Prosecution Insights
Last updated: April 19, 2026
Application No. 18/693,097

INTERNAL COMBUSTION ENGINE COMPRISING A SPARK PLUG AND NEGATIVE SPARK POSITIONS

Non-Final OA §103§112
Filed
Mar 18, 2024
Examiner
KIM, JAMES JAY
Art Unit
3747
Tech Center
3700 — Mechanical Engineering & Manufacturing
Assignee
Robert Bosch GmbH
OA Round
4 (Non-Final)
70%
Grant Probability
Favorable
4-5
OA Rounds
2y 4m
To Grant
97%
With Interview

Examiner Intelligence

Grants 70% — above average
70%
Career Allow Rate
467 granted / 665 resolved
At TC average
Strong +27% interview lift
Without
With
+27.1%
Interview Lift
resolved cases with interview
Typical timeline
2y 4m
Avg Prosecution
28 currently pending
Career history
693
Total Applications
across all art units

Statute-Specific Performance

§101
0.4%
-39.6% vs TC avg
§103
54.8%
+14.8% vs TC avg
§102
22.9%
-17.1% vs TC avg
§112
20.1%
-19.9% vs TC avg
Black line = Tech Center average estimate • Based on career data from 665 resolved cases

Office Action

§103 §112
DETAILED ACTION Notice of Pre-AIA or AIA Status The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA . Withdrawn Allowable Subject Matter The indicated allowability of claims 19 and 20 are withdrawn in view of the newly discovered references to Phillips (US 2,652,044) and Klonis et al (US 2005/0092285 hereinafter “Klonis”). Rejections based on the newly cited reference(s) follow. Claim Rejections - 35 USC § 112 The following is a quotation of the first paragraph of 35 U.S.C. 112(a): (a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention. The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112: The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention. Claim 16 is rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the enablement requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to enable one skilled in the art to which it pertains, or with which it is most nearly connected, to make and/or use the invention. Claim 16 recites in the 2nd line of the claim “the spark gap has a distance to the combustion chamber roof of the cylinder of at least 0 mm and at most -15 mm”. This is mentioned in the Specification for this range, but the Specification does not recite nor describe how a negative number can be greater than zero. Wherein, it is understood that all negative numbers are less than zero and all positive numbers are greater than zero. The following is a quotation of 35 U.S.C. 112(b): (b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention. The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph: The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention. Claim 16 is rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention. Claim 16 recites in the 2nd line of the claim “the spark gap has a distance to the combustion chamber roof of the cylinder of at least 0 mm and at most -15 mm”. It is unclear how a value having a minimum of 0 can have a maximum value that is less than 0. It is further unclear how a spark gap having a distance to the combustion chamber roof of 0 mm could have a ratio between 0.05 to 25 as recited in independent claim 1, any value divided by zero will produce a ratio of infinity, and any value between 0 and -15 would produce a negative ratio. For the purposes of examination, it will be understood as a minimum greater than 0 and a maximum of 15 mm. Claims 23 and 24 recites the limitation "each case" in the 3rd line of each claim. There is insufficient antecedent basis for this limitation in the claim. Claim 24 recites in the 2nd line of the claim “includes an angle of 90 degrees and greater than 30 degrees”. It is unclear whether the angle is to be 90 degrees or greater than 30 degrees. It will be understood as less than 90 degrees and greater than 30 degrees for the purposes of examination. Claim Rejections - 35 USC § 103 The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action: A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, 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 to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made. The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows: 1. Determining the scope and contents of the prior art. 2. Ascertaining the differences between the prior art and the claims at issue. 