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 .
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.
Response to Amendment
Applicant’s amendment filed on 24 July 2025 has been entered. Claims 1, 5, 7, 15, and 18 are amended. Claims 11-13 have been canceled. Claims 1-10 and 14-21 are pending. The amended claims and arguments have overcome each and every objection set forth in the previous office action. Therefore, the previous objection is hereby withdrawn.
Applicant’s arguments with respect to the rejection(s) of Claims 1, 2, 4-7, 9-12, and 14-18 stand rejected under 35 U.S.C. § 103 as allegedly being unpatentable over U.S. 2018/0363554 ("Kroger") and U.S. 2010/0080697 ("Wojno") 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Therefore, the rejection has been withdrawn.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 Heeter et al. (US 20230175408).
Applicant’s arguments with respect to the rejection(s) above have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
Amended claim 1 is equivalent to original claim 12. Therefore this rejection is made non-final.
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.
The factual inquiries set forth in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), that are applied for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claims 1, 2, 4-7, 9, 10, and 14-18 are rejected under 35 U.S.C. 103 as being unpatentable over Kroger et al. (hereafter Kroger – US 20180363554) in view of Wojno et al. (hereafter Wojno – US 20100080697), and further in view of Heeter et al. (hereafter Heeter – US 20230175408).
Claim 1 recites “a turbofan engine.” Kroger teaches such a turbofan engine, as will be shown.
Kroger teaches (Figs. 1-11) a turbofan engine defining an axial direction and a longitudinal centerline along the axial direction, the turbofan engine comprising:
a fan section (14) having a fan (38), the fan comprising a plurality of fan blades (40);
a turbomachine (16) drivingly coupled to the fan, the turbomachine comprising an outer casing (18);
an outer nacelle (50) surrounding the fan and at least a portion of the turbomachine;
an outlet guide vane (55) extending between the turbomachine and the outer nacelle at a location downstream of the plurality of fan blades, the outlet guide vane defining a base and a tip (see Fig. 2); and
an inlet pre-swirl feature (100) attached to or integrated into the outer nacelle at a location upstream of the plurality of fan blades (see Fig. 1).
However, Kroger does not teach the outlet guide vane being forward swept from the base to the tip, wherein the outer nacelle comprises an outer attachment groove located at a trailing edge of the outlet guide vane and the turbomachine comprises an inner attachment groove located at the trailing edge of the outlet guide vane, and wherein the inner attachment groove is located aft of the outer attachment groove.
Wojno teaches (Figs. 1-8) a turbofan engine comprising an outlet guide vane (70) being forward swept from the base to the tip (see para. 0026).
Wojno teaches (para. 0026) the sweep of the guide vanes may be selected for aerodynamic, acoustic, and/or other benefits in terms of gas turbine engine performance, and therefore the amount of sweep of the guide vanes are a results effective variable dependent on desired performance. It would have been obvious to a person having ordinary skill in the art to apply the teachings of Wojno to optimize the amount of sweep of the guide vanes of Kroger through routine experimentation for a particular system to arrive at the outlet guide vane being forward swept from the base to the tip since the guide vane sweep is a recognized results effective variable. Doing so would result in improved aerodynamic and acoustic performance, as recognized by Wojno.
Heeter teaches (Figs. 1, 2) a turbofan engine comprising an outer nacelle comprises an outer attachment groove (see Fig. 2) located at a trailing edge of the outlet guide vane and the turbomachine comprises an inner attachment groove (148) located at the trailing edge of the outlet guide vane, and wherein the inner attachment groove is located aft of the outer attachment groove (see Fig. 2, a portion of the inner attachment groove at the trailing edge is aft of the outer attachment groove).
Heeter further teaches the attachment grooves receive and support the vanes (para. 0044).
Kroger merely teaches the outlet guide vane. A person having ordinary skill in the art applying the invention of Kroger would look to the prior art for suitable arrangements for attaching the outlet guide vane to the turbofan engine. Therefore, it would have been obvious for a person having ordinary skill in the art to apply the teachings of Heeter to the pump of Kroger to have the outer nacelle comprises an outer attachment groove located at a trailing edge of the outlet guide vane and the turbomachine comprises an inner attachment groove located at the trailing edge of the outlet guide vane, and wherein the inner attachment groove is located aft of the outer attachment groove, as both references and Applicant’s invention are directed to turbofan engines. Doing so would result in securing the vane, as recognized by Heeter.
