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 .
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.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Internet/E-mail Communication
In order to permit communication regarding the instant application via email, Applicant is invited to file form PTO/SB/439 (Authorization for Internet Communications) or include the following statement in a filed document or remarks of a filed response (see MPEP 502.03 II):
Recognizing that Internet communications are not secure, I hereby authorize the USPTO to communicate with the undersigned and practitioners in accordance with 37 CFR 1.33 and 37 CFR 1.34 concerning any subject matter of this application by video conferencing, instant messaging, or electronic mail. I understand that a copy of these communications will be made of record in the application file.
If such authorization is provided, please include an email address in the remarks of a filed response. The examiner’s e-mail address is CHRISTOPHER.LEGENDRE@USPTO.GOV.
Response to Amendment
Applicant’s amendments filed 28 with respect to the specification have been fully considered and are deemed to overcome the previous objection(s).
Applicant’s amendments filed 28 August 2025 with respect to the claims have been fully considered. Any claim objections not repeated herein are considered to be overcome by the amendments.
Response to Remarks/Arguments
Applicant's remarks/arguments filed 28 August 2025 stating “One of ordinary skill in the art having read the specification of the instant application would understand that ‘coefficient of lift’ is a well-established aerodynamic coefficient. A coefficient is, by definition, a constant factor rather than a variable factor” have been fully considered. The Office respectfully notes that a coefficient of lift (CL) is not a constant - one having ordinary skill in the art would understand that the coefficient of lift for a given airfoil body is altered by angle of attack, for example. Regardless, the issue(s) identified by the previous corresponding 35 U.S.C. 112 concerns the method of determination of the CL (and, thus, the structure CL is intended to represent), not whether or not CL is a constant.
Applicant's remarks/arguments filed 28 August 2025 stating “Thus, Applicant submits that the written description includes description of sufficient, relevant, identifying characteristics that allow a person skilled in the art to recognize that the inventor had possession of the claimed invention” have been fully considered. The Office provides the following response: A CL for a three-dimensional airfoil body is dictated by the three-dimensional flow field thereon and, thus, is determined experimentally. The CL describes and/or represents the three-dimensional flow field produced by the entire three-dimensional shape of the airfoil body and, thus, the determination of the CL does not imply and/or permit a determination of the CL for portions/segments of the airfoil body. In the instant case, Applicant assigns different CLs to portions/segments of the airfoil body, but there is no indication as to how these CLs are determined (i.e., the method used for their determination, namely/primarily with regards to the flow velocity profile across the span of the “propeller blade”) and/or what flow interactions they are intended to represent, which is/are critical to defining the resulting structure:
using an interpretation in which “a first blade section… defining a first coefficient of lift; a second blade section… defining a second coefficient of lift different than the first coefficient of lift” pertains to consideration of three-dimensional flow field resulting from the entire propeller blade (i.e., in which the flow velocity profile varies across the span of the “propeller blade”), per the above explanation, it is erroneous/nonsensical to assign different CLs to portions/segments of the claimed “propeller blade”;
using the only other possible reasonable interpretation of “a first blade section… defining a first coefficient of lift; a second blade section… defining a second coefficient of lift different than the first coefficient of lift” in light of the disclosure, i.e. that the CL of each “first blade section” and “second blade section” are both determined using a wing-type analysis (i.e., in which the flow velocity is constant across the span of the respective “section”) independently such that “first blade section” has a particular wing-geometry (e.g., airfoil shape) and “second coefficient of lift” has a different wing-geometry (e.g., airfoil shape), it is noted that “first coefficient of lift” and “second coefficient of lift” cannot / do not represent the CL for the respective sections of the claimed propeller blade, but, rather, represent CLs for completely different three-dimensional airfoil bodies operating with a flow velocity profile that is entirely different than that of a propeller blade.
Accordingly, the originally filed disclosure does not sufficiently describe the structure corresponding to “A propeller blade comprising:… a first blade section… defining a first coefficient of lift; a second blade section… defining a second coefficient of lift different than the first coefficient of lift”.
