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 .
This is in response to the correspondence received on 6/12/2026.
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 10/14/2025 was entered.
Claim Rejections - 35 USC § 112
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
Claims 1, 15 and their dependent claims, are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention.
Claim 1: the limitation “an alternating-current motor whose sole power input is electrical energy delivered through a second AC power supply circuit” does not appear to be supported by the Specification because it appears to contradict the concept of windmilling described in [0088] (i.e., the recovery of mechanical energy when windmilling indicates that the rotation of the propeller when interacting with air is a “power input” into the alternating-current motor.
Claim 15: in “the electronic control unit is programmed to, during a flight of the aircraft having at least a taxi phase, a take-off phase, a cruising phase, a descent phase, and a landing phase:” does not appear to be supported by the Specification, the closest mention in the specification appears to be “the control unit being programmed to, during a flight of the aircraft comprising, inter alia, a take- off phase, a cruising phase and a landing phase” in [0022].
Claim 15: in “during the taxi phase, electrically power the alternating-current motor of the lift-increase propulsion unit from the one or more electric batteries through the DC/AC converter, while the turboprop is off”, the specification does not appear to support the limitation.
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 (i.e., changing from AIA to pre-AIA ) 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.
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.
Claim(s) 1-4, 9-13 is/are rejected under 35 U.S.C. 103 as being unpatentable over Moxon 20150144742 (Moxon’742) in view of Moxon 20160355272 (Moxon’272) and Himmelmann 20180265206 and Swann 11260983
Regarding claim 1, Moxon’742 teaches:
A propulsion system (“a propulsion system”, Abstract) for a non-rotary-wing aircraft (Title, Abstract) comprising:
an alternating-current generator (electrical power generator (56), Abstact),
at least one lift-increase propulsion unit (inter alia, 46; “the propulsors 46 substantially increase the amount of lift generated by the wings 44” [0036]), comprising one or more propellers (50), and
an alternating-current motor whose sole power input is electrical energy ( “Each propulsor 46 comprises an electric motor (not shown) housed within a nacelle 48“ [0035];]) delivered through a second AC power supply circuit (“Main electrical bus 68” [0041]), the alternating-current motor of the lift-increase propulsion unit being a physical device distinct from the alternating-current generator (“Each electrical generator 56 is connected to a plurality of propulsors 46 on the respective wing by a main electrical bus 68” [0041]), wherein the one or more propellers are mechanically coupled to said alternating-current motor (Fig. 4) and are configured to operate selectively in either (i) a powered operation in which the one or more propellers are driven in rotation by the alternating-current motor (“Each propulsor 46 comprises an electric motor (not shown) housed within a nacelle 48, and a propeller 50 driven by the motor,” [0035]) and (ii) a non-powered operation in which said one or more propellers are rotated by incident airflow and back-drive the alternating-current motor as a generator to recover mechanical energy as electrical energy (aircraft propellers are known to inherently rotate by incidental airflow when not being powered by an engine/motor, unless additional steps are taken to prevent it – i.e., such as placing the propellers in a “feathered” position to avoid windmilling; electric motors are also known in the art to be capable of operating as generators when mechanical power is provided to the rotor, and producing electrical current/energy)
[[a]] the second AC power supply circuit, that electrically connects the generator to the lift-increase propulsion unit (as discussed above, [0041]),
Moxon’742 is silent about:
at least one wingtip propulsion unit comprising an alternating-current motor, having a direction of rotation that opposes formation of wingtip vortices,
a first AC power supply circuit, that electrically connects the alternating- current generator to the at least one wingtip propulsion unit,
However, Moxon’272 teaches an aircraft propulsion system (title), and:
at least one wingtip propulsion unit comprising an alternating-current motor (“Each propulsor 134 is driven by an electric motor 138, which is provided with electrical power from the motor generators 116 “, [0043]), having a direction of rotation that opposes formation of wingtip vortices (“By rotating the propellers in a clockwise direction as viewed from downstream of the propulsor 134 on the port wing 34, and in an opposite direction on the starboard wing, the wingtip vortex can be at least partly cancelled, thereby reducing the wake vortex.” Moxon [0043),
a first AC power supply circuit (inter alia, electrical interconnector 140 [0043]), that electrically connects the alternating-current generator (in the case of Moxon’272, the generator are represented by 116,however, as discussed above, the generators in the combination are already taught by the base reference Moxon’742; Moxon’272 is used here to teach the first AC power supply) to the at least one wingtip propulsion unit (Fig. 3),
It would have been obvious to a person having ordinary skills in the art before the effective filing date of the claimed invention to provide Moxon’742 with Moxon’272's structure discussed above, so “the tip propulsors 134 are located at a point where a wingtip vortex would normally be generated” because “rotating the propellers in a clockwise direction as viewed from downstream of the propulsor 134 on the port wing 34, and in an opposite direction on the starboard wing, the wingtip vortex can be at least partly cancelled, thereby reducing the wake vortex” [0043].
