Method and System for Detecting a Shaft Shear Event
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 .
Information Disclosure Statement
The information disclosure statements (IDS) submitted on 11/06/2024 and 03/09/2026 are being considered by the examiner.
Double Patenting
The nonstatutory double patenting rejection is based on a judicially created doctrine grounded in public policy (a policy reflected in the statute) so as to prevent the unjustified or improper timewise extension of the “right to exclude” granted by a patent and to prevent possible harassment by multiple assignees. A nonstatutory double patenting rejection is appropriate where the conflicting claims are not identical, but at least one examined application claim is not patentably distinct from the reference claim(s) because the examined application claim is either anticipated by, or would have been obvious over, the reference claim(s). See, e.g., In re Berg, 140 F.3d 1428, 46 USPQ2d 1226 (Fed. Cir. 1998); In re Goodman, 11 F.3d 1046, 29 USPQ2d 2010 (Fed. Cir. 1993); In re Longi, 759 F.2d 887, 225 USPQ 645 (Fed. Cir. 1985); In re Van Ornum, 686 F.2d 937, 214 USPQ 761 (CCPA 1982); In re Vogel, 422 F.2d 438, 164 USPQ 619 (CCPA 1970); In re Thorington, 418 F.2d 528, 163 USPQ 644 (CCPA 1969).
A timely filed terminal disclaimer in compliance with 37 CFR 1.321(c) or 1.321(d) may be used to overcome an actual or provisional rejection based on nonstatutory double patenting provided the reference application or patent either is shown to be commonly owned with the examined application, or claims an invention made as a result of activities undertaken within the scope of a joint research agreement. See MPEP § 717.02 for applications subject to examination under the first inventor to file provisions of the AIA as explained in MPEP § 2159. See MPEP § 2146 et seq. for applications not subject to examination under the first inventor to file provisions of the AIA . A terminal disclaimer must be signed in compliance with 37 CFR 1.321(b).
The filing of a terminal disclaimer by itself is not a complete reply to a nonstatutory double patenting (NSDP) rejection. A complete reply requires that the terminal disclaimer be accompanied by a reply requesting reconsideration of the prior Office action. Even where the NSDP rejection is provisional the reply must be complete. See MPEP § 804, subsection I.B.1. For a reply to a non-final Office action, see 37 CFR 1.111(a). For a reply to final Office action, see 37 CFR 1.113(c). A request for reconsideration while not provided for in 37 CFR 1.113(c) may be filed after final for consideration. See MPEP §§ 706.07(e) and 714.13.
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Claims 1, 8, 10-14 and 16-19 are rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1, 9-14 and 16-19 of U.S. Patent No. 11,619,139 in view of Rowe (US 20130319092; “Rowe”). Every element of instant claim 1 is described in reference patent claim 1, except the instant claim recites “speed” instead of “torque” and when shaft shear would be detected, sampling with a sampling period below 200 ms and an analysis by taking a difference between two non-subsequent sampled values. Specifically, reference patent claim 1 recites, “monitoring a current value of rate of reduction of torque of the shaft; providing a threshold value for the rate of reduction of torque of the shaft”. A person of ordinary skill in the art would know there are other shaft values that can be monitored to determine a shaft shear event. In particular, Rowe teaches that a rotational speed deceleration rate can be monitored to determine if the shaft is broken (¶ 0011). Further, Rowe teaches sampling a shaft value every 1 ms to 30 ms and taking a difference between two non-subsequent values characterizing the shaft condition. Therefore, it would have been obvious to a person of ordinary skill in the art at the time of filing the invention to monitor the reference patent’s rate of reduction of speed rather than torque at a sampling period below 200 ms and analyzing results by subtracting two non-subsequent values because deceleration of the rotational speed of the shaft is a good indication that shaft may be broken as taught by Rowe and well-known in the art. The reference patent’s dependent claims listed above include every element of the instant dependent claims listed above.
