United Technologies Corporation

Patent Trials and Appeals Board

Jul 27, 2021

2021000756 (P.T.A.B. Jul. 27, 2021)

UNITED STATES PATENT AND TRADEMARK OFFICE
UNITED STATES DEPARTMENT OF COMMERCE
United States Patent and Trademark Office
Address: COMMISSIONER FOR PATENTS
P.O. Box 1450
Alexandria, Virginia 22313-1450
www.uspto.gov
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO.
16/207,918 12/03/2018 William M. Barker 67097-3899PUS1;104846US01 7387
54549 7590 07/27/2021
CARLSON, GASKEY & OLDS/PRATT & WHITNEY
400 West Maple Road
Suite 350
Birmingham, MI 48009
EXAMINER
REITZ, MICHAEL K.
ART UNIT PAPER NUMBER
3745
NOTIFICATION DATE DELIVERY MODE
07/27/2021 ELECTRONIC
Please find below and/or attached an Office communication concerning this application or proceeding.
The time period for reply, if any, is set in the attached communication.
Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the
following e-mail address(es):
ptodocket@cgolaw.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte WILLIAM M. BARKER and THOMAS E. CLARK
Appeal 2021-000756
Application 16/207,918
Technology Center 3700
Before JILL D. HILL, CARL M. DEFRANCO, and LEE L. STEPINA,
Administrative Patent Judges.
STEPINA, Administrative Patent Judge.
DECISION ON APPEAL
STATEMENT OF THE CASE
Pursuant to 35 U.S.C. § 134(a), Appellant1 appeals from the
Examiner’s decision to reject claims 1–3, 6–16, and 18–22. We have
jurisdiction under 35 U.S.C. § 6(b).
We AFFIRM IN PART.

1 We use the word Appellant to refer to “applicant” as defined in 37 C.F.R.
§ 1.42(a). Appellant identifies the real party in interest as Raytheon
Technologies Corporation. Appeal Br. 1.
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Application 16/207,918

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CLAIMED SUBJECT MATTER
Appellant’s invention relates to a blade outer air seal having a ceramic
matrix composite. Claims 1 and 15 are independent. Claim 1, reproduced
below, is illustrative of the claimed subject matter:
1. A method of forming a blade outer air seal, comprising:
applying a cavity layer having a plurality of cavities to a
radially inner side of a seal body, wherein the cavity layer is
formed as a continuous sheet having the plurality of cavities and
cut to size before being applied to the seal body, wherein the seal
body and the cavity layer are a ceramic matrix composite
material; and
coating the cavity layer with an abradable coating.
REFERENCES
The prior art relied upon by the Examiner is:
Name Reference Date
Le Biez US 6,830,428 B2 Dec. 14, 2004
Strock ’774 US 2016/0032774 A1 Feb. 4, 2016
Strock ’551 US 2016/0040551 A1 Feb. 11, 2016
Landwehr US 2019/0292931 A1 Sept. 26, 2019
REJECTIONS
I. Claims 1–3, 6, 7, 9–14, and 21 are rejected under 35 U.S.C.
§ 103 as unpatentable over Strock ’551, Landwehr and Strock ’774.
II. Claim 8 is rejected under 35 U.S.C. § 103 as unpatentable over
Strock ’551, Landwehr, Strock ’774, and Le Biez.
III. Claims 15, 16 and 182 are rejected under 35 U.S.C. § 103 as
unpatentable over Strock ’551 and Le Biez.

2 We understand the Examiner’s inclusion of claims 17 and 20 in the
heading of Rejection III to be a typographical error inasmuch as claim 17 is
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IV. Claims 19, 20, and 22 are rejected under 35 U.S.C. § 103 as
unpatentable over Strock ’551, Le Biez, and Landwehr.
OPINION
Rejection I; Obviousness based on Strock ’551, Landwehr, and Strock ’774
Claims 1–3, 6, 7, 9–14
Appellant makes arguments for the patentability of claims 1–3, 6, 7,
and 9–14 as a group. Appeal Br. 3–4. We select claim 1 as the
representative claim, and claims 2, 3, 6, 7, and 9–14 stand or fall with
claim 1. 37 C.F.R. § 41.37(c)(1)(iv).
The Examiner finds that Strock ’551 discloses a blade outer air seal
having a seal body, a cavity layer and an abradable coating, but does not
disclose the materials for the seal body and cavity layer, or the steps for
manufacturing the layers. Final Act. 4. However, the Examiner finds,
“Strock also teaches that the material of the substrate that acts as the seal
body is not limited to any particular kind ([0039]).” Id. The Examiner also
finds that Landwehr teaches a seal body and cavity layer that are a ceramic
matrix composite material and considers that one of ordinary skill in the art
would have used ceramic matrix composite materials for the components of
Strock ’551 to get the thermal and mechanical properties taught by
Landwehr. Id. (citing Landwehr ¶ 2). The Examiner further finds that
Strock ’774 teaches a method of manufacturing a blade outer air seal and
considers that it would have been obvious to have manufactured the

