Ex Parte Praisner et al

Patent Trial and Appeal Board

Aug 21, 2018

12768822 (P.T.A.B. Aug. 21, 2018)

UNITED STA TES p A TENT AND TRADEMARK OFFICE
APPLICATION NO. FILING DATE
12/768,822 04/28/2010
52237 7590
Bachman & LaPointe, P.C.
900 Chapel St., Suite 1201
New Haven, CT 06510
08/21/2018
FIRST NAMED INVENTOR
Thomas J. Praisner
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
ATTORNEY DOCKET NO. CONFIRMATION NO.
0012452-US (09-392) 6348
EXAMINER
MCCAFFREY, KAYLA M
ART UNIT PAPER NUMBER
3745
MAIL DATE DELIVERY MODE
08/21/2018 PAPER
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.
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte THOMAS J. PRAISNER, MATTHEW B. ESTES,
and RENEE J. JUREK 1
Appeal2017-007751
Application 12/768,822
Technology Center 3700
Before WILLIAM A. CAPP, LEE L. STEPINA, and
RICHARD H. MARSCHALL, Administrative Patent Judges.
STEPINA, Administrative Patent Judge.
DECISION ON APPEAL
STATEMENT OF THE CASE
Appellants appeal under 35 U.S.C. § 134 from the Examiner's
decision to reject claims 5-9 and 11-14. We have jurisdiction under 35
U.S.C. § 6(b ).
We REVERSE.
1 The Appeal Brief identifies United Technologies Corporation as the real
party in interest. Appeal Br. 2.
Appeal2017-007751
Application 12/768,822
CLAIMED SUBJECT MATTER
The claims are directed to a high pitch-to-chord turbine airfoils.
Claim 5, reproduced below with emphasis added, is illustrative of the
claimed subject matter:
5. A geared gas turbine engine for propelling a vehicle, said
engme compnsmg:
a single geared gas turbine engine propulsive fan and at
least one geared gas turbine engine low pressure turbine stage;
said fan and said at least one low pressure turbine stage
being connected by a shaft;
a geared gas turbine engine gearbox incorporated into said
shaft, said gearbox configured to rotationally decouple said at
least one low pressure turbine stage and said shaft from said
single geared gas turbine engine propulsive fan, wherein said at
least one geared gas turbine low pressure turbine stage and said
shaft decouple to rotate at higher speed than said single geared
gas turbine engine propulsive fan; and
said at least one low pressure turbine stage being formed
by a disk portion, a plurality of low pressure turbine blades
extending outwardly from said disk portion, each of said low
pressure turbine blades having an airfoil portion with an axial
chord length and a trailing edge, and said turbine blades being
spaced apart so that there is a pitch-to-chord ratio greater than
1.4, wherein said pitch is a distance between the trailing edges of
adjacent ones of said turbine blades and said chord is the axial
chord length of said blades, and wherein said pitch-to-chord ratio
is measured at a mid-span of said blades, and said low pressure
turbine blades including a high velocity ratio, said high velocity
ratio being the ratio of the velocity of air exiting a turbine blade
outlet proximate the trailing edge compared to the velocity of the
air entering a low pressure turbine blade inlet opposite said outlet
of said blades.
Appeal Br. 18-19 (Claims App.).
2
Appeal2017-007751
Application 12/768,822
REFERENCES
The prior art relied upon by the Examiner in rejecting the claims on
appeal is:
Ferleger
Parker
Spangler
Grabowski
us 5,352,092
us 6,769,878
US 8,282,354 B2
WO 2008/063152 A2
REJECTIONS
Oct. 4, 1994
Aug.3,2004
Oct. 9, 2012
May 29, 2008
(I) Claims 5-7, 9, and 11-13 are rejected under 35 U.S.C. § 103(a)
as unpatentable over Grabowski, Ferleger, and Spangler. 2
(II) Claims 8 and 14 are rejected under 35 U.S.C. § 103(a) as
unpatentable over Grabowski, Ferleger, Spangler, and Parker.
OPINION
Rejection (!); Claims 5-7, 9, and 11-13
The Examiner finds that Grabowski includes most of the elements
required by independent claim 5, including, via inherency, that the turbine
blades provide a high velocity ratio. Final Act. 7-8. However, the
Examiner finds that Grabowski does not teach the range of pitch-to-cord
ratios recited in claim 5. Id. at 8. To remedy this deficiency, the Examiner
turns to Ferleger, finding that this reference teaches low pressure turbine
blades spaced apart so as to provide a pitch-to-chord ratio greater than 1.4
2 Although not listed in the heading for this rejection, the Examiner supports
the rejection of claims 5-7, 9 and 11-13 over Grabowski and Ferleger by
using Spangler as evidence that the weight of rotor blades is a concern.
Final Act. 8.
3
Appeal2017-007751
