DCT
1:18-cv-00667
Diesel Tech LLC v. Navistar Inc
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Diesel Technologies LLC (Delaware)
- Defendant: Navistar, Inc. (Delaware)
- Plaintiff’s Counsel: Devlin Law Firm LLC
- Case Identification: 1:18-cv-00667, D. Del., 05/02/2018
- Venue Allegations: Venue is based on Defendant's incorporation in the State of Delaware.
- Core Dispute: Plaintiff alleges that Defendant’s heavy- and medium-duty trucks, which incorporate a specific Cummins engine and aftertreatment system, infringe a patent related to a method for chemically cleaning ash deposits from diesel particulate filters during vehicle operation.
- Technical Context: The technology concerns diesel engine exhaust aftertreatment systems, which are critical for meeting government emissions regulations by trapping and removing particulate matter.
- Key Procedural History: The complaint does not mention any prior litigation, inter partes review (IPR) proceedings, or specific licensing history related to the patent-in-suit.
Case Timeline
| Date | Event |
|---|---|
| 2003-12-18 | U.S. Patent No. 8,474,246 Priority Date (German filing) |
| 2013-07-02 | U.S. Patent No. 8474246 Issued |
| 2018-05-02 | Complaint Filed |
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 trap and burn off combustible soot, but they also accumulate non-combustible ash, primarily from engine lubricant additives. Over time, this ash clogs the filter, increasing exhaust backpressure, harming engine performance, and eventually requiring the filter to be physically removed for cleaning or replacement (’246 Patent, col. 1:30-53).
- The Patented Solution: The patent describes a method to reduce this ash buildup during vehicle operation. The method involves an "ash reducing procedure" where the DPF is heated and a "reducing agent" (such as hydrocarbons from fuel) is introduced into the exhaust stream (’246 Patent, col. 2:6-15). This agent is intended to create a reducing chemical environment that reacts with the non-metallic components of the ash (e.g., sulfates, phosphates), converting them into volatile compounds that can be expelled from the filter with the exhaust gas (’246 Patent, col. 2:1-15; col. 5:35-55).
- Technical Importance: The invention aims to extend the operational life of DPFs and reduce the need for costly and time-consuming off-board servicing, a significant logistical and economic challenge in the management of modern diesel fleets (’246 Patent, col. 1:48-53).
Key Claims at a Glance
- The complaint asserts claims 1-4 (Compl. ¶11).
- Independent Claim 1 recites the essential elements of the method:
- Operating a particle filter that collects soot and ash and is periodically re-conditioned by a "soot-burn off procedure."
- Performing an "ash reducing procedure" that comprises:
- heating the particle filter;
- supplying a "reducing agent" to the filter with the exhaust gas;
- wherein the reducing agent "reacts with the ash deposits so as to chemically convert" them;
- such that "at least non-metallic constituent parts of the ash deposits are carried out of the particle filter" by the exhaust gas.
- The complaint does not explicitly reserve the right to assert additional claims but asserts dependent claims 2-4, which further specify the source of the reducing agent (fuel) and the location of its injection (upstream of the filter).
III. The Accused Instrumentality
Product Identification
- The "Accused Instrumentalities" are Navistar's HV Series and Durastar trucks that are equipped with a Cummins L9 engine (Compl. ¶11). The complaint includes a screenshot from Navistar's website showing these truck models offered with the Cummins L9 engine (Compl. Fig. 1).
Functionality and Market Context
- The complaint alleges these trucks utilize a Cummins-supplied "Single Module Aftertreatment" system, which includes a Diesel Particulate Filter (DPF) controlled by a high-capacity Electronic Control Module (ECM) (Compl. ¶14; Fig. 2, Fig. 3). The system is alleged to perform "active self-regeneration" by injecting a small amount of fuel upstream of the DPF. This action raises exhaust temperatures to oxidize, or burn off, collected soot (Compl. Fig. 5). The complaint alleges that this standard regeneration process also performs the patented ash-reduction method (Compl. ¶13, ¶14). The HV Series and Durastar are marketed as "severe duty" and "medium-duty" workhorses, respectively, suggesting their use in commercial and industrial applications where engine uptime is critical (Compl. Fig. 1).
