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Claims 3, 4, 8, 9 have been withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected species, there being no allowable generic or linking claim. Applicant grouped claim 9 with the elected claims, but as it depends on a non-elected claim has also been withdrawn from further consideration.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 were received on 7/21/2026. These drawings are entered.
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 [see annotations, interpretation 1] 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 472 having an upper fan duct inlet 456 and a lower fan duct [for flow 460 477] 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; wherein the booster cowl is arranged to split an airflow in the upstream portion of the fan duct into an outer stream 456 flowing through the upper fan duct upper fan duct 472 and an inner stream 460 flowing in the lower fan duct, the outer stream becoming a first fan stream 472, wherein the core duct includes a core cowl 426 arranged to split the inner stream 460 flowing in the lower fan duct into a second fan stream [461 through 458] flowing toward [directionally] the upper fan duct 472 [in the direction toward 472, 465 for a broad interpretation; alternately, note flow 461 mixes with 462, 472 downstream of 465 and is also toward the upper fan duct] and a core stream 5 flowing into the core duct 5, wherein a leading edge of the booster cowl [to the right of 456] is disposed upstream of the core cowl 5 and a trailing edge 465 of the booster cowl is disposed downstream of a leading edge 459 of the core cowl.
Alternately, Giffin et al [2nd interpretation]… a booster 440 located downstream of the secondary fan and comprising a booster rotor blade 444 an inlet guide vane 454 or 452, a booster cowl [2nd interpretation, 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 [2nd interpretation] located outward of the booster rotor blade 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 464 having an upper fan duct inlet 454 and a lower fan duct [for flow 460 477] 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; wherein the booster cowl is arranged to split an airflow in the upstream portion of the fan duct into an outer stream 464 flowing through the upper fan duct inlet 454 and an inner stream 453 flowing in the lower fan duct, the outer stream becoming a first fan stream 472, wherein the core duct includes a core cowl 426 arranged to split the inner stream flowing in the lower fan duct 463 into a second fan stream [463 through 458] flowing toward the upper fan duct 464 [2nd interpretation] and a core stream 5 flowing into the core duct 5, wherein a leading edge of the booster cowl [2nd interpretation] is disposed upstream of the core cowl 5 and a trailing edge 458 of the booster cowl is disposed downstream of a leading edge 459 of the core cowl.
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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, wherein the booster cowl is arranged to split an airflow in the upstream portion of the fan duct into an outer stream flowing through the upper fan duct and an inner stream flowing in the lower fan duct, the outer stream becoming a first fan stream, wherein the core duct includes a core cowl arranged to split the inner stream flowing in the lower fan duct into a second fan stream flowing toward the upper fan duct and a core stream flowing into the core duct, wherein a leading edge of the booster cowl is disposed upstream of the core cowl and a trailing edge of the booster cowl is disposed downstream of a leading edge of the core cowl.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) [see interpretations 1 and 2 above in the anticipation section, these teachings are not repeated for conciseness.] .
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. Note that since Frantz and Zatorski don’t have the internal fan duct, they teach TPAR= unducted bypass ratio AB /AC (a range of 40 to 80 by Frantz)]. 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] and TPAR= unducted bypass ratio AB /AC as set forth above by these two references, when the third flow is zero. 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 / Zatorski 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.
Response to Arguments
Applicant's arguments filed 7/21/2026 have been fully considered but they are not persuasive.
Applicant’s arguments regarding the 112 rejection fail to persuade
“Applicant respectfully submits that the ‘airflow through the fan duct’ refers to the air flow downstream of the booster, the unified fan stream 634. Regarding Figures 6-9, the drawings show a bypass passage 522 and a third stream 524. The Office Action alleges that the bypass passage 522 is a ‘fan duct,’ but in the context of a ducted turbofan engine, the third stream 524 is the ‘airflow through the fan duct.’”
Applicant’s line of reasoning is not persuasive because applicant does not clearly define the flow passages / ducts sufficiently to determine what is a fan duct, upper fan duct and lower fan duct, and what is a bypass passage based on the different interpretations has made in Figs. 6-9 between unducted fans and ducted fan configurations. Applicant argues that 524 in Figs 6-9 is the fan duct. However, 522 has fan airflow through both 522 and 524 and so that undermines applicant’s argument that the claim is clear.
