Ex Parte Chambers et al

Patent Trial and Appeal Board

Oct 29, 2012

11056185 (P.T.A.B. Oct. 29, 2012)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________________

BEFORE THE PATENT TRIAL AND APPEAL BOARD
____________________

Ex parte ANDREW CHAMBERS, PETER IRELAND,
DAVID R.H. GILLESPIE, and GEOFFREY M. DAILEY
____________________

Appeal 2010-007018
Application 11/056,185
Technology Center 3700
____________________

Before: KEN B. BARRETT, PHILLIP J. KAUFFMAN, and
WILLIAM V. SAINDON, Administrative Patent Judges.

SAINDON, Administrative Patent Judge.

DECISION ON APPEAL
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STATEMENT OF THE CASE
Appellants appeal under 35 U.S.C. § 134 from the Examiner’s
decision rejecting claims 1, 2, 4-11, and 13-15. We have jurisdiction under
35 U.S.C. § 6(b).

The Claimed Subject Matter
The claims are directed to an impingement cooling passage formed
between a target surface to be cooled and a junction surface having coolant
jet apertures. Cooling fluid flows from the jets and impinges on the target
surface. Spec. 5:31 to 6:4; fig. 3. A projection upstream of the jet aperture
limits localized flow distortion from coolant flow further upstream
(essentially, it acts as a wind block). Spec. 9:7 to 10:5; fig. 3. The
projection extends from the target surface toward the junction surface more
than halfway. Clm. 1. There is a pressure drop penalty associated with the
projection extending closer towards the junction plate, but the benefit of the
projection is to shield the incoming jetted fluid from the cross flow, to allow
the jetted fluid to strike the target surface in a manner that increases heat
exchange, as well as to provide additional surface area available for heat
transfer. Spec. 10:6-28. Claim 1, reproduced below, is illustrative of the
claimed subject matter.
1. An impingement cooling arrangement for an engine, the
arrangement comprising:
a coolant passage with a jet aperture, the coolant passage
including a target surface, wherein, in use, a coolant flow jetted
through the jet aperture is directed for heat transfer towards the
target surface, wherein the target surface includes a projection
upstream of the jet aperture directed towards a junction surface
including the jet aperture such that an end of the projection is
spaced from the junction surface to limit localized flow
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distortion about the jet aperture whilst providing a flow wake
downstream of the projection which in use allows for a more
consistent coolant flow directed towards the target surface due
to less cross-flow deflection, and wherein a distance between
the junction surface and the end of the projection is less than
half a distance between the junction surface and the target
surface.

References
The Examiner relies upon the following prior art references:
Dodd
Butts
Halfmann
US 4,105,364
US 5,232,343
US 6,974,308 B2
Aug. 8, 1978
Aug. 3, 1993
Dec. 13, 2005

Rejections
I. Claims 1, 2, 5-10, and 13-15 are rejected under 35 U.S.C. § 103(a) as
unpatentable over Dodd and Butts.
II. Claims 4 and 11 are rejected under 35 U.S.C. § 103(a) as unpatentable
over Dodd, Butts, and Halfmann.

SUMMARY OF DECISION
We AFFIRM.

OPINION
The Examiner found that Dodd describes the impingement cooling
device of claim 1, except for the limitation that the projections are spaced
from the junction surface. Ans. 3-4. The Examiner found that Butts
describes projections that extend partially between opposing sidewalls (of a
fluid cooling device). Ans. 4. The Examiner found that Butts describes
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such projections as increasing the turbulence in order to increase heat
exchange. Ans. 7.
Appellants argue claims 1, 2, 5-10, and 13-15 as a group (App. Br. 16-
31; Reply Br. 2-12); we select claim 1 as representative. Appellants present
a host of arguments that challenge whether the Examiner properly combined
Dodd and Butts, largely because of the differences between those references.
See, e.g., App. Br. 18-20 (design goals different), 20-22 (no problems with
Dodd’s pedestals, no motivation in Butts), 22-25 (reduce heat transfer,
increase turbulence), 25-26 (Butts’ turbulators are not Dodd’s projections).1
In pertinent part, Appellants focus on the fact that Dodd and Butts facially
utilize projections differently: to block airflow for a cooling jet in an
impingement plate (Dodd) and to increase turbulence in a serpentine passage
(Butts). See, e.g., App. Br. 18-20. Appellants have not, however, apprised
us of why this would impede the Examiner’s proposed combination.
The evidence of record supports the Examiner’s proposed
combination. Butts describes ways to cool turbine blades using turbulators
and/or pins. Butts, col. 1, ll. 26-47. Notably, as the Examiner points out, the
pins may “extend partly or completely between opposing sidewalls of the
blade.” Ans. 4, 5-6 (emphasis removed) (citing Butts, col. 1, ll. 26-38); see
also Butts, col. 4, ll. 9-45 (similarly describing the turbulators extending
partially between the walls). Butts adds that the turbulators and pins

