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 .
Status of Claims
Applicant’s amendment and arguments, filed 01/16/26, have been fully considered. Claim(s) 1, 13, and 19 is/are amended; claim(s) 2–12 and 14–17 stand(s) as originally or previously presented; claims 18 and 20 are canceled; and claims 21 and 22 are added without entering new matter. Examiner affirms that the original disclosure provides adequate support for the amendment.
Upon considering said amendment and arguments, the previous 35 U.S.C. 103 rejection set forth in the Office Action mailed 10/16/2025 has/have been withdrawn. Applicant’s amendment necessitated the new grounds of rejection below.
Claim Objections
Claim 19 is objected to for the following informality: in lines 2 and 3, “the front portion of the fuel cell system is located at the center of the main wings and between the plurality of batteries” should read “the front portion of the fuel cell system is further located at the center of the main wings and between the plurality of batteries” to clarify that such is in addition to parent claim 13’s “front portion of the fuel cell system … located forward of a rear end of the main wings”, as is clear from fig. 1. Appropriate correction is required.
Claim Rejections - 35 USC § 103
The text forming the basis for the rejection under 35 U.S.C. 103 may be found in a prior Office Action.
Claim(s) 1 and 7–11 is/are rejected under 35 U.S.C. 103 as being unpatentable over Riediger et al. (WO 2022073543 A1; citation to English equivalent US 20230348081 A1) (Riediger) in view of Medici et al. (WO 2023223119 A1) (Medici) and Igarashi et al. (JP 2006099988 A) (Igarashi).
Regarding claims 1 and 9, Riediger discloses an aircraft (fig. 1A/B) comprising: a fuselage (22).
Riediger further discloses a “second” horizontal stabilizer (21) located at a rear end of the fuselage (per fig.) but fails to explicitly disclose a first horizontal stabilizer located at a front end of the fuselage.
Medici teaches an aircraft (Title) with front and rear horizontal stabilizers (aerodynamic surfaces 9 and 8, respectively, fig. 9), where the front stabilizers ensure the desired degree of longitudinal stability to the aircraft (p. 9, lines 29–34).
Medici and Riediger are analogous prior art to the claimed invention because they pertain to the same field of endeavor, namely aircraft.
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to install front horizontal stabilizers on Riediger’s aircraft, as taught by Medici, with the reasonable expectation of ensuring the desired degree of longitudinal stability to the aircraft, as taught by Medici.
Riediger further discloses (per annot. fig. 1A below) main wings (26) located to extend from opposite sides of the fuselage at a position between the front end and the rear end of the fuselage (per fig.); a fuel cell system (FCS) configured to generate electrical energy and supply the electrical energy to an electrical motor configured to drive a propeller of the aircraft (¶ 0087, 0088); and a controller (90, denoted as hybrid propulsion controller) configured to cause transmission of the electrical energy to the electrical motor (e.g., ¶ 0092).
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Riediger further discloses that the controller monitors/controls parameters such as fuel supply, speeds of the power and high-pressure shaft, and temperature of gas turbines 41 and 42 (¶ 0092), though Riediger fails to explicitly disclose that the controller is configured to control a flow rate of air into the fuel cell system in response to a determined outside air condition of air outside the aircraft.
Igarashi, in teaching a fuel-cell system (Title), teaches a controller (¶ 0015 and ref, 49 of FIG. 2) configured to control a flow rate of air into the system in response to a determined outside air condition of outside air (per ¶ 0015 and 0016, the controller controls the compressor’s rotation speed depending on the detected outside air temperature and pressure to meet the target air flow rate). Igarashi teaches that this system allows the manipulated variable of the pressure-control means to always be able to be calculated and corrected even if atmospheric pressure around the system changes (¶ 0007), which is critical for maintaining pressure and efficient power generation yet is difficult to control using conventional fuel cells (¶ 0003, 0004).
Igarashi is analogous prior art to the claimed invention because they pertain to the same field of endeavor, namely fuel cells and controllers.
