PRATT & WHITNEY CANADA CORP.

Patent Trials and Appeals BoardOct 6, 2020

2020000799 (P.T.A.B. Oct. 6, 2020)

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. 14/287,125 05/26/2014 Mark Huzzard CUNNINGHAM 05002993-1704US WHY/sa 2751 32292 7590 10/06/2020 NORTON ROSE FULBRIGHT CANADA LLP (PWC) 1, PLACE VILLE MARIE SUITE 2500 MONTREAL, QUEBEC H3B 1R1 CANADA EXAMINER BURKE, THOMAS P ART UNIT PAPER NUMBER 3741 NOTIFICATION DATE DELIVERY MODE 10/06/2020 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): NRFCUSPTOMAIL@nortonrosefulbright.com ipcanada@nortonrosefulbright.com PTOL-90A (Rev. 04/07) UNITED STATES PATENT AND TRADEMARK OFFICE BEFORE THE PATENT TRIAL AND APPEAL BOARD Ex parte MARK HUZZARD CUNNINGHAM, EDWARD PARKER VLASIC, and SAMI GIRGIS Appeal 2020-000799 Application 14/287,125 Technology Center 3700 BEFORE STEFAN STAICOVICI, JEREMY M. PLENZLER, and SUSAN L. C. MITCHELL, Administrative Patent Judges. PLENZLER, Administrative Patent Judge. DECISION ON APPEAL STATEMENT OF THE CASE Pursuant to 35 U.S.C. § 134(a), Appellant1 appeals from the Examiner’s decision to reject claims 1, 3, 5–10, 12, and 13. We have jurisdiction under 35 U.S.C. § 6(b). We AFFIRM. 1 We use the word Appellant to refer to “applicant” as defined in 37 C.F.R. § 1.42(a). Appellant identifies the real party in interest as Pratt and Whitney Canada Corp. Appeal Br. 2. Appeal 2020-000799 Application 14/287,125 2 CLAIMED SUBJECT MATTER The claims are directed to a turbine exhaust case. Claim 1, reproduced below, is illustrative of the claimed subject matter: 1. A turbine exhaust case (TEC) of a turbofan aeroengine including a mixer for mixing exhaust gases with a bypass air stream, the TEC comprising an annular hub and an annular shroud with said mixer located at a downstream end of the annular shroud, the mixer surrounding the annular hub to form an annular exhaust gas duct positioned radially therebetween, the mixer having an annular wavy configuration to form a plurality of axially extending lobes of the mixer, the plurality of axially extending lobes defining alternating crests and valleys extending divergently to a downstream end of the mixer, a plurality of deswirling struts circumferentially spaced apart with respect to a central axis of the TEC and located within an axial length of the mixer between an upstream end where exhaust gases enter the mixer and the downstream end of the mixer where exhaust gases are discharged from the mixer and mix with the bypass air stream, leading edges of the deswirling struts being either axially aligned with, or located downstream of, a start point where the divergently extending crests and valleys start to extend away from each other, each of the deswirling struts having a cambered profile and extending radially across the annular exhaust gas duct and interconnecting the mixer and the annular hub, the deswirling struts cambered in a direction of an incoming swirling flow of the exhaust gases such that a concave side of the cambered profile faces the incoming swirling flow. REFERENCES The prior art relied upon by the Examiner is: Name Reference Date Ramm US 2010/0031631 A1 Feb. 11, 2010 Lefebvre US 2011/0036068 A1 Feb. 17, 2011 Hauswald DE 10 2010 044 483 A1 Mar. 8, 2012 Appeal 2020-000799 Application 14/287,125 3 REJECTIONS Claims 1, 3, 6–10, and 13 are rejected under 35 U.S.C. § 103 as being unpatentable over Lefebvre and Ramm. Claims 5 and 12 are rejected under 35 U.S.C. § 103 as being unpatentable over Lefebvre, Ramm, and Hauswald. OPINION Appellant argues claims 1, 3, 6–10, and 13 as a group. Appeal Br. 7– 13.2 We select claim 1 as representative. Claims 3, 6–10, and 13 stand or fall with claim 1. See 37 C.F.R. § 41.37(c)(1)(iv). Appellant also relies on the arguments presented with respect to claim 1 for the patentability of claims 5 and 12. Appeal Br. 13–14. The Examiner finds that Lefebvre teaches each limitation of claim 1, including “a plurality of deswirling struts (54),” but “does not teach the details of the deswirling struts” (i.e. “the deswirling struts [being] cambered in a direction of an incoming swirling flow of the exhaust gases such that a concave side of the cambered profile faces the incoming swirling flow”). Final Act. 3. The Examiner finds that “Ramm teaches . . . deswirling struts (7) [that] have a cambered profile . . . in a direction of an incoming swirling flow of the exhaust gases . . . such that a concave side of the cambered profile faces the incoming swirling flow.” Id. Appellant does not dispute these findings. The Examiner reasons that “[i]t would have been obvious . . . to modify Lefebvre to include the cambered profile of the struts as taught by 2 For simplicity, we cite only to Appellant’s arguments in the Appeal Brief, as the contentions presented in the Reply Brief are reiterations of those from the Appeal Brief. Appeal 2020-000799 Application 14/287,125 4 Ramm in order to deflect the hot gas in the axial direction so that the hot gas is as non-rotational as possible (Paragraph 0018).” Final Act. 4. Appellant responds that: (1) Lefebvre teaches away from the proposed combination (id. at 7–10); (2) the proposed combination would not have yielded predictable results (id. at 10–13); and (3) the proposed combination is based on conclusory statements (id. at 13). Appellant contends that “the purpose of the struts of Lefebvre and those of Ramm are very different” because “Lefebvre aims at minimizing the impact the struts have on the flow circulating therearound whereas Ramm aims at