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
This action is in reply to the patent application filed on January 21, 2026.
Claims 1-5, 7-13, 15-18, and 20 are currently pending and have been examined.
Claims 6, 14, and 19 have been canceled by the applicant.
This action is made FINAL.
The examiner would like to note that this application is being handled by examiner Christine Huynh.
Response to Arguments
Applicant's arguments filed January 21, 2026 have been fully considered but they are not persuasive. With respect to the 35 U.S.C. 103 rejection of claim 1, the applicant argues that there is no teaching or suggestion in Munevar that the alleged motor control unit operates in a normal mode to convert "DC electric power supplied to the electrical distribution system from the battery or generator" and outputs "AC electrical power and supply the output AC electrical power to the electric motor" (page 9). However, the examiner disagrees, because Munevar in combination with Harwood teaches "DC electric power supplied to the electrical distribution system from the battery or generator" and outputs "AC electrical power and supply the output AC electrical power to the electric motor". Hardwood teaches (“According to a first aspect there is provided a vehicle propulsion system comprising: at least first and second electrical generators, each being configured to provide AC electrical power to a respective first and second AC electrical network; at least first and second AC electrical motors directly electrically coupled to a respective AC network and coupled to a respective propulsor” (col 1, lines 43-50)), where the electrical generator provides AC electrical power, Hardwood further teaches (“The DC network 18 further comprises an energy storage device in the form of a battery 22,” (col 4, lines 58-59), “The propulsion system 10 can be operated in one of three distinct operating modes. In a first mode, both generators 15a, 15b are operative, and the converters 17a, 17b are operated in the AC to DC mode. The battery 22 and DC-DC converter 23 may be in either a charging or discharging mode, depending on the state of charge of the battery, and electrical power requirements of the motors 19a-d. At least the switches interconnecting the converter 17a and inverter 21a, and the converter 17b and inverter 21b are closed. Consequently, AC electrical power at the generator frequency is provided to the directly coupled motors 19a, 19b.” (col 5, lines 27-43), where it is shown that the DC electric power is supplied to the electrical distribution system from a DC battery. Therefore, Munevar, which teaches modes including a normal and hoteling mode of the aircraft, in combination with the AC-DC conversion aircraft propulsion system of Hardwood teaches the rotational assembly by controlling the motor control unit to convert the electrical power supplied to the electrical distribution system from the battery or generator and output DC electrical power and supplying the output DC electrical power to the AC electric motor. Similar independent claims 9 and 15 are rejected for the same reasons as above. Accordingly, the 35 U.S.C. 103 rejection is maintained. See detailed rejection below.
Applicant’s arguments with respect to claim(s) 15 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. Applicant argues that Munevar in combination with Hardwood does not teach the amended claim limitation “…the AC electric motor including a rotor directly coupled to the second shaft…” and “wherein the bladed power turbine rotor is arranged between the rotor of the AC electric motor and the bladed turbine rotor”. Upon further search and consideration, the amended claim 15 is rejected under 35 U.S.C. 103 as being unpatentable over Munevar (US 20170260872 A1) in view of Harwood et al. (US 11542021 B2) and Osama et al. (US 20220003128 A1). See detailed rejection below.
Dependent claims are rejected for the same reasons as listed above due to dependency. See detailed rejection below.
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) 1-5 and 7-13 is/are rejected under 35 U.S.C. 103 as being unpatentable over Munevar (US 20170260872 A1) in view of Harwood et al. (US 11542021 B2), which was provided in the IDS sent on June 14, 2024.
Regarding claims 1-5 and 7-13:
With respect to claim 1, Munevar teaches:
a propulsor; (“Vehicles such as aircraft have different modes of operation. In a first mode (also called normal mode), a propulsor (e.g., a propeller, rotor, or fan) of a gas turbine engine rotates and provides the necessary thrust to move the vehicle.” [0015])
a gas turbine engine including a rotational assembly configured for rotation about a rotational axis of the gas turbine engine, the rotational assembly including a bladed power turbine rotor and a shaft, the shaft operably connecting the bladed power turbine rotor and the propulsor; (“For example, the electrical generator includes a motor rotor, where the motor rotor includes a shaft. The motor rotor may be mechanically coupled to gear trains, for example through splined shafts, or may be electromechanically coupled to the drive shaft (e.g., low pressure shaft) of respective engines 14. In some examples, the engine drive shafts, such as a low pressure shaft or a high pressure shaft, may include integrated electrical generators (e.g., in which the rotor of the electrical generator is integrated in the low pressure shaft or high pressure shaft).” [0031]), and FIG. 2, which shows a gas turbine engine including a first and a second rotational assembly.