Claims 1, 3-16 and 18-20 are rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-13 of U.S. Patent No. 12,163,859 in view of Rowe (US 20130319092; “Rowe”). Every element of instant claim 1 is described in reference patent claim 1, except the instant claim recites sampling with a sampling period below 200 ms and an analysis by taking a difference between two non-subsequent sampled values. Rowe teaches sampling a shaft value every 1 ms to 30 ms and taking a difference between two non-subsequent values characterizing the shaft condition. Therefore, it would have been obvious to a person of ordinary skill in the art at the time of filing the invention to monitor the reference patent’s rate of reduction of speed by sampling with a period below 200 ms and analyzing results by subtracting two non-subsequent values because deceleration of the rotational speed of the shaft is a good indication that shaft may be broken as taught by Rowe and well-known in the art. The reference patent’s dependent claims listed above include every element of the instant dependent claims listed above.
Claim Rejections - 35 USC § 112
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
Claims 9-12 are rejected under 35 U.S.C. 112(a) as failing to comply with the enablement requirement.
The claims contain subject matter which was not described in the specification in such a way as to enable one skilled in the art to which it pertains, or with which it is most nearly connected, to make and/or use the invention. Specifically, it is unclear how a person of ordinary skill in the art would set a current threshold capable of accurately differentiating a normal rate of reduction of rotation speed of the shaft from a rate of reduction of rotation speed indicative of a shaft shear by multiplying a base threshold by a current rotation speed factor. The examiner has looked to the disclosure for the scope of the claim which is enabled and found that nowhere in the specification does applicant describe, either in words or figures, a process of determining the base threshold or an appropriate factor. Disclosure ¶ 0066 merely states determining a threshold based on current operating conditions and potentially multiplying by a factor indicative of speed. The examiner believes an ordinarily skilled artisan would not be able to make or use the invention of claim 9 based on the direction provided by the specification because said artisan would not be able to determine an appropriate base threshold and factor without undue experimentation to engineer a working threshold setting process. The examiner has weighed all the evidence for and against enablement of this invention and has concluded based on guidance provided by the MPEP and case law (including the Wands factors) that there is not enough evidence in favor of enablement of this invention. Dependent claims 10-12 are likewise rejected for lack of enablement.
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.
Claims 1-20 are rejected under 35 U.S.C. 112(b) as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor regards as the invention.
Regarding claims 1, the limitation “at a sampling rate below 200 ms” is unclear since millisecond is not a unit of rate. For the purpose of examination, the examiner interprets the limitation as a timespan between samples is below 200 ms. The dependent claims are likewise rejected and interpreted.
Claim Rejections - 35 USC § 102
In the event the determination of the status of the application as subject to 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 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.
Claims 1, 4-5, 8, 13-16 and 18 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Rowe (US 20130319092; “Rowe”).
Regarding claim 1, Rowe discloses, in figures 1-6, a method of detecting a shaft shear event occurring at a shaft of an engine (ABSTRACT, “a method of detecting shaft break for a gas turbine engine”), the method comprising: during operation of the engine (10), at an engine controller ((44) ¶ 0021, Rowe’s processor is an engine control unit): monitoring a current value of a rate of reduction of rotation speed (¶ 0032, Rowe samples rotational speed every 1 to 30 ms and calculates a rate of change of the rotational speed) of the shaft (36), including receiving a plurality of values of rotation speed over time (¶ 0032, Rowe’s measuring device measures the rotational speed substantially continuously or at defined intervals), at a sampling rate below 200 ms (¶ 0032, Rowe’s sampling interval may be between 1 ms and 30 ms), and determining a difference between two non-subsequent ones of said plurality of values of rotation speed (¶ 0036, Rowe’s formula for change of rotational speed includes finding a difference of v3-v1 thus non-subsequent values of rotation speed); providing a threshold value of a rate of reduction of rotation speed of the shaft (¶ 0044, Rowe uses a threshold of rate of change of rotational speed); generating a signal indicative (68a, 48) of the shaft shear event when the current value exceeds threshold value (¶ 0044, Rowe set a first indication of shaft break “if the rate of change of rotational speed is greater than a threshold”).
Regarding claim 4, Rowe discloses, in figures 1-6, the two non-subsequent values of rotation speed are within a timespan below 700 ms (¶ 0032 & 0036, examiner notes if Rowe measures velocity in 30 ms intervals, v1 and v3 are measured 60 ms apart).
Regarding claim 5, Rowe discloses, in figures 1-6, said monitoring the current value of the rate of reduction includes determining the current value of the rate of reduction (¶ 0032, Rowe samples rotational speed every 1 to 30 ms and calculates a rate of change of the rotational speed) for each sampled value of rotation speed (¶ 0036, “he processor 44 calculates the rate of change of rotational speed for each pair of adjacent samples in the sequence”).
