Ex Parte Houston et al

Patent Trial and Appeal Board

Aug 29, 2017

13309685 (P.T.A.B. Aug. 29, 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.
13/309,685 12/02/2011 David P. Houston 67097-1617FUSl;58493US01 1099
54549 7590 08/31/2017
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
08/31/2017 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 DAVID P. HOUSTON, RICHARD A. LOMENZO,
and ROBERT J. MORRIS
Appeal 2015-007958
Application 13/309,685
Technology Center 3700
Before JENNIFER D. BAHR, EDWARD A. BROWN, and
ARTHUR M. PESLAK, Administrative Patent Judges.
BAHR, Administrative Patent Judge.
DECISION ON APPEAL
STATEMENT OF THE CASE
David P. Houston et al. (Appellants)1 appeal under 35 U.S.C. § 134(a)
from the Examiner’s decision rejecting claims 1—18. We have jurisdiction
under 35 U.S.C. § 6(b).
We AFFIRM.
1 The Appeal Brief identifies United Technologies Corporation as the real
party in interest. Appeal Br. 1.
Appeal 2015-007958
Application 13/309,685
THE CLAIMED SUBJECT MATTER
Claim 11, reproduced below, is representative of the claimed subject
matter.
11. A gas turbine engine stator having a plurality of airfoils
extending radially inwardly therefrom, said stator comprising:
a base from which said airfoils extend to an unshrouded
free end, and
slits disposed in said base, each slit disposed between a
pair of airfoils, wherein a distance between a first set of adjacent
slits and a distance between a second set of adjacent slits varies.
REJECTIONS
I. Claims 1—9, 11—16, and 18 stand rejected under 35 U.S.C. § 103(a)
as unpatentable over Langer (US 4,365,933, issued Dec. 28, 1982),
Lasche (US 1,534,721, issued Apr. 21, 1925), and Schirle
(US 2006/0198726 Al, published Sept. 7, 2006).
II. Claims 10 and 17 stand rejected under 35 U.S.C. § 103(a) as
unpatentable over Langer, Lasche, Schirle, and Buxe
(US 4,422,827, issued Dec. 27, 1983).
DISCUSSION
Rejection I
Appellants group claims 1—9, 11—16, and 18 subject to this rejection
together in contesting the rejection. Appeal Br. 3^4. We select claim 11 as
representative of this group in deciding the appeal of this rejection, with
claims 1—9, 12—16, and 18 standing or falling with claim 11. See 37 C.F.R.
§ 41.37(c)(l)(iv).
The Examiner finds that Langer discloses a stator as called for in
claim 11, including a base (outer cover ring 4) provided with slits, and a
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Application 13/309,685
plurality of airfoils (vanes 2) extending from the base, but that Langer does
not teach (i) varying the distance between a first set of adjacent slits and a
second set of adjacent slits or (ii) the airfoils extending from the base to an
unshrouded free end. Final Act. 3. The Examiner determines it would have
been obvious, in view of Lasche, to modify Langer by varying the spacing
between adjacent blades (i.e., vanes or airfoils), and, thus, the spacing
between the slits, in order to avoid the occurrence of a resonant condition
and, thereby, extend the life of the blades. Id. Appellants do not contest
either the Examiner’s findings regarding Lasche or the determination that
such a modification would have been obvious. See Appeal Br. 3^4
(contesting only the modification to remove one of the rings, in view of
Schirle).
The Examiner finds that Schirle teaches a finite number (i.e., two) of
ways to attach airfoils to shrouds in a stator, the first being an embodiment
in which the airfoils are bound by an inner shroud and an outer shroud, as
illustrated in Figure 5, and the second being an embodiment in which the
airfoils have a free tip at an unshrouded end, as illustrated in Figure 6. Final
Act. 3; Ans. 6. The Examiner determines that “[sjince Langer and S[c]hirle
each teach a finite number of ways to attach airfoils to shrouds, it would
have been obvious to ... try to build” Langer’s stator with the blades having
an unshrouded free end, as taught by Schirle, because “a person with
ordinary skill has good reason to pursue the known options within his or her
technical grasp.” Final Act. 3.
Appellants assert that “[t]he modification proposed by the Examiner
would remove the outer ring 4 from Langer.” Appeal Br. 3. Based on our
review of the record, this assertion mischaracterizes the Examiner’s
rejection. The Figure 6 embodiment of Schirle relied on by the Examiner as
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Application 13/309,685
including airfoils having a free tip at an unshrouded end depicts each of
stator blades 64 extending from an outer casing to an unshrouded free end.
See Schirle, Fig. 6,116 (disclosing that “the tip of stator blade 64 is spaced
from [inner] casing 60”). Moreover, the Examiner characterizes the
proposed modification as “modifying] Langer by removing the inner ring as
taught by Schirle.” Final Act. 2 (emphasis added).
Appellants argue that the proposed modification of Langer in view of
Schirle would change the principle of operation of Langer, and, thus, would
not have been obvious. Appeal Br. 3. In particular, Appellants contend that
“[eliminating the outer ring 4 from Langer . . . would change the principle
of operation of Langer because Langer is directed to a method of addressing
challenges that arise from manufacturing a vane with both an inner and outer
ring.” Id.
Appellants’ argument is unpersuasive, for essentially the reasons set
forth by the Examiner on pages 3^4 of the Answer. Notably, although
Langer discusses the invention disclosed therein particularly in the context
of vane rings for gas turbine engines composed of vanes extending between
radially inner and outer cover rings, Langer also states, more broadly, that
