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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 12/04/2025 has been entered.
Drawings
The drawings of 12/04/2025 are not approved as they do not conform with the requirements of 37 CFR “1.84 Standards for drawings.”
“(l) Character of lines, numbers, and letters. All drawings must be made by a process which will give them satisfactory reproduction characteristics. Every line, number, and letter must be durable, clean, black (except for color drawings), sufficiently dense and dark, and uniformly thick and well-defined. The weight of all lines and letters must be heavy enough to permit adequate reproduction. This requirement applies to all lines however fine, to shading, and to lines representing cut surfaces in sectional views. Lines and strokes of different thicknesses may be used in the same drawing where different thicknesses have a different meaning.”
The drawings are objected to because they are of poor line quality. 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.
As the drawings of 12/04/2025, have not been entered Figures 1, 2 should be designated by a legend such as --Prior Art-- because only that which is old is illustrated. See MPEP § 608.02(g).
Claim Rejections - 35 USC § 112
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
Claims 1, 3-9 and 12-14 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention.
Claim 1 requires “N variable pitch stator blades” – note that the only disclosure relating to variable pitch stator blades is for the unducted fan arrangement, e.g. illustrated in Fig. 2, 3B. Applicant did not possess “N variable pitch stator blades” in combination with the ducted fan arrangement, e.g. Figs. 3A, 9. Furthermore, applicant did not teach that the stator blades 40 in the turbine section are variable pitch [see ¶ 0043, 0065] nor that the stator blades 30 are variable pitch [¶ 0066]. Rather the specificaoin teaches each of vane / blades 32, 40 are taught rather as fixed, rather than variable pitch.
“[0066] At least one outlet guide vane 30 (called OGV in the rest of the description) is arranged in the secondary internal flow, upstream of the second exhaust nozzle 22, more precisely upstream of a trailing edge 222 of the second exhaust nozzle 22. The OGV is a fixed wheel arranged downstream of the fan 2, in the secondary internal flow of the ducted turbine engine 1, and allowing straightening the gyration of the flow. The number of blades 30 that the OGV wheel comprises can be comprised between 30 and 60. This example is not limiting, the invention being able to be applied to exhaust nozzles arranged downstream of the structural arms, themselves arranged downstream of the OGVs, or integrated with the OGVs. “
“[0043] In certain embodiments, the aeronautical propulsion system is an unducted double flow turbojet comprising an exhaust nozzle of which an inner surface delimits the internal air flow and of which an outer surface delimits an external air flow, a trailing edge of the exhaust nozzle comprising a plurality of chevrons, at least one first stator blade being arranged in the internal air flow upstream of the exhaust nozzle. It is understood that in the specific case, the first stator blade is a fixed TRF blade of the exhaust casing.”
[0065] At least one fixed blade of the exhaust casing 40 (called a TRF blade in the rest of the description) is arranged in the primary internal flow, upstream of the first exhaust nozzle 12, more precisely upstream of a trailing edge 122 of the first exhaust nozzle 12. The TRF is the last bladed wheel in the primary internal flow of the turbine engine 1, located downstream of the low–pressure turbine and allowing removing the high–temperature air originating in the combustion chamber and in the high/low pressure turbine stages. The number of TRF blades 40 is typically on the order of 10.”
Accordingly, applicant does not possess the limitations of claim 1 for the stator blades 40 in the turbine section being variable pitch, see e.g. claims 13, 14. Applicant furthermore does not possess the limitations of claim 1 in combination with claim 12, since that would appear to require both 30 and 40 to be variable pitch and applicant does not have possession of either of those being variable pitch, but rather were disclosed as fixed.
Claim 14 “the trailing edge of the exhaust nozzle comprising the at least one first pattern and the at least one second trailing edge pattern, the at least one first trailing edge pattern being arranged in such a manner that the angular range ΔΘ over which it extends includes the stator blade closest axially to the trailing edge, among the at least one first stator blade”. Applicant’s claim 14 conflicts with claim 1 which specifies each of the N stator blades being variable pitch. As claim 14 would change the angular range ΔΘ to that of the closest stator blade, including internal blade of claim 13, applicant does not have possession of the second blade being closer than the first stator blade which are already defined as on the pitch change axis.