Moxon’742 in view of Moxon’272' is silent about:
wherein the second AC power supply circuit comprises:
an intermediate DC distribution stage,
o one or more electric batteries connected to said intermediate DC distribution stage,
o an AC/DC converter, that electrically connects the generator to said intermediate DC distribution stage, and
o a DC/AC converter, that electrically connects said intermediate stage to the lift-increase propulsion unit,
wherein the first AC power supply circuit is configured to deliver an AC current produced by the generator, to the wingtip propulsion unit, without intermediate conversion of this alternating current into direct current, and wherein the intermediate DC distribution stage is electrically connected in series between the DC/AC converter and the AC/DC converter, and the DC/AC converter constitutes the sole electrical input to each alternating- current motor driving the one or more propellers of the lift-increase propulsion unit.
However, Himmelmann teaches an AC system for an aircraft (Title, abstract), the system with an AC direct power connection (114) and a second circuit, a DC bus 115 which permits the inclusion of an energy storage device ([0017]) and:
AC power supply circuit comprises:
an intermediate DC distribution stage (115),
o one or more electric batteries (112) connected to said intermediate DC distribution stage (Fig 1)
o an AC/DC converter (Bi-directional inverter-rectifiers 108 and 109 are bi-directional rectifiers and inverters insomuch as they can transmit and rectify power in either direction [0014]), that electrically connects the generator (106) to said intermediate DC distribution stage (Fig 1), and
o a DC/AC converter (Bi-directional inverter-rectifiers 108 and 109), that electrically connects said intermediate stage to the lift-increase propulsion unit (Fig 1, where, inter alia, 111 is part of a lift-increase propulsion unit),
and wherein the intermediate DC distribution stage is electrically connected in series between the DC/AC converter and the AC/DC converter (Fig. 1 shows 115 between 109 and 108), and the DC/AC converter constitutes the sole electrical input to each alternating-current motor driving the one or more propellers of the lift-increase propulsion unit (Fig. 1 shows input to 111 as being provided by 109 when power contactor assembly 114 is disconnected [0016], the system is therefore operable with DC/AC converter as the sole electrical input to the motor)
It would have been obvious to a person having ordinary skill the art before the effective filing date of the claimed invention to provide Moxon’742 in view of Moxon’272' with Himmelmann's teachings discussed above in order to have a second power supply circuit to provide electrical power to “an electric propulsion motor is configured to receive the electric power and be selectively driven at an operational speed independent of a rotational speed of the power shaft” as taught by Himmelmann (abstract), and allows for power to be provided by the DC circuit, from the energy storage device, if the gas turbine engine is not operating [0021].
Moxon’742 in view of Moxon’272 and Himmelmann teaches:(ii) configured, during non-powered operation, to rotate in response to airflow so as to back-drive the alternating-current motor to recover mechanical energy as electrical energy, as discussed above since these features are part of these systems. However, to clear any doubt, Swann also teaches the limitations:
Swann teaches an electrically-assisted propulsion control system, with a propulsive fan 220 attached to a motor/generator 224 (Col 10 ll. 59), and:
(ii) configured, during non-powered operation, to rotate in response to airflow so as to back-drive the alternating-current motor to recover mechanical energy as electrical energy (In the descent phase of flight, the engine 210 is in its unlit or idle state. The fan 222 of the propulsive fan 220 (if present) is being driven (“windmilling”) by air-flow resulting from the forward motion of the aircraft, and as a result is causing the generator 224 to generate electrical energy which is used to charge the energy storage unit 200. Additionally or alternatively, the co-located fan 212 of the engine 210 can be used in a “wind-milling” capacity to charge the energy storage unit 200 with electrical energy generated by the generator 214/217” (Col 12, ll. 33-49)).
It would have been obvious to a person having ordinary skills in the art before the effective filing date of the claimed invention to provide Moxon’742 in view of Moxon’272 and Himmelmann with Swann's teachings discussed above because this would advantageously allow aircraft speed to be regulated in support of steeper descents without the need to configure the aerofoils of the aircraft wing into a high-drag high-noise configuration” (Col 12, ll. 33-49).
Regarding claim 2, Moxon’742 in view of Moxon’272, Himmelmann and Swann teaches the invention as discussed for claim 1.
Moxon’742 further teaches:
further comprising a turboprop (“the aircraft (40) comprises a propulsion system comprising a pair of internal combustion engines (10)” abstract, and turboprops [0020], and Fig. 1).
Regarding claim 3, Moxon’742 in view of Moxon’272, Himmelmann and Swann teaches the invention as discussed above.
Moxon’742 in view of Moxon’272, Himmelmann and Swann, as already discussed above teach the first AC power supply circuit and the second AC power supply circuit, but Moxon’742 in view of Moxon’272, Himmelmann and Swann is silent about:
wherein the first AC power supply circuit and the second AC power supply circuit are connected to one another by an AC distribution stage, common to the first and second power supply circuits, the AC distribution stage itself being connected to the generator,
However, Moxon’272 teaches:
An AC power supply circuit (inter alia, 140) and the second AC power supply circuit (as discussed above for claim 1) are connected to one another by an AC distribution stage, common to the first and second power supply circuits (Moxon’272 teaches “propulsor arrangements 100 are electrically interconnected by an interconnector 140” [0041], multiple circuits, i.e., 140 connecting to 134 and 142, that are interconnected to a common distribution stage, inter alia, 140, teaching two AC power supplies, one powering wingtip propulsions unit and the other powering propulsion unit forward of the wing leading edge, see Figs 2 and 3), the AC distribution stage itself being connected to the generator (Fig 3 shows a generator, 116, connected to interconnector 140).