canceled, and the body of Rejection III does not discuss claim 20, and,
rather, claim 20 is discussed in Rejection IV. See Final Act. 6.
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components of Strock ’551 as taught by Strock ’774 as a known economical
manufacturing process. Id.
Appellant asserts that Strock ’551 discloses forming surface features
by end mill or etching processes, but does not suggest applying a cavity
layer having cavities to a seal body. Appeal Br. 3; see also Reply Br. 2.
Appellant argues that “[n]one of the references disclose” this limitation. Id.
Appellant’s argument does not apprise us of Examiner error. The
Examiner finds that Strock ’551 discloses a substrate 50 and a cavity layer,
namely, surface layer 54 having surface geometry (cavities) 52 formed on
substrate 50. Final Act. 4; see also Strock ’551 ¶ 34, Fig. 3. The Examiner
also finds that Strock ’551 teaches the cavity layer is formed as a continuous
sheet, but is “silent regarding the exact manufacturing steps,” and that Strock
’774 teaches the manufacturing step of cutting a sheet to size before
applying the sheet to a substrate. Id.; see also Strock ’551 ¶ 36; Strock ’774
¶¶ 43, 44. Given that both Strock ’551 and Strock ’774 have a cavity layer
formed as a sheet and the Examiner relies on Strock ’774’s manufacturing
steps, a preponderance of the evidence supports the Examiner’s finding that
the combined teachings of the references teach a cavity layer having a
plurality of cavities is formed as a sheet and applied to the substrate.
Appellant also argues that because the sheet of Strock ’774 is metal or
MAXMET, there is no suggestion that the teachings of Strock ’774 would
apply to a ceramic matrix composite sheet. Appeal Br. 3.
The Examiner responds that Strock ’774 teaches, generally, forming a
separate cavity layer (preform sheet), cutting it to size, and applying it to a
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substrate. Ans. 3. According to the Examiner, Strock ’774’s teaching is
applicable regardless of the material choice.3 Id. at 4.
The Examiner has the better position. Strock ’774 discloses that
preforming a sheet is economical because it can be mass produced and cut to
size for use in various gas turbine parts. Strock ’774 ¶ 44. We agree with
the Examiner that the materials of Strock ’774 are not limited to metals.
That is, Strock ’774 does not require metals and teaches that “preformed
sheet 54 may comprise a metallic or MAXMET sheet of material.” Strock
’774 ¶ 35. Thus, we are not apprised of Examiner error.
For these reasons, we affirm the Examiner's rejection of claim 1 as
unpatentable over Strock ’551, Landwehr, and Strock ’774. Claims 2, 3, 6,
7, and 9–14 fall with claim 1.
Claim 21
Claim 21 depends from claim 1 and requires that the continuous sheet
is a 3D woven honeycomb sheet. Appeal Br. 8 (Claims App.).
The Examiner finds that the continuous sheet of Strock ’551 would be
a 3D woven honeycomb sheet based on Landwehr’s disclosure of a 3D
woven sheet. Final Act. 6 (citing Landwehr ¶ 17).
Appellant asserts that although Landwehr discloses a 3D woven
ceramic layer, there is no modification of the 3D woven layer to have
hexagonal cavities, and no suggestion that such a modification would be
possible. Appeal Br. 4; see also Reply Br. 2.

3 Appellant does not assert that the combination proposed by the Examiner
would have been beyond the abilities of one of ordinary skill in the art or
would have yielded unpredictable results.
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The Examiner responds that the rationale applied in this rejection is
the same as that applied in the rejection of claim 1, namely, to take
advantage of the thermal and mechanical properties of ceramic matrix
composite materials. Ans. 4. According to the Examiner, using the 3D
woven construction of Landwehr in “the cavity layer of Strock results in the
continuous sheet is a 3D woven honeycomb sheet.” Id. at 4–5.
For the following reason, we do not sustain the rejection of claim 21.
The Examiner’s position appears to be that using a 3D woven construction
for a cavity layer having hexagonal cavities necessarily results in a 3D
woven honeycomb structure. Appellant’s Specification, however,
distinguishes between a woven honeycomb sheet and a woven sheet that has
cavities drilled therein. Spec. ¶ 52. In particular, the Specification discloses
that “sheet 131 may be 3D woven with the honeycomb structure, and may be
adapted for chemical vapor infiltration. In other embodiments, the sheet 131
may be woven as a solid CMC sheet, with cavities 134 drilled in.” Id.
Given that Strock ’551 discloses forming surface feature (cavities) using end
mill or etching processes and Landwehr is silent as to cavities in the 3D
woven ceramic layer, the combined teachings of the references is more akin
to Appellant’s embodiment of a solid CMC sheet with cavities drilled
(milled, etched) in. We agree with Appellant that the Examiner has not
established adequately that the combined teachings of Strock ’551 and
Landwehr results in 3D woven honeycomb structure. See Appeal Br. 4.
Rejection II; Obviousness – Claim 8
Rejection II is based on the combination of Strock ’551, Landwehr,
and Strock ’774, with the addition of Le Biez. Final Act. 6.
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Appellant asserts that Le Biez does not cure the deficiencies of the
rejection of claim 1. Appeal Br. 4. For the reasons set forth above,
however, we are not apprised of any deficiency in the rejection of claim 1.
Accordingly, we sustain the rejection of claim 8 as unpatentable over
Strock ’551, Landwehr, Strock ’774, and Le Biez.

