Prosecution Insights
Last updated: April 19, 2026
Application No. 18/739,584

NOSECONE FOR A DUCTED FAN GAS TURBINE ENGINE

Non-Final OA §102§103
Filed
Jun 11, 2024
Examiner
CLARK, RYAN C
Art Unit
3745
Tech Center
3700 — Mechanical Engineering & Manufacturing
Assignee
Rolls-Royce
OA Round
1 (Non-Final)
87%
Grant Probability
Favorable
1-2
OA Rounds
1y 12m
To Grant
96%
With Interview

Examiner Intelligence

Grants 87% — above average
87%
Career Allow Rate
231 granted / 265 resolved
+17.2% vs TC avg
Moderate +8% lift
Without
With
+8.5%
Interview Lift
resolved cases with interview
Fast prosecutor
1y 12m
Avg Prosecution
37 currently pending
Career history
302
Total Applications
across all art units

Statute-Specific Performance

§101
2.6%
-37.4% vs TC avg
§103
38.8%
-1.2% vs TC avg
§102
30.5%
-9.5% vs TC avg
§112
26.4%
-13.6% vs TC avg
Black line = Tech Center average estimate • Based on career data from 265 resolved cases

Office Action

§102 §103
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 . Claim Objections Claim 34 is objected to because of the following informalities: Claim 34 recites the limitation "the intermediate circumference" in lines 3-4. There is insufficient antecedent basis for this limitation in the claim. Appropriate correction is required. Claim Rejections - 35 USC § 102 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 21-24 and 30 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Campbell et al. (US Patent 3,794,444 A). PNG media_image1.png 262 346 media_image1.png Greyscale PNG media_image2.png 418 336 media_image2.png Greyscale Regarding claim 21, Campbell et al. discloses a nosecone (18, 20, 22, 24) for a ducted fan gas turbine engine (10), the nosecone comprising a body (18) with an outer surface (20) that tapers in axial extent from an apex (18) to a base of the body (shown as the transition between the nosecone and the row of fan blades (16), the apex defining a position of 0 percent axial extent (Fig. 1-2) and the base defining a position of 100 percent axial extent (Fig. 1-2), and in which the outer surface comprises a plurality of undulations (24) extending between a first location (The upstream end of 24 near 22) on the outer surface and a second location (The downstream end of 24 near the fan blades 16) on the outer surface, wherein the first location is positioned at from 0 to 50 percent of axial extent (Fig. 2) and the second location is positioned at from 85 to 100 percent of axial extent (Fig. 2). Regarding claim 22, Campbell et al. discloses all of claim 21 as above, in which the second location is positioned at less than 100 percent of axial extent and the base of the body is circular (Fig. 2, 20 is referred to as an actuate outer surface, and is therefore circular Col. 2:10-14). Regarding claim 23, Campbell et al. discloses all of claim 21 as above, in which the second location is positioned at 100 percent of axial extent and each of the plurality of undulations extend to the base of the body (Fig. 2, the undulations extend to 100 percent of the axial extent), whereby the base in undulated (Fig. 2). Regarding claim 24, Campbell et al. discloses all of claim 22 as above, in which the first location is positioned at from 5 to 25 percent (Fig. 1, Fig. 2 shows the position of the start of the undulations with a smooth non-undulated section between the apex 22 and the start) of axial extent, and the outer surface of the body comprises a smooth non-undulated section between the apex and the first location (Fig. 2). Regarding claim 28, Campbell et al. discloses all of claim 21 as above, in which each of the plurality of undulations extends circumferentially between a first peak (Fig. 3, shows a plurality of peaks and troughs) a second peak with a trough therebetween, wherein the first peak and the second peak both have a hyperbolic axial profile (Fig. 2 shows a hyperbolic profile for each feature 24; additionally, a sample hyperbola is displayed below) defined between the first location and the second location. PNG media_image3.png 347 750 media_image3.png Greyscale Regarding claim 29, Campbell et al. discloses all of claim 28 as above, in which the hyperbolic axial profile is defined by tangent lines having a deviation of up to 45 degrees from an axial profile of the trough (Fig. 2) at the respective first location and second location (Fig. 2, shows the axial profile of the features and they do not reach a 45 degree tangent line). Regarding claim 30, Campbell et al. discloses all of claim 21 as above, in which the undulations extend at least in part in an axial direction (Fig. 2). Regarding claim 31, Campbell et al. discloses a fan assembly (12) for a ducted fan gas turbine engine (10), comprising: a hub (14) with a plurality of fan blades (16) mounted thereto: a nosecone (18, 20, 22, 24) mounted to the hub comprising a body (18) with an outer surface (20) that tapers in axial extent from an apex (18) to a base of the body (shown as the transition between the nosecone and the row of fan blades (16)), the apex defining a position of 0 percent axial extent (Fig. 1-2) and the base defining