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 second office action on the merits. This office action is in response to the amendment filed on 03/02/2026. Applicant has not made any amendments to the claims. Claims 21-40 are currently pending and being examined.
Claim Objections
Claims 21-22, 32, 34, and 37-38 are objected to because of the following informalities:
Claim 21, line 10: “the liner panel the liner panel including…” is believed to be in error for --
Claim 21, line 20: “a substantial forward direction” is believed to be in error for --a substantially forward direction--
Claim 21, lines 24-25: “a substantial aft direction” is believed to be in error for --a substantially aft direction--
Claim 22, line 2: “the substantial aft direction” is believed to be in error for --the substantially aft direction--
Claim 32, line 15: “a substantial forward direction” is believed to be in error for --a substantially forward direction--
Claim 32, lines 19-20: “a substantial aft direction” is believed to be in error for --a substantially aft direction--
Claim 34, line 2: “the substantial aft direction” is believed to be in error for --the substantially aft direction--
Claim 37, line 10: “the liner panel the liner panel including…” is believed to be in error for --
Claim 37, line 22: “a substantial forward direction” is believed to be in error for --a substantially forward direction--
Claim 37, lines 26-27: “a substantial aft direction” is believed to be in error for --a substantially aft direction--
Claim 38, line 2: “the substantial aft direction” is believed to be in error for --the substantially aft direction--
Appropriate correction is required.
Terminal Disclaimer
The terminal disclaimer filed on March 2, 2026 disclaiming the terminal portion of any patent granted on this application which would extend beyond the expiration date of U.S. Patent No. 12,247,738 has been reviewed and is accepted. The terminal disclaimer has been recorded.
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 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.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 21-23, 25, and 29-34 are rejected under 35 U.S.C. 103 as being unpatentable over Bronson (US 9,897,320 B2: IDS reference), in view of Tu (US 2016/0169515 A1) and Dudebout (US 2009/0084110 A1: IDS reference).
Regarding claim 21, Bronson teaches (Figs. 2 and 3) a combustor (124 – Fig. 2) for a gas turbine engine (100 – Fig. 1), the combustor (124) comprising:
an inner shell (210 – Fig. 2) and an outer shell (218 – Fig. 2) extending circumferentially about an axis (coaxial with low pressure spool 138 – Fig. 1), the inner shell (210) and the outer shell (218) forming a combustion chamber (228 – Fig. 2) of the combustor (124) radially between the inner shell (210) and the outer shell (218);
a bulkhead (206 – Fig. 2) extending between the inner shell (210) and the outer shell (218); and
a liner panel (216) mounted on the inner shell (210) or the outer shell (218), the liner panel (216) extending radially between an inner surface (Fig. 2: bottom surface of 216) and an outer surface (Fig. 2: top surface of 216), the inner surface further forming the combustion chamber (228), the liner panel (216) extending axially (shown by axial line 314) between a forward end (224 – Fig. 3) and an aft end (226 – Fig. 3), the liner panel the liner panel (216) including a first section and a second section (see annotated Fig. 3 on next page),
the first section including a first plurality of effusion holes (304) extending through the liner panel (216) from the inner surface to the outer surface, the first plurality of effusion cooling holes (304) including a first portion, a second portion, and a third portion of the first plurality of effusion cooling holes (see annotated Fig. 3 on next page),
effusion holes (304) of the first portion extending in a substantially circumferential direction (as shown in annotated Fig. 3 on next page, effusion holes 304 in the first portion extend horizontally),
effusion holes (304) of the second portion disposed axially forward of the effusion holes (304) of the first portion, the effusion holes (304) of the second portion transitioning from the substantially circumferential direction toward a substantial forward direction as an axial distance from the effusion holes (304) of the first portion increases (as shown in annotated Fig. 3 on next page, effusion holes 304 in the second portion transition from extending horizontally to vertically when proceeding axially from the first portion to the second portion), and
effusion holes (304) of the third portion disposed axially aft of the effusion holes (304) of the first portion, the effusion holes (304) of the third portion transitioning from the substantially circumferential direction toward a substantial aft direction as an axial distance from the effusion holes (304) of the first portion increases (as shown in annotated Fig. 3 on next page, effusion holes 304 in the third portion transition from extending horizontally to vertically when proceeding axially from the first portion to the third portion), and
the second section disposed axially between the first section and the aft end (as shown in annotated Fig. 3 on next page), the second section including a second plurality of effusion holes (304) extending through the liner panel (216) from the inner surface to the outer surface.
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However, Bronson does not teach the first section disposed at the forward end, and
effusion holes of the second portion disposed axially between the forward end and the effusion holes of the first portion.
As shown in annotated Fig. 3 of Bronson above, the second portion (which is part of the first section) does not extend to the forward end.
Bronson further teaches “the substantially transversely disposed effusion cooling holes 304 in each of the initial rows 306, 316 serve to establish a cooling film on the liner inner surfaces. The transition of the effusion cooling holes 304 from the substantially transverse tangential angle (αT) to the substantially axial tangential angle (αT) encourages cooling air flow in the downstream direction, which provides continued effective cooling of the liner inner surfaces while mitigating the swirl component of the upstream effusion cooling holes 304” (col. 5, l. 60 – col. 6, l. 2). Therefore, the tangential angle (αT), and thus the orientation, of the effusion cooling holes is a result-effective variable, i.e., a variable which achieves a recognized result. In re Antonie, 559 F.2d 618, 195 USPQ 6 (CCPA 1977); MPEP 2144.05(II)(B).
