DETAILED 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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 01/06/2026 has been entered.
Response to Arguments
Applicant’s arguments, see Pgs. 1-7, filed 12/03/2025, with respect to the rejections of claims under Nissley and separately on Strock have been fully considered and are persuasive. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground(s) of rejection is made in view of Gou et al. (US 20120099972 A1) [IDs dated 12/05/2023], herein Guo in view of Yasuda et al. (US 6071627 A) [IDS dated 12/05/2023], herein Yasuda, Freling et al. US 20080219835 A1), herein Freling and Strock et al. (US 20120099985 A1), herein Strock.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claims 1, 3-6 and 9 are rejected under 35 U.S.C. 103 as being unpatentable over Gou et al. (US 20120099972 A1) [IDs dated 12/05/2023], herein Guo in view of Yasuda et al. (US 6071627 A) [IDS dated 12/05/2023], herein Yasuda, Freling et al. US 20080219835 A1), herein Freling and Strock et al. (US 20120099985 A1), herein Strock.
In regards to claim 1, Gou teaches abradable/abrasive air seals for compressor rotors of gas turbine engines [Abstract, 0002-0004, 0012, 0021]. The seal applied to the part surface comprises a bond coat on the surface of the part and a ceramic coating further deposited on the bond coat [Abstract, 0023].
Gou does not expressly teach an alumina interlayer is present in the seal disposed on the bond coat.
Yasuda teaches heat resistant ceramic coating for jet engines or gas turbines [Abstract, claims 1-2, col 1 lines 12-18]. Between the bonding layer (12) and the ceramic top coat (13), Yasuda teaches an intermediate coating (14) of alumina is present [Col 11 lines 64-67, Col 12 lines 17-23, Fig. 9].
Yasuda teaches alumina is chosen for its high melting point and its stability when it is kept in a high temperature for a long time [Col 12 lines 1-6, 17-23, Col 21, Table 4]. Yasuda further teaches the thickness of the interlayer is 20-100 microns (0.79-3.94 mils) and by example 30 microns (1.18 mils) [Col 13, lines 35-40, Col 21, lines 25-30 (example 20)]. This range is encompassed in the claimed range.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to have added the alumina interlay in the thickness range taught by Yasuda to the seal layers of Gou. One would have been motivated to do so based on the high melting point and the layers stability when it is kept in a high temperature for a long time. Additionally, as Yasuda teaches this is a conventionally known coating interlayer material between a bond coating a ceramic layer one would have had reasonable expectation of success.
Gou does not teach the hardness on the Mohs scale of the abrasive layer. Geo teaches the abrasive/abradable layer comprises zirconia [0026-0027].
Strock teaches seal members with an abrasive layer for gas turbine engine components including the compressor [Abstract, 0002]. The abrasive layer is a ceramic abrasive layer has a hardness of at least 7 on the Mohs scale of mineral hardness [claim 6, 0007, 0031]. Strock teaches the abrasive layer comprises zirconia [0031].
It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to have ensured the ceramic of the abrasive layer of modified Guo has a hardness in the range taught by Strock. One would have been motivated to do so as Strock teaches this is a conventionally known range for an abradable seal and thus one would have had a reasonable expectation of success.
Gou does not expressly teach that the substrate/part is a rotor land of the compressor.
Freling teaches air seals for gas turbine engine components [Abstract]. Freling further teaches the inner air abradable seals are provided on rotor lands in the compressor sections [004-005, 0016, Figs. 2-3, claim 15].
It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to have used the abradable air seal of modified Guo on a compressor rotor land as taught by Freling. One would have been motivated to do so as it would have been the simple substitution of one abradable air seal for compressors for another and thus one would have had a reasonable expectation of success.
As set forth in MPEP 2144.05, in the case where the claimed range “overlap or lie inside ranges disclosed by the prior art”, a prima facie case of obviousness exists, In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990).
In regards to claim 3, Gou further teaches the bond coat comprises MCrAlY and has a thickness of about 3 mils to about 7 mils [0024-0025]. This overlaps the claimed range.
As set forth in MPEP 2144.05, in the case where the claimed range “overlap or lie inside ranges disclosed by the prior art”, a prima facie case of obviousness exists, In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990).
In regards to claim 4, Yasuda further teaches the thickness of the interlayer is 20-100 microns (0.79-3.94 mils) and by example 30 microns (1.18 mils) [Col 13, lines 35-40, Col 21, lines 25-30 (example 20)]. This range overlaps the claimed range.
In regards to claim 5, Gou further teaches the abradable layer has a thickness of preferably 19 to 21 mils [0029]. This range overlaps the claimed range.
In regards to claim 6, Gou further teaches the abradable layer has a surface roughness of 100 to 300 microinches [0031]. This overlaps the claimed range.
In regards to claim 9, Freling further teaches that the abradable seals are provided to rotor lands that extend between disk rims of adjacent disks, each disk supporting a compressor blade and rotating about a centerline axis of the compressor to rotate the compressor blade [0016-0017].
It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to have used the abradable air seal of modified Guo on a compressor rotor land as taught by Freling. One would have been motivated to do so as it would have been the simple substitution of one abradable air seal for compressors for another and thus one would have had a reasonable expectation of success.
Claims 7-8 are rejected under 35 U.S.C. 103 as being unpatentable over Gou et al. (US 20120099972 A1) [IDs dated 12/05/2023], herein Guo in view of Yasuda et al. (US 6071627 A) [IDS dated 12/05/2023], herein Yasuda, Freling et al. US 20080219835 A1), herein Freling and Strock et al. (US 20120099985 A1), herein Strock, as applied to claim 1 above, and further in view of Nissley et al. (US 5780171 A1), herein Nissley.
In regards to claims 7-8, modified Guo fails to teach the seal further comprises a transition layer between the interlayer of alumina and the abrasive/abradable layer.
Nissley teaches an inner air seal seat which comprises a bond coat (14) disposed on a substrate (12), an interlayer (18) disposed on the bond coat and an abrasive top coat layer (22) is disposed on the interlayer [Abstract, Col 1 lines 29-28, Col 2 lines 5-15, Col 5 lines 5-11, Col 6 lines 13-35, Col 7 lines 24-27, Figs. 1-2]. Nissley further teaches the interlayer has a graded transition layer (20) deposited on [Col 7 lines 30-33].
Nissley expressly teaches the transition layer is a compositional blend of the abradable top layer and the interlayer/foundation layer, i.e., a blend of the two layers it is in between [Col 2 lines 5-19, Col 6 lines 13-43]. The graded transition layer has a thickness of about 3 mils to about 10 mils [Claim 1]. This range includes the claimed value.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to have provided a graded transition layer as taught by Nissley to the seal layers of modified Guo. One would have been motivated to do so as it would have been the use of a known technique to improve the seal in the same way, for example improving the adhesion of the layers and minimizing the abrupt local changes in properties and thus stresses between the layers.
Modified Guo differs from the claim by failing to disclose an anticipatory examples or ranges that are sufficiently specific to anticipate the claimed ranges.
However, it has been held that overlapping ranges are sufficient to establish prima facie obviousness.
Therefore, it would have been obvious to one of ordinary skill in the art at the time of the invention to have selected from the overlapping portion of the range taught by the reference, because overlapping ranges have been held to establish prima facie obviousness. See MPEP 2144.05.
Conclusion
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/ELIZABETH COLLISTER/Primary Examiner, Art Unit 1784