DETAILED ACTION
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Note Regarding Claim Amendments
For future reference it is noted that deleted text should be represented in the claim amendments. For example, the phrase “generated by” in the claim set of 01/21/2025 was deleted from claim 1 (at line 10 and at line 14) and the deletion is not shown in the 03/19/2026 claim set. Thus for example lines 10-11 of the 03/19 claim set should have been shown as: “a first thrust contribution from an unducted airflow stream passing through the plurality”. Additionally, for example claim 17 line 12 should have been shown as “speed of the first unducted fan”.
Claim Objections
Claim 14 is objected to because of the following informalities:
claim 14 recites “a thrust split”, “an unducted airflow stream” and “a ducted airflow stream” in lines 2-3; it should be clarified whether the claim 14 instant recitations (1) refer to the claim 12 “thrust split”, “unducted airflow stream” and “ducted airflow stream”, or (2) are a different thrust split, unducted airflow stream and ducted airflow stream.
Appropriate correction is required.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claim 1-3 and 7-16 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 11 recites “an unducted airflow stream”. It is unclear if the claim 11 unducted airflow stream refers to (1) the claim 1 lines 10-11 “unducted airflow stream” or (2) is a different unducted airflow stream. For purposes of compact prosecution the claim is interpreted regarding the former.
Claims dependent thereon are rejected for the same reasons.
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.
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.
Claim(s) 1, 2 and 7-19 is/are rejected under 35 U.S.C. 103 as unpatentable over Pub. No. US 2021/0108595 A1 (Khalid) as evidenced by Pub. No. US 2023/0220815 A1 (Ostdiek), Pub. No. 2010/0119366 A1 (Bushnell) and US 20100251726 A1 (Jones).
Regarding claim 1, Khalid discloses (see fig. 1) an engine 10, comprising: an unducted fan 20 drivingly coupled (via shaft 5055) with a low-pressure turbine (5050; see at location 50 in fig. 1 and par. 45), the unducted fan 20 comprising a plurality of fan blades 21, wherein a pitch angle of the plurality of fan blades 21 is variable (see par. 56); a plurality of unducted outlet guide vanes 31, wherein a pitch angle of the plurality of unducted outlet guide vanes 31 is variable (see par. 56); and a controller (computing system 210; see pars. 144 and 217 pointing out that instant controller commands blade and vane pitch angles; and see par. 35 stating computing system 210 includes corresponding controllers 1600, 1610, 1700, 1800) configured to reduce a noise of the engine based on a noise sensitive condition (acoustic sensor provides input to controller; see par. 139, bottom, par. 140 and par. 141, top; in addition the controller receives rotor speed N1, see par. 126 middle, relating to the beat frequencies, see par. 162, middle; reduction of noise is also discussed at pars. 41, 42, 60 and 90) from a first noise value to a second noise value of the engine (vane 31 pitch angle is adjusted to reduce noise for example from a first value to a second value; for example discussion of acoustic noise communicates corresponding noise levels or values; see pars. 33 and 56; similar discussions are in pars. 75,89,90,94,103 and 106; also par. 162 discusses attenuating beat frequencies by way of increasing or decreasing “rotor assembly speed” referring to rotor assembly 20) by:
adjusting the pitch angle of the plurality of unducted outlet guide vanes (the pitch angle may be adjusted to a more open angle or a more closed angle in order to reduce noise, see par. 106; also see pars. 41-42) from a first pitch angle to a second pitch angle (adjusting the vane pitch angle involves changing the pitch angle from a first angle to a second angle; for example, see fig. 14 showing a first pitch angle, PITCH 1, and a second pitch angle, PITCH 2, of outlet guide vane 31, fig. 14 being described in pars. 17 and 103), wherein the second pitch angle is a relatively closed pitch angle with respect to the first pitch angle (because the pitch angle is adjusted to a more closed angle, then the second pitch angle would be more closed) such that a first thrust contribution (see par. 41: “The vane assembly 30 [comprising unducted outlet guide vanes 31] may generally define a de-swirler device configured to reduce or convert kinetic energy losses from unducted rotors into thrust output”) generated by the plurality