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to configure Riediger’s controller to control air-flow rate in response to a determined outside air condition such as temperature, as taught by Igarashi, with the reasonable expectation of maintaining efficient power generation by always allowing the pressure-control variable to be calculated and corrected even during atmospheric-pressure changes, as taught by Igarashi.
Riediger further discloses that a front portion of the fuel cell system is located forward of a rear end of the main wings (per above fig.), and a center of gravity of the aircraft is located at a location in the fuselage that is in line with front ends of the main wings (see plane’s center of gravity SP appearing directly below motor-generator unit 71 in fig. 1B, which, if viewed in terms of fig. 1A, aligns with the front ends of the main wings; compare to substantially similar instant fig. 1).
As seen in figs. 1A/B and discussed above, Riediger discloses an aircraft center of gravity (COG) aligned with the plane’s wings, where the plane’s COG is based on the components and their corresponding weights in the front and rear of the fuselage (fig. 1B) so that a moment equilibrium forms that is essentially neutral to the plane’s COG (¶ 0090), where the skilled artisan would reasonably understand components such as hydrogen tank 74—in the fuselage’s rear, behind the main wings (fig. 1A)—in being known to be some of the fuel cell system’s most massive components (see, e.g., Riediger’s ¶ 0046 and 0059), to exhibit the heaviest weights and, thus, reasonably dictate the system’s COG.
Though Riediger fails to explicitly disclose that a center of gravity of the fuel cell system is located rear to the main wings, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to configure Riediger’s fuel cell system’s COG to be rear to the main wings—e.g., via positioning of the components such as the hydrogen tank—with the reasonable expectation of maintaining Riediger’s desired balance via the moment equilibrium. Moreover, such modification would appear to only require routine component positioning, which is generally prima facie obvious because such requires only routine skill, absent modification to the device’s operation (MPEP 2144.04 (VI.)(C.)), which would not seem to occur because such components would only appear to shift within the aircraft while maintaining their physical and/or electrical connections.
It is submitted that the above disclosure further reads on claim 9; i.e., the determined outside air condition comprises at least a temperature (Igarashi, ¶ 0015 and 0016).
Regarding claim 7, modified Riediger discloses the aircraft of claim 1, wherein at least one driving device is provided on each of the main wings (turbines 41/42 or propellers 61/62 in Riediger’s annot. fig. 1A).
Regarding claim 8, modified Riediger discloses the aircraft of claim 1, further comprising an auxiliary EPU (transmission 80 plus converters 81/82, Riediger’s annot. fig. 1A and fig. 3) configured to transmit the electrical energy generated by the fuel cell system to the electrical motor (Riediger, ¶ 0088).
Regarding claims 10 and 11, modified Riediger discloses the aircraft of claim 1, wherein the controller is configured to determine, based on the determined outside air condition, a rate of rotation of a blower adjacent to an inlet portion of the fuel cell system (note compressor 21 (which, per Igarashi, ¶ 0015, rotates and supplies the air introduced from the inlet and, thus, comprises a fan/blower) adjacent inlet in Igarashi’s annotated fig. 2 below; per Igarashi, ¶ 0015 and 0016, the controller detects the compressor’s rotation speed in response to the outside air temperature), wherein
the determined outside air condition comprises a temperature (Igarashi, ¶ 0015 and 0016); and wherein the controller is configured to control the rate of rotation of the blower by: based on a decrease in the temperature, decreasing the rate of rotation to decrease a flow rate of air flowing into the fuel cell system (lowering compressor rotation speed in response to lower outside air temperature, Igarashi, ¶ 0031); or based on an increase in the temperature, increasing the rate of rotation to increase a flow rate of air flowing into the fuel cell system (raising compressor rotation speed in response to higher outside air temperature, Igarashi, ¶ 0031).
