DETAILED ACTION
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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 2/11/2026 has been entered.
Notice to Applicant
Claims 1-3, 5-8, 15-16, and 18-20 have been examined in this application. This communication is a non-final rejection in response to the “Amendments to the claims” and “Remarks” filed 2/11/2026.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claims 1-3, 5-8, 15, 17, and 20 are rejected under 35 USC 103 as being obvious over US Patent Number 2,462,201 to Kilgore in view of US Patent Application Number 2013/0181562 by Gieras and US Patent Application Number 2020/0216183 by Veilleux.
Regarding claim 1, Kilgore discloses an aircraft system, comprising:
An aircraft fuselage including a forward end and an aft end (fuselage 2);
An aircraft wing projecting out from the aircraft fuselage (wings 3);
A first propulsion unit mounted to the aircraft wing (electric motor drive for inner propeller 20 on one of the wings 3 in Figure 1, in details for the motor drive in Figure 3), the first propulsion unit comprising a first propulsor rotor (propeller 20) and an electric machine (electric motor-drive for propeller 20 shown in Figure 3);
A second propulsion unit mounted to the aircraft wing and discrete from the first propulsion unit (outer propeller 20 on the same wing 3 in Figure 1), the second propulsion unit comprising a second electric machine (Figure 3 shows the electric motor drive for each propeller 20);
The first propulsor rotor rotatable about an axis (around shaft 21);
A power source electrically coupled to the electric machine and the second electric machine (power-plant 4), the power source comprising one or more power storage devices (column 12, lines 40-46 disclose “Our electrical drive-system, therefore, is particularly well adapted for the use of gasoline-powered turbines 47, or other turbines utilizing some other medium equivalent to gasoline in the sense of a means for storing energy in large quantities, and using it as desired and required”) and one or more electrical generators (electrical generators 5), the power source configured to power the first motor and the second motor (column 9, lines 62-65 disclose “the four propeller-driving motors 22 are all energized, through individual switches 25, from the three-phase motor-bus 17”, and Figures 1-3 show motor-bus 17 connected to generators 5 through bus 16 and switch 15), the power source housed within the aircraft fuselage (see Figure 1), and the power source configured to power the first propulsion unit and the second propulsion unit (claim 1 discloses “A power plant for driving a plurality of rotating propulsion-propellers for producing a propelling force in air”);
An gas turbine engine (column 12, lines 31-33 disclose “it is possible, however, to utilize a gas or steam turbine 47 for the prime-mover”) configured to power the electric machine through the power source (Kilgore discusses generators 5 powering the electric motor-drives for propellers 20, and column 12, lines 31-35 discloses substituting gas or steam turbines 47 for generators 5), the engine housed within the aircraft fuselage (see Figure 5).
Kilgore does not disclose the first propulsion unit comprising a first propulsor rotor, a second propulsor rotor and an electric machine, the second propulsion unit comprising a second electric machine, the second propulsor rotor rotatable about the axis, the electric machine including a first electric machine rotor, a second electric machine rotor and an electric machine stator radially between the first electric machine rotor and the second electric machine rotor, the first electric machine rotor rotatable about the axis and rotatably connected to the first propulsor rotor, and the first electric machine rotor and the electric machine stator forming a first motor configured to drive rotation of the first propulsor rotor, and the second electric machine rotor rotatable about the axis and rotatably connected to the second propulsor rotor, and the second electric machine rotor and the electric machine stator forming a second motor configured to drive rotation of the second propulsor rotor, the propulsion unit including the first propulsor rotor, the second propulsor rotor and the electric machine. However, these limitations are taught by Gieras. Gieras discloses an electric machine comprising a first electric machine rotor (rotor 40), a second electric machine rotor (rotor 30) and an electric machine stator (stator 20) radially between the first electric machine rotor and the second electric machine rotor (see Figure 3), the first electric machine rotor rotatable about the axis and rotatably connected to the first propulsor rotor (through shaft 46), and the first electric machine rotor and the electric machine stator forming a first motor configured to drive rotation of the first propulsor rotor (paragraph 29 discloses “The excitation element 24 of the stator 20 generates magnetic fields to drive the first shaft 38 in a first direction and the second shaft 46 in the opposite direction. In this manner, the blades 72 and 74 of the contra-rotating propellers are driven in opposing directions”), the second electric machine rotor rotatable about the axis and rotatably connected to the second propulsor rotor (through shaft 38), and the second electric machine rotor and the electric machine stator forming a second motor configured to drive rotation of the second propulsor rotor (see paragraph 29), and a propulsion unit (12) including a first propulsor rotor &72), a second propulsor rotor (74) and the electric machine (see Figure 3). It would be obvious to a person having ordinary skill in the art to modify Kilgore using the teachings from Gieras in order to use known types of electric machines for driving propellers in order to power the propellers of the aircraft and to power additional propellers for additional propulsion.
