Ex Parte Chambers et al

Patent Trial and Appeal BoardOct 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 Appeal 2010-007018 Application 11/056,185 2 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 Appeal 2010-007018 Application 11/056,185 3 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 Appeal 2010-007018 Application 11/056,185 4 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.”) Appeal 2010-007018 Application 11/056,185 5 “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 Appeal 2010-007018 Application 11/056,185 6 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. Appeal 2010-007018 Application 11/056,185 7 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 hh