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 .
Response to Amendment
This office action is responsive to the amendment filed 11/25/2025 for application 18519465. Claims 11-12 are canceled by Applicant. Claims 1-10 & 13-20 are pending.
Claim Objections
Claim 16 is objected to because of the following informalities:
The recitation “an environment external to the aircraft” (ll. 10-11) is believed to be in error for - - the environment external to the aircraft - -.
Appropriate correction is required.
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.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1-8, 10, 15, & 20 are rejected under 35 U.S.C. 103 as being unpatentable over Boucher 20210340908 in view of Terwilliger 20220397062. Regarding Independent Claim 1, Boucher teaches a system (Fig. 3) for an aircraft,
comprising:
an engine (308/310/312/314/316);
a fuel system including a fuel circuit (326), a fuel source (322), a heat exchanger (332) and a turboexpander (334), the fuel circuit configured to direct fuel in a liquid phase from the fuel source (para. [0042]), through the heat exchanger and the turboexpander (through 332 and 334), to the engine for combustion (at 312), the fuel being in a gaseous phase when the fuel exits the heat exchanger (the fuel is in a gaseous phase when exiting 332 as it then flows through turbine 334), and the heat exchanger configured to transfer heat energy from combustion products generated by the combustion of the fuel in the engine into the fuel in the fuel circuit (para. [0044]);
an air system discrete from the engine (334/336, discrete from the engine), the air system including an air compressor (fan driven by 336 – note that while called a “fan” it is clear that this fan is not for propulsion but rather for providing air to some unspecified system onboard the engine or aircraft, but either way the air on which this fan acts would be pressurized to some extent given that this is what fans do, they inherently create a pressure differential during operation causing air to flow from upstream of the fan to downstream of the fan, but one of ordinary skill in the art would recognize this turbine-driven “fan” is actually a compressor for unspecified onboard use; para. [0045]) and the turboexpander (334), and the air system configured to expand the fuel directed across the turboexpander by the fuel circuit to power operation of the air compressor (para. [0045]);
an engine inlet fluidly coupling the engine to an environment external to the aircraft (inlet for 308); and
an air circuit inlet fluidly coupling the air compressor to the environment external to the aircraft (inlet to fan driven by 336)
wherein the engine inlet and the air circuit inlet are each fluidly coupled to the environment external to the aircraft (the inlets to the engine and the fan driven by 336 are each fluidly coupled to the environment).
Boucher fails to expressly teach the engine inlet and the air circuit inlet independently fluidly coupled to the environment external to the aircraft.
Terwilliger teaches (Fig. 2) a system for an aircraft (Fig. 1) with a core engine having a fan and compressor (42 and 44/52, respectively) and a separate auxiliary fan (60) which is not driven by the core engine (see electric motor 84 which drives auxiliary compressor 60). The auxiliary compressor can receive air from a bypass flow path, may be RAM air from outside the gas turbine engine, or fluid flow from another engine or aircraft system (para. [0037]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Boucher’s system such that the air circuit inlet (providing air to the air compressor) is provided RAM air from outside the gas turbine engine, as taught by Terwilliger, because a) the prior art contained a device which differed from the claimed device by the substitution of some components with other components (Boucher’s air circuit inlet coupled to the environment external to the aircraft via some unspecified path versus the claimed arrangement with the air circuit inlet coupled to the environment external to the aircraft independently from the engine inlet, as taught by Terwilliger with respect to RAM air provision to an auxiliary compressor), b) the substituted components and their functions were known in the art (both Boucher’s and Terwilliger’s arrangements were known for providing air to an auxiliary compressor/fan), and c) one of ordinary skill in the art could have substituted one known element for another and the results of the substitution would have been predictable (either Boucher’s arrangement providing air from the environment external to the aircraft via an unspecified pathway to a compressor or Terwilliger’s arrangement providing RAM air to a fan could have been used to predictably provide air for an auxiliary compressor/fan to perform work on, as evidenced by Terwilliger’s teaching of various sources of air for such a compressor/fan including from bypass air, RAM air, or air from another engine or aircraft system). It has been held that “when a patent claims a structure already known in the prior art that is altered by the mere substitution of one element for another known in the field, the combination must do more than yield a predictable result.” KSR International Co. v. Teleflex Inc., et al., 82 USPQ2d 1385, 1395 (2007) (citing United States v. Adams, 383 US 39, 50-51 (1966)). See MPEP 2143 I(B). The proposed modification of Boucher with Terwilliger results in the air circuit inlet and the engine inlet each being independently fluidly coupled to the environment external to the aircraft.
Regarding Dependent Claim 2, Boucher in view of Terwilliger teaches the invention as claimed and as discussed above for claim 1, and Boucher further teaches the fuel comprises hydrogen fuel (para. [0042]); and the fuel source comprises a hydrogen fuel reservoir (322).
Regarding Dependent Claim 3, Boucher in view of Terwilliger teaches the invention as claimed and as discussed above for claim 1, and Boucher further teaches the fuel system is configured to store the fuel within the fuel source as a cryogenic liquid (para. [0042]).