Regarding claim 8, Rowe discloses, in figures 1-2 and 6, providing a threshold value includes monitoring operating conditions of the engine and determining a current threshold value based on the current operating conditions (¶ 0044, Rowe’s threshold is a function of an engine power indicator such as exit pressure, corrected shaft speed, or attitude, the examiner asserts Rowe must monitor the engine power indicator to determine the functional value of the threshold), wherein said signal indicative of the shaft shear event (68a) is generated when the current value of the rate of reduction of rotation speed exceeds the current threshold value (¶ 0011 and 0018, Rowe produces a shaft break signal when the first indication is true meaning the rotational speed decelerates more quickly than a threshold deceleration rate).
Regarding claim 13, Rowe discloses, in figures 1-2 and 6, determining whether said shaft shear event is confirmed (¶ 0009, Rowe calculates a second indication which is confirmatory of the first indication to reduce incidence of false shaft break signals) when the signal indicative of shaft shear is generated (68a).
Regarding claim 14, Rowe discloses, in figures 1-2 and 6, determining whether said shaft shear event is confirmed (¶ 0009, Rowe calculates a second indication which is confirmatory of the first indication to reduce incidence of false shaft break signals) includes determining a value of a rate of reduction of speed (¶ 0012, Rowe’s second indication uses a rate of change of rotational speed to determine peaks at a first torsional frequency of the shaft) when the signal indicative of shaft shear (68a) is generated (¶ 0050, Rowes second indication is considered only if the first indication is true), comparing said value of a rate of reduction of speed when the signal indicative of shaft shear is generated to a confirmation rate of reduction threshold value (¶ 0012, Rowes compares the number of peaks at a first torsional frequency of the shaft with a threshold indicating a surge condition), and determining that the shaft shear event is confirmed (see previous comment) when the value of a rate of reduction of speed when the signal indicative of shaft shear is generated is below confirmation rate of reduction threshold value (¶ 0012, Rowe’s second indication is true if the frequency analysis indicates no peak at a first torsional frequency of the shaft, the examiner construes Rowe’s threshold to be 1 peak indicating a surge and below 1 is a shaft shear confirmation).
Regarding claim 15, Rowe discloses, in figures 1-2 and 6, said value of a rate of reduction of speed when the signal indicative of shaft shear is generated is acquired within 1.5 s (¶ 0010, Rowe samples rotation speed every 1 to 30 ms, ¶ 0033, and calculates the rate of change of rotational speed using temporally spaced measurements of the rotational speed between one sample and the next, the examiner believes Rowe calculates rate of reduction of speed for the second indication between 1ms and 30ms after the first indication is generated) of said generating a signal indicative of shaft shear (68a).
Regarding claim 16, Rowe discloses, in figures 1-2 and 6, during operation of the engine (10), at the engine controller (44): in parallel with said monitoring, providing, and generating, performing another method of detecting a shaft shear event (¶ 0047, “additional indication”), said other method including monitoring a current value of a parameter other than a rate of reduction of rotation speed of the shaft (¶ 0047, “vibration measurement”), wherein said signal indicative of the shaft shear event (68a) is generated when at least one of the current value of the rate of reduction of speed of the shaft exceeds the threshold value for the rate of reduction of speed of the shaft (¶ 0011 and 0018, Rowe produces a shaft break signal when the first indication is true meaning the rotational speed decelerates more quickly than a threshold deceleration rate), and the current value of the parameter other than the rate of reduction of speed of the shaft exceeds a threshold value for the parameter other than the rate of reduction of speed of the shaft (¶ 0047, Rowe’s additional indication confirms a shaft break when the vibration measurement is above a threshold).
Regarding claim 18, Rowe discloses, in figures 1-2, during operation of the engine (10), at the engine controller (44): cutting a fuel supply to the engine (10) when the signal indicative of the shaft shear event is generated (¶ 0020, Rowe’s system is arranged “to shut off fuel supply to the engine in response to the shaft break signal”).
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.
Claim 2 is rejected under 35 U.S.C. 103 as being unpatentable over Rowe (US 20130319092; “Rowe”).
Regarding claim 2, Rowe fails to disclose storing rotation speed values in a FIFO storage scheme.