an electrical assembly including an alternating current (AC) electric motor, a battery, a generator, a motor control unit, and an electrical distribution system, the AC electric motor coupled to the rotational assembly, the motor control unit electrically connected to the AC electric motor and the electrical distribution system, the battery and the generator electrically connected to the electrical distribution system, the motor control unit selectively operable in a normal mode and a hotel mode, the motor control unit including a processor connected in signal communication with non-transitory memory containing instructions, (“using an electronic brake that is implemented with a generator (e.g., electrical motor) and drive and generator control system (e.g., unit that controls the power electronics) to provide electromotive forces needed for the generator to slow down or stop the rotation of the propulsor. Because the motor rotor of the electrical motor is stopped or slowed down, the electrical motor may not generate any additional power.” [0021], “During a first mode of operation, such as normal operation where the engine is causing a device to move, the rotation of the propeller, rotor, or fan provides the electrical generator with the mechanical power to generate electrical power. During a second mode of operation, such as hoteling mode where reduced thrust is desired, the electrical generator may function as an electrical motor and apply a torque in opposite direction of rotation of the propeller, rotor, or fan, which reduces the rotation speed or stops the propeller, rotor, or fan. In some examples, a controller may increase the resistance on the output of the electrical generator, which increases the torque needed to rotate a motor rotor of the electrical motor, which in turn reduces the speed or stops the propeller, rotor, or fan.” [0014], “during hoteling mode, the electrical motor applies torque in a second, opposite direction to the rotational direction of propulsor to cause rotation of the propulsor to slow. If the counter-torque is equal to the force from the propulsor, the propulsor stops moving.” [0033], “there may be additional electrical generators or other types of power sources such as batteries that provide power to drive and generator control system 26 during the hoteling mode.” [0062], “The output of power electronics 50 is a voltage or current to electrical motor 24 that causes electrical motor 24 to generate the counter-torque on motor rotor shaft 22 to stop or slow down the rotation of propulsor 18. Processor 52 determines the voltage or current level of the voltage or current that power electronics 50 is to provide electrical motor 24. Examples of processor 52 include one or more microprocessors, application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), digital signal processors (DSPs), or other equivalent integrated or discrete logic circuitry.” [0065]), where there is an electrical assembly that includes an electric motor, battery, a motor control unit, and an electrical distribution system, and the motor is coupled to a rotational assembly. This also shows that the motor is operable in a normal mode and a hoteling mode.
in the normal mode, control the motor control unit to convert direct current (DC) electrical power supplied to the electrical distribution system from the battery or generator and output AC electrical power and supply the output AC electrical power to the electric motor; (“During a first mode of operation, such as normal operation where the engine is causing a device to move, the rotation of the propeller, rotor, or fan provides the electrical generator with the mechanical power to generate electrical power.” [0014]).
While Munevar teaches an electric motor, it does not specify if it is an AC electric motor. However, Harwood teaches (“According to a first aspect there is provided a vehicle propulsion system comprising: at least first and second electrical generators, each being configured to provide AC electrical power to a respective first and second AC electrical network; at least first and second AC electrical motors directly electrically coupled to a respective AC network and coupled to a respective propulsor” (col 1, lines 43-50)), where the electrical generator provides AC electrical power. Harwood further teaches (“The DC network 18 further comprises an energy storage device in the form of a battery 22,” (col 4, lines 58-59), “The propulsion system 10 can be operated in one of three distinct operating modes. In a first mode, both generators 15a, 15b are operative, and the converters 17a, 17b are operated in the AC to DC mode. The battery 22 and DC-DC converter 23 may be in either a charging or discharging mode, depending on the state of charge of the battery, and electrical power requirements of the motors 19a-d. At least the switches interconnecting the converter 17a and inverter 21a, and the converter 17b and inverter 21b are closed. Consequently, AC electrical power at the generator frequency is provided to the directly coupled motors 19a, 19b.” (col 5, lines 27-43), where it is shown that the DC electric power is supplied to the electrical distribution system from a DC battery. Therefore, Munevar, which teaches modes including a normal and hoteling mode of the aircraft, in combination with the AC-DC conversion aircraft propulsion system of Hardwood teaches the rotational assembly by controlling the motor control unit to convert the electrical power supplied to the electrical distribution system from the battery or generator and output DC electrical power and supplying the output DC electrical power to the AC electric motor.
in the hotel mode, apply a braking force to the rotational assembly by controlling the motor control unit to convert the DC electrical power supplied to the electrical distribution system from the battery or generator and output DC electrical power and supplying the output DC electrical power to the AC electric motor; (“During a second mode of operation, such as hoteling mode where reduced thrust is desired, the electrical generator may function as an electrical motor and apply a torque in opposite direction of rotation of the propeller, rotor, or fan, which reduces the rotation speed or stops the propeller, rotor, or fan. In some examples, a controller may increase the resistance on the output of the electrical generator, which increases the torque needed to rotate a motor rotor of the electrical motor, which in turn reduces the speed or stops the propeller, rotor, or fan.” [0014]), where the rotational assembly is used to brake the propulsor.
While Munevar teaches an electric motor, it does not teach supplying output DC electrical power to the AC electric motor. However, Harwood teaches (“The first and/or second AC to DC converters may comprise bi-directional AC to DC converters configured to provide AC electrical power from the AC network to DC electrical power to the DC network, and DC electrical power from the DC network to AC electrical power to the AC electrical network.” (col 2, lines 6-11)), where DC electrical power can be supplied to the AC electrical network. Harwood further teaches (“The DC network 18 further comprises an energy storage device in the form of a battery 22,” (col 4, lines 58-59), “The propulsion system 10 can be operated in one of three distinct operating modes. In a first mode, both generators 15a, 15b are operative, and the converters 17a, 17b are operated in the AC to DC mode. The battery 22 and DC-DC converter 23 may be in either a charging or discharging mode, depending on the state of charge of the battery, and electrical power requirements of the motors 19a-d. At least the switches interconnecting the converter 17a and inverter 21a, and the converter 17b and inverter 21b are closed. Consequently, AC electrical power at the generator frequency is provided to the directly coupled motors 19a, 19b.” (col 5, lines 27-43), where it is shown that the DC electric power is supplied to the electrical distribution system from a DC battery. Therefore, Munevar, which teaches modes including a normal and hoteling mode of the aircraft, in combination with the AC-DC conversion aircraft propulsion system of Hardwood teaches the rotational assembly by controlling the motor control unit to convert the electrical power supplied to the electrical distribution system from the battery or generator and output DC electrical power and supplying the output DC electrical power to the AC electric motor.