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, 3-9 and 12-14 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.
The claims are generally narrative and indefinite, failing to conform with current U.S. practice. They appear to be a literal translation into English from a foreign document and are replete with grammatical and idiomatic errors.
Claim 1 requires: “the plurality of chevrons are protrusions with respect to reference plane,” and “the first trailing edge patterns being portions of the trailing edge not having a chevron, these portions being straight and comprised in a same reference plane.” In the first recitation, Applicant does not clearly define “reference plane” and which direction the protrusions are directed. Accordingly, applicant’s claims are unclear. Also, the recitation of “a same reference plane” does not clearly spell out the relationship with the previous recitation of “reference plane” and makes it unclear whether this is the same element or a different one.
Claim 12 “the aeronautical propulsion system being a ducted double flow turbojet comprising the at least one exhaust nozzle which is a first exhaust nozzle through which is ejected a first internal air flow and a second exhaust nozzle through which is ejected a second internal air flow, a trailing edge of each of the first and of the second exhaust nozzle comprising a plurality of chevrons, the plurality of chevrons are protrusions with respect to reference plane, N first stator blades including first stator blades arranged in the first internal air flow upstream of the first exhaust nozzle, and N second stator blades including second stator blades being arranged in the second internal air flow upstream of the first exhaust nozzle and of the second exhaust nozzle, the trailing edge of each of the first and second exhaust nozzle comprising the N first trailing edge patterns and the N second trailing edge patterns” is unclear.
Note that “N first stator blades including first stator blades arranged in the first internal air flow upstream of the first exhaust nozzle, and N second stator blades including second stator blades being arranged in the second internal air flow upstream of the first exhaust nozzle and of the second exhaust nozzle” is unclear whether N first stator blades and N second stator blades are both required from claim 1, with the angle relationship “each angular range ΔΘ including one of the N stator blades being centered on a main axis of the blade which is a pitch change axis of the stator blades, such that ΔΘmin < ΔΘ < ΔΘmax, where ΔΘmin = 360/(36*N) and ΔΘmax=360/(N+1), ΔΘmin, ΔΘ and ΔΘmax being expressed in degrees”. Restated, applicant does not clearly set forth the relationship between the N stator blades of claim 1 and the N first stator blades and N second stator blades of claim 12. Moreover, applicant does not make it clear which relationship N second trailing edge patterns of claim 1 has with the N first stator blades and N second stator blades. In other words, the claim does not clearly define relationship with claim 1 when claim 12 has two nozzles and two different sets of N stator blades (first, second).
Also for claim 13 “an exhaust nozzle of the least one exhaust nozzle” is unclear, as applicant already references “an exhaust nozzle” in claim 1. As applicant only disclosed a single exhaust nozzle and a single row of chevrons for the unducted fan configuration, it appears claim 13 should further clarify the relationship with claim 1, e.g.
–the exhaust nozzle being a single exhaust nozzle– rather than ““an exhaust nozzle of the least one exhaust nozzle”;
–the trailing edge of the exhaust nozzle comprising the plurality of chevrons–rather than
“a trailing edge of the exhaust nozzle comprising a plurality of chevrons”;
–said trailing edge– rather than “a trailing edge”
–the plurality of chevrons – rather than “a plurality of chevrons”, etc.