Claim(s) 2, 4, 12, and 21 is/are rejected under 35 U.S.C. 103 as being unpatentable over Riediger et al. (WO 2022073543 A1; citation to English equivalent US 20230348081 A1) (Riediger) in view of Medici et al. (WO 2023223119 A1) (Medici) and Igarashi et al. (JP 2006099988 A) (Igarashi), as applied to claim 1, further in view of Maslyn et al. (US 20160087288 A1) (Maslyn).
Regarding claims 2 and 4, modified Riediger discloses the aircraft of claim 1, wherein the fuel cell system comprises a fuel cell stack (it is submitted that Riediger’s fuel cell 73 would necessarily include a “stack” of at least two electrodes (i.e., oxygen and H2/fuel, as implied from Riediger’s hydrogen storage tank 74) separated by some ion-conducting membrane like a PEM because such are integral for a fuel cell to generate ions and electrons/current, as seen in Riediger’s ¶ 0088); and a hydrogen storage tank connected to the fuel cell stack (Riediger’s ref. 74 above connected to fuel cell 73 by fuel line).
However, in being unconcerned with further details of the fuel cell system, Riediger fails to explicitly disclose that the system comprises an inlet portion configured to cause outside air to be introduced into the fuel cell system; a fuel cell stack connected to the inlet portion; an air recirculation loop formed between the inlet portion and a discharge portion of the fuel cell stack, wherein the discharge portion is configured to cause air to be discharged from the fuel cell stack; a blower located adjacent to the inlet portion; and a compressor configured to compress air introduced through the inlet portion.
Igarashi further teaches (per annot. fig. 2 below) that the fuel cell system includes an inlet portion (denoted) configured to cause outside air to be introduced into the fuel cell system (¶ 0013) and connected to the fuel cell stack (fluidically, per below), wherein the discharge portion is configured to cause air to be discharged from the fuel cell stack (per below and ¶ 0013); a blower located adjacent to the inlet portion (compressor 21 (which, per ¶ 0015, rotates and supplies the air introduced from the inlet and, thus, comprises a fan/blower) adjacent inlet below); and a compressor configured to compress air introduced through the inlet portion (compressor 21, per below and ¶ 0013).
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It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to adopt Igarashi’s specific components as Riediger’s general fuel cell system, as with the reasonable expectation of achieving a successful system for generating electricity and achieving Igarashi’s benefits of maintained pressure and power generation, as discussed above and suggested by Igarashi.
However, despite disclosing the air inlet and discharge portions of the fuel cell stack, modified Riediger fails to explicitly disclose an air recirculation loop formed between the inlet and discharge portions.
Maslyn, in teaching a fuel-cell system (Title), teaches a cathode gas recirculation valve 114 and corresponding recirculation line coupled between inlet and discharge portions to receive cathode exhaust gas and selectively provide the exhaust gas to the compressor input (Abstract, fig. 1). Maslyn teaches that recirculating the cathode gas, i.e., air, may improve anion contaminant removal as well as reduce the need to draw load to the cell via voltage-suppression operations or force a large voltage cycle (¶ 0006), which is important for stability and proper current distribution (¶ 0004).
Maslyn is analogous prior art to the claimed invention because they pertain to the same field of endeavor, namely fuel cells.
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to incorporate Maslyn’s air recirculation loop into Igarashi’s system with the reasonable expectation that doing so would improve anion contaminant removal while maintaining the cell’s stability and proper current distribution, as taught by Maslyn.
Regarding claim 12, modified Riediger discloses the aircraft of claim 2.
Modified Riediger further discloses the controller (Riediger’s ref. 90) and the air recirculation loop (per Maslyn) but fails to explicitly disclose that the controller is configured to drive the air recirculation loop when an oxygen concentration measured at the discharge portion satisfies a threshold.
