Prosecution Insights
Last updated: April 19, 2026
Application No. 18/727,936

GAS SEALING STRUCTURE FOR INTERNAL COMBUSTION ENGINE

Non-Final OA §103
Filed
Jul 10, 2024
Examiner
BYRD, EUGENE G
Art Unit
3675
Tech Center
3600 — Transportation & Electronic Commerce
Assignee
Mitsubishi Heavy Industries Engine & Turbocharger Ltd.
OA Round
3 (Non-Final)
69%
Grant Probability
Favorable
3-4
OA Rounds
2y 12m
To Grant
79%
With Interview

Examiner Intelligence

Grants 69% — above average
69%
Career Allow Rate
580 granted / 836 resolved
+17.4% vs TC avg
Moderate +10% lift
Without
With
+9.8%
Interview Lift
resolved cases with interview
Typical timeline
2y 12m
Avg Prosecution
37 currently pending
Career history
873
Total Applications
across all art units

Statute-Specific Performance

§103
59.5%
+19.5% vs TC avg
§102
24.9%
-15.1% vs TC avg
§112
12.8%
-27.2% vs TC avg
Black line = Tech Center average estimate • Based on career data from 836 resolved cases

Office Action

§103
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 . Claim Rejections - 35 USC § 103 In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status. 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. Claim(s) 1, 4, 5 and 6 is/are rejected under 35 U.S.C. 103 as being unpatentable over Colwell (US 3209659) in view of Han (CN 2665549). Regarding claim 1, Colwell discloses a gas sealing structure Fig. 1 for an internal combustion engine, the internal combustion engine comprising: a cylinder block 2 that includes a space part 6 formed in a columnar shape; a cylinder liner 5 that is formed in a cylindrical shape and that is disposed in the space part; a piston 7 that is movably supported in an axial direction by the cylinder liner; a cylinder head 18 that is fastened to top of the cylinder block; and a gasket 25 that is disposed between the cylinder block and the cylinder head and between the cylinder liner and the cylinder head, and that includes a fire ring 26, wherein a contact area between the cylinder liner and the fire ring and a contact area between the cylinder head and the fire ring are the same. However, Colwell fails to explicitly disclose a first groove along a peripheral direction of the fire ring is provided on a contact surface of the cylinder liner and a second groove provided on a contact surface of the cylinder head. Han, a gas sealing structure Fig. 1, discloses the use of a first groove 5 Fig. 2 provided on a contact surface of the cylinder liner 3 and a second groove 5 provided on a contact surface of the cylinder head 1. Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to provide the cylinder head and liner of Colwell with first and second grooves as taught by Han in order to reduce pressure thus providing reliable sealing. Colwell also fails to explicitly disclose the configuration of the fire ring. Nevertheless, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the configuration of the fire ring to an array of shape necessary to accommodate a space in which it is positioned and since it has been held that the configuration of the claimed element was a matter of choice which a person of ordinary skill in the art would have found obvious absent persuasive evidence that the particular configuration of the claimed element was significant. In re Dailey, 357 F.2d 669, 149 USPQ 47 (CCPA 1966) Regarding claim 4, the combination discloses wherein the second groove 5 Fig. 2 includes a plurality of second groves, the first groove 5 includes one or more first groves, and a number of second grooves is greater than a number of first grooves. Regarding claim 5, the combination discloses wherein the second grooves 5 Fig. 2 include an inner second groove provided radially inside the first groove 5, and an outer second groove provided radially outside the first groove, and a radial length between the first groove and the inner second groove, and a radial length between the first groove and the outer second groove are same. Regarding claim 6, the combination discloses wherein the gasket 25 is formed of a soft material capable of forming a first convex part and a second convex part capable of penetrating into the first groove 5 and the second groove 5, by plastically deforming under surface pressure. Response to Arguments Applicant's arguments filed 12/15/25 have been fully considered but they are not persuasive. Applicant argues that the Cowell reference fails to teach or suggest the configuration of the claimed fire ring. This is not persuasive since as stated above it would have been an obvious design choice or engineering expedient for one of ordinary skill in the art to modify a shape of the fire ring in order to scale and/or otherwise optimize the disclosed structure to achieve its intended use in a particular environment of intended use benefitting from same wherein configuring fire rings to intended use is well known in the art and would not otherwise affect function of the invention. Also see US Pat. 4474147 and US Pat. 5636850 for reference of an array of possibilities for configuring shapes of fire rings. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to EUGENE G BYRD whose telephone number is (571)270-1824. The examiner can normally be reached Monday-Friday 9am-5:30pm. 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, Kristina Fulton can be reached at 5712727376. 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. /EUGENE G BYRD/Primary Examiner, Art Unit 3675
Read full office action

Prosecution Timeline

Jul 10, 2024
Application Filed
Apr 30, 2025
Non-Final Rejection — §103
Aug 05, 2025
Response Filed
Sep 17, 2025
Final Rejection — §103
Dec 15, 2025
Request for Continued Examination
Dec 28, 2025
Response after Non-Final Action
Jan 24, 2026
Non-Final Rejection — §103 (current)

Precedent Cases

Applications granted by this same examiner with similar technology

Patent 12595847
ENERGIZING ELEMENT AND METHODS OF MAKING AND USING THE SAME
2y 5m to grant Granted Apr 07, 2026
Patent 12595848
SOLID PLATE AND STUFFING BOX COMPRISING THE SOLID PLATE
2y 5m to grant Granted Apr 07, 2026
Patent 12584416
O-RING FOR GAS TURBINE ENGINE
2y 5m to grant Granted Mar 24, 2026
Patent 12578017
PISTON RING
2y 5m to grant Granted Mar 17, 2026
Patent 12577947
JUNK RING FOR RECIPROCATING PUMP
2y 5m to grant Granted Mar 17, 2026
Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

3-4
Expected OA Rounds
69%
Grant Probability
79%
With Interview (+9.8%)
2y 12m
Median Time to Grant
High
PTA Risk
Based on 836 resolved cases by this examiner. Grant probability derived from career allow rate.

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