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, 3-5, 9, is/are rejected under 35 U.S.C. 103 as being unpatentable over Vassberg et al (2019/0128214) in view of any of Hall et al (2023/0066572) and in view of optionally1 either Mengle (2010/0257865) of the IDS or Tse (6640537). Vassberg et al teach An aeronautical propulsion system configured to receive at least one internal air flow, comprising N stator blades 50 [N =14 from Fig. 8], where N ≥ 2, distributed circumferentially around the central axis, at least one exhaust nozzle 32 through which is ejected the at least one internal air flow, extending around a central axis and being arranged downstream of the stator blades, a trailing edge of the exhaust nozzle comprising a plurality of chevrons 38 distributed circumferentially around the central axis, the plurality of chevrons are protrusions with respect to reference plane, said trailing edge comprising:- N [N=14 from Fig. 7B] first trailing edge patterns [as illustrated each chevron corresponds to a stator blade] each extending, in an azimuthal direction, over an angular range ΔΘ including one of the N stator blades, the first trailing edge patterns being portions of the trailing edge [e.g. chevron tips when chevron 38 is inline with stator blades 50] or being portions of the trailing edge not having a chevron, and - N second trailing edge patterns [e.g. space between chevrons tips, notches] distinct from the first trailing edge patterns and extending, in the azimuthal direction, over an angular range ΔΘ’ including none of the N stator blades [space between 50], the second trailing patterns being portions of the trailing edge comprising at least one chevron [e.g. notch between 38], and being, the number of first trailing edge patterns distinct from one another being comprised between 1 and N [equals N], each angular range ΔΘ including one of the N stator blades 50 being centered on a main axis of the blade, and being such that ΔΘmin < ΔΘ < ΔΘmax, where ΔΘmin = 360/(36*N) [N=14, ΔΘmin = 1⁰] and ΔΘmax=360/(N+1) [N=14, ΔΘmax = 32⁰], ΔΘmin, ΔΘ and ΔΘmax being expressed in degrees – note that since N is 14, the angular spacing between the 14 blades is 360⁰/14= 25.7⁰ and as ΔΘ is the angle including one of the N stator blades, the spacing 25.7⁰ between blades is less than ΔΘmax = 32⁰ which is the maximum allowed angle range for the stator blades to cover. Restated, this range is so broad that at least for the 14 blades situation, the claimed angle range will always be met because the maximum range of ΔΘmax times the number of blades would exceed the perimeter of the entire nozzle. (9) wherein S/C < 5 [appears to be in the claimed range in Fig. 9, alternately, it would have been obvious to one of ordinary skill in the art to employ this range, as an obvious matter of using the workable ranges in the art], where S is a distance between the trailing edge of the at least one stator blade 50 at a connection of the stator blade on a casing of the propulsion system and the point of the trailing edge of the exhaust nozzle closest to the stator blade in the direction of the central axis, and C is the chord of the stator blade measured at the connection. Vassberg et al teach each angular range ΔΘ including one of the N stator blades 50 being centered on a main axis of the blade but do not teach the N stator blades are variable pitch stator blades, the main axis of the blade which is a pitch change axis of the stator blades.. Hall et al teach N stator blades are variable pitch stator blades, the main axis of the blade which is a pitch change axis of the stator blades. each angular range ΔΘ including one of the N stator blades 30 being centered on a main axis of the blade 33 which is the pitch change axis when the stator blades are variable pitch stator blades 30. Hall et al teach making the stator blades as variable pitch stator blades allows one to
“vary a pressure downstream of the fan inlet, minimize intake flow distortion experienced by the inlet fan, reduce inlet fan vibratory response and/or improve fan operability margins [paragraph 0007]”
It would have been obvious to one of ordinary skill in the art to make the N stator blades of Vassberg et al, variable pitch stator blades which has the pitch change axis, in the manner taught by Hall et al, in order to “vary a pressure downstream of the fan inlet, minimize intake flow distortion experienced by the inlet fan, reduce inlet fan vibratory response and/or improve fan operability margins [paragraph 0007].”