Maslyn, per parent claim 2, teaches cathode gas recirculation valve coupled between inlet and discharge portions to receive cathode exhaust gas and selectively provide the exhaust gas to the compressor input (Abstract, fig. 1). Maslyn teaches that a controller activates the recirculation loop by selectively recirculating cathode exhaust when the cell reaches a threshold output voltage associated with a particular oxygen concentration in the cathode to control the O2 concentration (e.g., ¶ 0010, 0019, ¶ 0034–0036; note also that, per, e.g., ¶ 0007 and fig. 2, Maslyn’s exhaust-gas output, i.e., discharge portion, is fluidically and electrically connected to the cathode and recirculation loop, and, thus, Maslyn’s controller would reasonably be configured to drive the recirculation loop based on O2 measured at the “discharge portion”), which may ensure continued fuel-cell performance over time by improving anion removal in the cathode (¶ 0004, 0006).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to configure Riediger’s controller to perform Maslyn’s recirculation-activation function—specifically such that the controller would be configured to drive recirculation based on O2 measured at Riediger’s discharge portion—with the reasonable expectation of allowing oxygen-concentration control, ensuring continued fuel-cell performance over time by improving anion removal in the cathode, as taught by Maslyn.
Regarding claim 21, modified Riediger discloses the aircraft of claim 2, wherein the hydrogen storage tank is located rear to the fuel cell stack (per Riediger’s annot. fig. 1A, where the FC stack (i.e., electrodes with ion-conducting membrane, as in Igarashi’s stack) is necessarily within the fuel cell).
Claim(s) 3 is/are rejected under 35 U.S.C. 103 as being unpatentable over Riediger et al. (WO 2022073543 A1; citation to English equivalent US 20230348081 A1) (Riediger) in view of Medici et al. (WO 2023223119 A1) (Medici) and Igarashi et al. (JP 2006099988 A) (Igarashi), as applied to claim 1, further in view of Maslyn et al. (US 20160087288 A1) (Maslyn), as applied to claim 2, further in view of Villanueva et al. (US 20210391627 A1) (Villanueva).
Regarding claim 3, modified Riediger discloses the aircraft of claim 2.
Riediger further discloses that an optional energy storage device such as a battery—which would reasonably be high-voltage to help power the plane—may be added to the system to ensure rapid load follow-up and power peak saving to optimize fuel cell system dimensioning (¶ 0088), though Riediger fails to explicitly embody such in the above figs.
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to add at least two high-voltage batteries to Riediger’s aircraft with the reasonable expectation of ensuring rapid load follow-up and power peak saving to optimize fuel cell system dimensioning, as taught by Riediger. Moreover, scaling the number of batteries from one to two to achieve the desired power storage would merely involve duplicating components, which is generally prima facie obvious, absent secondary considerations (MPEP 2144.04 (B.)).
Moreover, Riediger discloses that the controller is configured to control transmission of electrical energy to the electrical motor via the fuel cell system (as discussed in claim 1).
However, in being unconcerned with the batteries’ position in the aircraft, Riediger fails to explicitly disclose that a battery is located on each of the main wings.
Villanueva, in teaching a battery-powered aircraft (Abstract), teaches that the batteries can be arranged in/on the wings (¶ 0043, 0053).
Villanueva is analogous prior art to the claimed invention because they pertain to the same field of endeavor, namely electric aircraft.
It would have been obvious to one of ordinary skill in the art, before the claimed invention's effective filing date, that Riediger’s batteries must necessarily be located somewhere on the aircraft, and, as demonstrated by Villanueva, the skilled artisan would find it obvious to position the battery in/on each wing as an appropriate position.
Claim(s) 5 is/are rejected under 35 U.S.C. 103 as being unpatentable over Riediger et al. (WO 2022073543 A1; citation to English equivalent US 20230348081 A1) (Riediger) in view of Medici et al. (WO 2023223119 A1) (Medici) and Igarashi et al. (JP 2006099988 A) (Igarashi), as applied to claim 1, further in view of Maslyn et al. (US 20160087288 A1) (Maslyn), as applied to claim 2, further in view of Rainville (US 20200388865 A1).
Regarding claim 5, modified Riediger discloses the aircraft of claim 2.
