Prosecution Insights
Last updated: April 19, 2026
Application No. 18/220,775

MICRO-TURBINE GAS GENERATOR AND PROPULSIVE SYSTEM

Final Rejection §103
Filed
Jul 11, 2023
Examiner
CHAU, ALAIN
Art Unit
3741
Tech Center
3700 — Mechanical Engineering & Manufacturing
Assignee
Jetoptera Inc.
OA Round
4 (Final)
80%
Grant Probability
Favorable
5-6
OA Rounds
2y 9m
To Grant
99%
With Interview

Examiner Intelligence

Grants 80% — above average
80%
Career Allow Rate
456 granted / 570 resolved
+10.0% vs TC avg
Strong +27% interview lift
Without
With
+27.2%
Interview Lift
resolved cases with interview
Typical timeline
2y 9m
Avg Prosecution
24 currently pending
Career history
594
Total Applications
across all art units

Statute-Specific Performance

§101
1.1%
-38.9% vs TC avg
§103
41.1%
+1.1% vs TC avg
§102
28.5%
-11.5% vs TC avg
§112
26.8%
-13.2% vs TC avg
Black line = Tech Center average estimate • Based on career data from 570 resolved cases

Office Action

§103
FINAL REJECTION The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA . Response to Amendment The Amendment filed 12/30/2025 has been entered. Claims 1-7, 9-16 remain pending in the application. Claims 9-16 were previously withdrawn from consideration. Claims 1-7 are hereby examined on the merits. 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. Claims 1-3 are rejected under 35 U.S.C. 103 as being unpatentable over Shapiro (EP 0173774, previously cited) in view of Heitmann (US 4,040,241 A). Regarding independent claim 1, Shapiro discloses a propulsion system for a vehicle (Shapiro Fig. 9 below; the system can be used for aircraft propulsion, Pg. 11, ln. 1-5), comprising: a first compressor 104 in fluid communication with a fluid source (free stream air entering the inlet of the system, Shapiro Fig. 9 below); a first conduit A coupled to the first compressor; a heat exchanger 108 in fluid communication with the first compressor 104 via the first conduit A (Shapiro Fig. 9 below, Pg. 21, ln. 19-24); a second conduit B positioned proximal to the heat exchanger 108 (receives the working fluid from the heat exchanger); a combustor 110 in fluid communication with the heat exchanger 108 via the second conduit B and configured to generate a high-temperature gas stream; a third conduit C coupled to the combustor 110 (Fig. 9 below, from downstream the turbine to the exit diffuser 112); and a first thrust augmentation device 114 in fluid communication with the combustor via the third conduit C (the augmenter is downstream the combustor, Shapiro Fig. 9 below, Pg. 22, ln. 13-17), the heat exchanger 108 being positioned within the gas stream generated by the combustor (the heat exchanger traverses the third conduit to be in heat exchange relationship with the gas stream from the combustor). PNG media_image1.png 262 805 media_image1.png Greyscale Shapiro fails to disclose the combustor is a toroidal combustor. Heitmann teaches a combustor for a gas turbine engine that is a toroidal combustor (Abstract, Col. 3, ln. 24-50, Col. 5, ln. 20-68, Col. 6, ln. 1-12). Therefore it would have been obvious to one of ordinary skill in the art at the time the invention was filed to have modified the system of Shapiro such that the combustor is a toroidal combustor, as taught by Heitmann, in order to provide an annular combustor configuration that promotes a toroidal recirculation pattern of circular cross-sectional configuration, which can interact with fuel injected radially outward in the form of a thin sheet and provides intimate mixing of fuel and air which can improve combustion efficiency and reduce emissions (Heitmann Abstract, Col. 3, ln. 24-50, Col. 5, ln. 20-68, Col. 6, ln. 1-12). Note, toroidal combustor arrangements are generally well-known and common in the art (see Teets US 2008/0041059 A1, US 8701416 B2; Howald US 4,563,875 A; Kydd US 3,309,866 A). Regarding claim 2, Shapiro in view of Heitmann teaches the propulsion system of claim 1, and Shapiro further teaches wherein the heat exchanger 108 is disposed within the third conduit C (Shapiro Fig. 9 above). Regarding claim 3, Shapiro in view of Heitmann teaches the propulsion system of claim 1, and Shapiro further teaches a turbine 106 coupled to the first compressor AC (the compressor AC from Skog via the main shaft, and the clutch incorporated from Skog as discussed in claim 1 above) and positioned between the combustor 110 and the heat exchanger 108 (Shapiro Fig. 9 above). Claim 4 is rejected under 35 U.S.C. 103 as being unpatentable over Shapiro in view of Heitmann, further in view of McCaffrey (US 20013/0004325). Regarding claim 4, Shapiro in view of Heitmann teaches the propulsion system of claim 3, but fails to teach wherein the turbine comprises ceramic matrix composites. FOSTER PEPPER PLLC 16579 1111 THIRD AVENUE, SUITE 3000 CUSTOMER NUMBER SEATTLE, WASHINGTON 98101-3299 PHONE (206) 447-4400 FAX (206) 447-9700 51570172 1 McCaffrey teaches a gas turbine engine turbine blade or vane 10 (Para. 0014) that is made from a ceramic matrix composite material 23 (CMC; a CMC core, Para. 0016, 0023-24). Therefore it would have been obvious to one of ordinary skill in the art at the time the invention was filed to have incorporated the ceramic matric composite, as taught by McCaffrey, to the turbine of Shapiro in view of Heitmann, in order to provide the turbine with a blade or vane that can withstand high temperatures without the need for internal cooling (McCaffrey Para. 0003), and that possesses high fracture toughness, a simple load path, low manufacturing cost, and thin leading edges and trailing edges (McCaffrey Para. 0032-33). Claims 5 & 6 are rejected under 35 U.S.C. 103 as being unpatentable over Shapiro in view of Heitmann, further in view of Skog (US 5,680,752). Regarding claims 5 & 6, Shapiro in view of Heitmann teaches the propulsion system of claim 3, wherein the turbine 106 is fixedly coupled to the first compressor 104 (Shapiro Fig. 9 above). Shapiro fails to teach further comprising a second compressor coupled to the turbine via a clutch. Shapiro does teach other embodiments with a second compressor (see for example Shapiro Fig. 1 & 2). Skog teaches a gas turbine engine (Skog Fig. 1B) comprising a turbine GT directly connected to a first compressor C (via a shaft A) and to a second compressor AC via a clutch 22 (Col. 3, In. 21-30). Therefore it would have been obvious to one of ordinary skill in the art at the time the invention was filed to have incorporated the second compressor coupled to the turbine via a clutch, as taught by Skog, to the system of Shapiro in view of Heitmann, in order to selectively provide additional airflow to the combustor (achieved by the clutch selectively engaging/disengaging the second compressor from the turbine), thereby improving the adaptability of the system to changing operational requirements (different power requirements, different air flow requirements, compensating for compressor aging, Skog, Col. 2, In. 18-32). Claim 7 is rejected under 35 U.S.C. 103 as being unpatentable over Shapiro in view ofHeitmann, further in view of Emmons (US 2,986,877). Regarding claim 7, Shapiro in view of Heitmann teaches the propulsion system of claim 1, but fails to disclose further comprising a swiveling connector coupling the third conduit to the first thrust augmentation device. Emmons teaches a propulsion system (Fig. 1 & 4) having a combustor (“fixed forward combustion section”, Claim 1) and a third conduit 17 coupled to the combustor (Fig. 4), further comprising a swiveling connector 19 coupling the third conduit to a thrust augmentation device 15 (afterburner section, Fig. 1-4). Therefore it would have been obvious to one of ordinary skill in the art at the time the invention was filed to have modified the system of Shapiro in view of Heitmann to include a swiveling connector coupling the third conduit to the first thrust augmentation device, as taught by Emmons, in order to provide a propulsion system that has a rotatable afterburner/thrust augmentor section capable of providing the aircraft with vertical take-off and forward thrust capabilities (Emmons Col. 1, ln. 36-50, Col. 3, ln. 18-42). Response to Arguments Applicant’s arguments with respect to claims 1-7 have been considered but are moot in view of the new grounds of rejection that was necessitated by Applicant’s amendment. However, to the extent possible, Applicant’s arguments have been addressed in the body of the rejections, at the appropriate locations. Conclusion Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a). A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action. Any inquiry concerning this communication or earlier communications from the examiner should be directed to ALAIN CHAU whose telephone number is (571)272-9444. The examiner can normally be reached M-F 9am-6pm PST. 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. /ALAIN CHAU/Primary Examiner, Art Unit 3741
Read full office action

