Diesel Tech LLC v. Deere & Co

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Diesel Technologies LLC (Delaware)
  • Defendant: Deere & Company (Delaware)
  • Plaintiff’s Counsel: DEVLIN LAW FIRM LLC
• Case Identification: 3:25-cv-50027, N.D. Ill., 01/17/2025
• Venue Allegations: Venue is based on Defendant’s established places of business and corporate offices within the Northern District of Illinois, where it is alleged to regularly transact business.
• Core Dispute: Plaintiff alleges that Defendant’s diesel engines incorporating an Exhaust After-Treatment System infringe a patent related to a method for chemically cleaning non-combustible ash from diesel particulate filters during vehicle operation.
• Technical Context: The technology addresses the problem of ash accumulation in diesel particulate filters, a critical component for meeting modern vehicle emissions standards, by providing a method to extend filter life and reduce costly maintenance.
• Key Procedural History: The complaint does not mention any prior litigation involving the patent-in-suit, any post-grant validity challenges, or any pre-existing licensing agreements between the parties.

Case Timeline

Date	Event
2003-12-18	’246 Patent Priority Date
2013-07-02	’246 Patent Issue Date
2025-01-17	Complaint Filing Date

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

U.S. Patent No. 8,474,246 - "METHOD OF OPERATING A PARTICLE FILTER IN THE EXHAUST SYSTEM OF A MOTOR VEHICLE'S INTERNAL COMBUSTION ENGINE," issued July 2, 2013

The Invention Explained

• Problem Addressed: Diesel particulate filters (DPFs) effectively capture soot from engine exhaust, which can be periodically burned off in a "regeneration" cycle. However, these filters also accumulate non-combustible inorganic ash from engine oil and fuel additives. This ash cannot be burned off and its gradual buildup increases exhaust backpressure, degrades engine performance, and ultimately necessitates complex and costly filter replacement ('246 Patent, col. 1:29-53).
• The Patented Solution: The invention describes a method to actively reduce the amount of collected ash during vehicle operation, extending the filter's service life. The method involves heating the DPF and introducing a "reducing agent" along with the exhaust gas. This agent is described as reacting with the non-metallic components of the ash (e.g., sulfates and phosphates), chemically converting them into volatile compounds that are then expelled from the filter with the exhaust gas ('246 Patent, Abstract; col. 2:1-9).
• Technical Importance: By enabling the in-situ chemical removal of performance-degrading ash, the invention claims to provide a less maintenance-intensive and more cost-effective solution for long-term compliance with vehicle emissions standards (Compl. ¶17, ¶19).

Key Claims at a Glance

• The complaint asserts infringement of independent claim 1 and dependent claims 2-4 and 7 ('246 Patent, col. 8:10-51; Compl. ¶27).
• Independent Claim 1 recites:
  • A method of operating a particle filter in a vehicle's exhaust system, which already undergoes periodic "soot-burn off" procedures.
  • The method comprises an "ash reducing procedure" to reduce the mass of ash deposits.
  • This procedure involves heating the filter.
  • It also involves supplying a "reducing agent" with the exhaust gas.
  • The reducing agent reacts with the ash to "chemically convert" it.
  • This conversion allows at least the "non-metallic constituent parts" of the ash to be carried out by the exhaust gas.
• The complaint’s assertion of dependent claims suggests the infringement theory includes using engine fuel as the reducing agent (Claim 2), adding it upstream of the filter (Claim 3) via fuel injection (Claim 4), and performing the ash reduction in connection with a soot-burn-off procedure (Claim 7) (Compl. ¶30-37).

III. The Accused Instrumentality

Product Identification

• The Accused Instrumentalities are identified as the John Deere JD9X Tier 4 Engine and other similar engines (JD9P, JD14P, JD14X) that contain an Exhaust After-Treatment System (EATS) which includes a Diesel Particulate Filter (DPF) (Compl. ¶27).

Functionality and Market Context

• The complaint alleges these engines are used in construction vehicles and other motor vehicles (Compl. ¶18). The core of the infringement allegation is that these engines' EATS functionality performs the patented method of ash reduction (Compl. ¶28-29). The complaint asserts that this technology provides significant commercial value to Deere by reducing DPF replacement costs and enabling more effective compliance with emissions standards (Compl. ¶17).

IV. Analysis of Infringement Allegations

Plaintiff’s infringement theory, as outlined in the complaint, asserts that Defendant’s engines equipped with an EATS and DPF directly infringe at least claim 1 of the ’246 patent (Compl. ¶29). The complaint alleges that these systems perform a method that reduces the mass of ash in the DPF by heating the filter and supplying a reducing agent that chemically converts the ash, allowing parts of it to be expelled with the exhaust gas (Compl. ¶28). The allegations for dependent claims further specify the accused method. For example, the complaint alleges the accused systems use engine fuel as the reducing agent (implicating Claim 2), introduce this agent into the exhaust stream upstream of the DPF (implicating Claim 3) via fuel injection (implicating Claim 4), and conduct the ash reduction procedure in connection with a soot-burn-off procedure (implicating Claim 7) (Compl. ¶30-37).