However, in being unconcerned with the position of the inlet, modified Riediger fails to explicitly disclose that the inlet portion is positioned adjacent to an upper side of the fuselage.
Rainville, in teaching an aircraft with a fuel cell (Abstract, ¶ 0016, FIG. 1), teaches air inlet 109 atop fuselage 107 (FIG. 1, ¶ 0016).
Rainville is analogous prior art to the claimed invention because they pertain to the same field of endeavor, namely fuel-cell-powered aircraft.
It would have been obvious to one of ordinary skill in the art, before the claimed invention's effective filing date, that modified Riediger’s inlet portion must necessarily be located somewhere on the aircraft, and, as demonstrated by Rainville, the skilled artisan would find it obvious to arrange the inlet atop the fuselage as an appropriate position.
Claim(s) 6 is/are rejected under 35 U.S.C. 103 as being unpatentable over Riediger et al. (WO 2022073543 A1; citation to English equivalent US 20230348081 A1) (Riediger) in view of Medici et al. (WO 2023223119 A1) (Medici) and Igarashi et al. (JP 2006099988 A) (Igarashi), as applied to claim 1, further in view of Maslyn et al. (US 20160087288 A1) (Maslyn), as applied to claim 4, further in view of Ballantine et al. (US 20210020974 A1) (Ballantine).
Regarding claim 6, modified Riediger discloses the aircraft of claim 4.
Modified Riediger, as part of Igarashi’s fuel cell system, further discloses a radiator 32 for maintaining the fuel cell’s temperature (Igarashi’s fig. 2) though appears to fail to disclose a distinct heat exchanger configured to heat at least a portion of air introduced through the inlet portion.
Ballantine teaches a substantially similar fuel cell system including a heat exchanger 336 to heat input cathode air (fig. 3, ¶ 0036).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to routinely incorporate Ballantine’s heat exchanger into modified Riediger’s fuel cell system and configure such to heat the input cathode air, as taught by Ballantine, with the reasonable expectation of predictably heating the air to the desired temperature before further input into the cathode, as suggested by Ballantine (see also MPEP 2143 (A.)).
Claim(s) 13–17 and 22 is/are rejected under 35 U.S.C. 103 as being unpatentable over Riediger et al. (WO 2022073543 A1; citation to English equivalent US 20230348081 A1) (Riediger) in view of Medici et al. (WO 2023223119 A1) (Medici), Igarashi et al. (JP 2006099988 A) (Igarashi), and Maslyn et al. (US 20160087288 A1) (Maslyn).
Regarding claims 13–15 and 22, Riediger discloses an aircraft (fig. 1A/B) comprising: a fuselage (22).
Riediger further discloses a “second” horizontal stabilizer (21) located at a rear end of the fuselage (per fig.) but fails to explicitly disclose a a first horizontal stabilizer located at a front end of the fuselage.
Medici teaches an aircraft (Title) with front and rear horizontal stabilizers (aerodynamic surfaces 9 and 8, respectively, fig. 9), where the front stabilizers ensure the desired degree of longitudinal stability to the aircraft (p. 9, lines 29–34).
Medici and Riediger are analogous prior art to the claimed invention because they pertain to the same field of endeavor, namely aircraft.
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to install front horizontal stabilizers on Riediger’s aircraft, as taught by Medici, with the reasonable expectation of ensuring the desired degree of longitudinal stability to the aircraft, as taught by Medici.
Riediger further discloses (per annot. fig. 1A below) main wings (26) located to extend from opposite sides of the fuselage at a position between the front end and the rear end of the fuselage (per fig.); a fuel cell system (FCS) configured to generate electrical energy and supply the electrical energy to an electrical motor configured to drive a propeller of the aircraft (¶ 0087, 0088); and a controller (90, denoted as hybrid propulsion controller) configured to cause transmission of the electrical energy to the electrical motor (e.g., ¶ 0092).
