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 .
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
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 1-2 is/are rejected under 35 U.S.C. 103 as being unpatentable over Khaled (US20230358449) in view of Applicant Admitted Prior Art Figure 2 (AAPA) and Hu et al (CN 110957504 A).
In re Claim 1, Khaled discloses a system (Fig. 3) comprising:
a refrigerant (LH2) subcooling system including:
a primary flowline ([0053]: flowline designated first side into 216);
a secondary flowline (207) fluidly coupled to the primary flowline (coupled via 205);
an expansion valve (EEV) coupled to the secondary flowline (207),
the expansion valve (EEV) to reduce a saturated pressure and a temperature of refrigerant in the secondary flowline1; and
a heat exchanger (206) fluidly coupled to the primary flowline (via 216) and the secondary flowline (207 becomes 218),
the heat exchanger (206) to transfer heat from the refrigerant in the primary flowline to the refrigerant in the secondary flowline ([0053]: flow through second side 218 of 206 and may absorb heat from the first side 216).
However, Khaled does not explicitly teach, using liquid hydrogen and a superconducting (SC) motor to power a propulsor of an aircraft; a primary flowline fluidly coupled to a cooling assembly of the SC motor; and a fuel cell stack coupled to the primary flowline and the cooling assembly.
On the other hand, AAPA teaches using liquid hydrogen and a motor (AAPA 206) to power a propulsor (AAPA 223) of an aircraft ([0040]: propulsor is for an aircraft); fluidly coupled to a cooling assembly (208) of the motor (206); and a fuel cell stack (210) coupled to the primary flowline (flow line leaving fuel distribution system 202) and the cooling assembly (208).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention, to have taken the teachings of Khaled and to have modified them by
substituting the liquid refrigerant of Khaled with liquid hydrogen since it has been shown that a simple substitution of one known element for another to yield predictable results is obvious. The two liquids perform the same function and as such can be viewed as obvious in view of one another (See AAPA [0040]); and
having a motor to power a propulsor of an aircraft; a primary flowline fluidly coupled to a cooling assembly of the motor; and a fuel cell stack coupled to the primary flowline and the cooling assembly, in order to generate thrust for the aircraft. (See AAPA [0042]), without yielding unpredictable results.
However, Khaled as modified AAPA does not explicitly teach a superconducting motor.
On the other hand, Hu teaches a motor that is a superconducting motor (40)|(See Page 6¶6).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention, to have taken the teachings of Khaled/AAPA and to have modified them by having the motor be a superconducting motor, in order to improve the working efficiency of the system with a motor that has resistive heating, i.e., by using a superconducting motor no electrical energy is lost inside the windings of the motor (See Hu Page 6¶6), without yielding unpredictable results.
In re Claim 2, Khaled as modified teaches a controller (232)
Furthermore, the recitation of " to: cause the LH2 subcooling system to reduce a first temperature of the LH2 in the primary flowline when the first temperature does not satisfy a subcooling threshold; and cause the LH2 subcooling system to increase a flowrate of the LH2 in the primary flowline when a second temperature of the SC motor does not satisfy a superconducting threshold," recited in the claim has been considered a recitation of intended use. The prior art structure above is capable of performing as intended. It has been held that the recitation with respect to the manner in which a claimed apparatus is intended to be employed does not differentiate the claimed apparatus from a prior art apparatus satisfying the claimed structural limitation. (MPEP 2114).
Claim 3 is/are rejected under 35 U.S.C. 103 as being unpatentable over Khaled (US20230358449A1) as modified by Applicant Admitted Prior Art Figure 2 (AAPA) and Hu et al (CN 110957504 A) further in view of Kim et al (US20220364505A1), hereinafter Khaled, AAPA and Kim.
In re Claim 3, Khaled/AAPA is silent on wherein the system is a first system fluidly coupled to a second system same as the first system.
However, Kim (Fig. 8) teaches wherein the system (880 left wing) is a first system fluidly coupled to a second system (880 right wing) same as the first system (880 left wing).
Therefore, it would have been obvious to one having ordinary skill in the art at the time the invention was made to have taken the teachings of Khaled/AAPA and to have modified them by having a first system fluidly coupled to a second system same as the first system, since it has been held that mere duplication of essential working parts of a device involve only routine skill in the art.
Allowable Subject Matter
Claims 4-5, 8-16 and 18 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. The prior art, when taken as a whole, neither anticipates nor render prima facie obvious the claimed invention as currently recited in at least claims 4-5 and 8.
Reasons for Allowance
The following is an examiner’s statement of reasons for allowance: Applicant has not amended the claims by incorporating the previously-indicated allowable subject matter from claims 4-5 and 8 into independent claim 1. Applicant has corrected the previous claim objections. The detailed Reasons for Allowance, made of record in pages 8-11 of the Non-Final Office action mailed on October 1, 2025, are hereby incorporated by reference in their entirety.
Response to Arguments
Applicant’s December 30, 2025 arguments, on Pages 8-9 of the Remarks, with respect to the rejection of claims 1-3 under 35 U.S.C. § 103 have been fully considered and are persuasive. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground(s) of rejection is made in view of Khaled ( US20230358449A1).
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to IBRAHIM M ADENIJI whose telephone number is (571)272-5939. The examiner can normally be reached 8:00-5:00 PM.
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/IBRAHIM A. MICHAEL ADENIJI/Examiner, Art Unit 3763
/JIANYING C ATKISSON/Supervisory Patent Examiner, Art Unit 3763
1 The recitation of " to reduce a saturated pressure and a temperature of LH2 in the secondary flowline," recited in the claim has been considered a recitation of intended use. The prior art structure above is capable of performing as intended. It has been held that the recitation with respect to the manner in which a claimed apparatus is intended to be employed does not differentiate the claimed apparatus from a prior art apparatus satisfying the claimed structural limitation. (MPEP 2114).