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 .
Election/Restrictions
Applicant’s election without traverse of Species A in the reply filed on 9/25/2025 is acknowledged.
No claims have been withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected species, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 9/25/2025.
Drawings
The drawings are objected to under 37 CFR 1.83(a). The drawings must show every feature of the invention specified in the claims. Therefore, the heat exchanger of claims 4, 5 must be shown or the feature(s) canceled from the claim(s). Note element 328 is regarded as a heat exchanger. However the leadline for 328 appears to be directed to a generic part of the pylon and not to a heat exchanger. No new matter should be entered.
The drawings are objected to as failing to comply with 37 CFR 1.84(p)(5) because they include the following reference character(s) not mentioned in the description: 228 -Fig. 2.
The drawings are objected to as failing to comply with 37 CFR 1.84(p)(5) because they do not include the following reference sign(s) mentioned in the description: 311.
The drawings are objected to because Fig. 4 shows an element pylon 310 [right side] but without any leadlines to the pylon. Fig. 5 is further objected to because the fat solid arrow extending from 310 is supposed to be the fuel flow. However, the fuel flow path is unclear since 217 is supposed to be the main fuel flow conduit. Accordingly, applicant has not clearly shown the fuel flow path.
The drawings are not approved as they do not conform with the requirements of 37 CFR “1.84 Standards for drawings.”
“(l) Character of lines, numbers, and letters. All drawings must be made by a process which will give them satisfactory reproduction characteristics. Every line, number, and letter must be durable, clean, black (except for color drawings), sufficiently dense and dark, and uniformly thick and well-defined. The weight of all lines and letters must be heavy enough to permit adequate reproduction. This requirement applies to all lines however fine, to shading, and to lines representing cut surfaces in sectional views. Lines and strokes of different thicknesses may be used in the same drawing where different thicknesses have a different meaning.” The drawings are objected to because they are of poor print and line quality. Corrected drawing sheets in compliance with 37 CFR 1.121(d) are required in reply to the Office action to avoid abandonment of the application. Any amended replacement drawing sheet should include all of the figures appearing on the immediate prior version of the sheet, even if only one figure is being amended. The figure or figure number of an amended drawing should not be labeled as “amended.” If a drawing figure is to be canceled, the appropriate figure must be removed from the replacement sheet, and where necessary, the remaining figures must be renumbered and appropriate changes made to the brief description of the several views of the drawings for consistency. Additional replacement sheets may be necessary to show the renumbering of the remaining figures. Each drawing sheet submitted after the filing date of an application must be labeled in the top margin as either “Replacement Sheet” or “New Sheet” pursuant to 37 CFR 1.121(d). If the changes are not accepted by the examiner, the applicant will be notified and informed of any required corrective action in the next Office action. The objection to the drawings will not be held in abeyance.
As there are a number of issues presented in the drawings, the Examiner is requiring any replacement drawings to include a marked-up copy of any amended drawing figure.
“(2) A marked-up copy of any amended drawing figure, including annotations indicating the changes made, must be provided when required by the examiner. [From MPEP 714 citing 37 CFR 1.121(d)(2)]”
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.
Claims 12, 16 is/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.
Claim 12 “the inner anulus” lacks proper antecedent basis and is further undefined as to how an annulus is formed. Note anulus appears to be a misspelling.
Claim 16 “a propulsion system” should be –the cryogenic propulsion system—for consistency with claim 1.