3. Resolving the level of ordinary skill in the pertinent art. 4. Considering objective evidence present in the application indicating obviousness or nonobviousness. Claims 15-17, 19 and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Phillips (US 2,652,044) in view of Klonis et al (US 2005/0092285 hereinafter “Klonis”). In regards to claim 15: Phillips teaches an internal combustion engine (1) comprising at least one combustion chamber (3) having a combustion chamber roof formed in an engine head, a spark plug with a longitudinal axis, the spark plug including a housing with an end face which faces the combustion chamber, an insulator (7) which is disposed in the housing, a center electrode (8) which is disposed in the insulator (7), and at least one ground electrode (9) which is disposed on or in the housing and together with the center electrode forms at least one spark gap, wherein the spark plug is mounted in a bore formed in the engine head (via threads 5) wherein a ratio of a wall thickness of the spark plug housing to a distance between the spark gap and the combustion chamber roof is from 0.05 to 25 (Shown below in annotated Figure 1, the distances are shown together on the bottom left, 1 unit of wall thickness is compared to 2 units of spark gap distance, with the ratio of wall thickness to distance between the spark gap and the combustion chamber roof is about 2:3 or 0.66, and greater than a ratio of 1:2 or 0.5 and less than a ratio of 1:1 or 1) and wherein the at least one ground electrode (9) is disposed inside the housing in a bore (10) formed in a wall of the housing, the ground electrode being welded (welds 11) into the bore. Gozawa does not specify the combustion chamber to be cylindrical and a piston that can move in the cylinder and is configured to ignite a fuel/air mixture in the combustion chamber. Klonis teaches an engine (10) having at least one cylinder and a cylindrical piston (16) inside of the cylinder forming a combustion chamber (14) with the piston, cylinder side walls, and a cylinder head (10) and combusting a mixture of air and fuel (Paragraph [0002]). It would have been obvious to one of ordinary skill in the art at the time of filing of the application to specify the engine of Phillips to have at least one cylinder, a cylindrical piston, and a cylinder head that combusts an air and fuel mixture as taught by Klonis in order to produce a known style of engine. Combustion engines in the automotive space dominantly use cylinders and cylindrical pistons to avoid a reciprocating piston having sharp edges that can chip away during use and loads are easier to spread across the piston versus a square piston or other shape. Cylinder heads are known in the art for housing the valve train, which is used in combustion engines to allow the air to enter and exhaust to exit a combustion chamber. PNG media_image1.png 668 404 media_image1.png Greyscale Annotated Figure 1 of Phillips In regards to claim 16: Phillips doesn’t specify the spark gap has a distance to the combustion chamber roof of the cylinder of at least 0 mm and at most 15 mm, wherein a contour of the combustion chamber roof is continued by an imaginary line at the bore and the imaginary line is a reference plane having a value of 0 mm. However, the court upheld In Gardner v. TEC Syst., Inc., 725 F.2d 1338, 220 USPQ 777 (Fed. Cir. 1984) that changes in relative dimensions would not perform differently than the prior art, wherein in the instant case the prior art teaches a spark gap adjacent to a combustion chamber roof, and wherein a smaller engine requiring a smaller spark plug would produce a smaller distance between the spark gap and the combustion chamber roof. In regards to claim 17: Phillips teaches the combustion chamber-facing end face of the housing is disposed outside the combustion chamber, inside the bore for the spark plug. In regards to claim 19: Phillips teaches a combustion chamber, a combustion chamber roof, and a spark plug with a longitudinal axis, the spark plug including: a housing with an end face which faces the combustion chamber, an insulator which is disposed in the housing, a center electrode which is disposed in the insulator, and at least one ground electrode which is disposed on or in the housing and together with the center electrode forms at least one spark gap, wherein the spark plug is mounted in a bore formed in the cylinder head; wherein the spark gap of the spark plug is located outside the combustion chamber, wherein the spark plug is disposed within a region. Phillips does not teach at least one cylinder wherein the combustion chamber is delimited by side walls of the cylinder and the combustion chamber roof, which is formed by a cylinder head of the cylinder, and a piston that can move in the cylinder and does not specify the spark plug is configured to ignite a fuel/air mixture in the combustion chamber and wherein the region is a circular area with a midpoint of the combustion chamber roof as a center of the circular areas and has a radius of 15% of an inner cylinder