The Examiner takes official notice that using a FIFO to store sensor data is well-known in the art.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use a well-known scheme of storing data in a first in first out manner to store Rowe’s rotation speed values over time. Doing so minimizes host processor activity and lowers overall system power consumption (see evidentiary reference Analog Devices).
Claim 3 is rejected under 35 U.S.C. 103 as being unpatentable over Rowe (US 20130319092; “Rowe”), in view of Kennan (Sciencing, How to Calculate Percentage Reduction, Nov. 2020; "Kennan").
Regarding claim 3, Rowe fails to disclose determining a proportional difference between rotation speed values.
Kennan teaches determining a rate of reduction by subtracting a final amount from an initial amount and dividing by the initial amount (see Kennan’s article, p. 2, lines 6 and 8).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use Kennan’s scheme of determining rate of reduction to teach Rowe a process of determining a proportion between the difference and at least one of said values of rotation speed to produce a unitless scaled reduction value. Doing so increases useability making the value independent of rotational speed.
Claims 6-7 are rejected under 35 U.S.C. 103 as being unpatentable over Rowe (US 20130319092; “Rowe”) as applied to claim 1 above, and further in view of Wood (US 20200240285; “Wood”).
Regarding claim 6, Rowe discloses, in figures 1-2, receiving the plurality of values of rotation speed over time (¶ 0032, Rowes measuring device is arranged to measure the rotational speed) from a speed probe ((42) ¶ 0032, Rowe measure rotational speed using a speed probe or other device capable of measuring rotational speed) coupled (see figure 2, examiner notes Rowes speed probe is connected to the shaft through the intermediate pressure compressor) to the shaft (36).
Rowe fails to explicitly disclose the measuring device is a phonic wheel sensor.
Wood teaches, in figure 11, a rotational speed measuring device (¶ 0004, Wood uses phonic wheels and sensors to measure shaft speed) is a phonic wheel sensor (1, 2).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use Wood’s phonic wheel sensor as Rowe’s device capable of measuring rotational speed since doing so allows all the claimed elements to continue to operate in a typical manner and yields predictable results. Doing so provides a reliable way of measuring shaft rotational speed.
Regarding claim 7, Rowe and Wood disclose, in Rowe’s figures 1-2, the shaft (Rowe (34)) is a low pressure shaft (Rowe, ¶ 0002, “low pressure shaft”) having a turbine (Rowe (26)), a compressor (Rowe (14)), and an output end opposite the turbine (Rowe (26)), the phonic wheel sensor (Wood (1,2)) being positioned along a length of the low pressure shaft (Rowe (34)) between the compressor (Rowe (14)) and the output end (see Rowes’s figure 2, examiner notes the speed probe is located at the output end of the compressor).
Claim 19 is rejected under 35 U.S.C. 103 as being unpatentable over Rowe (US 20130319092; “Rowe”) as applied to claim 1 above, in view of Thompson (US 20010000090; “Thompson”).
Regarding claim 19, Row discloses monitoring operating conditions (¶ 0033, Rowe’s processor receives speed measurements from a measuring device mounted to a shaft component therefore the processor monitors operation conditions) of the engine (10).
Rowe fails to disclose when the method of detecting a shaft shear event is activated.
Thompson teaches detecting shaft decoupling during startup (¶ 0018, “FIG. 5 is a logic diagram illustrating the steps necessary for detecting shaft decoupling and the sequence for shutting down the engine when a decouple is detected during initial startup, or running at low power settings.”).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to incorporate Thompson’s scheme of detecting a shaft shear event when the engine is in startup into Rowe’s method of detecting shaft shear. Doing so increases safety by providing a process for shutting off fuel during a shaft shear event throughout operation of the engine.
Allowable Subject Matter
A search has not revealed the method of claims 17 and 20 including the limitations of the base claims and the intervening claims; however a final determination of allowability cannot be made until the nonstatutory double patenting and 112(b) rejections set forth in this Office action are overcome.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Analog devices (ADXL375revB data sheet, 2015) discloses the benefits of a sensor data FIFO as related to processing activity and power consumption.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to TIMOTHY P GRAVES whose telephone number is (469)295-9072. The examiner can normally be reached M-F 8 a.m. - 5 p.m..
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Peter Macchiarolo can be reached at 571-272-2375. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/TIMOTHY P GRAVES/Primary Examiner, Art Unit 2855
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