of outlet guide vanes is reduced (closing the pitch angle correlates with rotating vane 31 in fig. 17 in the counter-clockwise (CCW) direction as pointed out in par. 111, top wherein this CCW rotation would decrease mass flow between adjacent vanes and thus reduce thrust because the flow from the fan is turned circumferentially; this is evidenced by Ostdiek pars. 96 and 99; in addition closing the vanes in the CCW direction is not consistent with removing the tangential component of the velocity from the upstream unducted fan, such removal done to increase thrust; therefore opening the outlet guide vanes would tend to increase thrust and thus closing the vanes would decrease thrust, as discussed in evidentiary reference Bushnell par. 24 and at Khalid par. 109);
adjusting a speed of the unducted fan 20 (see par. 162: the “engine including … increase[ing] … rotor assembly speed … to mitigate or attenuate beat interferences” wherein beat frequencies are a type of noise, see par. 156 stating “acoustic beat frequencies” and par. 163, top stating “undesired noise, such as beat frequency”; and wherein rotor assembly refers to the unducted fan 20 rotor, see par. 166, middle, having unducted fan blades 21, see fig. 1) from a first speed to a second speed (increasing the speed would regard increasing the speed from a first speed to a second speed), wherein the second speed is a relatively higher speed with respect to the first speed (the speed is increased as discussed above regarding par. 162) such that a second thrust contribution from the unducted fan is increased (Khalid can control thrust by rotor 20 speed, see par. 122; when thrust is controlled by rotor speed then one of ordinary skill in the art understands that an increase in rotor speed correlates with an increase in thrust, this is evidenced by Jones in par. 42: “The increased speed of low rotor 14 increases thrust” wherein low rotor 14 drives unducted fan 23 in Jones fig. 1) to maintain an overall thrust of the engine (par. 144 points out maintaining thrust by way of adjusting acoustics and beat frequencies; wherein the former is reduced as discussed above regarding pars. 106 and 41-42 regarding vane 31 pitch angle; and the latter is controlled by increasing speed regarding par. 162); wherein the controller is configured to adjust (see pars. 144 and 217) the pitch angle of the plurality of outlet guide vanes and adjust (see pars. 122 and 162) the speed of the unducted fan to reduce noise (the adjustment of vane angle and the adjustment of the speed are done to reduce noise as discussed above in this claim 1 analysis). Khalid does not disclose the increase in the second thrust contribution compensates for the reduction in the first thrust contribution; and the controller coordinates.
Khalid teaches the increase in the second thrust contribution compensates for the reduction in the first thrust contribution; and the controller coordinates (Khalid teaches in par. 161, bottom “mitigate or eliminate undesired noise while avoiding asymmetric thrust … conditions” in the context of controlling two engines regarding figs. 30-31; thus the controller would seek to maintain the thrust level of the first engine whose speed is being increased such that there is not asymmetric thrust between the first and second engines in fig. 31 for example).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the current invention to provide Khalid with the increase in the second thrust contribution compensates for the reduction in the first thrust contribution; and the controller coordinates as taught by Khalid in order to facilitate reducing pilot workload (asymmetric thrust conditions cause a yaw in the aircraft that has to be monitored and/or corrected by the pilot). This results in the controller coordinating the adjusting of the vane 31 pitch angle and the adjusting of the speed of the unducted fan 20 such that the changes in the respective first and second thrust contributions do not result in excessive asymmetric thrust.
Regarding claim 2, Khalid teaches the current invention as claimed and discussed above. Khalid teaches changing the pitch angle of the unducted outlet guide vanes 31 relative to a design point (a design point of Khalid can be an operating condition that takes place before the need to change the pitch angle occurs) based on the noise sensitive condition comprises closing the unducted outlet guide vanes as discussed in the claim 1 analysis above. Khalid does not explicitly disclose closing the vanes by 5 to 15 degrees relative to the design point.