It would have been obvious to a person having ordinary skills in the art before the effective filing date of the claimed invention to provide Moxon’742 in view of Moxon’272, Himmelmann and Swann with Moxon’272's teachings discussed above in order to provide a system wherein the first AC power supply circuit and the second AC power supply circuit are connected to one another by an AC distribution stage, common to the first and second power supply circuits, the AC distribution stage itself being connected to the generator, in order to power the propulsion system with added reliability in case of failure as taught by Moxon’272 [0041] and for the reasons already discussed above.
Moxon’742 in view of Moxon’272, Himmelmann and Swann, as discussed so far, is silent about:
the AC/DC converter of the second AC power supply circuit being connected between the AC distribution stage and the intermediate DC distribution stage,
and wherein the AC/DC converter is reversible, said AC/DC converter allowing both a transfer of electric power from the AC distribution stage to the intermediate DC distribution stage, and from the intermediate DC distribution stage to the AC distribution stage.
However, Himmelmann teaches:
the AC/DC converter (as discussed, Bi-directional inverter-rectifiers 108 and 109) of the second AC power supply circuit (as discussed for claim 1) being connected between the AC distribution stage (113) and the intermediate DC distribution stage (115) (Fig 1),
and wherein the AC/DC converter (Bi-directional inverter-rectifiers 108 and 109) is reversible (Bi-directional inverter-rectifiers 108 and 109 are bi-directional rectifiers and inverters insomuch as they can transmit and rectify power in either direction [0014]), said converter allowing both a transfer of electric power from the AC distribution stage to the intermediate DC distribution stage, and from the intermediate DC distribution stage to the AC distribution stage ([0014] and Fig 1).
Regarding claim 4, Moxon’742 in view of Moxon’272, Himmelmann and Swann teaches the invention as discussed above.
Moxon’742 in view of Moxon’272 Himmelmann and Swann, as discussed so far, is silent about:
the DC/AC converter of the second AC power supply circuit is reversible, said converter allowing both a transfer of electric power from the intermediate DC distribution stage to the lift-increase propulsion unit, and from the lift-increase propulsion unit to the intermediate DC distribution stage.
However, Himmelmann teaches:
Propulsion system (inter alia, 111) according to any preceding claim, wherein the DC/AC converter of the second power supply circuit is reversible (Bi- bi-directional inverter-rectifier 108 and 109 are directional rectifiers and inverters in so much as they can transmit and rectify power in either direction [0014]), said converter allowing both a transfer of electric power from the intermediate DC distribution stage to the lift-increase propulsion unit, and from the lift-increase propulsion unit (as discussed above for claim 1) to the intermediate DC distribution stage (they can transmit and rectify power in either direction [0014]).
Regarding claim 9, Moxon’742 in view of Moxon’272, Himmelmann and Swann teaches the invention as discussed for claim 1.
Moxon’742 further teaches:
A non-rotary-wing aircraft (Figs. 1, 2, 4) comprising:
a fuselage, a left wing that extends to the left of the fuselage and a right wing that extends to the right of the fuselage (Figs. 1, 2, 4),
a first propulsion system (port side of the aircraft) and a second propulsion system (starboard side of the aircraft), each in accordance with claim 1 (as discussed for claim 1)
the wingtip propulsion units (as already discussed for claim 1)
the lift-increase propulsion units (as discussed) being located between the fuselage of the aircraft and the wingtip propulsion units (Fig 2, 4).
Moxon’742 in view of Moxon’272, Himmelmann and Swann teaches, as discussed so far, teaches the wingtip prolusion unit but is silent about:
of the first and second propulsion systems being located respectively at the tip of the left wing and at the tip of the right wing, or inversely,
However, Moxon ‘272 teaches:
of the first and second propulsion systems being located respectively at the tip of the left wing and at the tip of the right wing (Fig. 2 of Moxon ‘272), or inversely,
Regarding claim 10, Moxon’742 in view of Moxon’272, Himmelmann and Swann teaches the invention as discussed for claim 9. Moxon’742 further teaches:
Aircraft (Figs. 1, 2, 4) according to the preceding claim, wherein:
the first propulsion system comprises at least two lift-increase propulsion units (Fig. 2 shows propulsion system and multiple propulsors 46, one located on the left and the other located on the right of the fuselage (the multiple propulsors 46 are connected to a bus 68 in “parallel”, and the bus 68 also connects both sides of the aircraft [0041-0042], therefore the propulsors can be grouped in systems that include propulsors on each side, or as desired),
these two lift-increase propulsion units being both electrically connected to the intermediate DC distribution stage (DC distribution stage discussed for claim 1) of the first propulsion system (the DC distribution system, as discussed for claim 1, would be connected to the bus 68 discussed above),
the second propulsion system comprises at least two lift- increase propulsion units (similar to the discussion above for the first propulsion system), one located on the left and the other located on the right of the fuselage (for the same reasons discussed above, the second propulsion system can be defined as comprising propulsors on each side, or as desired),
these two lift-increase propulsion units being both electrically connected to the intermediate DC distribution stage of the second propulsion system (the DC distribution system, as discussed for claim 1, and analogous to the discussion above).