In this case, the recognized result is that the tangential angle (αT), and thus the orientation, of the effusion cooling holes can be varied in a design stage in order to provide one of two desired results: (1) a cooling film on the liner inner surface, or (2) continued effective cooling of the liner surfaces while mitigating the swirl component of the upstream effusion cooling holes.
Therefore, since the general conditions of the claim, i.e. that the tangential angle (αT), and thus the orientation, of the effusion cooling holes can be varied in a design stage in order to provide one of two desired results (as discussed above), were disclosed in the prior art by Bronson, it is not inventive to discover the optimum workable pattern of effusion holes in a specific orientation, and it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to vary the tangential angle (αT), and thus the orientation, of the effusion cooling holes in the region between the above annotated “Second portion” and the forward end to have a tangential angle of substantially 0° (i.e., within 5 degrees of 0°), thus extending in a substantial forward direction, as taught by Bronson, in order to provide continued effective cooling of the liner surfaces in this region (Bronson, col. 5, ll. 66-67), thereby allowing the pattern of effusion holes to accommodate, prevent or decrease thermal growth, stress and strain in a dual wall combustor (Bronson, col. 6, ll. 47-56). It has been held that “[W]here the general conditions of a claim are disclosed 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); MPEP 2144.05(II)(A).
Note that the above modification changes all effusion holes 304 in the region between the above annotated “Second portion” and forward end 224 to have the same orientation as the effusion holes of the “Second portion”, thereby extending the “Second portion” to forward end 224, and thus providing:
the first section disposed at the forward end, and
effusion holes of the second portion disposed axially between the forward end and the effusion holes of the first portion.
Additionally, Applicant has failed to provide evidence of criticality for having the effusion holes of the second portion disposed axially between the forward end and the effusion holes of the first portion, such that the effusion holes at the forward end are oriented in a substantially forward direction.
However, Bronson does not teach the second plurality of effusion holes having a greater effusion hole density than the first plurality of effusion holes.
Tu teaches (Figs. 2 and 4A) a similar combustor (100 – Fig. 2) comprising a liner panel (106), the liner panel (106) including a first section (Fig. 4A: comprising effusion holes 134) including a first plurality of effusion holes (134) and a second section (Fig. 4A: comprising effusion holes 144) including a second plurality of effusion holes (144),
the first section (134) disposed at a forward end (140), and
the second section (146) disposed axially between the first section (134) and an aft end (142) – (note that ¶ [0050], ll. 5-6 teaches “in an alternative to FIG. 4A, the edge 142 may be a trailing edge”. In this case, the edge 140 will be a leading edge or a forward end, and edge 142 will be a trailing edge or an aft end), and Tu further teaches:
the second plurality of effusion holes (144) having a greater effusion hole density than the first plurality of effusion holes (134) – (as shown in Fig. 4A and as stated in ¶ [0050], ll. 1-5).
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 Bronson such that the second plurality of effusion holes has a greater effusion hole density than the first plurality of effusion holes, in order to accommodate a greater cooling load at the trailing edge, or aft end, of the liner panel, as taught by Tu (¶ [0050], ll. 2-3).
Additionally, Dudebout teaches (Fig. 2) a similar liner panel (112) comprising effusion holes (150). Specifically, Dudebout teaches “The density of the third group 212 can particularly vary to provide the most effective cooling pattern” (¶ [0028], ll. 10-12). Therefore, the density of effusion cooling holes within a given region of the liner panel is a result-effective variable, i.e., a variable which achieves a recognized result. In re Antonie, 559 F.2d 618, 195 USPQ 6 (CCPA 1977); MPEP 2144.05(II)(B).
In this case, the recognized result is that the density of effusion cooling holes within a given region of the liner panel can be varied in a design stage in order to provide the most effective cooling pattern.
Therefore, since the general conditions of the claim, i.e. that the density of effusion cooling holes within a given region of the liner panel can be varied in a design stage in order to provide the most effective cooling pattern, were disclosed in the prior art by Dudebout, it is not inventive to discover the optimum workable pattern of effusion holes having a specific density within a given region, and it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to vary the second plurality of effusion holes to have a greater effusion hole density than the first plurality of effusion holes, as taught by Dudebout, in order to overcome the increased convective heating of the hot gases accelerating towards the turbine (¶ [0028], ll. 16-19). It has been held that “[W]here the general conditions of a claim are disclosed 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); MPEP 2144.05(II)(A).
Regarding claim 22, Bronson, in view of Tu and Dudebout, teaches the invention as claimed and as discussed above for claim 21, and Bronson further teaches (Fig. 3) each of the second plurality of effusion holes (see annotated Fig. 3 on page 7) extends in the substantial aft direction from the outer surface to the inner surface (as shown in annotated Fig. 3, these holes extend in the vertical, or aft direction).
Regarding claim 23, Bronson, in view of Tu and Dudebout as discussed so far, teaches the invention as claimed and as discussed above for claim 21, except for the second section circumferentially interrupts the first section at the effusion holes of the third portion.