It would have been obvious to one of ordinary skill in the art before the effective filling date of the instant application to have combined Munevar’s propulsion system with Harwood’s AC and DC electrical systems because (“Advantageously, the first and second directly electrically coupled motors efficiently provide propulsive thrust in view of the low losses provided by wholly AC electrical systems, while thrust control can be provided utilising the one or more electrical motors coupled to the DC electrical network, without requiring either power electronics or control of the frequency of the AC networks. Consequently, the invention provides an efficient yet controllable aircraft propulsion system.” (col 1, lines 56-64)).
With respect to claim 9, Munevar teaches:
rotating a first rotational assembly of a gas turbine engine, the first rotational assembly including a bladed compressor rotor, a bladed turbine rotor, and a first shaft interconnecting the bladed compressor rotor and the bladed turbine rotor; (“For example, the electrical generator includes a motor rotor, where the motor rotor includes a shaft. The motor rotor may be mechanically coupled to gear trains, for example through splined shafts, or may be electromechanically coupled to the drive shaft (e.g., low pressure shaft) of respective engines 14. In some examples, the engine drive shafts, such as a low pressure shaft or a high pressure shaft, may include integrated electrical generators (e.g., in which the rotor of the electrical generator is integrated in the low pressure shaft or high pressure shaft).” [0031]), and FIG. 2, which shows a gas turbine engine including a first rotational assembly.
controlling rotation of a propulsor of the aircraft propulsion system with a second rotational assembly of the gas turbine engine, the second rotational assembly including a bladed power turbine rotor and a second shaft, the second shaft operably connecting the bladed turbine rotor and the propulsor; (“In a gas turbine engine, the propulsor is coupled to a shaft (e.g., a low pressure shaft, as described below) such that the rotation of the shaft causes the propulsor to rotate. In this disclosure, the example techniques may stop or slow down the rotation of the shaft, and the shaft is coupled to propulsor meaning that stopping or slowing down the shaft stops or slows down the rotation of the propulsor.” [0019]), showing that the propulsor is controlled with a second rotational assembly, and FIG. 2, which shows a gas turbine engine including a second rotational assembly that is operably connected to the bladed turbine rotor and the propulsor.
applying a braking force to the second rotational assembly with an alternating current (AC) electric motor of an electrical assembly of the aircraft propulsion system, the electrical assembly including a battery and a motor control unit, the motor control unit electrically connected to the AC electric motor and the battery, applying the braking force to the second rotational assembly with the AC electric motor including supplying direct current (DC) electrical power to the motor control unit with the battery and supplying an output DC electrical power to the AC electric motor with the motor control unit concurrent with rotating the first rotational assembly; (“using an electronic brake that is implemented with a generator (e.g., electrical motor) and drive and generator control system (e.g., unit that controls the power electronics) to provide electromotive forces needed for the generator to slow down or stop the rotation of the propulsor. Because the motor rotor of the electrical motor is stopped or slowed down, the electrical motor may not generate any additional power.” [0021], “During a second mode of operation, such as hoteling mode where reduced thrust is desired, the electrical generator may function as an electrical motor and apply a torque in opposite direction of rotation of the propeller, rotor, or fan, which reduces the rotation speed or stops the propeller, rotor, or fan. In some examples, a controller may increase the resistance on the output of the electrical generator, which increases the torque needed to rotate a motor rotor of the electrical motor, which in turn reduces the speed or stops the propeller, rotor, or fan.” [0014], “during hoteling mode, the electrical motor applies torque in a second, opposite direction to the rotational direction of propulsor to cause rotation of the propulsor to slow. If the counter-torque is equal to the force from the propulsor, the propulsor stops moving.” [0033], “there may be additional electrical generators or other types of power sources such as batteries that provide power to drive and generator control system 26 during the hoteling mode.” [0062]), where the rotational assembly is used to brake the propulsor.
While Munevar teaches an electric motor, it does not specify if it is an AC electric motor or teach supplying output DC electrical power to the AC electric motor. However, Harwood teaches (“According to a first aspect there is provided a vehicle propulsion system comprising: at least first and second electrical generators, each being configured to provide AC electrical power to a respective first and second AC electrical network; at least first and second AC electrical motors directly electrically coupled to a respective AC network and coupled to a respective propulsor” (col 1, lines 43-50)), where the electrical generator provides AC electrical power, and (“The first and/or second AC to DC converters may comprise bi-directional AC to DC converters configured to provide AC electrical power from the AC network to DC electrical power to the DC network, and DC electrical power from the DC network to AC electrical power to the AC electrical network.” (col 2, lines 6-11)), where DC electrical power can be supplied to the AC electrical network. Harwood further teaches (“The DC network 18 further comprises an energy storage device in the form of a battery 22,” (col 4, lines 58-59), “The propulsion system 10 can be operated in one of three distinct operating modes. In a first mode, both generators 15a, 15b are operative, and the converters 17a, 17b are operated in the AC to DC mode. The battery 22 and DC-DC converter 23 may be in either a charging or discharging mode, depending on the state of charge of the battery, and electrical power requirements of the motors 19a-d. At least the switches interconnecting the converter 17a and inverter 21a, and the converter 17b and inverter 21b are closed. Consequently, AC electrical power at the generator frequency is provided to the directly coupled motors 19a, 19b.” (col 5, lines 27-43), where it is shown that the DC electric power is supplied to the electrical distribution system from a DC battery. Therefore, Munevar, which teaches modes including a normal and hoteling mode of the aircraft, in combination with the AC-DC conversion aircraft propulsion system of Hardwood teaches the rotational assembly by controlling the motor control unit to convert the electrical power supplied to the electrical distribution system from the battery or generator and output DC electrical power and supplying the output DC electrical power to the AC electric motor.