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) 1-5, 7-8, 10, 11, 15, 16 is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Sibbach et al (2022/0307421). Sibbach et al teach A cryogenic fueled aircraft propulsion system comprising: a gas turbine engine 100 mounted to a wing 14 by an engine pylon 18, and configured to receive cryogenic fuel, the gas turbine engine comprising a core compressor 110; a pre-heater 224 configured to heat the fuel prior to delivery to the gas turbine engine; wherein the pre-heater 224 is located within the engine pylon 18, aft of the engine core compressor 110 [note the pylon 18 is at the aft of the engine, see Fig. 1 and thus the pre-heater is aft of compressor 110, compare Figs. 1 and 2]. (2) wherein the engine pylon 18 comprises an upper bifurcation fairing extending generally vertically from the wing 14 to a core nacelle of the gas turbine engine, and the pre-heater 224 is located within the upper bifurcation fairing. (3) wherein the pre-heater 224 comprises a burner configured to burn a portion of the fuel prior to delivery to the gas turbine engine [¶ 0037]. (4) wherein the pre-heater 224 comprises a pre-heater heat exchanger 220 configured to exchange heat between pre-heater 224 combustion gases and fuel 202 prior to delivery to the gas turbine engine. (5) wherein the pre-heater heat exchanger 220 is located within the engine pylon 18 [Fig. 4]. (6) wherein the pre-heater 224 comprises an exhaust configured to expel combustion exhaust gases. (7) wherein the pre-heater 224 comprises an air supply conduit configured to provide compressed air [bleed air, ¶ 0037] for the pre-heater 224. (8) wherein the aircraft propulsion system comprises a fuel conduit 202 configured to supply fuel to the gas turbine engine, and optionally, the pre-heater 224, wherein the fuel conduit 202 is at least partly located within the engine pylon 18. (9) wherein the fuel conduit extends through a region extending across a core gas path aft of a turbine of the gas turbine engine. (10) a recuperator 162 configured to exchange heat between exhaust gases from the gas turbine engine [from 118] and fuel prior to delivery to the gas turbine engine [e.g. ¶ 0036]. (11) wherein the recuperator 162 is located within an engine core plug nozzle 120, configured to receive turbine exhaust flow [from 118]. (15) wherein the fuel comprises one of hydrogen, methane and ammonia. (16) An aircraft comprising a propulsion system according to claim 1.
Claim(s) 1-5, 7-8, 10-11, 15, 16 is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by McCurdy Gibson (2022/0145801). McCurdy Gibson teaches A cryogenic fueled aircraft propulsion system comprising: a gas turbine engine mounted to a wing 206 by an engine pylon 208, and configured to receive cryogenic fuel, the gas turbine engine comprising a core compressor 110; a pre-heater 222 configured to heat the fuel prior to delivery to the gas turbine engine; wherein the pre-heater 222 is located within the engine pylon 208 [¶ 0073-0076], aft of the engine core compressor 110 [note the pylon 208 is at the aft of the engine, see Fig. 1 and thus the pre-heater is aft of compressor 110, compare Figs. 1 and 2]. (2) wherein the engine pylon 208 comprises an upper bifurcation fairing extending generally vertically from the wing 206 to a core nacelle of the gas turbine engine, and the pre-heater 222 is located within the upper bifurcation fairing. (3) wherein the pre-heater 222 comprises a burner 224 configured to burn a portion of the fuel prior to delivery to the gas turbine engine [¶ 0075]. (4) wherein the pre-heater 222 comprises a pre-heater heat exchanger 222 configured to exchange heat between pre-heater combustion gases and fuel prior to delivery to the gas turbine engine. (5) wherein the pre-heater heat exchanger 222 is located within the engine pylon 208. (6) wherein the pre-heater 222 comprises an exhaust configured to expel combustion exhaust gases. (7) wherein the pre-heater 222 comprises an air supply conduit configured to provide [bleed] compressed air for the pre-heater [¶ 0071]. (8) wherein the aircraft propulsion system comprises a fuel conduit 212 configured to supply fuel to the gas turbine engine, and optionally, the pre-heater 222, wherein the fuel conduit 212 is at least partly located within the engine pylon 208. (9) wherein the fuel conduit 212 extends through a region extending across a core gas path aft of a turbine of the gas turbine engine. (10) a recuperator configured to exchange heat between exhaust gases from the gas turbine engine and fuel prior to delivery to the gas turbine engine [¶ 0058]. (11) wherein the recuperator is located within an engine core plug nozzle 120, configured to receive turbine exhaust flow [¶ 0058]. (15) wherein the fuel comprises one of hydrogen, methane and ammonia. (16) An aircraft comprising a propulsion system according to claim 1.
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.