Note Vassberg et al illustrate a single chevron per stator blade but teach the number of chevron peaks/valleys are integer multiples of the number of stator blades [see paragraph 0021]. In the Figs, the valley is aligned with the longitudinal line and when the stator is aligned with the longitudinal line in Fig. 8. Note that using numbers of integer multiples (e.g. 2, 3, 4, 5, etc.) would result in the there being multiple (e.g. 2, 3, 4, 5, respectively) peaks being the longitudinal lines, e.g. for 3 peaks, there are 3 chevron peaks between lines - for 5 peaks, 5 chevron peaks between lines - for 4 peaks, 4 peaks between lines, etc. In such a situation, these chevrons may arbitrarily be grouped with the first trailing edge patterns aligned with the stator blades and the second trailing patterns between the stator blades. These numbers are variable based on the number of chevrons, e.g. 5 chevrons as the integer multiple, results in 5 chevrons of which one, two, three, or four may be in the first pattern and four, three, two, one, respectively may be in the second pattern. In such a case, the features of claim are met (4) wherein the second trailing edge pattern is a portion of the trailing edge comprising at least two chevrons. Vassberg et al do not necessarily teach (3) wherein the first trailing edge pattern and/or the second trailing edge pattern are not homothetic geometric patterns nor (5) wherein the at least one second trailing edge pattern comprises at least two chevrons with different amplitudes and/or widths and/or geometries. Mengle teach (5) wherein the at least one second trailing edge pattern comprises at least two chevrons with different amplitudes and/or widths and/or geometries [see Figs. 3, 4, 11C] and (3) wherein the first trailing edge pattern and/or the second trailing edge pattern are not homothetic geometric patterns [see Figs. 3, 4, 11C]; and that the differing distributions / geometries allows for tailoring the noise reduction including the direction and different acoustic frequencies [see paragraph 0005, 0007, 0009]. Alternately, Tse teaches (3) wherein the first trailing edge pattern and/or the second trailing edge pattern are not homothetic geometric patterns [see Fig. 1]; and (5) wherein the at least one first trailing edge pattern and/or the at least one second trailing edge pattern comprises at least two chevrons with different amplitudes and/or widths and/or geometries [see Fig. 1]. Tse teaches the irregular trailing edge with different sizes and shapes facilitate the mixing and noise reduction [see col. 6, lines 5-13]. It would have been obvious to one of ordinary skill in the art to employ (3) wherein the first trailing edge pattern and/or the second trailing edge pattern are not homothetic geometric patterns and (5) wherein the at least one second trailing edge pattern comprises at least two chevrons with different amplitudes and/or widths and/or geometries, in the manner taught by Mengle or Tse, as differing distributions / geometries allows for tailoring the noise reduction including the direction and different acoustic frequencies. Vassberg et al do not teach the first trailing edge patterns being portions of the trailing edge not having a chevron, these portions being straight and comprised in a same reference plane. Vassberg et al’s chevrons are generally triangular in shape. Mengle teaches the chevron shape be trapezoidal or rectangular [¶ 0004] as equivalent to triangular in shape, which would appear to meet the requirement that these portions being straight and comprised in a same reference plane. Young teaches the first trailing edge patterns 10 being portions of the trailing edge [projection] not having a chevron, these portions 10 being straight and comprised in a same reference plane. Alternately, the base of the notches between projections 10 are regarded as the “chevron”. It would have been obvious to one of ordinary skill in the art to employ the first trailing edge patterns being portions of the trailing edge not having a chevron, these portions being straight and comprised in a same reference plane, to replace the chevrons of Vassberg et al, as taught by Mengle and Young, as using rectangular or trapezoidal projections with straight portions of the trailing edge are regarded as equivalent to using triangular shapes by Mengle.
Claim(s) 8 is/are rejected under 35 U.S.C. 103 as being unpatentable over any of the above prior art and further in view of Ardoin (3,215,172). The above prior art do not teach (8) comprising (i) an upstream portion of the exhaust nozzle and an annular cowling configured to be detachably attached to the upstream portion, a downstream end of the annular cowling comprising the plurality of chevrons. Ardoin teaches (8) comprising (i) an upstream portion 12 of the exhaust nozzle, and an annular cowling 15 configured to be detachably attached 13, 14 to the upstream portion 12, a downstream end of the annular cowling comprising the plurality of chevrons 17. Ardoin teaches this configuration allows the noise suppressor to be
“quickly and easily installed on or detached from existing engines or alternatively may be constructed as an integral part of an engine [lines bridging col. 1-col. 2].”
It would have been obvious to employ (i) an upstream portion of the exhaust nozzle, and an annular cowling configured to be detachably attached to the upstream portion, a downstream end of the annular cowling comprising the plurality of chevrons, in the manner taught by Ardoin, to attach the chevrons to the upstream portion, (i) an upstream portion, and an annular cowling configured to be detachably attached to the upstream portion, a downstream end of the annular cowling comprising the plurality of chevrons, as it facilitates quickly and easily installation or detachment from existing engines, which facilitates repair.