It would have been obvious to one of ordinary skill in the art before the effective filling date of the instant application to have combined Munevar’s propulsion system with Harwood’s AC and DC electrical systems because (“Advantageously, the first and second directly electrically coupled motors efficiently provide propulsive thrust in view of the low losses provided by wholly AC electrical systems, while thrust control can be provided utilising the one or more electrical motors coupled to the DC electrical network, without requiring either power electronics or control of the frequency of the AC networks. Consequently, the invention provides an efficient yet controllable aircraft propulsion system.” (col 1, lines 56-64)).
With respect to claims 2 and 10, Munevar in combination with Harwood, as shown in the rejection above, discloses the limitations of claims 1 and 9. The combination of Munevar and Harwood teaches an aircraft propulsion system of claims 1 and 9. Munevar further teaches:
wherein the instructions, when executed by the processor, cause the processor to control a magnitude of the braking force, in the hotel mode, by modulating one or both of a current or a voltage of the output DC electrical power; (“The output of power electronics 50 is a voltage or current to electrical motor 24 that causes electrical motor 24 to generate the counter-torque on motor rotor shaft 22 to stop or slow down the rotation of propulsor 18. Processor 52 determines the voltage or current level of the voltage or current that power electronics 50 is to provide electrical motor 24.” [0065], “Processor 52 may utilize the position of LP shaft 42 (or possibly the position of LP shaft 42 at different times) as an input into the position control laws algorithm and determine the current or voltage that power electronics 50 is to apply. For instance, if LP shaft 42 is rotating faster than the desired setpoint, processor 52 may determine that there should be an increase in the current or voltage that power electronics 50 outputs to increase the electromotive force that electrical motor 24 applies via motor rotor shaft 22.” [0067]), which shows controlling a magnitude of the braking force by controlling the current of the output power.
While Munevar teaches an electric motor, it does not teach supplying output DC electrical power to the AC electric motor. However, Harwood teaches (“The first and/or second AC to DC converters may comprise bi-directional AC to DC converters configured to provide AC electrical power from the AC network to DC electrical power to the DC network, and DC electrical power from the DC network to AC electrical power to the AC electrical network.” (col 2, lines 6-11)), where DC electrical power can be supplied to the AC electrical network.
It would have been obvious to one of ordinary skill in the art before the effective filling date of the instant application to have combined Munevar’s propulsion system with Harwood’s AC and DC electrical systems because (“Advantageously, the first and second directly electrically coupled motors efficiently provide propulsive thrust in view of the low losses provided by wholly AC electrical systems, while thrust control can be provided utilising the one or more electrical motors coupled to the DC electrical network, without requiring either power electronics or control of the frequency of the AC networks. Consequently, the invention provides an efficient yet controllable aircraft propulsion system.” (col 1, lines 56-64)).
With respect to claims 3 and 11, Munevar in combination with Harwood, as shown in the rejection above, discloses the limitations of claims 2 and 10. The combination of Munevar and Harwood teaches an aircraft propulsion system of claims 2 and 10. Munevar further teaches:
wherein the instructions, when executed by the processor, cause the processor to increase the magnitude of the braking force, in the hotel mode, by modulating one or both of the current or the voltage in response to identifying a rotation speed of the propulsor greater than a rotation speed threshold; (“The electrical motor, which is an example of the electrical generator, may generate a torque (e.g., via a magnetic field) opposite to the rotation of the motor rotor, which results in a torque opposite to the rotational direction of the propulsor. For example, during normal operation where the electrical motor is generating electrical power, the motor rotor rotates in a first direction along with the propulsor; however, during hoteling mode, the electrical motor applies torque in a second, opposite direction to the rotational direction of propulsor to cause rotation of the propulsor to slow. If the counter-torque is equal to the force from the propulsor, the propulsor stops moving.” [0033], “There are other ways to slow or stop the rotation of the propulsor using the electrical motor (e.g., implement electromagnetic braking). For example, a drive and generator control system may increase the electrical braking load or resistance applied to the electrical motor. The increase in resistance will increase the torque necessary to rotate the motor rotor of the electrical motor which effectively slows down the propulsor, and may stop rotation of the propulsor if the electrical braking load is great enough.” [0034], “Processor 52 may utilize the position of LP shaft 42 (or possibly the position of LP shaft 42 at different times) as an input into the position control laws algorithm and determine the current or voltage that power electronics 50 is to apply. For instance, if LP shaft 42 is rotating faster than the desired setpoint, processor 52 may determine that there should be an increase in the current or voltage that power electronics 50 outputs to increase the electromotive force that electrical motor 24 applies via motor rotor shaft 22.” [0067]), which shows controlling a magnitude of the braking force by controlling the current of the output power, and can be controlled when the rotation speed of the shaft is greater than a desired setpoint, or a speed threshold. While this teaches identifying the rotation speed of the shaft and not the propulsor, the shaft is operably connected to the propulsor and controls the rotational speed of the propulsor. Thus, it would have been obvious to a person of ordinary skill in the art to identify the rotational speed of the shaft, as a person with ordinary skill has good reason to pursue the known options within his or her technical grasp. In turn, because the product as claimed has the properties predicted by the prior art, it would have been obvious to make the system or product where the rotational speed of the shaft is identified.
