US 7513238

Here is a concise summary of US Patent 7513238, "Directly injecting internal combustion engine," as of April 26, 2026:

Title: Directly injecting internal combustion engine

Current Assignee: Longhorn Automotive Group LLC

Inventors: Ruediger Pfaff, Martin Schnabel, Joachim Suess

Filing Date: October 15, 2004

Issue Date: April 7, 2009

Abstract: A directly injecting internal combustion engine features at least one cylinder with a combustion space where a piston oscillates. It includes an injection nozzle to inject fuel into this space. The piston has a recess in its central region with an elevation pointing towards the cylinder head. A surface of the piston recess, which is adjacent to the elevation and extends towards the recess edge, is connected to the elevation via a radius. This design ensures that an early injection jet impinging on this region is distributed both towards the elevation and the recess edge. Furthermore, this surface has an extent such that a late injection jet also impinges on it and is distributed in both the elevation and recess edge directions.

Plain-Language Overview of Independent Claims:

• Claim 1: This claim describes a directly injecting internal combustion engine. It specifies that the engine has at least one cylinder with a combustion space and an oscillating piston. An injection nozzle introduces fuel into the combustion space. The piston features a recess with a central elevation extending towards the cylinder head. A key aspect is a surface within this piston recess that adjoins the central elevation and extends towards the recess edge. This surface is connected to the elevation by a radius. This specific geometry ensures that fuel injected as early as possible, impacting this surface, is distributed both towards the central elevation and towards the outer recess edge. Additionally, this surface is largely flat and has an upward slope towards the recess edge. This design ensures that even fuel injected as late as possible will still impinge on this surface and be distributed in both the elevation and recess edge directions.

CAFC 2026 Dockets:
A search for US patent 7513238 in the CAFC 2026 dockets did not yield specific case filings for 2026. The information available indicates that there is litigation related to this patent, including an IPR case (IPR2025-01089) filed in 2025 that was not instituted procedurally [cite: Unified Patents_Longhorn Automotive_US7513238B2_12.17.2024]. Multiple US cases have been filed in the Texas Eastern District Court [cite: Unified Patents_Longhorn Automotive_US7513238B2_12.17.2024], but these are not specifically CAFC dockets for 2026. General information regarding CAFC case information is available, but no direct 2026 dockets for 7513238 were found.

US patent 7513238 has been involved in multiple litigation cases. The current assignee, Longhorn Automotive Group LLC, appears to be actively asserting this patent.

Here's a summary of known litigation involving US patent 7513238:

Inter Partes Review (IPR) Case:

• Petitioner: Nissan Motor Co., Ltd.
• Patent Owner: Longhorn Automotive Group LLC
• Jurisdiction: Patent Trial and Appeal Board (PTAB)
• Case Number: IPR2025-01089
• Filing Date: June 3, 2025
• Outcome/Status: Not Instituted - Procedural.

US District Court Cases (Texas Eastern District Court):
Longhorn Automotive Group LLC has filed multiple patent infringement lawsuits in the US District Court for the Eastern District of Texas, asserting US patent 7513238, among others. These cases generally involve automotive manufacturers.

• Plaintiff: Longhorn Automotive Group LLC
• Defendant(s): Volkswagen, Mazda, Mitsubishi Group, Volvo, Hyundai, Kia, and Nissan have been asserted against.
  • Volvo Car Corp. and AB Volvo: Longhorn Automotive Group LLC filed a complaint against Volvo Car Corp. and AB Volvo.
    • Filing Date: July 31, 2024.
    • Allegations: Infringement of US Patent Nos. 8,810,803; 7,987,002; 7,513,238; and 8,265,353, relating to headlights, driver assistance, and remote start technologies.
  • Volvo North America LLC, Mack Trucks Inc., Nova Bus US Inc., and Prevost Car US Inc.: Longhorn Automotive Group LLC filed allegations against these additional Volvo AB units.
    • Filing Date: March 24, 2026.
    • Allegations: Infringement of US Patent Nos. 8,810,803, 7,987,002, 7,513,238, and 8,085,192, over headlights, GPS, and mobile apps.
    • Accused Products: Include VNL 860 and VAH 600 trucks.
• Jurisdiction: US District Court for the Eastern District of Texas.
• Case Numbers: Specific case numbers for all district court filings were not explicitly provided in the search results, but examples of general ongoing litigation in this district are noted.
• Outcome/Status: The Volvo cases were newly filed in 2024 and 2026, and their outcomes are not yet available. Unified Patents reported that prior art has been found on US Patent 7,513,238, which could impact ongoing or future litigation.

Proceedings overview

There is one AIA trial proceeding on file for US Patent 7513238. This proceeding, IPR2025-01089, resulted in a discretionary denial of institution, meaning the PTAB did not proceed to a full review of the patentability of the challenged claims. This outcome suggests that the patent has survived one attempt at IPR, providing a hardened defensive posture against similar challenges from the petitioner and its privies.

IPR2025-01089 — Nissan Motor Co., Ltd. v. Longhorn Automotive Group LLC

• Type: Inter Partes Review
• Filed: 2025-06-03
• Status: Discretionary Denial. The Patent Trial and Appeal Board (PTAB) declined to institute the IPR, meaning the merits of the patentability challenge were not fully adjudicated.
• Judge panel: The specific judge panel for IPR2025-01089 is not publicly detailed in the provided search results. However, as of October 2025, Director John Squires personally decides institution determinations in IPR cases, following consultation with at least three PTAB judges, often issuing summary notices.
• Petition grounds: The specific claims challenged, prior art asserted, and statutory bases (§ 102 / § 103 / § 112) for this IPR are not detailed in the provided search results.
• Institution decision: Denied on 2025-12-03 (last modified date). The decision was a discretionary denial. While specific reasoning for IPR2025-01089 is not detailed in the provided search results, recent discretionary denials by the USPTO Director have often relied on factors such as "settled expectations" of the parties, the length of time claims have been in force, and the petitioner's awareness of the patent, even when other Fintiv factors might favor institution. The Director has also considered the efficient use of Office resources.
• Final Written Decision: Not applicable, as institution was denied.
• Settlement / termination: Not applicable, as institution was denied.
• Appeal: Not applicable, as institution was denied. (Institution decisions are generally barred from appellate review under 35 U.S.C. § 314(d)).
• Defensive value: This proceeding demonstrates that an IPR challenge by Nissan Motor Co., Ltd. was unsuccessful in instituting a trial. This means the claims of US7513238 were not invalidated or confirmed by the PTAB on the merits in this instance. For Nissan (and its privies), estoppel under § 315(e)(2) would likely apply to the grounds raised or that reasonably could have been raised in this petition, making it harder for them to challenge the patent on those same grounds again. For other potential defendants, this IPR attempt's failure suggests the patent owner is capable of successfully arguing against institution, though the specific grounds for denial for this IPR are not publicly detailed here.