As stated in the rejection of claim 21, Dudebout teaches that the density of effusion cooling holes within a given region of the liner panel is a result-effective variable that can be varied in a design stage in order to provide the most effective cooling pattern.
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 Bronson, in view of Tu and Dudebout as discussed so far, by extending the second section (which has a greater effusion hole density than the first section) to circumferentially interrupt the first section at the effusion holes of the third portion, in order to provide the most effective cooling pattern, as taught by Dudebout (¶ [0028], ll. 10-12).
Regarding claim 25, Bronson, in view of Tu and Dudebout, teaches the invention as claimed and as discussed above for claim 21, and Bronson further teaches (Fig. 2) the forward end (220) is axially adjacent the bulkhead (206).
Regarding claim 29, Bronson, in view of Tu and Dudebout, teaches the invention as claimed and as discussed above for claim 21, and Bronson further teaches (Fig. 3) effusion holes (304) of the third portion (see annotated Fig. 3 on page 7) form a plurality of axial effusion hole rows (as shown in annotated Fig. 3, the third portion contains eight axial effusion hole rows), and effusion holes (304) of each of the plurality of axial effusion hole rows, proceeding in an axially aft direction (toward downstream end 226), are directed increasingly toward the substantially aft direction and increasingly away from the substantially circumferential direction (as shown in annotated Fig. 3, the effusion holes in the bottom row of 322 start off in the circumferential direction and transition to the aft direction as one approaches the top row of 322).
Regarding claim 30, Bronson, in view of Tu and Dudebout, teaches the invention as claimed and as discussed above for claim 21, and Bronson further teaches (Fig. 2) the liner panel (216) is mounted on the inner shell (210) – (note that col. 4, ll. 51-54 teaches “although the outer liner 204 is depicted in FIG. 3, it will be appreciated that the inner liner 202 is typically configured to include similarly arranged effusion cooling holes sets”).
Regarding claim 31, Bronson, in view of Tu and Dudebout, teaches the invention as claimed and as discussed above for claim 21, and Bronson further teaches (Fig. 2) the liner panel (216) is mounted on the outer shell (218).
Regarding claim 32, Bronson teaches (Figs. 2 and 3) a method for convectively cooling a liner panel (216) of a combustor (124 – Fig. 2) for a gas turbine engine (100 – Fig. 1) having an axis (coaxial with low pressure spool 138 – Fig. 1), the liner panel (216) extending between an inner surface (Fig. 2: bottom surface of 216) and an outer surface (Fig. 2: top surface of 216), the inner surface forming a combustion chamber (228 – Fig. 2) of the combustor (124), the liner panel (216) extending axially (shown by axial line 314) between a forward end (224 – Fig. 3) and an aft end (226 – Fig. 3), the method comprising:
convectively cooling the liner panel (216) by directing a cooling air through a first plurality of effusion holes (304 – see annotated Fig. 3 on page 14) formed through the liner panel (216) from the inner surface to the outer surface, the first plurality of effusion cooling holes (304) including a first portion, a second portion, and a third portion of the first plurality of effusion cooling holes (see annotated Fig. 3 on page 14),
effusion holes (304) of the first portion extending in a substantially circumferential direction (as shown in annotated Fig. 3 on next page, effusion holes 304 in the first portion extend horizontally),
effusion holes (304) of the second portion disposed axially forward of the effusion holes (304) of the first portion, the effusion holes (304) of the second portion transitioning from the substantially circumferential direction toward a substantial forward direction as an axial distance from the effusion holes (304) of the first portion increases (as shown in annotated Fig. 3 on next page, effusion holes 304 in the second portion transition from extending horizontally to vertically when proceeding axially from the first portion to the second portion), and
effusion holes (304) of the third portion disposed axially aft of the effusion holes (304) of the first portion, the effusion holes (304) of the third portion transitioning from the substantially circumferential direction toward a substantial aft direction as an axial distance from the effusion holes (304) of the first portion increases (as shown in annotated Fig. 3 on next page, effusion holes 304 in the third portion transition from extending horizontally to vertically when proceeding axially from the first portion to the third portion), and
convectively cooling the liner panel (216) by directing the cooling air through a second plurality of effusion holes (304 – see annotated Fig. 3 on next page) formed through the liner panel (216) from the inner surface to the outer surface, the second plurality of effusion holes disposed downstream (Fig. 3: up direction) of the effusion holes of the third portion (as shown in annotated Fig. 3 on next page).
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However, Bronson does not teach effusion holes of the second portion disposed axially between the forward end and the effusion holes of the first portion.
As shown in annotated Fig. 3 of Bronson above, the second portion does not extend to the forward end.
Bronson further teaches “the substantially transversely disposed effusion cooling holes 304 in each of the initial rows 306, 316 serve to establish a cooling film on the liner inner surfaces. The transition of the effusion cooling holes 304 from the substantially transverse tangential angle (αT) to the substantially axial tangential angle (αT) encourages cooling air flow in the downstream direction, which provides continued effective cooling of the liner inner surfaces while mitigating the swirl component of the upstream effusion cooling holes 304” (col. 5, l. 60 – col. 6, l. 2). Therefore, the tangential angle (αT), and thus the orientation, of the effusion cooling holes is a result-effective variable, i.e., a variable which achieves a recognized result. In re Antonie, 559 F.2d 618, 195 USPQ 6 (CCPA 1977); MPEP 2144.05(II)(B).