The complaint references an attached claim chart in Exhibit B, which was not provided with the filed complaint. Therefore, the infringement theory is summarized below in prose. No probative visual evidence provided in complaint.

Identified Points of Contention

• Technical Question: A central factual dispute may concern the actual chemical process occurring within the accused Deere engines. The court will need to consider what evidence demonstrates that the accused systems perform a specific "chemical conversion" of non-metallic ash components (e.g., sulfates, phosphates), as taught by the patent ('246 Patent, col. 5:46-55), rather than a high-temperature regeneration cycle that might physically dislodge ash without the claimed chemical reaction.
• Scope Question: The infringement analysis raises the question of whether the accused process constitutes a distinct "ash reducing procedure" as recited in the claim, which is separate from the "soot-burn off procedure" also mentioned ('246 Patent, col. 8:10-16). The patent contemplates that the ash reduction occurs in a "reducing atmosphere," whereas a soot burn-off occurs under "oxidizing condition[s]" ('246 Patent, col. 7:40-43), suggesting a potential basis for distinguishing the two procedures.

V. Key Claim Terms for Construction

The Term: "reducing agent"

• Context and Importance: This term is fundamental to the invention. The outcome of the case may depend on whether the substance used in Deere's EATS (e.g., diesel fuel) qualifies as a "reducing agent" that performs the function required by the claim—the chemical conversion of ash deposits (Compl. ¶28).
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The specification states that "gaseous reducing compounds such as hydrogen, carbon monoxide or hydrocarbons may be used" ('246 Patent, col. 2:23-24) and that "a particular fuel is used for operating the engine" can be the reducing agent ('246 Patent, col. 2:35-36). This language may support construing the term to broadly cover hydrocarbons like diesel fuel.
  • Evidence for a Narrower Interpretation: The patent consistently frames the function of the "reducing agent" as causing a "chemical conversion" of "non-metallic ash components" ('246 Patent, col. 2:1-4). A party could argue the term should be limited to substances that achieve this specific chemical decomposition of ash, not just any substance that facilitates a high-temperature cleaning.

The Term: "ash reducing procedure"

• Context and Importance: Claim 1 recites both a "soot-burn off procedure" and an "ash reducing procedure," creating a potential distinction that is critical for infringement. If Deere's system is found to perform only a single, undifferentiated regeneration process, it may raise questions of whether it performs the distinctly claimed "ash reducing procedure" (Compl. ¶28; ’246 Patent, col. 8:10-25).
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: Claim 7 teaches that an "ash reducing procedure (A) is performed in connection with a soot-burn-off procedure (R)" ('246 Patent, col. 8:46-49). This may support an interpretation where the two procedures can be integrated or occur concurrently as part of a single event.
  • Evidence for a Narrower Interpretation: The specification notes that an ash reduction is preferably performed in a "reducing atmosphere," whereas a soot burn-off occurs under an "oxidizing condition" ('246 Patent, col. 7:40-43). This chemical difference could support an argument that the "ash reducing procedure" must be a distinct and separately identifiable process with its own unique operating conditions.

VI. Other Allegations

• Indirect Infringement: The complaint alleges induced infringement, stating that Deere encourages infringement by its customers and partners through the provision of "instruction materials, training, and services" for the Accused Instrumentalities (Compl. ¶41). Knowledge and intent are alleged to exist "since at least the date Defendant received notice" of the complaint (Compl. ¶41).
• Willful Infringement: Willfulness is alleged based on infringement occurring after Defendant received notice of the lawsuit: "Since receiving notice of this Complaint, Defendant's infringement has been willful" (Compl. ¶42). The complaint does not allege pre-suit knowledge of the patent.

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

• A core issue will be one of chemical mechanism: Can Plaintiff provide evidence that the accused Deere engine systems achieve the specific "chemical conversion" of non-metallic ash components central to the patent's teachings, or does the accused process amount to a conventional high-temperature filter cleaning that may have an incidental, but not chemically transformative, effect on ash deposits?
• A second key issue will be one of claim scope and procedural distinction: Will the term "ash reducing procedure" be construed to require a distinct process with unique operating parameters (such as a reducing atmosphere), or can it be read broadly to cover a stage within a single, unified regeneration cycle? The answer will determine whether Deere's single-system approach meets the multipart procedural limitations of Claim 1.