FINAL 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 .
This is the sixth office action on the merits. This office action is in response to the amendment filed on 05/11/2026. Applicant has amended claims 1, 5, 8, and 14 and cancelled claim 4. Claims 1, 5, 8-10, 12-14, 17, and 19-20 are pending and examined.
Claim Objections
Claim 14 is objected to under 37 CFR 1.121(c) because “in the claim listing, the status of every claim must be indicated after its claim number by using one of the following identifiers in a parenthetical expression: (Original), (Currently amended), (Canceled), (Withdrawn), (Previously presented), (New), and (Not entered)”. Claim 14 should have been listed as “currently amended”.
Claims 1, 5, 8-10, and 12-14 are objected to because of the following informalities:
Claim 1, lines 7-8: “the high pressure compressor sixth stage, seventh stage, eighth stage, and tenth stage” lacks antecedent basis, and should be rewritten as --a sixth stage, a seventh stage, an eighth stage, and a tenth stage of the high pressure compressor--
Claim 5, lines 3-5: “the high pressure compressor third stage and fourth stage” lacks antecedent basis, and should be rewritten as --a third stage and a fourth stage of the high pressure compressor--
Claim 8, lines 10-11: “the high pressure compressor third stage and fourth stage” lacks antecedent basis, and should be rewritten as --a third stage and a fourth stage of the high pressure compressor--
Claims 9-10 and 12-13, lines 1-2: “The gas turbine engine with an electrically boosted cooling air system” is believed to be in error for --The gas turbine engine with the electrically boosted cooling air system-- (see claim 8, lines 1-2)
Claim 14, lines 7-9: “the high pressure compressor, third stage, fourth stage, sixth stage, seventh stage, eighth stage, and tenth stage” lacks antecedent basis, and should be rewritten as --a third stage, a fourth stage, a sixth stage, a seventh stage, an eighth stage, and a tenth stage of the high pressure compressor--
Appropriate correction is required.
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.
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, 8-10, and 13 are rejected under 35 U.S.C. 103 as being unpatentable over Ortiz (US 2018/0334966 A1), in view of Sennoun (US 2013/0164115 A1), Howarth (US 2021/0172374 A1), and Roberge (US 2019/0353103 A1: IDS reference).
Regarding claim 1, Ortiz teaches (Figure 2) an electrically boosted cooling air system (72 – note that “electrically boosted” is preamble and holds little patentable weight) comprising:
a high pressure compressor (52);
a first cooling air supply line (60a) coupling the high pressure compressor (52) with a high pressure turbine (54, via turbine manifold 68a) and a second cooling air supply line (60b) coupling the high pressure compressor (52) with a low pressure turbine (46, via turbine manifold 68b).
However, Ortiz does not teach said first cooling air supply line is fluidly coupled with at least one of the high pressure compressor sixth stage, seventh stage, eighth stage, and tenth stage.
Sennoun teaches (Fig. 1) a high pressure compressor (106) having a plurality of stages, wherein a first cooling air supply line (118) is fluidly coupled with at least one of the high pressure compressor (106) sixth stage, seventh stage, eighth stage, and tenth stage (via extraction port 119) – (¶ [0022], ll. 8-11: “a high-pressure bleed air line 118, which may be connected to an extraction port 119 approximate a seventh stage of high-pressure compressors 106”).
Howarth teaches (Figure 4) an air bleed passage (43) that bleeds air from the last stage of a high pressure compressor (15). Howarth further teaches the last stage is the stage with the highest pressure of compressed air (¶ [0080], ll. 1-4).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify Ortiz by fluidly coupling said first cooling air supply line with at least one of the high pressure compressor sixth stage, seventh stage, eighth stage, and tenth stage, as taught by Sennoun, because it has been held under the “obvious to try” provision, that choosing from a finite number of identified, predictable solutions (in this case, choosing one out of a finite number of discrete stages within the high pressure compressor from which to bleed air), with a reasonable expectation of success (in this case, to select a specific stage to provide a desired bleed air pressure, such that selecting a higher stage provides a higher bleed air pressure, as taught by Howarth) was an obvious extension of prior art teachings. See KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 415-421, 82 USPQ2d 1385, 1395-97 (2007), MPEP 2143 (I)(E).