Here, Khalid teaches in paragraphs 41 and 75 that the amount of change of the vane angle has an effect on acoustic noise, thrust angle and thrust magnitude. Therefore, an ordinary skilled worker would recognize that amount of closing of the vane controls factors such as noise and thrust that relate to fuel efficiency and the aircraft’s ability to operate in noise sensitive environments. Thus, the claimed wherein closing the vanes by 5 to 15 degrees relative to the design point is found to be an obvious optimization of the prior art obtainable by an ordinary skilled worker through routine experimentation.
Therefore, since the general conditions of the claim, i.e., changing or closing the vane angle, were disclosed in the prior art by Khalid, it is not inventive to discover the optimum workable range by routine experimentation, and it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Khalid’s invention to include wherein closing the vanes by 5 to 15 degrees relative to the design point in order to provide thrust performance and reduced noise as suggested and taught by Khalid in paragraphs 41 and 75. It has been held “where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation”, In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955).
Regarding claim 7, Khalid teaches the current invention as claimed and discussed above. Khalid teaches the noise sensitive condition is based on at least one of a location (see “regulated noise environments” in par. 68), an altitude (see par. 42 pointing out that cruise altitude is an altitude wherein noise mitigation is a concern), and a time of day.
Regarding claim 8, Khalid teaches the current invention as claimed and discussed above. Khalid teaches the noise sensitive condition is based on a noise measurement point of at least one of approach (see lower portion of par. 79), cutback, and sideline.
Regarding claim 9, Khalid teaches the current invention as claimed and discussed above. Khalid teaches the noise sensitive condition is based on a selected noise threshold. One of ordinary skill in the art understands that the endpoints of the ranges of noise levels in par. 33 can be considered thresholds.
Regarding claim 10, Khalid teaches the current invention as claimed and discussed above. Khalid teaches the noise sensitive condition is based on maintaining noise value at a noise level (see “desired acoustic noise level” in par. 41).
Regarding claim 11, Khalid teaches the current invention as claimed and discussed above. Khalid discussed thus far does not teach wherein the controller is further configured to adjust a thrust split between an unducted airflow stream and a ducted airflow stream. Khalid further teaches wherein the controller is further configured to adjust a thrust split (par. 131 points out for example that the controller can adjust both (1) the unducted variable outlet guide vanes 31 angle and unducted fan pitch angle thus adjusting the thrust of the unducted airstream, and (2) the mid-fan inlet guide vanes and third stream variable nozzle thus adjusting the thrust of the bypass airstream 1063 also termed “third” airstream at par. 46, top; Sargisson col. 5, ll. 3-8, 27-34 and 45-59 is evidence regarding the instant adjusting of the ducted airstream and resulting thrust split) between an unducted airflow stream (the airstream of unducted fan 20 comprising unducted fan blades 21; such unducted fan 20 creating thrust; see par. 53) and a ducted airflow stream (bypass airstream 1063 including the “mid-fan” discussed in par. 131, middle and also in par. 46 termed “fan stages”; one of ordinary skill in the art would understand the instant mid-fan to be within the airstream path 1062 upstream of bypass 1063; knowledge of one of ordinary skill regarding mid-fan is pointed out in the pertinent prior art infra; for example “mid” refers to middle region regarding axial length L in fig. 1).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the current invention to provide Khalid discussed thus far with wherein the controller is further configured to adjust a thrust split between an unducted airflow stream and a ducted airflow stream as taught by Khalid par. 131 in order to maintain a desired output thrust (see par. 131 top) and/or to adapt to different flight phases such as climb, cruise or approach for example (see par. 122, bottom; such paragraph points out that “adjusting thrust output based on … a flight condition (e.g. … climb, cruise, approach, … etc.” ). The thrust split is changed because (2) the thrust at bypass duct 1063 is increased by way of adjustment of the inlet guide vanes used to adjust the thrust of the ducted fan.
Regarding claim 12, Khalid teaches the current invention as claimed and discussed above. Khalid teaches adjusting the thrust split between the unducted airflow stream and the ducted airflow stream comprises maintaining a nominal thrust of the engine. Khalid discloses (see fig. 1) the controller configured to maintain a nominal thrust of an engine 10 (while reducing noise; 210; see pars 144 and 217 pointing out that instant controller reduces undesired noise while maintaining desired thrust levels; for example, controller “maintains” desired thrust when improving noise levels pointed out in par. 144; the term “nominal can be interpreted as “satisfactory”, Merriam-Webster online).
