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 .
This action is in response to the after final filing of 11/10/2025.
Claims 1-5, 7-12, and 14-20 are presented for examination.
Response to Arguments
Applicant’s arguments, see pages 7-8, filed 11/10/2025, with respect to the rejection(s) of claim(s) 1-5, 7-12, and 14-20 under 103 have been fully considered and are persuasive. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground(s) of rejection is made in view of Tian et al. in US Patent Application Publication 2023/0358127 (hereinafter “Tian”).
Applicant's request for reconsideration of the finality of the rejection of the last Office action is persuasive and, therefore, the finality of that action is withdrawn.
The Sibbach reference (US2023/0407761) applied in the final rejection of 7/10/2025 falls under the 102(b)(2)(C) exception for basis of rejection. The finality of that action is withdrawn and a new final rejection is issued herewith.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claim(s) 1-5, 7-12, and 14-20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Calderon in US20210301679 (hereinafter “Calderon”) in view of Tian et al. in US2023/0358127 ( “Tian”).
Regarding claim 1, Calderon discloses a gas turbine engine comprising: a gearbox coupled to a first element and a second element (in Fig. 9, element 30 is a gear box with an input shaft on its right side and output shaft on its left side which are first and second elements); a first speed sensor 42 positioned on an input side of the gearbox, the first speed sensor operable to detect a first speed of the first element; a second speed sensor 40 positioned on an output side of the gearbox, the second speed sensor operable to detect a second speed of the second element (paragraph [0078]); and a control system (paragraph [0019]-[0024]) comprising a processor and a memory coupled to the processor, the processor configured to: receive data from the first speed sensor; receive data from the second speed sensor; detect a trigger event based on the data from the first speed sensor and the data from the second speed sensor; and upon detecting the trigger event, communicate a command to an engine operational system (paragraph [0033]). Calderon does not specifically disclose that the command communicated upon the trigger event is to operate a valve that dumps compressor discharge air pressure or to operate a variable turbine inlet vane to control air flow to a turbine of the gas turbine engine. Instead, Calderon discloses stopping fuel supply upon trigger event detection, as seen in paragraph [0033]. Tian teaches an analogous gas turbine engine, including a control system with speed sensors that monitor shaft rotational velocities, like Calderon (see the abstract of Tian). Tian also discloses that engine shutdown procedures in response to trigger events indicated by the sensors may include reducing fuel supply to the engine, just like Calderon, as well as opening a compressor discharge valve to discharge high-pressure gas to reduce the power output and rotating speed of the engine (abstract).
The Court has held that simple substitution of known element or step for another serves as basis for a prima facie finding of obviousness. See MPEP 2141 and 2143. Here, Calderon contains a device that differs from the instantly claimed device by the substitution of some component with other components (Calderon discloses a control system that shuts off fuel supply in response to a trigger event, versus the instantly claimed configuration of a control system that in response to a trigger event operates a valve to dump compressor discharge air pressure or operates a variable turbine inlet vane to control air flow to the turbine). Tian is evidence that the instantly substituted components were known in the art before the effective filing date of the claimed invention. A person having ordinary skill in the art before the effective filing date of the claimed invention could have substituted one known element for another and the result would have been predictable (simply, it would have been obvious to one of ordinary skill to employ compressor discharge dumping as well as cutting fuel supply as a means to stop engine operation and prevent shaft damage). It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to have modified the gas turbine of Calderon by employing a control system that, in response to a trigger event detected by speed sensors, dumps compressor discharge air in order to reduce engine operation speed and prevent shaft damage, as taught by Tian.
Examiner note: all claim element mapping and prior art citations hereinafter are with respect to the Calderon reference, unless otherwise noted.
Regarding claim 2, Calderon as modified by Tian comprises the gas turbine engine of claim 1, wherein the first element is an input shaft of the gearbox or a component coupled thereto, and wherein the second element is an output shaft of the gearbox or a component coupled thereto (Fig. 9).
Regarding claim 3, Calderon as modified by Tian comprises the gas turbine engine of claim 2, wherein the input shaft is a high-speed shaft, and wherein the output shaft is a low-speed shaft (paragraph [0028]).
Regarding claim 4, Calderon as modified by Tian comprises the gas turbine engine of claim 1, wherein the trigger event is at least one of: exceeding a threshold difference between the first speed and the second speed; or exceeding a threshold rate of change between the first speed and the second speed (paragraph [0028]).
Regarding claim 5, Calderon as modified by Tian comprises the gas turbine engine of claim 1, wherein the command is configured to stop the gas turbine engine (paragraph [0033]).
Regarding claim 7, Calderon as modified by Tian comprises the gas turbine engine of claim 1, wherein one or more of the first speed sensor or the second speed includes a variable reluctance sensor, a surface acoustic wave (SAW) sensor, a blade beta angle sensor, or an electrical machine (paragraph [0031]).