radius. Klonis teaches an engine (10) having at least one cylinder and a cylindrical piston (16) inside of the cylinder forming a combustion chamber (14) with the piston, cylinder side walls, and a cylinder head (10) and combusting a mixture of air and fuel (Paragraph [0002]), the combustion chamber delimited by side walls of the cylinder and a combustion chamber roof and a spark plug in a region that is a circular area with a midpoint of the combustion chamber roof as a center of the circular areas and has a radius of 15% of an inner cylinder radius. (Shown below in annotated Figure 1 of Klonis), wherein a region tied to a percentage of a cylinder radius can always be drawn, and wherein a spark plug will can always exist in a region that has a radius greater than 0, it may not be disposed entirely in the region when the radius is close to 0, but it will be disposed within the region. It would have been obvious to one of ordinary skill in the art at the time of filing of the application to specify the engine of Phillips to have at least one cylinder, a cylindrical piston, and a cylinder head that combusts an air and fuel mixture as taught by Klonis in order to produce a known style of engine. Combustion engines in the automotive space dominantly use cylinders and cylindrical pistons to avoid a reciprocating piston having sharp edges that can chip away during use and loads are easier to spread across the piston versus a square piston or other shape. Cylinder heads are known in the art for housing the valve train, which is used in combustion engines to allow the air to enter and exhaust to exit a combustion chamber. Furthermore, having arbitrary regions without any structural limitations (such as a threaded bore for the spark plug being 15% of the inner cylinder radius), one of ordinary skill in the art can measure a cylinder, and calculate a measurement that is equal to 15% of the radius of the cylinder. PNG media_image2.png 1085 899 media_image2.png Greyscale Annotated Figure 1 of Klonis In regards to claim 20: Phillips teaches an internal combustion engine (1) comprising at least one combustion chamber (3), a spark plug with a longitudinal axis, the spark plug including: a housing with an end face which faces the combustion chamber, an insulator which is disposed in the housing, a center electrode which is disposed in the insulator, and at least one ground electrode which is disposed on or in the housing and together with the center electrode forms at least one spark gap, wherein the spark plug is mounted in a bore formed in the engine head; wherein the spark gap of the spark plug is located outside the combustion chamber. Phillips does not teach at least one cylinder wherein the combustion chamber is delimited by side walls of the cylinder and the combustion chamber roof, which is formed by a cylinder head of the cylinder, and a piston that can move in the cylinder and does not specify the spark plug is configured to ignite a fuel/air mixture in the combustion chamber and wherein the spark plug is not disposed outside a region, wherein the region is a circular area with a midpoint of the combustion chamber roof as a center of the circular area and has a radius of 15% of an inner cylinder radius. Klonis teaches an engine (10) having at least one cylinder and a cylindrical piston (16) inside of the cylinder forming a combustion chamber (14) with the piston, cylinder side walls, and a cylinder head (10) and combusting a mixture of air and fuel (Paragraph [0002]), the combustion chamber delimited by side walls of the cylinder and a combustion chamber roof and a spark plug in a region that is a circular area with a midpoint of the combustion chamber roof as a center of the circular areas and has a radius of 15% of an inner cylinder radius. (Shown above in annotated Figure 1 of Klonis), wherein a region tied to a percentage of a cylinder radius can always be drawn, and wherein a spark plug will can always exist in a region that has a radius greater than 0, it may not be disposed entirely in the region when the radius is close to 0, but it will be disposed within the region. It would have been obvious to one of ordinary skill in the art at the time of filing of the application to specify the engine of Phillips to have at least one cylinder, a cylindrical piston, and a cylinder head that combusts an air and fuel mixture as taught by Klonis in order to produce a known style of engine. Combustion engines in the automotive space dominantly use cylinders and cylindrical pistons to avoid a reciprocating piston having sharp edges that can chip away during use and loads are easier to spread across the