DETAILED ACTION
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 02/02/2026 entering the After Final Amendments filed on 01/06/2026 amending Claims 1 and 12 and canceling Claims 4 and 14 has been entered.
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 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, 5, 6, 8, 12, 16, and 18 are rejected under 35 U.S.C. 103 as being unpatentable over Mizukami et al. (10,352,243) in view of Fath (7,085,644) in view of Ullyott et al. (10,710,738).
Regarding Claim 1, Mizukami teaches, in Figs. 2 and 4 - 9, the invention as claimed including a gas turbine engine (10) comprising: a turbine section (13) located at an engine central longitudinal axis (along 25); a combustor (12) configured to drive rotation of the turbine with combustion products (29); a compressor section (11) coupled to the turbine section at the engine central longitudinal axis and driven by the turbine section (via shaft 25); and an auxiliary compressor (40) disposed fluidly between the compressor section and the combustor such that an airflow exiting the compressor section (28) is directed toward the auxiliary compressor (40), the auxiliary compressor driven independently from the compressor section (via 41) and configured to output the airflow (46) toward the combustor (12); an intercooler heat exchanger (31, 32) disposed fluidly between the compressor section and the auxiliary compressor to cool the airflow exiting the compressor section (28, Col. 9, ll. 4 - 20); and an intercooler valve (36); wherein the airflow is cooled at the intercooler heat exchanger (31, 32) via an airflow (Col. 9, ll. 10 – 20).
Mizukami is silent on said intercooler valve operable to selectably allow the airflow to selectably bypass the intercooler heat exchanger while still directing the airflow through the auxiliary compressor.
Fath teaches, in Fig. 1b and Col. 6, ll. 55 – 60, a similar intercooler heat exchanger (6’) having a bypass pipe (14) with an intercooler valve (15) operable to selectably allow the airflow to selectably bypass (Col. 6, ll. 55 – 60) the intercooler heat exchanger (6’) while still directing the airflow to the components (e.g., 7’, 12, 1’) downstream of the intercooler heat exchanger (6’).
It would have been obvious, to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify Mizukami with the intercooler and said intercooler valve arrangement wherein said intercooler valve is operable to selectably allow the airflow to selectably bypass the intercooler heat exchanger while still directing the airflow to downstream components, taught by Fath, because all the claimed elements, i.e., the gas turbine engine having a compressor section, combustor, and turbine section in serial fluid flow arrangement, an intercooler heat exchanger disposed fluidly between the compressor section and the auxiliary compressor, and an intercooler valve operable to selectably allow the airflow to selectably bypass the intercooler heat exchanger while still directing the airflow through the auxiliary compressor, were known in the art, and one skilled in the art could have substituted the intercooler, bypass pipe, and intercooler valve arrangement, taught by Fath, for the intercooler arrangement of Mizukami, with no change in their respective functions, to yield predictable results, i.e., the intercooler valve in the bypass pipe flow path would have been operable to selectably allow the airflow to selectably bypass the intercooler heat exchanger (through the bypass pipe flow path when said intercooler valve was open) while still directing the airflow to and through the auxiliary compressor (40 - Mizukami - Figs. 2 and 4 - 9). KSR, 550 U.S. 398 (2007), 82 USPQ2d at 1395; MPEP 2143(B).
Mizukami, i.v., Fath, as discussed above, is silent on said airflow cooling said intercooler heat exchanger being a RAM airflow.
Ullyott teaches, in Figs. 3 – 8 and Col. 11, ll. 45 - 50, a similar intercooler heat exchanger (26, 126, and/or 226) being cooled by fan (92) airflow or RAM airflow.
It would have been obvious, to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify Mizukami, i.v., Fath, with the airflow being RAM airflow, taught by Ullyott, because all the claimed elements, i.e., the gas turbine engine having a compressor section, combustor, and turbine section in serial fluid flow arrangement, an intercooler heat exchanger disposed fluidly between the compressor section and the auxiliary compressor, and using RAM airflow as the heat sink (coolant) of an intercooler, were known in the art, and one skilled in the art could have substituted the RAM airflow, taught by Ullyott, for the fan airflow of Mizukami, i.v., Fath, with no change in their respective functions, to yield predictable results, i.e., the RAM airflow would have functioned as the heat sink (coolant) of said intercooler heat exchanger resulting in cooling the compressor section airflow. KSR, 550 U.S. 398 (2007), 82 USPQ2d at 1395; MPEP 2143(B).
Re Claim 5, Mizukami, i.v., Fath and Ullyott, teaches the invention as claimed and as discussed above, and Mizukami further teaches, including a compressor valve (36) operable to allow the airflow to selectably bypass the auxiliary compressor (bypassing 31, 40 and flowing 28 straight to combustor 12).
