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 .
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
Claim Rejections - 35 USC § 102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale or otherwise available to the public before the effective filing date of the claimed invention.
(a)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention.
Claim(s) 1-3, 7-8, and 10-13 is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Terwilliger 11167858.
Regarding claim 1, Terwilliger teaches a method of altering a thrust (e.g. Fig 7) of a hybrid-electric gas turbine engine (Figs 1-2)
having a core (incl. 24, 26, 28) including a compressor section (44, 52, 204) a combustor (56), a turbine section (54, 46, 208), and an exhaust section (downstream of 54, 46) arranged to define a working airflow path (therethrough; col.5 ll.4-21, col.7 ll.16-27), and
with a spool (30, 32, 202) defined by a set of compressor blades of the compressor section (in 44, 52, 204) and a set of turbine blades of the turbine section (in 54, 46, 208) coupled to a rotatable shaft (50, 40, 206), and
an electric machine (212) operably coupled to the rotatable shaft (Fig 2), the method comprising:
operating a flow modulator (205) to alter a pressure of a working airflow in the working airflow path to alter a torque acting on the spool (205 may be a variable area nozzle, which alters pressure of the working airflow upstream thereof, which alters the torque acting on the spool in the working airflow; col.7 ll.25-27; Fig 2), and
operating the electric machine to at least partially compensate for the altered torque (“load”) acting on the spool (col.7 ll.16-45);
wherein the thrust is altered while at least one of:
(i) maintaining a spool speed of the spool at a spool speed threshold (Figs 7-8 show thrust throttling and low spool speed remaining constant at 804)
(ii) limiting a rate of change of the spool speed to a rate of change threshold (Figs 7-8 show thrust throttling and low spool speed remaining constant such that rate of change is zero).
Note, although Figures 7-8 are exemplary operations with respect to flow modulator (205) being a variable pitch fan, the essential teaching of Terwilliger is to use the electric machine to provide the requested thrust and cycle response without (or while mitigating) engine cycle response lag. Thus, any manipulation of any flow modulator (205), including variable exhaust nozzle, that enables thrust throttling that oscillates about a single value as shown in Fig 7 can be compensated by the electric machine response to hold spool speed constant and track the desired thrust throttling profile as is the desired operation taught by Terwilliger (col.7 ll.16-60).
Regarding claim 2, Terwilliger teaches all the limitations of the claimed invention as discussed above. Terwilliger further teaches maintaining the spool speed at or below the spool speed threshold (not altering the spool speed per Fig 8), and torque from the electric machine fully compensating for the altered torque acting on the spool to alter the thrust (212 is fully compensating for thrust throttling in Figs 7-8 to achieve constant spool speed; col.8 l.65 – col.9 l.11).
Regarding claim 3, Terwilliger teaches all the limitations of the claimed invention as discussed above. Terwilliger further teaches operating the flow modulator includes altering a cross-sectional area of a variable exhaust nozzle of the exhaust section (col.7 ll.26-27).
Regarding claim 7, Terwilliger teaches all the limitations of the claimed invention as discussed above. Terwilliger further teaches the rate of change threshold is equal to 0% of the spool speed per minute (Fig 8; rate of change is zero, which is zero percent of any value).
Regarding claim 8, Terwilliger teaches all the limitations of the claimed invention as discussed above. Terwilliger further teaches the hybrid-electric gas turbine engine includes a second spool (one of 44/46/40 and 52/54/50 is the first spool, and the other is the second spool; both can be represented by spool 202 of Fig 2 incl.204/206/208; col.5 ll.4-21) defined by a second set of compressor blades and a second set of turbine blades coupled to a second rotatable shaft (Figs 1-2), and
a second electric machine coupled to the second spool (col.7 ll.46-60 teaches one electrical machine 212 can be used on each shaft/spool);
wherein operating the flow modulator alters a second spool torque acting on the second spool (variable area exhaust 205 alters torque on both spools); and
wherein altering the thrust generated by the hybrid-electric gas turbine engine includes:
maintaining a second spool speed of the second spool at or below a second spool speed threshold while altering the thrust (as discussed above, the control concept of Figs 7-8 for Fig 2, applies to both spools of Fig 1 and operation of the variable exhaust nozzle with oscillating thrust; col.5 ll.4-21; col.7 ll.16-60), and
operating the second electric machine to at least partially compensate for the altered second spool torque acting on the second spool (as discussed above; col.5 ll.4-21; col.7 ll.16-60).
