51).
  • The Patented Solution: The invention describes an air cleaner assembly with a mechanical keying system, termed a "projection/receiver arrangement," comprising interacting features on both the filter cartridge and the housing (’404 Patent, Abstract). The cartridge's seal member includes a "pocket" that must align with a corresponding "projection" on the housing to allow for full and proper installation, preventing incorrect orientation and ensuring a proper seal is formed (’404 Patent, col. 26:1-17). The complaint reproduces the patent's Figure 6, which illustrates a cross-section of such a seal and pocket arrangement (Compl. p. 11).
  • Technical Importance: This security feature helps prevent service errors where an incorrect or improperly oriented filter might be installed, which could lead to an incomplete seal and allow unfiltered air to damage the engine.

Key Claims at a Glance

  • The complaint asserts at least independent Claim 1 (Compl. ¶59).
  • The essential elements of independent Claim 1 include:
    • An air cleaner assembly comprising a housing and a removable air filter cartridge.
    • A projection/receiver arrangement with a first member on the housing and a second member on the cartridge.
    • The second member on the cartridge comprises a pocket arrangement with at least one "receiving pocket."
    • The receiving pocket is defined as a "closed interior pocket," is positioned "radially inwardly" from the perimeter of the pinch seal, and extends further toward a flow face than adjacent portions of the seal.

U.S. Patent No. 8,636,820 - Air filter arrangement

  • Issued: January 28, 2014
  • Technology Synopsis: The patent relates to air filter arrangements with stacked filter media. The invention includes an improved housing seal where a portion of the seal extends across opposite sides of the filter at an angle relative to the flow direction (Compl. ¶33; ’820 Patent, Abstract).
  • Asserted Claims: At least Claim 1 and Claim 14 (Compl. ¶¶70, 76).
  • Accused Features: The complaint alleges that the Torque Parts product TR513-EF infringes at least Claim 1 of the ’820 patent (Compl. ¶70).

U.S. Patent No. 8,709,119 - Air filter cartridge and air cleaner assembly

  • Issued: April 29, 2014
  • Technology Synopsis: The patent describes an air filter arrangement with stacked filter media and an improved seal. The seal includes a "pinch seal lip defining a trough" and sections that extend along a side of the filter at an angle (Compl. ¶35; ’119 Patent, Abstract).
  • Asserted Claims: At least Claim 1 (Compl. ¶82).
  • Accused Features: The complaint alleges that the Torque Parts product TR535-EF infringes at least Claim 1 of the ’119 patent (Compl. ¶82).

U.S. Patent No. 10,512,868 - Filter cartridges; air cleaner assemblies; housings; features; components; and, methods

  • Issued: December 24, 2019
  • Technology Synopsis: The patent relates to an air filter arrangement with an improved engagement mechanism between the cartridge and its housing. The invention includes "receiving pockets" on the filter cartridge for proper installation and to prevent inadvertent installation of an incorrect cartridge (’868 Patent, Abstract; Compl. ¶37).
  • Asserted Claims: At least Claim 1 (Compl. ¶93).
  • Accused Features: The complaint alleges that Torque Parts products TR504-EF and TR537-EF infringe at least Claim 1 of the ’868 patent (Compl. ¶93).

III. The Accused Instrumentality

Product Identification

The accused instrumentalities are Torque Parts engine air filter cartridges, specifically models TR080-EF, TR504-EF, TR506-EF, TR513-EF, TR534-EF, TR535-EF, and TR537-EF (Compl. ¶38).

Functionality and Market Context

The complaint alleges the accused products are "copies" of Donaldson's patented products and are advertised as "direct replacement parts" (Compl. ¶3). They are sold by Defendant Torque Parts and distributed by Defendant Expedited Parts, which operates under the name AftermarketUS (Compl. ¶¶5, 15). The complaint provides side-by-side photographs comparing the Donaldson product and the "Torque Parts Copy," illustrating a high degree of visual similarity in overall shape, filter media configuration, and molded end cap features (Compl. pp. 2-4). For example, the top image on page 2 of the complaint depicts an accused filter with a blue, fluted filter media and a black molded frame that is visually nearly identical to the Donaldson product shown alongside it (Compl. p. 2).

IV. Analysis of Infringement Allegations

The complaint references infringement claim charts in Exhibits 6-12, which are not included in the provided court filing. Therefore, the infringement allegations are summarized below in prose.

’419 Patent Infringement Allegations

The complaint alleges that Torque Parts products TR080-EF and TR534-EF directly infringe at least Claim 1 of the ’419 patent (Compl. ¶47). The narrative theory is that the accused products are "copies" of Donaldson's products and thus embody the claimed invention (Compl. ¶3). The patent claims a specific filter geometry including a "recessed" flow face and an opposing face with a "central apex" (’419 Patent, Claim 1). The visual evidence provided in the complaint, such as the photograph on page 4, depicts an accused filter with a shape that includes a recessed face and projecting sides, features consistent with the patent's description (Compl. p. 4).

