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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 10/02/2026 has been entered.
Response to Arguments
Applicant's arguments filed 09/02/2026 have been fully considered but they are not persuasive. Applicant primarily argues the there is no motivation of combine the references and the limitation regarding the graded transition layer being different from the teaching of Nissley now set forth in claim 1.
In response to applicant’s argument that there is no teaching, suggestion, or motivation to combine the references, the examiner recognizes that obviousness may be established by combining or modifying the teachings of the prior art to produce the claimed invention where there is some teaching, suggestion, or motivation to do so found either in the references themselves or in the knowledge generally available to one of ordinary skill in the art. See In re Fine, 837 F.2d 1071, 5 USPQ2d 1596 (Fed. Cir. 1988), In re Jones, 958 F.2d 347, 21 USPQ2d 1941 (Fed. Cir. 1992), and KSR International Co. v. Teleflex, Inc., 550 U.S. 398, 82 USPQ2d 1385 (2007). In this case, as set forth in the rejection, motivation is given for the combinations, and applicant has not why these motivations are not relevant for the coating of Guo. Further the references are within pertinent fields and use similar materials. Further, for example, alumina is known for use with MCrAlY bond coats regardless of the end use of the coating layer as proof Nissley teaches an alumina layer on the bond coat of the abradable coating.
Regarding Nissley, the limitation to the graded transition is a product by process limitation which is broadly claimed as no process parameters are claimed to decipher the intended structure. Thus, applicant arguments that a particular transition layer is claimed are not commensurate in scope with the claim language. It is noted for purposes of examination, product-by-process claims are not limited to the manipulation of the recited steps, only the structure implied by the steps. See MPEP 2113. In the present case, the recited steps imply a structure having a graded transition layer which at least in part comprises the composition of the abrasive layer. The modified reference set forth in the rejection suggests such a product.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(d):
(d) REFERENCE IN DEPENDENT FORMS.—Subject to subsection (e), a claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers.
The following is a quotation of pre-AIA 35 U.S.C. 112, fourth paragraph:
Subject to the following paragraph [i.e., the fifth paragraph of pre-AIA 35 U.S.C. 112], a claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers.
Claim 8 is rejected under 35 U.S.C. 112(d) or pre-AIA 35 U.S.C. 112, 4th paragraph, as being of improper dependent form for failing to further limit the subject matter of the claim upon which it depends, or for failing to include all the limitations of the claim upon which it depends. The limitation set forth in claim 7 limits the transition layer to 3 mils and thus claim 8 does not further limit the claim. Applicant may cancel the claim(s), amend the claim(s) to place the claim(s) in proper dependent form, rewrite the claim(s) in independent form, or present a sufficient showing that the dependent claim(s) complies with the statutory requirements.
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 8-10 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 Rajasekaran et al. (Enhanced Characteristics of HVOF-sprayed MCrAlY Bond Coats for TBC Applications), herein Rajasekaran, Nissley et al. (US 6102656), herein Nissley, Freling et al. US 20080219835 A1), herein Freling, Strock et al. (US 20120099985 A1), herein Strock.
In regards to claims 1 and 10, 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 teach the porosity or the oxygen content of the bond coat.
Rajasekaran teaches bond coats for TBC applications [Abstract, Title]. Rajasekaran teaches the bond coats have a porosity of less than 4% and oxygen content of less than 1 wt.% [Pgs. 1211, 1214]. The ranges are encompassed by the claimed ranges. Rajasekaran teaches that low porosity and oxygen content are desirable for TBC applications [Abstract, Pgs. 1214-1215].
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 bond coat with low oxygen content and porosity taught by Rajkasekaran as the bond coat of Gou. One would have been motivated to do so as it would have been the simple substitution of one known bond coat for another to achieve predictable results. Further, Rajasekaran teaches that low porosity and oxygen content of the bond coat is afford beneficial properties for TBC applications as such these properties would similarly enhance the seal of Gou.
Gou does not expressly teach an alumina interlayer is present in the seal disposed on the bond coat.
Nissley teaches an air seal seat which comprises a bond coat (14) disposed on a substrate (12), an alumina layer disposed on the bond coat, a graded interlayer (20), 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]. The alumina layer has a thickness of less than 5 mils [Col 7 lines 19-23].
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 Nissley to the seal layers of Gou. One would have been motivated to do so based on the added protection afforded by the layer. Additionally, as Nissley 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. Gou 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.
Guo fails to teach the seal further comprises a transition layer between the interlayer of alumina and the abrasive/abradable layer. The transition layer being a graded transition layer having a thickness of 3 mils. It is noted that the forming limitation is a product by process limitation.
Nissley teaches an abradable air seal seat which comprises a bond coat (14) disposed on a substrate (12), an alumina layer disposed on the bond coat, an interlayer 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) 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. The graded transition layer is to provide a strength link between the layers [Col 6 lines 38-47].
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.
It is noted for purposes of examination, product-by-process claims are not limited to the manipulation of the recited steps, only the structure implied by the steps. See MPEP 2113. In the present case, the recited steps imply a structure having a graded transition layer which at least in part comprises the composition of the abrasive layer. The modified reference suggests such a product.
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.
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, Nissley further teaches The alumina layer has a thickness of less than 5 mils [Col 7 lines 19-23]. 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 8, Nissley teaches the graded transition layer has a thickness of about 3 mils and about 10 mils [Col 6 lines 8-10].
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.
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.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ELIZABETH A COLLISTER whose telephone number is (571)270-1019. The examiner can normally be reached Mon.-Fri. 9 am-5 pm.
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/ELIZABETH COLLISTER/Primary Examiner, Art Unit 1784
