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 without traverse of Species O(1) and subspecies I (Figs. 11, 20) in the reply filed on 3/02/2026 is acknowledged.
Claims 3, 4, 8, 9 have been withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected species, there being no allowable generic or linking claim. Applicant grouped claim 9 with the elected claims, but as it depends on a non-elected claim has also been withdrawn from further consideration. Election was made without traverse in the reply filed on 3/02/2026.
Drawings
The drawings are objected to as failing to comply with 37 CFR 1.84(p)(5) because they do not include the following reference sign(s) mentioned in the description: 634, 632, 630 [e.g. Fig. 11] and 1902 [Fig. 24] .
The drawings were received on 3/02/2026 & 8/06/2024. These drawings are entered.
Corrected drawing sheets in compliance with 37 CFR 1.121(d) are required in reply to the Office action to avoid abandonment of the application. Any amended replacement drawing sheet should include all of the figures appearing on the immediate prior version of the sheet, even if only one figure is being amended. The figure or figure number of an amended drawing should not be labeled as “amended.” If a drawing figure is to be canceled, the appropriate figure must be removed from the replacement sheet, and where necessary, the remaining figures must be renumbered and appropriate changes made to the brief description of the several views of the drawings for consistency. Additional replacement sheets may be necessary to show the renumbering of the remaining figures. Each drawing sheet submitted after the filing date of an application must be labeled in the top margin as either “Replacement Sheet” or “New Sheet” pursuant to 37 CFR 1.121(d). If the changes are not accepted by the examiner, the applicant will be notified and informed of any required corrective action in the next Office action. The objection to the drawings will not be held in abeyance.
Claim Rejections - 35 USC § 112
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, 2, 5-7, 10-19 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 1 “the gas turbine engine defining a thrust to power airflow ratio between 3.5 and 100 and a core bypass ratio between 0.1 and 10, wherein the thrust to power airflow ratio is a ratio of an airflow through a bypass passage over the turbomachine plus an airflow through the fan duct to an airflow through the core duct, and wherein the core bypass ratio is a ratio of the airflow through the fan duct to the airflow through the core duct” does not clearly set forth the invention. The claim further defined as upper fan duct, lower fan duct, and it is unclear where the airflow through the fan duct is in relationship to these fan ducts. In the specification the thrust to power airflow ratio between 3.5 and 100 is described in ¶ 0090 as using the “third stream” which corresponds to the “an airflow through the fan duct” in the claim. However, different embodiments define the third stream differently, in Fig. 1, ¶ 0067 defines the third stream as the fan flow path 172 through the fan duct. In Figs. 6-9, the third stream is defined as the passage 524, see e.g. Fig. 7, where 524 is different from the fan duct 522. Accordingly, the claim is unclear as to what type of fan flow configuration utilized, since the airflow through the fan duct for the claimed ratio may be deemed either that of the entire fan duct or a small portion of it. In other words for the elected species, it is unclear what “third stream” / portion of airflow through the fan duct is utilized for the claimed range. See also claim 16 for an analogous issue.
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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.
Claim(s) 20 is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Giffin et al (20110120082). Giffin et al teach A gas turbine engine comprising: a turbomachine comprising a compressor section 13, a combustion section 15, and a turbine section 16, 18 arranged in serial flow order, the turbomachine defining an engine inlet to an inlet duct, a fan duct inlet to a fan duct 472, 471, and a core inlet [for air 5, Fig. 5] to a core duct for 5; a primary fan 418 driven by the turbomachine; a secondary fan 422 located downstream of the primary fan within the inlet duct; and a booster 440 located downstream of the secondary fan and comprising a booster rotor blade 448, 444 an inlet guide vane 454 or 452, a booster cowl [leadlines for 445 and 465, see annotations], a strut [457 or below 407 - see annotations], and a stem [connected to actuator 453] extending through the booster cowl, the booster cowl [leadlines for 445 and 465] located outward of the booster rotor blade 448, 444 and within the fan duct at the fan duct inlet, the booster cowl separating an upstream portion of the fan duct into an upper fan duct having an upper fan duct inlet 456 and a lower fan duct [for flow 461, 477] having a lower fan duct inlet, the upper fan duct inlet and lower fan duct inlet collectively forming the fan duct inlet, the inlet guide vane 454 or 452 located forward of the booster rotor blade 448, 444, wherein the strut [see annotations] secures the booster cowl to the engine inlet.