Regarding Claim 2, Kroger, as modified with Wojno and Heeter in Claim 1 above, teaches (Kroger Figs. 1-11) the turbofan engine of claim 1, wherein the inlet pre-swirl feature is transitionable between a first angle with respect to the longitudinal centerline and a second angle with respect to the longitudinal centerline (by motor 140, see para. 0092, Fig. 7).
Regarding Claim 4, Kroger, as modified with Wojno and Heeter in Claim 1 above, teaches (Kroger Figs. 1-11) the turbofan engine of claim 1, wherein the inlet pre-swirl feature includes a leading edge (108), a trailing edge (110), and defines an opening at the trailing edge (170).
Regarding Claim 5, Kroger, as modified with Wojno and Heeter in Claim 1 above, teaches (Kroger Figs. 1-11) the turbofan engine of claim 3, further comprising: a controller (not shown but turbofan engines are known to be controlled with controllers having processors and memory) having one or more processors and one or more memory devices, the one or more memory devices storing instructions that when executed by the one or more processors cause the one or more processors to perform operations, in performing the operations, the one or more processors are configured to: receive an input indicating a condition of the plurality of fan blades (see para. 0105, reduce a wake); and in response to the condition of the plurality of fan blades, modulate a high pressure airflow through the opening at the trailing edge of the inlet pre-swirl feature during operation of the turbofan engine (see para. 0105, reduce a wake).
Regarding Claim 6, Kroger, as modified with Wojno and Heeter in Claim 1 above, teaches (Kroger Figs. 1-11) the turbofan engine of claim 1, wherein the inlet pre-swirl feature comprises a part-span inlet guide vane (para. 0074).
Regarding Claim 7, Kroger, as modified with Wojno and Heeter in Claim 1 above, teaches (Kroger Figs. 1-11) the turbofan engine of claim 6, wherein the part span inlet guide comprises an acoustic treatment (sculpted trailing edge 110 provides acoustic benefit, see para. 0101-0103 and Fig. 10).
Regarding Claim 9, Kroger, as modified with Wojno and Heeter in Claim 1 above, teaches (Kroger Figs. 1-11) the turbofan engine of claim 1, wherein the outlet guide vane defines an OGV reference line extending from an inner junction between the outlet guide vane and the turbomachine at a leading edge of the outlet guide vane and an outer junction between the outlet guide vane and the outer nacelle at the leading edge of the outlet guide vane, wherein the turbofan engine defines a radial reference line extending perpendicularly from the longitudinal centerline, and wherein an angle between the OGV reference line and the radial reference line is at least 5 degrees and less than or equal to 45 degrees (as discussed in rejection of claim 1 above, Wojno teaches the sweep angle is a results effective variable, it would be obvious to arrive at an angle between the OGV reference line and the radial reference line is at least 5 degrees and less than or equal to 45 degrees).
Regarding Claim 10, Kroger, as modified with Wojno and Heeter in Claim 1 above, teaches (Kroger Figs. 1-11) the turbofan engine of claim 9, wherein the angle between the OGV reference line and the radial reference line is at least 15 degrees and less than or equal to 35 degrees (as discussed in rejection of claim 1 above, Wojno teaches the sweep angle is a results effective variable, it would be obvious to arrive at an angle between the OGV reference line and the radial reference line is at least 15 degrees and less than or equal to 35 degrees).
Regarding Claim 14, Kroger, as modified with Wojno and Heeter in Claim 1 above, teaches (Kroger Figs. 1-11) the turbofan engine of claim 1, wherein the outlet guide vane is a first outlet guide vane of a plurality of outlet guide vanes, wherein each outlet guide vane of the plurality of outlet guide vanes defines a base and a tip and is forward swept from the base to the tip (there is a plurality of outlet guide vanes, see para. 0066).
Regarding Claim 15, Kroger, as modified with Wojno and Heeter in Claim 1 above, teaches (Kroger Figs. 1-11) the turbofan engine of claim 1, wherein the turbofan engine defines a bypass ratio equal to a ratio of a mass flowrate of airflow through the bypass passage to a mass flowrate of an airflow through an inlet of the turbomachine during cruise operations, wherein the bypass ratio is at least 5:1 and less than or equal to 20:1 (para. 0067).
Regarding Claim 16, Kroger, as modified with Wojno and Heeter in Claim 1 above, teaches (Kroger Figs. 1-11) the turbofan engine of claim 15.
Modified Kroger does not disclose the fan defines a fan diameter greater than or equal to four feet and less than or equal to 18 feet. Since Applicant has not disclosed that having the fan diameter range solves any stated problem or is for any particular purpose and it appears that the fan with the diameter of modified Kroger would perform equally well with a fan diameter in the specified range as claimed by Applicant, it would have been an obvious matter of design choice to modify the fan diameter to fall within the claimed range.
