General Electric Company

Patent Trials and Appeals Board

Nov 2, 2021

2020006059 (P.T.A.B. Nov. 2, 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.
14/659,640 03/17/2015 Ronald Scott BUNKER 278943-US-1 1528
91753 7590 11/02/2021
McGarry Bair PC / General Electric Company
45 Ottawa Ave. SW
Suite 700
Grand Rapids, MI 49503
EXAMINER
HUNTER, JOHN S
ART UNIT PAPER NUMBER
3745
NOTIFICATION DATE DELIVERY MODE
11/02/2021 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):
OC.Prosecution@ge.com
patents@mcgarrybair.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE PATENT TRIAL AND APPEAL BOARD
____________

Ex parte RONALD SCOTT BUNKER, FREDERICK ALAN BUCK,
ROBERT DAVID BRIGGS, GULCHARAN SINGH BRAINCH, and
KEVIN ROBERT FELDMANN
____________

Appeal 2020-006059
Application 14/659,640
Technology Center 3700
____________

Before MICHAEL C. ASTORINO, CYNTHIA L. MURPHY, and
TARA L. HUTCHINGS, Administrative Patent Judges.

HUTCHINGS, Administrative Patent Judge.

DECISION ON APPEAL
STATEMENT OF THE CASE
Appellant1 appeals under 35 U.S.C. § 134(a) from the Examiner’s
rejection of claims 1–7 and 9–20. We have jurisdiction under 35 U.S.C.
§ 6(b).
We REVERSE.

1 We use the term “Appellant” to refer to “applicant” as defined in 37 C.F.R.
§ 1.42. Appellant identifies General Electric Company as the real party in
interest. Appeal Br. 2.
Appeal 2020-006059
Application 14/659,640

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CLAIMED INVENTION
Appellant’s claimed invention relates “broadly to film-cooled engine
components, particularly in a gas turbine engine.” Spec. ¶ 3.
Claims 1 and 18 are the independent claims on appeal. Claim 1,
reproduced below, is illustrative of the claimed subject matter:
1. An engine component for a gas turbine engine, the
gas turbine engine generating hot combustion gas flow,
comprising:
a substrate having a hot surface facing the hot combustion
gas flow and a cooling surface facing a cooling fluid flow, the
hot combustion gas flow defining an upstream direction and a
downstream direction relative to the hot surface; and
a film hole extending through the substrate and defining a
centerline, and comprising:
a metering section defining a metering diameter D and
extending between an inlet of the metering section and an outlet
of the metering section corresponding to a downstream end of
the metering section where the centerline passes through a
geometric center of the metering section; and
a diffusing section extending between an inlet of the
diffusing section and an outlet of the diffusing section where the
inlet of the diffusing section is coincident with the outlet of the
metering section to define a transition and having a downstream
boundary surface and an upstream boundary surface;
wherein the transition marks the downstream end of the
metering section where a diameter of the film hole begins to
increase and the diffusing section defines a hooded length L as
the distance along the upstream boundary surface between the
transition and the hot surface; and
wherein 2 ≤ L/D ≤ 6 the L/D having a value within a
corresponding blowing ratio range associated with the film hole.

Appeal Br. 17 (Claims Appendix).

Appeal 2020-006059
Application 14/659,640

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REJECTION
Claims 1–7 and 9–20 are rejected under 35 U.S.C. § 103 as
unpatentable over Mongillo (US 8,850,828 B2, iss. Oct. 7, 2014) and
Brittingham (US 8,057,182 B2, iss. Nov. 15, 2011).

ANALYSIS
Independent Claim 1, and Dependent Claims 2–7 and 9–17
Claim 1 recites that the hooded length L and metering diameter satisfy
the relationship: “2 ≤ L/D ≤ 6” and that “L/D has a value within a
corresponding blowing ratio range associated with the film hole.” For
example, a hood ratio L/D value of 2 is within a corresponding blowing ratio
range of 0.5 to 3; a hood ratio L/D value of 4 is within a corresponding
blowing ratio range of 2.5 to 5; and a hood ratio L/D value of 6 is within a
corresponding blowing ratio range of 4.5 to 10. Spec. ¶ 44, Table 1.
Appellant’s Specification describes the significance of tying a value
of L/D to a corresponding range of blowing ratios. See Spec. ¶¶ 44–48. In
particular, Appellant’s Specification describes that if L/D is too small
relative to the blowing ratio, the cooling fluid will not diffuse enough and a
core portion of the cooling fluid flow will interact with hot combustion gas
flow, leading to undesirable mixing and loss of film cooling effectiveness.
Spec. ¶ 44. In contrast, if L/D is too large relative to the blowing ratio, the
cooling fluid will be excessively heated within the cooling hole, also leading
to decreased film effectiveness. Id.; see also id. at Table 1 (identifying L/D
values, each L/D value having a corresponding range of blowing ratios).
In rejecting claim 1 under 35 U.S.C. § 103, the Examiner primarily
relies on Mongillo as disclosing the recited claim limitations. See Final
Appeal 2020-006059
Application 14/659,640