Prosecution Timeline

Jul 11, 2023
Application Filed
Sep 20, 2024
Non-Final Rejection — §103
Dec 22, 2024
Response Filed
Jan 31, 2025
Final Rejection — §103
Jun 05, 2025
Request for Continued Examination
Jun 10, 2025
Response after Non-Final Action
Jun 27, 2025
Non-Final Rejection — §103
Dec 30, 2025
Response Filed
Mar 04, 2026
Final Rejection — §103 (current)

Precedent Cases

Applications granted by this same examiner with similar technology

Patent 12584446
UNIDIRECTIONAL FAN BRAKE FOR A GAS TURBINE ENGINE
2y 5m to grant Granted Mar 24, 2026
Patent 12577911
PARTICLE SEPARATION SYSTEM UPSTREAM OF A HEAT EXCHANGER IN A GAS TURBINE ENGINE
2y 5m to grant Granted Mar 17, 2026
Patent 12546273
FLUIDIC TURBO HEATER SYSTEM
2y 5m to grant Granted Feb 10, 2026
Patent 12546236
PARALLEL HEAT RECOVERY IN GAS POWER GENERATION
2y 5m to grant Granted Feb 10, 2026
Patent 12540732
COMBUSTOR OF GAS TURBINE
2y 5m to grant Granted Feb 03, 2026
Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

5-6
Expected OA Rounds
80%
Grant Probability
99%
With Interview (+27.2%)
2y 9m
Median Time to Grant
High
PTA Risk
Based on 570 resolved cases by this examiner. Grant probability derived from career allow rate.

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