Strategic summary

The patent US7513238 has undergone one AIA trial proceeding, IPR2025-01089, which concluded with a discretionary denial of institution. This means that all claims of US7513238 remain untested on the merits by the PTAB, as the Board did not proceed to a full trial. No claims have been canceled or sustained by a Final Written Decision in an IPR.

Regarding the estoppel landscape, Nissan Motor Co., Ltd., as the petitioner in IPR2025-01089, along with its privies, would likely be estopped under 35 U.S.C. § 315(e)(2) from challenging the patent on any grounds that were raised or reasonably could have been raised in their petition. However, for a defendant not in privy with Nissan, all prior-art grounds remain potentially available for a future IPR petition. The specific prior art and claims challenged in IPR2025-01089 are not detailed in the provided information, thus the exact scope of estoppel for Nissan is not fully ascertainable from this data.

The outcome of IPR2025-01089 reflects the USPTO's evolving stance on discretionary denials, particularly policies introduced in 2025. The shift includes the Director's increased personal involvement in institution decisions and the consideration of factors like "settled expectations" and efficiency in workload management. The fact that this IPR was denied on discretionary grounds, rather than on the merits of the invalidity arguments, indicates that procedural or policy considerations played a significant role.

Recommended next steps

For any defendant currently facing assertion of US7513238, the primary takeaway is that the patent's claims have not been challenged on their merits at the PTAB. While one IPR petition was filed, it was denied institution. This means the patent's validity against prior art, as determined by the PTAB, is an open question for any party not subject to estoppel from IPR2025-01089.

Given the discretionary denial, a potential defendant should:

• Thoroughly investigate the specific grounds raised in IPR2025-01089 by Nissan, if that information can be accessed, to understand the scope of potential estoppel for Nissan and its privies.
• Conduct a robust prior art search and analysis to identify strong unpatentability grounds (anticipation under § 102 or obviousness under § 103) against the asserted claims of US7513238.
• Carefully consider the USPTO's current discretionary denial framework, particularly the "settled expectations" factor and the Director's active role in institution decisions, when preparing any new IPR petition. The longer a patent has been in force, the more significant this factor may become.
• If considering a new IPR, focus on presenting compelling evidence of unpatentability and providing persuasive reasoning why an IPR is an appropriate use of Office resources, addressing the Director's current discretionary considerations.

Inventors

• Ruediger Pfaff (Daimler AG)
• Martin Schnabel (Daimler AG)
• Joachim Suess (Daimler AG)

Original assignee

The original assignee on the issued patent was Daimler AG. Daimler AG is a German multinational automotive company that designs, manufactures, and sells a wide range of vehicles, including passenger cars (under the Mercedes-Benz brand), trucks, and vans. The company has a history of producing diesel engines and directly injecting internal combustion engines, which aligns with the technology of US7513238. Daimler AG was renamed Mercedes-Benz Group AG in February 2022 to reflect its focus on luxury passenger vehicles. The company is currently operating.

Assignment timeline

• 2007-03-27 (executed) / recorded 2007-03-27 — Reel 019124/0896
  • Conveyance: Assignment
  • Assignor: Ruediger Pfaff, Martin Schnabel, Joachim Suess
  • Assignee: DAIMLERCHRYSLER AG
  • Correspondent: N/A (inventor assignment)
  • Context: Internal reorg/initial assignment from inventors to company
• 2008-05-14 (executed) / recorded 2008-05-14 — Reel 020976/0889
  • Conveyance: Change of Name
  • Assignor: DAIMLERCHRYSLER AG
  • Assignee: DAIMLER AG
  • Correspondent: N/A
  • Context: Corporate name change from DaimlerChrysler AG to Daimler AG.
• 2012-01-31 (executed) / recorded 2012-01-31 — Reel 027624/0585
  • Conveyance: Assignment
  • Assignor: DAIMLER AG
  • Assignee: BURANI CONSULTING LIMITED LIABILITY COMPANY
  • Correspondent: N/A
  • Context: Transfer to an unknown entity.
• 2015-12-11 (executed) / recorded 2015-12-11 — Reel 037273/0458
  • Conveyance: Merger
  • Assignor: BURANI CONSULTING LIMITED LIABILITY COMPANY
  • Assignee: CHEMTRON RESEARCH LLC
  • Correspondent: N/A
  • Context: Merger of Burani Consulting into Chemtron Research LLC.
• 2020-07-01 (executed) / recorded 2020-07-01 — Reel 053583/0493
  • Conveyance: Corrective Assignment
  • Assignor: DAIMLERCHRYSLER AG
  • Assignee: DAIMLER AG
  • Correspondent: N/A
  • Context: Corrective assignment to update the application number, confirming a change of name.
• 2023-09-25 (executed) / recorded 2023-09-25 — Reel 065015/0641
  • Conveyance: Assignment
  • Assignor: CHEMTRON RESEARCH LLC
  • Assignee: INTELLECTUAL VENTURES ASSETS 190 LLC
  • Correspondent: Robert A. Parsons, INTELLECTUAL VENTURES MANAGEMENT, LLC, 2800 156TH AVE SE, BELLEVUE, WA, UNITED STATES, 98007. This correspondent also appears in other tracked patent assignments.
  • Context: Transfer to a known patent asserter.
• 2023-10-13 (executed) / recorded 2023-10-13 — Reel 065227/0107
  • Conveyance: Assignment
  • Assignor: INTELLECTUAL VENTURES ASSETS 190 LLC
  • Assignee: AI-CORE TECHNOLOGIES, LLC
  • Correspondent: N/A
  • Context: Transfer from a known patent asserter to another entity.
• 2024-03-26 (executed) / recorded 2024-03-26 — Reel 066911/0261
  • Conveyance: Assignment
  • Assignor: AI-CORE TECHNOLOGIES, LLC
  • Assignee: LONGHORN AUTOMOTIVE GROUP LLC
  • Correspondent: Michael J. Mondelli, MANDELI LAW PLLC, 3500 Maple Ave Ste 1200, Dallas, TX, UNITED STATES, 75219. This correspondent also appears in other tracked patent assignments.
  • Context: Transfer to the current asserting entity.

