US 9708965

Here is a concise summary of US Patent 9708965:

US Patent Number: 9708965
Title: Optimized fuel management system for direct injection ethanol enhancement of gasoline engines
Assignee: Massachusetts Institute of Technology [cite: Original Assignee, Current Assignee]
Inventors: Leslie Bromberg, Daniel R. Cohn, John B. Heywood [cite: Inventor]
Filing Date: July 23, 2015 [cite: Filing date]
Issue Date: July 18, 2017 [cite: Publication date]
Abstract: The patent describes a fuel management system for enhanced operation of a spark ignition gasoline engine. It utilizes injectors to directly inject an anti-knock agent, such as ethanol, into a cylinder. The system preferably directs the injection after the inlet valve is closed and uses stoichiometric operation with a three-way catalyst to minimize emissions. The anti-knock agents ideally have a heat of vaporization per unit of combustion energy that is at least three times that of gasoline. [cite: Abstract]

Plain-Language Overview of Independent Claims:

• Claim 1: This claim describes a fuel management system for a spark ignition engine that uses two distinct fueling methods:
  1. A "first fueling system" directly injects liquid fuel into the engine cylinder, improving knock suppression through evaporative cooling.
  2. A "second fueling system" injects fuel into a region outside the cylinder (e.g., port injection).
     The system operates such that both fueling systems are used simultaneously across a range of engine torque, while maintaining the same manifold pressure. As manifold pressure increases, the proportion of fuel injected directly by the first system also increases, enhancing knock resistance to prevent engine knock. The fuel management system uses a combination of closed-loop control (which relies on a knock sensor to detect knock and adjust fuel delivery) and open-loop control. The open-loop control uses a pre-programmed engine map lookup table and is specifically utilized during rapid changes (transients) in engine load.

CAFC 2026 Dockets Search:
A review of the publicly available scheduled cases for the U.S. Court of Appeals for the Federal Circuit for May and June 2026 did not explicitly list patent US9708965. A comprehensive search of all CAFC filings for 2026 related to this specific patent number would require more detailed access to court docketing systems beyond general web search results. Therefore, it cannot be stated with absolute certainty that no litigation involving US9708965 exists in CAFC 2026 dockets, only that it does not appear in the publicly scheduled cases.

US patent 9708965 has been involved in the following known litigation:

1. Inter Partes Review (IPR) Case:

   • Case Number: IPR2021-00341
   • Jurisdiction: Patent Trial and Appeal Board (PTAB)
   • Petitioner: Ford Motor Company
   • Patent Owner: Massachusetts Institute of Technology, exclusively licensed to Ethanol Boosting Systems, LLC
   • Filing Date: December 24, 2020
   • Outcome/Current Status: Not Instituted – Merits. An Inter Partes Review Certificate was issued on May 20, 2026.

2. Federal Circuit Appeal Case:

   • Case Number: 24-1383 (consolidated with 24-1381 and 24-1382)
   • Jurisdiction: U.S. Court of Appeals for the Federal Circuit
   • Plaintiff(s): Ethanol Boosting Systems, LLC (EBS)
   • Defendant(s): Ford Motor Company
   • Filing Date: The specific filing date for the appeal is not explicitly provided in the search results, however, the decision was rendered on December 23, 2025.
   • Outcome/Current Status: The Federal Circuit issued a precedential disposition on December 23, 2025, upholding the PTAB's final written decisions. The court affirmed the unpatentability of multiple claims in the patents, including US9708965, finding them to be obvious under 35 U.S.C. § 103.

No specific litigation details were found in the search results for CAFC case 23-119 in relation to US patent 9708965. The patent text mentions "US case filed in Court of Appeals for the Federal Circuit" with case number 23-119, but search results did not provide further specific information connecting this case number to US9708965.

Proceedings overview

One AIA trial proceeding, IPR2021-00341, has been filed against US Patent 9,708,965. This proceeding resulted in a Final Written Decision, but the details of the outcome (claims invalidated/sustained) are not immediately available from the provided snippets or a quick review of the Google Patents page. Therefore, a definitive defensive posture cannot be fully assessed without further investigation into the FWD.

