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 .
Priority
Applicant’s claim for the benefit of a prior-filed application under 35 U.S.C. 119(e) or under 35 U.S.C. 120, 121, 365(c), or 386(c) is acknowledged.
Claim Rejections - 35 USC § 102
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
(a)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention.
Claim(s) 1, 3, 4, 9-14, 19 and 20 is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Koff et al. (US 5308225), hereinafter: “Koff”
In Regard to Claim 1
Koff teaches:
A method comprising:
providing a substrate(20) for a component(Fig 1-2) of a gas turbine engine(Col 3, ln. 23-25; Col 4, ln. 21-26), the substrate having a first surface(see annotated fig below) and a second surface(outermost radial surface of 20) opposite the first surface(see annotated fig below);
applying an abradable material(“rub strip”; Col 4, ln. 10-20) to the first surface of the substrate(see annotated fig below), the abradable material having a third surface(see annotated fig below) in contact with the first surface of the substrate to define an interface(see annotated fig below), the abradable material having a fourth surface opposite the third surface(see annotated fig below); and
fabricating a groove(26,34,36,56,58,60,62; Col 4, ln. 45-60 and Col 5, ln. 1-32) into the component such that the groove extends from the fourth surface of the abradable material to a fifth surface of the substrate(see annotated fig below), the fifth surface of the substrate disposed radially between the first and second surfaces of the substrate(see annotated fig below), the groove extending through the interface defined by the abradable material and the substrate(lateral walls of the groove extend from an open end radially through the interface and to a closed end within the substrate 20; see annotated fig below).
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In Regard to Claim 3
Koff teaches:
The method of claim 1(see rejection of claim 1 above), wherein the groove is fabricated at a region of the component positioned adjacent to a leading edge(32) of a blade(blade 18; as clearly shown in the annotated fig above, the groove is positioned in a region of the component adjacent leading edge 32 of blade 18).
In Regard to Claim 4
Koff teaches:
The method of claim 1(see rejection of claim 1 above), further including positioning the component adjacent to a tip of a blade(Fig 2; the component is positioned adjacent the tip portion of blade 18), the component positioned such that an opening of the groove faces the tip of the blade(an opening of the groove faces the tip portion of the blade; see annotated fig above).
In Regard to Claim 9
Koff teaches:
The method of claim 1(see rejection of claim 1 above), wherein the providing the substrate includes manufacturing the substrate, the substrate manufactured to have a first thickness defined between the first surface and the second surface(see annotated fig above).
In Regard to Claim 10
Koff teaches:
The method of claim 9(see rejection of claim 9 above), wherein the abradable material has a second thickness defined between the third surface and the fourth surface(see annotated fig above), and wherein the abradable material is applied such that the second thickness is smaller than the first thickness of the substrate(as shown in Fig 2, as annotated above, it is readily apparent that the second thickness is less the first thickness of the substrate).
In Regard to Claim 11
Koff teaches:
The method of claim 1(see rejection of claim 1 above), wherein the groove is a first groove, and further including fabricating a second groove into the component such that the second groove extends from the fourth surface of the abradable material to the fifth surface of the substrate, the second groove adjacent to the first groove(as shown in Fig 3-4, a second groove is adjacent the first groove also extending from the fourth surface of the abradable material to the fifth surface of the substrate).
In Regard to Claim 12
Koff teaches:
The method of claim 1(see rejection of claim 1 above), wherein the groove is fabricated axially along the component(as shown in Fig 2-4 the grooves extending axially along the component).
In Regard to Claim 13
Koff teaches:
The method of claim 1(see rejection of claim 1 above), wherein the groove is fabricated circumferentially around the component(60,62 extend circumferentially; Fig 4; Col 5, ln. 10-16).
In Regard to Claim 14
Koff teaches:
A method comprising:
fabricating a rotor casing(14) for gas turbine engine(Fig 1; Col 3, ln. 23-25; Col 4, ln. 21-26) by:
depositing an abradable material(“rub strip”; Col 4, ln. 10-20) onto a first surface(see annotated fig above) of a substrate(20), the substrate including the first surface and a second surface(outermost radial surface of 20) opposite the first surface(see annotated fig above); and
fabricating a recess(26,34,36,56,58,60,62; Col 4, ln. 45-60 and Col 5, ln. 1-32) into the abradable material and the substrate(see annotated fig above), the recess extending from third surface of the abradable material to a fourth surface of the substrate(see annotated fig above), the fourth surface of the substrate disposed radially between the first and second surfaces of the substrate(see annotated fig above); and
positioning the rotor casing adjacent to a tip of a rotor blade(Fig 2; the component is positioned adjacent the tip portion of blade 18) such that an opening of the recess faces the tip of the rotor blade(an opening of the recess faces the tip portion of the blade; see annotated fig above).