Re Claim 6, Mizukami, i.v., Fath and Ullyott, teaches the invention as claimed and as discussed above, and Mizukami further teaches, including an electric motor (41 – Col. 9, ll. 24 - 26) to drive the auxiliary compressor (40).
Re Claim 8, Mizukami, i.v., Fath and Ullyott, teaches the invention as claimed and as discussed above, and Mizukami further teaches, including wherein the auxiliary compressor (40) is located remotely from the engine central longitudinal axis (25), best seen in Figs. 2 and 4 - 9.
Regarding Claim 12, Mizukami teaches, in Figs. 2 and 4 - 9, the invention as claimed including a method of operating a gas turbine engine (10), comprising: driving rotation of a compressor section (11) of the gas turbine engine by rotation of a turbine section (13) of the gas turbine engine; compressing an airflow (Atmospheric Air) at the compressor section (11); further compressing the airflow at an auxiliary compressor (40) driven independently from the compressor section (by 41); combusting the further compressed airflow at a combustor section (12) to drive rotation of the turbine section with the combustion products (29); cooling the airflow at an intercooler heat exchanger (31, 32 - Col. 9, ll. 10 - 20) before further compressing the airflow at the auxiliary compressor (40); directing the airflow to selectably bypass the intercooler heat exchanger (31, 32) via operation of one or more valves (36); wherein the airflow is cooled at the intercooler heat exchanger (31, 32) via an airflow (Col. 9, ll. 4 – 20 “Thus, the cooler 31 cools the compressed air flowing through the radiator 32 by way of rotating the fan 33 and blowing air against the radiator 32…”.)
Mizukami is silent on said directing the airflow to selectably bypass the intercooler heat exchanger being while still directing the airflow through the auxiliary compressor via operation of one or more valves.
Fath teaches, in Fig. 1b and Col. 6, ll. 55 – 60, a similar intercooler heat exchanger (6’) having a bypass pipe (14) with an intercooler valve (15) operable to selectably allow the airflow to selectably bypass (Col. 6, ll. 55 – 60) the intercooler heat exchanger (6’) while still directing the airflow to the components (e.g., 7’, 12, 1’) downstream of the intercooler heat exchanger (6’).
It would have been obvious, to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify Mizukami with the intercooler and said intercooler valve arrangement wherein said intercooler valve is operable to direct the airflow to selectably bypass the intercooler heat exchanger while still directing the airflow to downstream components via operation of one or more valves, taught by Fath, because all the claimed elements, i.e., the gas turbine engine having a compressor section, combustor, and turbine section in serial fluid flow arrangement, an intercooler heat exchanger disposed fluidly between the compressor section and the auxiliary compressor, and an intercooler valve operable to selectably allow the airflow to selectably bypass the intercooler heat exchanger while still directing the airflow through the auxiliary compressor, were known in the art, and one skilled in the art could have substituted the intercooler, bypass pipe, and intercooler valve arrangement, taught by Fath, for the intercooler arrangement of Mizukami, with no change in their respective functions, to yield predictable results, i.e., the intercooler valve in the bypass pipe flow path would have been operable to selectably allow the airflow to selectably bypass the intercooler heat exchanger (through the bypass pipe flow path when said intercooler valve was open) while still directing the airflow to and through the auxiliary compressor (40 - Mizukami - Figs. 2 and 4 - 9). KSR, 550 U.S. 398 (2007), 82 USPQ2d at 1395; MPEP 2143(B).
Mizukami, i.v., Fath, as discussed above, is silent on said airflow cooling said intercooler heat exchanger being a RAM airflow.
Ullyott teaches, in Figs. 3 – 8 and Col. 11, ll. 45 - 50, a similar intercooler heat exchanger (26, 126, and/or 226) being cooled by fan (92) airflow or RAM airflow.
It would have been obvious, to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify Mizukami, i.v., Fath, with the airflow being RAM airflow, taught by Ullyott, because all the claimed elements, i.e., the gas turbine engine having a compressor section, combustor, and turbine section in serial fluid flow arrangement, an intercooler heat exchanger disposed fluidly between the compressor section and the auxiliary compressor, and using RAM airflow as the heat sink (coolant) of an intercooler, were known in the art, and one skilled in the art could have substituted the RAM airflow, taught by Ullyott, for the fan airflow of Mizukami, i.v., Fath, with no change in their respective functions, to yield predictable results, i.e., the RAM airflow would have functioned as the heat sink (coolant) of said intercooler heat exchanger resulting in cooling the compressor section airflow. KSR, 550 U.S. 398 (2007), 82 USPQ2d at 1395; MPEP 2143(B).