the invention “relates to turbine vane rings.” Langer, col. 1,11. 6—9. As the
Examiner points out, Langer’s invention provides slits in the vane rings
between adjacent vanes to address the challenge of heat stresses, without
sacrificing aerodynamics and manufacturing capability. Ans. 4; Langer, col.
1,11. 47—53. Appellants do not identity, nor do we discern, any teachings in
Langer that suggest that either the challenges addressed by Langer or the
solutions to address those challenges are unique to stators having vanes
extending between radially inner and outer cylindrical cover rings, and are
not of relevance in a stator having only one ring. Thus, even accepting
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Application 13/309,685
Appellants’ position as to what the “principle of operation” of Langer is, the
modification proposed by the Examiner (eliminating the inner ring) will not
change this “principle of operation.”
Moreover, the “principle of operation” referred to by Appellants
relates to the “basic principles” under which the prior art device was
designed to operate. In re Ratti, 270 F.2d 810, 813 (CCPA 1959) (“This
suggested combination of references would require a substantial
reconstruction and redesign of the elements shown in [the primary reference]
as well as a change in the basic principles under which the [primary
reference] construction was designed to operate.”) (emphasis added). As the
Examiner points out, Langer’s stator will operate in the same manner to
extract useful work out of a gas flow, in an improved manner to better
withstand heat stresses, whether the vanes are attached to both an inner and
outer ring or to only an outer ring. Ans. 3.
Appellants also argue that “[eliminating the outer ring 4 from Langer
would make Langer unsuitable for its intended purpose of addressing the
challenges that arise from manufacturing vanes with both inner and outer
rings.” Appeal Br. 4. This argument is unpersuasive for essentially the
reasons set forth by the Examiner on page 5 of the Answer.
Appellants do not identify, nor do we discern, any teachings in Langer
suggesting that the stator, modified to include only an outer ring, as taught
by Schirle, would be unsuitable for its intended purpose—providing an
aerodynamic stator construction that is easy to fabricate and capable of
withstanding the heat stresses it experiences when subjected to high
temperature gas flows in a gas turbine. See Langer, col. 1,11. 10—53.
Finally, Appellants take issue with the Examiner’s application of the
“obvious to try” rationale. Appeal Br. 4; Reply Br. 2. In particular,
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Application 13/309,685
Appellants submit that the Examiner fails to satisfy the burden of
establishing that there are only a finite number of identified and predictable
solutions for arranging the airfoils. Appeal Br. 4.
The Examiner counters that “[t]he references presented only show two
possible ways of supporting the blade: via an inner and outer ring or via a
single ring.” According to the Examiner, “[s]ince two is a finite number[,] it
is unclear how Appellants] can construe it otherwise.” Ans. 6.
The Supreme Court has stated:
When there is a design need or market pressure to solve a
problem and there are a finite number of identified, predictable
solutions, a person of ordinary skill has good reason to pursue
the known options within his or her technical grasp. If this leads
to the anticipated success, it is likely the product not of
innovation but of ordinary skill and common sense. In that
instance the fact that a combination was obvious to try might
show that it was obvious under § 103.
KSRInt’l Co. v. Teleflex Inc., 550 U.S. 398, 421 (2007).
In a stator for a gas turbine, the radially extending
blades/vanes/airfoils must be supported in a circumferentially spaced
manner. The Examiner finds that, as illustrated, for example, by Schirle, this
can be done in only two ways—by either fixing both ends of the
blades/vanes/airfoils in a ring (annular structure) or by fixing only one end
of the blades/vanes/airfoils in a ring, with the other ends being unshrouded,
free ends, in a cantilevered manner. Ans. 6; see Schirle Tflf 4, 5, 16, Figs. 5
and 6. Appellants assert that the Examiner has not established that there are
only a finite number of ways to support the blades, but does not positively
assert that there are other possibilities, much less identify any such other
possibilities, other than the two disclosed by Schirle (two fixed ends or one
fixed end and one free end) and mentioned by the Examiner. As such,
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Appellants do not apprise us of error in the Examiner’s finding in this
regard.
For all of the above reasons, Appellants do not apprise us of error in
the Examiner’s determination that the subject matter of claim 11 would have
been obvious. Accordingly, we sustain the rejection of claim 11, as well as
claims 1—9, 12—16, and 18, which fall with claim 11, as unpatentable over
Langer, Lasche, and Schirle.
Rejection II
Appellants do not present any separate arguments for claims 10 and
17, aside from their dependence from independent claims 1 and 11,
respectively. Appeal Br. 4. Thus, for the reasons set forth above, we also
sustain the rejection of claims 10 and 17 as unpatentable over Langer,
Lasche, Schirle, and Buxe.
DECISION
The Examiner’s decision rejecting claims 1—18 is AFFIRMED.
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)(l)(iv).
AFFIRMED
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