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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) 1-2, 5-7, 10-20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Ostdiek et al (2021/0108597) in view of Giffin et al (2011/0120082) and Orlando et al (6763654) and Frantz et al (2023/0019277) and Simmons “Design and control of a variable geometry turbofan with an independently modulated third stream” [Simmons paper] and optionally Zatorski et al (2022/0069688) and Simmons “Design and control of a variable geometry turbofan with an independently modulated third stream” [Simmons paper] and optionally for claims 1, 2, 12, 17, 20 further in view of Dawson (4695220). Ostdiek et al teach (1) A gas turbine engine comprising: a turbomachine comprising a compressor section 27, a combustion section 28, and a turbine section 29, 50 arranged in serial flow order, the turbomachine defining an engine inlet 70 to an inlet duct, a fan duct inlet to a fan duct 73, and a core inlet to a core duct 72; a primary fan 21 driven by the turbomachine; a secondary fan 73 located downstream of the primary fan 21 within the inlet duct, the gas turbine engine defining a thrust to power airflow ratio and a core bypass ratio between 0.1 and 10 [¶ 0060], wherein the thrust to power airflow ratio is a ratio of an airflow through a bypass passage [about 77, e.g. downstream of 21] over the turbomachine 77 plus an airflow through the fan duct 73 to an airflow through the core duct 72, and wherein the core bypass ratio is a ratio of the airflow through the fan duct 73 to the airflow through the core duct 72; a booster located downstream of the secondary fan 73 and comprising a strut [see 42 from Fig. 5] (16) A method of operating a gas turbine engine, the method comprising: operating the gas turbine engine at a rated speed, wherein operating the gas turbine engine at the rated speed comprises operating the gas turbine engine to define a thrust to power airflow ratio and a core bypass ratio between 0.1 and 5, wherein the thrust to power airflow ratio is a ratio of an airflow through a bypass passage [about 77, e.g. downstream of 21] over a turbomachine of the gas turbine engine plus an airflow through a fan duct 73 to an airflow through a core duct 72, and wherein the core bypass ratio is a ratio of the airflow through the fan duct 73 to the airflow through the core duct 72, (20) A gas turbine engine comprising: a turbomachine comprising a compressor section 27, a combustion section 28, and a turbine section 29, 50 arranged in serial flow order, the turbomachine defining an engine inlet 70 to an inlet duct, a fan duct inlet to a fan duct 73, and a core inlet to a core duct 72; a primary fan 21 driven by the turbomachine; a secondary fan 73 located downstream of the primary fan 21 within the inlet duct; Ostdiek et al teach a booster located downstream of the secondary fan but located in the core passage rather than in a fan passage and thus do not teach (1) a booster … comprising an inlet guide vane, a booster cowl, a strut, and a stem extending through the booster cowl, the booster cowl separating an upstream portion of the fan duct into an upper fan duct having an upper fan duct inlet and a lower fan duct having a lower fan duct inlet, the upper fan duct inlet and lower fan duct inlet collectively forming the fan duct inlet, the inlet guide vane located forward of the booster rotor blade; wherein the strut secures the booster cowl to the engine inlet. (2) wherein the stem is spaced upstream from the strut. (5) a fan cowl, wherein the stem extends from the booster cowl to the fan cowl. (6) wherein the inlet guide vane is rotatable about a pitch axis to a specified pitch angle. (7) an outlet guide vane disposed upstream of the booster, wherein the outlet guide vane is rotatable about a pitch axis to a specified pitch angle. (10) a fan cowl, wherein the outlet guide vane extends from the fan cowl. (11) an actuator configured to rotate the inlet guide vane about a pitch axis. (12) wherein the inlet guide vane is rotatably fixed to the stem, the pitch axis extends through the stem, and the actuator is configured to rotate the stem. (13) wherein the inlet guide vane extends radially inward from the booster cowl through the engine inlet. (14) wherein the inlet guide vane is disposed inward of the booster cowl and extends inwardly from the booster cowl. (15) wherein the booster includes a trailing edge disposed in the fan duct. (16) rotating an inlet guide vane of a booster to direct an inner stream of air to a core cowl; and splitting the inner stream of air at the core cowl into a fan stream flowing into the fan duct and a core stream flowing into the core duct. (17) actuating an actuator to rotate a stem that is rotatably fixed to the inlet guide vane. (18) rotating an outlet guide vane disposed upstream of the booster to direct a stream of air to the booster. (19) splitting the stream of air