With respect to claims 4 and 12, Munevar in combination with Harwood, as shown in the rejection above, discloses the limitations of claims 2 and 10. The combination of Munevar and Harwood teaches an aircraft propulsion system of claims 2 and 10. Munevar further teaches:
wherein the instructions, when executed by the processor, cause the processor to increase the magnitude of the braking force, in the hotel mode, by modulating one or both of the current or the voltage in response to identifying a rotation speed of the rotational assembly greater than a rotation speed threshold; (“The electrical motor, which is an example of the electrical generator, may generate a torque (e.g., via a magnetic field) opposite to the rotation of the motor rotor, which results in a torque opposite to the rotational direction of the propulsor. For example, during normal operation where the electrical motor is generating electrical power, the motor rotor rotates in a first direction along with the propulsor; however, during hoteling mode, the electrical motor applies torque in a second, opposite direction to the rotational direction of propulsor to cause rotation of the propulsor to slow. If the counter-torque is equal to the force from the propulsor, the propulsor stops moving.” [0033], “There are other ways to slow or stop the rotation of the propulsor using the electrical motor (e.g., implement electromagnetic braking). For example, a drive and generator control system may increase the electrical braking load or resistance applied to the electrical motor. The increase in resistance will increase the torque necessary to rotate the motor rotor of the electrical motor which effectively slows down the propulsor, and may stop rotation of the propulsor if the electrical braking load is great enough.” [0034], “Processor 52 may utilize the position of LP shaft 42 (or possibly the position of LP shaft 42 at different times) as an input into the position control laws algorithm and determine the current or voltage that power electronics 50 is to apply. For instance, if LP shaft 42 is rotating faster than the desired setpoint, processor 52 may determine that there should be an increase in the current or voltage that power electronics 50 outputs to increase the electromotive force that electrical motor 24 applies via motor rotor shaft 22.” [0067]), which shows controlling a magnitude of the braking force by controlling the current of the output power, and can be controlled when the rotation speed of the shaft is greater than a desired setpoint, or a speed threshold.
With respect to claims 5 and 13, Munevar in combination with Harwood, as shown in the rejection above, discloses the limitations of claims 1 and 9. The combination of Munevar and Harwood teaches an aircraft propulsion system of claims 1 and 9. Munevar further teaches:
wherein the gas turbine engine further includes a second rotational assembly including a bladed compressor rotor, a bladed turbine rotor, and a second shaft, the second shaft interconnecting the bladed compressor rotor and the bladed turbine rotor, wherein the electrical assembly further includes a generator coupled with the second rotational assembly, the generator electrically connected to the electrical distribution system; (“In a gas turbine engine, the propulsor is coupled to a shaft (e.g., a low pressure shaft, as described below) such that the rotation of the shaft causes the propulsor to rotate. In this disclosure, the example techniques may stop or slow down the rotation of the shaft, and the shaft is coupled to propulsor meaning that stopping or slowing down the shaft stops or slows down the rotation of the propulsor.” [0019], “For example, the electrical generator includes a motor rotor, where the motor rotor includes a shaft. The motor rotor may be mechanically coupled to gear trains, for example through splined shafts, or may be electromechanically coupled to the drive shaft (e.g., low pressure shaft) of respective engines 14. In some examples, the engine drive shafts, such as a low pressure shaft or a high pressure shaft, may include integrated electrical generators (e.g., in which the rotor of the electrical generator is integrated in the low pressure shaft or high pressure shaft).” [0031]), and FIG. 2, which shows a gas turbine engine including a first and a second rotational assembly.
With respect to claim 7, Munevar in combination with Harwood, as shown in the rejection above, discloses the limitations of claim 1. The combination of Munevar and Harwood teaches an aircraft propulsion system of claim 1. Munevar further teaches:
wherein the AC electric motor includes a rotor, and the rotor is directly connected to the shaft; (“Motor rotor shaft 22 is the shaft of the motor rotor internal to electrical motor 24. The rotation of motor rotor shaft 22 causes electrical motor 24 to generate electrical power (e.g., voltage and current).” [0040]).
With respect to claim 8, Munevar in combination with Harwood, as shown in the rejection above, discloses the limitations of claim 1. The combination of Munevar and Harwood teaches an aircraft propulsion system of claim 1. Munevar further teaches:
wherein the AC electric motor includes a rotor, the gas turbine engine includes a reduction gear box, and the reduction gear box couples the rotational assembly and the rotor to the propulsor; (“controller may increase the resistance on the output of the electrical generator, which increases the torque needed to rotate a motor rotor of the electrical motor, which in turn reduces the speed or stops the propeller, rotor, or fan” [0014], “Turbine engine system 16 includes gearbox 20, and electrical motor 24 includes a motor rotor having motor rotor shaft 22 coupled to propulsor 18 via gearbox 20 (e.g., mechanically coupled via one or more gears within gearbox 20 or an electromagnetic gearbox). In the first operation mode, the rotation of propulsor 18 causes motor rotor shaft 22 to rotate in a first direction, and rotation of motor rotor shaft 22 causes the electrical motor to generate electrical power. In the second operation mode, in some examples, electrical motor 24 produces a counter torque on motor rotor shaft 22, which effectively torques propulsor 18 in a second direction opposite to the first direction to slow or stop the rotation of propulsor 18.” [0061]), where the motor includes a gear box, which can be used to reduce the rotational speed of the propulsor.
Claim(s) 15-18 and 20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Munevar (US 20170260872 A1) in view of Harwood et al. (US 11542021 B2), which was provided in the IDS sent on June 14, 2024, and Osama et al. (US 20220003128 A1).