IV. Analysis of Infringement Allegations
'246 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| A method of operating a particle filter (4) in an exhaust system... wherein the particle filter (4), which collects soot particles and ashes, is re-conditioned, in intervals, by a soot-burn off procedure... | The accused trucks' aftertreatment system performs "active self-regeneration" to remove collected Particulate Matter (PM), which the complaint equates to a "soot burn-off procedure" that occurs in intervals (Compl. Fig. 5, Fig. 6). | ¶14 | col. 4:30-40 |
| but wherein, in addition to soot, also non-combustible ashes are deposited during operation of the internal combustion engine... | Ash, described as "incombustible material derived from the additive pack in the lube oil," is trapped in the DPF during normal engine operation (Compl. Fig. 7). | ¶14 | col. 5:1-19 |
| said method comprising the steps of: reducing, in an ash reducing procedure (A), the mass of the ash deposits in the particle filter by heating the particle filter... | The active regeneration process raises exhaust temperatures, which is alleged to constitute heating the filter for an ash reducing procedure. The complaint references an external academic paper showing high temperature exposure reduces ash volume (Compl. Fig. 8, Fig. 9). | ¶14 | col. 2:27-30 |
| and supplying to the particle filter, together with the exhaust gas of the internal combustion engine (1), a reducing agent... | During active regeneration, a "small amount of fuel (reducing agent)" is injected upstream of the Cummins Particulate Filter (Compl. Fig. 8). | ¶14 | col. 2:21-26 |
| which reacts with the ash deposits so as to chemically convert the ash deposits... | The complaint alleges that the injected fuel "reacts with the ash deposits so as to chemically convert the ash deposits" (Compl. ¶13). It supports this by citing an academic paper showing decomposition temperatures for various ash components like Calcium Sulfate and Zinc Phosphate (Compl. Fig. 9). | ¶13 | col. 2:8-12 |
| such that at least non-metallic constituent parts of the ash deposits are carried out of the particle filter (4) by the exhaust gas. | The complaint alleges this chemical conversion results in "non-metallic constituent parts of the ash deposits" being "carried out of the particle filter" (Compl. ¶13). It also states that "ash is reduced when the PM is oxidized burning the combustible molecules from the ash off and leaving a reduced amount of ash" (Compl. Fig. 8). | ¶13 | col. 2:11-15 |
Identified Points of Contention
- Scope Questions: A central question is whether the accused products' standard "active regeneration"—a process designed to oxidize soot in an oxygen-rich environment—can meet the claim requirements for an "ash reducing procedure" that uses a "reducing agent." The patent specification appears to describe a distinct chemical process involving the creation of a reductive atmosphere to convert ash, which may be fundamentally different from the oxidizing atmosphere required for soot combustion (’246 Patent, col. 5:45-49).
- Technical Questions: The complaint alleges that injecting fuel for soot regeneration constitutes the claimed ash reduction method, but it may raise the question of what evidence shows this process creates the necessary reductive chemical conditions within the filter. The complaint’s description that "ash is reduced when the PM is oxidized" appears to conflate two distinct chemical processes (Compl. Fig. 8). The infringement theory relies on an external academic paper to show that ash can be decomposed at high temperatures, but it does not directly allege how the accused Cummins system specifically achieves the claimed chemical conversion and expulsion of non-metallic ash components (Compl. Fig. 9).
V. Key Claim Terms for Construction
The Term: "reducing agent"
- Context and Importance: The definition of this term is critical. The infringement theory hinges on equating the fuel injected for an oxidative soot burn-off with the "reducing agent" required for the claimed reductive ash conversion. Practitioners may focus on this term because the chemical environment (oxidizing vs. reducing) in which the agent is supplied appears to be a key technical distinction between the prior art soot removal and the patented invention.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The patent states that fuel used for operating the engine can be employed as the reducing agent, and that hydrocarbons are a usable agent (’246 Patent, col. 2:35-37; col. 5:50-51). This could support an argument that any unburned fuel qualifies, regardless of the overall exhaust environment.
- Evidence for a Narrower Interpretation: The specification repeatedly frames the invention in the context of establishing "reducing conditions" or an "overall reducing atmosphere" in the DPF to decompose ash (’246 Patent, col. 2:30-34; col. 5:45-49). This language may support an interpretation that the "reducing agent" must be supplied in a manner that actually creates a net reductive chemical environment, as opposed to simply being a fuel source for an oxidative combustion event.
The Term: "ash reducing procedure"
- Context and Importance: This term's construction will determine whether the accused "active regeneration" for soot removal can also be considered the claimed procedure. The case may turn on whether any process that incidentally affects ash qualifies, or if the procedure must be a specific set of steps intended to achieve the chemical reduction of ash as described in the patent.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: A party could argue that if the accused regeneration cycle results in any ash reduction, it inherently performs an "ash reducing procedure," and the label is not limiting.
- Evidence for a Narrower Interpretation: The patent consistently distinguishes between the "soot burn-off procedure" and the "ash reducing procedure," even when they are performed in connection with each other (e.g., claim 7). The specification suggests they are distinct processes with different chemical objectives (oxidizing soot vs. reducing ash) (’246 Patent, col. 6:40-52). This could support a narrower definition requiring a process with the specific characteristics and purpose of ash reduction.
VI. Other Allegations
- Indirect Infringement: The complaint alleges that Navistar induces infringement by its "partners, clients, customers, and end users" who use the accused trucks (Compl. ¶23). Knowledge and intent are alleged to have existed "since at least the time Defendant received notice," which the complaint identifies as the filing of the lawsuit itself (Compl. ¶22, ¶23).
- Willful Infringement: The allegation of willfulness is based on a theory of post-suit knowledge, asserting that infringement has been willful "since at least the time Defendant received notice" via the filing of the complaint (Compl. ¶22, ¶25).
VII. Analyst’s Conclusion: Key Questions for the Case
- A core issue will be one of chemical-technical definition: can the accused trucks' "active regeneration," a standard process designed to oxidize soot in an oxygen-rich environment, be construed as the claimed "reductive ash conversion method"? The case may depend on whether supplying fuel as a combustion source for heating is legally and factually equivalent to supplying a "reducing agent" to create the specific chemical reactions described in the patent.
- A key evidentiary question will be one of functional proof: what evidence demonstrates that the accused Cummins L9 aftertreatment system, during its standard regeneration cycle, actually performs the claimed chemical conversion of non-metallic ash components (e.g., sulfates, phosphates) into volatile compounds that are then expelled from the filter? The complaint's reliance on marketing materials for soot removal and a general academic paper on ash chemistry raises the question of whether direct evidence of the claimed process occurring in the accused product will be presented.