Timeline diagram

timeline
    title Ownership of US 7513238
    2007 : Assigned to DAIMLERCHRYSLER AG
    2008 : Name change to DAIMLER AG
    2012 : Assigned to BURANI CONSULTING LLC
    2015 : Merged to CHEMTRON RESEARCH LLC
    2020 : Corrective assignment to DAIMLER AG
    2023 : Assigned to INTELLECTUAL VENTURES ASSETS 190 LLC
         : Assigned to AI-CORE TECHNOLOGIES LLC
    2024 : Assigned to LONGHORN AUTOMOTIVE GROUP LLC

NPE / troll-pattern signals

1. Shell-entity transfer — present. The patent moved from an operating company (Daimler AG) to BURANI CONSULTING LIMITED LIABILITY COMPANY (Reel 027624/0585), then to CHEMTRON RESEARCH LLC (Reel 037273/0458), then to INTELLECTUAL VENTURES ASSETS 190 LLC (Reel 065015/0641), then to AI-CORE TECHNOLOGIES, LLC (Reel 065227/0107), and finally to LONGHORN AUTOMOTIVE GROUP LLC (Reel 066911/0261). While some intermediate entities have generic names, Intellectual Ventures is a known patent licensing entity. AI-CORE TECHNOLOGIES, LLC appears to be an AI products and services company, but its involvement in this chain for an internal combustion engine patent suggests a portfolio acquisition rather than product development. Longhorn Automotive Group LLC appears to be a used car dealership based on online search results, which is inconsistent with developing or implementing internal combustion engine technology itself.
2. Known asserter in the chain — present. INTELLECTUAL VENTURES ASSETS 190 LLC is part of Intellectual Ventures, a well-known patent licensing and assertion entity. This is evidenced by the assignment on Reel 065015/0641, executed and recorded on 2023-09-25. Longhorn Automotive Group LLC is also actively asserting this patent in district court cases against various automotive manufacturers.
3. Repeat correspondent across the chain — present. Robert A. Parsons of INTELLECTUAL VENTURES MANAGEMENT, LLC is listed as the correspondent for the assignment to INTELLECTUAL VENTURES ASSETS 190 LLC (Reel 065015/0641). Michael J. Mondelli of MANDELI LAW PLLC is listed as the correspondent for the assignment to LONGHORN AUTOMOTIVE GROUP LLC (Reel 066911/0261). This firm also represents Longhorn Automotive Group LLC in litigation. The presence of these specific attorneys, particularly Michael J. Mondelli, acting for sequential assignees or related litigation, is a strong indicator of a coordinated assertion strategy.
4. Cascading transfers — present. There are several rapid transfers: from CHEMTRON RESEARCH LLC to INTELLECTUAL VENTURES ASSETS 190 LLC (2023-09-25, Reel 065015/0641), then to AI-CORE TECHNOLOGIES, LLC (2023-10-13, Reel 065227/0107), and then to LONGHORN AUTOMOTIVE GROUP LLC (2024-03-26, Reel 066911/0261). These transfers occurred within a span of approximately six months.
5. Pre-litigation transfer — present. The patent was assigned to Longhorn Automotive Group LLC on March 26, 2024 (Reel 066911/0261). Longhorn Automotive Group LLC filed a complaint against Volvo Car Corp. and AB Volvo on July 31, 2024, within six months of the assignment. This pattern suggests the transfer was arranged to enable assertion.
6. Bankruptcy fire-sale — not present. Daimler AG (now Mercedes-Benz Group AG) is a large, operating automotive company and has not undergone a bankruptcy fire-sale related to this patent.
7. Privateering — unclear. While the original operating company (Daimler AG) transferred the patent, there is no explicit evidence from the provided data that Daimler AG is acting through Longhorn Automotive Group LLC to assert against competitors.
8. Defensive aggregator (anti-NPE) — not present. The chain does not end at a known defensive aggregator like RPX, Allied Security Trust (AST), LOT Network, Unified Patents, or Open Invention Network.

Verdict

NPE — high confidence

This verdict is based on several strong signals: the transfer of the patent from an operating company (Daimler AG) through multiple entities including a known patent asserter (Intellectual Ventures Assets 190 LLC) and shell-like entities (BURANI CONSULTING LIMITED LIABILITY COMPANY, CHEMTRON RESEARCH LLC, AI-CORE TECHNOLOGIES, LLC), culminating in its ownership by Longhorn Automotive Group LLC which appears to be a used car dealership, not a developer of internal combustion engine technology. The rapid, cascading transfers within a short period (Reel 065015/0641, Reel 065227/0107, Reel 066911/0261), coupled with the pre-litigation transfer (Reel 066911/0261) directly preceding numerous infringement lawsuits, strongly indicate an assertion-driven strategy. The recurrence of specific correspondent attorneys also supports this conclusion.

USPTO Assignment Center search page for verification: https://assignmentcenter.uspto.gov/

To identify the most relevant prior art for US patent 7513238, I will examine the patent citations listed within the patent itself and leverage information regarding prior art identified in recent litigation.

Based on the provided information, here are some of the most relevant prior art references for US patent 7513238:

1. US 2002/0117146 A1 (Bertrand Gatellier)

• Full Citation: US20020117146A1.
• Publication/Filing Date: Publication date: 2002-08-29. Filing date: 2000-12-20.
• Brief Description: This patent describes a direct-injection engine with a relatively steep injection angle into the combustion space, where the piston recess is at least partially adapted to the injection angle. The '238 patent itself mentions this reference in its background, stating that "as steep an injection angle as possible at the injection nozzle should be selected... This also requires the shape of the piston recess to be adapted to this injection, as is the case, for example, in US 2002/0117146 A1".
• Potential Anticipated Claim(s) under 35 U.S.C. § 102: The adaptation of the piston recess to a steep injection angle, which is a foundational aspect of claim 1, could be anticipated. Specifically, the concept of a piston recess designed to interact with a direct injection jet.

2. DE 196 49 052 A1 (Mtu Friedrichshafen Gmbh)

• Full Citation: DE19649052A1.
• Publication/Filing Date: Publication date: 1998-05-28. Filing date: 1996-11-27.
• Brief Description: This reference also describes a special shape of the piston recess provided to reduce pollutants in a diesel engine with direct injection.
• Potential Anticipated Claim(s) under 35 U.S.C. § 102: Similar to US 2002/0117146 A1, the general concept of a specially shaped piston recess in a direct injection diesel engine for improved operation could be anticipated.

3. US 5,868,112 (Cummins)

• Full Citation: US5868112A.
• Publication/Filing Date: Publication date: 2000-12-19. Filing date: 1998-03-27.
• Brief Description: This patent describes a method for creating an internal combustion piston with a combustion bowl designed to reduce soot and promote efficient air/fuel mixing through a toroidal flow pattern. The combustion bowl has a large-radius floor and a smaller-radius outer section and guides the fuel spray away from cylinder walls towards the cylinder head for better mixing. This reference has been identified as a "winning submission" for prior art against US7513238 in a Unified Patents contest.
• Potential Anticipated Claim(s) under 35 U.S.C. § 102: Claim 1 of US7513238 describes a piston recess with an elevation and a surface connected via a radius, designed to distribute injection jets. The description of the Cummins patent's combustion bowl with specific radii and its function in fuel distribution and air/fuel mixing strongly suggests it could anticipate elements of claim 1, particularly the shape and function of the piston recess in directing the fuel.

4. US 6,378,486 (Volkswagen)

• Full Citation: US6378486A.
• Publication/Filing Date: Publication date: 2002-04-30. Filing date: 1999-05-14.
• Brief Description: This patent details a four-stroke, spark-ignition internal combustion engine with direct fuel injection. It includes a combustion space, an injection nozzle, and a piston with a recess divided by an elevation into a fuel recess and an air recess. This reference has also been identified as a "winning submission" for prior art against US7513238 in a Unified Patents contest.
• Potential Anticipated Claim(s) under 35 U.S.C. § 102: Claim 1 of US7513238 describes a piston recess with a central elevation. The Volkswagen patent's description of a piston with a recess divided by an elevation directly anticipates this feature of claim 1.