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Riediger further discloses that the controller monitors/controls parameters such as fuel supply, speeds of the power and high-pressure shaft, and temperature of gas turbines 41 and 42 (¶ 0092), though Riediger fails to explicitly disclose that the controller is configured to control a flow rate of air into the fuel cell system in response to a determined outside air condition of air outside the aircraft.
Igarashi, in teaching a fuel-cell system (Title), teaches a controller (¶ 0015 and ref, 49 of FIG. 2) configured to control a flow rate of air into the system in response to a determined outside air condition of outside air (per ¶ 0015 and 0016, the controller controls the compressor’s rotation speed depending on the detected outside air temperature and pressure to meet the target air flow rate). Igarashi teaches that this system allows the manipulated variable of the pressure-control means to always be able to be calculated and corrected even if atmospheric pressure around the system changes (¶ 0007), which is critical for maintaining pressure and efficient power generation yet is difficult to control using conventional fuel cells (¶ 0003, 0004).
Igarashi is analogous prior art to the claimed invention because they pertain to the same field of endeavor, namely fuel cells and controllers.
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to configure Riediger’s controller to control air-flow rate in response to a determined outside air condition such as temperature, as taught by Igarashi, with the reasonable expectation of maintaining efficient power generation by always allowing the pressure-control variable to be calculated and corrected even during atmospheric-pressure changes, as taught by Igarashi.
Riediger further discloses that a front portion of the fuel cell system is located forward of a rear end of the main wings (per above fig.), and a center of gravity of the aircraft is located at a location in the fuselage that is in line with front ends of the main wings (see plane’s center of gravity SP appearing directly below motor-generator unit 71 in fig. 1B, which, if viewed in terms of fig. 1A, aligns with the front ends of the main wings; compare to substantially similar instant fig. 1).
As seen in figs. 1A/B and discussed above, Riediger discloses an aircraft center of gravity (COG) aligned with the plane’s wings, where the plane’s COG is based on the components and their corresponding weights in the front and rear of the fuselage (fig. 1B) so that a moment equilibrium forms that is essentially neutral to the plane’s COG (¶ 0090), where the skilled artisan would reasonably understand components such as hydrogen tank 74—in the fuselage’s rear, behind the main wings (fig. 1A)—in being known to be some of the fuel cell system’s most massive components (see, e.g., Riediger’s ¶ 0046 and 0059), to exhibit the heaviest weights and, thus, reasonably dictate the system’s COG.
Though Riediger fails to explicitly disclose that a center of gravity of the fuel cell system is located rear to the main wings, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to configure Riediger’s fuel cell system’s COG to be rear to the main wings—e.g., via positioning of the components such as the hydrogen tank—with the reasonable expectation of maintaining Riediger’s desired balance via the moment equilibrium. Moreover, such modification would appear to only require routine component positioning, which is generally prima facie obvious because such requires only routine skill, absent modification to the device’s operation (MPEP 2144.04 (VI.)(C.)), which would not seem to occur because such components would only appear to shift within the aircraft while maintaining their physical and/or electrical connections.
Riediger further discloses that the fuel cell system comprises a fuel cell stack (it is submitted that Riediger’s fuel cell 73 would necessarily include a “stack” of at least two electrodes (i.e., oxygen and H2/fuel, as implied from Riediger’s hydrogen storage tank 74) separated by some ion-conducting membrane like a PEM because such are integral for a fuel cell to generate ions and electrons/current, as seen in Riediger’s ¶ 0088); and a hydrogen storage tank connected to the fuel cell stack (Riediger’s ref. 74 above connected to fuel cell 73 by fuel line).
However, in being unconcerned with further details of the fuel cell system, Riediger fails to explicitly disclose that the system comprises an inlet portion configured to cause outside air to be introduced into the fuel cell system; a fuel cell stack connected to the inlet portion; an air recirculation loop formed between the inlet portion and a discharge portion of the fuel cell stack, wherein the discharge portion is configured to cause air to be discharged from the fuel cell stack; a blower located adjacent to the inlet portion; and a compressor configured to compress air introduced through the inlet portion.