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In Regard to Claim 19
Koff teaches:
The method of claim 14(see rejection of claim 14 above), wherein the rotor casing has a first thickness(see annotated fig above) defined between the second surface of the substrate and the third surface of the abradable material(see annotated fig above); and
wherein the abradable material is deposited to have a second thickness defined between the third surface of the abradable material and a fifth surface of the abradable material(see annotated fig above), the fifth surface in contact with the first surface of the substrate, the second thickness smaller than the first thickness(as shown in Fig 2, as annotated above, it is readily apparent that the second thickness is less the first thickness of the substrate).
In Regard to Claim 20
Koff teaches:
The method of claim 19(see rejection of claim 19 above), wherein the rotor blade is configured to abrade the abradable material(the rotor blade abrades the “rub strip” during operation of the engine to form an outer air seal for the tips of the blades 18; Col 4, ln. 10-20), wherein the abradable material has a third thickness based on the abrasion of the abradable material(during operation the process of abrading the “rub strip” material from the rub strip is worn away at the point of contact between the rotor blade tip and the rub strip, as such, at the point of contact a third thickness is created based on the wearing away of the abradable material).
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claim(s) 2, 5, 6 and 8 is/are rejected under 35 U.S.C. 103 as being unpatentable over Koff in view of Shi et al. (US 20210188721), hereinafter: “Shi”.
In Regard to Claim 2
Koff teaches:
The method of claim 1(see rejection of claim 1 above), wherein the applying the abradable material includes:
depositing a first layer(“rub strip”; Col 4, ln. 10-20, see annotated fig above) of the abradable material onto the first surface of the substrate(see annotate fig above), the first layer extending from a first region(proximate the trailing edge of blade 18) of the first surface to a second region(proximate the leading edge of blade 18) of the first surface; and
Koff fails to teach:
depositing a second layer of the abradable material onto the first layer of the abradable material, the second layer deposited at the second region of the first surface of the substrate.
Shi teaches:
An analogous abradable coating system(Fig 2) wherein a first layer(120) of abradable material is deposited onto a first surface of a substrate(112,114,116), the first layer extending from a first region(proximate the trailing edge of rotating element 150) of the first surface to a second region(proximate the leading edge of rotating element 150) of the first surface; and
depositing a second layer(122) of the abradable material onto the first layer of the abradable material(Fig 2), the second layer deposited at the second region of the first surface of the substrate(proximate the leading edge of rotating element 150).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Koff to incorporate the teachings of Shi to deposit a second layer of the abradable material onto the first layer of abradable material at the second region in an effort to increase CMAS and water vapor resistance a varying blade cut depths(P[0005])
In Regard to Claim 5
Koff teaches:
The method of claim 1(see rejection of claim 1 above), wherein the applying the abradable material includes depositing the abradable material onto the first surface of the substrate(see annotated fig below).
Koff fails to teach:
wherein the applying the abradable material includes thermally spraying
Shi teaches:
An analogous abradable coating system(Fig 2) wherein the applying the abradable material includes thermally spraying the abradable material onto the substrate(P[0033], P[0055]).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Koff to incorporate the teachings of Shi to deposit the abradable material by thermally spraying the abradable material onto the substrate because using the known technique of thermal spraying of Shi to apply an abradable material to a substrate in a gas turbine engine would have been obvious to one of ordinary skill and would achieve predictable results. The predictable results in this case, is the application of an abradable material on a casing radially outside a rotor blade tip to protect the blades during rub events and maintain tight clearances between the rotor blade tips and the casing. See KSR; MPEP 2141 III C.
In Regard to Claim 6
Koff teaches:
The method of claim 1(see rejection of claim 1 above), wherein the applying the abradable material includes depositing the abradable material onto the first surface of the substrate(see annotated fig below).