5. US 2005/0229897 A1

• Full Citation: US20050229897A1.
• Publication/Filing Date: Publication date: 2005-10-20. Filing date: 2004-04-14.
• Brief Description: While the initial search results indicated that US patent 7513238 pertains to directly injecting internal combustion engines, some search results from Unified Patents identify US 2005/0229897 as prior art related to "wireless communication technology". This creates a direct contradiction with the provided patent summary which clearly states the patent is for an internal combustion engine. Given the explicit title of US7513238 ("Directly injecting internal combustion engine") and the detailed description of the combustion engine components in the patent text, the characterization of US 2005/0229897 as prior art for a "wireless communication technology" for US7513238 is likely an error in the Unified Patents' record or context. Therefore, further analysis of US 2005/0229897 as prior art for internal combustion engines is needed for a comprehensive assessment, and without specific details on its relation to internal combustion engines, its relevance to the claims of US7513238 under 35 U.S.C. § 102 cannot be determined from the provided information.

General Note on Anticipation (35 U.S.C. § 102):
For a prior art reference to anticipate a claim under 35 U.S.C. § 102, it must disclose every element of the claimed invention, either explicitly or inherently, such that a person of ordinary skill in the art could practice the invention from the single prior art reference. The filing date of US 7513238 is October 15, 2004, with a priority date of October 29, 2003. Therefore, any reference publicly available before these dates could potentially be anticipatory.

Obviousness Analysis under 35 U.S.C. § 103

A patent claim is considered obvious under 35 U.S.C. § 103 if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art (PHOSITA). A PHOSITA is a hypothetical person who possesses ordinary skill, ordinary creativity, and ordinary knowledge in the relevant technical field at the time of the invention. The motivation to combine prior art references can come from various sources, including the knowledge of those skilled in the art, the nature of the problem to be solved, or the interrelated teachings of the references themselves. It's important to note that merely identifying each claim element in the prior art is insufficient; a reason for combining them must exist.

The earliest priority date for US Patent 7513238 is October 29, 2003. Therefore, the obviousness analysis considers what would have been obvious to a PHOSITA in the field of internal combustion engines prior to this date.

Definition of a PHOSITA in this Field

For an internal combustion engine, a PHOSITA would likely be a mechanical engineer or technician with practical experience in engine design, particularly with direct injection systems. This individual would be familiar with conventional wisdom, standard design choices, and routine experimentation in the field, capable of combining known elements to solve common engine performance and emissions problems. They would also have a general understanding of the scientific and engineering principles of combustion, fuel injection, and piston design in internal combustion engines.

Obviousness Combinations

Claim 1 of US 7513238 describes a direct-injection internal combustion engine with a piston having a recess with a central elevation. A surface adjoining this elevation towards the recess edge is connected via a radius, ensuring early injection jets are distributed in both elevation and recess edge directions. This surface is substantially planar with an ascending gradient towards the recess edge, ensuring late injection jets also impinge and distribute in both directions. The core innovation lies in the specific geometry of the piston recess to optimize fuel distribution for both early and late injection timings.

Below are combinations of prior art references that could render Claim 1, and subsequently its dependent claims, obvious to a PHOSITA.

Combination 1: US 2002/0117146 A1 in view of DE 196 49 052 A1 and general knowledge in the art.

• US 2002/0117146 A1 (Gatellier): This reference describes a direct-injection engine where fuel is injected at a relatively steep angle into the combustion space, and the piston recess is at least partially adapted to the injection angle. Gatellier aims to improve mixture formation and reduce emissions. It discusses early injection to achieve homogeneous combustion and the need to adapt the piston recess to a steep injection angle to prevent impingement on cylinder walls and ensure a long free jet length.
• DE 196 49 052 A1 (MTU Friedrichshafen GmbH): This patent describes a special shape of the piston recess to achieve an additional reduction in pollutants emitted by the internal combustion engine. While not explicitly detailing the surface geometry of 7513238, it clearly establishes the prior art concept of optimizing piston recess shapes for emission reduction in diesel engines.
• Motivation to Combine: A PHOSITA, seeking to improve the efficiency and reduce emissions in a direct-injection engine, as addressed by Gatellier, would consider combining Gatellier's teachings with the general understanding of piston recess optimization for emission reduction, as highlighted by DE 196 49 052 A1. The problem of effectively mixing fuel with air at different injection timings, while minimizing black smoke, is a known challenge in direct injection engines.
  • Gatellier teaches adapting the piston recess to the injection angle for early, deep penetration of fuel. However, it does not explicitly detail a surface that handles both early and late injections with optimal distribution.
  • A PHOSITA would understand that achieving both homogeneous and conventional combustion processes requires accommodating different injection timings. The existing problem in the prior art, as stated in US 7513238, is that known solutions do not easily allow for both homogeneous and conventional mixture formation across the entire engine characteristic map.
  • To address this, a PHOSITA would be motivated to modify the piston recess of Gatellier, drawing upon the general knowledge of piston recess optimization from DE 196 49 052 A1, to ensure effective distribution of fuel for both early and late injection timings. Specifically, creating a surface connected via a radius to the central elevation would be a predictable modification to guide the fuel, and designing this surface to be substantially planar with an ascending gradient would be a logical step to control the impingement and distribution of both early and late injection jets, thereby maintaining momentum and reducing black smoke, as highlighted in US 7513238 as a problem to be solved.

Combination 2: US 6,161,518 A in view of US 2002/0117146 A1 and EP 1,291,516 A2

• US 6,161,518 A (Kabushiki Kaisha Toyota Chuo Kenkyusho): This patent describes a direct-injection diesel engine and a combustion method aimed at reducing emissions. It focuses on controlling the fuel spray and air flow within the combustion chamber.
• US 2002/0117146 A1 (Gatellier): As discussed above, Gatellier teaches adapting the piston recess to a steep injection angle to ensure a long free jet length for early injections.
• EP 1,291,516 A2 (Isuzu Motors Limited): This reference also describes a direct injection diesel engine. While specific details of piston recess geometry are not exhaustively provided in the snippet, Isuzu is a known manufacturer of diesel engines, including direct injection types, and has focused on improving engine efficiency and reducing toxic emissions. EP 1,291,516 A2, in the broader context of Isuzu's work, would represent efforts to optimize combustion processes in such engines.
• Motivation to Combine: A PHOSITA would be motivated to combine the teachings of these references to achieve a direct-injection engine capable of optimal mixture formation under various operating conditions.
  • US 6,161,518 A addresses the general problem of reducing emissions through controlling fuel spray and air flow.
  • Gatellier provides a specific teaching on adapting the piston recess to the injection angle for early injections.
  • The problem faced by the inventors of US 7513238 was designing a piston recess that works for both homogeneous (early injection) and conventional (later injection) combustion processes.
  • A PHOSITA, considering the goal of reducing emissions (US 6,161,518 A) and the known technique of adapting the piston recess for early injection (Gatellier), and understanding that different injection timings are necessary for different combustion modes (general knowledge in the art of diesel engines, as also addressed by Isuzu in EP 1,291,516 A2), would be motivated to create a piston recess that effectively manages fuel distribution for a range of injection timings.
  • The specific design of Claim 1, with a surface adjoining an elevation via a radius, and having an ascending planar gradient, would be an obvious modification to the piston recess taught by Gatellier, in order to address the challenge of distributing both early and late injection jets effectively. This modification would be aimed at improving air/fuel mixing, reducing black smoke, and enabling operation across a wider characteristic map, which are common goals in diesel engine development.