Regarding Dependent Claim 4, Boucher in view of Terwilliger teaches the invention as claimed and as discussed above for claim 1, and Boucher further teaches the heat exchanger is configured to facilitate changing the fuel from the liquid phase to the gaseous phase (see discussion for claim 1 above; para. [0044]); and the air system is configured to expand the fuel in the gaseous phase across the turboexpander before delivering the fuel in the gaseous phase to the engine (expanded across 334 before delivering fuel in gaseous phase to 312).
Regarding Dependent Claim 5, Boucher in view of Terwilliger teaches the invention as claimed and as discussed above for claim 1, and Boucher further teaches the engine comprises a gas turbine engine (308/310/312/314/316).
Regarding Dependent Claim 6, Boucher in view of Terwilliger teaches the invention as claimed and as discussed above for claim 1, and Boucher further teaches the engine includes a compressor section (308/310), a combustor section (312), a turbine section (314/316) and a flowpath (C) extending through the compressor section, the combustor section and the turbine section from an inlet into the flowpath to an exhaust from the flowpath (from inlet at 308 to exhaust at 318); and the heat exchanger is arranged along the flowpath between the combustor section and the exhaust from the flowpath (332 between 312 and 318).
Regarding Dependent Claim 7, Boucher in view of Terwilliger teaches the invention as claimed and as discussed above for claim 6, and Boucher further teaches the heat exchanger is arranged along the flowpath between the turbine section and the exhaust from the flowpath (332 between 314/316 and 318).
Regarding Dependent Claim 8, Boucher in view of Terwilliger teaches the invention as claimed and as discussed above for claim 1, and Boucher further teaches a pneumatic system including an air circuit (inherent to provision of a fan, the pneumatic system includes an air circuit for ducting air from the fan), the pneumatic system configured to receive compressed air through the air circuit from the air compressor (inherent to air circuit ducting).
Regarding Dependent Claim 10, Boucher in view of Terwilliger teaches the invention as claimed and as discussed above for claim 1, and Boucher in view of Terwilliger teaches, as discussed above for claim 1, the air compressor is fluidly decoupled from the engine (fan driven by 336 is fluidly decoupled from 308/310/312/314/316 at least due to receiving RAM air, as discussed for claim 1 above, separate from the air received at the engine inlet).
Regarding Dependent Claim 15, Boucher in view of Terwilliger teaches the invention as claimed and as discussed above for claim 1, and Boucher further teaches a propulsor rotor (304) coupled to and configured to be driven by the engine.
Regarding Independent Claim 20, Boucher teaches a system (Fig. 3) for an aircraft, comprising:
a gas turbine engine (308/310/312/314/316) including a compressor section (308/310), a combustor section (312), a turbine section (314/316) and a flowpath extending through the compressor section, the combustor section and the turbine section from an engine inlet into the flowpath to an exhaust from the flowpath (flowpath C through each of 308/310/312/314/316 from inlet of engine to exhaust at 318), the engine inlet fluidly coupling the gas turbine engine to an environment external to the aircraft (engine inlet receives air from the external environment);
a fuel system configured to deliver fuel to the combustor section, the fuel system including a fuel circuit (326), a fuel source (322), a heat exchanger (332) and a turboexpander (334), the fuel circuit fluidly coupling the fuel source to the combustor section (from 322 to 312), and the fuel circuit extending sequentially through the heat exchanger, the turboexpander between the fuel source and the combustor section, and to the combustor section (326 extends sequentially through 332, 334 between 322 and 312, and to 312); and
an air system including an air compressor (fan driven by 336 – note that while called a “fan” it is clear that this fan is not for propulsion but rather for providing air to some unspecified system onboard the engine or aircraft, but either way the air on which this fan acts would be pressurized to some extent given that this is what fans do, they inherently create a pressure differential during operation causing air to flow from upstream of the fan to downstream of the fan, but one of ordinary skill in the art would recognize this turbine-driven “fan” is actually a compressor for unspecified onboard use; para. [0045]) and the turboexpander, the air compressor fluidly independent of the flowpath (fan driven by 336 is fluidly independent of flowpath C), and a turboexpander rotor in the turboexpander coupled to and configured to drive rotation of an air compressor rotor in the air compressor (rotor in 334 which drives 336 to rotate rotor in fan; para. [0045]), the air compressor comprising an air compressor inlet fluidly coupling the air compressor to the environment external to the aircraft (the inlet of the fan driven by 336 is fluidly coupled to the environment external to the aircraft in some way);
wherein the fuel system is configured such that the heat exchanger provides the fuel to the turboexpander as warm and high pressure gaseous fuel (para. [0045]), and the turboexpander expands the warm and high pressure gaseous fuel to provide low pressure gaseous fuel (fuel expanded in 334 will inherently have a lower pressure than fuel entering 334);
wherein the fuel system is further configured to deliver the low pressure gaseous fuel to one or more fuel injectors in the combustor section (para. [0045]);
wherein the engine inlet and the air compressor inlet are each fluidly coupled to the environment external to the aircraft (each of the engine inlet and the air compressor inlet are fluidly coupled to the environment external to the aircraft via some pathway(s)).
Boucher fails to expressly teach the engine inlet and the air compressor inlet are each separately fluidly coupled to the environment external to the aircraft.