Regarding claim 11, Moxon’742 in view of Moxon’272, Himmelmann and Swann teaches the invention as discussed for claim 9.
Moxon’742 teaches turboprops engines [0002, 0020], but Moxon’742 in view of Moxon’272, Himmelmann and Swann, as discussed so far, is silent about:
wherein the first propulsion system and the second propulsion system each comprise a turboprop,
the turboprop of the first propulsion system, which drives the generator of the first propulsion system, is located on the left of the fuselage while the wingtip propulsion unit of the first propulsion system is located at the tip of the right wing of the aircraft, and
the turboprop of the second propulsion system, which drives the generator of the second propulsion system, is located on the right of the fuselage, while the wingtip propulsion unit of the second propulsion system is located at the tip of the left wing of the aircraft
However, Moxon’272 teaches:
wherein the first propulsion system and the second propulsion system each comprise a turboprop (turboprop: [0002]; inter alia, 10, 9, 1-4, 106b, 130b, and the first and second propulsions systems have similar structure as seen in Fig. 2, one system on the left wing and the other system on the right wing),
the turboprop of the first propulsion system (left wing, Fig. 2), which drives the generator of the first propulsion system, is located on the left of the fuselage (Fig. 2 shows 2 propulsion systems as discussed above, one on the left wing and one on the right wing) while the wingtip propulsion unit of the first propulsion system is located at the tip of the right wing of the aircraft (Moxon’272 teaches in [0041]: “The interconnector 140 is an electrical connector which electrically couples the motor generators 116 of the left propulsor arrangement 100a, with the motor generators 116 of the right propulsor arrangement 100b. Consequently, in the event of a failure of the gas turbine engine 10 of one of the propulsor arrangements, power can be transferred from one propulsor arrangement 100a, 100b to the other electrically. For example, where the left propulsor arrangement 100a gas turbine engine 10 fails in flight, the motor generators 116 of the right propulsor arrangement 100b would be operated in a generator mode, while the motor generators 116 of the left propulsor arrangement 100a would be operated in a motor mode. Consequently, the propulsors 130a-c of the left propulsor arrangement 100a would continue to operate in OEI conditions” and “ Since the tip propulsors 134 are powered by electrical power provided by the interconnector 140, electrical power can continue to be provided during OEI operation“ [0044] – The first propulsion system can therefore be “defined” as comprising a mix of elements from 100a and 100b, in other words, the first propulsion system can be defined as comprising, inter alia, 100a’s elements 130a and 130b plus 100b’s elements 130c and 134 - located on the right wing), and
the turboprop of the second propulsion system (right wing, Fig. 2), which drives the generator of the second propulsion system, is located on the right of the fuselage, while the wingtip propulsion unit of the second propulsion system is located at the tip of the left wing of the aircraft (for the same reasons mentioned above for the first propulsion system, the second propulsion system can therefore be “defined” as comprising a mix of elements from 100a and 100b, in other words, the first propulsion system can be defined as comprising, inter alia, 100b’s elements 130a and 130b plus 100a’s elements 130c and 134 - located on the left wing).
Regarding claim 12, Moxon’742 in view of Moxon’272, Himmelmann and Swann teaches the invention as discussed for claim 9.
Moxon ‘742 further teaches that both sides of the aircraft, and the multiple propulsors in the system are interconnected, and the multiple propulsors 46 are connected to a bus 68 in “parallel”, and the bus 68 also connects both sides of the aircraft [0041-0042], therefore the propulsors can be grouped as desired and be powered by different sources connected to bus 68. However, Moxon’742 in view of Moxon’272, Himmelmann and Swann, as discussed so far, does not explicitly teach:
each wingtip propulsion unit and each lift-increase propulsion unit is electrically connected to the generator of the first propulsion system and to the generator of the second propulsion system so as to be electrically powered indifferently either by one or by the other of the two generators
Moxon’272 teaches:
each wingtip propulsion unit and each lift-increase propulsion unit is electrically connected to the generator of the first propulsion system and to the generator of the second propulsion system so as to be electrically powered indifferently either by one or by the other of the two generators (Moxon [0041-0044]).
Regarding claim 13, Moxon’742 in view of Moxon’272, Himmelmann and Swann teaches the invention as discussed for claims to any 2. Moxon’742 further teaches:
The propulsion system according to claim 2, wherein the alternating-current generator is driven by the turboprop (“a propulsion system comprising a pair of internal combustion engines (10) each driving an electrical power generator (56)” Abstract, and “turboprops” [0002, 0020]), and wherein all mechanical power produced by the turboprop and transmitted to the wingtip propulsion unit (as already discussed for claim 1, the wingtip propulsion units are electrically powered, and electrically interconnected to the rest of the system) and to the lift- increase propulsion unit is converted into electrical energy by the alternating current generator (“each electrical power generator (56) being electrically coupled to a plurality of electrically driven propulsors (46)” abstract).
