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 .
Election/Restrictions
Applicant’s election of Invention I (Claims 1-11) in the reply filed on 04/10/2026 is acknowledged. Claims 12-20 are withdrawn.
Claim Objections
Claim 9 is objected to because of the following informalities:
Claim 9, line 3, change: “an oil supply for the hydraulic actuator.”
Appropriate correction is required.
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 (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.
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 1-2 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Pedrami et al. (U.S. 10,072,796).
Regarding claim 1, Pedrami et al. discloses a method for controlling an actual rotational speed of a variable-pitch propeller of an aircraft (Col. 1, lines 10-25) where a pitch of the variable-pitch propeller is adjustable using a hydraulic actuator (Col. 2, lines 33-40), the method comprising:
determining a speed error between the actual rotational speed of the variable-pitch propeller (actual speed of propeller 102, Col. 2, line 60) and a set point rotational speed (requested speed, Col. 2, lines 58-60) for the variable-pitch propeller (Col. 2, lines 58-66);
determining a requested oil flow for delivery to the hydraulic actuator (oil flow request shown in Fig. 2, Col. 3, lines 8-15) based on the speed error (i.e., control diagram in Fig. 2 shows that the oil flow request is based on the difference in speed (i.e., the speed error between the requested speed and actual speed);
determining an estimated oil leakage rate out of the hydraulic actuator (i.e., via the estimate from the leakage flow rate calculator 402, Col. 3, lines 37-55);
determining a leakage trim multiplier having a value (i.e., bias gain value, Col. 4, lines 48-52) based on the speed error (as shown by the control diagrams in Fig. 4, the bias gain forms the leakage compensation component, wherein as shown in Fig. 3, the leakage compensation component is formed from the compensated oil flow request, wherein in Fig. 2, the compensated oil flow request is formed from the speed error, which is the difference between the actual speed and the requested speed);
determining a trimmed oil leakage rate out of the hydraulic actuator by multiplying the estimated oil leakage rate (in Fig. 4, leakage flow rate) by the leakage trim multiplier (i.e., at 406, the leakage flow rate is multiplied by bias gain multiplier);
adding (i.e., at location 206, Fig. 2) the trimmed oil leakage rate (i.e., leakage compensation component shown in Fig. 2) to the requested oil flow (oil flow request, Fig. 2) to generate a commanded oil flow (i.e., compensated oil flow request, Fig. 2); and
delivering the commanded oil flow to the hydraulic actuator (Col. 2, lines 33-42) to adjust the pitch of the variable-pitch propeller and correct the speed error (i.e., sent to the meter the oil flow to the propeller 102, Col. 3, lines 14-16; error, Col. 2, lines 65-67, Col. 3, lines 1-7).
Regarding claim 2, Pedrami et al. discloses wherein the requested oil flow is determined using a feedback controller that is devoid of an integral term (i.e., the controller 204 shown in the requested oil flow in Fig. 2 is a proportional controller (i.e., a P controller, Col. 3, line 5, which lacks an integral term)).
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 3 is rejected under 35 U.S.C. 103 as being unpatentable over Pedrami et al. (U.S. 10,072,796) in view of Meunier (US 2021/0180525 A1).
Regarding claim 3, Pedrami et al. discloses of a controller (204), but does not disclose wherein the feedback controller is a proportional-derivative feedback controller.
Meunier teaches of a speed governing a variable pitch propeller ([0002]), which is within the same field of endeavor as the claimed invention. Specifically, Meunier teaches of an analogous feedback controller (300) that is used to modulate oil flow to the propeller to obtain a rotational speed via an angle of the blades ([0022],[0020]). Meunier teaches that the controller is designed as a proportional derivative controller ([0022]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Pedrami et al. in view of Meunier by using a proportional-derivative controller as the feedback controller disclosed in Pedrami et al. as it widely known in the controller art that a proportional-derivative controller can be used as a type of controller in order to provide stability and feedback to the control system of governing the speed of a propeller.
Allowable Subject Matter
Claims 4-11 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
Regarding claim 4, Pedrami et al. fails to disclose or suggest wherein the leakage trim multiplier (i.e., bias gain value, Col. 4, lines 48-52) is based on a time integral of the speed error.
Claims 5-9 would be allowable due to their dependency on claim 4.
Regarding claim 10, Pedrami et al. fails to disclose or suggest determining the leakage trim multiplier by: integrating the speed error over time to obtain a time integral of the speed error; and multiplying the time integral of the speed error by a gain.
Regarding claim 11, Pedrami et al. fails to disclose wherein the leakage trim multiplier (i.e., bias gain value, Col. 4, lines 48-52) is based on a time integral of the speed error.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ERIC J ZAMORA ALVAREZ whose telephone number is (571)272-7928. The examiner can normally be reached Monday-Friday 7:30 am- 5:00 pm EST alternating Fridays off.
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/ERIC J ZAMORA ALVAREZ/Primary Examiner, Art Unit 3745 05/18/2026
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