Kilgore does not disclose the power source housed within the aircraft fuselage at the aft end. However, this limitation is taught by Veilleux. Veilleux discloses an aircraft with a gas turbine engine 16 and a power source (power bus 24), and Figure 3 shows the power bus being housed within the aft end of the fuselage. It would be obvious to a person having ordinary skill in the art to modify Kilgore using the teachings from Veilleux in order to rearrange the components of the aircraft to provide functional space and weight balancing as needed.
Regarding claim 2 (dependent on claim 1), Gieras further teaches the first motor is configured to drive rotation of the first propulsor rotor in a first direction about the axis, and the second motor is configured to drive rotation of the second propulsor rotor in a second direction about the axis that is opposite the first direction. Paragraph 29 discloses “The excitation element 24 of the stator 20 generates magnetic fields to drive the first shaft 38 in a first direction and the second shaft 46 in the opposite direction. In this manner, the blades 72 and 74 of the contra-rotating propellers are driven in opposing directions”.
Regarding claim 3 (dependent on claim 1), Gieras further teaches the first motor is configured to drive rotation of the first propulsor rotor in a first direction about the axis, and the second motor is configured to drive rotation of the second propulsor rotor in the first direction about the axis. Paragraph 23 discloses “In an alternative embodiment, the first and second rotors 30 and 40 rotate in the same direction”.
Regarding claim 5 (dependent on claim 1)¸ Gieras further teaches the second propulsor rotor (blade 74) being arranged axially between the first propulsion rotor (blade 72) and the electric machine (machine 12, see Figure 3).
Regarding claim 6 (dependent on claim 1)¸ Gieras further teaches the second propulsor rotor (blade 74) being arranged axially between the first propulsion rotor (blade 72) and the first motor (rotor 40, see Figure 3).
Regarding claim 7 (dependent on claim 1)¸ Gieras further teaches the electric machine stator (stator 20) extending axially along the first electric machine rotor (rotor 40) and the second electric machine rotor (rotor 30, see Figure 3).
Regarding claim 8 (dependent on claim 1), Gieras further teaches the second electric machine rotor axially overlaps the first electric machine rotor (see rotors 30 and 40 in Figure 3).
Regarding claim 15 (dependent on claim 1), Gieras further teaches at least one of the first propulsor rotor is a first un-ducted rotor, and the second propulsor rotor is a second un-ducted rotor (see Figure 3).
Regarding claim 20, Kilgore discloses an aircraft system, comprising:
A fuselage (fuselage 2);
A wing connected to and projecting out from the fuselage (wings 3);
A plurality of propulsion units mounted to the wing (electric motor drive for inner propellers 20);
A power source electrically coupled to each of the plurality of propulsion units (power plant 4), the power source comprising one or more power storage devices (column 12, lines 40-46 disclose “Our electrical drive-system, therefore, is particularly well adapted for the use of gasoline-powered turbines 47, or other turbines utilizing some other medium equivalent to gasoline in the sense of a means for storing energy in large quantities, and using it as desired and required”) and one or more electrical generators (electrical generators 5).