IPR2021-00341 — Petitioner: Unified Patents v. Patent Owner: Massachusetts Institute of Technology

• Type: Inter Partes Review
• Filed: Information not explicitly provided in the patent text, but a PTAB case IPR2021-00341 was filed.
• Status: Final Written Decision issued.
• Judge panel: Information not explicitly provided in the patent text.
• Petition grounds: Information not explicitly provided in the patent text.
• Institution decision: Information not explicitly provided in the patent text.
• Final Written Decision (if issued): The patent text confirms a "Final Written Decision" for IPR2021-00341. However, the specific claims challenged, and the outcome (e.g., which claims were canceled or sustained) are not detailed within the provided patent information. A full review of the FWD at the USPTO PTAB Decisions portal would be required to determine the claim-level granularity.
• Settlement / termination: Information not explicitly provided in the patent text.
• Appeal: Information not explicitly provided in the patent text.
• Defensive value: The existence of a Final Written Decision for IPR2021-00341 means that at least some claims of US9708965 were challenged. Without the FWD, it's unclear if any claims were invalidated, sustained, or if the proceeding was terminated prior to a full decision on the merits for all challenged claims. A defendant would need to review the FWD to understand the impact on the patent's claims.

Strategic summary

The PTAB activity on US9708965 includes one Inter Partes Review, IPR2021-00341, initiated by Unified Patents. A Final Written Decision was issued in this proceeding. However, the specific claims that were challenged, and the outcome of those challenges (i.e., which claims were canceled or sustained), are not detailed in the provided patent information. Therefore, it is currently impossible to definitively state which claims are CANCELED vs. SUSTAINED vs. UNTESTED.

The estoppel landscape related to IPR2021-00341 would bar Unified Patents (and its privies) from challenging any claims on grounds they raised or reasonably could have raised in that IPR, should they decide to assert the patent. Unified Patents is noted as the petitioner, indicating a defensive aggregator was involved, which often suggests a patent with potential for broader assertion. The patent owner is the Massachusetts Institute of Technology.

Recommended next steps

To understand the full impact of IPR2021-00341 on US9708965, a defendant should:

1. Obtain and thoroughly review the Final Written Decision for IPR2021-00341. This can be done via the Unified Patents portal link provided: https://portal.unifiedpatents.com/ptab/case/IPR2021-00341. The FWD will detail which specific claims (if any) were invalidated and the reasoning behind those decisions.
2. If claims were invalidated, quote the disposition from the FWD directly, as it forms a strong basis for invalidity in district court litigation.
3. Assess the prior art grounds raised in IPR2021-00341 to determine which prior art is now subject to estoppel for the petitioner and its privies. This will inform what prior-art based defenses are still available to a defendant not in privity with Unified Patents.

Inventors

• Leslie Bromberg (Massachusetts Institute of Technology)
• Daniel R. Cohn (Massachusetts Institute of Technology)
• John B. Heywood (Massachusetts Institute of Technology)

No unusual patterns observed regarding inventor departures.

Original assignee

Massachusetts Institute of Technology (MIT). MIT is a research university and typically does not ship products in the commercial sense. Its primary line of business is education and research. MIT is currently operating.

Assignment timeline

There are no assignment records for US patent 9708965 on the USPTO Patent Assignment Search database beyond the initial assignment to Massachusetts Institute of Technology, as indicated by the Google Patents legal events which show "Assigned to MASSACHUSETTS INSTITUTE OF TECHNOLOGY" on 2015-09-08, coinciding with the application filing period.

Timeline diagram

timeline
    title Ownership of US 9708965
    2015 : Application filed by MIT
    2017 : Patent issued to MIT

NPE / troll-pattern signals

1. Shell-entity transfer — not present
2. Known asserter in the chain — not present
3. Repeat correspondent across the chain — not present
4. Cascading transfers — not present
5. Pre-litigation transfer — unclear (litigation is noted, but no preceding assignment is recorded)
6. Bankruptcy fire-sale — not present
7. Privateering — unclear
8. Defensive aggregator (anti-NPE) — not present

Verdict

Insufficient data

There are no recorded assignments for US 9708965 beyond the initial ownership by the Massachusetts Institute of Technology, as confirmed by the USPTO assignment search. While Google Patents indicates litigation associated with this patent, there is no public record of a transfer to an NPE.