Applicant's remarks/arguments filed 28 August 2025 stating “Support for the “non-constant” rate language of amended claim 11 can be found in at least paragraph [0038] of the Specification of the instant application as originally filed” have been fully considered. According to MPEP 2163.03 V, “The written description requirement is not necessarily met when the claim language appears in ipsis verbis in the specification. ‘Even if a claim is supported by the specification, the language of the specification, to the extent possible, must describe the claimed invention so that one skilled in the art can recognize what is claimed. The appearance of mere indistinct words in a specification or a claim, even an original claim, does not necessarily satisfy that requirement.’ Enzo Biochem, Inc. v. Gen-Probe, Inc., 323 F.3d 956, 968, 63 USPQ2d 1609, 1616 (Fed. Cir. 2002)”. In the instant case, the Office respectfully notes that the disclosure does not sufficiently describe the implications and/or requirements of “constant rate of change” and/or “non-constant rate of change” as it/they pertain(s) to “airfoil shape” - i.e.., is “non-constant” evaluated locally or globally with respect to the airfoil cross-section? in what geometric dimension is “rate of change” to be evaluated/applied?
Applicant's remarks/arguments filed 28 August 2025 stating “It is important not to equate breadth of a claim with indefiniteness. See M.P.E.P. §2173.04 [R10.2019] ‘A broad claim is not indefinite merely because it encompasses a wide scope of subject matter provided the scope is clearly defined’” have been fully considered. The Office respectfully notes that the corresponding 35 U.S.C. 112(b) rejections identify an issue with meaning, not breadth, of the concept described by the instant “rate of change” limitations.
Applicant’s remarks/arguments filed 28 August 2025 stating “According to the Norwood translation, the first section 30 of the blade 34 can be a lifting section or wing-shaped section, which may be any cross section or profile which is Shaped 50 as to produce lift force on at least one rotational direction. Id. p. 4, ¶ 3. However, the Norwood translation fails to describe the first blade section defining a first coefficient of lift, the second blade section defining a second coefficient of lift different than the first coefficient of lift, and wherein the first coefficient of lift is higher than the second coefficient of lift, as set forth in independent claim 1” have been fully considered and they are persuasive. The Office acknowledges that although Norwood discloses airfoil sections having shapes (i.e., symmetrical versus cambered) that generally correspond with differing lift characteristics, Norwood also discloses that these airfoil sections have differing dimensions (i.e., thicknesses and/or chords) - accordingly, Norwood cannot be evaluated in regards to the CLs (in any sense) of the various airfoil sections. The previous corresponding prior art rejections are withdrawn.
Applicant’s remarks/arguments filed 28 August 2025 stating that the amendments to claim 11 overcome the previous prior art rejections have been fully considered and they are persuasive.
Claim Objections
Claim 19 is objected to for the following informalities:
In claim 19, “the transition section defines a non-linear transition span in which a rate of change of airfoil shape from the first airfoil to the second airfoil between the transition start point and the transition end point is not constant and” should be deleted (since it is duplicative of limitations in claim 11).
Appropriate correction is required.
Claim Rejections - 35 USC § 112
The following is a quotation 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 1-11 and 14-22 are rejected under 35 U.S.C. 112(a) for failing the written description requirement.
