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 .
Response to Arguments
Applicant’s arguments, see Remarks, filed 10/23/2025, with respect to the rejection of claims 16-20, 23, 25-29, 31, and 33-34 have been fully considered and are persuasive. The rejection of claims 16-20, 23, 25-29, 31, and 33-34 have been withdrawn.
Applicant’s arguments, with respect to the rejection(s) of claim(s) 35 under 35 USC 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 Therefore, the rejection has been withdrawn.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 Gaskell et al. (US 2021/0189971) and Simonassi et al. (“An Experimental Test Case for Transonic Low-Pressure Turbines - Part I: Rig Design, Instrumentation, and Experimental Methodology”).
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(s) 35 is/are rejected under 35 U.S.C. 103 as being unpatentable over Gaskell et al. (US 2021/0189971; hereinafter Gaskell) in view of Simonassi et al. (“An Experimental Test Case for Transonic Low-Pressure Turbines - Part I: Rig Design, Instrumentation, and Experimental Methodology”; hereinafter Simonassi).
Regarding claim 35, Gaskell (Fig. 1) discloses a turbofan engine (10) comprising: a low-pressure turbine (19) having exactly three stages (Paragraph 0264, lines 1-3).
Gaskell fails to disclose that at least two of the three stages each having a transonic airfoil.
Simonassi (Abstract) teaches that ultra high bypass ratio geared turbofans can help reduce the environmental impact of aircrafts. Simonassi (Abstract) teaches that geared architecture allows for higher rotational speeds of the low pressure turbine which can offer the benefit of increased efficiency and savings in engine weight. Simonassi (Abstract) teaches that the low pressure turbine operates at transonic exit Mach numbers. It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify Gaskell by forming the turbofan engine as a geared turbofan engine to allow the low pressure turbine to operate at transonic exit Mach numbers, as taught by Simonassi, in order to help improve the efficiency of the engine.
Allowable Subject Matter
Claims 16-29, 31-34, and 36-38 are allowed.
The following is a statement of reasons for the indication of allowable subject matter:
Regarding claim 16:
Closest prior art: Gallagher et al. (US 9,909,505) and Simonassi et al. (“An Experimental Test Case for Transonic Low-Pressure Turbines - Part I: Rig Design, Instrumentation, and Experimental Methodology”)
Gallagher discloses a turbofan comprising a low-pressure turbine having at least four stages.
Simonassi teaches that at least one of the four stages having a transonic airfoil cascade and wherein the last downstream airfoil cascade is a transonic airfoil cascade.
The closest prior art fails to disclose or suggest that at least one of the airfoil cascades upstream from the downstream airfoil cascades is not transonic.
Claims 17-29 and 31-34 depend upon claim 16 and so are allowable.
Regarding claim 36:
Closest prior art: Gallagher et al. (US 9,909,505), Simonassi et al. (“An Experimental Test Case for Transonic Low-Pressure Turbines - Part I: Rig Design, Instrumentation, and Experimental Methodology”), and Kuhne (US 6,682,301)
Gallagher discloses a turbofan engine comprising: a low-pressure turbine having at least four stages.
Simonassi teaches at least one of the four stages having a transonic airfoil cascade.
Kuhne teaches a transonic airfoil of the transonic airfoil cascade having a suction side surface including a linear portion having a linear profile when viewed in a sectional plane of the airfoil.
The closest prior art fails to disclose or suggest that the linear profile in the sectional plane of the airfoil extending radially over at least 10% of a radial length of the transonic airfoil.
Regarding claim 37:
Closest prior art: Gallagher et al. (US 9,909,505), Simonassi et al. (“An Experimental Test Case for Transonic Low-Pressure Turbines - Part I: Rig Design, Instrumentation, and Experimental Methodology”), and Kuhne (US 6,682,301)
Gallagher discloses a turbofan engine comprising: a low-pressure turbine having at least four stages.
Simonassi teaches at least one of the four stages having a transonic airfoil cascade.
Kuhne teaches a transonic airfoil of the transonic airfoil cascade having a suction side surface including a linear portion having a linear profile when viewed in a sectional plane of the airfoil.
The closest prior art fails to disclose or suggest that the linear profile having a curvature when viewed in the sectional plane of the airfoil, the curvature deviating from a linear shape by at most 5%.
Regarding claim 38:
Closest prior art: Gallagher et al. (US 9,909,505), Simonassi et al. (“An Experimental Test Case for Transonic Low-Pressure Turbines - Part I: Rig Design, Instrumentation, and Experimental Methodology”), and Kuhne (US 6,682,301)
Gallagher discloses a turbofan engine comprising: a low-pressure turbine having at least four stages.
Simonassi teaches at least one of the four stages having a transonic airfoil cascade.
Kuhne teaches a transonic airfoil of the transonic airfoil cascade having a suction side surface including a linear portion having a linear profile when viewed in a sectional plane of the airfoil.
The closest prior art fails to disclose or suggest a plurality of transonic airfoil cascades each having a respective transonic airfoil having a respective linear portion, wherein a respective total area of the respective linear portion increases from each of the plurality of airfoil cascades to a next airfoil cascade of the plurality of airfoil cascades in the downstream direction.
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.
Contact Information
Any inquiry concerning this communication or earlier communications from the examiner should be directed to DANIELLE M CHRISTENSEN whose telephone number is (571)270-3275. The examiner can normally be reached M-F 9-5 PM.
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/DMC/Examiner, Art Unit 3745
/COURTNEY D HEINLE/Supervisory Patent Examiner, Art Unit 3745