Claim(s) 6 is/are rejected under 35 U.S.C. 103 as being unpatentable over any of the above prior art and further in view of Moore et al (2011/0167785). The prior art do not teach (6) the at least one first trailing edge pattern and/or the at least one second trailing edge pattern comprise two chevrons so as to form at least one interval between said at least two chevrons, the at least one interval is filled at least partially with a porous material. Moore et al teach trailing edge pattern comprise two chevrons so as to form at least one interval between said at least two chevrons, the at least one interval is filled at least partially with a porous material 137[Fig. 9-12C]. Moore et al teach the acoustic
“[0079] The primary role of the forward/upstream part of the acoustic lining 137 on the outer wall of the mixer duct shell 134' will be targeting the same sound source(s) that the acoustic lining on the fan duct inner wall 36a', as shown in FIG. 18. Because the annular fan "duct" terminates at completion of the fan-nozzle trailing edge (or Chevrons, if they are used) the acoustic lining 137 on the outer wall of the mixer duct shell 134' can either be unchanged relative to the rest to save costs. Alternatively, the acoustic lining 137 downstream of the fan nozzle exit on the outer surface of the mixer duct shell 134' can be altered to target broadband noise through use of the same bulk absorbing material used on the inner wall of the mixer duct shell 134', and the same face sheet used on the forward part of the outer shell, but with a relatively high level of porosity (25% to 40%). “
Note that the different parts of Fig. 12 refer to acoustic liner and the acoustic lining are present in the context of the chevrons B1 in Fig. 12C, including between adjacent chevrons as the acoustic lining extends to the fan trailing edge/chevrons according to the excerpted text. It would have been obvious to one of ordinary skill in the art to employ porous material / acoustic lining, i.e. at least one first trailing edge pattern and/or the at least one second trailing edge pattern comprise two chevrons so as to form at least one interval between said at least two chevrons, the at least one interval is filled at least partially with a porous material, in the manner taught by Moore et al, to absorb acoustic energy / reduce engine noise.
Claim(s) 7 is/are rejected under 35 U.S.C. 103 as being unpatentable over any of the above prior art and further in view of Webster (2013/0017065). The prior art do not teach (7) wherein, the at least one second trailing edge pattern comprise two chevrons so as to form at least one interval between said at least two chevrons, the at least one interval is filled at least partially with a plurality of metal slats. Webster teach (7) wherein, the at least one second trailing edge pattern comprise two chevrons 16, 18 so as to form at least one interval between said at least two chevrons, the at least one interval is filled at least partially with a plurality of metal slats 48, 50 [Fig. 17]. Webster teaches this arrangement facilitates enhancing the mixing and provides a rigid structure to the nozzle. While not specifically mentioning the slats are of metal, the adjacent chevrons 16, 18 are made of alloy, which is by definition a metal, and thus the materials at that location between the chevrons are understood to be metal / metal alloy. It would have been obvious to one of ordinary skill in the art to make the at least one first trailing edge pattern and/or the at least one second trailing edge pattern comprise two chevrons so as to form at least one interval between said at least two chevrons, the at least one interval is filled at least partially with a plurality of metal slats, in the manner taught by Webster, in order to facilitate enhance the mixing and still provide a rigid structure to the nozzle, and further it would have been obvious that making the slats metal, is the typical material used in that location, as evidenced by the adjacent materials being of metal alloy.