Igarashi further teaches (per annot. fig. 2 below) that the fuel cell system includes an inlet portion (denoted) configured to cause outside air to be introduced into the fuel cell system (¶ 0013) and connected to the fuel cell stack (fluidically, per below), wherein the discharge portion is configured to cause air to be discharged from the fuel cell stack (per below and ¶ 0013); a blower located adjacent to the inlet portion (compressor 21 (which, per ¶ 0015, rotates and supplies the air introduced from the inlet and, thus, comprises a fan/blower) adjacent inlet below); and a compressor (claim 14) configured to compress air introduced through the inlet portion (compressor 21, per below and ¶ 0013).
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It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to adopt Igarashi’s specific components as Riediger’s general fuel cell system with the reasonable expectation of achieving a successful system for generating electricity and achieving Igarashi’s benefits of maintained pressure and power generation, as discussed above and suggested by Igarashi.
However, despite disclosing the air inlet and discharge portions of the fuel cell stack, modified Riediger fails to explicitly disclose an air recirculation loop formed between the inlet and discharge portions.
Maslyn, in teaching a fuel-cell system (Title), teaches a cathode gas recirculation valve 114 and corresponding recirculation line coupled between inlet and discharge portions to receive cathode exhaust gas and selectively provide the exhaust gas to the compressor input (Abstract, fig. 1). Maslyn teaches that recirculating the cathode gas, i.e., air, may improve anion contaminant removal as well as reduce the need to draw load to the cell via voltage-suppression operations or force a large voltage cycle (¶ 0006), which is important for stability and proper current distribution (¶ 0004).
Maslyn is analogous prior art to the claimed invention because they pertain to the same field of endeavor, namely fuel cells.
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to incorporate Maslyn’s air recirculation loop into Igarashi’s system with the reasonable expectation that doing so would improve anion contaminant removal while maintaining the cell’s stability and proper current distribution, as taught by Maslyn.
It is submitted that the above disclosure further reads on the following:
(claim 15) the determined outside air condition comprises at least a temperature (Igarashi, ¶ 0015 and 0016);
(claim 22) the hydrogen storage tank is located rear to the fuel cell stack (per Riediger’s annot. fig. 1A).
Regarding claims 16 and 17, modified Riediger discloses the aircraft of claim 1, wherein the controller is configured to determine, based on the determined outside air condition, a rate of rotation of a blower adjacent to an inlet portion of the fuel cell system (note compressor 21 (which, per Igarashi, ¶ 0015, rotates and supplies the air introduced from the inlet and, thus, comprises a fan/blower) adjacent inlet in Igarashi’s annotated fig. 2 below; per Igarashi, ¶ 0015 and 0016, the controller detects the compressor’s rotation speed in response to the outside air temperature), wherein
the determined outside air condition comprises a temperature (Igarashi, ¶ 0015 and 0016); and wherein the controller is configured to control the rate of rotation of the blower by: based on a decrease in the temperature, decreasing the rate of rotation to decrease a flow rate of air flowing into the fuel cell system (lowering compressor rotation speed in response to lower outside air temperature, Igarashi, ¶ 0031); or based on an increase in the temperature, increasing the rate of rotation to increase a flow rate of air flowing into the fuel cell system (raising compressor rotation speed in response to higher outside air temperature, Igarashi, ¶ 0031).
Allowable Subject Matter
Claim(s) 19 is/are objected to as being dependent upon a rejected base claim but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims (and rewritten to overcome pending claim objection).