In further discussion, Khalid discloses maintaining the nominal thrust during adjusting of thrust splits. For example, the desired thrust is maintained during adjustment of variable geometry (VG) to adjust power (see pars. 129 and 131). More particularly a desired thrust is maintained for example relating to adjustment of compressor stator vanes and/or inlet guide vanes, see par. 131 top and middle). Such adjustments control the amount of air entering the flowpaths 1062,1063 (in fig. 1 of Khalid) and thus control the contribution of thrust of those respective airstreams and therefore affect the thrust split between unducted fan 20 stream and instant ducted streams.
Regarding claim 13, Khalid teaches the current invention as claimed and discussed above. Khalid teaches a ducted fan (mid-fan discussed in the claim 11 analysis above; this is consistent with “mid-fan” in applicant pars. 36 and 115) and inlet guide vanes (see par. 131 middle “a mid-fan inlet guide vane”; one of ordinary skill would understand this to be a set of vanes, this is evidenced by Sargisson col. 5, ll. 28-29 referring to inlet guide vanes 46 in fig. 2) forward of the ducted fan, wherein a pitch angle of the inlet guide vanes is variable (see “variable geometry” at par. 129, middle; this is evidenced by Sargisson col. 4, ll. 60-65).
Regarding claim 14, Khalid teaches the current invention as claimed and discussed above. Khalid teaches the controller is configured to control the pitch angle of the inlet guide vanes to adjust a thrust split between an unducted airflow stream and a ducted airflow stream (this is discussed in the claims 11-12 analysis above) is based on the noise sensitive condition (the control of the inlet guide vanes, see par. 131, middle, is based on “acoustic sensor”; see par. 131, bottom).
Regarding claim 15, Khalid teaches the current invention as claimed and discussed above. Khalid teaches a variable area fan duct nozzle (see par. 131 middle: “third-stream variable nozzle” wherein third stream refers to duct 1063, see par. 46 top “third-stream flowpath 1063”).
Regarding claim 16, Khalid teaches the current invention as claimed and discussed above. Khalid teaches the controller is configured to control the area of the variable area fan duct nozzle to adjust the thrust split (this is discussed in the claims 11-12 analysis above) between the unducted airflow stream and the ducted airflow stream based on the noise sensitive condition (the control of the variable area nozzle, see par. 131, middle, is based on “acoustic sensor”; see par. 131, bottom).
Regarding claim 17, Khalid discloses (see figs. 1 and 31) an aircraft (see par. 156. top), comprising: a first engine 10A comprising a first unducted fan 20, a first ducted fan (“mid-fan” discussed in par. 131, middle and also in par. 46 termed “fan stages”; one of ordinary skill in the art when reading the instant paragraphs would understand the instant mid-fan of fan stages to be a ducted fan within the airstream path 1062 upstream of bypass 1063); knowledge of one of ordinary skill regarding this topic is pointed out in the pertinent prior art infra), and first outlet guide vanes 31; a second engine 10B comprising a second unducted fan 20, a second ducted fan (“mid-fan” discussed in par. 131, middle and also in par. 46 termed “fan stages”; one of ordinary skill in the art would understand the instant mid-fan to be within the airstream path 1062 upstream of bypass 1063; knowledge of one of ordinary skill is pointed out in the pertinent prior art infra), and second outlet guide vanes 31; and a controller (controller 1900 or the combination of each FADEC controller 210 from the two instant engines; see pars. 157-158) configured to operate the first engine and the second engine (see pars. 157-158), the controller configured to reduce a noise (acoustic sensor provides input to controller; see par. 139, bottom, par. 140 and par. 141, top; reduction of noise is also discussed at pars. 41, 42, 60 and 90) of at least one of the first engine and the second engine from a first noise level to a second noise level (the noise levels of both engines are reduced or improved; noise levels in general are discussed at par. 33) by independently adjusting, based on a first noise value (frequency of first engine; see par. 156, bottom) associated with the first engine and a second noise value (frequency of second engine; see par. 156, bottom) associated with the second engine:
(a first embodiment of the controller includes:) adjusting one of a first pitch angle of the first outlet guide vanes and a first speed of the first unducted fan (unducted fan 20 speed is adjusted as a function of pitch angle in order to adjust acoustics; see par. 141, top) that results in a first thrust adjustment (the blade 21 pitch angle is a parameter “indicative of thrust output”, see par. 141, middle); and
