DETAILED ACTION
In view of the Appeal Brief filed on 09/03/2026, PROSECUTION IS HEREBY REOPENED. New grounds of rejection are set forth below.
To avoid abandonment of the application, appellant must exercise one of the following two options:
(1) file a reply under 37 CFR 1.111 (if this Office action is non-final) or a reply under 37 CFR 1.113 (if this Office action is final); or,
(2) initiate a new appeal by filing a notice of appeal under 37 CFR 41.31 followed by an appeal brief under 37 CFR 41.37. The previously paid notice of appeal fee and appeal brief fee can be applied to the new appeal. If, however, the appeal fees set forth in 37 CFR 41.20 have been increased since they were previously paid, then appellant must pay the difference between the increased fees and the amount previously paid.
A Supervisory Patent Examiner (SPE) has approved of reopening prosecution by signing below:
/DEVON C KRAMER/Supervisory Patent Examiner, Art Unit 3741
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 third office action on the merits. This office action is in response to the appeal brief filed on 09/03/2026. Since Examiner is applying new grounds of rejection to all the claims, this action supersedes the previous Final Office Action mailed on 03/26/2026. Claims 21-40 are currently pending and being examined.
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 (216) including a first section and a second section (see annotated Fig. 3 on page 6),
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 page 6),
effusion holes (304) of the first portion extending in a substantially circumferential direction (as shown in annotated Fig. 3 on page 6, 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 substantially 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 substantially 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.
PNG
media_image1.png
760
861
media_image1.png
Greyscale
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 146) including a first plurality of effusion holes (146) and a second section (Fig. 4A: comprising effusion holes 144) including a second plurality of effusion holes (144),
the first section (146) disposed at a forward end (140), and
the second section (144) disposed axially between the first section (146) 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 (146) – (as shown in Fig. 4A and as stated in ¶ [0049], ll. 2-4).
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 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 6) 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 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 6) 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 13) 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 13),
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 substantially 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 substantially 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).
PNG
media_image1.png
760
861
media_image1.png
Greyscale
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 146) including a first plurality of effusion holes (146) and a second section (Fig. 4A: comprising effusion holes 144) including a second plurality of effusion holes (144),
the first section (146) disposed at a forward end (140), and
the second section (144) disposed axially between the first section (146) 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 (146) – (as shown in Fig. 4A and as stated in ¶ [0049], ll. 2-4).
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 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 13) 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 13) 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).
PNG
media_image2.png
560
684
media_image2.png
Greyscale
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 (216) including a first section and a second section (see annotated Fig. 3 on page 24),
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 24),
effusion holes (304) of the first portion extending in a substantially circumferential direction (as shown in annotated Fig. 3 on page 24, 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 substantially 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 substantially 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.
PNG
media_image3.png
760
861
media_image3.png
Greyscale
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 24) 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 24).
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
The above new grounds of rejection is being made in response to Appellant's arguments on page 17, last two paragraphs, and pages 25-26 of the appeal brief. Only the 35 U.S.C. 103 rejections of independent claims 21, 32, and 37 are being amended. The 35 U.S.C. 103 rejections of dependent claims 22-31, 33-36, and 38-40 are maintained and unchanged.
On page 17, last two paragraphs, Appellant argued that Bronson does not teach that the annotated "second portion" (shown on page 14 of Final Office Action [FOA]) transitions from the substantially circumferential direction toward a substantially forward direction because "the holes closest to the first portion are already substantially axial, and the holes become increasing transverse as axial distance from the first portion increases". The new grounds of rejection addresses this argument by redrawing the second portion to include the bottom row of effusion holes from the first portion. Therefore, the new annotated “second portion” now transitions from the substantially circumferential direction (the top row shows horizontally-oriented effusion holes) toward a substantially forward direction (all other rows below the top row show vertically-oriented effusion holes).
On pages 25-26, Appellant argued that “Nothing in the cited Tu disclosure establishes that holes 144 have a greater density than holes 134” (last paragraph of page 26). The new grounds of rejection addresses this argument by amending the reference number for the first plurality of effusion holes in the first section. In the FOA, the 35 U.S.C. 103 rejection relied upon reference number “134” to teach the first plurality of effusion holes. For the new grounds of rejection, the reference number for the first plurality of effusion holes has been changed to “146”. Fig. 4A of Tu clearly shows that holes “144” have a greater density than holes “146”. This is also discussed in paragraph [0049] of Tu: “As shown, there is a greater number of cooling holes 144 at leading edge 142 than there are holes 146 adjacent the trailing edge 140”.
All other arguments made in the appeal brief have been fully considered but are not persuasive. These other arguments have been addressed in both the FOA filed March 26, 2026 and the Advisory Action filed June 4, 2026, and the response to these arguments are being maintained.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to HENRY NG whose telephone number is (571)272-2318. The examiner can normally be reached M-F 9:30 AM - 6:30 PM.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Devon Kramer can be reached at 571-272-7118. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/HENRY NG/Examiner, Art Unit 3741 /DEVON C KRAMER/Supervisory Patent Examiner, Art Unit 3741
Prosecution Insights