Regarding claims 15-18 and 20:
With respect to claim 15, Munevar teaches:
a propulsor; (“Vehicles such as aircraft have different modes of operation. In a first mode (also called normal mode), a propulsor (e.g., a propeller, rotor, or fan) of a gas turbine engine rotates and provides the necessary thrust to move the vehicle.” [0015])
a gas turbine engine including a first rotational assembly and a second rotational assembly, the first rotational assembly and the second rotational assembly configured for rotation about a rotational axis of the gas turbine engine, (“For example, the electrical generator includes a motor rotor, where the motor rotor includes a shaft. The motor rotor may be mechanically coupled to gear trains, for example through splined shafts, or may be electromechanically coupled to the drive shaft (e.g., low pressure shaft) of respective engines 14. In some examples, the engine drive shafts, such as a low pressure shaft or a high pressure shaft, may include integrated electrical generators (e.g., in which the rotor of the electrical generator is integrated in the low pressure shaft or high pressure shaft).” [0031]), and FIG. 2, which shows a gas turbine engine including a first and a second rotational assembly.
the first rotational assembly including a bladed compressor rotor, a bladed turbine rotor, and a first shaft interconnecting the bladed compressor rotor and the bladed turbine rotor, (“For example, the electrical generator includes a motor rotor, where the motor rotor includes a shaft. The motor rotor may be mechanically coupled to gear trains, for example through splined shafts, or may be electromechanically coupled to the drive shaft (e.g., low pressure shaft) of respective engines 14. In some examples, the engine drive shafts, such as a low pressure shaft or a high pressure shaft, may include integrated electrical generators (e.g., in which the rotor of the electrical generator is integrated in the low pressure shaft or high pressure shaft).” [0031]), and FIG. 2, which shows a gas turbine engine including a first rotational assembly.
the second rotational assembly including a bladed power turbine rotor and a second shaft, the second shaft operably connecting the bladed power turbine rotor and the propulsor; (“In a gas turbine engine, the propulsor is coupled to a shaft (e.g., a low pressure shaft, as described below) such that the rotation of the shaft causes the propulsor to rotate. In this disclosure, the example techniques may stop or slow down the rotation of the shaft, and the shaft is coupled to propulsor meaning that stopping or slowing down the shaft stops or slows down the rotation of the propulsor.” [0019]), showing that the propulsor is controlled with a second rotational assembly, and FIG. 2, which shows a gas turbine engine including a second rotational assembly that is operably connected to the bladed turbine rotor and the propulsor.
an electrical assembly including an alternating current (AC) electric motor, a motor control unit, and an electrical distribution system, the AC electric motor including a rotor directly coupled to the second shaft, the motor control unit electrically connected to the AC electric motor and the electrical distribution system, the motor control unit including a processor connected in signal communication with non-transitory memory containing instructions, (“using an electronic brake that is implemented with a generator (e.g., electrical motor) and drive and generator control system (e.g., unit that controls the power electronics) to provide electromotive forces needed for the generator to slow down or stop the rotation of the propulsor. Because the motor rotor of the electrical motor is stopped or slowed down, the electrical motor may not generate any additional power.” [0021], “During a first mode of operation, such as normal operation where the engine is causing a device to move, the rotation of the propeller, rotor, or fan provides the electrical generator with the mechanical power to generate electrical power. During a second mode of operation, such as hoteling mode where reduced thrust is desired, the electrical generator may function as an electrical motor and apply a torque in opposite direction of rotation of the propeller, rotor, or fan, which reduces the rotation speed or stops the propeller, rotor, or fan. In some examples, a controller may increase the resistance on the output of the electrical generator, which increases the torque needed to rotate a motor rotor of the electrical motor, which in turn reduces the speed or stops the propeller, rotor, or fan.” [0014], “The output of power electronics 50 is a voltage or current to electrical motor 24 that causes electrical motor 24 to generate the counter-torque on motor rotor shaft 22 to stop or slow down the rotation of propulsor 18. Processor 52 determines the voltage or current level of the voltage or current that power electronics 50 is to provide electrical motor 24. Examples of processor 52 include one or more microprocessors, application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), digital signal processors (DSPs), or other equivalent integrated or discrete logic circuitry.” [0065]), where there is an electrical assembly that includes an electric motor, a motor control unit, and an electrical distribution system, and the motor is coupled to a rotational assembly. This also shows that the motor is operable in a normal mode and a hoteling mode.
While Munevar teaches an electric motor, it does not specify if it is an AC electric motor. However, Harwood teaches (“According to a first aspect there is provided a vehicle propulsion system comprising: at least first and second electrical generators, each being configured to provide AC electrical power to a respective first and second AC electrical network; at least first and second AC electrical motors directly electrically coupled to a respective AC network and coupled to a respective propulsor” (col 1, lines 43-50)), where the electrical generator provides AC electrical power. Harwood further teaches (“The shaft 13 of each gas turbine engine 6 is also coupled to a respective rotor (not shown) of first and second synchronous alternating current (AC) electrical generators 15a, 15b.” (col 3, lines 47-50), “the gas turbine engine 6 could comprise multiple shafts interconnecting different compressors and turbines, and the generators 15a, 15b could be driven by different gas turbine engine shafts, and so be rotated at different speeds.” (col 4, lines 9-12), which the electric motor is coupled can be coupled to a second shaft.