Re Claim 16, Mizukami, i.v., Fath and Ullyott, teaches the invention as claimed and as discussed above, and Mizukami further teaches, including wherein the auxiliary compressor (40) is driven by an electric motor (41 – Col. 9, ll. 24 - 26).
Re Claim 18, Mizukami, i.v., Fath and Ullyott, teaches the invention as claimed and as discussed above, and Mizukami further teaches, including wherein the auxiliary compressor (40) is located remotely from the engine central longitudinal axis (25), best seen in Figs. 2 and 4 - 9.
Claims 7 and 17 are rejected under 35 U.S.C. 103 as being unpatentable over Mizukami et al. (10,352,243) in view of Fath (7,085,644) in view of Ullyott et al. (10,710,738) in further view of Roberge (2019/0353103A1).
Re Claims 7 and 17, Fath and Ullyott, teaches the invention as claimed and as discussed above, including, in Figs. 2 and 4 - 9, a generator (14 – Col. 7, ll. 65 - 67) operably connected to the turbine section (13).
Mizukami, i.v., Fath and Ullyott, as discussed above, is silent on wherein electrical energy to drive the electric motor is from said generator.
Roberge teaches, in Figs. 1 and 2, a similar gas turbine engine (20) with a turbine section (54, 46) driving a generator (92, 94), and an auxiliary compressor (72) driven by an electric motor (82), wherein the electrical energy to drive the electric motor (82) is from said generator(s), Para. [0048].
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Mizukami, i.v., Fath and Ullyott, with the electrical energy to drive the electric motor is from said generator operably connected to the turbine section, taught by Roberge, in order to make use of the available electrical power from the gas turbine engine to drive the required electric motor operation rather than using an external or single-use source, Roberge – Para. [0048].
Claims 9 and 19 are rejected under 35 U.S.C. 103 as being unpatentable over Mizukami et al. (10,352,243) in view of Fath (7,085,644) in view of Ullyott et al. (10,710,738) in further view of Brostmeyer et al. (2016/0215694A1).
Re Claims 9 and 19, Mizukami, i.v., Fath and Ullyott, teaches the invention as claimed and as discussed above; except, wherein the turbine section includes a variable pitch vane stage.
Brostmeyer teaches, in Figs. 5 – 7 and 9, a similar gas turbine engine having a turbine section (61 – Figs. 5 – 7, 91 – Fig. 9) includes a variable pitch vane stage (63 – Figs. 5 – 7, 93 – Fig. 9).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify Mizukami, i.v., Fath and Ullyott, with the variable pitch vane stage in the turbine section, taught by Brostmeyer, to facilitate controlling the flow of combustion gases through the turbine section to facilitate a better match between the rotational speeds of the low pressure compressor and the high pressure compressor (Para. [0053]).
Claims 10, 11, and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Mizukami et al. (10,352,243) in view of Fath (7,085,644) in view of Ullyott et al. (10,710,738) in further view of Hanrahan et al. (2020/0040848A1).
Re Claims 10 and 11, Mizukami, i.v., Fath and Ullyott, teaches the invention as claimed and as discussed above, Mizukami further teaches, in Figs. 2 and 4 - 9, including a high pressure spool including: a high pressure turbine (13) of the turbine section; and a high pressure compressor (11) of the compressor section coupled to (via shaft 25) the high pressure turbine (13) and driven by the high pressure turbine (13); wherein the auxiliary compressor (40) is fluidly connected to an exit of the high pressure compressor (11) between the high pressure compressor (11) and the combustor (12).
Mizukami, i.v., Fath and Ullyott, as discussed above, is silent on (Claim 10) further comprising: a low pressure spool including: a low pressure turbine of the turbine section; and a low pressure compressor of the compressor section coupled to the low pressure turbine and driven by the low pressure turbine; and (Claim 11) wherein the low pressure spool and the high pressure spool are coaxial.