However, Ortiz, in view of Sennoun and Howarth, does not teach a first electrically powered fan fluidly coupled with the first cooling air supply line; a second electrically powered fan fluidly coupled with the second cooling air supply line; wherein the first electrically powered fan and the second electrically powered fan are configured to provide at least one of a pressure increase and a flow rate increase for cooling air supplied from the high pressure compressor; wherein said first electrically powered fan and the second electrically powered fan are configured to provide additional cooling air pressure and cooling air flow rate responsive to a predetermined gas turbine engine demand for cooling air, wherein said predetermined gas turbine engine demand for cooling air is selected from the group consisting of a power demand above a cruise operation condition, an off-normal engine operation condition, a certification testing engine operation condition, and a gap in cooling air source pressure.
Roberge teaches (Figure 1) a similar cooling air system (62) for a gas turbine engine (20) comprising:
a high pressure compressor (52);
a first cooling air supply line (68 and 78) coupling the high pressure compressor (52) with a high pressure turbine (54); and
a first electrically powered fan (72 – see ¶ [0038], ll. 1-2: “an auxiliary compressor 72 that is driven by an electric motor 82”, thereby showing 72 is electrically powered. Note that auxiliary compressor 72 functions as a fan because it creates airflow) fluidly coupled with the first cooling air supply line (68 and 78); wherein the first electrically powered fan (72) is configured to provide at least one of a pressure increase and a flow rate increase (¶ [0039]) for cooling air supplied from (at air tap 64) the high pressure compressor (52); wherein said first electrically powered fan (72) is configured to provide additional cooling air pressure and cooling air flow rate (as discussed in ¶ [0039]) responsive to a predetermined gas turbine engine demand for cooling air (¶ [0045], ll. 14-22 – also intended use, see below); wherein said predetermined gas turbine engine demand for cooling air is selected from the group consisting of a power demand above a cruise operation condition, an off-normal engine operation condition (see ¶ [0045], ll. 14-18: “The auxiliary compressor 72 can therefore be operated at speeds tailored to specific operational parameters of the engine 20 including fuel flow, temperature, specific flight profile, engine performance degradation over time”), a certification testing engine operation condition, and a gap in cooling air source pressure (intended use, see below).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify Ortiz, in view of Sennoun and Howarth, by including a first electrically powered fan fluidly coupled with the first cooling air supply line; wherein the first electrically powered fan is configured to provide at least one of a pressure increase and a flow rate increase for cooling air supplied from the high pressure compressor; wherein said first electrically powered fan is configured to provide additional cooling air pressure and cooling air flow rate responsive to a predetermined gas turbine engine demand for cooling air, wherein said predetermined gas turbine engine demand for cooling air is selected from the group consisting of a power demand above a cruise operation condition, an off-normal engine operation condition, a certification testing engine operation condition, and a gap in cooling air source pressure, in order to provide cooled airflow at pressure compatible with current operating conditions in the turbine section, as taught by Roberge (¶ [0042], ll. 5-8).
However, Ortiz, in view of Sennoun, Howarth, and Roberge as discussed so far, does not teach a second electrically powered fan fluidly coupled with the second cooling air supply line; wherein the second electrically powered fan is configured to provide at least one of a pressure increase and a flow rate increase for cooling air supplied from the high pressure compressor; wherein the second electrically powered fan is configured to provide additional cooling air pressure and cooling air flow rate responsive to a predetermined gas turbine engine demand for cooling air.
Roberge further teaches “cooled cooling air could be provided to any portion within the turbine section 28 including the low pressure turbine 46 or other components within the engine 20 that require cooled cooling air” (¶ [0040], ll. 8-11).
Since Roberge already teaches a first electrically powered fan (72) for providing cooled cooling air from the high pressure compressor (52) to the high pressure turbine (54), another electrically powered fan would be needed to additionally provide cooled cooling air from the high pressure compressor (52) to the low pressure turbine (46) when modifying the two cooling air supply lines of Ortiz.
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify Ortiz, in view of Sennoun, Howarth, and Roberge as discussed so far, by including a second electrically powered fan fluidly coupled with the second cooling air supply line; wherein the second electrically powered fan is configured to provide at least one of a pressure increase and a flow rate increase for cooling air supplied from the high pressure compressor; wherein the second electrically powered fan is configured to provide additional cooling air pressure and cooling air flow rate responsive to a predetermined gas turbine engine demand for cooling air, in order to provide cooled cooling air to any portion within the turbine section that requires cooled cooling air, including the low pressure turbine, as taught by Roberge (¶ [0040], ll. 8-11).
Note that the above modifications result in adding a first electrically powered fan to Ortiz’s first cooling air supply line (60a) and a second electrically powered fan to Ortiz’s second cooling air supply line (60b) per Roberge’s teaching of an electrically powered fan located in an analogous cooling air supply line.