Claim(s) 14 is/are rejected under 35 U.S.C. 103 as being unpatentable over Moxon 20160355272 (Moxon’272) in view of Moxon 20150144742 (Moxon’742) and Himmelmann 20180265206
Regarding claim 14, Moxon’742 teaches:
A propulsion system (“a propulsion system”, Abstract) for a non-rotary-wing aircraft (Figures 1, 2, 4), comprising:
a turboprop ([0002, 0020]),
an alternating-current generator (electrical power generator (56), Abstract), driven by the turboprop (“a propulsion system comprising a pair of internal combustion engines (10) each driving an electrical power generator (56)” abstract, turboprop discussed above),
at least one lift-increase propulsion unit (inter alia, 46; “the propulsors 46 substantially increase the amount of lift generated by the wings 44” [0036]), comprising one or more propellers (50) and an alternating-current motor whose sole power input is electrical energy (“Each propulsor 46 comprises an electric motor (not shown) housed within a nacelle 48“ [0035]) delivered through a second AC power supply circuit (“Main electrical bus 68” [0041]), the alternating-current motor of the lift-increase propulsion unit being a physical device distinct from the alternating-current generator (“Each electrical generator 56 is connected to a plurality of propulsors 46 on the respective wing by a main electrical bus 68” [0041]), wherein the one or more propellers are mechanically coupled to said alternating-current motor (Fig. 4) and are configured to operate selectively in either (i) a powered operation in which the one or more propellers are driven in rotation by the alternating-current motor (“Each propulsor 46 comprises an electric motor (not shown) housed within a nacelle 48, and a propeller 50 driven by the motor,” [0035]) and (ii) a non-powered operation in which said one or more propellers are rotated by incident airflow and back-drive the alternating-current motor as a generator to recover mechanical energy as electrical energy (aircraft propellers are known to inherently rotate by incidental airflow when not being powered by an engine/motor, unless additional steps are taken to prevent it – i.e., such as placing the propellers in a “feathered” position to avoid windmilling; electric motors are also known in the art to be capable of operating as generators when mechanical power is provided to the rotor, and producing electrical current/energy),
[[a]] the second AC power supply circuit, that electrically connects the generator to the lift-increase propulsion unit (as discussed above, [0041]),
wherein all mechanical power produced by the turboprop and transmitted
to the lift-increase propulsion unit is converted into electrical energy by the alternating current generator (“each electrical power generator (56) being electrically coupled to a plurality of electrically driven propulsors (46)” abstract), and
Moxon’742 is silent about:
at least one wingtip propulsion unit comprising an alternating-current motor, having a direction of rotation that opposes formation of wingtip vortices,
a first AC power supply circuit, that electrically connects the alternating-current generator to the at least one wingtip propulsion unit,
[wherein all mechanical power produced by the turboprop and] transmitted to the wingtip propulsion unit is converted into electrical energy
However, Moxon’272 teaches an aircraft propulsion system (title), and:
at least one wingtip propulsion unit comprising an alternating-current motor (“Each propulsor 134 is driven by an electric motor 138, which is provided with electrical power from the motor generators 116 “, [0043]), having a direction of rotation that opposes formation of wingtip vortices (“By rotating the propellers in a clockwise direction as viewed from downstream of the propulsor 134 on the port wing 34, and in an opposite direction on the starboard wing, the wingtip vortex can be at least partly cancelled, thereby reducing the wake vortex.” Moxon [0043),
a first AC power supply circuit (inter alia, electrical interconnector 140 [0043]), that electrically connects the alternating-current generator (in the case of Moxon’272, the generator are represented by 116, however, as discussed above, the generators in the combination are already taught by the base reference Moxon’742; Moxon’272 is used here to teach the first AC power supply) to the at least one wingtip propulsion unit (Fig. 3),
[wherein all mechanical power produced by the turboprop and] transmitted to the wingtip propulsion unit [is converted into electrical energy] (“Each propulsor 134 is driven by an electric motor 138, which is provided with electrical power from the motor generators“, [0043])
It would have been obvious to a person having ordinary skills in the art before the effective filing date of the claimed invention to provide Moxon’742 with Moxon’272's structure discussed above, so “the tip propulsors 134 are located at a point where a wingtip vortex would normally be generated” because “rotating the propellers in a clockwise direction as viewed from downstream of the propulsor 134 on the port wing 34, and in an opposite direction on the starboard wing, the wingtip vortex can be at least partly cancelled, thereby reducing the wake vortex” [0043].
