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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 7/13/2026 has been entered.
Claim Rejections - 35 USC § 103
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 (i.e., changing from AIA to pre-AIA ) 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.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claims 1, 4, 6, 8, 17, and 20-32 are rejected under 35 U.S.C. 103 as being unpatentable over McCaldon (12339005) in view of Mandai (7360363).
Regarding claim 1, McCaldon discloses a turbine engine having a compression section (24, fig 1), combustion section (26, fig 1), and turbine section (28, fig 1) is serial flow arrangement, the turbine engine comprising: a fuel injector (98, fig 7) comprising: an outer wall (wall which inlets 74 open through, fig 7) in annular arrangement extending from a forward end (where air 40 enters axially, fig 7) to an outlet (at chamber 46, fig 7), the outer wall surrounding an interior having a non-swirling air passage (52, fig 7), and the outer wall defining a central longitudinal axis (50, fig 7); a center body (100, fig 7) positioned within the interior, a fuel passage (104, fig 7) fluidly coupled to the interior; and a set of air passages (72, fig 7) in annular arrangement about and extending through the outer wall and fluidly coupled to the interior aft of the fuel passage, wherein the set of air passages are arranged tangentially (74, fig 5) relative to the outer wall to impart a swirl to a flow of air provided from the set of air passages to the interior, wherein the fuel passage is configured to introduce fuel radially (102, fig 7) into the non-swirling air passage upstream of the set of air passages.
McCaldon does not disclose a center body passage that extends through the center body, the center body passage being coaxially aligned with the central longitudinal axis and configured to introduce a first flow of air into the interior, wherein the center body includes an aft end that defines an acute angle relative to the central longitudinal axis, and wherein non-swirling airflow introduced into the interior, including the first flow of air, comprises from 20% to 60% of a total airflow volume introduced into the interior of the fuel injector, and wherein the second flow of air comprises from 40% to 80% of the total airflow volume introduced into the interior of the fuel injector.
Mandai teaches a gas turbine nozzle (808, fig 9a) with a center body (208, fig 9a) with a fuel passage (gap between 208 and 150, fig 9b) comprising a center body passage (150, fig 9b) that extends through the center body, the center body passage being coaxially aligned with the central longitudinal axis (combustion air arrow downstream of the nozzle, fig 9a) and configured to introduce a first flow of air (combustion air going into 150b, fig 9b) into the interior, wherein the center body includes an aft end that defines an acute angle relative to the central longitudinal axis (angle between outer wall 208A and centerline along combustion air arrow forms an angle far less than 45 degrees, fig 9a).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the center body of the nozzle disclosed by McCaldon by using the center body of Mandai with a fuel passage within the center body and a center body passage aligned with the axis configured to introduce air into the interior of the center body with an aft end defining an acute angle. Doing so would allow the air to be exhausted from the nozzle to increase flow velocity uniformity (col 11, lines 43-50), as suggested by Mandai.
The presence of a known result-effective variable would be a motivation for a person of ordinary skill in the art to experiment to reach another workable product or process. See KSR; MPEP 2144.05(II)(B). A particular parameter is a result-effective variable when the variable is known to achieve a recognized result. See In re Antonie, 559 F2d 618, 620, 195 USPQ 6,8 (CCPA 1977).
Here, McCaldon teaches that the air swirler is designed in conjunction with the air mixing chamber to tailor air flow rates and swirl distribution within the combustion chamber (col 4, lines 14-35). Therefore, an ordinary skill worker would recognize that the ratio of air from the swirler and non-swirl air flow sources is a result-effective variable that impacts the induced swirl and total air flow within the combustion chamber. Thus, the non-swirling airflow introduced into the interior, including the first flow of air, comprising from 20% to 60% of a total airflow volume introduced into the interior of the fuel injector, and wherein the second flow of air comprises from 40% to 80% of the total airflow volume introduced into the interior of the fuel injector is found to be an obvious optimization of the prior art obtainable by an ordinary skilled worker through routine experimentation.
Therefore, since the general conditions of the claim, i.e. relative air flow rates between the swirling and non-swirling air sources, were disclosed in the prior art by McCaldon, it is not inventive to discover the optimum workable range by routine experimentation, and it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the air flow ratio of McCaldon by having non-swirling airflow introduced into the interior, including the first flow of air, comprises from 20% to 60% of a total airflow volume introduced into the interior of the fuel injector, and having the second flow of air comprises from 40% to 80% of the total airflow volume introduced into the interior of the fuel injector, in order to tailor air flow and induced swirl to application specific needs (col 4, lines 32-36) as taught by McCaldon. It has been held “where the general conditions of a claim are discloses in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation”, In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955).
Regarding claim 4, McCaldon discloses wherein the center body is spaced from the outer wall, and wherein the non-swirling air passage is at least partially defined between the outer wall and the center body.
Regarding claim 6, McCaldon discloses wherein the center body further comprises a center body outer wall (outside of 100, fig 7), and wherein the fuel passage extends within the center body outer wall.