USPTO Assignment Center Search for US9708965

Identification of Most Relevant Prior Art for US Patent 9708965

The following prior art references are identified as most relevant based on their direct relationship to the fuel management system, direct injection, and ethanol or anti-knock agent use, as detailed in the description and claims of US9708965. A comprehensive review of all cited patents would be extensive; therefore, the analysis focuses on key preceding patents and those explicitly referenced within the specification of US9708965.

1. U.S. Patent No. 7,314,033 (US7314033B2)

• Full Citation: US7314033B2, "Spark ignition engine with direct injection ethanol enhancement," issued to Bromberg et al. [cite: Prior art date]

• Publication/Filing Date: The filing date of the application leading to US7314033B2 was November 18, 2004 [cite: Priority date]. It was published on January 1, 2008.

• Brief Description: This patent describes a spark ignition engine that achieves high efficiency and power by directly injecting an anti-knock agent, preferably ethanol, into the engine cylinders. The direct injection of ethanol facilitates the use of higher compression ratios and/or increased manifold pressure (turbocharging/supercharging) without engine knock, especially at high loads. The system manages the amount of ethanol injected to control knock and maintain substantially stoichiometric operation. The parent patent (US7314033B2) focuses on the core concept of direct injection of an anti-knock agent to enable higher engine performance.

• Potential Anticipation (35 U.S.C. § 102): US7314033B2, being a parent application, anticipates many fundamental aspects of Claim 1 of US9708965, particularly:

  • A fuel management system for a spark ignition engine.
  • A first fueling system directly injecting fuel (anti-knock agent) into at least one cylinder as a liquid to increase knock suppression by evaporative cooling.
  • A second fueling system injecting fuel (gasoline) into a region outside the cylinder (port injection).
  • A range of torque where both fueling systems are used.
  • The fraction of fuel from the first system increasing with manifold pressure to prevent knock.
  • The use of ethanol as an anti-knock agent.
  • The concept of using a knock sensor to control injection of the anti-knock agent.

  Specifically, the concept of direct injection of an anti-knock agent (ethanol) to enhance knock suppression in a gasoline engine, often with port-injected gasoline, forms the core of both patents. The fuel management aspect to control knock is also present. The main distinctions in US9708965 (Claim 1) appear to be the explicit combination of closed-loop control using a knock sensor and open-loop control using an engine map lookup table, with open-loop being used during transients, which may be a refinement over the parent. The parent patent establishes the fundamental architecture and function.

2. U.S. Patent No. 7,225,787 (US7225787B2)

• Full Citation: US7225787B2, "Direct injection ethanol enhancement of gasoline engines," issued to Bromberg et al. [cite: Priority date]

• Publication/Filing Date: The application leading to US7225787B2 was filed on April 6, 2005 [cite: Priority date], and it was published on June 5, 2007.

• Brief Description: This patent also relates to enhancing gasoline engines through the direct injection of ethanol as an anti-knock agent. It further elaborates on system configurations and operational strategies for managing the dual-fuel system to achieve improved efficiency and power, particularly through higher manifold pressures and compression ratios, while controlling emissions. Like US7314033B2, it details the benefits of ethanol's high heat of vaporization for knock suppression.

• Potential Anticipation (35 U.S.C. § 102): As another parent application, US7225787B2 similarly anticipates many elements of Claim 1 of US9708965. It reinforces the core concepts of:

  • Dual fueling systems (direct injection of anti-knock agent and port injection of gasoline).
  • Utilizing evaporative cooling from direct injection for knock suppression.
  • Varying the proportion of the direct-injected fuel to prevent knock based on engine conditions (implicitly including manifold pressure).
  • The overall fuel management strategy for optimizing engine operation with ethanol.

  Similar to US7314033B2, the specific emphasis in Claim 1 of US9708965 on the combination of closed-loop and open-loop control, and the use of open-loop during transients, might represent an incremental improvement or more explicit detailing over the general control schemes described in US7225787B2.