Hanrahan teaches, in Figs. 1 and 2, a similar gas turbine engine (Claim 10) having a low pressure spool (14 – Para. [0015]) including: a low pressure turbine (20) of a turbine section; and a low pressure compressor (18) of a compressor section coupled to (via shaft 22) the low pressure turbine (20) and driven by the low pressure turbine (20); and a high pressure spool (16 – Para. [0015]) including: a high pressure turbine (26) of a turbine section; and a high pressure compressor (24) of a compressor section coupled to (via shaft 28) the high pressure turbine (26) and driven by the high pressure turbine (26); wherein an auxiliary compressor (74, 91) is fluidly connected to an exit of the high pressure compressor (24) between the high pressure compressor (24) and a combustor (70), and (Claim 11) wherein the low pressure spool (14) and the high pressure spool (16) are coaxial (Para. [0015] “Low pressure spool 14 and high pressure spool 16 are coaxial, each extending along and rotating about centerline axis 37 independently of one another”).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify Mizukami, i.v., Fath and Ullyott, with the low pressure spool including: a low pressure turbine of the turbine section; and a low pressure compressor of the compressor section coupled to the low pressure turbine and driven by the low pressure turbine; and the low pressure spool being coaxial with the high pressure spool, taught by Hanrahan, because all the claimed elements, i.e., the two-spool gas turbine engine having a low pressure spool coaxial with a high pressure spool where the low pressure spool included a low pressure compressor coupled to and driven by a low pressure turbine, where the high pressure spool included a high pressure compressor coupled to and driven by a high pressure turbine, and an auxiliary compressor fluidly connected to an exit of the high pressure compressor between the high pressure compressor and a combustor, were known in the art, in combination each one of the components would perform the same function as it did separately, and one skilled in the art could have combined the elements as claimed by known methods, with no change in their respective functions, to yield predictable results, i.e., integrating a low pressure spool coaxial with the high pressure spool of Mizukami, i.v., Fath and Ullyott, would have facilitated more efficient operation across a wider range of speeds and altitudes compared to the single-spool design because the low pressure compressor coupled to and driven by the low pressure turbine would have been free to rotate at the optimum rotational speeds for the low pressure compressor while the high pressure compressor coupled to and driven by the high pressure turbine would have been free to rotate at the optimum rotational speeds for the high pressure compressor. KSR, 550 U.S. 398 (2007), 82 USPQ2d at 1395; MPEP 2143(A).
Re Claim 20, Mizukami, i.v., Fath and Ullyott, teaches the invention as claimed and as discussed above; except, wherein the gas turbine engine is a two-spool gas turbine engine and the auxiliary compressor is located fluidly between a high pressure compressor section and the combustor.
Hanrahan teaches, in Figs. 1 and 2, a similar two-spool gas turbine engine having a low pressure spool (14 – Para. [0015]) including: a low pressure turbine (20) of a turbine section; and a low pressure compressor (18) of a compressor section coupled to (via shaft 22) the low pressure turbine (20) and driven by the low pressure turbine (20); and a high pressure spool (16 – Para. [0015]) including: a high pressure turbine (26) of a turbine section; and a high pressure compressor (24) of a compressor section coupled to (via shaft 28) the high pressure turbine (26) and driven by the high pressure turbine (26); wherein an auxiliary compressor (74, 91) is located fluidly between a high pressure compressor (24) section and the combustor (70).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify Mizukami, i.v., Fath and Ullyott, with the low pressure spool including: a low pressure turbine of the turbine section; and a low pressure compressor of the compressor section coupled to the low pressure turbine and driven by the low pressure turbine; and the low pressure spool being coaxial with the high pressure spool, taught by Hanrahan, because all the claimed elements, i.e., the two-spool gas turbine engine having a low pressure spool coaxial with a high pressure spool where the low pressure spool included a low pressure compressor coupled to and driven by a low pressure turbine, where the high pressure spool included a high pressure compressor coupled to and driven by a high pressure turbine, and an auxiliary compressor fluidly connected to an exit of the high pressure compressor between the high pressure compressor and a combustor, were known in the art, in combination each one of the components would perform the same function as it did separately, and one skilled in the art could have combined the elements as claimed by known methods, with no change in their respective functions, to yield predictable results, i.e., integrating a low pressure spool coaxial with the high pressure spool of Mizukami, i.v., Fath and Ullyott, would have facilitated more efficient operation across a wider range of speeds and altitudes compared to the single-spool design because the low pressure compressor coupled to and driven by the low pressure turbine would have been free to rotate at the optimum rotational speeds for the low pressure compressor while the high pressure compressor coupled to and driven by the high pressure turbine would have been free to rotate at the optimum rotational speeds for the high pressure compressor. KSR, 550 U.S. 398 (2007), 82 USPQ2d at 1395; MPEP 2143(A).
Claims 1, 6 – 8, 10 – 12, 16 – 18, and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Hanrahan et al. (2020/0040848A1) in view of Macchia et al. (11,352,954) in view of Fath (7,085,644).