The recitation “configured to provide additional cooling air pressure and cooling air flow rate responsive to a predetermined gas turbine engine demand for cooling air, wherein said predetermined gas turbine engine demand for cooling air is selected from the group consisting of a power demand above a cruise operation condition, an off-normal engine operation condition, a certification testing engine operation condition, and a gap in cooling air source pressure” is a statement of intended use and the structure of the device as taught Ortiz, in view of Sennoun, Howarth, and Roberge, can perform the function. It has been held that “[A]pparatus claims cover what a device is, not what a device does.” Hewlett-Packard Co. v. Bausch & Lomb Inc., 909 F.2d 1464, 1469, 15 USPQ2d 1525, 1528 (Fed. Cir. 1990) (emphasis in original); MPEP 2114.
It has also been held that, “Where the claimed and prior art products are identical or substantially identical in structure or composition, or are produced by identical or substantially identical processes, a prima facie case of either anticipation or obviousness has been established.” In re Best, 562 F.2d 1252, 1255, 195 USPQ 430, 433 (CCPA 1977); MPEP 2112.01. A claim containing a “recitation with respect to the manner in which a claimed apparatus is intended to be employed does not differentiate the claimed apparatus from a prior art apparatus” if the prior art apparatus teaches all the structural limitations of the claim. Ex parte Masham, 2 USPQ2d 1647 (Bd. Pat. App. & Inter. 1987); MPEP 2114(II). A recitation of the intended use of the claimed invention must result in a structural difference between the claimed invention and the prior art in order to patentably distinguish the claimed invention from the prior art. The structure of the applied prior art, being similar to the structure of the present application, as claimed and as disclosed, the two structures will obviously function the same way under similar circumstances.
Regarding claim 5, Ortiz, in view of Sennoun, Howarth, and Roberge as discussed so far, teaches the invention as claimed and as discussed above for claim 1, except for the second cooling air supply line is fluidly coupled with at least one of the high pressure compressor third stage and fourth stage.
Sennoun further teaches (Fig. 1) a second cooling air supply line (116) is fluidly coupled with at least one of the high pressure compressor (106) third stage and fourth stage (via extraction port 117) – (¶ [0022], ll. 4-7: “an intermediate-pressure bleed air line 116, which may be connected to an extraction port 117 approximate a fourth stage of high-pressure compressor 106”).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify Ortiz, in view of Sennoun, Howarth, and Roberge as discussed so far, by fluidly coupling the second cooling air supply line with at least one of the high pressure compressor third stage and fourth stage, as taught by Sennoun, for the same reasons as discussed in the rejection of claim 1.
Regarding claim 8, Ortiz teaches (Figure 2) a gas turbine engine (20 – Figure 1) with an electrically boosted cooling air system (72 – note that “electrically boosted” is preamble and holds little patentable weight) comprising:
a high pressure compressor (52);
a first cooling air supply line (60a) fluidly coupled between the high pressure compressor (52) and a high pressure turbine (54, via turbine manifold 68a);
a second cooling air supply line (60b) fluidly coupled between the high pressure compressor (52) and a low pressure turbine (46, via turbine manifold 68b).
However, Ortiz does not teach the second cooling air supply line is fluidly coupled with at least one of the high pressure compressor third stage and fourth stage.
Sennoun teaches (Fig. 1) a high pressure compressor (106) having a plurality of stages, wherein a second cooling air supply line (116) is fluidly coupled with at least one of the high pressure compressor (106) third stage and fourth stage (via extraction port 117) – (¶ [0022], ll. 4-7: “an intermediate-pressure bleed air line 116, which may be connected to an extraction port 117 approximate a fourth stage of high-pressure compressor 106”).
Howarth teaches (Figure 4) an air bleed passage (43) that bleeds air from the last stage of a high pressure compressor (15). Howarth further teaches the last stage is the stage with the highest pressure of compressed air (¶ [0080], ll. 1-4).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify Ortiz by fluidly coupling the second cooling air supply line with at least one of the high pressure compressor third stage and fourth stage, as taught by Sennoun, because it has been held under the “obvious to try” provision, that choosing from a finite number of identified, predictable solutions (in this case, choosing one out of a finite number of discrete stages within the high pressure compressor from which to bleed air), with a reasonable expectation of success (in this case, to select a specific stage to provide a desired bleed air pressure, such that selecting a higher stage provides a higher bleed air pressure, as taught by Howarth) was an obvious extension of prior art teachings. See KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 415-421, 82 USPQ2d 1385, 1395-97 (2007), MPEP 2143 (I)(E).