Kilgore does not disclose each of the plurality of propulsion units including a first propulsor rotor rotatable about an axis, a second propulsor rotor rotatable about the axis, a first motor coupled to and configured to drive rotation of the first propulsor rotor, and a second motor coupled to and configured to drive rotation of the second propulsor rotor, and the power source mounted to the wing. However, these limitations are taught by Gieras. Gieras discloses a propulsion unit 12 including a first propulsor rotor 72 rotatable about an axis A, a second propulsor rotor 72 rotatable about the axis A, a first motor 40 coupled to and configured to drive rotation of the first propulsor rotor (through shaft 46), and a second motor (30) coupled to and configured to drive rotation of the second propulsor rotor (30).
Reyes and Gieras do not disclose the power source being mounted to the wing and disposed between a first of the plurality of propulsion units and a second of the plurality of propulsion units, and the power source spaced from the first of the plurality of propulsion units and the second of the plurality of propulsion units spanwise along the wing. However, it would have been obvious to one having ordinary skill in the art at the time the invention was made to place the power source wherever desired on the aircraft in order to provide power to the propulsion units while maintaining weight balance on the aircraft, since it has been held that rearranging parts of an invention involves only routine skill in the art. In re Japikse, 86 USPQ 70.
Claim 16 is rejected under 35 USC 103 as being obvious over US Patent Number 2,462,201 to Kilgore in view of US Patent Application Number 2013/0181562 by Gieras and US Patent Application Number 2020/0216183 by Veilleux, in further view of US Patent Number 8,464,511 to Ribarov
Regarding claim 16 (dependent on claim 1), Kilgore and Gieras do not disclose at least one of the first propulsor rotor being a first ducted rotor and the second propulsor rotor being a second ducted rotor. However, this limitation is taught by Ribarov. Column 2, lines 46-48 disclose “propulsion rotors 12 and 14 have both ducted and unducted (free) rotor blade configurations”. It would be obvious to a person having ordinary skill in the art to modify Kilgore and Gieras using the teachings from Ribarov to use known types of rotors for aircraft engines.
Claims 18-19 are rejected under 35 USC 103 as being obvious over US Patent Number 2,462,201 to Kilgore in view of US Patent Application Number 2013/0181562 by Gieras and US Patent Application Number 2020/0216183 by Veilleux, in further view of US Patent Number 1,874,523 to Henrichsen.
Regarding claim 18, Kilgore discloses an aircraft system, comprising:
A propulsion unit including a first propulsor rotor (propeller 20), a first motor (motor 22), a drivetrain system (gear structure 23) and an electric machine (electric motor-drive for propeller 20 shown in Figure 3),
The first propulsor rotor rotatable about an axis (shaft 21), the first propulsor rotor disposed on a downstream end of the propulsion unit (see Figures 1 and 3);
A power source discrete from the propulsion unit (power-plant 4), the power source being electrically coupled to and configured to electrically power the first motor and the second motor (claim 1 discloses “A power plant for driving a plurality of rotating propulsion-propellers for producing a propelling force in air”), the power source including one or more power storage devices (column 12, lines 40-46 disclose “Our electrical drive-system, therefore, is particularly well adapted for the use of gasoline-powered turbines 47, or other turbines utilizing some other medium equivalent to gasoline in the sense of a means for storing energy in large quantities, and using it as desired and required”).