at the booster into the inner stream of air flowing toward the core duct and an outer stream of air flowing toward the fan duct. (20) a booster comprising … an inlet guide vane, a booster cowl, a strut, and a stem extending through the booster cowl, the booster cowl separating an upstream portion of the fan duct into an upper fan duct having an upper fan duct inlet and a lower fan duct having a lower fan duct inlet, the upper fan duct inlet and lower fan duct inlet collectively forming the fan duct inlet, the inlet guide vane located forward of the booster rotor blade, wherein the strut secures the booster cowl to the engine inlet.Giffin et al teach: (1) a secondary fan 422 located downstream of the primary fan within the inlet duct; a booster 440 located downstream of the secondary fan and comprising a booster rotor blade 448, an inlet guide vane 452 [more narrowly, could also be 454 more broadly], a booster cowl [Interp 1) or 2)], a strut [see annotations], and a stem [see annotations, connected to actuator 453] extending through the booster cowl, the booster cowl separating an upstream portion of the fan duct into an upper fan duct having an upper fan duct inlet 456 and a lower fan duct [for flow 461, 477] having a lower fan duct inlet 458, the upper fan duct inlet and lower fan duct inlet collectively forming the fan duct inlet, the inlet guide vane 452 located forward of the booster rotor blade; wherein the strut secures the booster cowl to the engine inlet. (2) wherein the stem is spaced upstream from the strut [see annotations]. (5) a fan cowl [interpretation 1) 425 or 2) includes 465], wherein the stem extends from the booster cowl [interp 2) 447] to the fan cowl [interp. 2, includes 462 and 453]. (6) wherein the inlet guide vane 452 is rotatable about a pitch axis to a specified pitch angle. (7) an outlet guide vane 454 disposed upstream of the booster, wherein the outlet guide vane 454 is rotatable about a pitch axis [from actuator 455] to a specified pitch angle. (10) a fan cowl [interpretation 1) 425 or 2) includes 465], wherein the outlet guide vane 454 extends from the fan cowl [interp. 2)] . (11) an actuator 453 configured to rotate the inlet guide vane 452 about a pitch axis. (12) wherein the inlet guide vane 452 is rotatably fixed to the stem, the pitch axis extends through the stem, and the actuator 453 is configured to rotate the stem. (13) wherein the inlet guide vane 452 extends radially inward from the booster cowl through the engine inlet. (14) wherein the inlet guide vane 452 is disposed inward of the booster cowl and extends inwardly from the booster cowl. (15) wherein the booster includes a trailing edge 465 disposed in the fan duct. (16) rotating an inlet guide vane 452 or 454 of a booster 444 or 448 to direct an inner stream of air to a core cowl 426; and splitting the inner stream of air at the core cowl into a fan stream 461 flowing into the fan duct and a core stream 5 flowing into the core duct. (17) actuating an actuator 453 to rotate a stem [see annotations] that is rotatably fixed to the inlet guide vane. (18) rotating an outlet guide vane 454 [see annotations] disposed upstream of the booster to direct a stream of air to the booster. (19) splitting the stream of air at the booster into the inner stream of air 463 flowing toward the core duct 5 and an outer stream of air 461via 458 flowing toward the fan duct. (20) a booster located downstream of the secondary fan and comprising … an inlet guide vane 452, a booster cowl [Interp 1) or 2)] located outward of the booster rotor blade 448, 444 and within the fan duct at the fan duct inlet, the booster cowl separating an upstream portion of the fan duct into an upper fan duct having an upper fan duct inlet 456 and a lower fan duct [for flow 461, 477] having a lower fan duct inlet, the upper fan duct inlet and lower fan duct inlet collectively forming the fan duct inlet, the inlet guide vane 454 or 452 located forward of the booster rotor blade 448, 444, wherein the strut [see annotations] secures the booster cowl to the engine inlet. Griffin et al teach the booster compressor 440 with blocker door and inlet guide vane and stem allows for varying the flow through the fan ducts and enhancing the operability and control of the fan system [¶ 0020]. Orlando et al teach the equivalence of the booster 16 used in the inlet 39 of the core engine [Fig. 1, which is analogous to the arrangement of Ostdiek et al] to the booster 16 with booster cowl 17 at the fan inlet with fan flows 37, 137 and core inlet 135 flow [Fig. 2, which is analogous to the arrangement of Griffin et al]. Moreover, the arrangement of Fig. 2 provides an additional boost to the fan flow to provide additional thrust to the engine [col. 5, lines 30-50]. It would have been obvious to one of ordinary skill in the art to employ the booster, with booster cowl, flow blocker, booster rotor blade, core flow spitter strut, etc, i.e.