Terwilliger teaches (Fig. 2) a system for an aircraft (Fig. 1) with a core engine having a fan and compressor (42 and 44/52, respectively) and a separate auxiliary fan (60) which is not driven by the core engine (see electric motor 84 which drives auxiliary compressor 60). The auxiliary compressor can receive air from a bypass flow path, may be RAM air from outside the gas turbine engine, or fluid flow from another engine or aircraft system (para. [0037]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Boucher’s system such that the air circuit inlet (providing air to the air compressor) is provided RAM air from outside the gas turbine engine, as taught by Terwilliger, because a) the prior art contained a device which differed from the claimed device by the substitution of some components with other components (Boucher’s air circuit inlet coupled to the environment external to the aircraft via some unspecified path versus the claimed arrangement with the air circuit inlet coupled to the environment external to the aircraft independently from the engine inlet, as taught by Terwilliger with respect to RAM air provision to an auxiliary compressor), b) the substituted components and their functions were known in the art (both Boucher’s and Terwilliger’s arrangements were known for providing air to an auxiliary compressor/fan), and c) one of ordinary skill in the art could have substituted one known element for another and the results of the substitution would have been predictable (either Boucher’s arrangement providing air from the environment external to the aircraft via an unspecified pathway to a compressor or Terwilliger’s arrangement providing RAM air to a fan could have been used to predictably provide air for an auxiliary compressor/fan to perform work on, as evidenced by Terwilliger’s teaching of various sources of air for such a compressor/fan including from bypass air, RAM air, or air from another engine or aircraft system). It has been held that “when a patent claims a structure already known in the prior art that is altered by the mere substitution of one element for another known in the field, the combination must do more than yield a predictable result.” KSR International Co. v. Teleflex Inc., et al., 82 USPQ2d 1385, 1395 (2007) (citing United States v. Adams, 383 US 39, 50-51 (1966)). See MPEP 2143 I(B). The proposed modification of Boucher with Terwilliger results in the engine inlet and the air compressor inlet each being separately fluidly coupled to the environment external to the aircraft.
Claim 9 is rejected under 35 U.S.C. 103 as being unpatentable over Boucher in view of Terwilliger, as applied to claim 8 above, and further in view of Fukuchi 20240318596.
Regarding Dependent Claim 9, Boucher in view of Terwilliger teaches the invention as claimed and as discussed above for claim 8, but Boucher in view of Terwilliger fails to teach the pneumatic system includes a bleed air circuit, the pneumatic system is configured to receive additional compressed air from the bleed circuit fluidly coupled to the engine.
Fukuchi teaches a pneumatic system (22/102) which is configured to receive compressed air from an air compressor (air pump 104) and from a bleed circuit fluidly coupled to an engine (bleed path 22 coupled to compressor 28; para. [0039]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Boucher in view of Terwilliger’s system such that the pneumatic system includes a bleed air circuit, the pneumatic system is configured to receive additional compressed air from a bleed circuit fluidly coupled to the engine, as taught by Fukuchi, in order to ensure a minimum flow of compressed air to a pneumatic system configured to cool and seal bearings of a rotating electric machine (Fukuchi; para. [0076]).
Claims 13-14 are rejected under 35 U.S.C. 103 as being unpatentable over Boucher in view of Terwilliger, as applied to claim 1 above, and further in view of Schwarz 20170268430.
Regarding Dependent Claim 13, Boucher in view of Terwilliger teaches the invention as claimed and as discussed above for claim 1, and Boucher further teaches a nacelle housing the engine (a nacelle defining exterior of core in Fig. 1 over which bypass air B flows).
Boucher in view of Terwilliger fails to teach the air compressor is located outside of the nacelle.
Schwarz teaches a turboexpander (connected with turbo-compressor 60, thus 60 is considered the “turboexpander” as a whole) which may be located within a pylon (84) or in an aircraft (turbo-compressor 60 is within pylon 84 or in aircraft 5; para. [0038]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Boucher in view of Terwilliger’s system such that the air compressor is located outside of the nacelle, as taught by Schwarz, because the location of the turboexpander, whether within the nacelle or outside of it, would not have modified operation of the device and would have been an obvious matter of design choice. In re Japikse, 181 F.2d 1019, 86 USPQ 70 (CCPA 1950). In re Kuhle, 526 F.2d 553, 188 USPQ 7 (CCPA 1975). See MPEP 2144.04 VI (C).
Regarding Dependent Claim 14, Boucher in view of Terwilliger teaches the invention as claimed and as discussed above for claim 1, and Boucher further teaches a nacelle housing the engine (a nacelle defining exterior of core in Fig. 1 over which bypass air B flows, nacelle 15 defining bypass duct).
Boucher in view of Terwilliger fails to teach the air compressor is housed by the nacelle.
Schwarz teaches a turboexpander (connected with turbo-compressor 60, thus 60 is considered the “turboexpander” as a whole) which may be located within a pylon (84) or in an aircraft (turbo-compressor 60 is within pylon 84 or in aircraft 5; para. [0038]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Boucher in view of Terwilliger’s system such that the air compressor is housed by the nacelle, as taught by Schwarz, because the location of the turboexpander, whether within the nacelle or outside of it, would not have modified operation of the device and would have been an obvious matter of design choice. In re Japikse, 181 F.2d 1019, 86 USPQ 70 (CCPA 1950). In re Kuhle, 526 F.2d 553, 188 USPQ 7 (CCPA 1975). See MPEP 2144.04 VI (C).
