Bintz, Matthew E. et al.

Patent Trials and Appeals Board

Nov 7, 2019

14422368 - (D) (P.T.A.B. Nov. 7, 2019)

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.
14/422,368 02/19/2015 Matthew E. Bintz 62594US02;
67097-2017PUS1
8493
54549 7590 11/07/2019
CARLSON, GASKEY & OLDS/PRATT & WHITNEY
400 West Maple Road
Suite 350
Birmingham, MI 48009
EXAMINER
MCCAFFREY, KAYLA M
ART UNIT PAPER NUMBER
3745
NOTIFICATION DATE DELIVERY MODE
11/07/2019 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 MATTHEW E. BINTZ, PETER T. SCHUTTE,
BRIAN J. SCHULER, and ANTHONY R. BIFULCO
____________

Appeal 2019-001918
Application 14/422,368
Technology Center 3700
____________

Before STEFAN STAICOVICI, WILLIAM A. CAPP and
MICHAEL L. WOODS, Administrative Patent Judges.

CAPP, Administrative Patent Judge.

DECISION ON APPEAL

STATEMENT OF THE CASE
Appellant1 seeks our review under 35 U.S.C. § 134(a) of the final
rejection of claims 1–18 and 20. We have jurisdiction under 35 U.S.C.
§ 6(b).
We REVERSE.

1 We use the word “Appellant” to refer to “Applicant” as defined in 37
C.F.R. § 1.42(a). Appellant identifies United Technologies Corporation as
the Applicant and real party in interest. Appeal Br. 1.
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THE INVENTION
Appellant’s invention relates to airfoils used in turbomachines. Spec.
¶¶ 2–3. Claim 1, reproduced below with paragraph indentation added, is
illustrative of the subject matter on appeal.
1. A cantilevered airfoil, comprising:
an airfoil having a body section and a tip,
the body section extending in a first direction that is angled
relative to a radial direction,
the tip of the airfoil angled radially in a second direction
relative to the body section,
wherein a centroid at the radially outermost section of the
airfoil is circumferentially offset from a centroid at the radially
innermost section of the airfoil such that the airfoil has a lean
relative to the radial direction,
the airfoil a cantilevered airfoil.
THE REJECTIONS
The Examiner relies upon the following as evidence in support of the
rejections:
Weingold
Bushnell
Baumann
Burton
US 5,088,892
US 2010/0119366 Al
US 7,726,937 B2
US 7,794,201 B2
Feb. 18, 1992
May 13, 2010
June 1, 2010
Sept. 14, 2010

The following rejections are before us for review:
1. Claims 1–4, 7–10, 18, and 20 are rejected under 35 U.S.C. § 103 as
being unpatentable over Baumann and Bushnell.
2. Claims 11–17 are rejected under 35 U.S.C. § 103 as being
unpatentable over Baumann, Bushnell, and Burton.
3. Claims 5 and 6 are rejected under 35 U.S.C. § 103 as being
unpatentable over Baumann, Bushnell, and Weingold.