Koff fails to teach:
wherein the applying the abradable material includes depositing the abradable material via electron beam physical vapor deposition (EBPVD).
Shi teaches:
An analogous abradable coating system(Fig 2) wherein applying the abradable material includes electron beam physical vapor deposition of the abradable material onto the substrate(P[0033], P[0055]).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Koff to incorporate the teachings of Shi to deposit the abradable material by electron beam physical vapor deposition onto the substrate because using the known technique of electron beam physical vapor deposition of Shi to apply an abradable material to a substrate in a gas turbine engine would have been obvious to one of ordinary skill and would achieve predictable results. The predictable results in this case, is the application of an abradable material on a casing radially outside a rotor blade tip to protect the blades during rub events and maintain tight clearances between the rotor blade tips and the casing. See KSR; MPEP 2141 III C.
In Regard to Claim 8
Koff teaches:
The method of claim 1(see rejection of claim 1 above), wherein the abradable material has a thickness defined between the third surface and the fourth surface
Koff fails to teach:
wherein the thickness is approximately between 30 milli-inches (mils) and 40 mils.
Shi teaches:
An analogous abradable coating system(Fig 2) wherein the total thickness of the abradable coating(18) is between 20 and 60 mils(P[0051]).
Additionally, Examiner notes that while Applicant’s specification mentions a preference of 30-40 mils thickness in P[0042], the specification fails to give criticality to the claimed range or provide evidence of any unexpected result within the claimed ranges. Applicant further states “the abradable material thickness 316 can be any thickness suitable to withstand abrasion during operation” in P[0042], which further evidences a lack of criticality of the claimed range. The thickness affects CMAS and thermal resistance(Shi; P[0045]) and the thickness need for a particular application may also be determined by the penetration or rub depth(Shi; P[0053]).
The Court has held that “where 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) (see MPEP §2144.05 II A for further clarification). In In re Aller, a claimed process which was performed at a temperature between 40°C and 80°C and an acid concentration between 25% and 70% was held to be obvious over a prior art process which differed from the claims only in that the reference process was performed at a temperature of 100°C and an acid concentration of 10%. Accordingly, it would have been prima facie obvious to one of ordinary skill in the art at the time the invention was made to have modified Koff in view of Shi to use set the thickness to be between 30 and 40 mils because such a modification would have been considered a mere design optimization which fails to patentably distinguish over the prior art.
Claim(s) 7 and 17 is/are rejected under 35 U.S.C. 103 as being unpatentable over Koff in view of Urac et al. (US 1010307), hereinafter: “Urac”.
In Regard to Claims 7 and 17
Koff teaches:
The method of claim 1(see rejection of claim 1 above) and The method of claim 14(see rejection of claim 14 above),
Koff fails to teach:
wherein the component is a casing for a compressor stage of the gas turbine engine;
and wherein the rotor blade is a compressor blade of a compressor of the gas turbine engine
Urac teaches:
An analogous method of applying an abradable coating(30) to a component(22) that is a casing for a compressor stage(14) of a gas turbine engine(10; Fig 2; Col 2, ln. 1-25) and wherein the casing surrounds a rotor blade(20) that is a compressor blade of the compressor of the gas turbine engine(Fig 2; Col 2, ln. 1-25).
Both Koff and Urac teach known methods for applying abradable coating in gas turbine engine components. Koff teaches a method for applying an abradable coating to a fan casing surrounding a fan blade, but does not teach applying the abradable coating to a compressor casing surrounding a compressor blade. Urac teaches a similar method for applying an abradable coating in a gas turbine engine. Urac specifically teaches that the method is applied to a compressor casing surrounding a compressor blade in a gas turbine engine or a fan of a gas turbine engine(Col 4, ln. 45-48) which provides a means for improving surge margin and reducing flow losses(Col 4, ln. 34-41). Thus, it would have been obvious to one or ordinary skill in the art before the effective filing date of the claimed invention, to apply the technique of applying the abradable coating as taught in Koff, to a compressor casing as taught in Urac. Using the known technique of applying an abradable coating to enhance surge/stall margin in the compressor section would have been obvious to one of ordinary skill. See KSR; MPEP 2141 III C.
Claim(s) 15 is/are rejected under 35 U.S.C. 103 as being unpatentable over Koff in view of Grande et al. (US 10494945), hereinafter: “Grande”.