Claim 20 is rejected under 35 U.S.C. 103 as being unpatentable over Clark 20230280032 in view of Terwilliger.
Regarding Independent Claim 20, Clark teaches a system (Fig. 4A) for an aircraft (para. [0005]), comprising:
a gas turbine engine (103) including a compressor section (304/305), a combustor section (306), a turbine section (307/308) and a flowpath extending through the compressor section, the combustor section and the turbine section from an engine inlet into the flowpath to an exhaust from the flowpath (flowpath extending from inlet at C through 304/305, 306, 307/308 to exhaust at 311, incorrectly shown as 310 in Fig. 4A), the engine inlet fluidly coupling the gas turbine engine to an environment external to the aircraft (inlet at C fluidly couples the gas turbine engine to the environment external to the aircraft);
a fuel system configured to deliver fuel to the combustor section, the fuel system including a fuel circuit (fuel line extending from “FUEL IN”), a fuel source (Fig. 1, cryogenic storage system 104), a heat exchanger (403) and a turboexpander (404), the fuel circuit fluidly coupling the fuel source to the combustor section (via 403, 404, and 406), and the fuel circuit extending sequentially through the heat exchanger, the turboexpander between the fuel source and the combustor section, and to the combustor section (from 104 to 306, the fuel circuit extends sequentially through 403, 404 between 104 and 306, and to 306); and
an air system including an air compressor (turboexpander can drive an air compressor; para. [0073]) and the turboexpander (404), the air compressor fluidly independent of the flowpath (air compressor driven by 404 is used to supply air to pneumatic system such as anti-ice systems and is fluidly independent from the core flow path through 304/305, 306, 307/308), and a turboexpander rotor in the turboexpander coupled to and configured to drive rotation of an air compressor rotor in the air compressor (para. [0073]), the air compressor comprising an air compressor inlet fluidly coupling the air compressor to the environment external to the aircraft (air compressor driven by 404 is fluidly coupled to the environment external to the aircraft via some unspecified pathway);
wherein the fuel system is configured such that the heat exchanger provides the fuel to the turboexpander as warm and high pressure gaseous fuel (warm and high pressure gaseous fuel provided from 403 to 404), and the turboexpander expands the warm and high pressure gaseous fuel to provide low pressure gaseous fuel (lower pressure fuel provided at outlet of 404);
wherein the fuel system is further configured to deliver the low pressure gaseous fuel to one or more fuel injectors in the combustion section (the lower pressure gaseous fuel from 404 is delivered to fuel injectors in 306; para. [0074]);
wherein the engine inlet and the air compressor inlet are each fluidly coupled to the environment external to the aircraft (the engine inlet at C and the inlet to the air compressor driven by 404 are each fluidly coupled to the environment external to the aircraft via at least one pathway).
Clark fails to expressly teach the engine inlet and the air compressor inlet are each separately fluidly coupled to the environment external to the aircraft.
Terwilliger teaches (Fig. 2) a system for an aircraft (Fig. 1) with a core engine having a fan and compressor (42 and 44/52, respectively) and a separate auxiliary fan (60) which is not driven by the core engine (see electric motor 84 which drives auxiliary compressor 60). The auxiliary compressor can receive air from a bypass flow path, may be RAM air from outside the gas turbine engine, or fluid flow from another engine or aircraft system (para. [0037]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Clark’s system such that the air circuit inlet (providing air to the air compressor) is provided RAM air from outside the gas turbine engine, as taught by Terwilliger, because a) the prior art contained a device which differed from the claimed device by the substitution of some components with other components (Clark’s air circuit inlet coupled to the environment external to the aircraft via some unspecified path versus the claimed arrangement with the air circuit inlet coupled to the environment external to the aircraft independently from the engine inlet, as taught by Terwilliger with respect to RAM air provision to an auxiliary compressor), b) the substituted components and their functions were known in the art (both Clark’s and Terwilliger’s arrangements were known for providing air to an auxiliary compressor/fan), and c) one of ordinary skill in the art could have substituted one known element for another and the results of the substitution would have been predictable (either Clark’s arrangement providing air from the environment external to the aircraft via an unspecified pathway to a compressor or Terwilliger’s arrangement providing RAM air to a fan could have been used to predictably provide air for an auxiliary compressor/fan to perform work on, as evidenced by Terwilliger’s teaching of various sources of air for such a compressor/fan including from bypass air, RAM air, or air from another engine or aircraft system). It has been held that “when a patent claims a structure already known in the prior art that is altered by the mere substitution of one element for another known in the field, the combination must do more than yield a predictable result.” KSR International Co. v. Teleflex Inc., et al., 82 USPQ2d 1385, 1395 (2007) (citing United States v. Adams, 383 US 39, 50-51 (1966)). See MPEP 2143 I(B). The proposed modification of Clark with Terwilliger results in the engine inlet and the air compressor inlet each being separately fluidly coupled to the environment external to the aircraft.
Claims 1-8, 10, & 14-15 are rejected under 35 U.S.C. 103 as being unpatentable over Razak 20160123226 in view of Clark and further in view of Terwilliger.