adjusting the other of the first pitch angle of the first outlet guide vanes (par. 141, middle states two parameters may adjusted, the second being including vane pitch angle in addition to rotor assembly speed) and the first speed of the first unducted fan; and
adjusting one of a second pitch angle of the second outlet guide vanes and a second speed of the second unducted fan (unducted fan 20 speed is adjusted as a function of blade 21 pitch angle in order to adjust acoustics; see par. 141, top) that results in a second thrust adjustment (the instant pitch angle is a parameter “indicative of thrust output”, see par. 141, middle; and thus changing the blade 21 pitch angle results in a change in thrust, knowledge of one of ordinary skill in the art regarding this area is provided in the pertinent prior art infra); and
adjusting the other of the second pitch angle of the second outlet guide vanes 31 (par. 141, middle states two parameters may adjusted, the second being including vane 31 pitch angle in addition to the unducted fan 20 speed) and the second speed of the second unducted fan.
The first embodiment of Khalid controller (i.e. par. 141) does not disclose adjusting … a first thrust split between the first unducted fan and the first ducted fan; the adjusting the first pitch angle of the first outlet guide vanes is to compensate for the first thrust adjustment (regarding the first engine); adjusting … a second thrust split between the second unducted fan and the second ducted fan; and the adjusting the second pitch angle of the second outlet guide vanes is to compensate for the second thrust adjustment (regarding the second engine).
Khalid par. 163 teaches to compensate of the second thrust adjustment (Khalid teaches “maintaining … thrust output at the rotor assembly and vane assembly” by way of adjusting vane angle). Because the thrust is not increased or decreased but is maintained at the unducted fan 20 and outlet guide vanes 31 combination then the adjustment of the vane 31 pitch angle and fan 20 speed of each respective engine results in first and second thrust adjustments compensating for each other regarding each engine or in other words offsetting or counterbalancing each other (the term compensate can be interpreted as “To offset; counterbalance”; www.thefreedictionary.com).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the Khalid controller first embodiment with adjusting the first pitch angle of the first outlet guide vanes to compensate for the first thrust adjustment; and adjusting the second pitch angle of the second outlet guide vanes to compensate for the first thrust adjustment as taught by Khalid par. 163 in order to facilitate improving acoustic noise levels of each of the first and second engines (see par. 163). Par. 163 points out that the first and second engines can be operated together by the Khalid controller. This is consistent with Khalid par. 42, top, stating reduction of noise by way of blade 21 pitch changes and vane 31 pitch changes.
Khalid teaches adjusting a thrust split. Khalid par. 131 teaches (see fig. 1) adjusting thrust of engine 10 by way adjusting inlet guide vanes to the ducted fan (i.e. the mid-fan) for the third stream bypass duct 1063 (duct 1063 bypasses the combustor and turbines of engine 10; see par. 46) while also adjusting “rotor blade pitch angle” (used to adjust the claimed speed above) and “vane pitch angle” (i.e., outlet guide vane angle).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the current invention to provide Khalid controller first embodiment in view of Khalid par. 163 with adjusting … a first thrust split between the first unducted fan and the first ducted fan; and adjusting … a second thrust split between the second unducted fan and the second ducted fan as taught by Khalid par. 131 in order to facilitate decreasing the thrust of each of the first and second engines or increasing the thrust of each of the first and second engines (see par. 131 top) in order to adapt to different flight phases such as climb, cruise or approach for example (see par. 122, bottom; such paragraph points out that “adjusting thrust output based on … a flight condition (e.g. … climb, cruise, approach, … etc.” ). The thrust split is changed because for each engine (1) the thrust at the unducted fan/outlet guide vanes is maintained by way of the teachings of par. 163 above and (2) the thrust at bypass duct 163 is increased by way of adjustment of the inlet guide vanes used to adjust the thrust of the ducted fan. Thus the claimed “wherein adjusting the first thrust split comprises:” and “wherein adjusting the second thrust split comprises” are met by Khalid.