Regarding Claim 1, Hanrahan teaches, in Figs. 1 – 6, the invention as claimed including a gas turbine engine (10 – Fig. 1) comprising: a turbine section (20, 26) located at an engine central longitudinal axis (37); a combustor (70) configured to drive rotation of the turbine section (20, 26) with combustion products (58 – Para. [0018]); a compressor section (18, 24) coupled to the turbine section (via shafts 22 and 28) at the engine central longitudinal axis (37) and driven by the turbine section (20, 26 – Para. [0015]); and an auxiliary compressor (74, 91) disposed fluidly between the compressor section (18, 24) and the combustor (70) such that an airflow (105) exiting the compressor section (18, 24) is directed toward the auxiliary compressor (74, 91), the auxiliary compressor (74, 91) driven independently (86 – Fig. 2 – Para. [0026]) from the compressor section and configured to output the airflow (106) toward the combustor (70 – Para. [0027]).
Hanrahan is silent on an intercooler heat exchanger disposed fluidly between the compressor section and the auxiliary compressor to cool the airflow exiting the compressor section; wherein the airflow is cooled at the intercooler heat exchanger via a RAM airflow.
Macchia teaches, in Figs. 1 – 12, a similar gas turbine engine (102 – Fig. 2) comprising: a turbine section (214) located at an engine central longitudinal axis (244); a combustor (208) configured to drive rotation of the turbine section (214) with combustion products (252 – Col. 3, ll. 5 - 25); a compressor section (300) coupled to the turbine section (via shafts) at the engine central longitudinal axis (244) and driven by the turbine section (214 – Col. 3, ll. 5 - 25), an intercooler heat exchanger (500 – Fig. 5, 900 – Figs. 8 and 9, 1000 – Fig. 10, 1100 – Fig. 11) disposed fluidly between the compressor section (300) and downstream component to cool the airflow (250) exiting the compressor section (300 – Col. 7, ll. 65 – 67 “Although shown schematically with a particular structure in FIG. 5, the heat exchanger 500 may generally be any heat exchanger facilitating heat transfer between the compressed air 250 and ram air 210.”); wherein the airflow (250) is cooled at the intercooler heat exchanger via a RAM airflow (116, 210 – Col. 10, ll. 65 – 67 “In some embodiments of the method 1300, the second air flow 116 is received into the GTE 102 as ram air 210.”).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify Hanrahan, with the intercooler heat exchanger disposed fluidly between the compressor section and a downstream component to cool the airflow exiting the compressor section; wherein the airflow is cooled at the intercooler heat exchanger via a RAM airflow, taught by Maccia, because all the claimed elements, i.e., the gas turbine engine having a compressor section, combustor, and turbine section in serial fluid flow arrangement, an auxiliary compressor disposed fluidly between the compressor section and the combustor such that an airflow exiting the compressor section is directed toward the auxiliary compressor, the auxiliary compressor driven independently from the compressor section and configured to output the airflow toward the combustor; and an intercooler heat exchanger disposed fluidly between the compressor section and a downstream component to cool the airflow exiting the compressor section; wherein the airflow is cooled at the intercooler heat exchanger via a RAM airflow, were known in the art, in combination each one of the components would perform the same function as it did separately, and one skilled in the art could have combined the elements as claimed by known methods, with no change in their respective functions, to yield predictable results, i.e., integrating the intercooler heat exchanger in the compressed airflow path between the compressor section and the auxiliary compressor would have facilitated using RAM airflow as the heat sink fluid, i.e., coolant, to cool the airflow exiting the compressor section thereby improving efficiency of the gas turbine engine. Maccia teaches, in Col. 7, ll. 35 – 40, “By receiving ram air 210 directly into the GTE 102 to facilitate intercooling, the intercooling stage 410 may thereby not be excessively parasitic to the core gas path 242 or the bypass flow 240 to achieve an intercooling effect to increase engine efficiency.” KSR, 550 U.S. 398 (2007), 82 USPQ2d at 1395; MPEP 2143(A).
Hanrahan, i.v., Maccia, is silent on an intercooler valve operable to selectably allow the airflow to selectably bypass the intercooler heat exchanger while still directing the airflow through the auxiliary compressor.
Fath teaches, in Fig. 1b and Col. 6, ll. 55 – 60, a similar intercooler heat exchanger (6’) having a bypass pipe (14) with an intercooler valve (15) operable to selectably allow the airflow to selectably bypass (Col. 6, ll. 55 – 60) the intercooler heat exchanger (6’) while still directing the airflow to the components (e.g., 7’, 12, 1’) downstream of the intercooler heat exchanger (6’).