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Rejection III; Obviousness based on Strock ’551 and Le Biez
The Examiner finds that Strock ’551 discloses a blade outer air seal
having a cavity layer and an abradable coating over the cavity layer, but that
the cavity layer does not have the claimed solidity. Final Act. 6. The
Examiner finds that Le Biez teaches a cavity layer having solidity between
about 20% and 80%. Id. (citing Le Biez, 4:35–42). The Examiner
concludes that it would have been obvious to use the solidity of Le Biez in
the cavity layer of Strock ’551 “for its abradability while having adequate
mechanical strength.” Id. at 7 (citing Le Biez, 2:8–14).
Appellant asserts that the Examiner’s rejection is not supported
because the cavities in Le Biez are in an abradable layer, not a cavity layer
that is covered by an abradable layer. Appeal Br. 4–5. According to
Appellant, there is no rational reason to modify the cavity layer of Strock
’551 as suggested by the Examiner because Strock ’551’s cavity layer is not
abraded. Id. at 5.
The Examiner responds that Appellant does not provide evidence that
the cavity layer of Strock ’551 is not abraded. Ans. 5. According to the
Examiner, the teaching of Le Biez with respect to an abradable layer with
cavities is “applicable to the highly analogous cavity layer of Strock, and the
rationale provided in the rejection of a porosity of 40%–60% being chosen is
valid.” Id.
Appellant has the better position. Strock ’551 discloses that seal
member 30 includes a substrate 50, plural surface geometry features 52
formed in surface 54, and “a thermally insulating topcoat 56 ( e.g., a thermal
barrier or TBC) disposed over the plurality of features 52 formed in the
surface 54.” Strock ’551 ¶ 34. Strock ’551 further discloses that “thermally
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insulating topcoat 56 may be an abradable coating” having various
porosities. Id. ¶ 41. Strock ’551 also discloses that turbine blade outer air
seals conventionally include an abradable ceramic coating that contacts tips
of the turbine blades such that the blades abrade the coating upon operation
of the engine, but that the coating can develop internal stresses that may lead
to erosion and spalling. Id. ¶ 4. Le Biez discloses that providing cavities in
the abradable coating increases considerably the abradability of the coating,
without harming the mechanical strength of the coating. Le Biez, 2:8–14.
Although we appreciate that the blades of Strock ’551 may contact the
cavity layer in an extreme event (Ans. 5), given that Strock ’551 and Le Biez
both use an abradable coating to maximize efficiency by having the
abradable coating in contact with the blades (Strock ’551 ¶¶ 4, 42; Le Biez,
1:29–43), the Examiner does not explain adequately why the porosity of the
abradable layer in Le Biez is applicable to the cavity layer of Strock ’551.
Strock ’551’s disclosure that typical porosities in the abradable layer “in a
seal application include 5 to 70% by volume” (Strock ’551 ¶ 41) might lead
one of ordinary skill in the art to use Le Biez’s more specific range of 40 to
60% for the abradable layer, but does not suggest using this same range for
the cavity layer.
For these reasons, we do not sustain the Examiner’s rejection of claim
15, and claims 16 and 18 depending therefrom.
Rejection IV; Obviousness based on Strock ’551, Le Biez and Landwehr
Claims 19, 20, and 22 depend from claim 15. Spec. 8 (Claims App.).
The Examiner does not rely on the teachings of Landwehr in any manner
that would remedy the deficiencies discussed above regarding the rejection
based on Strock ’551 and Le Biez. See Final Act. 7–8. Accordingly, we do
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not sustain the rejection of claims 19, 20, and 22 as unpatentable over Strock
’551, Le Biez and Landwehr.
CONCLUSION
The Examiner’s rejections are affirmed in part.
DECISION SUMMARY
In summary:
Claim(s)
Rejected
35 U.S.C. § Reference(s)/Basis Affirmed Reversed
1–3, 6, 7, 9–
14, 21
103 Strock ’551,
Landwehr, Strock
’774
1–3, 6, 7, 9–
14
21
8 103 Strock ’551,
Landwehr, Strock
’774
8
15, 16, 18 103 Strock ’551, Le Biez 15, 16, 18
19, 20, 22 103 Strock ’551, Le
Biez, Landwehr
19, 20, 22
Overall
Outcome
1–3, 6–14 15, 16,
18–22
TIME PERIOD FOR RESPONSE
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a). See 37 C.F.R.
§ 1.136(a)(1)(iv).
AFFIRMED IN PART