In this case, the recognized result is that the tangential angle (αT), and thus the orientation, of the effusion cooling holes can be varied in a design stage in order to provide one of two desired results: (1) a cooling film on the liner inner surface, or (2) continued effective cooling of the liner surfaces while mitigating the swirl component of the upstream effusion cooling holes.
Therefore, since the general conditions of the claim, i.e. that the tangential angle (αT), and thus the orientation, of the effusion cooling holes can be varied in a design stage in order to provide one of two desired results (as discussed above), were disclosed in the prior art by Bronson, it is not inventive to discover the optimum workable pattern of effusion holes in a specific orientation, and it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to vary the tangential angle (αT), and thus the orientation, of the effusion cooling holes in the region between the above annotated “Second portion” and the forward end to have a tangential angle of substantially 0° (i.e., within 5 degrees of 0°), thus extending in a substantial forward direction, as taught by Bronson, in order to provide continued effective cooling of the liner surfaces in this region (Bronson, col. 5, ll. 66-67), thereby allowing the pattern of effusion holes to accommodate, prevent or decrease thermal growth, stress and strain in a dual wall combustor (Bronson, col. 6, ll. 47-56). It has been held that “[W]here the general conditions of a claim are disclosed 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); MPEP 2144.05(II)(A).
Note that the above modification changes all effusion holes 304 in the region between the above annotated “Second portion” and forward end 224 to have the same orientation as the effusion holes of the “Second portion”, thereby extending the “Second portion” to forward end 224, and thus providing:
effusion holes of the second portion disposed axially between the forward end and the effusion holes of the first portion.
Additionally, Applicant has failed to provide evidence of criticality for having the effusion holes of the second portion disposed axially between the forward end and the effusion holes of the first portion, such that the effusion holes at the forward end are oriented in a substantially forward direction.
However, Bronson does not teach the second plurality of effusion holes having a greater effusion hole density than the first plurality of effusion holes.
Tu teaches (Figs. 2 and 4A) a similar combustor (100 – Fig. 2) comprising a liner panel (106), the liner panel (106) including a first section (Fig. 4A: comprising effusion holes 134) including a first plurality of effusion holes (134) and a second section (Fig. 4A: comprising effusion holes 144) including a second plurality of effusion holes (144),
the first section (134) disposed at a forward end (140), and
the second section (146) disposed axially between the first section (134) and an aft end (142) – (note that ¶ [0050], ll. 5-6 teaches “in an alternative to FIG. 4A, the edge 142 may be a trailing edge”. In this case, the edge 140 will be a leading edge or a forward end, and edge 142 will be a trailing edge or an aft end), and Tu further teaches:
the second plurality of effusion holes (144) having a greater effusion hole density than the first plurality of effusion holes (134) – (as shown in Fig. 4A and as stated in ¶ [0050], ll. 1-5).
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 Bronson such that the second plurality of effusion holes has a greater effusion hole density than the first plurality of effusion holes, in order to accommodate a greater cooling load at the trailing edge, or aft end, of the liner panel, as taught by Tu (¶ [0050], ll. 2-3).
Additionally, Dudebout teaches (Fig. 2) a similar liner panel (112) comprising effusion holes (150). Specifically, Dudebout teaches “The density of the third group 212 can particularly vary to provide the most effective cooling pattern” (¶ [0028], ll. 10-12). Therefore, the density of effusion cooling holes within a given region of the liner panel is a result-effective variable, i.e., a variable which achieves a recognized result. In re Antonie, 559 F.2d 618, 195 USPQ 6 (CCPA 1977); MPEP 2144.05(II)(B).
In this case, the recognized result is that the density of effusion cooling holes within a given region of the liner panel can be varied in a design stage in order to provide the most effective cooling pattern.
Therefore, since the general conditions of the claim, i.e. that the density of effusion cooling holes within a given region of the liner panel can be varied in a design stage in order to provide the most effective cooling pattern, were disclosed in the prior art by Dudebout, it is not inventive to discover the optimum workable pattern of effusion holes having a specific density within a given region, and it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to vary the second plurality of effusion holes to have a greater effusion hole density than the first plurality of effusion holes, as taught by Dudebout, in order to overcome the increased convective heating of the hot gases accelerating towards the turbine (¶ [0028], ll. 16-19). It has been held that “[W]here the general conditions of a claim are disclosed 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); MPEP 2144.05(II)(A).
Regarding claim 33, Bronson, in view of Tu and Dudebout, teaches the invention as claimed and as discussed above for claim 32, and Bronson further teaches (Fig. 3) each of the second plurality of effusion holes (see annotated Fig. 3 on page 14) extends in a same direction from the outer surface to the inner surface (as shown in annotated Fig. 3, these holes all extend in a same vertical, or aft direction).
Regarding claim 34, Bronson, in view of Tu and Dudebout, teaches the invention as claimed and as discussed above for claim 33, and Bronson further teaches (Fig. 3) each of the second plurality of effusion holes (see annotated Fig. 3 on page 14) extends in the substantially aft direction from the outer surface to the inner surface (as shown in annotated Fig. 3, these holes extend in the vertical, or aft direction).