a position of 100 percent axial extent (Fig. 1-2), and in which the outer surface comprises a plurality of undulations (24) extending between a first location (The upstream end of 24 near 22) on the outer surface and a second location (The downstream end of 24 near the fan blades 16) on the outer surface, wherein the first location is positioned at from 0 to 50 percent of axial extent (Fig. 2) and the second location is positioned at from 85 to 100 percent of axial extent (Fig. 2). Regarding claim 32, Campbell et al. discloses all of claim 31 as above, in which the second location is positioned at less than 100 percent of axial extent and the base of the body is circular (Fig. 2, 20 is referred to as an actuate outer surface, and is therefore circular Col. 2:10-14). Regarding claim 33, Campbell et al. discloses all of claim 31 as above, in which the first location is positioned at from 5 to 25 percent (Fig. 1, Fig. 2 shows the position of the start of the undulations with a smooth non-undulated section between the apex 22 and the start) of axial extent, and the outer surface of the body comprises a smooth non-undulated section between the apex and the first location (Fig. 2). Regarding claim 34, Campbell et al. discloses all of claim 31 as above, in which the outer surface of the body comprises a smooth, non-undulated section (22; Fig. 1-2) between the apex and an intermediate location (where the undulations begin in Fig. 1-2) on the outer surface, whereby the undulations are located between the intermediate circumferent and the base of the body. Regarding claim 38, Campbell et al. discloses all of claim 31 as above, in which each of the plurality of undulations extends circumferentially between a peak (24; Fig. 3) and a trough (20; Fig. 3) and a maximum different in radial extent between each peak and trough is up to 10 percent of a leading-edge span height of the plurality of fan blades (“it is preferred that each fin 24 be of small radial height relative to the diameter of the spinner” Col. 2:36-37). Regarding claim 39, Campbell et al. discloses all of claim 31 as above, in which the undulations extend at least in part in an axial direction (Fig. 2). Regarding claim 40, Campbell et al. discloses a nosecone (18, 20, 22, 24) for a ducted fan gas turbine engine (10), the nosecone comprising a body (18) with an outer surface (20) that tapers in axial extent from an apex (18) to a base of the body (shown as the transition between the nosecone and the row of fan blades (16), the apex defining a position of 0 percent axial extent (Fig. 1-2) and the base defining a position of 100 percent axial extent (Fig. 1-2), and in which the outer surface comprises a plurality of undulations (24) having an axial extend of 35 to 100 percent of the axial extend of the body (Fig. 2), and wherein each of the plurality of undulations extends circumferentially between a first peak (Fig. 3, shows a plurality of peaks and troughs) a second peak with a trough therebetween, wherein the first peak and the second peak both have a hyperbolic axial profile (Fig. 2 shows a hyperbolic profile for each feature 24; additionally, a sample hyperbola is displayed below) defined between the first location and the second location. PNG media_image3.png 347 750 media_image3.png Greyscale 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. Claims 25-26 and 36-37 are rejected under 35 U.S.C. 103 as being unpatentable over Campbell et al. (US Patent 3,794,444) in view of Otsuka (JP 2012026361 A). Regarding claim 25, Campbell et al. discloses all of claim 21 as above. However, Campbell et al. does not explicitly disclose, “in which the outer surface comprises from 8 to 48 undulations.” PNG media_image4.png 342 238 media_image4.png Greyscale Otsuka teaches, in the field of nosecoses with aerodynamic features, a nosecone with between 8 to 48 undulations (R1 and R2, Fig. 2; which corresponds to X and Y in Fig. 3). It would have been obvious to one of ordinary skill in the art before the effective filing date to modify the nosecone of Campbell et al. to have undulation between 8 and 48 as taught by Otsuka, as both references are in the same field of endeavor, and one of ordinary skill would appreciate that, “Moreover, in jet engine S1 of this embodiment, coating area | region R1 is provided for every front edge of the fan rotor blade 3a. For this reason, it is possible to prevent all the fan blades 3a from being blocked by ice.” [0045]). Regarding claim 26, Campbell et al. discloses all of claim 21 as above. However, Campbell et al. does not explicitly disclose, “in which the outer surface comprises from 10 to 44 undulations.” Otsuka teaches, in the field of nosecoses with aerodynamic features, a nosecone with between 10 to 44 undulations (R1 and R2, Fig. 2; which corresponds to X and Y in Fig. 3). It would have been obvious to one of ordinary skill in the art before the effective filing date to modify the nosecone of Campbell et al. to have undulation between 10 and 44 as taught by Otsuka, as both references are in the same field of endeavor, and one of ordinary skill