a booster located downstream of the secondary fan and comprising a booster rotor blade, an inlet guide vane, a booster cowl, a strut, and a stem extending through the booster cowl, the booster cowl separating an upstream portion of the fan duct into an upper fan duct having an upper fan duct inlet and a lower fan duct having a lower fan duct inlet, the upper fan duct inlet and lower fan duct inlet collectively forming the fan duct inlet, the inlet guide vane located forward of the booster rotor blade; wherein the strut secures the booster cowl to the engine inlet. (2) wherein the stem is spaced upstream from the strut. (5) a fan cowl, wherein the stem extends from the booster cowl to the fan cowl. (6) wherein the inlet guide vane is rotatable about a pitch axis to a specified pitch angle. (7) an outlet guide vane disposed upstream of the booster, wherein the outlet guide vane is rotatable about a pitch axis to a specified pitch angle. (10) a fan cowl, wherein the outlet guide vane extends from the fan cowl. (11) an actuator configured to rotate the inlet guide vane about a pitch axis. (12) wherein the inlet guide vane is rotatably fixed to the stem, the pitch axis extends through the stem, and the actuator is configured to rotate the stem. (13) wherein the inlet guide vane extends radially inward from the booster cowl through the engine inlet. (14) wherein the inlet guide vane is disposed inward of the booster cowl and extends inwardly from the booster cowl. (15) wherein the booster includes a trailing edge disposed in the fan duct. (16) rotating an inlet guide vane of a booster to direct an inner stream of air to a core cowl; and splitting the inner stream of air at the core cowl into a fan stream flowing into the fan duct and a core stream flowing into the core duct. (17) actuating an actuator to rotate a stem that is rotatably fixed to the inlet guide vane. (18) rotating an outlet guide vane disposed upstream of the booster to direct a stream of air to the booster. (19) splitting the stream of air at the booster into the inner stream of air flowing toward the core duct and an outer stream of air flowing toward the fan duct. (20) a booster located downstream of the secondary fan and comprising … an inlet guide vane, a booster cowl, a strut, and a stem extending through the booster cowl, the booster cowl separating an upstream portion of the fan duct into an upper fan duct having an upper fan duct inlet and a lower fan duct having a lower fan duct inlet, the upper fan duct inlet and lower fan duct inlet collectively forming the fan duct inlet, the inlet guide vane located forward of the booster rotor blade, wherein the strut secures the booster cowl to the engine inlet.
as taught by Griffin et al, as the booster compressor with inlet guide vane and/or blocker door allows for varying the flow through the fan ducts and enhancing the operability and control of the fan system [¶ 0020], where Orlando may be used to teach the equivalence of the booster in the core engine alone [Fig. 1 of Orlando, which is analogous to Ostdiek et al], and the booster in both the fan and core inlet [Fig. 2 of Orlando, which is analogous to Griffin et al], in order to provide additional fan flow which produces additional thrust..
As for the thrust to power airflow ratio between 3.5 and 100 and a core bypass ratio between 0.1 and 5 which are set forth in claims 1 and 13, the core bypass ratio between 0.1 and 5 is already referenced by Ostdiek in ¶ 0060. The thrust to power airflow ratio is a ratio of an airflow through a bypass passage over a turbomachine of the gas turbine engine plus an airflow through a fan duct to an airflow through a core duct is understood from ¶ 0090 of the specification to be:
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Restated, applicant’s TPAR in applicant’s Fig. 1 is the bypass ratio bypassing the core, when summing the massflow 194 from the unducted fan and the massflow from the fan duct 172 [3rd stream] / divided by the core flow. Note that this, by some definitions, is the “bypass ratio” since, the bypass ratio may define all the flows [unducted fan + fan duct flow] that bypass the core engine divided by the core flow. For this sum, it is understood that TPAR = core bypass ratio (CBR above) + unducted bypass ratio [AB /AC - referenced by Zatorski and Frantz since they don’t have an internal fan duct]. For applicant’s Fig. 11, 20, it is understood to be the massflow from the unducted fan + the massflow 626 or 1520 (respectively from Figs. 11, 20) / divided by the core flow 1522 [compare with applicant’s Figs. 7-9 which established the third flow in an analogous region]. Alternately, TPAR may be construed as unducted fan flow + fan flow 624 [Fig. 11] / core flow [using the designation of Fig. 1]. Zatorski et al teach the “bypass ratio” of an unducted fan is the unducted flow about the turbomachine 162 / core flow 160 [see ¶ 0028]. Frantz et al teach the “bypass ratio” of an unducted fan may be between 40 to 80 in an unducted fan [¶ 0078]. Accordingly, applicant’s TPAR, which when accounting for the claimed range of the core bypass ratio of Ostdiek et al [¶ 0060] range and unducted bypass ratio of Frantz et al / Zatorkski et al of between 40 to 80 [¶ 0078] overlaps the range of the claim [TPAR of 3.5-100]. Simmons paper teaches the core bypass ratio (CBR) corresponding to applicant’s third stream1 [Simmons’ second stream airflow] / core flow – which is BPR2 [see page x], these ranges are given e.g. on pages 38-39, Figs. 27-28 [from less than 1.5] and an Overall BPR, which appears to correspond to applicant’s TPAR as it encompasses all cold / bypass flows, includes a range above 3.5 and thus overlaps with applicant’s claimed range. It would have been obvious to one of ordinary skill in the art to employ applicant’s claimed range of TPAR, with the CBR of Ostdiek et al, as taught by Frantz / Zatorski as an obvious matter of using the workable ranges in the art. Simmons paper teaches the core bypass ratio (CBR) is the 3rd stream / core flow – which is BPR1 [see page x], these ranges are given e.g. on page 39, Fig. 28 [from 3.3 and below] and an Overall BPR, which appears to correspond to applicant’s TPAR, includes a range above 3.5 and thus overlaps with applicant’s claimed range. It would have been obvious to one of ordinary skill in the art to employ applicant’s claimed range of TPAR, as taught by Frantz / Zatorski as an obvious matter of using the workable ranges in the art. Alternately, it would have been obvious to one of ordinary skill in the art to employ applicant’s claimed range of TPAR and/or CBR, as taught by Simmons paper, as an obvious matter of using the workable ranges in the art.