Claim(s) 12 is/are rejected under 35 U.S.C. 103 as being unpatentable over Vassberg et al (2019/0128214) in view of Hall et al (2023/0066572) and for claims 3, 5 further in view of either Mengle (2010/0257865) of the IDS or Tse (6640537), as applied above, and further in view of Mengle (2010/0257865) and Rolt (2016/0010589). Vassberg et al teach [Fig. 2] further (12) the aeronautical propulsion system being a ducted double flow turbojet comprising the at least one exhaust nozzle which is a first exhaust nozzle 20 through which is ejected a first internal air flow and a second exhaust nozzle 32 through which is ejected a second internal air flow, a trailing edge of each of the second exhaust nozzle 32 comprising a plurality of chevrons 40, the plurality of chevrons are protrusions with respect to reference plane, and the N second stator blades including second stator blades 50 being arranged in the second internal air flow upstream of the first exhaust nozzle and of the second exhaust nozzle, Vassberg does not teach the first exhaust nozzle with a plurality of chevrons and N first stator blades including first stator blades arranged in the first internal air flow upstream of the first exhaust nozzle, the trailing edge of each of the first and second exhaust nozzle comprising the N first trailing edge patterns and the N second trailing edge patterns. Rolt [Fig. 4] teaches the first nozzle has N first stator blades including first stator blades 83 arranged in the first internal air flow upstream of the first exhaust. Mengle teaches both the first and second exhaust nozzle 243, 233 comprising a plurality of chevrons 245, 235 and the trailing edge of each of the first and second exhaust nozzle comprising the N first trailing edge patterns and the N second trailing edge patterns. Note that the claim 8 does states a relationship between these first and second trailing edge pattern and those recited in claim 1; however, applicant does not have possession of the first stator blades being variable pitch – as required in claim 1. It would have been obvious to one of ordinary skill in the art to employ N first stator blades including first stator blades arranged in the first internal air flow upstream of the first exhaust nozzle, in the manner taught by Rolt, as a typical configuration used in the art for guiding the flow from the turbine. It would further have been obvious to make the trailing edge of each of the first and second exhaust nozzle comprising the N first trailing edge patterns and the N second trailing edge patterns, as taught by Mengle, in order to reduce the noise. As Vassberg teaches how to determine the stator position and relative chevron position for the second nozzle, it would have been obvious to employ a similar relationship to the first nozzle, as analogous aerodynamic considerations exist between the two nozzles. It would have been obvious to make the first exhaust nozzle use a plurality of chevrons and the first exhaust nozzle with at least one first trailing edge pattern and at least one second trailing edge pattern, as an obvious matter of extending the teachings of Vassberg relative to the N stator blades and chevrons to the first nozzle, as analogous aerodynamic considerations exist between the two nozzles.
Claim(s) 13, 14 is/are rejected under 35 U.S.C. 103 as being unpatentable over Vassberg et al (2019/0128214) in view of Hall et al (2023/0066572) and in view of optionally either Mengle (2010/0257865) of the IDS or Tse (6640537) and further in view of Ostdiek et al (2021/0108597) and further in view of either Negulescu (2016/0347463) or Wright (3632224). Vassberg et al do not teach (13) the aeronautical propulsion system being an unducted double flow turbojet comprising an exhaust nozzle of the at least one exhaust nozzle, of which an inner surface delimits the internal air flow and of which an outer surface delimits an external air flow, a trailing edge of the exhaust nozzle comprising a plurality of chevrons, the plurality of chevrons are protrusions with respect to reference lane, at least one first stator blade of the N variable stator pitch blades being arranged in the internal air flow downstream of a low pressure turbine and upstream of the exhaust nozzle; nor (14) the trailing edge of the exhaust nozzle comprising the trailing edge of the exhaust nozzle comprising the at least one first pattern and the at least one second trailing edge pattern, the at least one first trailing edge pattern being arranged in such a manner that the angular range ΔΘ over which it extends includes the stator blade closest axially to the trailing edge, among the at least one first stator blade and the at least one second stator blade. Ostdiek et al teach (13) the aeronautical propulsion system being an unducted double flow turbojet comprising an exhaust nozzle 77, of which an inner surface delimits the internal air flow 70 and of which an outer surface 77 delimits an external air flow, a trailing edge of the exhaust nozzle comprising a plurality of chevrons 78 [see paragraph 0058], the plurality of chevrons are protrusions with respect to reference plane, at least one first stator blade [unlabeled, vane in section 80] being arranged in the internal air flow downstream of a low pressure turbine 50 and upstream of the exhaust nozzle 79; and (14) at least one second stator blade 31 arranged in the external air flow upstream of the exhaust nozzle, the trailing edge of the exhaust nozzle 77 comprising [chevrons] with at least one first pattern and at least one second trailing edge pattern, the at least one first trailing edge pattern being arranged in such a manner that the angular range ΔΘ over which it extends includes the stator blade closest axially to the trailing edge 78, among the at least one first stator blade and the at least one second stator blade. Ostdiek et al teach the equivalence between using a ducted turbojet [Fig. 10] with a unducted turbojet [Fig. 5]; see also paragraph 0002. It would have been obvious to one of ordinary skill in the art to apply the teachings of Vassberg to the unducted turbojet of Ostdiek, i.e. to employ (13) the aeronautical propulsion system being an unducted double flow turbojet comprising an exhaust nozzle of the at least one exhaust nozzle, of which an inner surface delimits the internal air flow and of which an outer surface delimits an external air flow, a trailing edge of the exhaust nozzle comprising a plurality of chevrons, the plurality of chevrons are protrusions with respect to reference plane, at least one first stator blade being arranged in the internal air flow downstream of a low pressure turbine and upstream of the exhaust nozzle; (14) the trailing edge of the exhaust nozzle comprising the at least one first pattern and the at least one second trailing edge pattern, the at least one first trailing edge pattern being arranged in such a manner that the angular range ΔΘ over which it extends includes the stator blade closest axially to the trailing edge, among the at least one first stator blade, in order to align the stators with the chevrons of the prior art in an engine type typically utilized in the art and regarded by Ostdiek et al as an equivalent engine type. As noted above, at least one first stator blade of the N variable stator pitch blades [is new matter] being arranged in the internal air flow downstream of a low pressure turbine and upstream of the exhaust nozzle. For this limitation, Wright teaches at least one first stator blade 34 of the N variable stator pitch blades 34 being arranged in the internal air flow downstream of a low pressure turbine 22 and upstream of the exhaust nozzle 28 which controls the flow output from the turbine through the nozzle. Negulescu teaches at least one first stator blade of the N variable stator pitch blades 18 being arranged in the internal air flow downstream of a low pressure turbine 12 and upstream of the exhaust nozzle13, which controls the flow output from the turbine through the nozzle. It would have been obvious to one of ordinary skill in the art to make the at least one first stator blade, of the N variable stator pitch blades being arranged in the internal air flow downstream of a low pressure turbine and upstream of the exhaust nozzle, as taught by either Wright or Negulescu, in order to control the flow output from the turbine through the exhaust nozzle.
Response to Arguments
Applicant's arguments filed 12/04/2025 have been fully considered but they are not persuasive.
Applicant’s argument that
“With respect to claim 1, the Office Action states that Applicant does not possess "N Variable pitch stator blades" in combination with the ducted fan arrangement. (Office Action at 4.) The Specification expressly discloses that the invention applies generally to all aeronautical propulsion systems, including but not limited to UHBR ducted engines and ducted variable-pitch fan (VPF) engines. Paragraph [0003] of the Specification identifies "Variable-Pitch Fan (VPF): ducted turbojet with a variable-pitch fan" as one of the architectures to which the invention applies. The Specification repeatedly and explicitly states that the exhaust-nozzle/chevron pattern invention is applicable to both ducted and unducted architectures (e.g., "[t]his example is not limiting, the invention being able to be applied ..."). (Specification at [0063]-[0064].) The disclosure of variable-pitch stator blades in the unducted USF configuration (Specification at [0069].) does not limit the invention; rather, it demonstrates that variable-pitch stators are within the contemplated set of upstream stators whose wakes and flow interactions motivate the claimed azimuthally-positioned trailing-edge patterns. Nothing in the Specification restricts variable-pitch stator blades to unducted engines.”
In rebuttal, the specification specifically teaches that the stator blades of
Applicant did not possess “N variable pitch stator blades” in combination with the ducted fan arrangement, e.g. Figs. 3A, 9. Furthermore, applicant did not teach that the stator blades 40 in the turbine section are variable pitch [see ¶ 0043, 0065] nor that the stator blades 30 are variable pitch [¶ 0066]. Rather, applicant’s specification teaches each of stator vane / blades 32, 40 are taught rather are fixed, rather than variable pitch.