However, Ortiz, in view of Sennoun and Howarth, does not teach an electrically powered fan fluidly coupled with at least one of the first cooling air supply line and the second cooling air supply line; wherein the electrically powered fan is configured to provide at least one of a pressure increase and a flow rate increase for cooling air supplied from the high pressure compressor; wherein the electrically powered fan is fluidly coupled with the first cooling air supply line.
Roberge teaches (Figure 1) a similar cooling air system (62) for a gas turbine engine (20) comprising:
a high pressure compressor (52);
a first cooling air supply line (68 and 78) coupled between the high pressure compressor (52) and the high pressure turbine (54); and
an electrically powered fan (72 – see ¶ [0038], ll. 1-2: “an auxiliary compressor 72 that is driven by an electric motor 82”, thereby showing 72 is electrically powered. Note that auxiliary compressor 72 functions as a fan because it creates airflow) fluidly coupled with the first cooling air supply line (68 and 78); wherein the electrically powered fan (72) is configured to provide at least one of a pressure increase and a flow rate increase (¶ [0039]) for cooling air supplied from (at air tap 64) the high pressure compressor (52); wherein the electrically powered fan (72) is fluidly coupled with the first cooling air supply line (68 and 78).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify Ortiz, in view of Sennoun and Howarth, by including an electrically powered fan fluidly coupled with the at least one cooling air supply line; wherein the electrically powered fan is configured to provide at least one of a pressure increase and a flow rate increase for cooling air supplied from the high pressure compressor; wherein the electrically powered fan is fluidly coupled with the first cooling air supply line, in order to provide cooled airflow at pressure compatible with current operating conditions in the turbine section, as taught by Roberge (¶ [0042], ll. 5-8).
However, Ortiz, in view of Sennoun, Howarth, and Roberge as discussed so far, does not teach another electrically powered fan is fluidly coupled with the second cooling air supply line.
Roberge further teaches “cooled cooling air could be provided to any portion within the turbine section 28 including the low pressure turbine 46 or other components within the engine 20 that require cooled cooling air” (¶ [0040], ll. 8-11).
Since Roberge already teaches an electrically powered fan (72) for providing cooled cooling air from the high pressure compressor (52) to the high pressure turbine (54), another electrically powered fan would be needed to additionally provide cooled cooling air from the high pressure compressor (52) to the low pressure turbine (46) when modifying the two cooling air supply lines of Ortiz.
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify Ortiz, in view of Sennoun, Howarth, and Roberge as discussed so far, by including another electrically powered fan being fluidly coupled with the second cooling air supply line, in order to provide cooled cooling air to any portion within the turbine section that requires cooled cooling air, including the low pressure turbine, as taught by Roberge (¶ [0040], ll. 8-11).
Note that the above modifications result in adding a first electrically powered fan to Ortiz’s first cooling air supply line (60a) and a second electrically powered fan to Ortiz’s second cooling air supply line (60b) per Roberge’s teaching of an electrically powered fan located in an analogous cooling air supply line.
Regarding claim 9, Ortiz, in view of Sennoun, Howarth, and Roberge, teaches the invention as claimed and as discussed above for claim 8, and Ortiz further teaches (Figure 2) at least one of the first cooling air supply line (60a) and the second cooling air supply line (60b) are fluidly coupled with a bleed air source (58a-58d) having a pressure below a predetermined value.
Ortiz, in view of Sennoun, Howarth, and Roberge, further teaches said electrically powered fan (Roberge, 72) is configured to increase the pressure of the cooling air to a predetermined value (Roberge, ¶ [0039], ll. 7-9: “Air flow provided by the air tap 64 is compressed to a higher pressure within the auxiliary compressor 72”).
Regarding claim 10, Ortiz, in view of Sennoun, Howarth, and Roberge as discussed so far, teaches the invention as claimed and as discussed above for claim 8, except for the electrically powered fan being configured to adjust cooling air supply pressure and flow rate requirements responsive to changes in turbine sink pressures, said turbine sink pressures being responsive to variable shaft horsepower extractions due to spool and engine load sharing.