Moxon’742 in view of Moxon’272' is silent about the elements within second power supply as claimed:
wherein the second AC power supply circuit comprises:
an intermediate DC distribution stage,
one or more electric batteries connected to said intermediate DC distribution stage,
an AC/DC converter, that electrically connects the generator to said intermediate DC distribution stage, and
a DC/AC converter, that electrically connects said intermediate stage to the lift-increase propulsion unit,
wherein the first AC power supply circuit is configured to deliver an AC current produced by the generator, to the wingtip propulsion unit, without intermediate conversion of this alternating current into direct current,
wherein the intermediate DC distribution stage is electrically connected in series between the DC/AC converter and the AC/DC converter, and the DC/AC converter constitutes the sole electrical input to each alternating-current motor driving the one or more propellers of the lift-increase propulsion unit
However, Himmelmann teaches an AC system for an aircraft (Title, abstract), the system with an AC direct power connection (114) and a second circuit, a DC bus 115 which permits the inclusion of an energy storage device ([0017]) and:
an intermediate DC distribution stage (115),
one or more electric batteries (112) connected to said intermediate DC distribution stage (Fig 1)
an AC/DC converter (Bi-directional inverter-rectifiers 108 and 109 are bi-directional rectifiers and inverters insomuch as they can transmit and rectify power in either direction [0014]), that electrically connects the generator (106) to said intermediate DC distribution stage (Fig 1), and
a DC/AC converter (Bi-directional inverter-rectifiers 108 and 109), that electrically connects said intermediate stage to the lift-increase propulsion unit (Fig 1, where, inter alia, 111 is part of a lift-increase propulsion unit),
and wherein the intermediate DC distribution stage is electrically connected in series between the DC/AC converter and the AC/DC converter (Fig. 1 shows 115 between 109 and 108), and the DC/AC converter constitutes the sole electrical input to each alternating-current motor driving the one or more propellers of the lift-increase propulsion unit (Fig. 1 shows input to 111 as being provided by 109 when power contactor assembly 114 is disconnected [0016], the system is therefore operable with DC/AC converter as the sole electrical input to the motor)
It would have been obvious to a person having ordinary skill the art before the effective filing date of the claimed invention to provide Moxon’742 in view of Moxon’272' with Himmelmann's teachings discussed above in order to have a second power supply circuit to provide electrical power to “an electric propulsion motor is configured to receive the electric power and be selectively driven at an operational speed independent of a rotational speed of the power shaft” as taught by Himmelmann (abstract), and allows for power to be provided by the DC circuit, from the energy storage device, if the gas turbine engine is not operating [0021].
Moxon’742 in view of Moxon’272 and Himmelmann teaches:(ii) configured, during non-powered operation, to rotate in response to airflow so as to back-drive the alternating-current motor to recover mechanical energy as electrical energy, as discussed above, since these features are part of these systems. However, to clear any doubt, Swann also teaches the limitations:
Swann teaches an electrically-assisted propulsion control system, with a propulsive fan 220 attached to a motor/generator 224 (Col 10 ll. 59), and:
(ii) configured, during non-powered operation, to rotate in response to airflow so as to back-drive the alternating-current motor to recover mechanical energy as electrical energy (In the descent phase of flight, the engine 210 is in its unlit or idle state. The fan 222 of the propulsive fan 220 (if present) is being driven (“windmilling”) by air-flow resulting from the forward motion of the aircraft, and as a result is causing the generator 224 to generate electrical energy which is used to charge the energy storage unit 200. Additionally or alternatively, the co-located fan 212 of the engine 210 can be used in a “wind-milling” capacity to charge the energy storage unit 200 with electrical energy generated by the generator 214/217” (Col 12, ll. 33-49)).
It would have been obvious to a person having ordinary skills in the art before the effective filing date of the claimed invention to provide Moxon’742 in view of Moxon’272 and Himmelmann with Swann's teachings discussed above because this would advantageously allow aircraft speed to be regulated in support of steeper descents without the need to configure the aerofoils of the aircraft wing into a high-drag high-noise configuration” (Col 12, ll. 33-49).
Claim(s) 5 and 6 is/are rejected under 35 U.S.C. 103 as being unpatentable over Moxon 2050144742 (Moxon’742) in view of Moxon 20160355272 (Moxon’272), Himmelmann 20180265206, Swann 11260983 (from now on referred to as Swann’983) and Swann 20160304211 (Swann’211).
Regarding claim 5, Moxon’742 in view of Moxon’272, Himmelmann and Swann’983 teaches the invention as discussed above for claim 1. Moxon’742 in view of Moxon’272, Himmelmann and Swann’983 is silent about:
further comprising an electronic control unit that comprises at least one processor and one memory, the control unit being programmed to, during a flight of the aircraft comprising a take-off phase, a cruising phase and a landing phase, control the motor of the lift-increase propulsion unit in such a way that this propulsion unit:
delivers a mechanical propulsion power in the take-off or landing phase,
but remains off during most of the cruising phase
However, Swann’211 teaches and aircraft propulsion system (title), and:
comprising an electronic control unit (controller, Abstract) that comprises at least one processor and one memory,
the control unit being programmed to, during a flight of the aircraft comprising, inter alia, a take-off phase, a cruising phase and a landing phase, control the motor of the lift-increase propulsion unit (a controller for varying the supply of power to the electric motor selectively from the generator and/or energy store in dependence on one or more property of a vapour trail resulting from the engine exhaust flow. [0012, 0114], a controller selectively varies the supply of power to the electric motor from the generator and/or energy store in dependence on one or more property of a vapour trail resulting from the engine exhaust flow. The controller may also control the supply of power to the energy store for charging - Abstract) in such a way that this propulsion unit:
-delivers a mechanical propulsion power in the take-off or landing phase, - but remains off during most of the cruising phase (The energy storage unit may be required to deliver energy to the propulsive fan(s) at certain points of the flight as standard (for example during take-off, climb-out, top-of-climb, step-climbs) in order to supplement the power being delivered by the one or more engine. [0114] – examiner notes that that the energy storage delivering energy to the propulsive fan at the specific flight phases listed above, is equivalent to the claimed “lift-increase propulsion unit” being in operation).