3. U.S. Patent No. 6,332,448 (US6332448B1)

• Full Citation: US6332448B1, "Fuel supply system for internal combustion engine," issued to Iiyama et al.
• Publication/Filing Date: This patent was filed on September 28, 2000, and published on December 25, 2001.
• Brief Description: This patent describes a fuel supply system for an internal combustion engine, specifically addressing the separation of different fuel components (e.g., gasoline and diesel) onboard a vehicle, often for exhaust aftertreatment purposes. It discusses methods like distillation or absorption/desorption for separating fuel components. US9708965 references this patent when discussing "membrane separation of ethanol from gasoline" as being simpler than "distillation or absorption/desorption approaches (see Ilyama et al, U.S. Pat. No. 6,332,448) that have been suggested for separation of various gasoline/diesel fuels."
• Potential Anticipation (35 U.S.C. § 102): US6332448B1 primarily relates to onboard fuel separation techniques. While it mentions a fuel supply system, its direct relevance to Claim 1 of US9708965 is limited because Claim 1 focuses on the injection and control strategy for dual fuels (direct-injected anti-knock agent and port-injected gasoline) to prevent knock, rather than the onboard separation of fuels. It might anticipate aspects of a broader "fuel management system" if that term were interpreted very broadly to include fuel generation/separation. However, it does not disclose the specific elements of Claim 1, such as direct injection for evaporative cooling, increasing fuel fraction with manifold pressure, or the specific combination of closed-loop and open-loop control for knock prevention. Therefore, it is less likely to anticipate Claim 1 directly, but it provides background art for onboard fuel handling and separation technologies.

4. U.S. Patent No. 6,427,655 (US6427655B1)

• Full Citation: US6427655B1, "Engine with direct fuel injection and port fuel injection," issued to Hitomi et al.

• Publication/Filing Date: This patent was filed on October 25, 2000, and published on August 6, 2002.

• Brief Description: This patent describes an internal combustion engine equipped with both direct fuel injection into the cylinder and port fuel injection into the intake port. The control system adjusts the ratio of direct injection to port injection based on engine operating conditions (e.g., load, speed) to optimize fuel economy, emissions, and power. It discusses injecting fuel at different timings (e.g., during intake stroke or compression stroke) for direct injection and controlling the total fuel amount.

• Potential Anticipation (35 U.S.C. § 102): US6427655B1 is highly relevant as it discloses an engine system with both direct injection and port injection, which is a key structural element of Claim 1. It also discusses controlling the ratio of these injections based on engine conditions. This patent could potentially anticipate:

  • A first fueling system directly injecting fuel into at least one cylinder.
  • A second fueling system injecting fuel into a region outside of the cylinder.
  • A control system for both fueling systems.
  • Varying the fraction of fuel introduced by the first fueling system.

  However, US6427655B1 does not explicitly focus on using a specific anti-knock agent like ethanol for evaporative cooling to achieve increased knock suppression and enable higher manifold pressures, nor does it explicitly detail the combination of closed-loop knock sensor control with open-loop map control during transients for knock prevention as the primary objective. Its primary focus is broader fuel economy and emissions control with dual injection, not necessarily optimized anti-knock agent use for boosting. Therefore, while it establishes the dual-injection architecture, the specific functional and control aspects related to ethanol-enhanced knock suppression in Claim 1 would likely differentiate US9708965.

5. U.S. Patent No. 6,640,791 (US6640791B2)

• Full Citation: US6640791B2, "Method and apparatus for controlling fuel injection for internal combustion engine," issued to Yamamoto et al.

• Publication/Filing Date: This patent was filed on September 28, 2001, and published on November 4, 2003.

• Brief Description: This patent describes a fuel injection control system for an internal combustion engine that uses a direct injector and a port injector. The system controls the injection amount from each injector based on engine load and speed, particularly focusing on optimizing performance and reducing emissions. It also discusses detecting engine knock and adjusting fuel injection to suppress it, and may use an engine map.

