Prior art

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.