Regarding Independent Claim 1, Razak teaches a system (Fig. 2) for an aircraft (para. [0046]) comprising:
an engine (10);
a fuel system including a fuel circuit (extending from 27 through 32, 33 and to 15), a fuel source (27), a heat exchanger (32) and a turboexpander (33), the fuel circuit configured to direct fuel from the fuel source in a liquid phase (fuel pumped from 27 is in a liquid phase; para. [0056]), through the heat exchanger and the turboexpander, to the engine for combustion (see fuel path from 27, through 32, through 33, to 15), the fuel being in a gaseous phase when the fuel exits the heat exchanger (para. [0059]), and the heat exchanger configured to transfer heat energy from combustion products generated by the combustion of the fuel in the engine into the fuel in the fuel circuit (para. [0058]);
an engine inlet fluidly coupling the engine to an environment external to the aircraft (Razak’s inlet 11 couples 10 to external environment).
While Razak’s figures show the turboexpander powering the same load (26) as the engine’s turbine section, Razak teaches that the turboexpander could instead be used to power drive other loads (para. [0061]).
Razak fails to teach an air system discrete from the engine, the air system including an air compressor and the turboexpander, the air system configured to expand the fuel directed across the turboexpander by the fuel circuit to power operation of the air compressor, an air circuit inlet fluidly coupling the air compressor to the environment external to the aircraft.
Clark teaches a system (Fig. 4A) for an aircraft (Fig. 1), comprising an engine (103), a fuel system with a fuel circuit passing fuel from a fuel source (104) through a heat exchanger (403) and a turboexpander (404) to the engine for combustion (in 306), and an air system discrete from the engine (the air system which follows is not part of the core engine itself), the air system including an air compressor and the turboexpander (turboexpander 404 can drive an air compressor; para. [0073]), the air system configured to expand fuel directed across the turboexpander by the fuel circuit to power operation of the air compressor (para. [0073]), an air circuit inlet fluidly coupling the air compressor to the environment external to the aircraft (an inlet will provide fluid communication between the air compressor driven by 404 and the environment external to the aircraft).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Razak’s system to include an air system discrete from the engine, the air system including an air compressor and the turboexpander, and the air system configured to expand the fuel directed across the turboexpander by the fuel circuit to power operation of the air compressor, and an air circuit inlet fluidly coupling the air compressor to the environment external to the aircraft, as taught by Clark, in order to develop work from the heated fuel and use that work to provide compressed air to systems such as anti-ice systems or for cabin air (Clark; para. [0073]).
Razak in view of Clark fails to expressly teach the engine inlet and the air circuit inlet are each independently fluidly coupled to the environment external to the aircraft.
Terwilliger teaches (Fig. 2) a system for an aircraft (Fig. 1) with a core engine having a fan and compressor (42 and 44/52, respectively) and a separate auxiliary fan (60) which is not driven by the core engine (see electric motor 84 which drives auxiliary compressor 60). The auxiliary compressor can receive air from a bypass flow path, may be RAM air from outside the gas turbine engine, or fluid flow from another engine or aircraft system (para. [0037]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Razak in view of Clark’s system such that the air circuit inlet (providing air to the air compressor) is provided RAM air from outside the engine, as taught by Terwilliger, because a) the prior art contained a device which differed from the claimed device by the substitution of some components with other components (Razak in view of Clark’s air circuit inlet coupled to the environment external to the aircraft via some path versus the claimed arrangement with the air circuit inlet coupled to the environment external to the aircraft independently from the engine inlet, as taught by Terwilliger with respect to RAM air provision to an auxiliary compressor), b) the substituted components and their functions were known in the art (both Razak in view of Clark’s and Terwilliger’s arrangements were known for providing air to an auxiliary compressor/fan), and c) one of ordinary skill in the art could have substituted one known element for another and the results of the substitution would have been predictable (either Razak in view of Clark’s arrangement providing air from the environment external to the aircraft via an unspecified pathway to a compressor or Terwilliger’s arrangement providing RAM air to a fan could have been used to predictably provide air for an auxiliary compressor/fan to perform work on, as evidenced by Terwilliger’s teaching of various sources of air for such a compressor/fan including from bypass air, RAM air, or air from another engine or aircraft system). It has been held that “when a patent claims a structure already known in the prior art that is altered by the mere substitution of one element for another known in the field, the combination must do more than yield a predictable result.” KSR International Co. v. Teleflex Inc., et al., 82 USPQ2d 1385, 1395 (2007) (citing United States v. Adams, 383 US 39, 50-51 (1966)). See MPEP 2143 I(B). The proposed modification of Razak in view of Clark with Terwilliger results in the engine inlet and the air circuit inlet each being independently fluidly coupled to the environment external to the aircraft.
Regarding Dependent Claim 2, Razak in view of Clark further in view of Terwilliger teaches the invention as claimed and as discussed above for claim 1, and Razak further teaches the fuel comprises hydrogen fuel (para. [0054]); and the fuel source comprises a hydrogen fuel reservoir (tank 27; para. [0054]).
Regarding Dependent Claim 3, Razak in view of Clark further in view of Terwilliger teaches the invention as claimed and as discussed above for claim 1, and Razak further teaches the fuel system is configured to store the fuel within the fuel source as a cryogenic liquid (para. [0054]).
