Prosecution Insights
Last updated: April 19, 2026
Application No. 18/777,349

FUEL THERMAL MANAGEMENT SYSTEMS AND RELATED METHODS

Final Rejection §103
Filed
Jul 18, 2024
Examiner
KIM, CRAIG SANG
Art Unit
3741
Tech Center
3700 — Mechanical Engineering & Manufacturing
Assignee
GE Avio S R L
OA Round
2 (Final)
86%
Grant Probability
Favorable
3-4
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

§103
DETAILED ACTION This is a final rejection in response to the amendments filed 1/2/26. Claims 1, 3-18, and 21-23 are currently pending. Response to Arguments Applicant’s arguments with respect to claim(s) 1, 3-18 and 21-23 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. 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. Claim(s) 1, 3-11, 14-15,17, and 18 is/are rejected under 35 U.S.C. 103 as being unpatentable over Hudson et al. US4776536 in view of Weber US9561857. Regarding independent claim 1 and 11, Hudson teacher a fuel thermal control system comprising: a heat exchanger 19,23,25,27 coupled to the flowline 18 to receive the fluid, the heat exchanger to heat the fluid to a first temperature (col.3, l. 63-col.4, l. 13); a feed tank 12 coupled to the flowline to receive the fluid, the feed tank including a first inlet 40 and a second inlet 16, the first inlet to receive a first portion of the fluid from the heat exchanger at the first temperature, the second inlet to receive a second portion of the fluid at a second temperature less than the first temperature, wherein the first portion of the fluid and the second portion of the fluid mix in the feed tank to form a third portion having a third temperature between the first temperature and the second temperature (col.3, l. 55-col.4, l. 13); and a fuel heat exchanger 17 coupled to the flowline, the fuel heat exchanger to receive the fluid and a fuel. Weber teaches a flowline to carry a fluid but is silent to a closed loop. Weber teaches it was known to have a closed loop cooling system (col. 3, l. 30-43). It would have been obvious to one of ordinary skill in the art at the time of filing to provide the engine of Hudson with the closed loop cooling system of Weber, as Weber teaches improved cooling ability of the cooling system (col. 4, l. 43-49). Regarding dependent claim 3, Hudson in view of Weber teaches the invention as claimed and discussed above. Hudson further teaches wherein the flowline is coupled to a fuel heater 47 in which the fluid transfers heat to a fuel to be injected into a combustor (col. 4, l. 25). Regarding dependent claim 4 and 14, Hudson in view of Weber teaches the invention as claimed and discussed above. Hudson further teaches wherein the flowline includes a main loop 18/32 and a fuel heater bypass section 36/38, wherein the main loop carries the fluid to the fuel heater, and wherein the fuel heater bypass section causes the fluid to bypass the fuel heater (col.3, l. 31-62). Regarding dependent claim 5 and 15, Hudson in view of Weber teaches the invention as claimed and discussed above. Hudson further teaches further including a valve 45 to control a ratio of a fourth portion 34 of the fluid that flows to the fuel heater compared to a fifth portion of the fluid that flows to the fuel heater bypass section 36. Regarding dependent claim 6, Hudson in view of Weber teaches the invention as claimed and discussed above. Hudson further teaches further including fuel temperature control circuitry 45,48 to control a ratio of the first portion of the fluid to the second portion of the fluid to adjust the third temperature based on a temperature measurement from one or more sensors operatively coupled to the flowline between the feed tank and the fuel heater (col.3, l. 55-col.4, l. 18). Regarding dependent claim 7 and 17, Hudson in view of Weber teaches the invention as claimed and discussed above. Hudson further teaches wherein the flowline is a heat exchange fluid flowline, further including fuel temperature control circuitry to control a ratio of the first portion of the fluid to the second portion of the fluid to adjust the third temperature based on a temperature measurement from one or more sensors operatively coupled to a fuel flowline between the fuel heater and the combustor (col.3, l. 55-col.4, l. 18). Regarding dependent claim 8, Hudson in view of Weber teaches the invention as claimed and discussed above. Hudson further teaches further including fuel temperature control circuitry to increase a ratio of the first portion of the fluid to the second portion of the fluid when a fuel temperature is less than a target temperature (col.3, l. 55-col.4, l. 28). Regarding dependent claim 9, Hudson in view of Weber teaches the invention as claimed and discussed above. Hudson further teaches further including a valve positioned upstream of the second inlet, and wherein the fuel temperature control circuitry adjusts a position of the valve to increase the ratio (col.3, l. 55-col.4, l. 28). Regarding dependent claim 10 and 18, Hudson in view of Weber teaches the invention as claimed and discussed above. Hudson further teaches further including fuel temperature control circuitry to reduce a ratio of the first portion of the fluid to the second portion of the fluid when a fuel temperature is greater than a target temperature (col.3, l. 55-col.4, l. 28). Claim(s) 12-13 is/are rejected under 35 U.S.C. 103 as being unpatentable over Hudson in view of Weber and further in view of Soriano et al. US 2016/0297538. Regarding dependent claim 12, Hudson in view of Weber teaches the invention as claimed and discussed above. Hudson in view of Weber is silent to a waste heat recovery heat exchanger configured to absorb heat to obtain the first