Claims 24, 26, and 35 are rejected under 35 U.S.C. 103 as being unpatentable over Bronson (US 9,897,320 B2: IDS reference), in view of Tu (US 2016/0169515 A1) and Dudebout (US 2009/0084110 A1: IDS reference), and in further view of Cunha (US 2016/0273772 A1: IDS reference).
Regarding claim 24, Bronson, in view of Tu and Dudebout, teaches the invention as claimed and as discussed above for claim 21, except for effusion holes of the second portion are oriented toward the bulkhead in a direction from the outer surface to the inner surface.
Cunha teaches (Fig. 6) a similar liner panel (128) comprising effusion holes (150) that are oriented toward a bulkhead (74) in a direction from an outer surface (122) to an inner surface (126).
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 Bronson, in view of Tu and Dudebout, such that effusion holes of the second portion are oriented toward the bulkhead in a direction from the outer surface to the inner surface, in order to provide impingement cooling to the bulkhead, and thereby permit the temperature within an upstream portion of the combustion chamber to be increased to increase turbine engine efficiency and power without substantially increasing NOx, CO and unburned hydrocarbon (UHC) emissions of the turbine engine, as taught by Cunha (¶ [0067], ll. 4-6 and 10-15).
Regarding claim 26, Bronson, in view of Tu and Dudebout, teaches the invention as claimed and as discussed above for claim 21, and Bronson further teaches (Fig. 2) a heat shield panel (see annotated Fig. 2 on next page) mounted to the bulkhead (206).
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However, Bronson, in view of Tu and Dudebout, does not teach effusion holes of the second portion oriented toward the heat shield panel in a direction from the outer surface to the inner surface.
Cunha teaches (Fig. 6) a similar liner panel (128) comprising effusion holes (150) that are oriented toward a heat shield panel (154) of a bulkhead (74) in a direction from an outer surface (122) to an inner surface (126).
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 Bronson, in view of Tu and Dudebout, such that effusion holes of the second portion are oriented toward the heat shield panel in a direction from the outer surface to the inner surface, in order to provide impingement cooling to the bulkhead, and thereby permit the temperature within an upstream portion of the combustion chamber to be increased to increase turbine engine efficiency and power without substantially increasing NOx, CO and unburned hydrocarbon (UHC) emissions of the turbine engine, as taught by Cunha (¶ [0067], ll. 4-6 and 10-15).
Regarding claim 35, Bronson, in view of Tu and Dudebout, teaches the invention as claimed and as discussed above for claim 32, except for cooling a bulkhead of the combustor by directing the cooling air onto the bulkhead with the effusion holes of the second portion.
Cunha teaches (Fig. 6) a similar combustor (64) comprising a liner panel (128) having effusion holes (150), and further teaches:
cooling a bulkhead (74) of the combustor (64) by directing cooling air (152) onto the bulkhead (74) with the effusion holes (150).
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 Bronson, in view of Tu and Dudebout, by cooling a bulkhead of the combustor by directing the cooling air onto the bulkhead with the effusion holes of the second portion, in order to provide impingement cooling to the bulkhead, and thereby permit the temperature within an upstream portion of the combustion chamber to be increased to increase turbine engine efficiency and power without substantially increasing NOx, CO and unburned hydrocarbon (UHC) emissions of the turbine engine, as taught by Cunha (¶ [0067], ll. 4-6 and 10-15).
Claims 27-28 and 36 are rejected under 35 U.S.C. 103 as being unpatentable over Bronson (US 9,897,320 B2: IDS reference), in view of Tu (US 2016/0169515 A1) and Dudebout (US 2009/0084110 A1: IDS reference), and in further view of Kuhn (US 2008/0223835 A1: IDS reference) and Farmer (US 2004/0106360 A1: IDS reference).
Regarding claim 27, Bronson, in view of Tu and Dudebout, teaches the invention as claimed and as discussed above for claim 21, and Bronson further teaches (Figs. 3 and 5) the first plurality of effusion holes (304) are oriented through the liner panel (216) at a first angle (α1 – Fig. 5) relative to the inner surface (bottom surface of 216) and the second plurality of effusion holes (304) are oriented through the liner panel (216) at a second angle (α1) relative to the inner surface.
However, Bronson, in view of Tu and Dudebout, does not teach that the second angle is different than the first angle.
Kuhn teaches (Fig. 3) a similar combustor (100) comprising effusion holes (106), wherein “a first set of effusion holes may have a first shape and the channel 124 may be angled at an angle relative to the combustor second surface 104, while a second set of effusion holes may have the same shape or a different shape and the channel 124 may be angled at a different angle relative to the combustor second surface 104” (¶ [0026], ll. 16-21).
Farmer teaches (Fig. 3) a similar combustor (16 – Fig. 2) comprising effusion holes (88), and that “The oblique orientation of openings 88 facilitates film cooling of inner surfaces 90 and 92, such that a desired boundary layer thickness is maintained” (¶ [0020], ll. 3-5).
