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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 10/6/2025 has been entered.
Claim Rejections - 35 USC § 103
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) 21, 23-29, 32, 33, 35, 38 is/are rejected under 35 U.S.C. 103 as being unpatentable over Liang (US 7665955 as referenced in OA dated 8/6/2025) in view of McCaffrey (US 20170350268 as referenced in OA dated 8/6/2025) and Bunker et al (US 20150345397)
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Annotated Figure 1 of Liang
Regarding claim 21, Liang discloses a shroud assembly (Figure 1; 10) for a turbine engine (Column 1, lines 12-15) having an engine centerline (Annotated Figure 1; labeled centerline. This is the centerline through the center of the gas turbine engine and extending longitudinally from the compressor to turbine) and a mainstream flow path (Annotated Figure 1; labeled mainstream flow path), the shroud assembly comprising:
a shroud (Figure 1; 16) comprising:
a body (The body of Figure 1; 16, 22) comprising a forward face (Annotated Figure 1; labeled forward face) and an aft face (Annotated Figure 1; labeled aft face), the body having a radially inner face (Figure 1; 20) and a radially outer face (Annotated Figure 1; labeled radially outer face), the radially inner face defining a respective portion of a circumferential perimeter (The respective portion of a circumferential perimeter of the mainstream flow path) of the mainstream flow path, the radially outer face defining a respective portion (The portion of Figure 1; 14 defined by the radially outer face) of a shroud cavity (Figure 1; 14);
a near wall cooling passage (Figure 1; 36, 34, 46, 18) extending through the body, the near wall cooling passage having an inlet channel (Figure 1; 36, 34, and the topmost portion of 46), an outlet channel (Figure 1; 44), and a connecting channel (The portions of Figure 1; 46 in the first and second layers) extending between the inlet channel and the outlet channel, the inlet channel having an inlet (The inlet of Figure 1; 36) provided along the radially outer face and being fluidly coupled to the shroud cavity, the outlet channel having an outlet (The outlet of Figure 1; 44) exhausting exterior the shroud cavity; and
a plurality of layers (Annotated Figure 1; labeled first, second, third layers) comprising:
a first layer (Annotated Figure 1; labeled first layer which includes the topmost part of 46) defining at least a portion (The portion of the radially outer face defined by the first layer) of the radially outer face and having a first aperture (The aperture defining the inlet channel) extending entirely through respective portions of the first layer, the first aperture defining a respective portion (The portion of the inlet channel defined by the first aperture) of the inlet channel; and
a second layer (Annotated Figure 1; labeled second layer) having a second aperture (The portion of Figure 1; 46 defined in the second layer) extending through an entirety of a respective portion (The entirety of a respective portion of the second layer through which Figure 1; 46 extends through) of the second layer, the second layer defining a first portion (The portion of Figure 1; 46 defined in the second layer) of the connecting channel, the portion of the first layer defining the first aperture stacked on a respective portion (The first layer extends along a respective portion of the second layer) of the second layer defining the second aperture, the first aperture opening to a respective portion (The first aperture opens to a respective portion of the second aperture)) of the second aperture; and
a third layer (Annotated Figure 1; labeled third layer) defining the radially inner face and a second portion (The portion of Figure 1; 46 defined in the third layer) of the connecting channel, the second layer extending along a respective portion (The second layer extends along a respective portion of the third layer) of the third layer and being provided between the first layer and the third layer, wherein the third layer is non-perforated from the forward face to the aft face at the radially inner face.
Liang does not disclose the shroud having a ceramic matrix composite (CMC) shroud segment, the inlet channel aligned at a non-parallel angle to a radial axis with respect to the engine centerline, and a plurality of CMC layers.
However, McCaffrey teaches a shroud (Figure 2; 74) having a ceramic matrix composite (CMC) shroud segment (Paragraph 0051) comprising:
a plurality of CMC layers (Figure 5; 140, 86).
Therefore, it would have been obvious to one of ordinary skill in the art at the time of effective filing to modify the invention of Liang wherein the shroud having a ceramic matrix composite (CMC) shroud segment and a plurality of CMC layers as taught by and suggested by McCaffrey in order to provide a shroud that is relatively strong, lightweight and temperature resistant (Paragraph 0068, The modification makes the shroud of Liang from CMC with plies stacked radially with respect to the engine centerline, so that the layers of Liang are CMC layers).
Liang in view of McCaffrey does not teach the inlet channel aligned at a non-parallel angle to a radial axis with respect to the engine centerline.
However, Bunker teaches an inlet channel (Figure 6; 52) aligned at a non-parallel angle (Figure 5 shows the inlet channel being aligned to a non-parallel angle to a radial axis with respect to the engine centerline) to a radial axis with respect to a engine centerline (The radial axis with respect to Figure 1; 26).
Therefore, it would have been obvious to one of ordinary skill in the art at the time of effective filing to modify the invention of Liang in view of McCaffrey wherein the inlet channel aligned at a non-parallel angle to a radial axis with respect to the engine centerline as taught by and suggested by Bunker in order to reduce particulate accumulation (Paragraph 0020, the modification has Figure 1; 36 of Liang being at a non-parallel angle to a radial axis with respect to the engine centerline).
Regarding claim 23, Liang in view of McCaffrey and Bunker teaches the invention as claimed.
Liang further discloses wherein the third layer (In the combined invention of Liang in view of McCaffrey, each layer of Liang is a CMC layer) has a third aperture (For claim 26-28, the portion of Figure 1; 46 through the third layer. Otherwise, the portion of Figure 1; 46 through the third layer and 18) extending partially through a portion (The portion of the third layer with the third aperture) of the third layer.