apply a braking force to the second rotational assembly by controlling the motor control unit to convert electrical power from the electrical distribution system to output DC electrical power and supplying the output DC electrical power to the AC electric motor; (“using an electronic brake that is implemented with a generator (e.g., electrical motor) and drive and generator control system (e.g., unit that controls the power electronics) to provide electromotive forces needed for the generator to slow down or stop the rotation of the propulsor. Because the motor rotor of the electrical motor is stopped or slowed down, the electrical motor may not generate any additional power.” [0021], “During a second mode of operation, such as hoteling mode where reduced thrust is desired, the electrical generator may function as an electrical motor and apply a torque in opposite direction of rotation of the propeller, rotor, or fan, which reduces the rotation speed or stops the propeller, rotor, or fan. In some examples, a controller may increase the resistance on the output of the electrical generator, which increases the torque needed to rotate a motor rotor of the electrical motor, which in turn reduces the speed or stops the propeller, rotor, or fan.” [0014]), where the rotational assembly is used to brake the propulsor.
While Munevar teaches an electric motor, it does not teach supplying output DC electrical power to the AC electric motor. However, Harwood teaches (“The first and/or second AC to DC converters may comprise bi-directional AC to DC converters configured to provide AC electrical power from the AC network to DC electrical power to the DC network, and DC electrical power from the DC network to AC electrical power to the AC electrical network.” (col 2, lines 6-11)), where DC electrical power can be supplied to the AC electrical network.
It would have been obvious to one of ordinary skill in the art before the effective filling date of the instant application to have combined Munevar’s propulsion system with Harwood’s AC and DC electrical systems because (“Advantageously, the first and second directly electrically coupled motors efficiently provide propulsive thrust in view of the low losses provided by wholly AC electrical systems, while thrust control can be provided utilising the one or more electrical motors coupled to the DC electrical network, without requiring either power electronics or control of the frequency of the AC networks. Consequently, the invention provides an efficient yet controllable aircraft propulsion system.” (col 1, lines 56-64)).
Munevar and Harwood do not teach, but Osama teaches:
wherein the bladed power turbine rotor is arranged between the rotor of the AC electric motor and the bladed turbine rotor; (“the turbine 104 includes a plurality of turbine rotor blades spaced along the axial direction A. More specifically, for the exemplary embodiment depicted, the turbine 104 includes a first plurality of turbine rotor blades 106 and a second plurality of turbine rotor blades 108” [0041], FIG. 2), which shows a turbine rotor positioned between a second turbine rotor and an electric motor.
It would have been obvious to one of ordinary skill in the art before the effective filling date of the instant application to have combined Munevar’s propulsion system with Osama’s aircraft propulsion system because (“General gas turbine engine design criteria often include conflicting criteria that must be balanced or compromised, including increasing fuel efficiency, operational efficiency, and/or power output while maintaining or reducing weight, part count, and/or packaging” see Osama [0005], “it may be beneficial to include electric generators operable with the engine to extract energy and provide such energy to various other systems of the aircraft including the propulsion system” see Osama [0004]).
With respect to claim 16, Munevar in combination with Harwood and Osama, as shown in the rejection above, discloses the limitations of claim 15. The combination of Munevar, Harwood, and Osama teaches an aircraft propulsion system of claim 15. Munevar further teaches:
wherein the instructions, when executed by the processor, cause the processor to control a magnitude of the braking force, in the hotel mode, by modulating one or both of a current or a voltage of the output DC electrical power; (“The output of power electronics 50 is a voltage or current to electrical motor 24 that causes electrical motor 24 to generate the counter-torque on motor rotor shaft 22 to stop or slow down the rotation of propulsor 18. Processor 52 determines the voltage or current level of the voltage or current that power electronics 50 is to provide electrical motor 24.” [0065], “Processor 52 may utilize the position of LP shaft 42 (or possibly the position of LP shaft 42 at different times) as an input into the position control laws algorithm and determine the current or voltage that power electronics 50 is to apply. For instance, if LP shaft 42 is rotating faster than the desired setpoint, processor 52 may determine that there should be an increase in the current or voltage that power electronics 50 outputs to increase the electromotive force that electrical motor 24 applies via motor rotor shaft 22.” [0067]), which shows controlling a magnitude of the braking force by controlling the current of the output power.
While Munevar teaches an electric motor, it does not teach supplying output DC electrical power to the AC electric motor. However, Harwood teaches (“The first and/or second AC to DC converters may comprise bi-directional AC to DC converters configured to provide AC electrical power from the AC network to DC electrical power to the DC network, and DC electrical power from the DC network to AC electrical power to the AC electrical network.” (col 2, lines 6-11)), where DC electrical power can be supplied to the AC electrical network.
It would have been obvious to one of ordinary skill in the art before the effective filling date of the instant application to have combined Munevar’s propulsion system with Harwood’s AC and DC electrical systems because (“Advantageously, the first and second directly electrically coupled motors efficiently provide propulsive thrust in view of the low losses provided by wholly AC electrical systems, while thrust control can be provided utilising the one or more electrical motors coupled to the DC electrical network, without requiring either power electronics or control of the frequency of the AC networks. Consequently, the invention provides an efficient yet controllable aircraft propulsion system.” (col 1, lines 56-64)).