Regarding Dependent Claim 4, Razak in view of Clark further in view of Terwilliger teaches the invention as claimed and as discussed above for claim 1, and Razak further teaches the fuel source is configured to direct the fuel into the fuel circuit in a liquid phase (para. [0054]); the heat exchanger is configured to facilitate changing the fuel from the liquid phase to a gaseous phase (32 is capable of facilitating the change of fuel from liquid to gaseous, since any liquid fuel present in the fuel line extending through 32 will be vaporized due to the exhaust gases heating it; alternatively, the heat exchanger can be reinterpreted for the instant claim as 30, which is expressly taught as vaporizing the fuel during normal operation – this additional interpretation of Razak does not change any of the rest of elements from Razak which read on claim 1); and the air system is configured to expand the fuel in the gaseous phase across the turboexpander before delivering the fuel in the gaseous phase to the engine (para. [0059]).
Regarding Dependent Claim 5, Razak in view of Clark further in view of Terwilliger teaches the invention as claimed and as discussed above for claim 1, and Razak further teaches the engine comprises a gas turbine engine (para. [0046]).
Regarding Dependent Claim 6, Razak in view of Clark further in view of Terwilliger teaches the invention as claimed and as discussed above for claim 1, and Razak further teaches the engine includes a compressor section (14), a combustor section (15), a turbine section (25) and a flowpath extending through the compressor section, the combustor section and the turbine section from an inlet into the flowpath to an exhaust from the flowpath (flowpath from inlet at 11 through 14, 15, 25 and to exhaust nozzle 23); and the heat exchanger is arranged along the flowpath between the combustor section and the exhaust from the flowpath (32 is arranged between 15 and 23).
Regarding Dependent Claim 7, Razak in view of Clark further in view of Terwilliger teaches the invention as claimed and as discussed above for claim 6, and Razak further teaches the heat exchanger is arranged along the flowpath between the turbine section and the exhaust from the flowpath (32 is between 25 and 23).
Regarding Dependent Claim 8, Razak in view of Clark further in view of Terwilliger teaches the invention as claimed and as discussed above for claim 1, and Clark further teaches a pneumatic system including an air circuit, the pneumatic system configured to receive compressed air through the air circuit from the air compressor (pneumatic lines, i.e. the air circuit, are inherent for receiving compressed air from the air compressor for delivery to anti-ice systems or cabin air; para. [0073]).
Regarding Dependent Claim 10, Razak in view of Clark further in view of Terwilliger teaches the invention as claimed and as discussed above for claim 1, and Clark further teaches the air compressor is fluidly decoupled from the engine (air compressor driven by 404 is used to supply air to pneumatic systems such as anti-ice systems and is fluidly independent from the core flow path through 304/305, 306, 307/308).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Razak in view of Clark further in view of Terwilliger’s system such that the air compressor is fluidly decoupled from the engine, as taught by Clark, for the reasons cited above for claim 1 and because the air compressor taught by Clark, as included in the modification of Razak with Clark for claim 1 above, is not in fluid communication with the core flow path of the engine.
Regarding Dependent Claim 14, Razak in view of Clark further in view of Terwilliger teaches the invention as claimed and as discussed above for claim 1, and Razak further teaches a nacelle housing the engine (21 houses the engine core).
Clark further teaches a nacelle (Fig. 3, nacelle 302) housing the engine and the air compressor (nacelle houses the core engine and the turboexpander 404 – see element 201 in Fig. 3 and para. [0058] – and since the turboexpander drives the air compressor, the air compressor must be co-located with the turboexpander and also housed in the nacelle).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Razak in view of Clark further in view of Terwilliger’s system such that the nacelle houses the air compressor, as taught by Clark, given Clark’s suggestion of locating the turboexpander in the core cowl within the nacelle and the co-location of the air compressor with the turboexpander (Clark; Fig. 3).
Regarding Dependent Claim 15, Razak in view of Clark further in view of Terwilliger teaches the invention as claimed and as discussed above for claim 1, and Razak further teaches a propulsor rotor (12) coupled to and configured to be driven by the engine (para. [0049]).
Claim 9 is rejected under 35 U.S.C. 103 as being unpatentable over Razak in view of Clark further in view of Terwilliger, as applied to claim 8 above, and further in view of Fukuchi.
Regarding Dependent Claim 9, Razak in view of Clark further in view of Terwilliger teaches the invention as claimed and as discussed above for claim 8, but Razak in view of Clark further in view of Terwilliger fails to teach the pneumatic system includes a bleed air circuit, the pneumatic system is configured to receive additional compressed air from the bleed circuit fluidly coupled to the engine.
Fukuchi teaches a pneumatic system (22/102) which is configured to receive compressed air from an air compressor (air pump 104) and from a bleed circuit fluidly coupled to an engine (bleed path 22 coupled to compressor 28; para. [0039]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Razak in view of Clark further in view of Terwilliger’s system such that the pneumatic system includes a bleed air circuit, the pneumatic system is configured to receive additional compressed air from a bleed circuit fluidly coupled to the engine, as taught by Fukuchi, in order to ensure a minimum flow of compressed air to a pneumatic system configured to cool and seal bearings of a rotating electric machine (Fukuchi; para. [0076]).