• Potential Anticipation (35 U.S.C. § 102): Similar to US6427655B1, US6640791B2 discloses a dual-injection system with control based on engine conditions and includes knock detection and suppression. This patent could potentially anticipate:

  • A first fueling system directly injecting fuel.
  • A second fueling system injecting fuel into a region outside the cylinder.
  • Control of fueling from both systems.
  • The use of a sensor that detects knock for control.
  • The use of an engine map lookup table (open loop control).

  However, like US6427655B1, it does not specifically teach the direct injection of an anti-knock agent with high heat of vaporization (like ethanol) for the explicit purpose of increasing knock suppression by evaporative cooling to permit higher manifold pressures, nor does it detail the specific interplay between closed-loop (knock sensor) and open-loop (map during transients) control for this particular knock-prevention strategy using an anti-knock agent. The emphasis in US9708965 on the chemical properties of the injected fuel (high heat of vaporization) and its specific role in knock resistance, combined with the timing of injection (after inlet valve closure) and the combined control strategy, likely distinguishes it from this general dual-injection control patent.

Obviousness Analysis under 35 U.S.C. § 103 for US Patent 9,708,965

This analysis identifies combinations of prior art references that would render Claim 1 of US Patent 9,708,965 obvious to a person having ordinary skill in the art (PHOSITA) as of the earliest priority date of November 18, 2004.

Person Having Ordinary Skill in the Art (PHOSITA)

A PHOSITA in this field would be an automotive engineer or a researcher with expertise in internal combustion engine design, fuel systems, and electronic engine control strategies, particularly concerning knock mitigation and performance optimization in spark-ignition engines. They would be familiar with direct fuel injection, port fuel injection, turbocharging, and various open-loop and closed-loop control methodologies.

Combinations of Prior Art and Motivation to Combine

The independent Claim 1 of US9708965 describes a fuel management system for a spark ignition engine utilizing both a direct injection (first) fueling system for knock suppression via evaporative cooling and a port injection (second) fueling system. The system employs a control strategy involving both open-loop (map-based, particularly for transients) and closed-loop (knock sensor-based) control, where the fraction of direct-injected fuel increases with manifold pressure to combat knock.

The primary prior art for this analysis is US Patent 7,314,033 B2 (Bromberg et al.), the earliest parent application of US9708965, which has a priority date of November 18, 2004, and is explicitly incorporated by reference into US9708965 [cite: Description]. Additional relevant prior art includes general knowledge of engine control systems and published works such as SAE paper 2003-01-0542 by Lecointe and Monnier, discussing turbocharging with direct injection, and SAE paper 2000-01-2902 by Stokes et al., on lean boost systems and stoichiometric operation.

Combination: US Patent 7,314,033 B2 (Bromberg et al.) + General Knowledge of Engine Control & Turbocharging

US Patent 7,314,033 B2 (Bromberg et al.) explicitly teaches a fuel management system for a spark ignition internal combustion engine that includes:

• Direct injection of a liquid anti-knock agent (such as ethanol) into the cylinder to control knock [cite: Description]. This fulfills the "first fueling system that directly injects fuel into at least one cylinder as a liquid and increases knock suppression by evaporative cooling" aspect of Claim 1. The abstract of US9708965 reinforces this, stating the invention relates to direct injection of an anti-knock agent such as ethanol. [cite: Abstract]
• Separate introduction of a fuel (e.g., gasoline) into the air intake system (port injection) or the cylinder [cite: Description]. This directly addresses the "second fueling system that injects fuel into a region outside of the cylinder" aspect of Claim 1. US9708965 itself confirms this preferred embodiment: "part of the fuel is port injected and the port injected fuel is gasoline." [cite: the engine]
• Controlling the introduction of the anti-knock agent to control knock [cite: Description]. This provides a foundational teaching for the control aspects of Claim 1.

Given the teachings of US7314033B2, a PHOSITA would be motivated to combine these teachings with well-known engine control strategies to further optimize performance and knock suppression.