In Regard to Claim 15
Koff teaches:
The method of claim 14(see rejection of claim 14 above) wherein the abradable material may be made of a suitable material(Col 4, Il. 15-18).
Koff fails to teach:
where the abradable material includes cobalt
Grande teaches:
An analogous abradable material that includes cobalt-nickel-chromium- aluminum- yttrium (CoNiCrAlY) and wherein the abradable material is a thermally sprayed to a first surface(Col 7, l. 34 to Col 8, l. 24).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Koff to incorporate the teachings of Grande to thermally spray cobalt-nickel-chromium-aluminum- yttrium (CoNiCrAlY) on the first surface since this is the application of a known material using a known technique to achieve predictable results. The predictable results in this case, is the application of an abradable material on a casing radially outside a rotor blade tip to protect the blades during rub events and maintain tight clearances between the rotor blade tips and the casing.
In further support of this position, the selection of a known material to make an abradable layer gas turbine casing liner prior to the invention was held to be obvious see In re Leshin, 277 F.2d 197, 125 USPQ 416 (CCPA 1960).
Claim(s) 16 is/are rejected under 35 U.S.C. 103 as being unpatentable over Koff in view of Official Notice.
In Regard to Claim 16
Koff teaches:
The method of claim 14(see rejection of claim 14 above)
Koff fails to teach:
wherein the recess is drilled into the abradable material and the substrate.
Official Notice is taken that drilling a recess into the abradable material and the substrate is old and well established in the business of gas turbine engines and is asserted to be a well-known expedient or common knowledge by those of skill in axial turbomachine art for their use removing material from the abradable material and the substrate to form the desired configuration of the recess for the application. Further, use of which is capable of instant and unquestionable demonstration as being well-known so as to defy dispute as demonstrated by the art of record. MPEP 2144. It would have been obvious to one skilled in the art before the effective filing date of the claimed invention to drill the recess into the abradable material and the substrate for the purposes of removing material from the abradable material and the substrate to form the desired configuration of the recess to suit the application. Furthermore, it would have been obvious to one having ordinary skill in the art to use the basic technique of drilling to form the recess, which yields no more than the predictable outcome which one of ordinary skill would have expected to achieve with this common tool of the trade, and is therefore an obvious engineering expedient.
Claim(s) 18 is/are rejected under 35 U.S.C. 103 as being unpatentable over Koff in view of Dynak et al. (US 11708770), hereinafter: “Dynak”.
In Regard to Claim 18
Koff teaches:
The method of claim 14(see rejection of claim 14 above) further including manufacturing the substrate from a metallic material(as indicated by the hatching of 14 in Fig 1-2)
Koff fails to teach:
wherein the substrate includes a ductile cast iron
Dyank teaches:
An analogous gas turbine engine having a casing made from a ductile cast iron material(Col 1, ln. 10-15).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Koff to incorporate the teachings of Dyank to construct the casing of a ductile cast iron material since Dyank teaches the use of a “ductile cast iron” is a known material suitable for making casings in turbine engines. It would have been obvious to one having ordinary skill in the art at the time of the invention to have selected a “ductile cast iron” because it is merely the selection of an art known material suitable for the construction of casing for a gas turbine engine. In further support of this position, the selection of a known material to make a casing prior to the invention was held to be obvious see In re Leshin, 277 F.2d 197, 125 USPQ 416 (CCPA 1960).
Conclusion
The following prior art made of record and not relied upon is considered pertinent to applicant's disclosure:
US 20180066527 A1
Kadau; Kai et al.
US 20180010469 A1
Kadau; Kai et al.
US 20080044273 A1
Khalid; Syed Arif
US 10247027 B2
Rioux; Philip R. et al.
US 4764089 A
Strangman; Thomas E.
US 11346367 B2
Yu; Hong et al.
US 11215070 B2
Urac; Tibor
US 3365172 A
HOWALD WERNER E et al.
The above reference are cited for teaching methods of fabricating a rotor casing and/or applying an abradable coating similar to the instant invention.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to BRIAN P WOLCOTT whose telephone number is (571)272-9837. The examiner can normally be reached M-F 8:00am-4:30pm.
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, Court D. Heinle can be reached at (571) 270-3508. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/BRIAN P WOLCOTT/Primary Examiner, Art Unit 3745