Claim(s) 1-8, 10-11, 15, 16 is/are rejected under 35 U.S.C. 103 as being unpatentable over either Sibbach et al (2022/0307421) or McCurdy Gibson (2022/0145801), as applied above, and further in view of Suciu et al (2023/0128287). As treated above, the prior art teach wherein the pre-heater is located within the engine pylon, aft of the engine core compressor; (2) wherein the engine pylon comprises an upper bifurcation fairing extending generally vertically from the wing to a core nacelle of the gas turbine engine, and the pre-heater is located within the upper bifurcation fairing. Alternately, Suciu et al may be applied to teach these limitations. Sibbach et al and McCurdy Gibson do not teach (6) ... the exhaust being directed rearwardly and located adjacent a trailing edge of the pylon. Suciu et al teach wherein the pre-heater HX1, HX2 is located within the engine pylon 12, aft of the engine core compressor 16; (2) wherein the engine pylon 12 comprises an upper bifurcation fairing 92U, BA extending generally vertically from the wing W to a core nacelle C of the gas turbine engine, and the pre-heater HX1, HX2 is located within the upper bifurcation fairing [¶ 0030]; the exhaust being directed rearwardly and located adjacent a trailing edge of the pylon 208. (4) wherein the pre-heater comprises a pre-heater heat exchanger HX1, HX2 configured to exchange heat between pre-heater gases and fuel prior to delivery to the gas turbine engine. (5) wherein the pre-heater heat exchanger HX1, HX2 is located within the engine pylon 12. (6) wherein the pre-heater HX1, HX2 comprises an exhaust 96 configured to expel pre-heater exhaust gases, the exhaust 96 being directed rearwardly and located adjacent a trailing edge 96 of the pylon.
Suciu et al teach the pre-heater arrangement for the fuel and pylon allows guiding the flow with higher aerodynamic efficiency and compactness [¶ 0035]. It would have been obvious to one of ordinary skill in the art to employ wherein the pre-heater is located within the engine pylon, aft of the engine core compressor; (2) wherein the engine pylon comprises an upper bifurcation fairing extending generally vertically from the wing to a core nacelle of the gas turbine engine, and the pre-heater is located within the upper bifurcation fairing; (5) wherein the pre-heater heat exchanger is located within the engine pylon; (6) wherein the pre-heater comprises an exhaust configured to expel combustion exhaust gases, the exhaust being directed rearwardly and located adjacent a trailing edge of the pylon, in the manner taught by Suciu et al, as a typical practical embodiment of the pre-heater / heat exchanger located within the pylon, that is taught schematically by Sibbach et al and McCurdy Gibson, and which facilitates exhausting the pre-heater combustion gases from the pre-heater.
Claim(s) 7 is/are rejected under 35 U.S.C. 103 as being unpatentable over either Sibbach et al (2022/0307421) or McCurdy Gibson (2022/0145801) with or without Suciu et al (2023/0128287), as applied above, and further in view of Palmer (2022/0099020). The prior art already teach (7) wherein the pre-heater comprises an air supply conduit configured to provide [bleed] compressed air for the pre-heater, where bleed air is regarded as compressed air. Alternately, Palmer teaches bleed air 304 is compressed air [¶ 0026, 0062] because pressurized/compressed air is used to ensure air delivery in a gas turbine engine. To the extent not already inherent, it would have been obvious to make the bleed air of Sibbach et al or McCurdy Gibson, compressed bleed air, as typically done in a gas turbine engine to ensure air delivery in a gas turbine engine.
Claim(s) 9-14 is/are rejected under 35 U.S.C. 103 as being unpatentable over either Sibbach et al (2022/0307421) or McCurdy Gibson (2022/0145801) with or without Suciu et al (2023/0128287), as applied above, and further in view of Short (3,734,639) and for claim 12 and dependents further in view of Johnson et al (2012/0227371). The prior art do not teach (9) wherein the fuel conduit extends through a tail bearing strut [vs. a region in the Sibbach et al and McCurdy Gibson references] extending across a core gas path aft of a turbine of the gas turbine engine. (12) wherein the fuel conduit comprises an inner conduit configured to flow fuel to the recuperator heat exchanger, and an outer conduit surrounding the inner conduit configured to insulate fuel in the inner anulus. (13) wherein the outer conduit is configured to provide fuel heated by the recuperator heat exchanger to a combustor of the gas turbine engine. (14) wherein the fuel conduit comprises an inlet conduit extending through a first tail bearing strut and configured to supply fuel to the recuperator, and an outlet conduit extending through a second tail bearing strut and configured to supply heated fuel to a gas turbine engine combustor.