Regarding claim 10, Terwilliger teaches all the limitations of the claimed invention as discussed above. Terwilliger further teaches altering the thrust generated by the hybrid-electric gas turbine engine includes increasing the thrust provided by the hybrid- electric gas turbine engine (in Fig 7, thrust is - relatively - increased three times in an example autothrottle operation; see below) and
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wherein increasing the thrust provided by the hybrid-electric gas turbine engine includes increasing energy provided via the combustor by increasing fuel flow to the combustor (col.1 ll.10-17 teaches thrust throttling with fuel flow control, which increases energy when increased fuel flow is supplied; this includes auto-throttle operations, by definition; see evidentiary reference: Wikipedia entry titled “Autothrottle”, 13 February 2023, retrieved via Wayback Machine, https://web.archive.org/web/20230213092919/https://en.wikipedia.org/wiki/Autothrottle).
Regarding claim 11, Terwilliger teaches all the limitations of the claimed invention as discussed above. Terwilliger further teaches altering the thrust includes decreasing the thrust, the working airflow path is altered to decrease the pressure of the working airflow and decrease the torque acting on the spool, and the electric machine is operated to increase the torque acting on the spool (Figs 7-10; show an initial thrust increase followed by a thrust decrease, the thrust decrease accompanied by flow modulator decreasing torque acting on the spool to achieve the thrust response, but this results in reduced ability to subsequently increase thrust, thus electric machine is operated to increase torque in the subsequent thrust increase to maintain constant speed and ensure subsequent modulations in thrust).
Regarding claim 12, Terwilliger teaches all the limitations of the claimed invention as discussed above. Terwilliger further teaches the torque increase provided by operation of the electric machine is within 50% of the torque decrease provided by altering the working airflow path (the difference between the thrust decrease achieved by flow modulator alone, 702 in Fig 7, relative to the previous thrust increase, is within 50% of the subsequent thrust increase provided by the electric motor per Figs 7, 10).
Regarding claim 13, Terwilliger teaches all the limitations of the claimed invention as discussed above. Terwilliger further teaches determining the rate of change threshold, at least in part, according to a maximum generator capacity of the electric machine (the rate of change threshold under any operation can only be maintained within the range the maximum generator capacity of the electric machine can compensate for).
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 5-6 and 9 is/are rejected under 35 U.S.C. 103 as being unpatentable over Terwilliger in view of Wikipedia (entry titled “Autothrottle”, 13 February 2023, retrieved via Wayback Machine, https://web.archive.org/web/20230213092919/https://en.wikipedia.org/wiki/Autothrottle).
Regarding claim 5, Terwilliger teaches all the limitations of the claimed invention as discussed above. Terwilliger further teaches the spool can be a high pressure spool of the engine (col.5 ll.4-21), and the thrust modulation at constant spool speed of Figs 7-10 being an autothrottle operation (col.8 ll.38-51).
Terwilliger does not teach the constant speed spool threshold being 95-105% of cruising speed of the spool.
However, Wikipedia teaches autothrottle can be used to maintain target airspeed and power (p.1, section titled “Working modes”) during various portions of the flight envelope including cruise (p.1, section titled “Usage”; i.e. 100% cruising operation).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use the system/method of Terwilliger to achieve 100% cruising speed during autothrottle, because Wikipedia teaches it was known to use autothrottle during cruise (p.1).