temperature. Soriano teaches including a waste heat recovery heat exchanger 112 coupled to the flowline, the waste heat recovery heat exchanger to cause the fluid to absorb heat to obtain the first temperature [0018]. It would have been obvious to one of ordinary skill in the art at the time of filing to provide Hudson in view of Weber with the heat exchanger configuration of Soriano as Soriano teaches it helps prevent fuel freezing in storage tanks during cod environments [0005]. Regarding dependent claim 13, Hudson in view of Weber and further in view of Soriano teaches the invention as claimed and discussed above. Soriano further teaches wherein a portion of the flowline bypasses the waste heat recovery heat exchanger to deliver the fluid at the second temperature to the second inlet of the feed tank [0017]. Claim(s) 16 is/are rejected under 35 U.S.C. 103 as being unpatentable over Hudson in view of Weber and further in view of Doman US 2021/0229827. Regarding dependent claim 16, Hudson in view of Weber teaches the invention as claimed and discussed above. Hudson in view of Weber is silent to further including a mixer coupled to the main loop and the fuel heater bypass section to mix the fluid that flows through the fuel heater heat exchanger with the fluid that bypasses the fuel heater heat exchanger. Doman teaches further including a mixer coupled to the main loop and the fuel heater bypass section to mix the fluid that flows through the fuel heater heat exchanger with the fluid that bypasses the fuel heater heat exchanger [0037]. It would have been obvious to one of ordinary skill in the art at the time of filing to provide Hudson in view of Weber with the mixer coupled to the main loop and the fuel heater bypass section to mix the fluid that flows through the fuel heater heat exchanger with the fluid that bypasses the fuel heater heat exchanger as Doman teaches bypassing heat exchange based on temperature, which results in efficiency [0018, 0040]. Claim(s) 21 and 23 is/are rejected under 35 U.S.C. 103 as being unpatentable over Hudson in view of Soriano. Regarding independent claim 21, Hudson teaches a fuel thermal control system comprising: a flowline 18 to carry a fluid; a heat exchanger 19,23,25,27 coupled to the flowline 18 to receive the fluid, the heat exchanger to heat the fluid to a first temperature (col.3, l. 63-col.4, l. 13); a feed tank 12 coupled to the flowline to receive the fluid, the feed tank including a first inlet 40 and a second inlet 16, the first inlet to receive a first portion of the fluid from the heat exchanger at the first temperature, the second inlet to receive a second portion of the fluid at a second temperature less than the first temperature, wherein the first portion of the fluid and the second portion of the fluid mix in the feed tank to form a third portion having a third temperature between the first temperature and the second temperature (col.3, l. 55-col.4, l. 13); and a fuel heat exchanger 17 coupled to the flowline, the fuel heat exchanger to receive the fluid and a fuel. Hudson is silent to a waste heat recovery heat exchanger coupled to the flowline, the waste heat recovery heat exchanger to cause the fluid to absorb heat to obtain the first temperature. Soriano teaches including a waste heat recovery heat exchanger 112 coupled to the flowline, the waste heat recovery heat exchanger to cause the fluid to absorb heat to obtain the first temperature [0018]. It would have been obvious to one of ordinary skill in the art at the time of filing to provide Hudson with the heat exchanger configuration of Soriano as Soriano teaches it helps prevent fuel freezing in storage tanks during cod environments [0005]. Regarding dependent claim 23, Hudson in view of Soriano teaches the invention as claimed and discussed above. Hudson further teaches further including fuel temperature control circuitry to increase a ratio of the first portion of the fluid to the second portion of the fluid when a fuel temperature is less than a target temperature (col.3, l. 55-col.4, l. 18). Weber teaches a flowline to carry a fluid but is silent to a closed loop. Weber teaches it was known to have a closed loop cooling system (col. 3, l. 30-43). It would have been obvious to one of ordinary skill in the art at the time of filing to provide the engine of Hudson with the closed loop cooling system of Weber, as Weber teaches improved cooling ability of the cooling system (col. 4, l. 43-49). Claim(s) 22 is/are rejected under 35 U.S.C. 103 as being unpatentable over Hudson in view of Soriano and further in view of Weber. Regarding dependent claim 22, Hudson in view of Soriano teaches the invention as claimed and discussed above. Hudson in view of Soriano is silent to wherein the flowline defines a closed-loop flow path for the fluid. Weber teaches a flowline to carry a fluid but is silent to a closed loop. Weber teaches it was known to have a closed loop cooling system (col. 3, l. 30-43). It would have been obvious to one of ordinary skill in the art at the time of filing to provide the engine of Hudson in view of Soriano with the closed loop cooling system of Weber, as Weber teaches improved cooling ability of the cooling system (col. 4, l. 43-49). 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 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

Jul 18, 2024
Application Filed
Oct 15, 2025
Non-Final Rejection — §103
Jan 02, 2026
Response Filed
Mar 10, 2026
Final Rejection — §103 (current)

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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
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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