would appreciate that, “Moreover, in jet engine S1 of this embodiment, coating area | region R1 is provided for every front edge of the fan rotor blade 3a. For this reason, it is possible to prevent all the fan blades 3a from being blocked by ice.” [0045]). Regarding claim 36, Campbell et al. discloses all of claim 31 as above. However, Campbell et al. does not explicitly disclose, “in which a ratio of the number of undulations on the nosecone to the number of fan blades is from 0.5 to 2” Otsuka teaches, in the field of nosecoses with aerodynamic features, in which a ratio of the number of undulations on the nosecone to the number of fan blades is from 0.5 to 2 (R1 and R2, Fig. 2; which corresponds to X and Y in Fig. 3). It would have been obvious to one of ordinary skill in the art before the effective filing date to modify the nosecone of Campbell et al. to have a ratio of the number of undulations on the nosecone to the number of fan blades be from 0.5 to 2 as taught by Otsuka, as both references are in the same field of endeavor, and one of ordinary skill would appreciate that, “Moreover, in jet engine S1 of this embodiment, coating area | region R1 is provided for every front edge of the fan rotor blade 3a. For this reason, it is possible to prevent all the fan blades 3a from being blocked by ice.” [0045]). Regarding claim 37, Campbell et al. discloses all of claim 31 as above. However, Campbell et al. does not explicitly disclose, “in which the number of fan blades is an integer multiple of the number of undulations on the outer surface of the nose cone.” Otsuka teaches, in the field of nosecoses with aerodynamic features, a nosecone an integer multiple of the number of undulations on the outer surface of the nose cone. (R1 and R2, Fig. 2; which corresponds to X and Y in Fig. 3). It would have been obvious to one of ordinary skill in the art before the effective filing date to modify the nosecone of Campbell et al. to have a number of fan blades be an integer multiple of the number of undulations on the outer surface of the nose cone as taught by Otsuka, as both references are in the same field of endeavor, and one of ordinary skill would appreciate that, “Moreover, in jet engine S1 of this embodiment, coating area | region R1 is provided for every front edge of the fan rotor blade 3a. For this reason, it is possible to prevent all the fan blades 3a from being blocked by ice.” [0045]). Allowable Subject Matter Claim 35 is 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 35, Campbell discloses all of claim 31 as above, in which each of the plurality of undulations extends circumferentially between a peak (Fig. 3, 24) and trough (Fig. 3, 20). However, neither Campbell nor any of the prior art of record teach or suggest, “and wherein a maximum diameter of the outer surface along each peak does not exceed a leading-edge hub diameter of the fan assembly.” Campbell discloses, “The radial height of each fin 24 may be maintained constant over the length of the fin or may be varied, depending upon number of fins employed and the spacing of adjacent fins. For aerodynamic reasons, however, it is preferred that each fin 24 be of small radial height relative to the diameter of the spinner” but does not explicitly disclose or teach “and wherein a maximum diameter of the outer surface along each peak does not exceed a leading-edge hub diameter of the fan assembly.” Conclusion The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. PNG media_image5.png 288 252 media_image5.png Greyscale WO 2022/200733 A1 discloses an inlet cone for an aircraft turbomachine. PNG media_image6.png 420 380 media_image6.png Greyscale US PGPUB 2016/0122034 A1 discloses an ice-shedding spinner for ram air turbine. PNG media_image7.png 662 566 media_image7.png Greyscale US PGPUB 2014/0186166 A1 discloses a hybrid continuous fiber chopper fiber polymer composite structure. PNG media_image8.png 720 440 media_image8.png Greyscale US Patent 7,739,865 B2 discloses a gas turbine engine inlet with noise reduction features. PNG media_image9.png 342 416 media_image9.png Greyscale US Patent 6,840,826 B2 discloses a water jet propulsion apparatus. Any inquiry concerning this communication or earlier communications from the examiner should be directed to RYAN C CLARK whose telephone number is (571)272-2871. The examiner can normally be reached Monday - Thursday 0730-1730, Alternate Fridays 0730-1630. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Courtney D Heinle can be reached at (571)-270-3508. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /RYAN C CLARK/ Examiner, Art Unit 3745
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Prosecution Timeline

Jun 11, 2024
Application Filed
Feb 19, 2026
Non-Final Rejection — §102, §103 (current)

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

1-2
Expected OA Rounds
87%
Grant Probability
96%
With Interview (+8.5%)
1y 12m
Median Time to Grant
Low
PTA Risk
Based on 265 resolved cases by this examiner. Grant probability derived from career allow rate.

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