Prosecution Insights
Last updated: April 19, 2026
Application No. 19/186,619

GAS TURBINE SYSTEM

Non-Final OA §102§112
Filed
Apr 23, 2025
Examiner
KIM, CRAIG SANG
Art Unit
3741
Tech Center
3700 — Mechanical Engineering & Manufacturing
Assignee
DOOSAN ENERBILITY CO., LTD.
OA Round
2 (Non-Final)
86%
Grant Probability
Favorable
2-3
OA Rounds
3y 1m
To Grant
96%
With Interview

Examiner Intelligence

Grants 86% — above average
86%
Career Allow Rate
667 granted / 775 resolved
+16.1% vs TC avg
Moderate +10% lift
Without
With
+10.2%
Interview Lift
resolved cases with interview
Typical timeline
3y 1m
Avg Prosecution
26 currently pending
Career history
801
Total Applications
across all art units

Statute-Specific Performance

§101
0.7%
-39.3% vs TC avg
§103
41.1%
+1.1% vs TC avg
§102
33.9%
-6.1% vs TC avg
§112
19.5%
-20.5% vs TC avg
Black line = Tech Center average estimate • Based on career data from 775 resolved cases

Office Action

§102 §112
DETAILED ACTION This is a non-final rejection in response to amendment filed 11/13/25. Claims 1 and 3-18 are currently pending. Response to Arguments Applicant’s arguments, with respect to claims 1 and 3-17 have been fully considered and are persuasive. The rejections of 1 and 3-17 has been withdrawn. Claims are further rejected as shown below. Claim Rejections - 35 USC § 112 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. Claims 1, 3-18 are 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. Regarding claim 1,17,18, “exterior air” is indefinite as it is unclear what exterior refers to. It is believed the exterior air means ambient air. Subsequent dependent claims are further rejected. Regarding claim 3 and 9, “upside the first heat exchange part” is indefinite as it is unclear what upside refers to. It is also unclear if “circulation line” is the same as the “recirculation line”. Regarding claim 8, “fuel having passed via the first heat exchange part” is indefinite as it is unclear when the fuel passes through the first heat exchange part, claim 3 claims it going through “the second heat exchange part”. Regarding claim 12 and 18, “ejection nozzle connected to an outlet end” is indefinite as it is unclear what the outlet end is for. Claim Rejections - 35 USC § 102 The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action: A person shall be entitled to a patent unless – (a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention. Claim(s) 18 is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Ball, JR. et al. (US 2014/0102071). Regarding independent claim 18, Ball teaches a gas turbine system 12 comprising: an exhaust gas guide duct 38 provided on a downstream side of a gas turbine, and configured to guide exhaust gas discharged from the gas turbine to an outside [0017-0020]; a recirculation line connected to the exhaust gas guide duct, and configured to recirculate the exhaust gas extracted from the exhaust gas guide duct back into the exhaust gas guide duct [0023]; a fuel supply line configured to supply a fuel to a combustor of the gas turbine [0019]; and a heat exchanger 50 configured to heat the fuel using the exhaust gas recirculating along the recirculation line [0019], an ejection nozzle (where 94 connects to the exhaust gas guide duct 38) connected to an outlet end, and configured to eject the exhaust gas to an interior of the exhaust gas guide duct [0023]. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to CRAIG SANG KIM whose telephone number is (571)270-1418. The examiner can normally be reached 7:00 AM - 3:00 PM. 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, Devon Kramer can be reached at 571-272-7118. 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. /CRAIG KIM/ Primary Examiner Art Unit 3741
Read full office action

Prosecution Timeline

Apr 23, 2025
Application Filed
Aug 13, 2025
Non-Final Rejection — §102, §112
Nov 13, 2025
Response Filed
Feb 05, 2026
Non-Final Rejection — §102, §112 (current)

Precedent Cases

Applications granted by this same examiner with similar technology

Patent 12601296
GAS TURBINE ENGINE HAVING A HEAT EXCHANGER LOCATED IN AN ANNULAR DUCT
2y 5m to grant Granted Apr 14, 2026
Patent 12601297
GAS TURBINE ENGINE HAVING A HEAT EXCHANGER LOCATED IN AN ANNULAR DUCT
2y 5m to grant Granted Apr 14, 2026
Patent 12601313
SYSTEMS AND METHODS FOR ROCKET PROPULSION INCLUDING ROCKET MOTOR USING POWDER MONOPROPELLANT
2y 5m to grant Granted Apr 14, 2026
Patent 12560326
MAIN MIXER IN AN AXIAL STAGED COMBUSTOR FOR A GAS TURBINE ENGINE
2y 5m to grant Granted Feb 24, 2026
Patent 12560118
GAS TURBINE ENGINE HAVING A HEAT EXCHANGER LOCATED IN AN ANNULAR DUCT
2y 5m to grant Granted Feb 24, 2026
Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

2-3
Expected OA Rounds
86%
Grant Probability
96%
With Interview (+10.2%)
3y 1m
Median Time to Grant
Moderate
PTA Risk
Based on 775 resolved cases by this examiner. Grant probability derived from career allow rate.

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