Short teaches (9) wherein the fuel conduit extends through a tail bearing strut 18 extending across a core gas path aft of a turbine 63 of the gas turbine engine. (10) a recuperator [includes 18, 59] configured to exchange heat between exhaust gases from the gas turbine engine and fuel [fuel is used for coolant and is vaporized / heated] prior to delivery to the gas turbine engine. (11) wherein the recuperator 59 is located within an engine core plug nozzle 15, 17, configured to receive turbine exhaust flow. (12) wherein the fuel conduit comprises an inner conduit 54 configured to return fuel from the recuperator heat exchanger 59, and an outer conduit 55 surrounding the inner conduit configured to insulate fuel in the inner anulus. (13) wherein the return conduit is configured to provide fuel 34 heated by the recuperator heat exchanger to a combustor 11 of the gas turbine engine. (14) wherein the fuel conduit comprises an inlet conduit 18 extending through a first tail bearing 21 strut [Fig. 3] and configured to supply fuel to the recuperator 59, and an outlet conduit 54 extending through a second tail bearing strut [note there are multiple struts 18 and a different strut 18 from the first strut also returns the fuel] and configured to supply heated fuel 4 to a gas turbine engine combustor. Short teaches the fuel supplied to the recuperator recovers heat and provides cooling of hot plug nozzle as well as enhances engine efficiency by recovering waste heat [see col. 1, lines 14-20; col. 5, lines 43-48]. Johnson et al teach where (12) wherein the fluid conduit comprises an inner conduit 50 configured to flow fluid to the recuperator heat exchanger 82, 80, and an outer conduit 53 surrounding the inner conduit 80 configured to insulate fluid in the inner anulus. Johnson et al teach the equivalence of the inner conduit supplying the fluid to the recuperator and the outer conduit being the return to the converse arrangement where the outer conduit is supplying the fluid to the recuperator and the outer conduit being the return [see middle of ¶ 0052].
[¶ 0052 teaches “… such that the passages 52 and 53 are isolated one inside another (e.g., coaxial). The two passages 52 and 54 provide bi-directional airflow between the inner and outer structures 38 and 42. For example, the passage 52 may direct the airflow inwardly from the outer structure 42 to the inner structure 38 while the passage 53 directs the airflow from the inner structure 38 to the outer structure 42, or vice versa”
Note the converse [vice versa] arrangement is what is shown by Short. Johnson et al teach that reversing the inner conduit to be the inlet and the outer conduit to be the outlet / return are equivalent arrangements. Accordingly, Short modified by Johnson teaches (12) wherein the fuel conduit comprises an inner conduit 54 [of Short] configured to flow fuel to the recuperator heat exchanger, and an outer conduit 55 [of Short] surrounding the inner conduit configured to insulate fuel in the inner anulus. It would have been obvious to one of ordinary skill in the art to employ (9) wherein the fuel conduit extends through a tail bearing strut extending across a core gas path aft of a turbine of the gas turbine engine; and (10) a recuperator configured to exchange heat between exhaust gases from the gas turbine engine and fuel prior to delivery to the gas turbine engine; and (11) wherein the recuperator is located within an engine core plug nozzle, configured to receive turbine exhaust flow; and (14) wherein the fuel conduit comprises an inlet conduit extending through a first tail bearing strut and configured to supply fuel to the recuperator, and an outlet conduit extending through a second tail bearing strut and configured to supply heated fuel to a gas turbine engine combustor, as taught by Short, in order to recover heat and provides cooling of hot plug nozzle as well as enhances engine efficiency. It would have been obvious to one of ordinary skill in the art to employ (12) wherein the fuel conduit comprises an inner conduit configured to flow fuel to the recuperator heat exchanger, and an outer conduit surrounding the inner conduit configured to insulate fuel in the inner anulus; (13) wherein the outer conduit is configured to provide fuel heated by the recuperator heat exchanger to a combustor of the gas turbine engine, as taught by Short and Johnson, where Johnson et al [see ¶ 0053 quoted above] teach making the inner conduit configured to flow fuel to the recuperator heat exchanger, and an outer conduit surrounding the inner conduit configured to insulate fuel in the inner anulus, are equivalent arrangements to that illustrated by Short, so as to effectively recover heat and provides cooling of hot plug nozzle as well as enhances engine efficiency in the manner taught by Short.
Contact Information
Any inquiry concerning this communication or earlier communications from the Examiner should be directed to TED KIM whose telephone number is 571-272-4829. The Examiner can be reached on regular business hours before 5:00 pm, Monday to Thursday and every other Friday.
The fax number for the organization where this application is assigned is 571-273-8300.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Devon Kramer, can be reached at 571-272-7118. Alternate inquiries to Technology Center 3700 can be made via 571-272-3700.
Information regarding the status of an application may be obtained from Patent Center https://www.uspto.gov/patents/apply/patent-center. Should you have questions on Patent Center, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). General inquiries can also be directed to the Inventors Assistance Center whose telephone number is 800-786-9199. Furthermore, a variety of online resources are available at https://www.uspto.gov/patent
/Ted Kim/
Telephone
571-272-4829
Primary Examiner
Fax
571-273-8300
November 18, 2025