’404 Patent Infringement Allegations

The complaint alleges that Torque Parts product TR506-EF directly infringes at least Claim 1 of the ’404 patent (Compl. ¶59). The infringement theory is similarly based on direct copying of Donaldson's patented designs (Compl. ¶3). The patent claims an assembly with a "projection/receiver arrangement" where the filter cartridge has a "closed interior pocket" as part of its seal structure (’404 Patent, Claim 1). The photographs on page 3 of the complaint show complex molded features on the housing of an accused product, which may correspond to these claimed security and alignment features (Compl. p. 3).

Identified Points of Contention

  • Scope Questions: The case may present questions of definitional scope. For the ’419 patent, a potential issue is whether the geometry of the accused filters meets the specific structural requirements of a "recessed" face and "central apex" as construed by the court. For the ’404 patent, a key question will be whether the molded features on the accused filters constitute a "closed interior pocket" that is "radially inwardly from the outer perimeter of the pinch seal portion," as required by the claim language.
  • Technical Questions: While the complaint’s photographs suggest a high degree of visual similarity, a central evidentiary question will be whether technical analysis confirms that the accused products meet every limitation of the asserted claims. The analysis will likely focus on precise measurements, material composition, and the functional interaction between the accused filters and their intended housings.

V. Key Claim Terms for Construction

’419 Patent, Claim 1: "central apex"

  • The Term: "central apex"
  • Context and Importance: This geometric term appears in two limitations of Claim 1, defining the shape of both the projecting flow face and the side pieces. Its construction is critical to defining the overall three-dimensional structure required for infringement. Practitioners may focus on this term because Defendants could argue their products have a rounded or general projection that does not rise to the level of a distinct "apex."
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specification describes the feature functionally as providing an "arrow shape" that helps guide the cartridge into the housing, which could support a construction not limited to a sharp geometric point (’419 Patent, col. 12:40-45).
    • Evidence for a Narrower Interpretation: The patent figures, such as Figure 10, consistently depict a distinct V-shape with a clear vertex (’419 Patent, Fig. 10). The plain meaning of "apex" suggests the highest point or vertex, which could support a narrower construction requiring a more defined point rather than a broad curve.

’404 Patent, Claim 1: "closed interior pocket"

  • The Term: "closed interior pocket"
  • Context and Importance: This term is the core of the claimed "projection/receiver arrangement" intended to ensure proper installation. Infringement of Claim 1 hinges on whether the accused filter's seal includes a structure meeting this definition. Practitioners may focus on this term because its components—"closed" and "interior"—invite arguments about the degree of enclosure required.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specification describes the pocket as part of a "security, housing closure, inhibition arrangement," suggesting its definition could be informed by its function of preventing improper installation (’404 Patent, col. 26:1-3).
    • Evidence for a Narrower Interpretation: The claim itself provides structural limitations, requiring the pocket to be "closed" and "interior," and to extend further toward a flow face than adjacent seal portions (’404 Patent, Claim 1). The figures depict a distinct, molded recess within the body of the seal arrangement, not merely an open channel or groove, supporting a construction that requires some degree of enclosure (’404 Patent, Fig. 18).

VI. Other Allegations

  • Indirect Infringement: The complaint alleges both induced and contributory infringement against both Defendants (Compl. ¶¶6-8, 39). Inducement is alleged based on Defendants selling the filters to customers with the knowledge and intent that they will be used in an infringing manner (Compl. ¶7). Contributory infringement is alleged on the basis that the accused filter cartridges are material components of the patented assemblies, are not staple articles of commerce, and have no substantial non-infringing use (Compl. ¶8).
  • Willful Infringement: Willfulness is alleged for all five patents-in-suit (Compl. ¶¶55, 66, 78, 89, 100). The allegations are based on Defendants' continued infringement "notwithstanding actual knowledge of the... patent as a result of the Amazon APEX proceedings" as well as through service of the complaint itself, allegedly without a good faith basis to believe their activities do not infringe (Compl. ¶55).

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

  • A core issue will be one of structural identity: The complaint presents this as a case of direct copying, supported by striking visual evidence. The central question for the court will be whether expert analysis and discovery confirm that the accused "copies" meet every technical limitation of the asserted claims, or if subtle but material differences in geometry, dimensions, or materials create a viable non-infringement defense.
  • A key legal battle may center on definitional scope, particularly concerning the mechanical interface features. The case may turn on questions such as whether a recess on an accused filter constitutes a "closed interior pocket" (’404 patent) or whether a projection is properly defined as a "central apex" (’419 patent), issues that will be resolved during claim construction.
  • A critical question for damages will be one of willfulness: Given the complaint’s allegations of successful pre-suit enforcement actions via Amazon's APEX program, the court will have to determine if Defendants had pre-suit knowledge of the patents and a corresponding duty to avoid infringement, and whether their subsequent conduct was egregious enough to warrant enhanced damages.