1 Appellants’ arguments that the references do not explicitly acknowledge a
problem with the Dodd invention or explicitly suggest/motivate the
combination (Ans.; Reply Br., passim) are unpersuasive at the outset. See
KSR Int’l Co. v. Teleflex, Inc., 550 U.S. 398, 419 (2007) (“The obviousness
analysis cannot be confined by a formalistic conception of the words
teaching, suggestion, and motivation, or by overemphasis on the importance
of published articles and the explicit content of issued patents.”)
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“improve[e] heat transfer” and also describes mixing serpentine passage-
type cooling with impingement-type cooling. Butts, col. 1, ll. 43-47.
Finally, Butts discusses that determining how far a turbulator extends
between the walls requires a tradeoff between heat transfer vs. pressure loss
(flow blockage). Butts, col. 4, ll. 16-28.
In view of these teachings of Butts, we are not apprised of error in the
Examiner’s reasoning in combining the teachings of Dodd and Butts. The
Examiner points to the fact that the proposed modification (non-fully
extending pins) is known (Ans. 5-6) and would provide increased heat
transfer as taught in Butts (Ans. 7). While tradeoffs are required in
balancing the benefits of increased heat transfer with protection of the
impingement jet, such tradeoffs do not appear to be outside the level of
ordinary skill. Winner Int'l Royalty Corp. v. Wang, 202 F.3d 1340, 1349 n.8
(Fed. Cir. 2000) (“The fact that the motivating benefit comes at the expense
of another benefit, however, should not nullify its use as a basis to modify
the disclosure of one reference with the teachings of another. Instead, the
benefits, both lost and gained, should be weighed against one another.”).
Here, the length of the projection dictates a tradeoff between providing a lee
for the impingement jet as discussed in Dodd with the increased heat transfer
vs. pressure loss tradeoff of Butts. Reading the references in combination, it
would be clear to a person of ordinary skill in the art that a longer projection
provides a better ability to allow the impingement jet to strike the target
surface, but at the cost of reduced cross-flow pressure and reduced ability of
the cross flow to provide heat transfer. That Butts does not explicitly
discuss whether the pins not completely spanning the walls are also used for
protecting impingement jets does not negate the fact that Butts nevertheless
explicitly describes this pin structure and instructs its tradeoffs (pressure
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loss, heat transfer). One of ordinary skill in the art is well-educated in the
mechanics of fluid flow and has the ability to understand the effects of
manipulating pin/turbulator size. See, e.g., Spec. 11:4-8, 14-24 (describing
how determining the appropriate sizing of the projection/gap and resulting
airflow would be understood by one of ordinary skill in the art, without
setting forth any technical explanation); Hybritech, Inc. v. Monoclonal
Antibodies, Inc., 802 F.2d 1367, 1384 (Fed. Cir. 1986) (“a patent need not
teach, and preferably omits, what is well known in the art.”) (citing
Lindemann Maschinenfabrik GMBH v. Am. Hoist & Derrick, 730 F.2d 1452,
1463 (Fed. Cir. 1984)). Accordingly, we are not apprised of error in the
Examiner’s reasoning.
Appellants additionally argue that Butts shows the turbulators to be
less than halfway from the opposite wall. App. Br. 29-31. However, this
argument fails to address the Examiner’s rejection. The Examiner found
that one of ordinary skill in the art would have considered the spacing from
the junction surface to be an engineering expedient. Ans. 4. Appellants do
not persuasively traverse this finding, and given the aforementioned
discussion in Butts discussing this relationship and its tradeoffs, we are not
apprised of error in the Examiner’s finding.
In view of the above, we are not apprised of error in the Examiner’s
rejection of claim 1. Claims 2, 5-10, and 13-15 fall therewith. Appellants
separately address claims 4 and 11 but rely on the unpersuasive arguments
addressed above. App. Br. 31-32.

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DECISION
We sustain the Examiner’s decision regarding claims 1, 2, 4-11, and
13-15. No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a)(1)(iv).

AFFIRMED

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