Application 12/768,822
(specifically, 1.463 as discussed in Table 1 of Ferleger). Id. The Examiner
finds that, although Ferleger operates with steam rather than air as
Grabowski does, both Grabowski and F erleger are concerned with reducing
rotor weight. Id. Citing Spangler, the Examiner finds that "it is commonly
known in the art of engine rotors that blade weight on the rotor is a
concern." Id. The Examiner determines that it would have been obvious to
a person of ordinary skill in the art "to arrange the low pressure turbine
blades of GRABOWSKI at a pitch-to-chord ratio greater than 1.4, as taught
by FERLEGER, in order to achieve the predictable results of a turbine with
a reduced number of blades in a row compared to conventional turbines."
Id. The Examiner finds that "[t]he reduced number of blades relates to a
reduced weight and centrifugal load on the rotor." Id. (citing Ferleger, 3:55-
56, 5:39-44).
Appellants contend that because the engine disclosed by Grabowski
uses air as a primary operating fluid, and the turbine disclosed by Ferleger
uses steam, a person of ordinary skill in the art would not have found it
obvious to use the pitch-to-chord ratios disclosed by Ferleger in the engine
disclosed by Grabowski. See Appeal Br. 10-16. Appellants rely on
declarations by Dr. Thomas J. Praisner and Renee Jurek (hereinafter, the
"Praisner Declaration" and the "Jurek Declaration"), submitted under 37
CPR§ 1.132, in support of this argument. See id. at 13. Both of the
Declarations contend that the blade configuration and design characteristics
of nuclear power plant low pressure steam turbines that use steam are very
3 The Examiner finds that the pitch-to-width ratio in Ferleger refers to the
same geometric relationship as the pitch-to-chord ratio recited in claim 5.
Final Act. 8.
4
Appeal2017-007751
Application 12/768,822
different from those that use air. Praisner Declaration ,r 11, Jurek
Declaration ,r 11.
In response, the Examiner states, "though steam is a different motive
fluid than air and as such has different thermo-fluid characteristics, all heat
engines ( whether they are steam turbines or gas turbines) operate under the
same principles of thermodynamics." Ans. 7. The Examiner also finds that
steam turbines and gas turbines have similar structure and concludes that a
person of ordinary skill in the art "would recognize the fluid characteristics
of that which they are using but also recognize the benefits of reducing
weight on the rotor thereby reducing centrifugal force on the rotor, as taught
by FERLEGER at column 5, lines 39--40, are universal and not dependent
upon the type of motive fluid." Id.
Although we appreciate the Examiner's position regarding the
similarity in operating principles of steam turbines and gas turbines, the
Examiner does not explain sufficiently how this similarity would result in
the implementation of the 1.46 pitch-to-chord ratio disclosed in Table 1 of
F erleger in the gas turbine of Grabowski. In this regard, we note that the
rejection is based upon Ferleger's explicit disclosure of a value within the
range of pitch-to-chord ratios recited in claim 5. See Final Act. 8. The
Praisner and Jurek Declarations indicate that the shape of the blades in a
turbine is dependent upon the working fluid and the environment. Thus, as
the 1.46 pitch-to-chord ratio disclosed by Ferleger relates to a different
working fluid and environment ( a steam turbine), we are not persuaded a
person of ordinary skill in the art would have found it obvious to use this
specific ratio in a non-steam turbine as disclosed by Grabowski.
Accordingly, we do not sustain the Examiner's rejection of claim 5, and
claims 6, 7, and 9 depending therefrom, as unpatentable over Grabowski,
5
Appeal2017-007751
Application 12/768,822
Ferleger, and Spangler. Independent claim 11 recites the same pitch-to-
chord ratio limitation as claim 5 (Appeal Br. 20 (Claims App.)), and, for the
same reasons discussed above regarding the rejection of claim 5, we do not
sustain the rejection of claim 11 and claims 12 and 13 depending therefrom.
Rejection (II); Claims 8 and 14
The Examiner's use of Parker does not remedy the deficiency in the
rejection of independent claims 5 and 11. See Final Act. 11. Accordingly,
we do not sustain the rejection of claims 8 and 14 as unpatentable over
Grabowski, Ferleger, Spangler, and Parker.
DECISION
The Examiner's decision to reject claims 5-9 and 11-14 is reversed.
REVERSED
6