Roberge further teaches (Figure 1) the electrically powered fan (72) is configured to adjust cooling air supply pressure and flow rate requirements responsive to changes in turbine sink pressures, said turbine sink pressures being responsive to variable shaft horsepower extractions due to spool and engine load sharing (intended use – see ¶ [0042], ll. 4-8: “The controller 88 uses the information from the FADEC 96 to determine the speed at which the auxiliary compressor 72 should be driven to provide cooled airflow at pressure compatible with current operating conditions in the turbine section 28”).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify Ortiz, in view of Sennoun, Howarth, and Roberge as discussed so far, by configuring the electrically powered fan to adjust cooling air supply pressure and flow rate requirements responsive to changes in turbine sink pressures, said turbine sink pressures being responsive to variable shaft horsepower extractions due to spool and engine load sharing, for the same reasons as discussed in the rejection of claim 8.
The recitation “configured to adjust cooling air supply pressure and flow rate requirements responsive to changes in turbine sink pressures, said turbine sink pressures being responsive to variable shaft horsepower extractions due to spool and engine load sharing” is a statement of intended use and the structure of the device as taught Ortiz, in view of Sennoun, Howarth, and Roberge, can perform the function due to the presence of controller 88, which is configured to operate fan 72 in response to engine data received via FADEC 96. It has been held that “[A]pparatus claims cover what a device is, not what a device does.” Hewlett-Packard Co. v. Bausch & Lomb Inc., 909 F.2d 1464, 1469, 15 USPQ2d 1525, 1528 (Fed. Cir. 1990) (emphasis in original); MPEP 2114.
It has also been held that, “Where the claimed and prior art products are identical or substantially identical in structure or composition, or are produced by identical or substantially identical processes, a prima facie case of either anticipation or obviousness has been established.” In re Best, 562 F.2d 1252, 1255, 195 USPQ 430, 433 (CCPA 1977); MPEP 2112.01. A claim containing a “recitation with respect to the manner in which a claimed apparatus is intended to be employed does not differentiate the claimed apparatus from a prior art apparatus” if the prior art apparatus teaches all the structural limitations of the claim. Ex parte Masham, 2 USPQ2d 1647 (Bd. Pat. App. & Inter. 1987); MPEP 2114(II). A recitation of the intended use of the claimed invention must result in a structural difference between the claimed invention and the prior art in order to patentably distinguish the claimed invention from the prior art. The structure of the applied prior art, being similar to the structure of the present application, as claimed and as disclosed, the two structures will obviously function the same way under similar circumstances.
Regarding claim 13, Ortiz, in view of Sennoun, Howarth, and Roberge as discussed so far, teaches the invention as claimed and as discussed above for claim 8, except for the electrically powered fan being configured to operate during a hot shutdown engine condition to provide ventilation to the gas turbine engine.
Roberge further teaches (Figure 1) the electrically powered fan (72) is configured to operate during a hot shutdown engine condition to provide ventilation to a gas turbine engine (20) – (intended use, see below).
The recitation “being configured to operate during a hot shutdown engine condition to provide ventilation to the gas turbine engine” is a statement of intended use and the structure of the device as taught Ortiz, in view of Sennoun, Howarth, and Roberge, can perform the function. It has been held that “[A]pparatus claims cover what a device is, not what a device does.” Hewlett-Packard Co. v. Bausch & Lomb Inc., 909 F.2d 1464, 1469, 15 USPQ2d 1525, 1528 (Fed. Cir. 1990) (emphasis in original); MPEP 2114.
It has also been held that, “Where the claimed and prior art products are identical or substantially identical in structure or composition, or are produced by identical or substantially identical processes, a prima facie case of either anticipation or obviousness has been established.” In re Best, 562 F.2d 1252, 1255, 195 USPQ 430, 433 (CCPA 1977); MPEP 2112.01. A claim containing a “recitation with respect to the manner in which a claimed apparatus is intended to be employed does not differentiate the claimed apparatus from a prior art apparatus” if the prior art apparatus teaches all the structural limitations of the claim. Ex parte Masham, 2 USPQ2d 1647 (Bd. Pat. App. & Inter. 1987); MPEP 2114(II). A recitation of the intended use of the claimed invention must result in a structural difference between the claimed invention and the prior art in order to patentably distinguish the claimed invention from the prior art. The structure of the applied prior art, being similar to the structure of the present application, as claimed and as disclosed, the two structures will obviously function the same way under similar circumstances.
Claim 12 is rejected under 35 U.S.C. 103 as being unpatentable over Ortiz (US 2018/0334966 A1), in view of Sennoun (US 2013/0164115 A1), Howarth (US 2021/0172374 A1), and Roberge (US 2019/0353103 A1: IDS reference), and in further view of Christopherson (US 2018/0009536 A1).
