DCT
1:18-cv-01083
Cummins Inc v. Diesel Tech LLC
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Cummins Inc. & Cummins Emission Solutions, Inc. (Indiana)
- Defendant: Diesel Technologies LLC (Delaware)
- Plaintiff’s Counsel: Young, Conaway, Stargatt & Taylor, LLP
- Case Identification: 1:18-cv-01083, D. Del., 07/23/2018
- Venue Allegations: Venue is alleged to be proper in the District of Delaware because Defendant is a Delaware limited liability company and because related lawsuits were previously filed in the district.
- Core Dispute: Plaintiff seeks a declaratory judgment that its diesel engine and aftertreatment products do not infringe Defendant's patent related to a method for reducing ash deposits in diesel particle filters, and that the patent-in-suit is invalid.
- Technical Context: The technology concerns exhaust aftertreatment systems for diesel engines, specifically methods to extend the operational life of diesel particulate filters by actively removing accumulated, non-combustible ash.
- Key Procedural History: This declaratory judgment action was filed after Defendant, Diesel Technologies, sued two of Plaintiff's major customers, Navistar and Paccar, in the same court for infringing the patent-in-suit by using vehicles equipped with Plaintiff's engines. The complaint also raises invalidity arguments based on prior art.
Case Timeline
| Date | Event |
|---|---|
| 2003-04-10 | Publication date of "Hirota" prior art reference |
| 2003-12-18 | U.S. Patent No. 8,474,246 Priority Date |
| 2013-07-02 | U.S. Patent No. 8,474,246 Issue Date |
| 2018-05-02 | Diesel Technologies files infringement suit against Navistar |
| 2018-05-15 | Diesel Technologies files infringement suit against Paccar |
| 2018-07-23 | Complaint for Declaratory Judgment filed by Cummins |
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
- Patent Identification: 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 soot, which can be periodically burned off in a process called regeneration. However, these filters also accumulate non-combustible inorganic ash from lubricating oil and fuel additives. This ash buildup is not removed by normal regeneration, leading to a gradual increase in exhaust backpressure that eventually degrades engine performance and requires costly filter replacement or off-vehicle cleaning ('246 Patent, col. 1:29-53).
- The Patented Solution: The patent describes a method to chemically reduce the mass of collected ash during vehicle operation, extending the filter's life. The method involves an "ash reducing procedure" where the DPF is heated and a "reducing agent" is supplied with the exhaust gas. This agent reacts with non-metallic components of the ash (e.g., sulfates, phosphates), converting them into volatile compounds that are then expelled from the filter with the exhaust flow ('246 Patent, Abstract; col. 1:60-2:4). This procedure is distinct from a standard soot burn-off, which occurs in an oxidizing environment ('246 Patent, col. 7:40-44).
- Technical Importance: The invention proposes an on-board solution to mitigate DPF ash loading, a significant long-term maintenance and cost issue for operators of diesel vehicles subject to modern emissions standards ('246 Patent, col. 1:50-59).
Key Claims at a Glance
- The complaint notes that the underlying lawsuits against its customers assert infringement of claims 1-4 and 7, and the complaint itself focuses its non-infringement and invalidity arguments on independent claim 1 (Compl. ¶¶10, 13, 19, 23).
- Independent Claim 1 of the ’246 Patent recites the following essential elements:
- A method of operating a particle filter in a vehicle exhaust system, where the filter collects soot and ash and is periodically reconditioned by a soot burn-off procedure.
- The method comprises the step of "reducing, in an ash reducing procedure (A), the mass of the ash deposits in the particle filter."
- This reduction is achieved by "heating the particle filter" and "supplying to the particle filter, together with the exhaust gas... a reducing agent."
- The reducing agent "reacts with the ash deposits so as to chemically convert" them.
- This chemical conversion results in "at least non-metallic constituent parts of the ash deposits" being "carried out of the particle filter... by the exhaust gas."
- The complaint seeks a declaratory judgment of non-infringement and invalidity as to all claims of the ’246 Patent (Compl., Prayer for Relief).
III. The Accused Instrumentality
Product Identification
- Cummins L9, Paccar PX-9, and Cummins ISX 15 engines and their corresponding Aftertreatment System products (Compl. ¶¶12, 15).
Functionality and Market Context
- These products are diesel engines and exhaust aftertreatment systems used in heavy-duty commercial trucks manufactured by companies such as Navistar and Paccar (Compl. ¶¶10, 13). The complaint does not detail the technical operation of the accused products, but rather asserts that they do not perform the method claimed in the ’246 Patent (Compl. ¶19). The core of the complaint is that a justiciable controversy exists because Diesel Technologies has accused these specific Cummins products of infringement in lawsuits filed against Cummins's customers (Compl. ¶16).
IV. Analysis of Infringement Allegations
As this is a complaint for declaratory judgment of non-infringement, the "allegations" are Plaintiff Cummins's assertions that its products do not meet the patent's claim limitations. The central point of non-infringement is articulated as a failure to practice the key "ash reducing procedure" step (Compl. ¶19).