Claim 13 is rejected under 35 U.S.C. 103 as being unpatentable over Razak in view of Clark further in view of Terwilliger, as applied to claim 1 above, and further in view of Schwarz.
Regarding Dependent Claim 13, Razak in view of Clark further in view of Terwilliger teaches the invention as claimed and as discussed above for claim 1, and Razak further teaches a nacelle housing the engine (nacelle 21 houses the engine core).
Razak in view of Clark further in view of Terwilliger fails to teach the air compressor is located outside of the nacelle.
Schwarz teaches a turboexpander (connected with turbo-compressor 60, thus 60 is considered the “turboexpander” as a whole) which may be located within a pylon (84) or in an aircraft (turbo-compressor 60 is within pylon 84 or in aircraft 5; para. [0038]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Razak in view of Clark further in view of Terwilliger’s system such that the air compressor is located outside of the nacelle, as taught by Schwarz, because the location of the turboexpander, whether within the nacelle or outside of it, would not have modified operation of the device and would have been an obvious matter of design choice. In re Japikse, 181 F.2d 1019, 86 USPQ 70 (CCPA 1950). In re Kuhle, 526 F.2d 553, 188 USPQ 7 (CCPA 1975). See MPEP 2144.04 VI (C).
Claims 16-17 & 19 are rejected under 35 U.S.C. 103 as being unpatentable over Boucher in view of Clark further in view of Terwilliger.
Regarding Independent Claim 16, Boucher teaches a system (Fig. 3) for an aircraft, comprising:
an engine (308/310/312/314/316);
an engine inlet fluidly coupling the engine to an environment external to the aircraft (inlet to 308);
an air system including an air compressor (fan and associated ducting, the fan driven by 336 – note that while called a “fan” it is clear that this fan is not for propulsion but rather for providing air to some unspecified system onboard the engine or aircraft, but either way the air on which this fan acts would be pressurized to some extent given that this is what fans do, they inherently create a pressure differential during operation causing air to flow from upstream of the fan to downstream of the fan, but one of ordinary skill in the art would recognize this turbine-driven “fan” is actually a compressor for unspecified onboard use; para. [0045]) and a turboexpander (334), the air system configured to expand fuel directed across the turboexpander to power operation of the air compressor (para. [0045]);
an air system inlet fluidly coupling the air compressor to the environment external to the aircraft (the air system inherently has an inlet coupling the fan driven by 336 to the environment external to the aircraft, the pathway to the environment external to the aircraft being unspecified, however); and
a fuel system including a fuel circuit (326), a heat exchanger (332) and the turboexpander, the fuel circuit configured to direct the fuel through the heat exchanger to the turboexpander and to the engine for combustion (fuel flows through 332 to 334 to combustor 312), and the heat exchanger configured to increase a temperature and a pressure of the fuel (para. [0044]);
wherein the pressure of the fuel entering the turboexpander is a first pressure and the pressure of the fuel exiting the turboexpander is a second pressure less than the first pressure (pressure of fuel leaving 334 will be less than pressure of fuel entering 334); and
wherein the fuel circuit is further configured to deliver the fuel from the turboexpander to the engine for combustion at the second pressure (fuel from 334 at the second pressure is delivered to combustor 312).
Boucher fails to teach a pneumatic system, the air compressor configured to provide compressed air for delivery to the pneumatic system.
Clark teaches a system (Fig. 4A) for an aircraft (Fig. 1), comprising an engine (103), a fuel system with a fuel circuit passing fuel from a fuel source (104) through a heat exchanger (403) and a turboexpander (404) to the engine for combustion (in 306), and an air system, the air system including an air compressor and the turboexpander (turboexpander 404 can drive an air compressor; para. [0073]), the air system configured to expand fuel directed across the turboexpander by the fuel circuit to power operation of the air compressor (para. [0073]).
a pneumatic system including an air circuit, the pneumatic system configured to receive compressed air through the air circuit from the air compressor (pneumatic lines, i.e. the air circuit, are inherent for receiving compressed air from the air compressor for delivery to anti-ice systems or cabin air; para. [0073]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Boucher’s system to include a pneumatic system, the air compressor configured to provide compressed air for delivery to the pneumatic system, as taught by Clark, in order to use developed work from the heated fuel to provide compressed air to systems such as anti-ice systems or for cabin air (Clark; para. [0073]).
Boucher in view of Clark fails to expressly teach the air system inlet fluidly coupling the air compressor to the environment external to the aircraft independently from the engine inlet fluidly coupling the engine to an environment external to the aircraft.