It would have been obvious, to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify Hanrahan, i.v., Maccia, with the intercooler valve is operable to selectably allow the airflow to selectably bypass the intercooler heat exchanger while still directing the airflow to downstream components, taught by Fath, because all the claimed elements, i.e., the gas turbine engine having a compressor section, combustor, and turbine section in serial fluid flow arrangement, an intercooler heat exchanger disposed fluidly between the compressor section and the auxiliary compressor, and an intercooler valve operable to selectably allow the airflow to selectably bypass the intercooler heat exchanger while still directing the airflow through the auxiliary compressor, were known in the art, in combination each one of the components would perform the same function as it did separately, and one skilled in the art could have combined the elements as claimed by known methods, with no change in their respective functions, to yield predictable results, i.e., integrating the intercooler valve and bypass flowpath into the intercooler heat exchanger arrangement of Hanrahan, i.v., Maccia, would have facilitated having the option to bypass the compressed airflow from the compressor section around the intercooler heat exchanger and then to the auxiliary compressor when cooling the airflow exiting the compressor section was not desired or required because the temperature of the compressed airflow was below a threshold temperature. KSR, 550 U.S. 398 (2007), 82 USPQ2d at 1395; MPEP 2143(B).
Re Claim 6, Hanrahan, i.v., Maccia and Fath, teaches the invention as claimed and as discussed above, and Hanrahan further teaches, including an electric motor (86 – Para. [0026] “In other embodiments, each of electric machines 86, 88, and 90 can be motor-generators, capable of producing electric power or being driven by electric power received from one of the other motor-generators operating in generator mode.”) to drive the auxiliary compressor (74, 91).
Re Claim 7, Hanrahan, i.v., Maccia and Fath, teaches the invention as claimed and as discussed above, and Hanrahan further teaches, in Para. [0026], wherein electrical energy (from 88 and/or 90 operating in generator mode) to drive the electric motor (86 operating in motor mode) is from a generator (88 and/or 90 operating in generator mode) operably connected to the turbine section (214).
Re Claim 8, Hanrahan, i.v., Maccia and Fath, teaches the invention as claimed and as discussed above, and Hanrahan further teaches, in Figs. 1 and 2, including wherein the auxiliary compressor (74, 91) is located remotely from the engine central longitudinal axis (37).
Re Claims 10 and 11, Hanrahan, i.v., Maccia and Fath, teaches the invention as claimed and as discussed above, and Hanrahan further teaches, in Figs. 1 and 2, said gas turbine engine further comprising (Claim 10) a low pressure spool (14 – Para. [0015]) including: a low pressure turbine (20) of a turbine section; and a low pressure compressor (18) of a compressor section coupled to (via shaft 22) the low pressure turbine (20) and driven by the low pressure turbine (20); and a high pressure spool (16 – Para. [0015]) including: a high pressure turbine (26) of a turbine section; and a high pressure compressor (24) of a compressor section coupled to (via shaft 28) the high pressure turbine (26) and driven by the high pressure turbine (26); wherein an auxiliary compressor (74, 91) is fluidly connected to an exit of the high pressure compressor (24) between the high pressure compressor (24) and a combustor (70), and (Claim 11) wherein the low pressure spool (14) and the high pressure spool (16) are coaxial (Para. [0015] “Low pressure spool 14 and high pressure spool 16 are coaxial, each extending along and rotating about centerline axis 37 independently of one another”).
Regarding Claim 12, Hanrahan teaches, in Figs. 1 – 6, the invention as claimed including a method of operating a gas turbine engine (10 – Fig. 1), comprising: driving rotation (Para. [0018]) of a compressor section (18, 24) of the gas turbine engine by rotation of a turbine section (20, 26) of the gas turbine engine; compressing an airflow at the compressor section (18, 24 - Para. [0018]); further compressing the airflow at an auxiliary compressor (74, 91) driven independently (86 – Fig. 2 – Para. [0026]) from the compressor section (18, 24); combusting the further compressed airflow at a combustor section (70) to drive rotation of the turbine section (20, 26) with the combustion products (58 – Para. [0018]).
Hanrahan is silent on cooling the airflow at an intercooler heat exchanger before further compressing the airflow at the auxiliary compressor, wherein the airflow is cooled at the intercooler heat exchanger via a RAM airflow.