Combination 3: US 7,156,069 B2 in view of US 2003/0217732 A1 and the need for flexible combustion strategies.

• US 7,156,069 B2 (Komatsu Ltd.): This patent describes a direct injection diesel engine. Komatsu is a prominent manufacturer of heavy-duty diesel engines and has a long history of developing engines with low fuel consumption and low emissions, often through various design features like piston and intake port arrangements. Thus, US 7,156,069 B2 would represent prior art focused on efficient direct injection diesel engine design.
• US 2003/0217732 A1 (Kataoka): This publication describes a combustion control apparatus for a diesel engine. Combustion control in diesel engines often involves managing injection timing and fuel spray characteristics to optimize efficiency and emissions.
• Motivation to Combine: A PHOSITA, seeking to improve the versatility and performance of direct-injection diesel engines, would be motivated to combine the structural features of a Komatsu engine (US 7,156,069 B2) with advanced combustion control strategies (US 2003/0217732 A1).
  • The problem of operating an internal combustion engine with both homogeneous and conventional combustion processes, and adapting the piston recess for both early and late injections, was a known challenge. Diesel engines often employ different combustion modes, such as conventional and premixed compression ignition (PCI), which involve different fuel injection timings.
  • A PHOSITA would recognize that to enable such flexible combustion strategies, the piston recess design must be compatible with both early (homogeneous-like) and late (conventional-like) fuel injections.
  • Given the general understanding of piston recess design for efficient combustion in Komatsu's engines (US 7,156,069 B2) and the focus on combustion control (US 2003/0217732 A1), a PHOSITA would find it obvious to modify the piston recess to effectively distribute fuel for varied injection timings. The specific geometry of Claim 1, with an elevation, a radiused connection to an adjoining surface, and an ascending planar gradient, would be a predictable design choice for a PHOSITA to ensure that the fuel jet's momentum is maintained and distributed optimally for both early and late injections, thereby achieving the desired dual-mode combustion capability. This would be a suitable option to address the problem of adapting to different combustion modes.

In summary, the specific piston recess geometry of Claim 1 of US 7513238, while presenting a detailed solution, appears to be an obvious combination of existing prior art teachings and widely recognized problems in the field of direct-injection internal combustion engines. A PHOSITA, driven by the known needs to improve fuel-air mixing, reduce emissions, and enable flexible combustion strategies across an engine's operating range, would have been motivated to combine the elements described above to arrive at the claimed invention.

US Patent 7513238, titled "Directly injecting internal combustion engine," has an earliest priority date of October 29, 2003, and was filed on October 15, 2004. It was issued on April 7, 2009.

Patent Term Adjustments (PTA) and Patent Term Extensions (PTE):

• Patent Term Adjustments (PTA): PTA can be granted to a patent to compensate for delays incurred by the USPTO during the prosecution of a patent application. This includes delays such as failing to issue a first office action within 14 months of filing, failing to issue an action within four months of an applicant's response, or failing to issue the patent within four months of the issue fee payment. While the provided information states that the patent term "expires 2025-02-07" under "Adjusted expiration" and "Expired - Lifetime" as of 2025-02-07, it does not explicitly detail the calculation or specific amount of any PTA for US7513238. However, given the "Adjusted expiration" date, it is likely that some PTA was applied to extend the term beyond the standard 20 years from its earliest priority date.
• Patent Term Extensions (PTE): PTE is available for patents covering certain products, primarily pharmaceuticals, medical devices, food additives, and animal drugs, to restore patent term lost due to regulatory review periods before commercial marketing. Since US7513238 relates to an internal combustion engine, it is not the type of patent eligible for PTE under 35 U.S.C. § 156.

Continuation and Divisional Applications:

• The provided patent text does not explicitly list any continuation or divisional applications for US7513238.
• Generally, a continuation application allows an applicant to pursue new claims based on the same disclosure as a previously filed "parent" application, sharing the same priority date.
• A divisional application is filed when an applicant wants to pursue claims to a distinct invention that was originally part of a broader "parent" application, often when the USPTO determines that the original application contained more than one invention.

Related Family Members:

The patent text references several related documents:

• Priority Claims: US7513238 claims priority to German patent document DE 103 50 795.7, filed October 29, 2003, and is a National Phase of PCT/EP2004/011637, filed October 15, 2004.
• Other Publications in the Family: US20070193556A1 is listed as another version of the patent.
• Cited Prior Art: The patent cites several prior art documents, including US 2002/0117146 A1 and DE 196 49 052 A1. These are prior art, not typically considered "family members" in the sense of continuations or divisionals.

Projected Expiration Date:

The Google Patents information for US7513238 indicates that its "Legal status" is "Expired - Lifetime," with an "Adjusted expiration" date of February 7, 2025. This suggests the patent has already expired.

For patents filed on or after June 8, 1995, the patent term is generally 20 years from the earliest filing date of the application in its family, plus any Patent Term Adjustment (PTA). The filing date for US7513238 was October 15, 2004, and its earliest priority date was October 29, 2003. A standard 20-year term from the earliest priority date (October 29, 2003) would be October 29, 2023. The "Adjusted expiration" of February 7, 2025, indicates that approximately 1 year and 3 months of PTA were granted.

Defensive Disclosure Document for US Patent 7513238

Patent Title: Directly injecting internal combustion engine
Current Date: April 26, 2026

This document presents a series of derivative variations and combination prior art scenarios for US Patent 7513238, "Directly injecting internal combustion engine." The objective is to proactively establish prior art that renders future incremental improvements or obvious variations in this technical domain non-novel or obvious, thereby limiting potential patentability for competitors. The focus is on expanding the technical disclosure beyond the explicit scope of the granted claims, particularly Claim 1, by exploring alternative materials, operational parameters, cross-domain applications, integration with emerging technologies, and inverse/failure modes.