Specific elements of Claim 1 and their obviousness:

1. "where there is a range of torque where both fueling systems are used at the same value of manifold pressure":

   • Motivation: Engine designers routinely calibrate fuel management systems to operate efficiently across the entire engine map, which includes various torque and manifold pressure conditions. In a dual-fuel system aimed at performance and knock control (as taught by Bromberg et al. US7314033B2), a PHOSITA would naturally optimize the ratio of the two fuels to achieve desired torque at specific manifold pressures while preventing knock. This would inevitably lead to operating ranges where both fuels are utilized at a given manifold pressure to provide varying torque levels or to sustain that manifold pressure under different engine demands.

2. "where a fraction of fuel in the cylinder that is introduced by the first fueling system increases with increasing manifold pressure so as to prevent knock by providing increased knock resistance":

   • Motivation: It is a fundamental understanding in internal combustion engine design that increasing manifold pressure (e.g., through turbocharging, as discussed by Lecointe and Monnier, 2003) significantly increases the engine's propensity for knock. Since US7314033B2 teaches direct injection of an anti-knock agent specifically for knock suppression, a PHOSITA would be logically motivated to increase the amount (fraction) of this knock-suppressing fuel as the knock tendency (driven by higher manifold pressure) rises. The relationship between ethanol fraction and manifold pressure to prevent knock is explicitly shown in FIG. 1 of US9708965 [cite: FIG. 1], illustrating this as an expected and optimal control strategy rather than a non-obvious invention.

3. "where the fuel management system controls the change in the fraction of fuel introduced by the first fueling system using closed loop control that utilizes a sensor that detects knock and where open loop control is also used":

   • Motivation: Knock sensors and closed-loop control systems based on knock detection were standard in gasoline engines well before 2004 for preventing knock, typically by retarding spark timing or adjusting fuel delivery. US9708965 itself states: "The injection of the antiknock agent can be initiated by a signal from a knock sensor." [cite: the injection of the antiknock agent] A PHOSITA, faced with the objective of precisely controlling knock in a direct-injection anti-knock system (as taught by Bromberg et al. US7314033B2), would find it obvious to integrate a known knock-sensing feedback mechanism (closed-loop control) to modulate the delivery of the direct-injected anti-knock fuel. Furthermore, the combination of open-loop and closed-loop control is a conventional and effective approach in engine management systems, allowing for both precise feedback control and stable, predictable operation. US9708965 also states that "The fuel management system may operate in open or closed loop modes." [cite: the fuel management system]

4. "where the open loop control uses an engine map lookup table":

   • Motivation: Engine map lookup tables are a fundamental component of open-loop control in electronic engine control units (ECUs). They store predetermined parameters for fuel injection, ignition timing, and other engine variables across various operating conditions. US9708965 confirms this practice: "open-loop algorithms from a stored engine map (not shown) are used to determine air, gasoline and ethanol flows for keeping substantially stoichiometric combustion in a cylinder of the engine 18." [cite: open-loop algorithms from a stored engine map] A PHOSITA would naturally employ such known techniques in any sophisticated fuel management system.

5. "where open loop control is used during transients in engine load":

   • Motivation: It is a well-established practice in engine control to utilize open-loop, map-based control during transient engine conditions (e.g., rapid acceleration or deceleration) because closed-loop feedback systems can be too slow to react or may introduce instability during rapid changes. This ensures responsiveness and drivability. US9708965 explicitly acknowledges this: "open loop operation during transients may be advantageous." [cite: the fuel management system] A PHOSITA would routinely apply this known control strategy to a dual-fuel system for optimal performance during such conditions.

Conclusion:

Claim 1 of US9708965, as broadly drafted, appears to be an obvious combination of elements taught by its own parent patent, US7314033B2 (Bromberg et al.), and general knowledge readily available to a PHOSITA in the field of engine control and optimization before November 18, 2004. The core concept of a dual-fuel system with direct injection of an anti-knock agent and port injection of gasoline, controlled to prevent knock, is present in US7314033B2. The additional control strategies in Claim 1 (varying anti-knock agent fraction with manifold pressure, closed-loop knock sensing, open-loop map-based control, and specific application during transients) represent predictable applications of well-known engine management techniques to this dual-fuel system. A PHOSITA would be motivated to combine these elements to achieve improved knock suppression, enhanced performance, and robust operation in a turbocharged spark-ignition engine, which were common goals in the automotive industry.