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 Bronson, in view of Tu and Dudebout, by having the second angle be different than the first angle, as taught by Kuhn, in order to maintain a desired boundary layer thickness (by adjusting each cooling hole individually to a desired oblique orientation or angle needed to maintain the boundary layer thickness desired), as taught by Farmer (¶ [0020], ll. 3-5).
Regarding claim 28, Bronson, in view of Tu, Dudebout, Kuhn, and Farmer, teaches the invention as claimed and as discussed above for claim 27, and Bronson further teaches (Fig. 5) the first angle (α1) is between 15 and 35 degrees (col. 5, ll. 44-45: “the inward angle (αI) is between about 10° and about 30°”). Note that the range of 10° – 30° overlaps the range of 15° – 35°.
Regarding claim 36, Bronson, in view of Tu and Dudebout, teaches the invention as claimed and as discussed above for claim 32, and Bronson further teaches (Figs. 3 and 5) the first plurality of effusion holes (304) are oriented through the liner panel (216) at a first angle (α1 – Fig. 5) relative to the inner surface (bottom surface of 216) and the second plurality of effusion holes (304) are oriented through the liner panel (216) at a second angle (α1) relative to the inner surface.
However, Bronson, in view of Tu and Dudebout, does not teach that the second angle is different than the first angle.
Kuhn teaches (Fig. 3) a similar combustor (100) comprising effusion holes (106), wherein “a first set of effusion holes may have a first shape and the channel 124 may be angled at an angle relative to the combustor second surface 104, while a second set of effusion holes may have the same shape or a different shape and the channel 124 may be angled at a different angle relative to the combustor second surface 104” (¶ [0026], ll. 16-21).
Farmer teaches (Fig. 3) a similar combustor (16 – Fig. 2) comprising effusion holes (88), and that “The oblique orientation of openings 88 facilitates film cooling of inner surfaces 90 and 92, such that a desired boundary layer thickness is maintained” (¶ [0020], ll. 3-5).
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 Bronson, in view of Tu and Dudebout, by having the second angle be different than the first angle, as taught by Kuhn, in order to maintain a desired boundary layer thickness (by adjusting each cooling hole individually to a desired oblique orientation or angle needed to maintain the boundary layer thickness desired), as taught by Farmer (¶ [0020], ll. 3-5).
Claims 37-40 are rejected under 35 U.S.C. 103 as being unpatentable over Bronson (US 9,897,320 B2: IDS reference), in view of Kuhn (US 2008/0223835 A1: IDS reference) and Farmer (US 2004/0106360 A1: IDS reference).
Regarding claim 37, Bronson teaches (Figs. 2, 3, and 5) a combustor (124 – Fig. 2) for a gas turbine engine (100 – Fig. 1), the combustor (124) comprising:
an inner shell (210 – Fig. 2) and an outer shell (218 – Fig. 2) extending circumferentially about an axis (coaxial with low pressure spool 138 – Fig. 1), the inner shell (210) and the outer shell (218) forming a combustion chamber (228 – Fig. 2) of the combustor (124) radially between the inner shell (210) and the outer shell (218);
a bulkhead (206 – Fig. 2) extending between the inner shell (210) and the outer shell (218); and
a liner panel (216) mounted on the inner shell (210) or the outer shell (218), the liner panel (216) extending radially between an inner surface (Fig. 2: bottom surface of 216) and an outer surface (Fig. 2: top surface of 216), the inner surface further forming the combustion chamber (228), the liner panel (216) extending axially (shown by axial line 314) between a forward end (224 – Fig. 3) and an aft end (226 – Fig. 3), the liner panel the liner panel (216) including a first section and a second section (see annotated Fig. 3 on page 25),
the first section including a first plurality of effusion holes (304) extending through the liner panel (216) from the inner surface to the outer surface, the first plurality of effusion holes (304) are oriented through the liner panel (216) at a first angle (α1 – Fig. 5) relative to the inner surface, the first plurality of effusion cooling holes (304) including a first portion, a second portion, and a third portion of the first plurality of effusion cooling holes (see annotated Fig. 3 on page 25),
effusion holes (304) of the first portion extending in a substantially circumferential direction (as shown in annotated Fig. 3 on page 25, effusion holes 304 in the first portion extend horizontally),
effusion holes (304) of the second portion disposed axially forward of the effusion holes (304) of the first portion, the effusion holes (304) of the second portion transitioning from the substantially circumferential direction toward a substantial forward direction as an axial distance from the effusion holes (304) of the first portion increases (as shown in annotated Fig. 3 on next page, effusion holes 304 in the second portion transition from extending horizontally to vertically when proceeding axially from the first portion to the second portion), and
effusion holes (304) of the third portion disposed axially aft of the effusion holes (304) of the first portion, the effusion holes (304) of the third portion transitioning from the substantially circumferential direction toward a substantial aft direction as an axial distance from the effusion holes (304) of the first portion increases (as shown in annotated Fig. 3 on next page, effusion holes 304 in the third portion transition from extending horizontally to vertically when proceeding axially from the first portion to the third portion), and
the second section disposed axially between the first section and the aft end (as shown in annotated Fig. 3 on next page), the second section including a second plurality of effusion holes (304) extending through the liner panel (216) from the inner surface to the outer surface, the second plurality of effusion holes (304) are oriented through the liner panel (216) at a second angle (α1) relative to the inner surface.