Kilgore does not disclose the propulsion unit including a second propulsor rotor and a second motor, the electric machine including a first rotor, a second rotor and a stator, the stator radially between the first rotor and the second rotor; a first motor including the first rotor and the stator, the second rotor circumscribing and extending axially along the first rotor, and the first motor configured to drive rotation of the first propulsor rotor, a second motor including the second rotor and the stator, and the second motor configured to drive rotation of the second propulsor rotor, the drivetrain system including a first drivetrain and a second drivetrain, the first drivetrain configured to operatively connect the first motor to the first propulsor rotor, and the second drivetrain configured to operatively connect the second motor to the second propulsor rotor, the power source being electrically coupled to and configured to electrically power the first motor and the second motor, the power source including one or more power storage devices. However, these limitations are taught by Gieras. Gieras discloses a propulsion unit including a first propulsor rotor (blade 72) and a second propulsor rotor (blade 74) rotatable about the same axis (Axis A) two motors (see Figure 3), the first motor including a first rotor (rotor 40) and a stator (stator 20) that circumscribes and extends axially along the first rotor (see Figure 3), and the first motor configured to drive rotation of the first propulsor rotor through a first powertrain (shaft 46), and the second motor including the stator (stator 20) and a second rotor (rotor 30), the second rotor circumscribing and extending axially along the stator (see Figure 3), and the second motor configured to drive rotation of the second propulsor rotor through a second powertrain (shaft 38). It would be obvious to a person having ordinary skill in the art to modify Kilgore using the teachings from Gieras in order to use known types of electric machines for driving propellers in order to power the propellers of the aircraft and to power additional propellers for additional propulsion.
Kilgore and Gieras do not disclose the second propulsor rotor disposed on an upstream end of the propulsion unit. However, this limitation is taught by Henrichsen. Henrichsen discloses a propulsion unit having a first propulsor rotor 12 disposed on an upstream end of the propulsion unit and a second propulsor rotor 14 disposed on a downstream end of the propulsion unit. It would be obvious to a person having ordinary skill in the art to modify Kilgore and Gieras using the teachings from Henrichsen in order to space apart the rotors and to provide both pushing and pulling forces to provide additional propulsion to the unit.
Regarding claim 19 (dependent on claim 18)¸ Kilgore discloses a thermal engine configured to power the first motor and the second motor through the power source (internal combustion engine 12). Column 12, lines 31-33 disclose “it is possible, however, to utilize a gas or steam turbine 47 for the prime-mover”.
Response to Arguments
Applicant's arguments filed 2/11/2026 have been fully considered but they are not persuasive.
Applicant’s arguments regarding the power source being housed at the aft end of the fuselage are moot in view of the current grounds of rejection.
Regarding the argument that modifying Kilgore to place the power source at the aft end would be in contrast to the teachings of Kilgore, the fact that Kilgore includes a centrally located electrical power plant does not teach away from moving the power plant to other parts of the aircraft as needed. Components are often moved around the aircraft in order to make space for passengers or payloads, and components furthermore need to be moved around in order to balance the weight on the aircraft for flight.
Regarding the argument that the office action has provided no context for the rearrangement of the power source as it relates to the proposed combination of Kilgore and Gieras, as discussed above, components are often moved around the aircraft in order to make space for passengers or payloads as needed and to balance the weight of the aircraft so that it remains stable during flight. Wings are often used as a possible location for components, as passengers and payloads are generally not stored in the wing. It is unclear what other context is needed for this rearrangement, as the proposed combination of Kilgore and Gieras moves around components of the aircraft in well-known ways.
Regarding claim 18, the section of Kilgore that were quoted but not emphasized by the applicant clearly states that propellers 20 may be of either pusher or tractor type. Although the emphasized portions discuss the advantages of pusher type propellers, this does not teach away from the fact that Kilgore explicitly states that propellers may be of the tractor type, and furthermore does not discuss the benefits of tractor type propellers over pusher type propellers, such as the fact that tractor propellers operate in air that is undisturbed by the airfoil surface and therefore have better blade efficiency and thrust generation.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to MICHAEL H WANG whose telephone number is (571)272-6554. The examiner can normally be reached 10-6:30.
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MICHAEL H. WANG
Primary Examiner
Art Unit 3642
/MICHAEL H WANG/Primary Examiner, Art Unit 3642
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