Regarding claim 12, Ortiz, in view of Sennoun, Howarth, and Roberge, teaches the invention as claimed and as discussed above for claim 8, except for said electrically powered fan being configured to be rotated by the cooling air flowing through at least one of the first cooling air supply line and the second cooling air supply line to generate electrical power.
Christopherson teaches (Figure 2) a fan (38) is configured to be rotated by airflow to generate electrical power (via generator 170 – see also ¶ [0038], ll. 11-13).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify Ortiz, in view of Sennoun, Howarth, and Roberge, by configuring said electrically powered fan to be rotated by the cooling air flowing through at least one of the first cooling air supply line and the second cooling air supply line to generate electrical power, in order to store power and use it to power accessory systems of the aircraft, as taught by Christopherson (¶ [0038], ll. 13-17).
Claims 14 and 17 are rejected under 35 U.S.C. 103 as being unpatentable over Roberge (US 2019/0353103 A1: IDS reference), in view of Sennoun (US 2013/0164115 A1), Howarth (US 2021/0172374 A1), and Chouhan (US 2017/0114647 A1).
Regarding claim 14, Roberge teaches (Figure 1) a process for electrically boosting a gas turbine cooling air system (62 – note that “electrically boosted” is preamble and holds little patentable weight) comprising:
fluidly coupling at least one cooling air supply line (68 and 78) between a high pressure compressor (52) and at least one of a high pressure turbine (54) and a low pressure turbine (46) – (in this case, it is between high pressure compressor 52 and high pressure turbine 54);
fluidly coupling an electrically powered fan (72 – see ¶ [0038], ll. 1-2: “an auxiliary compressor 72 that is driven by an electric motor 82”, thereby showing 72 is electrically powered. Note that auxiliary compressor 72 functions as a fan because it creates airflow) with the at least one cooling air supply line (68 and 78);
providing at least one of a pressure increase and a flow rate increase (¶ [0039]) with the electrically powered fan (72) for cooling air supplied from (at air tap 64) the high pressure compressor (52);
providing additional cooling air pressure and cooling air flow rate (as discussed in ¶ [0039]) with the electrically powered fan (72) responsive to a predetermined gas turbine engine demand for cooling air (¶ [0045], ll. 14-22); wherein said predetermined gas turbine engine demand for cooling air is selected from the group consisting of a power demand above a cruise operation condition; an off-normal engine operation condition (see ¶ [0045], ll. 14-18: “he auxiliary compressor 72 can therefore be operated at speeds tailored to specific operational parameters of the engine 20 including fuel flow, temperature, specific flight profile, engine performance degradation over time”), a certification testing engine operation condition; and a gap in cooling air source pressure.
However, Roberge does not teach the at least one cooling air supply line is fluidly coupled with at least one of the high pressure compressor, third stage, fourth stage, sixth stage, seventh stage, eighth stage, and tenth stage.
Sennoun teaches (Fig. 1) a high pressure compressor (106) having a plurality of stages, wherein at least one cooling air supply line (116 and 118) is fluidly coupled with at least one of the high pressure compressor (106), third stage, fourth stage, sixth stage, seventh stage, eighth stage, and tenth stage (via extraction ports 117 and 119) – (¶ [0022], ll. 4-7: “an intermediate-pressure bleed air line 116, which may be connected to an extraction port 117 approximate a fourth stage of high-pressure compressor 106” and ll. 8-11: “a high-pressure bleed air line 118, which may be connected to an extraction port 119 approximate a seventh stage of high-pressure compressors 106”).
Howarth teaches (Figure 4) an air bleed passage (43) that bleeds air from the last stage of a high pressure compressor (15). Howarth further teaches the last stage is the stage with the highest pressure of compressed air (¶ [0080], ll. 1-4).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify Roberge by fluidly coupling the at least one cooling air supply line with at least one of the high pressure compressor, third stage, fourth stage, sixth stage, seventh stage, eighth stage, and tenth stage, as taught by Sennoun, because it has been held under the “obvious to try” provision, that choosing from a finite number of identified, predictable solutions (in this case, choosing one out of a finite number of discrete stages within the high pressure compressor from which to bleed air), with a reasonable expectation of success (in this case, to select a specific stage to provide a desired bleed air pressure, such that selecting a higher stage provides a higher bleed air pressure, as taught by Howarth) was an obvious extension of prior art teachings. See KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 415-421, 82 USPQ2d 1385, 1395-97 (2007), MPEP 2143 (I)(E).