It would have been obvious to a person having ordinary skill the art before the effective filing date of the claimed invention to provide Moxon’742 in view of Moxon’272, Himmelmann and Swann’983 with Swann’211's teachings discussed above, such that “a controller selectively varies the supply of power to the electric motor from the generator and/or energy store in dependence on one or more property of a vapour trail resulting from the engine exhaust flow. The controller may also control the supply of power to the energy store for charging” as taught by Swann’211 (Abstract).
Regarding claim 6, Moxon’742 in view of Moxon’272, Himmelmann, Swann’983 with Swann’211 teaches the invention as discussed for claim 5.
Moxon’742 in view of Moxon’272, Himmelmann, Swann’983 with Swann’211, as discussed so far, is silent about:
the control unit of the propulsion system is further programmed to, during most of the flight of the aircraft, control the motor of the wingtip propulsion unit to deliver a mechanical propulsion power
However, Moxon’272 further teaches:
the control unit of the propulsion system is further programmed to, during most of the flight of the aircraft, control the motor of the wingtip propulsion unit to deliver a mechanical propulsion power (“The system may comprise a tip propulsor controller configured to control thrust generated by the tip propulsor in accordance with a yaw demand. Advantageously, the tip propulsor can be used to provide yaw control” [0015]).
Claim(s) 7 is/are rejected under 35 U.S.C. 103 as being unpatentable over Moxon 20160355272 (Moxon’272) in view of Moxon 2050144742 (Moxon’742) and Himmelmann 20180265206, Swann 11260983 and Kanerva 20130336818.
Regarding claim 7, Moxon’272 in view of Moxon’742, Himmelmann teaches the invention as discussed above. Moxon’272 in view of Moxon’742, Himmelmann, is silent about:
Propulsion system according to any preceding claim, wherein the lift-increase propulsion unit comprises a fixed-pitch propeller.
However, Kanerva teaches:
a fixed-pitch propeller (Both the first propeller and the second propeller may have fixed pitch [0079]).
It would have been obvious to a person having ordinary skill the art before the effective filing date of the claimed invention to provide Moxon’272 in view of Moxon’742, Himmelmann and Swann with Kanerva 's structure discussed above in order to provide the propulsion system with a fixed-pitch propeller to reduce weight and complexity.
Claim(s) 8 is/are rejected under 35 U.S.C. 103 as being unpatentable over Moxon 2050144742 (Moxon’742) in view of Moxon 20160355272 (Moxon’272) Himmelmann 20180265206, Swann 11260983 and Edwards 20160340051.
Regarding claim 8, Moxon’742 in view of Moxon’272, Himmelmann and Swann teaches the invention as discussed above. Moxon’742 in view of Moxon’272, Himmelmann, and Swann is silent about: Propulsion system according to any preceding claim, wherein the wingtip propulsion unit comprises a variable-pitch propeller.
However, Edwards teaches a propulsion system according to any preceding claim, wherein the wingtip propulsion unit comprises a variable-pitch propeller ([0013-0014])
It would have been obvious to a person having ordinary skill the art before the effective filing date of the claimed invention to provide Moxon’272 in view of Moxon’742', Himmelmann and Swann with Edwards' structure discussed above in order to provide a variable pitch propeller that can be adjusted to fine pitch because “With the propeller pitch at fine pitch, the inventors have found during experiments that the load applied to the drive motor is approximately 10% of the maximum load when the propeller is in coarse pitch” as taught by Edwards [0014].
Claim(s) 15 is/are rejected under 35 U.S.C. 103 as being unpatentable over Moxon 2050144742 (Moxon’742) in view of Moxon 20160355272 (Moxon’272) and Himmelmann 20180265206, Ribeiro20190375512 and Sanders 20210070458.
Regarding claim 15, Moxon’742 in view of Moxon’272, Himmelmann and Swann teaches the invention as discussed for claim 1. Moxon ‘742 further teaches:
The propulsion system according to claim 1, further comprising a turboprop ([0002, 0020]) configured to drive the alternating-current generator (electrical power generator (56), Abstract), during a flight of the aircraft having at least a taxi phase, a take-off phase, a cruising phase, a descent phase, and a landing phase (known in art as phases of flight):
electrically power the alternating-current motor of the lift-increase propulsion unit from the one or more electric batteries through the DC/AC converter, while the turboprop is off (“provide power to the propulsors for a short period on engine failure” [0037]);
during the take-off phase (takeoff [0037]) and the landing phase (landing phase included in scenarios where improved performance may be needed, or in case of engine failure [0037]), electrically power the alternating-current motor of the lift-increase propulsion unit at least in part from the one or more electric batteries through the DC/AC converter (“An electrical energy storage device such as a capacitor, chemical battery” [0037]; converters already discussed above, and it is noted that Himmelmann also teaches “energy storage device 112 may be a battery, a battery bank” [0027), and electrically power the alternating-current motor of the at least one wingtip propulsion unit through the first AC power supply
circuit (wingtip propulsion unit is connected to the electric circuit as already discussed);
during most of the cruising phase, while electrically powering the alternating-current motor of the at least one wingtip propulsion unit through the first AC power supply circuit (wingtip propulsion unit is powered as discussed for claim 1);
Moxon’742 in view of Moxon’272, Himmelmann and Swann’983, as discussed so far, is silent about:
an electronic control unit comprising at least one processor and one memory, wherein the electronic control unit is programmed
during the taxi phase, [electrically power the alternating-current motor of the lift-increase propulsion unit from the one or more electric batteries through the DC/AC converter],
during most of the cruising phase, keep the alternating-current motor of the lift-increase propulsion unit off
[during at least a portion of the descent phase,] operate the lift-increase propulsion unit in the non-powered operation such that mechanical energy recovered from incident airflow on the one or more propellers is stored as electrical energy in the one or more electric
batteries via the DC/AC converter and the intermediate DC distribution stage.