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OPINION
Unpatentability of Claims 1–4, 7–10, 18, and 20
over Baumann and Bushnell
Claim 1
The Examiner finds that Baumann discloses a cantilevered airfoil
substantially as claimed except for being radially angled (or having
circumferential lean), for which the Examiner relies on Bushnell. Final
Action 4–6. The Examiner concludes that it would have been obvious to a
person of ordinary skill in the art at the time of the invention to impart a
circumferential lean, as taught by Bushnell, to the airfoil of Baumann to
achieve the claimed invention. Id. at 5. According to the Examiner, a person
of ordinary skill in the art would have done this to improve vane flow
separation control at the end wall region. Id. The Examiner considers such
to be a matter of using a known technique to improve a similar device in the
same way. Id. (citing KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398 (2007)).
Appellant argues that Bushnell’s airfoil is not cantilevered and that a
skilled person would not modify Baumann’s cantilevered airfoil based on
the teachings of Bushnell. Appeal Br. 4. Appellant notes that the outlet
guide vanes 18 of Bushnell, relied on by the Examiner as teaching
circumferential lean, are fixedly secured at each end and, thus, are not
cantilevered. Id. According to Appellant, the “rejection fails to provide any
factual basis demonstrating why the skilled person would apply the
teachings of airfoils that are not cantilevered to airfoils that are
cantilevered.” Id. Appellant augments this position by noting a lack of
evidentiary support for the Examiner’s finding that Baumann’s cantilevered
airfoil and Bushnell’s outlet guide vane are “similar devices.” Id.
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In response, the Examiner states that Baumann’s and Bushnell’s
devices are “similar,” because they are both in contact with a radially outer
wall and a radially inner wall during operation. Ans. 3. In particular, the
Examiner finds the vane of Baumann is secured at its radially outer end to a
radially outer wall and is in contact at its radially inner end with interdisk
spacer 62. Id. (citing Baumann, col. 3, ll. 45–47). The Examiner then
reasons as follows:
BUSHNELL teaches a row of rotating blades upstream of the
vanes produces a strong swirl flow that can result in excessive
flow separation at the outboard stations of the downstream
stator vanes (BUSHNELL paragraph 0008). By utilizing the
technique taught within BUSHNELL, i.e. circumferential lean,
an improvement in flow separation control is achieved
(BUSHNELL paragraphs 0009 and 0028). Therefore, with
rotating blades present upstream, an incoming swirl exists
whether or not the downstream vanes are cantilevered.
BAUMANN teaches a row of rotating blades (48) upstream of
the vanes. Thus, the Office asserts an incoming swirl that can
produce excessive flow separation at the radially inner end and
radially outer end of the cantilevered airfoil is present. Since,
the vane of BAUMANN is not only in contact at its outboard
stations but also has flow in the gas path at the outboard
stations, or end walls, with the flow in these locations being
effected by incoming swirl from the upstream rotating blades,
the Office maintains the vanes are similar devices.
Id. at 3–4.
In reply, Appellant points out that, notwithstanding the alleged inner
wall contact identified by the Examiner, Baumann’s radially inner wall is
moving (rotating) whereas Bushnell’s stator blades are stationary relative to
a radially inner wall. Reply Br. 2. Appellant further notes that Baumann’s
airfoils are within a high-pressure compressor whereas Bushnell’s stator
vanes are outlet guide vanes for a fan. Id. In essence, Appellant argues that
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that there is insufficient evidence that the airflow characteristics at
Baumann’s compressor vane and Bushnell’s fan vane are sufficiently similar
that a person of ordinary skill in the art would recognize that they would
each similarly benefit from having circumferential lean imparted to them.
Id. Furthermore, Appellant notes that the purpose of Bushnell’s vane is to
redirect swirl airflow into axial airflow. Id.
Baumann's airfoils 52 are not guiding flow from a fan. The
Bauman airfoils receive flow from the low speed compressor
section 26 and are spaced well away from the blade tips of the
fan 34. The Examiner has not shown that the flow from the low
speed compressor 26 exhibits the strong swirl flow, or that
controlling such flow with the Baumann airfoils 52 is even
desired. Further, the tip speed of the rotating blades in the low
speed compressor 26 would be much lower than the tip speed of
the rotating blades of the fan 34. This is another reason that the
swirl flow would not be an issue that the Baumann airfoils 52
would need to address. Baumann includes rotating blades, but
this does not mean that swirl flow f[ro]m those blades is an
issue. Swirl flow has not been shown to be an issue anywhere
other than in the specific environment of Bushnell.
Reply Br. 2–3.
Bushnell is directed to outlet guide vanes for axial flow fans.
Bushnell, Abstract. As fan blades 13 are rotated, the airflow moving toward
outlet guide vanes 18 has an axial component and a tangential component.
Id. ¶ 24. The function of Bushnell’s outlet guide vanes 18 is to remove the
tangential component (or “swirl”) and, to the extent possible, to redirect it in