The prior art, as applied above, already teach a stem for the inlet guide vane. Alternately, Dawson teaches a stem 28, 24 for the inlet guide vane 14, the inlet guide vane 14 is rotatable about a pitch axis to a specified pitch angle; wherein the inlet guide vane is rotatably fixed to the stem, the pitch axis extends through the stem, and the actuator is configured to rotate the stem; actuating an actuator to rotate a stem that is rotatably fixed to the inlet guide vane. It would have been obvious to utilize the a stem for the both the top and bottom of the inlet guide vanes of Griffin et al, as taught by Dawson, as a typical support / pivoting structure used to allow the variable inlet vane to be varied. The location of the stem would include the stem at each pivot location, i.e. extending through the booster cowl, to allow pivoting relative to the booster cowl.
Claim(s) 7, 10 is/are rejected under 35 U.S.C. 103 as being unpatentable over Ostdiek et al (2021/0108597) in view of Giffin et al (2011/0120082) and Orlando et al (6763654) and Frantz et al (2023/0019277) and Simmons “Design and control of a variable geometry turbofan with an independently modulated third stream” [Simmons paper] and optionally Zatorski et al (2022/0069688) and optionally for claims 1, 2, 12, 17, 20 further in view of Dawson (4695220), as applied above, and further in view of Sargisson (3841091). For an alternate treatment of claims 7, 10 from that previously applied, Giffin et al teach (7) an outlet guide vane 422 disposed upstream of the booster 440, (10) a fan cowl 425 [interp. 1], wherein the outlet guide vane 422 extends from the fan cowl 425. In this interpretation, Giffin et al [Interp. 1] do not teach wherein the outlet guide vane 422 is rotatable about a pitch axis to a specified pitch angle. Sargisson teaches an outlet guide vane 48, wherein the outlet guide vane is rotatable about a pitch axis to a specified pitch angle; a fan cowl 42, wherein the outlet guide vane 48 extends from the fan cowl 42 is typically done for the kind of outlet guide vane of Giffin et al, in order to control the angle for the flow from the fan [col. 3, lines 34-38]. It would have been obvious to one of ordinary skill in the art to make the outlet guide vane of Giffin et al, of the type that is wherein the outlet guide vane is rotatable about a pitch axis to a specified pitch angle for this type of fan outlet guide vane.
Contact Information
Any inquiry concerning this communication or earlier communications from the Examiner should be directed to TED KIM whose telephone number is 571-272-4829. The Examiner can be reached on regular business hours before 5:00 pm, Monday to Thursday and every other Friday.
The fax number for the organization where this application is assigned is 571-273-8300.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Devon Kramer, can be reached at 571-272-7118. Alternate inquiries to Technology Center 3700 can be made via 571-272-3700.
Information regarding the status of an application may be obtained from Patent Center https://www.uspto.gov/patents/apply/patent-center. Should you have questions on Patent Center, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). General inquiries can also be directed to the Inventors Assistance Center whose telephone number is 800-786-9199. Furthermore, a variety of online resources are available at https://www.uspto.gov/patent
/Ted Kim/
Telephone
571-272-4829
Primary Examiner
Fax
571-273-8300
April 17, 2026
1 Note Simmons paper uses the opposite designation as applicant. Simmons papers’ second stream corresponds to applicant’s third stream and Simmons papers’ third stream corresponds to flow through the bypass passage.
Prosecution Insights