However, Ribeiro teaches a hybrid electric systems (title) with an electric machine connected to the propulsor gearbox in parallel to the gas turbine (abstract), allowing both gas turbine and electric machine to power the propulsor, and:
an electronic control unit comprising at least one processor and one memory, wherein the electronic control unit is programmed (“one or more electronic controllers 20 control the operating modes of the various described components. Such controller(s) 20 may execute program instructions stored in non-transitory memory, or they may be implemented as programmable gate arrays or other programmed logic circuitry” [0038])
during the taxi phase, electrically power the alternating-current motor of the propulsion unit (“During taxi-out, controller 20 operates switch 11 so that battery 8 and/or APU 9 and S/G 10 powers electric machine 3 operating in the motor mode […] The gas turbine engine 1 remains off during this time, but the the electric machine 3 powers propulsor 5 to supply forward thrust to move the aircraft forward on the taxiway” [0039]) from the one or more electric batteries through the DC/AC converter (circuit discussed above),
It would have been obvious to a person having ordinary skill the art before the effective filing date of the claimed invention to provide Moxon’742 in view of Moxon’272', Himmelmann and Swann’983 with Ribeiro's teachings discussed above, to during the taxi phase, electrically power the alternating-current motor of the lift-increase propulsion unit, to move the aircraft, because “The propulsor driven electric taxi has the potential to decrease the Block Fuel consumption of the aircraft, increasing the aircraft efficiency and competitiveness” as taught by Ribeiro [0047].
Moxon’742 in view of Moxon’272', Himmelmann and Swann’983 and Ribeiro, as discussed so far, is silent about:
[during most of the cruising phase,] keep the alternating-current motor of the lift-increase propulsion unit off
[during at least a portion of the descent phase,] operate the lift-increase propulsion unit in the non-powered operation such that mechanical energy recovered from incident airflow on the one or more propellers is stored as electrical energy in the one or more electric batteries via the DC/AC converter and the intermediate DC distribution stage.
However, Sanders Teaches a hybrid-electric power plant, “hybrid-electric power plant includes a heat engine operatively connected to a first air mover, and an electric motor operatively connected to a second air mover” (abstract), and:
during most of the cruising phase, keep the alternating-current motor of the lift-increase propulsion unit off (“method includes freewheeling the second air mover during the cruise stage” abstract) and/or the descent stage to generate mechanical energy
[during at least a portion of the descent phase,] operate the lift-increase propulsion unit in the non-powered operation such that mechanical energy recovered from incident airflow on the one or more propellers (“method includes freewheeling the second air mover during the cruise stage and/or the descent stage to generate mechanical energy” abstract) is stored as electrical energy in the one or more electric
batteries via the DC/AC converter and the intermediate DC distribution stage (circuit as already discussed above).
It would have been obvious to a person having ordinary skills in the art before the effective filing date of the claimed invention to provide Moxon’742 in view of Moxon’272', Himmelmann and Swann’983 and Ribeiro with Sanders’ structure discussed above in order “to generate mechanical energy” as taught by Sanders (abstract).
Response to Arguments
Applicant’s arguments filed on 6/12/2026 regarding the base reference Moxon’742 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
Additional Applicant’s arguments been considered, but they are not persuasive. However, to the extent possible, applicant’s arguments have been addressed in the body of the rejections above, at the appropriate location.
Applicant argues on page 16:
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Examiner’s response: Examiner respectfully disagrees with applicant, Himmelman is used because of its teachings of the DC/AC converters and distribution system as discussed in the claim, and not to teach the entire electrical distribution architecture, one of ordinary skill in the art would understand that the teachings would apply to the multiple portions of the system, the circuitry being repeated as appropriate in a dual-architeture (or multiple) system.
Applicant argues on page 17:
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Examiner’s response: examiner respectfully disagrees, the concept of windmilling, as the name states, is widely known and used in windmills (known for at least centuries), and is known in the art and applies to various propellers, including propeller driven aircraft propulsors as seen in Swan’983 and Moxon’242, and also in helicopters (autorotation), and wind turbines. Furthermore, pinwheels also use similar principles and are widely known.
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.
Correspondence
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Roberto T. Igue whose telephone number is (303)297-4389. The examiner can normally be reached Monday-Friday 7:30-4:30 PT.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Phutthiwat Wongwian can be reached on (571) 270-5426. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/ROBERTO TOSHIHARU IGUE/ Examiner, Art Unit 3741
/PHUTTHIWAT WONGWIAN/ Supervisory Patent Examiner, Art Unit 3741
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