Regarding claim 8, McCaldon discloses wherein the fuel passage exhausts through the center body outer wall to the non-swirling air passage (102, fig 7).
Regarding claim 17, McCaldon discloses a fuel injector for a turbine engine (98, fig 7) the fuel injector comprising: an outer wall (wall which air holes 72 flow through, fig 7) in annular arrangement extending from a forward end (where air 40 enters axially, fig 7) to an outlet (at chamber 46, fig 7), the outer wall surrounding an interior having a non-swirling air passage (52, fig 7), and the outer wall defining a longitudinal axis (50, fig 7); a center body (100, fig 7) positioned within the interior, a fuel passage (104, fig 7) fluidly coupled to the interior; and a set of air passages (72, fig 7) in annular arrangement extending through the outer wall and fluidly coupled to the interior aft of the fuel passage, wherein the set of air passages are arranged tangentially (74, fig 5) relative to the outer wall to impart a swirl to a flow of air provided from the set of air passages to the interior, wherein the fuel passage is configured to introduce fuel radially (102, fig 7) into the non-swirling air passage upstream of the set of air passages.
McCaldon does not disclose a center body passage that extends through the center body, the center body passage being coaxially aligned with the central longitudinal axis and configured to introduce a first flow of air into the interior, wherein the center body includes an aft end that defines an acute angle relative to the central longitudinal axis, and wherein non-swirling airflow introduced into the interior, including the first flow of air, comprises from 20% to 60% of a total airflow volume introduced into the interior of the fuel injector, and wherein the second flow of air comprises from 40% to 80% of the total airflow volume introduced into the interior of the fuel injector.
Mandai teaches a gas turbine nozzle (808, fig 9a) with a center body (208, fig 9a) with a fuel passage (gap between 208 and 150, fig 9b) comprising a center body passage (150, fig 9b) that extends through the center body, the center body passage being coaxially aligned with the central longitudinal axis (combustion air arrow downstream of the nozzle, fig 9a) and configured to introduce a first flow of air (combustion air going into 150b, fig 9b) into the interior, wherein the center body includes an aft end that defines an acute angle relative to the central longitudinal axis (angle between outer wall 208A and centerline along combustion air arrow forms an angle far less than 45 degrees, fig 9a).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the center body of the nozzle disclosed by McCaldon by using the center body of Mandai with a fuel passage within the center body and a center body passage aligned with the axis configured to introduce air into the interior of the center body with an aft end defining an acute angle. Doing so would allow the air to be exhausted from the nozzle to increase flow velocity uniformity (col 11, lines 43-50), as suggested by Mandai.
The presence of a known result-effective variable would be a motivation for a person of ordinary skill in the art to experiment to reach another workable product or process. See KSR; MPEP 2144.05(II)(B). A particular parameter is a result-effective variable when the variable is known to achieve a recognized result. See In re Antonie, 559 F2d 618, 620, 195 USPQ 6,8 (CCPA 1977).
Here, McCaldon teaches that the air swirler is designed in conjunction with the air mixing chamber to tailor air flow rates and swirl distribution within the combustion chamber (col 4, lines 14-35). Therefore, an ordinary skill worker would recognize that the ratio of air from the swirler and non-swirl air flow sources is a result-effective variable that impacts the induced swirl and total air flow within the combustion chamber. Thus, the non-swirling airflow introduced into the interior, including the first flow of air, comprising from 20% to 60% of a total airflow volume introduced into the interior of the fuel injector, and wherein the second flow of air comprises from 40% to 80% of the total airflow volume introduced into the interior of the fuel injector is found to be an obvious optimization of the prior art obtainable by an ordinary skilled worker through routine experimentation.
Therefore, since the general conditions of the claim, i.e. relative air flow rates between the swirling and non-swirling air sources, were disclosed in the prior art by McCaldon, it is not inventive to discover the optimum workable range by routine experimentation, and it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the air flow ratio of McCaldon by having non-swirling airflow introduced into the interior, including the first flow of air, comprises from 20% to 60% of a total airflow volume introduced into the interior of the fuel injector, and having the second flow of air comprises from 40% to 80% of the total airflow volume introduced into the interior of the fuel injector, in order to tailor air flow and induced swirl to application specific needs (col 4, lines 32-36) as taught by McCaldon. It has been held “where the general conditions of a claim are discloses in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation”, In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955).
Regarding claim 20, McCaldon discloses wherein the center body is spaced from the outer wall, wherein the non-swirling air passage is at least partially defined between the outer wall and the center body.
Regarding claim 21, McCaldon discloses wherein the non-swirling air passage defines a first mixing region configured for mixing of non-swirling air and fuel (the area next to injection holes 102, fig 7).
Regarding claim 22, McCaldon discloses wherein the set of air passages are configured to impart a swirling airflow to a second mixing region (area next to swirling air holes 74, fig 7) upstream of the outlet and downstream of the first mixing region.