Roberge further teaches (Figure 1) adjusting a cooling air supply pressure and a flow rate requirement employing said electrically powered fan (72) based on current operating conditions in the turbine section (¶ [0042], ll. 4-8: “The controller 88 uses the information from the FADEC 96 to determine the speed at which the auxiliary compressor 72 should be driven to provide cooled airflow at pressure compatible with current operating conditions in the turbine section 28”), but does not teach doing this during changes in turbine sink pressures.
Chouhan teaches (Figures 2 and 6) a gas turbine engine comprising a turbine section (2), and further teaches:
“the ejection pressure at the hot gas path proximate radially outboard location 428 (referred to as “sink pressure”)” (¶ [0032], ll. 15-17);
“a reduction in the sink pressure can reduce the requirement for higher-pressure cooling fluid at the inlet proximate base 6” (¶ [0032], ll. 19-21); and
“Bucket 2, 302, 402, 802, including outlet path 220 can reduce sink pressure when compared with conventional buckets, thus requiring a lower supply pressure from the compressor to maintain a same pressure ratio. This reduces the work required by the compressor (to compress cooling fluid), and improves efficiency in a gas turbine employing bucket 2, 302, 402, 802 relative to conventional buckets” (¶ [0032], ll. 21-28).
Therefore, in the case of lower sink pressure, the compressor should adjust by lowering the supply pressure of air.
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify Roberge, in view of Sennoun and Howarth, by adjusting a cooling air supply pressure and a flow rate requirement employing said electrically powered fan during changes in turbine sink pressures, in order to reduce the work required by the compressor, thus improving efficiency, as taught by Chouhan (¶ [0032], ll. 25-28), therefore providing:
said turbine sink pressures occurring as a result of variable shaft horsepower extractions due to spool and engine load sharing (desired result – see below).
The recitation “said turbine sink pressures occurring as a result of variable shaft horsepower extractions due to spool and engine load sharing” is a statement of desired result flowing implicitly from a process step of “adjusting a cooling air supply pressure…during changes in turbine sink pressure”. It has been held that a “whereby clause in a method claim is not given weight when it simply expresses the intended result of a process step positively recited.” Id. (quoting Minton v. Nat’l Ass’n of Securities Dealers, Inc., 336 F.3d 1373, 1381, 67 USPQ2d 1614, 1620 (Fed. Cir. 2003)), MPEP 2111.04 (I).
Alternatively, the recitation “providing additional cooling air pressure and cooling air flow rate with the electrically powered fan responsive to a predetermined gas turbine engine demand for cooling air” may be interpreted as a conditional claim limitation that is only required to be performed when the recited condition is met. Consequently, if none of the recited conditions are met, then the claimed method is requiring no steps be performed. “The broadest reasonable interpretation of a method (or process) claim having contingent limitations requires only those steps that must be performed and does not include steps that are not required to be performed because the condition(s) precedent are not met.” See MPEP 2111.04, II. In this case, the claim is not explicitly requiring any steps be performed because the condition (a predetermined gas turbine engine demand for cooling air) is not required to occur.
Regarding claim 17, Roberge, in view of Sennoun, Howarth, and Chouhan, teaches the invention as claimed and as discussed above for claim 14, and Roberge further teaches (Figure 1) fluidly coupling the at least one cooling air supply line (68 and 78) with a bleed air source (64) having a pressure below a predetermined value (pressure of high pressure compressor 52 at air tap 64); and
increasing the pressure of the cooling air to the predetermined value employing said electrically powered fan (72) – (¶ [0039], ll. 7-9: “Air flow provided by the air tap 64 is compressed to a higher pressure within the auxiliary compressor 72”).
Claim 19 is rejected under 35 U.S.C. 103 as being unpatentable over Roberge (US 2019/0353103 A1: IDS reference), in view of Sennoun (US 2013/0164115 A1), Howarth (US 2021/0172374 A1), and Chouhan (US 2017/0114647 A1), and in further view of Christopherson (US 2018/0009536 A1).
Regarding claim 19, Roberge, in view of Sennoun, Howarth, and Chouhan, teaches the invention as claimed and as discussed above for claim 14, except for generating electrical power employing said electrically powered fan configured to be rotated by the cooling air flowing through the at least one cooling air supply line.
Christopherson teaches (Figure 2) generating electrical power (via generator 170 – see also ¶ [0038], ll. 11-13) employing a fan (38) is configured to be rotated by airflow.