piston versus a square piston or other shape. Cylinder heads are known in the art for housing the valve train, which is used in combustion engines to allow the air to enter and exhaust to exit a combustion chamber. Furthermore, changes in relative dimensions were held to not be inventive In Gardner v. TEC Syst., Inc., 725 F.2d 1338, 220 USPQ 777 (Fed. Cir. 1984), cert. denied, 469 U.S. 830, 225 USPQ 232 (1984), and in the instant case changing the width (bore) of a cylinder is known in the art and along with the stroke length of the piston defining the combustion chamber volume, is altered and adjusted to find a balance between criteria such as but not limited to: power output, fuel efficiency, desired engine speeds, thermal efficiency, ease of cooling, and engine block size constraints. Claims 18 and 21-24 are rejected under 35 U.S.C. 103 as being unpatentable over Phillips and Klonis as applied to claim 15 above, and further in view of Imai et al (US 12,080,997 hereinafter “Imai”). In regards to claim 18: Phillips does not teach the combustion chamber-facing end face of the housing is at least partly flush with the combustion chamber roof. Imai teaches a combustion chamber-facing end face of a housing is at least partly flush with a combustion chamber roof. It would have been obvious to one of ordinary skill in the art at the time of filing of the application to have the combustion chamber-facing end of Phillips to be flush with the combustion chamber roof as taught by Imai in order to have the spark plug installed in the bore without any area adjacent the spark plug to be exposed to carbon build up. In regards to claim 21: Phillips does not teach the combustion chamber-facing end face of the housing includes a surface, wherein a shape of the surface corresponds to a contour of the combustion chamber roof. Imai teaches a combustion chamber-facing end face of the housing includes a surface, wherein a shape of the surface corresponds to a contour of the combustion chamber roof. It would have been obvious to one of ordinary skill in the art at the time of filing of the application to have the combustion chamber-facing end of Phillips to correspond to a contour of a combustion chamber roof as taught by Imai in order to have the spark plug installed in the bore without any area adjacent the spark plug to be exposed to carbon build up. In regards to claim 22: Phillips as modified teaches the surface is a flat surface perpendicular to the longitudinal axis of the spark plug (Figure 1 of Imai). In regards to claim 23: Imai teaches the surface of the combustion chamber roof is a flat surface that includes an angle of less than 90° and greater than 30°, with the longitudinal axis of the spark plug, wherein in each case a smaller included angle between the surface and the longitudinal axis is considered (Shown in Figure 2, the surface has a flat surface that transitions to an angled surface on the outer edges). In regards to claim 24: Phillips as modified teaches the surface is a curved surface that includes an angle less than of 90° and greater than 30°, with the longitudinal axis X of the spark plug, wherein in each case the smaller included angle between the surface and the longitudinal axis is considered, wherein the curved surface of Imai extends 360 degrees in a circular manner (Figure 1 of Imai is a sectioned view), and points on the curved surface will produce angles with the longitudinal axis of the spark plug between 0 and 360 degrees, wherein angles between 30-90 degrees are within 0-360. Claim 25 is rejected under 35 U.S.C. 103 as being unpatentable over Phillips and Klonis and Imai as applied to claim 24 above, and further in view of Keller et al (US 2013/0076224 hereinafter “Keller”). In regards to claim 25: Phillips does not teach the cylinder head and/or the spark plug each have a mark, so that the spark plug can be mounted in the cylinder in an aligned manner. Keller teaches a mark on a spark plug in order to aid in the aligning of a spark plug (Paragraph [0037] recites “As another example, the ground electrode body 18 can be attached to the metallic shell 16 at a pre-determined position with respect to a line, mark, or other visual indicia that an installer can use to align with corresponding visual indicia on the engine, or that can be read by a machine vision system. These are of course only examples, and other methods may be employed.”). It would have been obvious to one of ordinary skill in the art at the time of the invention to modify the spark plug of Phillips to have a mark as taught by Keller in order to aid in the aligning of the spark plug. Claim 26 is rejected under 35 