---

Derivative Variations

1. Material & Component Substitution

Derivative 1.1: Functionally Graded Piston with Ceramic Recess Liner

Enabling Description:
This derivative envisions a directly injecting internal combustion engine wherein the piston (6) is fabricated using functionally graded materials (FGMs), specifically a graded transition from an aluminum-silicon alloy base to a high-temperature resistant ceramic-matrix composite (CMC) layer at the piston crown (adjacent to the combustion space 5). The piston recess (10) itself, including the central elevation (11) and the adjoining planar surface (13), is further coated or lined with a dense, plasma-sprayed zirconia (ZrO2) ceramic. This ceramic liner provides enhanced thermal insulation and wear resistance, allowing for higher combustion temperatures and reducing heat transfer to the piston body. The radius (14) connecting the elevation (11) to the adjoining surface (13) is precisely machined into the ceramic liner to maintain the fuel jet (9) distribution characteristics, even under extreme thermal cycling. The FGM structure is achieved via advanced additive manufacturing techniques like selective laser melting (SLM) for the metallic base and subsequent directed energy deposition (DED) for the ceramic-rich crown, ensuring a robust metallurgical bond and thermal gradient management.

classDiagram
    class Engine {
        +Cylinder
        +CombustionSpace
        +InjectionNozzle
    }
    class Piston {
        +FGM_Structure
        +Recess(CeramicLiner)
    }
    class InjectionNozzle {
        +FuelInjection
    }
    Piston --> Engine : OscillatesIn
    Engine --> Piston : Contains
    Piston --* InjectionNozzle : InteractsWith
    Piston : PistonRecess(10)
    Piston : Elevation(11)
    Piston : Surface(13)
    Piston : Radius(14)
    PistonRecess "1" *-- "1" CeramicLiner : lined with
    CeramicLiner : Zirconia (ZrO2)
    Piston "1" *-- "1" FGM_Structure : composed of
    FGM_Structure : Al-Si to CMC gradient

Derivative 1.2: Piezoelectric Multi-Orifice Nozzle with Variable Spray Angle

Enabling Description:
This variation features a directly injecting internal combustion engine equipped with a piezoelectric multi-orifice injection nozzle (7). Instead of fixed orifices (8), the nozzle incorporates an array of independently actuatable micro-piezoelectric elements, each controlling a sub-millimeter orifice. This allows for dynamic, real-time adjustment of the overall injection angle (α), fuel pressure, and spray pattern (e.g., number of active orifices, individual jet penetration). The piston recess (10) geometry, including the elevation (11) and the connecting radius (14) to the planar surface (13), is designed to optimally interact with this variable spray. For instance, an early injection jet (9a) might utilize a wider spray angle (up to 120°) to ensure impingement on the radius (14) and broad distribution, while a late injection jet (9b) could employ a narrower, more penetrating spray (down to 50°) to precisely target the planar surface (13) with its ascending gradient. The piezoelectric actuators allow for injection events with sub-millisecond precision, enabling highly flexible fuel-air mixing strategies to adapt to varying engine loads and speeds.

flowchart TD
    A[Engine Control Unit (ECU)] --> B{Piezoelectric Injection Nozzle}
    B -- Controls --> C[Multiple Micro-Orifices]
    C -- Delivers --> D(Injection Jet)
    D --> E[Piston Recess]
    E -- Distributes Fuel --> F[Elevation Direction]
    E -- Distributes Fuel --> G[Recess Edge Direction]
    B -- Adjusts --> H{Spray Angle & Pattern}
    H -- Adapts To --> I[Engine Load/Speed]
    E -- Geometry Includes --> J[Central Elevation (11)]
    E -- Geometry Includes --> K[Surface with Radius (13, 14)]

2. Operational Parameter Expansion

Derivative 2.1: Micro-Scale Engine for Portable Power Generation

Enabling Description:
This derivative scales down the directly injecting internal combustion engine to a micro-scale, suitable for portable power generation or micro-UAV propulsion. The single cylinder has a bore diameter in the range of 1-5 mm, and the piston (6) executes an oscillating movement at extremely high frequencies (e.g., 50,000-200,000 RPM). The piston recess (10), elevation (11), and adjoining surface (13) with its radius (14) are fabricated using MEMS (Micro-Electro-Mechanical Systems) techniques, possibly from silicon or silicon carbide. The fuel injection nozzle (7) is a micro-injector, potentially utilizing electrostatic or thermal inkjet principles to deliver pico-liter quantities of fuel (e.g., hydrogen, methanol) with sub-microsecond precision. The small dimensions necessitate precise control over surface tension effects and laminar/turbulent flow transitions within the combustion space (5). The primary function of distributing early and late injection jets is maintained, but the characteristic lengths and timescales are reduced by several orders of magnitude, requiring novel approaches to mixture formation and ignition in such confined volumes.

graph TD
    A[Micro-Engine System] --> B[Micro-Cylinder (1-5mm bore)]
    B --> C[Micro-Piston (6)]
    C --> D[Micro-Piston Recess (10)]
    D -- Includes --> E[Micro-Elevation (11)]
    D -- Includes --> F[Micro-Surface (13)]
    F -- Connected Via --> G[Micro-Radius (14)]
    B --> H[Micro-Injection Nozzle (7)]
    H -- Injects Pico-liter Fuel --> I[Micro-Combustion Space (5)]
    I -- Forms --> J[Micro-Injection Jet (9)]
    J --> D
    C -- Operates At --> K[High Frequencies (50-200k RPM)]
    A -- Fabrication Using --> L[MEMS Techniques]

Derivative 2.2: Ultra-High Pressure Combustion with Adaptive Recess Geometry

Enabling Description:
This derivative explores the directly injecting internal combustion engine operating at ultra-high peak combustion pressures, potentially exceeding 300 bar, characteristic of advanced diesel or homogeneous charge compression ignition (HCCI) concepts. To manage these extreme pressures and ensure optimal fuel-air mixing, the piston recess (10) features an adaptive geometry. The central elevation (11) and/or the planar surface (13) are equipped with embedded, hydraulically or electromagnetically actuated micro-elements capable of dynamically altering their shape or position during the compression and combustion strokes. For example, the elevation (11) could retract slightly during late injection to modify the impingement angle for the jet (9b), or the radius (14) could expand to adjust the deflection of early jets (9a). These actuators are controlled by a high-speed engine management system that receives feedback from in-cylinder pressure and temperature sensors, allowing for real-time optimization of combustion characteristics under varying load conditions. The piston itself is constructed from high-strength superalloys (e.g., Inconel) or high-strength steel to withstand the immense forces.

stateDiagram-v2
    state "Engine_Start" as Start
    state "Compression_Stroke" as Comp
    state "Fuel_Injection" as Inject
    state "Combustion_Event" as Combust
    state "Adaptive_Recess_Adjustment" as Adapt
    state "Feedback_Loop" as Feedback
    state "Optimized_Combustion" as OptCombust

    Start --> Comp : Engine initiated
    Comp --> Inject : TDC approach
    Inject --> Combust : Ignition
    Inject --> Adapt : Simultaneous adjustment
    Combust --> Feedback : Sensors detect P, T
    Feedback --> Adapt : ECU commands adjustments
    Adapt --> Inject : Adjusts for next cycle
    Combust --> OptCombust : Achieves desired outcome