Regarding Claim 17, Kroger, as modified with Wojno and Heeter in Claim 1 above, teaches (Kroger Figs. 1-11) the turbofan engine of claim 15, wherein the fan is a single stage fan (para. 0064).
Regarding Claim 18, Kroger, as modified with Wojno and Heeter in Claim 1 above, teaches (Kroger Figs. 1-11) the turbofan engine of claim 1.
Modified Kroger does not disclose the turbofan defines a maximum rated thrust at sea level greater than or equal to 30,000 pounds and less than or equal to 150,000 pounds. Since Applicant has not disclosed that having the maximum rated thrust at sea level range solves any stated problem or is for any particular purpose and it appears that the fan with the maximum rated thrust at sea level of modified Kroger would perform equally well with a turbofan in the specified range as claimed by Applicant, it would have been an obvious matter of design choice to modify the maximum rated thrust at sea level to fall within the claimed range.
Claim 3 is rejected under 35 U.S.C. 103 as being unpatentable over Kroger in view of Wojno, and further in view of Heeter, and further in view of Giffin et al. (hereafter Giffin – US 4254619).
Regarding Claim 3, Kroger, as modified with Wojno and Heeter in Claim 1 above, teaches (Kroger Figs. 1-11) the turbofan engine of claim 1, wherein the inlet pre-swirl feature is a first inlet pre-swirl feature transitionable between a first angle with respect to the longitudinal centerline and a second angle with respect to the longitudinal centerline, wherein the turbofan engine further comprises: a second inlet pre-swirl feature located upstream of the plurality of fan blades, the second inlet pre-swirl feature attached to or integrated into the outer nacelle, wherein the second inlet pre-swirl feature is transitionable between a third angle with respect to the longitudinal centerline of the turbofan engine and a fourth angle with respect to the longitudinal centerline of the turbofan engine (there are a plurality of inlet pre-swirl features, each inlet pre-swirl feature being transitional between different angles, see para.0092).
However, Kroger does not teach the first inlet pre-swirl feature and the second inlet pre-swirl feature are independently controlled.
Giffin teaches (Figs. 1, 2, 5) a turbofan engine comprising inlet pre-swirl features wherein the inlet pre-swirl feature is a first inlet pre-swirl (61) feature transitionable between a first angle with respect to the longitudinal centerline and a second angle with respect to the longitudinal centerline (see col. 7, ln. 33-45), wherein the turbofan engine further comprises: a second inlet pre-swirl feature (62) located upstream of the plurality of fan blades, the second inlet pre-swirl feature attached to or integrated into the outer nacelle, wherein the second inlet pre-swirl feature is transitionable between a third angle with respect to the longitudinal centerline of the turbofan engine and a fourth angle with respect to the longitudinal centerline of the turbofan engine (see col. 7, ln. 33-45), the first inlet pre-swirl feature and the second inlet pre-swirl feature are independently controlled (see col. 7, ln. 33-45).
Giffin further teaches independently controlled inlet pre-swirl features are advantageous because airflow may be modulated in the bypass duct without any appreciable change to the airflow to the core. In this way the core will be able to meet horsepower demands without having to be overly sized in order to accommodate the modulations of the inlet guide vanes (col. 7, ln. 17-32)
It would have been obvious for a person having ordinary skill in the art to apply the teachings of Giffin to the turbofan engine of modified Kroger to have the first inlet pre-swirl feature and the second inlet pre-swirl feature are independently controlled, as both references and Applicant’s invention are directed to turbofan engine. Doing so would result in the core will be able to meet horsepower demands without having to be overly sized in order to accommodate the modulations of the inlet guide vanes, as recognized by Giffin.
Claims 8 and 13 are rejected under 35 U.S.C. 103 as being unpatentable over Kroger in view of Wojno, and further in view of Heeter, and further in view of Namgoong (US 20200123903).
Regarding Claim 8, Kroger, as modified with Wojno and Heeter in Claim 1 above, teaches (Kroger Figs. 1-11) the turbofan engine of claim 1, wherein the outer nacelle defines an inlet length (see Fig. 1), wherein the fan defines a fan diameter (see Fig. 1).
However, modified Kroger does not teach wherein a ratio of the inlet length to the fan diameter is less than or equal to 0.5.