Regarding claim 6, Terwilliger teaches all the limitations of the claimed invention as discussed above. Terwilliger further teaches the spool can be a low pressure spool of the engine (col.5 ll.4-21), and the thrust modulation at constant spool speed of Figs 7-10 being an autothrottle operation (col.8 ll.38-51).
Terwilliger does not teach the constant speed spool threshold being 90-110% of cruising speed of the spool.
However, Wikipedia teaches autothrottle can be used to maintain target airspeed and power (p.1, section titled “Working modes”) during various portions of the flight envelope including cruise (p.1, section titled “Usage”; i.e. 100% cruising operation).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use the system/method of Terwilliger to achieve 100% cruising speed during autothrottle, because Wikipedia teaches it was known to use autothrottle during cruise (p.1).
Regarding claim 9, Terwilliger teaches all the limitations of the claimed invention as discussed above. Terwilliger further teaches the spool is a high-pressure (HP) spool and the second spool is a low-pressure (LP) spool (col.5 ll.4-21), and the thrust modulation at constant spool speed of Figs 7-10 being an autothrottle operation (col.8 ll.38-51).
Terwilliger does not teach the constant spool speed threshold is equal to or between 95% and 105% of a cruising speed of the spool, and equal to or between 70% and 110% of a cruising speed of the second spool.
However, Wikipedia teaches autothrottle can be used to maintain target airspeed and power (p.1, section titled “Working modes”) during various portions of the flight envelope including cruise (p.1, section titled “Usage”; i.e. 100% cruising operation for both spools).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use the system/method of Terwilliger to achieve 100% cruising spool speeds during autothrottle, because Wikipedia teaches it was known to use autothrottle during cruise (p.1).
Potentially Allowable Subject Matter
Claim 21 appears to be allowable over the prior art
Response to Arguments
Applicant's arguments filed 13 January 2026 have been fully considered but they are not persuasive.
Applicant argues that Terwilliger does not teach “the thrust is altered while at least one of (i) maintaining a spool speed of the spool at or below a spool speed threshold or (ii) limiting a rate of change of the spool speed to a rate of change threshold” because Applicant asserts that Figs 7-8 of Terwilliger teach “management of [thrust] oscillations caused by a[/the] variable pitch fan”
However, whether or not the thrust alteration is caused by the variable pitch fan, Figs 7-8 are still teaching a thrust alteration while maintaining constant speed. Furthermore, col.8 l.38 - col.9 l.22 of Terwilliger teaches that the thrust alteration/oscillation depicted in Fig 7 (and constant speed in Fig 8) is an autothrottle event. Autothrottle is defined (by Wikipedia) as “a system that allows a pilot to control the power setting of an aircraft's engines by specifying a desired flight characteristic, rather than manually controlling the fuel flow. The autothrottle can greatly reduce the pilots' work load and help conserve fuel and extend engine life by metering the precise amount of fuel required to attain a specific target indicated air speed, or the assigned power for different phases of flight. A/T and AFDS (Auto Flight Director Systems) can work together to fulfill the whole flight plan.” Thus, even if Applicant intends the thrust alteration to be a result of fuel flow changes to the combustor (as recited in Claim 10), Terwilliger still teaches such thrust alteration by fuel flow adjustment to maintain constant speed under varying conditions per the definition of autothrottle and col.8 l.38 - col.9 l.22 describing Figs 7-8 as an autothrottle event.
Other Relevant Art
Cheng CN115587499A teaches acceleration and deceleration (transient events) affecting cycle fatigue.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Correspondence
Any inquiry concerning this communication or earlier communications from the examiner should be directed to STEPHANIE SEBASCO CHENG whose telephone number is (469)295-9153. The examiner can normally be reached on 1000-1600 ET.
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/STEPHANIE SEBASCO CHENG/Primary Examiner, Art Unit 3741