Macchia teaches, in Figs. 1 – 12, a similar gas turbine engine (102 – Fig. 2) comprising: a turbine section (214) located at an engine central longitudinal axis (244); a combustor (208) configured to drive rotation of the turbine section (214) with combustion products (252 – Col. 3, ll. 5 - 25); a compressor section (300) coupled to the turbine section (via shafts) at the engine central longitudinal axis (244) and driven by the turbine section (214 – Col. 3, ll. 5 - 25), an intercooler heat exchanger (500 – Fig. 5, 900 – Figs. 8 and 9, 1000 – Fig. 10, 1100 – Fig. 11) disposed fluidly between the compressor section (300) and downstream component to cool the airflow (250) exiting the compressor section (300 – Col. 7, ll. 65 – 67 “Although shown schematically with a particular structure in FIG. 5, the heat exchanger 500 may generally be any heat exchanger facilitating heat transfer between the compressed air 250 and ram air 210.”); wherein the airflow (250) is cooled at the intercooler heat exchanger via a RAM airflow (116, 210 – Col. 10, ll. 65 – 67 “In some embodiments of the method 1300, the second air flow 116 is received into the GTE 102 as ram air 210.”).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify Hanrahan, with the intercooler heat exchanger disposed fluidly between the compressor section and a downstream component to cool the airflow exiting the compressor section; wherein the airflow is cooled at the intercooler heat exchanger via a RAM airflow, taught by Maccia, because all the claimed elements, i.e., the gas turbine engine having a compressor section, combustor, and turbine section in serial fluid flow arrangement, an auxiliary compressor disposed fluidly between the compressor section and the combustor such that an airflow exiting the compressor section is directed toward the auxiliary compressor, the auxiliary compressor driven independently from the compressor section and configured to output the airflow toward the combustor; and an intercooler heat exchanger disposed fluidly between the compressor section and a downstream component to cool the airflow exiting the compressor section; wherein the airflow is cooled at the intercooler heat exchanger via a RAM airflow, were known in the art, in combination each one of the components would perform the same function as it did separately, and one skilled in the art could have combined the elements as claimed by known methods, with no change in their respective functions, to yield predictable results, i.e., integrating the intercooler heat exchanger in the compressed airflow path between the compressor section and the auxiliary compressor would have facilitated using RAM airflow as the heat sink fluid, i.e., coolant, to cool the airflow exiting the compressor section thereby improving efficiency of the gas turbine engine. Maccia teaches, in Col. 7, ll. 35 – 40, “By receiving ram air 210 directly into the GTE 102 to facilitate intercooling, the intercooling stage 410 may thereby not be excessively parasitic to the core gas path 242 or the bypass flow 240 to achieve an intercooling effect to increase engine efficiency.” KSR, 550 U.S. 398 (2007), 82 USPQ2d at 1395; MPEP 2143(A). It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, that in the combination of Hanrahan, i.v., Maccia, the airflow would have been cooled using RAM air at the intercooler heat exchanger before further compressing the now cooled airflow at the auxiliary compressor.
Hanrahan, i.v., Maccia, is silent on directing the airflow to selectably bypass the intercooler heat exchanger while still directing the airflow through the auxiliary compressor via operation of one or more valves.
Fath teaches, in Fig. 1b and Col. 6, ll. 55 – 60, a similar intercooler heat exchanger (6’) having a bypass pipe (14) with an intercooler valve (15) operable to selectably allow the airflow to selectably bypass (Col. 6, ll. 55 – 60) the intercooler heat exchanger (6’) while still directing the airflow to the components (e.g., 7’, 12, 1’) downstream of the intercooler heat exchanger (6’).
It would have been obvious, to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify Hanrahan, i.v., Maccia, with the intercooler valve is operable to selectably allow the airflow to selectably bypass the intercooler heat exchanger while still directing the airflow to downstream components, taught by Fath, because all the claimed elements, i.e., the gas turbine engine having a compressor section, combustor, and turbine section in serial fluid flow arrangement, an intercooler heat exchanger disposed fluidly between the compressor section and the auxiliary compressor, and an intercooler valve operable to selectably allow the airflow to selectably bypass the intercooler heat exchanger while still directing the airflow through the auxiliary compressor, were known in the art, in combination each one of the components would perform the same function as it did separately, and one skilled in the art could have combined the elements as claimed by known methods, with no change in their respective functions, to yield predictable results, i.e., integrating the intercooler valve and bypass flowpath into the intercooler heat exchanger arrangement of Hanrahan, i.v., Maccia, would have facilitated having the option of directing the airflow to selectably bypass the intercooler heat exchanger while still directing the airflow through the auxiliary compressor via operation of one or more intercooler valves installed in a bypass flowpath when cooling the airflow exiting the compressor section was not desired or required because the temperature of the compressed airflow was below a threshold temperature. KSR, 550 U.S. 398 (2007), 82 USPQ2d at 1395; MPEP 2143(B).
Re Claim 16, Hanrahan, i.v., Maccia and Fath, teaches the invention as claimed and as discussed above, and Hanrahan further teaches, in Para. [0026], wherein the auxiliary compressor (74, 91) is driven by an electric motor (86 – Para. [0026] “In other embodiments, each of electric machines 86, 88, and 90 can be motor-generators, capable of producing electric power or being driven by electric power received from one of the other motor-generators operating in generator mode.”).