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However, Bronson does not teach the first section disposed at the forward end, and
effusion holes of the second portion disposed axially between the forward end and the effusion holes of the first portion.
As shown in annotated Fig. 3 of Bronson above, the second portion (which is part of the first section) does not extend to the forward end.
Bronson further teaches “the substantially transversely disposed effusion cooling holes 304 in each of the initial rows 306, 316 serve to establish a cooling film on the liner inner surfaces. The transition of the effusion cooling holes 304 from the substantially transverse tangential angle (αT) to the substantially axial tangential angle (αT) encourages cooling air flow in the downstream direction, which provides continued effective cooling of the liner inner surfaces while mitigating the swirl component of the upstream effusion cooling holes 304” (col. 5, l. 60 – col. 6, l. 2). Therefore, the tangential angle (αT), and thus the orientation, of the effusion cooling holes is a result-effective variable, i.e., a variable which achieves a recognized result. In re Antonie, 559 F.2d 618, 195 USPQ 6 (CCPA 1977); MPEP 2144.05(II)(B).
In this case, the recognized result is that the tangential angle (αT), and thus the orientation, of the effusion cooling holes can be varied in a design stage in order to provide one of two desired results: (1) a cooling film on the liner inner surface, or (2) continued effective cooling of the liner surfaces while mitigating the swirl component of the upstream effusion cooling holes.
Therefore, since the general conditions of the claim, i.e. that the tangential angle (αT), and thus the orientation, of the effusion cooling holes can be varied in a design stage in order to provide one of two desired results (as discussed above), were disclosed in the prior art by Bronson, it is not inventive to discover the optimum workable pattern of effusion holes in a specific orientation, and it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to vary the tangential angle (αT), and thus the orientation, of the effusion cooling holes in the region between the above annotated “Second portion” and the forward end to have a tangential angle of substantially 0° (i.e., within 5 degrees of 0°), thus extending in a substantial forward direction, as taught by Bronson, in order to provide continued effective cooling of the liner surfaces in this region (Bronson, col. 5, ll. 66-67), thereby allowing the pattern of effusion holes to accommodate, prevent or decrease thermal growth, stress and strain in a dual wall combustor (Bronson, col. 6, ll. 47-56). It has been held that “[W]here the general conditions of a claim are disclosed 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); MPEP 2144.05(II)(A).
Note that the above modification changes all effusion holes 304 in the region between the above annotated “Second portion” and forward end 224 to have the same orientation as the effusion holes of the “Second portion”, thereby extending the “Second portion” to forward end 224, and thus providing:
the first section disposed at the forward end, and
effusion holes of the second portion disposed axially between the forward end and the effusion holes of the first portion.
Additionally, Applicant has failed to provide evidence of criticality for having the effusion holes of the second portion disposed axially between the forward end and the effusion holes of the first portion, such that the effusion holes at the forward end are oriented in a substantially forward direction.
However, Bronson does not teach that the second angle is different than the first angle.
Kuhn teaches (Fig. 3) a similar combustor (100) comprising effusion holes (106), wherein “a first set of effusion holes may have a first shape and the channel 124 may be angled at an angle relative to the combustor second surface 104, while a second set of effusion holes may have the same shape or a different shape and the channel 124 may be angled at a different angle relative to the combustor second surface 104” (¶ [0026], ll. 16-21).
Farmer teaches (Fig. 3) a similar combustor (16 – Fig. 2) comprising effusion holes (88), and that “The oblique orientation of openings 88 facilitates film cooling of inner surfaces 90 and 92, such that a desired boundary layer thickness is maintained” (¶ [0020], ll. 3-5).
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 Bronson by having the second angle be different than the first angle, as taught by Kuhn, in order to maintain a desired boundary layer thickness (by adjusting each cooling hole individually to a desired oblique orientation or angle needed to maintain the boundary layer thickness desired), as taught by Farmer (¶ [0020], ll. 3-5).
Regarding claim 38, Bronson, in view of Kuhn and Farmer, teaches the invention as claimed and as discussed above for claim 37, and Bronson further teaches (Fig. 3) each of the second plurality of effusion holes (see annotated Fig. 3 on page 25) extends in the substantially aft direction from the outer surface to the inner surface (as shown in annotated Fig. 3, these holes extend in the vertical, or aft direction).
Regarding claim 39, Bronson, in view of Kuhn and Farmer, teaches the invention as claimed and as discussed above for claim 37, and Bronson further teaches (Fig. 3) the second section circumferentially interrupts the first section at the effusion holes (304) of the third portion (as shown in annotated Fig. 3 on page 25).
Regarding claim 40, Bronson, in view of Kuhn and Farmer, teaches the invention as claimed and as discussed above for claim 37, and Bronson further teaches (Fig. 5) the first angle (α1) is between 15 and 35 degrees (col. 5, ll. 44-45: “the inward angle (αI) is between about 10° and about 30°”). Note that the range of 10° – 30° overlaps the range of 15° – 35°.
Response to Arguments
Applicant's arguments filed March 2, 2026 have been fully considered but they are not persuasive.