In response to applicant's argument that the examiner's conclusion of obviousness is based upon improper hindsight reasoning, it must be recognized that any judgment on obviousness is in a sense necessarily a reconstruction based upon hindsight reasoning. But so long as it takes into account only knowledge which was within the level of ordinary skill at the time the claimed invention was made, and does not include knowledge gleaned only from the applicant's disclosure, such a reconstruction is proper. See In re McLaughlin, 443 F.2d 1392, 170 USPQ 209 (CCPA 1971). The prior art applied demonstrate that the ranges for the different ratios are well known in the prior art and thus applicant’s arguments fail to persuade.
Applicant’s argument that
“The Office Action, page 17, alleged that "the bypass ratio may define all the flows...that bypass the core engine divided by the core flow." Applicant respectfully submits that this interpretation overlooks the specific definitions of the "thrust to power airflow ratio" (TPAR) and the "core bypass ratio" (CBR) recited in claim 1. Specifically, the cited references, while teaching several engine configurations, do not teach or suggest "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." At most, Simmons discloses a double-bypass engine, but Simmons' multiple, ducted bypasses do not teach or suggest "an airflow through a bypass passage over the turbomachine plus an airflow through the fan duct" in the configuration of the present application. The only way to reconstruct the TPAR is to look to Applicant's disclosure, find the specific factors and mathematical operations defining the TPAR, and then search for those factors in the prior art. For at least these reasons, the rejection of claim 1 should be withdrawn”
is completely misdirected. The Examiner’s statement italicized above was to help understand the teachings of the prior art, rather that any particular interpretation of the specific ratios TPAR and CBR recited in claim 1. TPAR and CBR were specifically treated by the art of record in the manner claimed by applicant and applicant’s argument completely ignores the treatment of these ranges by Frantz and Zatorski based on an arbitrary statement taken out of context. As Ostdiek et al already teach the claimed range of CBR, the question is whether TPAR is obvious. Frantz clearly teaches the unducted bypass ratio, which includes the bypass channel and airflow through the core engine and teaches Frantz et al teach the “bypass ratio” of an unducted fan may be between 40 to 80 in an unducted fan [¶ 0078]. As set forth previously by the Examiner:
“For this sum, it is understood that 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. Note that since Frantz and Zatorski don’t have the internal fan duct, they teach TPAR= unducted bypass ratio AB /AC (a range of 40 to 80 by Frantz)]. For applicant’s Fig. 11- 12 (&14) it is understood to be the massflow from the unducted fan + the massflow (respectively) / divided by the core flow [compare with applicant’s Figs. 1 which established the third flow in an analogous region].”
Again the range of 40 to 80 corresponds to the unducted bypass ratio [AB /AC - referenced by Zatorski and Frantz since they don’t have an internal fan duct] and they teach TPAR= unducted bypass ratio AB /AC (a range of 40 to 80 by Frantz)]. Restated, both the unducted bypass ratio / TPAR of 40 to 80 is well known in the art by Frantz (when the 3rd flow is zero). Since AB /AC = 40 to 80, then as long as the CBR is between 60 to 20 [as the claimed upper value of 100 for TPAR], then the claimed range of TPAR is met and clearly overlaps with the claimed TPAR range of 3.5-100. Ostdiek already teach the core bypass ratio (CBR) between 0.1 and 10 [specifically 0.1 to 1 or 0.01-2] is already referenced by Ostdiek in ¶ 0060 and thus when combined with the range of AB /AC = 40 to 80 is clearly within the claimed range of TPAR range of 3.5-100.
Concerning Simmons, applicant alleged:
“At most, Simmons discloses a double-bypass engine, but Simmons' multiple, ducted bypasses do not teach or suggest "an airflow through a bypass passage over the turbomachine plus an airflow through the fan duct" in the configuration of the present application.”
First, applicant does not claim an unducted fan. Applicant may be alluding to one via “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.” However, the application clearly discloses ducted fans in Figs. 7-9 and so undermines applicant’s argument, which does not appear to be excluded by the claims. Accordingly, the bypass passage over the turbomachine may be subject to a broad interpretation. This fairly reads on Simmons’s “first bypass” as it is over the turbomachine. The “second bypass” of Fig. 9 in Simmons was used to define applicant’s third stream [see annotations]. As set forth previously by the Examiner:
“Simmons paper teaches the core bypass ratio (CBR) corresponding to applicant’s third stream2 [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.”
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Applicant’s arguments are not persuasive, because the basic range applicant is claiming for TPAR is the sum of CBR [already taught by Ostdiek] + unducted bypass ratio [AB /AC - referenced by Zatorski and Frantz since they don’t have an internal fan duct]. As applicant’s range for TPAR is so large, the claimed range clearly overlaps with that already known in the art and is therefore unpatentable.
Applicant's amendment necessitated any 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 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
September 30, 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.
2 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.
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