Regarding claim 24, Liang in view of McCaffrey and Bunker teaches the invention as claimed.
Liang further discloses wherein the second aperture opens to the third aperture.
Regarding claim 25, Liang in view of McCaffrey and Bunker teaches the invention as claimed.
Liang further discloses wherein the third aperture defines a respective portion of the outlet channel (The portion of the outlet channel defined by the third aperture).
Regarding claim 26, Liang in view of McCaffrey and Bunker teaches the invention as claimed.
Liang further discloses wherein the third aperture is included in a plurality of third apertures (Each portion of Figure 1; 46 through the third layer) spaced along the third layer (In the combined invention of Liang in view of McCaffrey, each layer of Liang is a CMC layer).
Regarding claim 27, Liang in view of McCaffrey and Bunker teaches the invention as claimed.
Liang further discloses wherein the third layer (In the combined invention of Liang in view of McCaffrey, each layer of Liang is a CMC layer) includes a third layer connecting aperture (The portion of Figure 1; 18 between and including the leftmost instance of 46 and the rightmost instance of 46) interconnecting at least two third apertures (The third apertures connected by the third layer connecting aperture) of the plurality of third apertures.
Regarding claim 28, Liang in view of McCaffrey and Bunker teaches the invention as claimed.
Liang further discloses wherein the third layer connecting aperture is included in a plurality of third layer connecting apertures (Figure 2 shows a plurality of 18) that extend between axially adjacent third apertures (Axially adjacent third apertures which are connected by the plurality of third layer connecting apertures) of the plurality of third apertures.
Regarding claim 29, Liang in view of McCaffrey and Bunker teaches the invention as claimed.
Liang further discloses wherein the third aperture has a larger cross-sectional area than the first aperture (The third aperture, in particular 18, has a larger cross-sectional area than the first aperture, in particular 36).
Regarding claim 32, Liang in view of McCaffrey and Bunker teaches the invention as claimed.
Liang further discloses wherein the second aperture is included in a plurality of second apertures (Each Figure 1; 46 in the second layer) spaced along the second layer (In the combined invention of Liang in view of McCaffrey, each layer of Liang is a CMC layer).
Regarding claim 33, Liang in view of McCaffrey and Bunker teaches the invention as claimed.
Liang further discloses wherein the first aperture is included in a plurality of first apertures (Each inlet of Figure 1; 46 in the first layer) spaced along the first layer (In the combined invention of Liang in view of McCaffrey, each layer of Liang is a CMC layer), and wherein the first layer includes a first layer connecting aperture (Figure 1; 34) interconnecting at least two first apertures (Any two Figure 1; 36 connected by 34) of the plurality of first apertures.
Regarding claim 35, Liang in view of McCaffrey and Bunker teaches the invention as claimed.
Liang further discloses wherein the first layer (In the combined invention of Liang in view of McCaffrey, each layer of Liang is a CMC layer) is radially stacked on the second layer.
Regarding claim 38, Liang in view of McCaffrey and Bunker teaches the invention as claimed.
Liang further discloses a rail (Annotated Figure 1; labeled rail) extending radially outward from the radially outer face, with the inlet channel being provided on a first axial side (The left side of Annotated Figure 1; labeled rail) of the rail, and the outlet channel being provided on a second axial side (The right side of Annotated Figure 1; labeled rail) of the rail, opposite the first axial side.
Claim(s) 34 is/are rejected under 35 U.S.C. 103 as being unpatentable over Liang in view of McCaffrey and Bunker as applied to claim 33 above, and further in view of Pietraszkiewicz et al (US 20090067994)
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Annotated Figure 3 of Pietraszkiewicz
Regarding claim 34, Liang in view of McCaffrey and Bunker teaches the invention as claimed.
Liang in view of McCaffrey does not teach wherein the first layer connecting aperture is included in a plurality of first layer connecting apertures extending both axially and circumferentially along the first CMC layer.
However, Pietraszkiewicz teaches wherein a first layer connecting aperture (Figure 3; 90) is included in a plurality of first layer connecting apertures (Figure 3; 90, 92) extending both axially and circumferentially (Each first layer connecting aperture extends axially and circumferentially with respect to Figure 2; 500) along a first layer (In the combined invention of Liang in view of McCaffrey, each layer of Pietraszkiewicz is a CMC layer).
Therefore, it would have been obvious to one of ordinary skill in the art at the time of effective filing to modify the invention of Liang in view of McCaffrey and Bunker wherein the first layer connecting aperture is included in a plurality of first layer connecting apertures extending both axially and circumferentially along the first CMC layer as taught by and suggested by Pietraszkiewicz in order to define fore and aft chambers/cavities (Paragraph 0016, the modification adds a rib to Figure 1; 34 of Liang).
Response to Arguments
Applicant’s arguments with respect to claim(s) 21 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
Applicant's arguments filed 10/6/2025 have been fully considered but they are not persuasive. Applicant asserts that Liang does not disclose the portion of the first CMC layer defining the first aperture stacked on a respective portion of the second CMC layer defining the second aperture. Examiner respectfully disagrees. In Liang, the first aperture includes the topmost portion of Figure 1; 46, so that the portion of the first CMC layer defining the first aperture is stacked on a respective portion of the second CMC layer defining the second aperture.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Evain et al (US 20170226861 as referenced in OA dated 4/2/2025) states in Paragraph 0079 that an abradable component can be made of CMC
Any inquiry concerning this communication or earlier communications from the examiner should be directed to EDWIN G KANG whose telephone number is (571)272-9814. The examiner can normally be reached Mon-Fri 8:00-5:00 PM EST.
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/EDWIN KANG/Primary Examiner, Art Unit 3741