the axial flow direction. Id. Bushnell acknowledges that some swirl losses
are inevitable, but states that its purpose is to reduce the swirl losses. Id.
Bushnell’s outlet guide vanes are secured at their radially inner ends to an
inner end wall and at their radially outer ends to casing. Id. ¶ 23.
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In contrast to the teaching of Bushnell, which is directed to airflow
characteristics over outlet guide vanes of the fan section of a turbofan
engine, Appellant’s invention is directed to reducing thermal energy that is
generated from high rubbing loads between the tips of cantilevered airfoils
and seal lands. Spec. ¶ 4. Thus, while Bushnell and Appellant both address
problems in the art by using circumferential lean, they address two distinct
problems. Bushnell redirects swirling airflow into axial airflow. Appellant
seeks to alleviate friction induced heat buildup.
We recognize that, for purposes of an obviousness analysis, a skilled
artisan need not be motivated to combine the prior art for the same reason as
an inventor. In re Kahn, 441 F.3d 977, 990 (Fed. Cir. 2006); see also
KSR,550 U.S. at 418-19, 420 (explaining that it is error to look only to the
problem the patentee was trying to solve). Nevertheless, we find
Appellant’s arguments rebutting the Examiner’s reasons to combine
Baumann and Bushnell to be persuasive. The Examiner has failed to show
that the airflow characteristics about Bushnell’s fixed, fan section, outlet
guide vane are sufficiently similar to the airflow about a cantilevered
compressor vane and rotating seal land that a person of ordinary skill in the
art would recognize that Baumann’s cantilevered airfoil would benefit from
circumferential lean.
In the foregoing regard, we note that, among other things, the
diameter of fan section blades and guide vanes is much greater than the
diameter of blades and guide vanes in the compressor section of an engine
and, therefore may experience higher tip speed. See, e.g., Bauman, Fig. 1.
Furthermore, converting swirling flow to axial flow at the outlet of a fan
section has a direct effect on overall thrust of the engine, whereas airflow
from a compressor section first enters a combustor and then a turbine section
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and then a nozzle before departing the engine casing. Id. Consequently,
there may be considerably less need to convert swirling flow to axial flow in
a compressor than in a fan section of a turbofan engine. All of these
considerations would impact whether a person of ordinary skill in the art
would have been motivated to redirect swirl to axial flow in Baumann’s
cantilevered airfoil.
In the final rejection, the Examiner nominally states a correct legal
principle. Final Action 5. It is generally correct that, if a technique has been
used to improve one device, and a person of ordinary skill in the art would
recognize that it would improve similar devices in the same way, using the
technique is obvious unless its actual application is beyond his or her skill.
KSR, 550 U.S. at 417. However, under the facts and circumstances of this
case, we are not persuaded that the compressor vanes of Baumann and the
fan outlet guide vanes of Bushnell are sufficiently similar that the foregoing
principal from KSR applies here.
In view of the foregoing discussion, we do not sustain the Examiner’s
unpatentability rejection of claim 1.
Claims 2–4 and 7–10
These claims depend, directly or indirectly, from claim 1. Claims
App. The Examiner’s rejection of these claims suffers from the same
infirmity that was identified above with respect to claim 1. Thus, for
essentially the same reason expressed above in connection with claim 1, we
do not sustain the rejection of claims 2–4 and 7–10.
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Claims 18 and 20
Claim 18 is an independent claim that is substantially similar in scope
to claim 1, and claim 20 depends therefrom. Claims App. The Examiner’s
rejection of these claims suffers from the same infirmity that was identified
above with respect to claim 1. Thus, for essentially the same reason
expressed above in connection with claim 1, we do not sustain the rejection
of claims 18 and 20.
Unpatentability of Claims 11–17
over Baumann, Bushnell, and Burton
Claim 11 is an independent claim that is substantially similar in scope
to claim 1 and claims 12–17 depend therefrom. Claims App. The
Examiner’s rejection of these claims suffers from the same infirmity that
was identified above with respect to claim 1. Thus, for essentially the same
reason expressed above in connection with claim 1, we do not sustain the
rejection of claims 11–17.
Unpatentability of Claims 5 and 6
over Baumann, Bushnell, and Weingold
These claims depend directly from claim 4 and indirectly from
claim 1. Claims App. The Examiner’s rejection of these claims suffers from
the same infirmity that was identified above with respect to claim 1, which
infirmity is not cured by the Examiner’s reliance on Wiengold. Thus, for
essentially the same reason expressed above in connection with claim 1, we
do not sustain the rejection of claims 5 and 6.
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CONCLUSION
In summary:
Claims
Rejected
35 U.S.C.
§
Reference(s)/Basis Aff’d Rev’d
1-4, 7-10, 18,
20
103 Baumann, Bushnell 1-4, 7-10, 18,
20
11-17 103 Baumann, Bushnell,
Burton
11-17
5, 6 103 Baumann, Bushnell,
Weingold
5, 6
Summary 1-18, 20

REVERSED