Regarding Applicant’s argument (page 10, 1st para. of REMARKS) that “Under the Office Action’s segmentation of the alleged first portion and second portion, the effusion holes of the first portion are oriented circumferentially while the adjacent effusion holes of the second portion are simply axial; which is not the claimed ‘transition[] from the substantially circumferential direction toward a substantial forward direction as an axial distance from the effusion holes of the first portion increases”, Examiner maintains the position that effusion holes that are “simply axial” are also considered to be oriented in a forward direction. As shown in Fig. 3 of Bronson, the holes 304 in section 308 point in the vertical direction, which can be either the forward direction or the aft direction. Based on Applicant’s remarks, it is believed that Applicant is attempting to argue a narrower limitation that was not recited in the claims. For example, if the substantially forward direction was defined to be in the direction of the effusion holes from the outer surface to the inner surface of the liner panel, then the holes 304 in section 308 would not be oriented in a substantially forward direction.
Regarding Applicant’s argument (page 12, 2nd para.) that “This effusion hole configuration is not a parameter to be optimized. It is a structural arrangement of effusion holes across a defined region of the liner panel”, Examiner respectfully disagrees because any effusion hole located in any location of the liner panel may be optimized, and in this case, the tangential angle of the effusion holes near the forward end of the panel may be optimized to achieve a recognized result.
Regarding Applicant’s argument (page 12, Section B) that “The Office Action also does not cite any disclosure indicating that selecting a tangential angle of 0° for effusion holes in this region would achieve the asserted cooling benefit, nor does it provide any technical explanation linking the proposed modification to the alleged result. Instead, the Office Action states the generic, desired outcome–‘continued effective cooling’–without providing evidentiary support or reasoned analysis demonstrating that the specific modification would achieve that outcome”, the outcome statement of “continued effective cooling” is not generic. Rather, this statement comes directly from Bronson itself, see col. 5, l. 63 to col. 6, l. 2 of Bronson: “The transition of the effusion cooling holes 304 from the substantially transverse tangential angle (αT) to the substantially axial tangential angle (αT) encourages cooling air flow in the downstream direction, which provides continued effective cooling of the liner inner surfaces while mitigating the swirl component of the upstream effusion cooling holes 304”. Additionally, Bronson also provides in col. 6, ll. 5-9: “the repeated transition from a substantially transverse tangential angle (αT) to a substantially axial tangential angle (αT) maintains the cooling film downstream of these major combustor orifices, and helps increase overall combustor 124 cooling efficiency”. Therefore, it is evident from Bronson that the tangential angle affects the cooling aspect of the effusion holes such that transitioning from a substantially transverse angle to a substantially axial angle (i.e., near 0°) maintains cooling and increases overall combustor cooling efficiency.
Regarding Applicant’s argument (page 145, 4th para.) that “the Office Action does not explain how or why the alleged optimization of a parameter, such as the tangential angel (αT) of effusion holes, would result in repositioning the annotated first section of Bronson’s liner panel to the forward end”, as stated above, any effusion hole located in any location of the liner panel may be optimized, and in this case, the tangential angle of the effusion holes near the forward end are being optimized. The effusion holes are not being “repositioned” to the forward end of the liner.
It should be emphasized that Applicant has failed to provide evidence of criticality for having the effusion holes of the second portion disposed axially between the forward end and the effusion holes of the first portion, such that the effusion holes at the forward end are oriented in a substantially forward direction. There is nothing in Applicant’s specification that discusses why the effusion holes near the forward end of the liner should be oriented in a substantially forward direction, or how doing so achieves a specific result or effect.
Regarding Applicant’s argument (page 18, 2nd para.) that “The Office Action asserts that the modification would be made ‘in order to maintain a desired boundary layer thickness.’ This rationales is insufficient to support the conclusion of obviousness…The asserted rationale therefore explains, at most, why angled holes may be used, but does not explain why different sections of the liner should have different angles”, Kuhn explains in ¶ [0026], ll. 14-15 that “It will be appreciated that the effusion holes 106 may or may not all have substantially the same shape”. This includes having a first set of effusion holes being angled at a different angle from a second set of effusion holes, as stated in ¶ [0026], ll. 16-21. The angles of these effusion holes will obviously maintain film cooling, or a desired boundary layer thickness, as evidenced by Farmer. It should be noted that Kuhn also teaches in ¶ [0006], ll. 9-13: “To enhance effusion cooling, the area and shape of effusion holes may be varied from a smaller circular inlet to a larger, fan shaped outlet. Varying the area of the effusion holes may cause the air to diffuse so that its velocity is reduced as the air film forms.” Therefore, since the angle of an effusion hole is also part of its shape, varying the angle or shape will further enhance effusion cooling.
Examiner Note:
Applicant’s invention differs from Bronson’s invention in that Applicant’s effusion holes in the second portion transition from a substantially circumferential direction toward a substantially forward direction, from the outer surface to the inner surface of the liner panel, whereas Bronson’s effusion holes in the second portion transition from a substantially circumferential direction toward a substantially aft direction, from the outer surface to the inner surface of the liner panel. Claim limitations directed to the substantially forward direction as being from the outer surface to the inner surface of the liner panel may overcome the currently applied prior art in a future, potential office action.
Conclusion
THIS ACTION IS MADE FINAL. 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