    Adapt --> RecessElevationAdj[Adjust Elevation (11)]
    Adapt --> RecessSurfaceAdj[Adjust Surface (13)/Radius (14)]
    RecessElevationAdj --> Actuators[Hydraulic/Electromagnetic Actuators]
    RecessSurfaceAdj --> Actuators
    Actuators --> PistonRecess[Piston Recess Geometry]

3. Cross-Domain Application

Derivative 3.1: Fuel Injection in a Continuous Flow Chemical Reactor

Enabling Description:
Applying the principles of US7513238 to a continuous flow chemical reactor, the "combustion space" (5) becomes the reaction chamber, and the "piston recess" (10) is a stationary or rotating internal baffle or flow guide within the reactor. A "reactant injection nozzle" (7) introduces a precise stream of reactant 'A' (analogous to fuel) into the reaction chamber. The baffle's geometry includes a central "impingement elevation" (11) and an "adjoining distribution surface" (13) connected by a "flow redirection radius" (14). This design ensures that an early reactant jet (e.g., a liquid or gas stream with high momentum) impinges on the surface via the radius, distributing reactant 'A' both towards the elevation (promoting localized mixing or reaction) and towards the edge of the baffle (facilitating wider dispersion and mixing with other reactants in the main flow). A later reactant jet, or one with lower momentum, impacts the planar surface, ensuring its distribution and preventing a direct, unmixed stream. This optimizes reactant mixing, controls reaction kinetics, and prevents localized hot spots or incomplete reactions. This could be used for catalytic processes, polymerization, or emulsification.

flowchart LR
    A[Reactant 'A' Supply] --> B(Reactant Injection Nozzle)
    B -- Injects Jet --> C[Chemical Reactor Chamber]
    C --> D[Internal Baffle / Flow Guide]
    D -- Geometry: --> E[Central Impingement Elevation (11)]
    D -- Geometry: --> F[Adjoining Distribution Surface (13)]
    F -- Connected by --> G[Flow Redirection Radius (14)]
    B -- Early Jet --> F
    B -- Late Jet --> F
    F -- Distributes Reactant 'A' --> H[Localized Mixing (Elevation Direction)]
    F -- Distributes Reactant 'A' --> I[Wider Dispersion (Baffle Edge Direction)]
    H & I --> J[Optimized Reaction Kinetics]

Derivative 3.2: Particulate Dispersion System for Pharmaceutical Manufacturing

Enabling Description:
In pharmaceutical manufacturing, the controlled dispersion of active pharmaceutical ingredients (APIs) or excipients into a carrier gas or liquid stream is critical. This derivative utilizes the piston recess geometry for a particulate dispersion system. The "cylinder" is a mixing chamber, and the "piston" is a stationary or vibrating dispersion element. The "injection nozzle" (7) delivers a stream of fine pharmaceutical powder (e.g., micronized drug particles) or a liquid suspension. The "dispersion element" has a central "deflection cone" (11) and an "impingement surface" (13) connected by a "scattering radius" (14). An early, high-momentum particulate stream (9a) impinges on the scattering radius (14), causing it to be distributed both towards the apex of the cone (facilitating agglomerate breakup) and towards the outer edge of the impingement surface (promoting uniform dispersion within the carrier medium). A later, lower-momentum stream (9b) also impinges the planar impingement surface (13), ensuring its controlled scattering. This mechanism prevents particle agglomeration, ensures uniform particle size distribution, and optimizes mixing efficiency for applications like dry powder inhalers, tablet granulation, or aseptic filling processes.

graph TD
    A[Raw Material (Powder/Suspension)] --> B(Delivery Nozzle)
    B -- Injects Stream --> C[Mixing Chamber]
    C --> D[Dispersion Element]
    D -- Features --> E[Deflection Cone (11)]
    D -- Features --> F[Impingement Surface (13)]
    F -- Connected by --> G[Scattering Radius (14)]
    B -- Early Stream --> G
    B -- Late Stream --> F
    F -- Scatters Particles --> H[Agglomerate Breakup (Cone Direction)]
    F -- Scatters Particles --> I[Uniform Dispersion (Surface Edge Direction)]
    H & I --> J[Optimized Particle Distribution]

4. Integration with Emerging Technologies

Derivative 4.1: AI-Optimized Real-time Injection and Recess Cooling Control

Enabling Description:
This derivative integrates AI-driven optimization into the directly injecting internal combustion engine. The engine is equipped with an array of IoT sensors (e.g., in-cylinder pressure transducers, exhaust gas temperature and NOx sensors, piston surface thermocouples, injection nozzle temperature/wear sensors). These sensors provide real-time data to an Artificial Intelligence Engine Control Unit (AI-ECU). The AI-ECU, utilizing deep learning algorithms trained on extensive combustion datasets, dynamically adjusts the fuel injection parameters (timing, pressure, duration, multi-pulse strategy) and a newly introduced active cooling system for the piston recess (10). This active cooling, potentially using micro-channels within the piston (6) supplied with a circulating coolant, is precisely controlled to maintain optimal surface temperatures on the elevation (11) and adjoining surface (13) for fuel film evaporation and reduced coking. The AI predicts the optimal "virtual" recess geometry and injection strategy in real-time to maximize combustion efficiency and minimize emissions across the entire operating map, effectively learning and adapting to dynamic conditions and even engine wear.

sequenceDiagram
    participant S as IoT Sensors
    participant A as AI-ECU (Deep Learning)
    participant N as Injection Nozzle
    participant P as Piston Recess (w/ Active Cooling)
    participant C as Combustion Space
    participant E as Exhaust System

    loop Real-time Optimization
        S->>A: Send raw sensor data (P, T, NOx, etc.)
        A->>A: Process data & predict optimal parameters
        A->>N: Adjust injection (timing, pressure, pulses)
        A->>P: Control active recess cooling
        N->>C: Inject fuel
        P->>C: Shape fuel distribution
        C->>E: Combustion & emissions
        E->>S: Provide feedback (NOx, Temp)
    end

Derivative 4.2: IoT-Enabled Predictive Maintenance with Blockchain-Verified Emissions

Enabling Description:
This derivative enhances the directly injecting internal combustion engine with a comprehensive IoT and blockchain system for operational transparency and compliance. Each engine is equipped with an embedded IoT module that collects granular data from sensors within the combustion space (5), including precise fuel injection events (from nozzle 7), piston movement, and particularly, actual emissions data (CO2, NOx, Particulate Matter) from the exhaust. This data is timestamped, cryptographically hashed, and transmitted to a private blockchain network at regular intervals. The piston recess (10) design, with its specific elevation (11) and distribution surface (13), contributes to a documented combustion profile. The blockchain immutably records not only operational performance but also verifiable emissions reductions achieved through the engine's optimized design. This system facilitates predictive maintenance by identifying anomalous operational patterns on-chain and provides a transparent, tamper-proof record for carbon credit verification, regulatory compliance, and fuel provenance tracking, ensuring that the engine's design benefits are quantifiable and auditable.