U.S.C. 103 as being unpatentable over Phillips and Klonis as applied to claim 15 above, and further in view of Hartmann et al (US 7,977,856 hereinafter “Hartmann”). In regards to claim 26: Phillips teaches the spark plug includes a thread (2) on an outer side of the housing, with which the spark plug is screwed into the bore formed in the cylinder head, and an outer sealing surface, wherein, between the outer sealing surface and an end of the thread facing away from the combustion chamber. Phillips does not teach the housing includes a non-threaded region which is longer in the longitudinal axis of the spark plug than a thickness of an outer seal disposed on the outer sealing surface. Hartmann teaches a non-threaded region that is longer in a longitudinal axis of a spark plug than a thickness of an outer seal in order to provide a seal that can be specifically tightened to a desired torque and have room for rotation to achieve a desired alignment (Col 1, Lines 43-60, and shown below in annotated Figure 2 of Hartmann). It would have been obvious to one of ordinary skill in the art at the time of the invention modify the spark plug of Phillips to have a non-threaded region that is longer in a longitudinal axis of a spark plug than a thickness of an outer seal as taught by Hartmann in order to provide a seal that can be specifically tightened to a desired torque and have room for rotation to achieve a desired alignment. PNG media_image3.png 753 845 media_image3.png Greyscale Annotated Figure 2 of Hartmann Claim 27 is rejected under 35 U.S.C. 103 as being unpatentable over Phillips and Klonis as applied to claim 15 above, and further in view of Nakano et al (US 2019/0020179 hereinafter “Nakano”). In regards to claim 27: Phillips teaches a width of the spark gap is specified by an electrode spacing between the center electrode and the at least one ground electrode, but does not specify the electrode spacing between the center electrode and the at least one ground electrode is not greater than 0.4 mm and not less than 0.05 mm. Nakano teaches a spacing between a center electrode (30) and a ground electrode (15) to be 0.4 mm in order to have a gap that is sized to properly create a series of sparks (Paragraph [0052]). It would have been obvious to one of ordinary skill in the art at the time of the invention to specify the electrode spacing of Phillips to not be greater than 0.4 mm as taught by Nakano in order to have a gap that is sized to properly create a series of sparks. Claim 28 is rejected under 35 U.S.C. 103 as being unpatentable over Phillips and Klonis as applied to claim 15 above, and further in view of Schiliro (US 2015/0361876). In regards to claim 28: Phillips does not teach the internal combustion engine can be operated with hydrogen or a hydrogen mixture as a fuel at least within a partial operating range with a lambda number of at least 1.8. Schiliro teaches an internal combustion engine (1) that can be operated with hydrogen or a hydrogen mixture as a fuel at least within a partial operating range with a lambda number of at least 1.8 (Paragraph [0010]) in order to increase the rate of combustion thus the efficiency of the engine (Paragraph [0018]). It would have been obvious to one of ordinary skill in the art at the time of the invention to have the engine of Phillips operate with hydrogen or a hydrogen mixture as taught by Schiliro in order to increase the rate of combustion thus the efficiency of the engine. Response to Arguments Applicant’s arguments with respect to claims 15-28 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to JAMES JAY KIM whose telephone number is (571)270-7610. The examiner can normally be reached M-F 9-5 EST. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Logan Kraft can be reached at (571) 270-5065. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /JAMES J KIM/Examiner, Art Unit 3747 /HUNG Q NGUYEN/Primary Examiner, Art Unit 3747
Read full office action

Prosecution Timeline

Mar 18, 2024
Application Filed
Sep 11, 2024
Non-Final Rejection — §103, §112
Dec 12, 2024
Response Filed
Dec 30, 2024
Final Rejection — §103, §112
Apr 07, 2025
Response after Non-Final Action
May 06, 2025
Request for Continued Examination
May 08, 2025
Response after Non-Final Action
May 21, 2025
Non-Final Rejection — §103, §112
Aug 26, 2025
Response Filed
Dec 18, 2025
Non-Final Rejection — §103, §112
Mar 27, 2026
Response Filed

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Prosecution Projections

4-5
Expected OA Rounds
70%
Grant Probability
97%
With Interview (+27.1%)
2y 4m
Median Time to Grant
High
PTA Risk
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