Regarding claim 8, Calderon as modified by Tian comprises a control system (paragraph [0019]-[0024] for a gas turbine engine, the control system comprising: a memory; and a processor coupled to the memory (paragraph [0075]), the processor configured to: receive data from a first speed sensor 42 operable to detect a first speed of a first element coupled to a gearbox of the gas turbine engine, the first speed sensor positioned on an input side of the gearbox (paragraph [0019]-[0024]); receive data from a second speed sensor 40 operable to detect a second speed of a second element coupled to the gearbox, the second speed sensor positioned on an output side of the gearbox; detect a trigger event based on the data from the first speed sensor and the data from the second speed sensor paragraph [0019]-[0024]; see the two sensors 40, 42 on opposite sides of gearbox 30 in Fig. 9); and upon detecting the trigger event, communicate a command to an engine operational system (paragraph [0033]), and that command operates a valve that dumps compressor discharge air pressure or operates a variable turbine inlet vane to control air flow to a turbine of the gas turbine engine based upon the teaching of Tian (equivalent to the rejection based on Calderon as modified by Tian and applied above with respect to claim 1).
Regarding claim 9, Calderon as modified by Tian comprises the control system of claim 8, wherein the first element is an input shaft coupled to the gearbox or a component coupled thereto, and wherein the second element is an output shaft of the gearbox or a component coupled thereto (Fig. 9).
Regarding claim 10, Calderon as modified by Tian comprises the control system of claim 9, wherein the input shaft is a high-speed shaft, and wherein the output shaft is a low-speed shaft (paragraph [0028]).
Regarding claim 11, Calderon as modified by Tian comprises the control system of claim 8, wherein the trigger event is at least one of: exceeding a threshold difference between the first speed and the second speed; or exceeding a threshold rate of change between the first speed and the second speed (paragraph [0028]).
Regarding claim 12, Calderon as modified by Tian comprises the control system of claim 8, wherein the command is configured to stop the gas turbine engine (paragraph [0033]).
Regarding claim 14, Calderon as modified by Tian comprises a method comprising: sensing a first speed of a first element from a first speed sensor positioned on an input side of a gearbox in an engine; receiving data on a second speed of a second element from a second speed sensor positioned on an output side of the gearbox; detecting a trigger event based on the first speed and the second speed; and upon detecting the trigger event, communicating a command to an engine operational system (see paragraphs [0019]-[0024]), and that command operates a valve that dumps compressor discharge air pressure or operates a variable turbine inlet vane to control air flow to a turbine of the gas turbine engine based upon the teaching of Tian (equivalent to the rejection based on Calderon as modified by Tian and applied above with respect to claim 1).
Regarding claim 15, Calderon as modified by Tian comprises the method of claim 14, wherein the first element is an input shaft of the gearbox 30 or a component coupled thereto, and wherein the second element is an output shaft of the gearbox or a component coupled thereto (see gearbox 30 in Fig. 9 fed by the right side input and outputting drive to a fan on the left).
Regarding claim 16, Calderon as modified by Tian comprises the method of claim 14, wherein the command is configured to stop the engine (paragraph [0033]).
Regarding claim 17, Calderon as modified by Tian comprises the method of claim 14, further including: determining a relationship between the first speed and the second speed; and detecting the trigger event upon the relationship exceeding a threshold (paragraph [0067]).
Regarding claim 18, Calderon as modified by Tian comprises the method of claim 14, further including: determining a rate of change of the first speed; determining a rate of change of the second speed; determining a relationship between the rate of change of the first speed and the rate of change of the second speed; and detecting the trigger event upon the relationship exceeding a threshold (paragraph [0029] discloses calculating shaft twist from rotational speed measurements, which necessarily requires determining a rate of change of rotational speed).
Regarding claim 19, Calderon as modified by Tian comprises the method of claim 14, further including: determining a relationship between the first speed and the second speed; determining a rate of change in the relationship (paragraph [0029]-[0031]); and detecting the trigger event upon the rate of change in the relationship exceeding a threshold (paragraph [0033]).
Regarding claim 20, Calderon as modified by Tian comprises the method of claim 14, further including: determining a rate of change of the first speed; determining a rate of change of the second speed; determining a relationship between the rate of change of the first speed and the rate of change of the second speed; determining a rate of change of the relationship; and detecting the trigger event upon the rate of change of the relationship exceeding a threshold (paragraph [0029]-[0031]; “identifying periods of shaft system torsional vibration” and “calculating from the measured rotational speeds for the said identified periods torsional vibration characteristics”, and “identifying a possible unhealthy condition of the torque path when the calculated torsional vibrational characteristics depart from expected torsional vibrational characteristics of the shaft system. In this way, it is also possible to detect unhealthy conditions of the torque path when the calculated torsional vibrational characteristics depart from expected torsional vibrational characteristics.”). In simpler words, in the context of torsional vibrations, the second derivative of rotational speed, or angular acceleration, is a measure of how quickly the rate of change of angular velocity is changing.
Conclusion
THIS ACTION IS MADE FINAL. 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 ELDON T BROCKMAN whose telephone number is (571)270-3263. The examiner can normally be reached Mon-Fri 9am-5pm EST.
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/ELDON T BROCKMAN/Primary Examiner, Art Unit 3799