The following is an examiner’s statement of reasons for indicating allowable subject matter:
The present invention relates to, inter alia, an aircraft comprising a fuel cell system and a controlled configured to control a flow rate of air into the fuel cell system in response to a determined outside air condition, wherein a center of gravity of the fuel cell system is rear to the main wings and a front portion of the fuel cell system is forward of a rear end of the main wings, wherein a center of gravity of the aircraft is located at a location in the fuselage that is in line with front ends of the main wings, wherein
(claim 19) the aircraft further comprises a plurality of batteries located on each of the main wings, wherein the front portion of the fuel cell system is located at the center of the main wings and between the plurality of batteries such that the center of gravity of the aircraft is located at the location in the fuselage that is in line with the front ends of the main wings.
Riediger et al. (WO 2022073543 A1; citation to English equivalent US 20230348081 A1) (Riediger) in view of Medici et al. (WO 2023223119 A1) (Medici), Igarashi et al. (JP 2006099988 A) (Igarashi), and Maslyn et al. (US 20160087288 A1) (Maslyn), in disclosing most of the limitations as set forth above, is considered the closest prior art to claim 19.
However, modified Riediger fails to disclose or suggest that the front portion of the fuel cell system is located at the center of the main wings and between the plurality of batteries such that the center of gravity of the aircraft is located at the location in the fuselage that is in line with the front ends of the main wings. To the contrary, although Riediger allows an optional energy storage device such as a battery (¶ 0088), Riediger explicitly discloses that fuel cell 73—which defines the front end of the fuel cell system, as seen in Riediger’s annot. fig. 1A—alongside controller 90 and the electric distribution are positioned in front of the main wings to balance hydrogen tank 74 and form a moment equilibrium essentially neutral with respect to the aircraft’s center of gravity SP (¶ 0090, figs. 1A and 1B)—i.e., essentially opposite to the claimed configuration. As one skilled in the art would recognize that a moment equilibrium entails balanced/stabilized forces within the aircraft, there appears to be no reason for the skilled artisan to abandon Riediger’s balanced components and arbitrarily relocate the front of the fuel cell system to the center of the main wings and between the plurality of batteries such that the aircraft’s center of gravity aligns with the main wings’ front ends.
Medici, Igarashi, and Maslyn were only used to teach specific limitations of the aircraft or fuel cell system and, thus, fail to remedy the above deficiency.
Halsey et al. (US 20180134401 A1) (Halsey), in also disclosing some of the above limitations (see O.A. dated 10/16/25), is prior art also relevant to claim 19. Specifically, Halsey discloses an aircraft with a fuel cell system in the back of the fuselage (power source 20/solid oxide fuel cell multi-power unit (SOFC-MPU) 22, figs. 1 and 2).
However, Halsey fails to disclose or suggest at least that the front portion of the fuel cell system is at the center of the main wings and between the plurality of batteries. To the contrary, even if it were obvious to incorporate batteries onto Halsey’s wings, Halsey fails to recognize the aircraft’s center of gravity, the fuel cell system’s center of gravity, or any other parameter that might motivate the skilled artisan to reposition the fuel cell system’s front end from far behind the wings, much less to align the system at the center of the wings and between the batteries. Thus, there appears to be no reason for the skilled artisan to pursue or expect to necessarily achieve such.
In contrast, Applicant positions the fuel cell system in the recited location as part of configuring the aircraft’s center of gravity to align with the wings’ front ends to provide longitudinal stability and prevent aerodynamic characteristics from deteriorating (¶ 0095–0097). The cited prior art, taken collectively, could not have fairly predicted such improvements from the recited configuration.
Any comments considered necessary by applicant must be submitted no later than the payment of the issue fee and, to avoid processing delays, should preferably accompany the issue fee. Such submissions should be clearly labeled “Comments on Statement of Reasons for Allowance.”
Response to Arguments
Applicant’s arguments with respect to claim(s) 1 and 13 have been considered. Applicant’s amendment overcame the previous 35 U.S.C. 103 rejection—which, as noted above, has been withdrawn—and necessitated the new grounds of rejection newly citing Riediger, as established above.
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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/J.S.M./Examiner, Art Unit 1751
/JONATHAN G LEONG/Supervisory Patent Examiner, Art Unit 1751 2/13/2026