Regarding claim 18, Khalid teaches (see figs. 1 and 30-31) the current invention as claimed and discussed above. Khalid further teaches wherein the first noise value is based on a measurement from a first sensor (“acoustic sensor” at par. 131, bottom regarding first engine 10 in fig. 10) associated with the first engine 10A, and the second noise value is based on a measurement from a second sensor (“acoustic sensor” at par. 131, bottom regarding second engine 10 in fig. 1) associated with the second engine 10B.
Regarding claim 19, Khalid teaches the current invention as claimed and discussed above. Khalid discloses wherein the first sensor is on (see par. 131, bottom) one of the first engine 10A and the fuselage and the second sensor is on (see par. 131, bottom) one of the second engine 10B and the fuselage of the aircraft.
Claim(s) 21 is/are rejected under 35 U.S.C. 103 as being unpatentable over Khalid as evidenced by Ostdiek, Bushnell and Jones as applied to claim 1 above, and further in view of US Patent 5,259,187 (Dunbar).
Regarding claim 21, Khalid teaches the current invention as claimed and discussed above. Khalid further teaches the controller is configured to adjust the pitch angle of the outlet guide vanes according to a peak noise level and a measurement from a sensor (see par. 163 wherein the “acoustic sensor” is discussed in e.g. par. 131, bottom; if a controller received feedback from an acoustic sensor and makes adjustments to the vanes in order to improve the acoustics then there must be a peak noise the peak noise being the highest noise level that results in an vane angle adjustment). Khalid further teaches using a closure schedule (for unducted fan 20 blades 21) regarding noise (see par. 79). For example Khalid teaches noise reduction can be based on (see par. 42) unducted fan blade pitch angle and outlet guide vane pitch angle and the related aerodynamic interactions (see par. 56, bottom). Khalid is silent specifically a closure schedule (for the outlet guide vanes) that is predetermined based on a peak noise level.
Dunbar teaches (see figs. 1 and 2) a gas turbine 10 and further teaches a closure schedule (for the outlet guide vanes) that is predetermined based on a noise level. Dunbar teaches for each fan speed measuring noise at different outlet guide vane angles and creating a schedule of outlet guide vane angle versus fan speed the schedule resulting in the outlet guide angle with the least noise for each fan speed. Thus applying the format of Dunbar’s teaching of a schedule to Khalid results for each blade angle measuring noise at different outlet guide angles to determine the outlet guide vane angle that results in the least noise for each blade pitch angle.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the current invention to provide Khalid with a closure schedule (for the outlet guide vanes) that is predetermined based on noise level as taught by Dunbar in order to facilitate improving efficiency of engine operation (see Dunbar col. 1, ll. 45-55). the closure schedule can be considered “based on” a peak noise level because the noise reduction of Dunbar includes meeting the closure schedule of Khalid in view of Dunbar is configured to meet noise regulations that serve as maximum or peak noise permissible (see Khalid “regulated noise environments” in par. 68; and see Dunbar “Adjusting vane pitch to minimize engine noise b… will help aircraft meet noise regulations, such as during aircraft descent” at col. 2, ll. 35-40).
Claim(s) 22 is/are rejected under 35 U.S.C. 103 as unpatentable over Khalid as evidenced by Ostdiek, Bushnell, Jones and Dunbar.