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Act. 7. Mongillo teaches an improved cooling hole (including an inlet, a
metering section, a diffusing section, and an outlet) in a gas turbine engine
component. Mongillo Abstract. Metering section 112 has a hydraulic
diameter (“dh”), diffusing section 114 has a hooded length L, and the two are
related according to “dh/4 < L < 2dh,” which corresponds to ¼ < L/D < 2.
See id. at Fig. 4, 7:47–48, 8:46–50. Mongillo further teaches that the
improved cooling holes “provide improved film cooling at any blowing
ratio, but are particularly suited for blowing ratios between about 0.5
and 10.” Id. at 11:21–27.
The Examiner acknowledges that Mongillo fails to teach that the film
hole has a ratio of a hooded length L to a metering diameter D (i.e., “L/D”)
that is “2 ≤ L/D ≤ 6” and that L/D has “a value within a corresponding
blowing ratio range associated with the film hole,” as recited in claim 1. See
Final Act. 8. To help cure the deficiency, the Examiner turns to
Brittingham. See id. Brittingham relates to improved film cooling of
components in gas turbine engines. Brittingham 1:6–8. An airfoil 16
includes a plurality of radial extending metered cooling slots 52. Id. at 4:35–
38. Each metered cooling slot 52 generally includes slot 54, extending
substantially the full radial length of airfoil 16, and one or more metering
apertures 55 of the arrangement shown in Figure 4. Id. at 4:41–43, 5:7–10,
Fig. 4. Slot 54 and metering aperture 55 intersect at a relatively steep angle
to produce impingement cooling at the slot surface and to spread coolant
fluid within slot 54. Id. at 5:54–61. A diameter of the metering aperture 55
(“D”) and a distance from the center line of metering aperture 55 to an outlet
of slot 54 (“L1”) have an L1/D ratio preferably greater than about 7 and,
more preferably, greater than about 8. Id. at 7:11–20. Blowing ratios (“M”)
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Application 14/659,640

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between 0.41 and 0.64 were used to measure adiabatic effectiveness as a
function of L1/D. See id. at Fig. 6; see also id. at 7:2–22.
The Examiner acknowledges that Brittingham also does not teach the
argued claim limitations. See Ans. 3 (explaining that the Examiner “does
not rely on the particular resultant values of the L1/D geometry and blowing
ratio M of Brittingham”). Instead,the Examiner finds that Brittingham L1/D
is equivalent to the claimed L/D, and that Brittingham teaches that L1/D
impacts the cooling results and that the blowing ratio is an important
consideration in an optimization process for the ratio of L1/D. See Final
Act. 8. The Examiner then determines that
[i]t would have been obvious . . . to perform routine
experimentation with at least the values for the L/D ratio and the
blowing ratio of the film cooling hole of Mongillo based on the
recognition and teachings of Brittingham to optimize the
particular geometry based on the recognition and teachings of
Brittingham to optimize the particular geometry in order to result
in optimized cooling for the film hole of Mongillo, as according
to MPEP 2144.05.II.B, the presence of a known result-effective
variable would be one, but not the only, motivation for a person
of ordinary skill in the art to experiment to reach another
workable product or process, and for the result of the
optimization of Mongillo to result in the L/D ratio falling within
the same range as claimed by applicant, as Brittingham teaches
to optimize the cooling for the same reasoning as expressed by
applicant, and such optimization would result in a corresponding
blow ratio for the optimized cooling hole geometry, and the
results of such a modification would have been obvious as
discussed above.
Id.; see also Ans. 4 (finding that “Brittingham explicity teaches that L/D and
blowing ratio are result-effective variables,” such that it would have been
obvious to optimize these result-effective variables for Mongillo’s cooling
holes). The Examiner does not address, on the record, how the combination
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of Mongillo and Brittingham teaches that a value of L/D is within a
corresponding blowing ratio, as required by claim 1. One way the Examiner
could address this limitation is by showing that one of the prior art
references teaches that for an L/D of 5, the blowing ratio also is
approximately 5. See Spec. ¶ 44; but see Brittingham, 7:14–22, Fig. 6
(describing that an L/D ratio greater than 7 achieve a relatively high
adiabatic cooling effectiveness for blowing ratios of 0.41, 0.52, and 0.64);
Mongillo 11:21–26 (teaching that any blowing ratio may be used for
improved cooling). As best we understand the rejection, the Examiner
determines that L/D and the blowing ratio are both result effective variables,
and determines that it would have been obvious to perform routine
experimentation to optimize each variable independently from the other and
that this optimization would have resulted in the value for L/D falling within
the claimed range and within a corresponding blowing ratio range. Final
Act. 8; see also Ans. 3–5.
We determine that the Examiner’s analysis and the evidence provided
fall short of adequately explaining why a person of ordinary skill would
have arrived at the invention through routine optimization. The Examiner
does not address why one of ordinary skill in the art, seeking to optimize
cooling for Mongillo’s film hole, would modify the L/D ratio of Mongillo’s
film hole to have a value within a corresponding blowing ratio range, as
required by claim 1, much less does the Examiner explain why it would have
been obvious to optimize this correspondence as a matter of routine
optimization to arrive at the claimed range between 2 and 6. See Appeal
Br. 11–16. Accordingly, we determine that the Examiner’s analysis and the
evidence provided fall short of adequately explaining why a person of
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ordinary skill would have arrived at the invention through routine
optimization without impermissible hindsight. Therefore, we do not sustain
the rejection of independent claim 1, and dependent claims 2–7 and 9–17
under 35 U.S.C. § 103.
Independent Claims 18, and Dependent Claims 19 and 20
Independent claim 18 recites language similar to independent claim 1,
and the Examiner’s rejection of these claims under 35 U.S.C. § 103 are
based on the same erroneous rationale described above with respect to
claim 1. See Final Act. 13. Therefore, we do not sustain the rejection of
independent claim 18, and dependent claims 19 and 20 under 35 U.S.C.
§ 103 for the same reasons set forth above with respect to claim 1.

CONCLUSION
In summary:
Claims
Rejected
35 U.S.C.
§
References/Basis Affirmed Reversed
1–7, 9–20 103 Mongillo,
Brittingham
1–7, 9–20

REVERSED