Re Claim 17, Hanrahan, i.v., Maccia and Fath, teaches the invention as claimed and as discussed above, and Hanrahan further teaches, in Para. [0026], wherein electrical energy (from 88 and/or 90 operating in generator mode) to drive the electric motor (86 operating in motor mode) is from a generator (88 and/or 90 operating in generator mode) operably connected to the turbine section (214).
Re Claim 18, Hanrahan, i.v., Maccia and Fath, teaches the invention as claimed and as discussed above, and Hanrahan further teaches, in Figs. 1 and 2, including wherein the auxiliary compressor (74, 91) is located remotely from the engine central longitudinal axis (37).
Re Claim 20, Hanrahan, i.v., Maccia and Fath, teaches the invention as claimed and as discussed above, and Hanrahan further teaches, in Figs. 1 and 2, wherein the gas turbine engine is a two-spool gas turbine engine (Para. [0015] “Low pressure spool 14 and high pressure spool 16 are coaxial, each extending along and rotating about centerline axis 37 independently of one another”) and the auxiliary compressor (74, 91) is located fluidly between a high pressure compressor section (24) of the two-spool gas turbine engine and the combustor (70).
Claim 5 is rejected under 35 U.S.C. 103 as being unpatentable over Hanrahan et al. (2020/0040848A1) in view of Macchia et al. (11,352,954) in view of Fath (7,085,644) in further view of Mizukami et al. (10,352,243).
Re Claim 5, Hanrahan, i.v., Maccia and Fath, teaches the invention as claimed and as discussed above; except, further comprising a compressor valve operable to allow the airflow to selectably bypass the auxiliary compressor while still directing the airflow through the intercooler heat exchanger.
Mizukami teaches, in Figs. 2 and 4 - 9, a similar gas turbine (11-12-13) including a compressor valve (36) operable to allow the airflow to selectably bypass an auxiliary compressor (bypassing 31, 40 and flowing 28 straight to combustor 12).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify Hanrahan, i.v., Maccia and Fath, with the compressor valve operable to allow the airflow to selectably bypass an auxiliary compressor, taught by Mizukami, because all the claimed elements, i.e., the gas turbine engine having a compressor section, combustor, and turbine section in serial fluid flow arrangement, an auxiliary compressor disposed fluidly between the compressor section and the combustor such that an airflow exiting the compressor section is directed toward the auxiliary compressor, the auxiliary compressor driven independently from the compressor section and configured to output the airflow toward the combustor; an intercooler heat exchanger disposed fluidly between the compressor section and the auxiliary compressor, and a compressor valve operable to allow the airflow to selectably bypass an auxiliary compressor, were known in the art, in combination each one of the components would perform the same function as it did separately, and one skilled in the art could have combined the elements as claimed by known methods, with no change in their respective functions, to yield predictable results, i.e., integrating the compressor valve in the airflow line downstream of said intercooler heat exchanger and upstream of said auxiliary compressor would have facilitated selectably bypassing the auxiliary compressor while still directing the airflow through the intercooler heat exchanger and then to the combustor when further compression of said airflow by said auxiliary compressor was not required. KSR, 550 U.S. 398 (2007), 82 USPQ2d at 1395; MPEP 2143(A).
Claims 9 and 19 are rejected under 35 U.S.C. 103 as being unpatentable over Hanrahan et al. (2020/0040848A1) in view of Macchia et al. (11,352,954) in view of Fath (7,085,644) in further view of Brostmeyer et al. (2016/0215694A1).
Re Claims 9 and 19, Hanrahan, i.v., Maccia and Fath, teaches the invention as claimed and as discussed above; except, (Claim 9) wherein the turbine section includes a variable pitch vane stage and (Claim 19) further comprising operating a variable pitch vane stage at the turbine section to control the combustion products entering the turbine section.
Brostmeyer teaches, in Figs. 5 – 7 and 9, a similar gas turbine engine having a turbine section (61 – Figs. 5 – 7, 91 – Fig. 9) includes a variable pitch vane stage (63 – Figs. 5 – 7, 93 – Fig. 9).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify Hanrahan, i.v., Maccia and Fath, with the variable pitch vane stage in the turbine section, taught by Brostmeyer, to facilitate controlling the flow of combustion gases through the turbine section to facilitate a better match between the rotational speeds of the low pressure compressor and the high pressure compressor (Para. [0053]).
Response to Arguments
Applicant's arguments filed 01/06/2026 have been fully considered and to the extent possible have been addressed in the rejections above, at the appropriate locations.
Correspondence
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/LORNE E MEADE/Primary Examiner, Art Unit 3741