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify Roberge, in view of Sennoun, Howarth, and Chouhan, by generating electrical power employing said electrically powered fan configured to be rotated by the cooling air flowing through the at least one cooling air supply line, in order to store power and use it to power accessory systems of the aircraft, as taught by Christopherson (¶ [0038], ll. 13-17).
Claim 20 is rejected under 35 U.S.C. 103 as being unpatentable over Roberge (US 2019/0353103 A1: IDS reference), in view of Sennoun (US 2013/0164115 A1), Howarth (US 2021/0172374 A1), Chouhan (US 2017/0114647 A1), and Christopherson (US 2018/0009536 A1), and in further view of Millhaem (US 2022/0235707 A1).
Regarding claim 20, Roberge, in view of Sennoun, Howarth, Chouhan, and Christopherson, teaches the invention as claimed and as discussed above for claim 19, and Roberge further teaches (Figure 1) providing ventilation (via auxiliary compressor 72) to the gas turbine engine (20).
However, Roberge, in view of Sennoun, Howarth, Chouhan, and Christopherson, does not teach operating the electrically powered fan being during a hot shutdown engine condition.
Millhaem teaches (Figure 2) a similar cooling system (60) comprising an electrically powered fan (76 – see ¶ [0055], ll. 5-6: “the cooling blower 76 includes a rotor 78 carrying a plurality of fan blades” and ¶ [0056], ll. 3-4: “the blower's rotor 78 is coupled to an electric motor 80”, thereby showing 76 is electrically powered), and
operating the electrically powered fan (76) during a hot shutdown engine condition (¶ [0059], ll. 11-14: “(1) operating the cooling blower 76 and (2) opening the valve or valves of the valve assembly 68, at a time during or after a shutdown of the engine 10”).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify Roberge, in view of Sennoun, Howarth, Chouhan, and Christopherson, by operating the electrically powered fan being during a hot shutdown engine condition, in order to lower the respective temperatures of the fuel nozzles and other parts of the core, and to reduce or prevent coking and to reduce or prevent rotor bow, as taught by Millhaem (¶ [0059], ll. 7-10).
Response to Arguments
Applicant’s arguments regarding the new limitations in claims 1, 8, and 14 have been considered but are moot in view of the new ground(s) of rejection, necessitated by Applicant's amendments. To the extent possible, Applicant's arguments have been addressed in the body of the rejections at the appropriate locations.
Applicant's arguments filed Ma, specifically from pages 10-20 have been recycled from prior Applicant-filed “REMARKS/ARGUMENTS”. These arguments have already been addressed in prior office actions (see Non-Final of 02/11/2026 and Final of 04/08/2025) and will not be repeated in this office action.
Applicant’s other arguments (specifically regarding criticality on pages 9 and 22 of “REMARKS/ARGUMENTS”) have been fully considered but are not persuasive.
On page 9 of Applicant’s REMARKS, Applicant specifically referred to paragraph [0041] of the specification to provide criticality for coupling the cooling air supply to a particular stage of the high pressure compressor. However, there is nothing in paragraph [0041] that discusses the benefit of choosing one stage of the compressor over another stage. In fact, the word “stage(s)” is not present in paragraph [0041] at all.
On page 22 of Applicant’s REMARKS, Applicant specifically referred to paragraphs [0045] and [0046] of the specification to provide criticality for coupling the cooling air supply to a particular stage of the high pressure compressor. However, paragraph [0045] merely states “an opportunity to source cooling flows from an earlier stage arises”. Paragraph [0046] similarly discusses boosting “from a lower (and cooler) pressure source”. The prior art is replete with examples of bleeding air off of any stage. For example, Sennoun teaches in paragraph [0022], “Bleed air may be taken from one or more stages of low-pressure compressor 104 and/or high-pressure compressor 106”. Sennoun then provides specific examples of bleed air being taken from the fourth stage, the seventh stage, and the final stage. Howarth teaches in paragraph [0080], “Likewise, the air bleed could be taken from any other location on the high pressure compressor”. There is nothing in paragraphs [0045] and [0046] that discuss a particular benefit of choosing one particular early/low stage over another early/low stage. For example, what is the benefit of choosing to bleed air from the third stage over the fourth stage? It is already known in the prior art that higher stages provide higher pressure bleed air; therefore, a lower stage will provide lower pressure bleed air, and since pressure is directly proportional to temperature, the lower stage will also provide a lower temperature bleed air.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
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/HENRY NG/Examiner, Art Unit 3741 /DEVON C KRAMER/Supervisory Patent Examiner, Art Unit 3741
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