Regarding claim 23, McCaldon discloses wherein the swirling airflow from the set of air passages is configured to increase turbulence and enhance mixing of the fuel and air (swirlers are going to enhance turbulence and mixing via their nature, thus the swirlers meet this limitation).
Regarding claim 24, McCaldon discloses wherein the first mixing region and the second mixing region are configured to improve flame stability during combustion (this represents intended use of the mixing regions, since structurally the regions of McCaldon are the same ones claimed they would operate the same).
Regarding claim 25, McCaldon discloses wherein the non-swirling air passage defines a first mixing region configured for mixing of non-swirling air and fuel (the area next to injection holes 102, fig 7).
Regarding claim 26, McCaldon discloses wherein the set of air passages are configured to impart a swirling airflow to a second mixing region (area next to swirling air holes 74, fig 7) upstream of the outlet and downstream of the first mixing region.
Regarding claim 27, McCaldon discloses wherein the swirling airflow from the set of air passages is configured to increase turbulence and enhance mixing of the fuel and air (swirlers are going to enhance turbulence and mixing via their nature, thus the swirlers meet this limitation).
Regarding claim 28, McCaldon discloses wherein the first mixing region and the second mixing region are configured to improve flame stability during combustion (this represents intended use of the mixing regions, since structurally the regions of McCaldon are the same ones claimed they would operate the same).
Regarding claim 29, McCaldon discloses wherein the second flow of air defines a swirled flow of air (as per claim 1, the air passages are tangential to impart swirl to the second flow of air), and wherein fuel from the fuel passage mixes with the non-swirling air to form a fuel-air mixture (the fuel passages are upstream of the swirling flow of air in the non-swirl section), and wherein the fuel-air mixture flows downstream to the interior so that when the swirled flow of air from the set of air passages is introduced into the interior, the fuel-air mixture in the interior interacts with the swirled flow of air in the interior (the mixed flow flows downstream of the nozzle into the interior of the nozzle towards the swirler as it mixes with the non-swirl air).
Regarding claim 30, McCaldon as modified by Mandai discloses wherein the fuel passage is radially farther from the longitudinal axis than the center body passage (Mandai, fig 9b, the fuel passages are located on the outer wall of the center body between 150 and 208).
Regarding claim 31, McCaldon as modified by Mandai discloses wherein the center body further comprises a center body outlet (150a, fig 9b, Mandai), and wherein the center body outlet is axially offset from a fuel passage outlet (McCaldon, the fuel outlets are on the outer radial surface of the center body, which is axially offset from the centerline where the center body outlet is located) and upstream of the outlet of the outer wall (150a is at the very downstream tip, and thus the fuel passage outlets would be upstream of them).
Regarding claim 32, McCaldon as modified by Mandai in claim 1 does not disclose wherein the acute angle defined by the aft end of the center body is from 45 degrees to less than 90 degrees relative to the central longitudinal axis.
Mandai further teaches wherein the acutely angled aft end of the nozzle center body can be between 45 and 90 degrees relative to the central longitudinal axis (206a, fig 7, the aft end is steeper than 45 degrees).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have the acute angle of the nozzle center body be between 45 and 90 degrees based on the teachings of Mandai. A change in form or shape is generally recognized as being within the level of ordinary skill in the art, absent any showing of unexpected results. In re Dailey et al., 149 USPQ 47.
Claims 9 and 10 are rejected under 35 U.S.C. 103 as being unpatentable over McCaldon as modified by Mandai in claim 1, further in view of Naiks (11692709).
Regarding claims 9 and 10, McCaldon does not disclose wherein the outer wall comprises a converging portion, and wherein the converging portion is positioned aft of the set of air passages.
Naiks teaches a fuel nozzle wherein the outer wall comprises a converging portion (218, fig 1), and wherein the converging portion is positioned aft of the set of air passages (fig 4a, it’s downstream of the air passages).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the aft end of the fuel nozzle disclosed by McCaldon as modified by Mandai by having a converging portion downstream of the air passages based on the teachings of Naiks. Doing so would allow for the mixing air to maintain a high velocity (col 7, lines 37-46) which is known in the art to reduce any chance of backfire within the nozzle, as suggested by Naiks.
Response to Arguments
Applicant's arguments filed 3/13/2026 have been fully considered but they are not persuasive. Applicant argues that the prior art does not show the non-swirling airflow comprising between 20 and 60% of airflow while swirling airflow comprising 40-80% of air. This argument is not persuasive as although the prior art does not explicitly provide these numbers, the amount of air flow is directly proportional to the inlet area, and since the inlet area of the swirling air 74 appears to be relatively similar to the inlet of the non-swirling air inlet, and in applicants own specification these volumes are described as “non-limiting examples” and thus aren’t critical to the operation of the invention. These ranges represent a routine optimization of the size of the inlets and thus are anticipated by McCaldon.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to SEAN V MEILLER whose telephone number is (571)272-9229. The examiner can normally be reached 7am-5pm.
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/SEAN V MEILLER/Examiner, Art Unit 3741
/DEVON C KRAMER/Supervisory Patent Examiner, Art Unit 3741
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