In claim 1, the limitation recited as “a first blade section… defining a first coefficient of lift” and/or “a second blade section… defining a second coefficient of lift” and/or “the first coefficient of lift is higher than the second coefficient of lift” was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that Applicant, at the time the application was filed, had possession of the claimed invention. According to MPEP 2163.03 (V), an original claim may lack written description support when the claim defines the invention in functional language specifying a desired result but the disclosure fails to sufficiently identify how the function is performed or the result is achieved. According to MPEP 2163 (I)(A), issues of adequate written description may arise even for original claims, for example, when an aspect of the claimed invention has not been described with sufficient particularity such that one skilled in the art would recognize that the applicant had possession of the claimed invention at the time of filing. In the instant case, coefficient of lift (CL) of an airfoil body is a parameter that is representative of a functional aspect that is dependent upon operational parameters (namely, the three-dimensional flow field produced by the three-dimensional geometry of the airfoil body, which is determined, in part, by the flow velocity profile across the airfoil body), but the originally filed disclosure is silent and/or ambiguous as to the conditions required for determining the instant CL – i.e., is each CL (1) determined in the context of the respective “airfoil section” being part of the same rotor blade (in which the flow velocity varies across the span) or (2) determined merely from the properties of the respective (two-dimensional) airfoil cross-section (i.e., using the same uniform airflow velocity profile for each “section”, or using a different uniform airflow velocity profile for each “section”, or using the same non-uniform velocity profile for each “section”, or using a different non-uniform airflow velocity profile for each “section”, etc.)? If option (1), then it is noted that it is erroneous/nonsensical to assign different CLs to portions/segments of the claimed “propeller blade” (since a CL for a propeller blade in this scenario would be representative of the entirety of the propeller blade). If option (2), then it is noted that the CLs cannot / do not represent the CL for the respective sections of the claimed “propeller blade”, but, rather, represent CLs for completely different three-dimensional airfoil bodies operating with a flow velocity profile that is entirely different than that of the claimed “propeller blade” (note: the three-dimensional flow field and, thus, the resulting CL of a given three-dimensional airfoil body geometry is unique and, thus, cannot be reproduced in a piecemeal fashion). Accordingly, the originally filed disclosure does not sufficiently describe how the instant inequality, relying on different functional parameters that vary based (at least) on operating conditions, is realized. Due to similar issues and/or furtherance of the aforementioned issues, this rejection also applies to claims 2, 3, 6, 7, 19, 20, and 21. Due to dependency, this rejection also applies to claims 2-10.
In claim 11, the limitation recited as “a rate of change of airfoil shape from the first airfoil to the second airfoil… is not constant” was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that Applicant, at the time the application was filed, had possession of the claimed invention. According to MPEP 2163 (I)(A), issues of adequate written description may arise even for original claims, for example, when an aspect of the claimed invention has not been described with sufficient particularity such that one skilled in the art would recognize that the applicant had possession of the claimed invention at the time of filing. In the instant case, a gradual transition in shape is geometrically complex and the originally filed disclosure is silent and/or ambiguous as to what constitutes a change in shape having a non-constant rate of change – i.e., there is no description as to how such a transition and/or the iterative changes thereof are tracked/quantified such that they can be evaluated based on a rate of change. If such a transition is considered to be tracked/quantified based on identifying analogous points on the initial shape and the final shape, it is noted that, apart from easily identifiable locations like the leading edge and trailing edge, the determination that any two given points are analogous is subjective. Furthermore, taking the case of leading edges and trailing edges being used to track/quantify the transition, if the airfoil shape change is such that the leading edge location displaces more than the trailing edge location across the transition, thus requiring differing rates of change per length for these locations, does this constitute a non-constant rate of change? Stated another way, is the rate of change considered globally or locally? If globally, then how can a single rate of change characterize a change between dissimilar shapes (as is required by “the first airfoil is different than the second airfoil”)? Furthermore, there is no indication as to the dimension across which rate of change is to be evaluated/applied. Accordingly, the originally filed disclosure does not describe the instant property in sufficient detail. Due to similar issues, this rejection also applies to claims 18-20. Due to dependency, this rejection also applies to claims 14-22.
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 11 and 14-22 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.
In claim 11, the limitation recited as “a rate of change of airfoil shape from the first airfoil to the second airfoil… is not constant” renders the claim indefinite since the originally filed disclosure is ambiguous as to what constitutes a change in shape having a non-constant rate of change – e.g., if the airfoil shape change is such that the leading edge location displaces more than the trailing edge location across the transition, thus requiring differing rates of change per length for these locations, does this constitute a constant rate of change (i.e., is the rate of change considered globally or locally?)? Due to similar issues, this rejection also applies to claims 18-20. Due to dependency, this rejection also applies to claims 14-22.
In claim 20, the limitation recited as “the transition section defines a linear transition span in which a rate of change of airfoil shape form the first airfoil to the second airfoil between the transition start point and the transition end point is constant” renders the claim indefinite since it is contradictory to and/or negating of the antecedent limitation “the transition section defines a non-linear transition span in which a rate of change of airfoil shape from the first airfoil to the second airfoil between the transition start point and the transition end point is not constant” (claim 11).
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 extension fee 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 CHRISTOPHER RYAN LEGENDRE whose telephone is (571)270-3364 and email is christopher.legendre@uspto.gov. The examiner can normally be reached M-F 9AM-5PM ET.
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/CHRISTOPHER R LEGENDRE/Primary Examiner, Art Unit 3745