“[0066] At least one outlet guide vane 30 (called OGV in the rest of the description) is arranged in the secondary internal flow, upstream of the second exhaust nozzle 22, more precisely upstream of a trailing edge 222 of the second exhaust nozzle 22. The OGV is a fixed wheel arranged downstream of the fan 2, in the secondary internal flow of the ducted turbine engine 1, and allowing straightening the gyration of the flow. The number of blades 30 that the OGV wheel comprises can be comprised between 30 and 60. This example is not limiting, the invention being able to be applied to exhaust nozzles arranged downstream of the structural arms, themselves arranged downstream of the OGVs, or integrated with the OGVs. “
“[0043] In certain embodiments, the aeronautical propulsion system is an unducted double flow turbojet comprising an exhaust nozzle of which an inner surface delimits the internal air flow and of which an outer surface delimits an external air flow, a trailing edge of the exhaust nozzle comprising a plurality of chevrons, at least one first stator blade being arranged in the internal air flow upstream of the exhaust nozzle. It is understood that in the specific case, the first stator blade is a fixed TRF blade of the exhaust casing.”
[0065] At least one fixed blade of the exhaust casing 40 (called a TRF blade in the rest of the description) is arranged in the primary internal flow, upstream of the first exhaust nozzle 12, more precisely upstream of a trailing edge 122 of the first exhaust nozzle 12. The TRF is the last bladed wheel in the primary internal flow of the turbine engine 1, located downstream of the low–pressure turbine and allowing removing the high–temperature air originating in the combustion chamber and in the high/low pressure turbine stages. The number of TRF blades 40 is typically on the order of 10.”
Accordingly, applicant does not possess the limitations of claim 1 for the stator blades 40 in the turbine section being variable pitch, see e.g. claims 13, 14. Applicant furthermore does not possess the limitations of claim 1 for claim 12, since that would appear to require both 30 and 40 to be variable pitch and applicant does not have possession of either of those being variable pitch, but rather were disclosed as fixed. Applicant’s argument that “Nothing in the Specification restricts variable-pitch stator blades to unducted engines” is not persuasive. Applicant’s teaching that the “the exhaust-nozzle/chevron pattern invention is applicable to both ducted and unducted architectures” is taken to be applicable to stator blades, but is not applicable to variable pitch stator blades unless specifically taught as such, especially when the specification teaches each of stator vane / blades 32, 40 are taught rather are fixed, rather than variable pitch.
Applicant further argues that
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In rebuttal, applicant ignores the Examiner’s treatment of Vassberg, where he teaches but does not illustrate the use of multiple chevrons per stator blade. Note Vassberg et al illustrate a single chevron per stator blade but teach the number of chevron peaks/valleys are integer multiples of the number of stator blades [see paragraph 0021]. In the Figs, the valley is aligned with the longitudinal line and when the stator is aligned with the longitudinal line in Fig. 8. Note that using numbers of integer multiples (e.g. 2, 3, 4, 5, etc.) would result in the there being multiple (e.g. 2, 3, 4, 5, respectively) peaks being the longitudinal lines, e.g. for 3 peaks, there are 3 chevron peaks between lines - for 5 peaks, 5 chevron peaks between lines - for 4 peaks, 4 peaks between lines, etc. In such a situation, these chevrons may arbitrarily be grouped with the first trailing edge patterns aligned with the stator blades and the second trailing patterns between the stator blades. These numbers are variable based on the number of chevrons, e.g. 5 chevrons as the integer multiple, results in 5 chevrons of which one, two, three, or four may be in the first pattern and four, three, two, one, respectively may be in the second pattern. Accordingly, applicant’s arguments fail to persuade.
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.
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/Ted Kim/
Telephone
571-272-4829
Primary Examiner
Fax
571-273-8300
February 24, 2026
1 for claims 3, 5, the teachings of either Mengle (2010/0257865) of the IDS or Tse (6640537) or not optional.