Namgoong teaches (Fig. 1) a turbofan engine wherein the outer nacelle defines an inlet length (L), wherein the fan defines a fan diameter (D) wherein a ratio of the inlet length to the fan diameter is less than or equal to 0.5 (para. 0042).
Namgoong further teaches Such a relatively low L/D is desirable to reduce overall engine length and drag (col. 7, ln. 17-32)
It would have been obvious for a person having ordinary skill in the art to apply the teachings of Namgoong to the turbofan engine of modified Kroger to have the first inlet pre-swirl feature and the second inlet pre-swirl feature are independently controlled, as both references and Applicant’s invention are directed to turbofan engine. Doing so would result in reduced overall engine length and drag, as recognized by Namgoong.
Claims 19 and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Kroger in view of Wojno, and further in view of Heeter, and further in view of Mulcaire et al. (hereafter Mulcaire – US 20030031556).
Regarding Claim 19, Kroger, as modified with Wojno and Heeter in Claim 1 above, teaches (Kroger Figs. 1-11) the turbofan engine of claim 1.
However, modified Kroger does not teach an acoustic treatment attached to or integrated with the outer casing at a location aligned with the outlet guide vane along the longitudinal centerline.
Mulcaire teaches (Figs. 1-3) a turbofan comprising an acoustic treatment (40, see para. 0029) attached to or integrated with the outer casing (32) at a location aligned with the outlet guide vane along the longitudinal centerline (see Fig. 2).
Mulcaire further teaches the perforated skin and honeycomb structure form an acoustic treatment structure which provides additional noise reduction for the turbofan gas turbine engine.
It would have been obvious for a person having ordinary skill in the art to apply the teachings of Mulcaire to the turbofan engine of modified Kroger to have an acoustic treatment attached to or integrated with the outer casing at a location aligned with the outlet guide vane along the longitudinal centerline, as both references and Applicant’s invention are directed to turbofan engine. Doing so would result in additional noise reduction, as recognized by Mulcaire.
Regarding Claim 20, Kroger, as modified with Wojno and Heeter in Claim 1 above, teaches (Mulcaire Figs. 1-3) the turbofan engine of claim 19, wherein the outlet guide vane defines a junction with the outer casing at a leading edge of the outlet guide vane (See Fig. 2), and wherein the acoustic treatment is located at the junction, forward of the junction, or both (both, see Fig. 2).
Claim 21 is rejected under 35 U.S.C. 103 as being unpatentable over Kroger in view of Wojno, and further in view of Heeter, and further in view of Venter et al. (hereafter Venter – US 20210404387).
Regarding Claim 21, Kroger, as modified with Wojno and Heeter in Claim 1 above, teaches (Mulcaire Figs. 1-3) the turbofan engine of claim 1.
However, modified Kroger does not teach an accessory gearbox including a first portion positioned at least partially inward of the outer casing of the turbomachine in a radial direction extending perpendicularly to the longitudinal centerline and a second portion positioned at least partially outside the outer casing of the turbomachine in the radial direction.
Venter teaches (Figs. 2-3) a turbofan engine comprising an accessory gearbox 21 including a first portion 22 positioned at least partially inward of the outer casing of the turbomachine in a radial direction extending perpendicularly to the longitudinal centerline and a second portion (indicated at 21) positioned at least partially outside the outer casing 29 of the turbomachine in the radial direction (see Fig. 3).
Venter further teaches the accessory gearbox performs functions, and the aircraft accessory gearbox and the core accessory gearbox can each be arranged in the circumferential direction of the gas turbine engine in such a way that the core accessory gearbox and engine accessories operatively connected thereto are shielded against damage from components by the aircraft accessory gearbox and the aircraft accessories operatively connected thereto (para. 0057).
It would have been obvious for a person having ordinary skill in the art to apply the teachings of Venter to the turbofan engine of modified Kroger to have an accessory gearbox including a first portion positioned at least partially inward of the outer casing of the turbomachine in a radial direction extending perpendicularly to the longitudinal centerline and a second portion positioned at least partially outside the outer casing of the turbomachine in the radial direction, as both references and Applicant’s invention are directed to turbofan engines. Doing so would result in a protective arrangement, as recognized by Venter.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. See cited references.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ANDREW BUI whose telephone number is (571) 272-0685. The examiner can normally be reached on 7:30 AM - 4:30 PM.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Courtney Heinle can be reached on (571) 270-3508. The fax phone number for the organization where this application or proceeding is assigned is (571) 273-8300.
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/ANDREW THANH BUI/Examiner, Art Unit 3745
/COURTNEY D HEINLE/Supervisory Patent Examiner, Art Unit 3745