graph TD
    A[Engine (US7513238)] --> B[IoT Sensors (Fuel, Emissions, Piston)]
    B --> C[IoT Gateway/Module]
    C -- Encrypt & Hash --> D{Blockchain Network}
    D -- Immutable Records --> E[Verified Emissions Data]
    D -- Immutable Records --> F[Operational Performance Logs]
    D -- Immutable Records --> G[Fuel Provenance]
    E --> H[Carbon Credit Verification]
    E --> I[Regulatory Compliance]
    F --> J[Predictive Maintenance Alerts]
    J --> K[Service Center]

5. The "Inverse" or Failure Mode

Derivative 5.1: Fail-Safe Fuel Diversion System for Engine Knock Mitigation

Enabling Description:
This derivative focuses on a fail-safe mode for the directly injecting internal combustion engine to mitigate severe engine knock or pre-ignition events. Upon detection of critical knocking (via an acoustic sensor array and pressure oscillations in the combustion space 5), the injection nozzle (7) and the piston recess (10) collaborate to execute a controlled fuel diversion. The nozzle (7) rapidly reconfigures its spray pattern (e.g., using a variable-geometry orifice or multi-pulse injection with altered angles) to direct the fuel jet (9) away from the typical impingement points on the radius (14) and planar surface (13). Instead, the fuel is intentionally directed towards a cooler, less reactive "diversion zone" on the piston crown (6) outside the primary recess, or towards the cylinder wall. Simultaneously, micro-actuators within the piston recess (10) might temporarily flatten the elevation (11) or alter the gradient of surface (13) to facilitate rapid quenching of any nascent flame fronts or to spread the fuel thinly, preventing uncontrolled combustion propagation and allowing for a safe engine shutdown or transition to a limp-home mode.

stateDiagram-v2
    state "Normal Operation" as Normal
    state "Knock Detected" as Knock
    state "Initiate Diversion" as Diversion
    state "Fuel Rerouted" as Rerouted
    state "Piston Recess Mod" as RecessMod
    state "Safe Shutdown/Limp-Home" as SafeMode

    Normal --> Knock : Critical Knock Detected
    Knock --> Diversion : Trigger Fail-Safe
    Diversion --> Rerouted : Nozzle alters spray
    Diversion --> RecessMod : Piston actuators modify recess
    Rerouted --> SafeMode : Fuel away from hot spots
    RecessMod --> SafeMode : Quench/Spread fuel
    SafeMode --> Off : Engine Shutdown

Derivative 5.2: Adaptive Low-Emissions Mode for Degraded Engine Operation

Enabling Description:
This derivative describes an adaptive low-emissions mode for the directly injecting internal combustion engine, specifically tailored for scenarios where engine components (e.g., partially clogged fuel injector, degraded sensor) are operating sub-optimally. In this mode, the engine's control unit (ECU) identifies the degraded component via diagnostics. Instead of full shutdown, the system dynamically adjusts the fuel injection strategy and leverages the piston recess (10) geometry to maintain acceptable emissions levels, albeit with reduced power. For example, if an injector orifice is partially blocked, the ECU might adjust the injection timing to ensure the available fuel jet (9) still optimally impinges the radius (14) or planar surface (13) for distribution, compensating for altered jet momentum or angle. Alternatively, the engine could operate exclusively with very early injection points (9a), relying heavily on the radius (14) for maximum distribution, to promote more homogeneous charge conditions and reduce particulate matter, even if it compromises peak power. This mode prioritizes emissions compliance and engine longevity over maximum performance, allowing for continued, albeit limited, operation until repairs can be made.

flowchart TD
    A[Engine Control Unit (ECU)] -- Detects --> B{Degraded Component / Sub-optimal Operation}
    B -- Activates --> C[Adaptive Low-Emissions Mode]
    C -- Adjusts --> D[Fuel Injection Strategy]
    C -- Optimizes Interaction with --> E[Piston Recess (10)]
    D --> F[Compensate for Clogged Injector]
    D --> G[Prioritize Early Injection (9a)]
    E --> H[Leverage Radius (14) for Max Distribution]
    E --> I[Ensure Impingement on Surface (13)]
    F & G & H & I --> J[Reduced Emissions]
    J --> K[Lower Power Output]
    J --> L[Continued Limited Operation]

---

Combination Prior Art Scenarios with Open-Source Standards

This section identifies scenarios where US Patent 7513238, or derivatives thereof, could be combined with existing open-source standards to further expand the scope of prior art.

1. US7513238 + OpenFOAM (Open Field Operation and Manipulation):
   Combining the specific piston recess geometry (elevation (11), adjoining surface (13), and radius (14)) and the fuel injection strategies of US7513238 with detailed Computational Fluid Dynamics (CFD) simulations performed using the open-source software OpenFOAM. Engineers can use OpenFOAM to model the entire combustion process, including the interaction of the injection jet (9) with the piston recess (10), the resulting fuel-air mixing, and subsequent combustion events. This involves creating precise mesh geometries of the combustion chamber and piston, implementing sophisticated multiphase flow and reaction chemistry models, and simulating the impact of varying injection parameters (angle, pressure, timing) on the fuel distribution. The simulations, openly available through OpenFOAM case studies or community forums, would demonstrate the "obviousness" of optimizing such geometries for improved mixing and combustion efficiency across a range of operating conditions, considering the known principles described in US7513238.

2. US7513238 + OPC UA (Open Platform Communications Unified Architecture):
   Integrating a directly injecting internal combustion engine, as described in US7513238, with an industrial control system utilizing the open-source OPC UA standard for data exchange. IoT sensors within the engine (e.g., in-cylinder pressure, fuel injection parameters, exhaust gas composition) would publish their data as OPC UA nodes. An OPC UA client application (e.g., a Supervisory Control and Data Acquisition (SCADA) system or a process control system) would subscribe to this data to monitor engine performance, diagnose faults, and potentially issue control commands (e.g., adjust injection timing within pre-defined limits) to optimize the engine's operation. This would demonstrate that connecting such a specialized engine to a standardized, open industrial communication framework for monitoring and control is a straightforward application of known technologies, rendering remote monitoring and control aspects "obvious."

3. US7513238 + Project Jupyter (Jupyter Notebooks):
   Utilizing Project Jupyter notebooks as an open-source platform for documenting, sharing, and executing scientific and engineering analyses related to the directly injecting internal combustion engine of US7513238. Researchers and developers could create Jupyter notebooks containing Python code (e.g., using libraries like NumPy, SciPy, Matplotlib) to analyze experimental data obtained from engines with the described piston recess geometry. This would include processing pressure traces, analyzing emission spectra, visualizing fuel spray patterns, and performing statistical analysis on combustion efficiency or pollutant formation. The notebooks could also incorporate explanatory text, equations, and interactive visualizations, serving as open documentation of research findings and demonstrating the "obviousness" of applying standard data analysis and visualization tools to optimize the performance of such engine designs, and for sharing the insights gained from the specific interaction between the fuel jet and piston recess.