With respect to claim 17, Munevar in combination with Harwood and Osama, as shown in the rejection above, discloses the limitations of claim 16. The combination of Munevar, Harwood, and Osama teaches an aircraft propulsion system of claim 16. Munevar further teaches:
wherein the instructions, when executed by the processor, cause the processor to increase the magnitude of the braking force, in the hotel mode, by modulating one or both of the current or the voltage in response to identifying a rotation speed of the propulsor greater than a rotation speed threshold; (“The electrical motor, which is an example of the electrical generator, may generate a torque (e.g., via a magnetic field) opposite to the rotation of the motor rotor, which results in a torque opposite to the rotational direction of the propulsor. For example, during normal operation where the electrical motor is generating electrical power, the motor rotor rotates in a first direction along with the propulsor; however, during hoteling mode, the electrical motor applies torque in a second, opposite direction to the rotational direction of propulsor to cause rotation of the propulsor to slow. If the counter-torque is equal to the force from the propulsor, the propulsor stops moving.” [0033], “There are other ways to slow or stop the rotation of the propulsor using the electrical motor (e.g., implement electromagnetic braking). For example, a drive and generator control system may increase the electrical braking load or resistance applied to the electrical motor. The increase in resistance will increase the torque necessary to rotate the motor rotor of the electrical motor which effectively slows down the propulsor, and may stop rotation of the propulsor if the electrical braking load is great enough.” [0034], “Processor 52 may utilize the position of LP shaft 42 (or possibly the position of LP shaft 42 at different times) as an input into the position control laws algorithm and determine the current or voltage that power electronics 50 is to apply. For instance, if LP shaft 42 is rotating faster than the desired setpoint, processor 52 may determine that there should be an increase in the current or voltage that power electronics 50 outputs to increase the electromotive force that electrical motor 24 applies via motor rotor shaft 22.” [0067]), which shows controlling a magnitude of the braking force by controlling the current of the output power, and can be controlled when the rotation speed of the shaft is greater than a desired setpoint, or a speed threshold. While this teaches identifying the rotation speed of the shaft and not the propulsor, the shaft is operably connected to the propulsor and controls the rotational speed of the propulsor. Thus, it would have been obvious to a person of ordinary skill in the art to identify the rotational speed of the shaft, as a person with ordinary skill has good reason to pursue the known options within his or her technical grasp. In turn, because the product as claimed has the properties predicted by the prior art, it would have been obvious to make the system or product where the rotational speed of the shaft is identified.
With respect to claim 18, Munevar in combination with Harwood and Osama, as shown in the rejection above, discloses the limitations of claim 16. The combination of Munevar, Harwood, and Osama teaches an aircraft propulsion system of claim 16. Munevar further teaches:
wherein the instructions, when executed by the processor, cause the processor to increase the magnitude of the braking force by modulating one or both of the current or the voltage in response to identifying a rotation speed of the rotational assembly greater than a rotation speed threshold; (“The electrical motor, which is an example of the electrical generator, may generate a torque (e.g., via a magnetic field) opposite to the rotation of the motor rotor, which results in a torque opposite to the rotational direction of the propulsor. For example, during normal operation where the electrical motor is generating electrical power, the motor rotor rotates in a first direction along with the propulsor; however, during hoteling mode, the electrical motor applies torque in a second, opposite direction to the rotational direction of propulsor to cause rotation of the propulsor to slow. If the counter-torque is equal to the force from the propulsor, the propulsor stops moving.” [0033], “There are other ways to slow or stop the rotation of the propulsor using the electrical motor (e.g., implement electromagnetic braking). For example, a drive and generator control system may increase the electrical braking load or resistance applied to the electrical motor. The increase in resistance will increase the torque necessary to rotate the motor rotor of the electrical motor which effectively slows down the propulsor, and may stop rotation of the propulsor if the electrical braking load is great enough.” [0034], “Processor 52 may utilize the position of LP shaft 42 (or possibly the position of LP shaft 42 at different times) as an input into the position control laws algorithm and determine the current or voltage that power electronics 50 is to apply. For instance, if LP shaft 42 is rotating faster than the desired setpoint, processor 52 may determine that there should be an increase in the current or voltage that power electronics 50 outputs to increase the electromotive force that electrical motor 24 applies via motor rotor shaft 22.” [0067]), which shows controlling a magnitude of the braking force by controlling the current of the output power, and can be controlled when the rotation speed of the shaft is greater than a desired setpoint, or a speed threshold.
With respect to claim 20, Munevar in combination with Harwood and Osama, as shown in the rejection above, discloses the limitations of claim 15. The combination of Munevar, Harwood, and Osama teaches an aircraft propulsion system of claim 15. Munevar further teaches:
wherein the AC electric motor includes a rotor, the gas turbine engine includes a reduction gear box, and the reduction gear box couples the rotational assembly and the rotor to the propulsor; (“controller may increase the resistance on the output of the electrical generator, which increases the torque needed to rotate a motor rotor of the electrical motor, which in turn reduces the speed or stops the propeller, rotor, or fan” [0014], “Turbine engine system 16 includes gearbox 20, and electrical motor 24 includes a motor rotor having motor rotor shaft 22 coupled to propulsor 18 via gearbox 20 (e.g., mechanically coupled via one or more gears within gearbox 20 or an electromagnetic gearbox). In the first operation mode, the rotation of propulsor 18 causes motor rotor shaft 22 to rotate in a first direction, and rotation of motor rotor shaft 22 causes the electrical motor to generate electrical power. In the second operation mode, in some examples, electrical motor 24 produces a counter torque on motor rotor shaft 22, which effectively torques propulsor 18 in a second direction opposite to the first direction to slow or stop the rotation of propulsor 18.” [0061]), where the motor includes a gear box, which can be used to reduce the rotational speed of the propulsor.
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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/CHRISTINE NGUYEN HUYNH/Examiner, Art Unit 3662
/ANISS CHAD/Supervisory Patent Examiner, Art Unit 3662
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