Regarding claim 22, Khalid discloses wherein the controller (computing system 210; see pars. 144 and 217 pointing out that instant controller commands blade and vane pitch angles; and see par. 35 stating computing system 210 includes corresponding controllers 1600, 1610, 1700, 1800; such control is referenced in par. 124, top) is configured to adjust the pitch angle of the outlet guide vanes to hold a noise level below a peak noise level by continuously changing (see fig. 28 wherein acoustic signal feedback is used to change “vane pitch position”; this is a “control loop”, see par. 123, and thus one of ordinary skill would understand this to be a feedback loop wherein vane pitch is continuously adjusted) the pitch angle (see par. 124, middle; general discussion of the controller adjusting vane pitch angle is also in pars. 144 and 217) of the outlet guide vanes to achieve an average noise level (because the pitch angle is continuously adjusted to reduce noise there will be an average noise level that is below the peak noise level; average may also refer to an “acceptable level”, see applicant pars. 89 and 92) below a peak noise level (see par. 144; the pitch angle of vanes 31 are adjusted to reduce acoustics; therefore the vanes are adjusted to reduce noise below a noise level such as to a desired noise level, see par. 41, middle and bottom; for example, reducing undesired noise would bring the noise level down, see par. 90, bottom; this would be below a peak level because the aircraft of Khalid must comply with noise regulations that serve as maximum or peak noise permissible (see Khalid “regulated noise environments” in par. 68; and this is evidenced by Dunbar stating “Adjusting vane pitch to minimize engine noise b… will help aircraft meet noise regulations, such as during aircraft descent” at col. 2, ll. 35-40)).
Response to Arguments
Applicant's arguments filed 03/19/2026 have been fully considered but they are not persuasive. Applicant argues “Adjusting rotor speed to reduce noise by synchrophasing, and then further ‘adjust[ing] vane pitch angle and/or rotor plane angle to improve ... noise levels based on other noise sources ... or to control thrust output level’ is fundamentally different from the claimed coordinated control of: (1) closing the outlet guide vane pitch angle to reduce noise, which reduces the thrust contribution from the unducted airflow stream; and (2) increasing the unducted fan speed specifically to compensate for that thrust reduction.” In response Khalid teaches increasing the speed of the unducted fan in order to mitigate the beat interference pattern discussed in par. 156. This is merely adjusting the speed of a first engine to match a speed of the second engine such that the interference of frequencies associated with the respective engines are mitigated. This is a known solution to gas turbine noise mitigation since at least 1993 as discussed in the Pla reference (US Patent 5,221,185) throughout col. 1. It is beneficial to compensate for the increased speed that results in increased thrust of the engine so as to maintain a constant thrust of the instant engine. This prevents the engine whose speed is being increased from having a thrust greater than the thrust of the other engine on the other wing. This prevents asymmetric thrust condition between the engines on each wing of the aircraft that is a goal of Khalid (see par. 161 bottom).
The term compensate can be interpreted as “To offset; counterbalance” (www.thefreedictionary.com). Thus the adjustment of the guide vanes pitch and the adjustment of the speed of the unducted fan counterbalance each other. It is noted that the term “specifically” is not recited in the claims and thus the prior art is not required to address such a term. The claim does not require for example one of the instant adjustments to occur before the other.
Applicant argues against the cited prior Dunbar art regarding claim 21. The arguments were considered, but a new portion of Dunbar was used to reject the claims and therefor the arguments were moot.
Applicant argues against the cited prior art Dunbar regarding claim 22. The arguments were considered, but a new portion of Khalid is used to reject the claims and therefor the arguments were moot.
Pertinent Prior Art
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure:
mid-fan: US 20230073647 (par. 54); GB 2069613 (page 2, ll. 45-50: “'mid fan' … lies in the mid-region of the axial extent of the powerplant); and
changing the unducted fan 20 blade 21 pitch angle results in a change in thrust: US 20180237125 (par. 17: “controller 220 sets blade pitch angle and/or propeller rotational speed of the propeller 120, so as to convert the engine output power from the engine 110 into thrust”).
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.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to MARC J AMAR whose telephone number is (571)272-9948. The examiner can normally be reached M-F 9:00-6:00.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Devon Kramer can be reached at (571) 272-7118. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/MARC AMAR/Examiner, Art Unit 3741
/PHUTTHIWAT WONGWIAN/Supervisory Patent Examiner, Art Unit 3741
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