Terwilliger teaches (Fig. 2) a system for an aircraft (Fig. 1) with a core engine having a fan and compressor (42 and 44/52, respectively) and a separate auxiliary fan (60) which is not driven by the core engine (see electric motor 84 which drives auxiliary compressor 60). The auxiliary compressor can receive air from a bypass flow path, may be RAM air from outside the gas turbine engine, or fluid flow from another engine or aircraft system (para. [0037]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Boucher in view of Clark’s system such that the air circuit inlet (providing air to the air compressor) is provided RAM air from outside the gas turbine engine, as taught by Terwilliger, because a) the prior art contained a device which differed from the claimed device by the substitution of some components with other components (Boucher in view of Clark’s air circuit inlet coupled to the environment external to the aircraft via some unspecified path versus the claimed arrangement with the air circuit inlet coupled to the environment external to the aircraft independently from the engine inlet, as taught by Terwilliger with respect to RAM air provision to an auxiliary compressor), b) the substituted components and their functions were known in the art (both Boucher in view of Clark’s and Terwilliger’s arrangements were known for providing air to an auxiliary compressor/fan), and c) one of ordinary skill in the art could have substituted one known element for another and the results of the substitution would have been predictable (either Boucher in view of Clark’s arrangement providing air from the environment external to the aircraft via an unspecified pathway to a compressor or Terwilliger’s arrangement providing RAM air to a fan could have been used to predictably provide air for an auxiliary compressor/fan to perform work on, as evidenced by Terwilliger’s teaching of various sources of air for such a compressor/fan including from bypass air, RAM air, or air from another engine or aircraft system). It has been held that “when a patent claims a structure already known in the prior art that is altered by the mere substitution of one element for another known in the field, the combination must do more than yield a predictable result.” KSR International Co. v. Teleflex Inc., et al., 82 USPQ2d 1385, 1395 (2007) (citing United States v. Adams, 383 US 39, 50-51 (1966)). See MPEP 2143 I(B). The proposed modification of Boucher in view of Clark with Terwilliger results in the air circuit inlet and the engine inlet each being independently fluidly coupled to the environment external to the aircraft.
Regarding Dependent Claim 17, Boucher in view of Clark further in view of Terwilliger teaches the invention as claimed and as discussed above for claim 16, and Clark further teaches the pneumatic system comprises a pneumatic anti-icing system (anti-ice systems; para. [0073]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Boucher in view of Clark further in view of Terwilliger’s system such that the pneumatic system comprises a pneumatic anti-icing system, as taught by Clark, for the reasons cited above for claim 16 and to provide the anti-icing system (Clark; para. [0073]).
Regarding Dependent Claim 19, Boucher in view of Clark further in view of Terwilliger teaches the invention as claimed and as discussed above for claim 16, and Clark further teaches the pneumatic system comprises an environmental control system for the aircraft (for supply of cabin air; para. [0073]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Boucher in view of Clark further in view of Terwilliger’s system such that the pneumatic system comprises an environmental control system for the aircraft, as taught by Clark, for the reasons cited above for claim 16 and to provide cabin air (Clark; para. [0073]).
Claim 18 is rejected under 35 U.S.C. 103 as being unpatentable over Boucher in view of Clark further in view of Terwilliger, as applied to claim 16 above, and further in view of Palmer 20240133343.
Regarding Dependent Claim 18, Boucher in view of Clark further in view of Terwilliger teaches the invention as claimed and as discussed above for claim 16, and Clark further teaches the pneumatic system can be “for anti-ice systems or for cabin air, etc.,” thus indicating that the pneumatic system may include other systems that can make use of compressed air from the air compressor (para. [0073]).
Boucher in view of Clark further in view of Terwilliger fails to expressly teach the pneumatic system comprises a pneumatic actuator.
Palmer teaches a system with an air compressor driven by a turboexpander (Fig. 4, compressor 450 driven by turboexpander 340), the compressor supplying air for a variety of purposes, such as to a pneumatic system comprising a pneumatic actuator (para. [0071]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Boucher in view of Clark further in view of Terwilliger’s system such that the pneumatic system comprises a pneumatic actuator, as taught by Palmer, given Clark’s and Palmer’s suggestions of using compressed air from the air compressor for a variety of purposes (Clark, para. [0073]; Palmer, para. [0071]) and because Palmer suggests the use of such compressed air to power actuators (Palmer; para. [0071]).
Response to Arguments
Applicant's arguments filed 11/25/2025 have been fully considered and are moot in part and unpersuasive in part.
Applicant’s arguments (pp. 6-10 & 16-18 of Remarks) with respect to the rejections relying on Boucher, that Boucher fails to teach a compressor because Boucher’s “fan” is not a “compressor,” are unpersuasive (see the relevant rejections above explaining that fans inherently pressurize air and that given the location of the fan in Boucher, coupled with a turbofan engine but not for propulsion, and the fact that the fan is driven by a turbine which would provide a substantial amount of power, the fan would be understood by one of ordinary skill in the art to be a “compressor” as claimed).
Applicant’s arguments (pp. 6-10 of Remarks) with respect to the rejections over Boucher that Boucher fails to teach the engine inlet and the air circuit/air compressor inlet are each separately or independently coupled to the environment external to the aircraft are moot in view of the new grounds of rejection under 35 U.S.C. 103 which rely on Terwilliger for this teaching.
Applicant’s arguments (pp. 10-14 & 16-18 of Remarks) with respect to the rejections relying on Clark that Clark fails to teach the engine inlet and the air circuit/air compressor inlet are each separately or independently coupled to the environment external to the aircraft are moot in view of the new grounds of rejection under 35 U.S.C. 103 which rely on Terwilliger for this teaching.
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.
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/SCOTT J WALTHOUR/Primary Examiner, Art Unit 3741