Ex Parte Guo et al

Patent Trial and Appeal Board

Jul 24, 2017

13095947 (P.T.A.B. Jul. 24, 2017)

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.
13/095,947 04/28/2011 Changsheng Guo PA15621U;67097-2305PUS1 3575
54549 7590 07/26/2017
CARLSON, GASKEY & OLDS/PRATT & WHITNEY
400 West Maple Road
Suite 350
Birmingham, MI 48009
EXAMINER
PETERS, BRIAN O
ART UNIT PAPER NUMBER
3745
NOTIFICATION DATE DELIVERY MODE
07/26/2017 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 CHANGSHENG GUO and
TANIA BHATIA KASHYAP
Appeal 2016-000432
Application 13/095,947
Technology Center 3700
Before LINDA E. HORNER, LYNNE H. BROWNE, and
PAUL J. KORNICZKY, Administrative Patent Judges.
BROWNE, Administrative Patent Judge.
DECISION ON APPEAL
STATEMENT OF THE CASE
Changsheng Guo and Tania Bhatia Kashyap (Appellants) appeal
under 35 U.S.C. § 134 from the rejection of claims 1—4, 8—15, 17, 18, 20,
23—28, and 32—34 under 35 U.S.C. § 103(a) as unpatentable over Habarou
(US 8,496,431 B2, iss. July 30, 2013), Forrester (US 6,113,347, iss. Sept. 5,
2000), and Jackson (4,884,820, iss. Dec. 5, 1989). We have jurisdiction
under 35 U.S.C. § 6(b).1
1 The rejection of claims 3, 4, 17, and 18 under 35 U.S.C. § 112, second
paragraph was withdrawn in the Advisory Action dated February 10, 2015.
Appeal 2016-000432
Application 13/095,947
We reverse.
CLAIMED SUBJECT MATTER
The claims are directed to a turbomachine shroud and method for
reducing thermal generation between a shroud and a rotating component.
See Spec. 1—3. Claims 1, 14, and 27 are independent. Claim 1,
reproduced below, is illustrative of the claimed subject matter:
1. A turbomachine comprising:
a cylindrical shroud assembly having an inner surface and
an outer surface;
wherein said inner surface comprises a roughed ceramic
surface for contacting a rotating turbomachine component;
said roughed ceramic surface comprises a plurality of
raised portions protruding radially inward from said inner shroud
surface toward an axis defined by said shroud assembly, said
raised portions are arranged in a random arrangement across said
roughed ceramic surface; and
wherein said plurality of raised portions and said
cylindrical shroud assembly are a monolithic ceramic piece.
DISCUSSION
The Examiner finds that Habarou, Forrester, and Jackson disclose or
suggest all of the limitations of independent claims 1,14, and 27. See Final
Act. 4—5, 7—8, 9-10. In particular, the Examiner determines that it would
have been obvious “to modify the inner surface of the shroud assembly, as
taught by Habarou, by including the roughed surface, as taught by Forrester,
in order to provide [for] dulling the sharp comers and edges of impacting
blades.” Id. at 5, 7, 10 (citing Forrester 2:19—23; 5:43—45).
Appellants contend that in Habarou “[t]he inside surface 14 is not
contacted by the blades. Rather, the abradable layer 11 is contacted by the
blades. The function of the abradable layer 11 is to be worn away as the
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Appeal 2016-000432
Application 13/095,947
blade contacts the layer.” Appeal Br. 4. Appellants’ contention is supported
by Habarou which states:
in the usual way, a turbine ring is provided on its inside face with
a layer of abradable material with which the turbine tips can
come into contact without significant damage under the effect of
dimensional variations of thermal origin or as the result of the
centrifugal force that is applied to the blades.
Habarou 1:14—19 (emphasis added). Habarou further describes its ceramic
matrix composite (CMC) ring 10 stating:
On its inside peripheral surface 18, the ring 10 is provided with
a layer 11 of abradable material. In the example shown (see in
particular FIGS. 6, 7, and 8), the layer 11 is placed in a setback
14 formed in the inside surface 18 over the major fraction of the
width of the ring 10 in the axial direction.
Id. at 4:54—58. Thus, one skilled in the art would understand that the blade
contacting inner surface of Habarou’s CMC ring is made of an abradable
material in order to protect the blades from damage.
Given this understanding of Habarou’s CMC ring and the function of
the abradable material on its inner surface, Appellants argue that “[t]he
proposed modification would not have been obvious, at least because the
proposed rationale (to dull the sharp comers and edges of the impacting
blade) is incorrect.” Appeal Br. 4. To the extent that Appellants are arguing
that the proposed modification lacks rationale underpinning, we agree
because the proposed modification would render Habarou’s inner surface
unsatisfactory for its intended purpose of preventing damage to the blades.
See Harbarou 1:14—19. In relying on a combination of prior art references,
the Examiner's proposed modification cannot render a prior art reference
unsatisfactory for its intended purpose. In re Gordon, 733 F.2d 900, 902
(Fed. Cir. 1984). Thus, Appellants’ argument is persuasive.
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Appeal 2016-000432
Application 13/095,947
For this reason, we do not sustain the Examiner’s decision rejecting
independent claims 1, 14, and 27, and their respective dependent claims 2—4,
8-13, 15, 17, 18, 20, 23-26, 28, and 32-34.
DECISION
The Examiner’s rejection of claims 1—4, 8—15, 17, 18, 20, 23—28, and
32-34 is REVERSED.
REVERSED
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