No probative visual evidence provided in complaint.
’246 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Denied Infringing Functionality (per Cummins) | Complaint Citation | Patent Citation |
|---|---|---|---|
| reducing, in an ash reducing procedure (A), the mass of the ash deposits in the particle filter... | The complaint asserts that the accused Cummins products do not perform this step. | ¶19 | col. 8:17-20 |
| by heating the particle filter and supplying to the particle filter, together with the exhaust gas... a reducing agent... | The complaint's general denial of practicing the "ash reducing procedure" encompasses the denial of supplying a "reducing agent" to perform the claimed function. | ¶19 | col. 8:20-23 |
| which reacts with the ash deposits so as to chemically convert the ash deposits such that at least non-metallic constituent parts... are carried out... by the exhaust gas. | The complaint states that the accused products do not chemically convert and carry out ash deposits in the manner claimed. | ¶19 | col. 8:23-27 |
Identified Points of Contention
- Technical Question: The primary factual dispute will likely be whether the standard regeneration cycle of the accused Cummins aftertreatment systems creates the chemical conditions required by the claims. The complaint's denial suggests that its systems, designed for an oxidizing soot burn-off, do not supply a "reducing agent" that "chemically convert[s]" ash in a reducing reaction as described in the patent (Compl. ¶19; ’246 Patent, col. 7:40-44).
- Scope Questions: The case may turn on whether a standard soot regeneration process, which may involve some unburnt hydrocarbons (a potential reducing agent), inherently performs the claimed "ash reducing procedure." A key question is whether the claims require a distinct, dedicated procedure with a "reducing atmosphere," as suggested by the patent's specification, or if they can read on any operational cycle that may have an incidental effect on ash deposits.
V. Key Claim Terms for Construction
The Term: "reducing agent"
- Context and Importance: The identity and function of the "reducing agent" are central to the invention. The infringement analysis will depend on whether any substances present in the accused systems' exhaust streams during operation qualify as a "reducing agent" that performs the claimed function of chemically converting ash.
- Intrinsic Evidence for a Broader Interpretation: The patent states that the reducing agent can be "generated from the fuel on board of the vehicle" and may be provided via "incompletely burned fuel generated by under-stoichiometric operation of the internal combustion engine" ('246 Patent, col. 2:35-38; col. 8:36-40). This could support an argument that any unburnt hydrocarbons meet the definition.
- Intrinsic Evidence for a Narrower Interpretation: The patent repeatedly frames the "ash reducing procedure" as occurring in a "reducing atmosphere," which it explicitly places "in contrast to the oxidizing condition under which the soot burn-off occurs" ('246 Patent, col. 7:40-44). This suggests the "reducing agent" must be supplied in sufficient quantity to create an overall reducing environment, not merely be incidentally present during an otherwise oxidizing event.
The Term: "ash reducing procedure (A)"
- Context and Importance: This term defines the entire inventive process. Whether this must be a discrete, separately initiated procedure or can be an inherent part of another process (like soot regeneration) is critical. Practitioners may focus on this term because the patent's own figures and description appear to treat it as a distinct event.
- Intrinsic Evidence for a Broader Interpretation: Claim 7 recites performing the ash reducing procedure "in connection with a soot-burn-off procedure," which could be interpreted to mean concurrently or as part of the same overall cycle ('246 Patent, col. 8:46-49).
- Intrinsic Evidence for a Narrower Interpretation: The patent's Figure 2 depicts the "ash reducing procedure (A)" as a single event occurring after multiple, separate "soot particle burn-off procedures (R)" ('246 Patent, Fig. 2). The specification further explains that since ash accumulates much more slowly than soot, it is "advantageous to perform the ash reducing procedure only in connection with every fifth to tenth soot burn-off procedure," strongly implying it is a separate and less frequent operation ('246 Patent, col. 4:32-36).
VI. Other Allegations
- Indirect Infringement: Cummins seeks a declaratory judgment that it has not contributed to or induced infringement of the ’246 Patent (Compl. ¶18; Prayer for Relief (b), (c)). Such claims by Diesel Technologies would be premised on the alleged direct infringement by Cummins's customers (Navistar and Paccar), who incorporate the accused Cummins products into their vehicles and operate them (Compl. ¶¶10-15).
VII. Analyst’s Conclusion: Key Questions for the Case
- A core issue will be one of claim scope and process distinction: Does the claimed "ash reducing procedure" require a distinct, intentionally initiated process step that creates a "reducing atmosphere," as contrasted in the patent's specification with a standard "oxidizing" soot burn-off? Or can the claim be interpreted to cover any chemical reactions that might incidentally reduce ash during a conventional, oxidative DPF regeneration cycle?
- A key evidentiary question will be one of operational chemistry: What are the actual chemical conditions present within the particulate filters of the accused Cummins products during all operational modes, including soot regeneration? The outcome may depend on whether Cummins can factually establish that its systems maintain a fundamentally oxidizing environment, thereby precluding the function of a "reducing agent" to "chemically convert" ash as required by a plausible construction of the claims.