imparting a force on said flow.” Appeal Br. 8. Specifically, Appellant contends that “the struts of Lefebvre modified as suggested by the Office in view of Ramm will create more obstruction on the incoming flow and will impart a force on said incoming flow,” which “Lefebvre[ teaches] would unfavorably increase turbulence and back pressure.” Id. at 9. Appellant is correct that Lefebvre teaches its “struts 54 hav[ing] a generally aerodynamic profile for limiting any obstruction of the high velocity flows passing through the main gas path 26.” Lefebvre ¶ 25. As the Examiner notes, however, Lefebvre explains that its embodiments are merely exemplary, and various aerodynamic strut profiles can be used. Ans. 4; Lefebvre ¶ 25 (“The specific mixer strut aerodynamic profile shown in FIG. 7 is exemplary only.” (emphasis added)). Appellant responds that “even if a person skilled in the art were to use a different profile . . . , this person would never opt for a profile that would display a greater transversal width” or “for a profile that would impart a force on the incoming flow.” Appeal Br. 9. Appellant’s contention is not persuasive. Appeal 2020-000799 Application 14/287,125 5 We fail to see a teaching in Lefebvre that discourages the use of the proposed modification. See In re Fulton, 391 F.3d 1195, 1201 (Fed. Cir. 2004) (A teaching away requires “criticiz[ing], discredit[ing], or otherwise discourag[ing] the solution claimed.”). Rather than being discouraged from the proposed modification, one skilled in the art would have appreciated the trade-offs between mixing and obstructions to flow, as expressly taught by Ramm. See, e.g., Ramm ¶ 4 (“As the degree of mixing increases, the flow losses also increase as a rule. A good mixer therefore represents a compromise between these two effects.”). Appellant’s contentions regarding the alleged lack of predictable results are similarly unpersuasive. Appellant contends that “there are many differences between the mixers of Lefebvre and of Ramm” and “stresses here that designing a mixer is a complicated and cumbersome task.” Appeal Br. 11. Appellant’s contentions, however, amount to no more than unsupported allegations, which do not apprise us of error. Appellant references a declaration by one of the named inventors, Mark Huzzard Cunningham, submitted in a related application (15/673,047) (“the Cunningham Declaration”). Id. at 12. The Cunningham Declaration was filed in the related proceeding after this appeal, and is not in the record in this proceeding. We do not consider the Cunningham Declaration in this appeal. See 37 C.F.R. § 41.33(d)(2) (explaining that evidence filed after appeal will not be admitted, except for certain circumstances).3 Moreover, even if that declaration was properly before us, it would not be persuasive of Examiner error because of the internal inconsistencies 3 As noted above, the Cunningham Declaration was never filed in this proceeding. Appeal 2020-000799 Application 14/287,125 6 therein and the lack of any evidence supporting the statements therein relied on by Appellant. For example, Dr. Cunningham summarily concludes, without supporting evidence or meaningful explanation, that “it is clear to me that the struts 54 [in Lefebvre] are not configured to remove a circumferential component of the flow exiting the turbine section of the gas turbine engine” and “[t]hey are simply not long enough in term of their chord length to exert a force on the surrounding flow that would act to change a circumferential component of the flow circulating around them.” Cunningham Declaration ¶ 7. Dr. Cunningham similarly concludes that he is “positive that if the struts 54 were able to change a circumferential component of the flow circulating around them––by changing an angle of attack or with a cambered aerodynamic profile for instance––they would impart turbulence to the flow around them and, hence, they would clearly generate vibrations.” Id. ¶ 8. Dr. Cunningham then testifies that “due to the complexity of the flow circulating through those mixers, their real-life performances are very difficult to predict, even with currant tools such as computational fluid dynamics.” Id. ¶ 13. Accordingly, in view of these internal inconsistencies and lack of supporting evidence, Dr. Cunningham’s testimony would receive little weight, even if properly before us. Appellant’s contention that the rejection is based on conclusory statements is baseless. As noted above, the Examiner cites Ramm’s express disclosure to support the reason for the proposed modification to Lefebvre’s teachings. Final Act. 4 (citing Ramm ¶ 18). Indeed, consistent with the Examiner’s explanation, Ramm expressly states that “[t]he hot gas exiting from the rearmost guide blade ring 4 with rotation . . . is deflected in the Appeal 2020-000799 Application 14/287,125 7 axial direction by the profiled and curved . . . struts 7 of the guide ring and is therefore as non-rotational as possible.” Ramm ¶ 18. For at least the reasons set forth above, we are not apprised of Examiner error. CONCLUSION The Examiner’s rejections are affirmed. DECISION SUMMARY In summary: Claims Rejected 35 U.S.C. § Reference(s)/Basis Affirmed Reversed 1, 3, 6–10, 13 103 Lefebvre, Ramm 1, 3, 6–10, 13 5, 12 103 Lefebvre, Ramm, Hauswald 5, 12 Overall Outcome 1, 3, 5–10, 12, 13 TIME PERIOD FOR RESPONSE No time period for taking any subsequent action in connection with this appeal may be extended under 37 C.F.R. § 1.136(a). See 37 C.F.R. § 1.136(a)(1)(iv). AFFIRMED