United Technologies Corporation

Patent Trials and Appeals BoardApr 26, 2021

2020002303 (P.T.A.B. Apr. 26, 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. 15/266,855 09/15/2016 Scott D. Lewis 67097-3435PUS1;94716US01 4214 54549 7590 04/26/2021 CARLSON, GASKEY & OLDS/PRATT & WHITNEY 400 West Maple Road Suite 350 Birmingham, MI 48009 EXAMINER DELRUE, BRIAN CHRISTOPHER ART UNIT PAPER NUMBER 3745 NOTIFICATION DATE DELIVERY MODE 04/26/2021 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): ptodocket@cgolaw.com PTOL-90A (Rev. 04/07) UNITED STATES PATENT AND TRADEMARK OFFICE ____________ BEFORE THE PATENT TRIAL AND APPEAL BOARD ____________ Ex parte SCOTT D. LEWIS, DOMINIC J. MONGILLO, and ATUL KOHLI Appeal 2020-002303 Application 15/266,855 Technology Center 3700 ____________ Before JOSEPH A. FISCHETTI, KENNETH G. SCHOPFER, and AMEE A. SHAH, Administrative Patent Judges. SCHOPFER, Administrative Patent Judge. DECISION ON APPEAL Pursuant to 35 U.S.C. § 134(a), Appellant1 appeals from the Examiner’s decision to reject claims 1–20. We have jurisdiction under 35 U.S.C. § 6(b). We AFFIRM IN PART. 1 We use the word “Appellant” to refer to “applicant” as defined in 37 C.F.R. § 1.42. Appellant identifies the real party in interest as United Technologies Corporation. Appeal Br. 1. Appellant subsequently indicated that “United Technologies Corporation, has changed its name to Raytheon Technologies Corporation.” See Update To Real Party In Interest, filed Apr. 23, 2020. Appeal 2020-002303 Application 15/266,855 2 BACKGROUND The Specification states that “the disclosure relates to a cooling configuration in a stagnation zone of, for example, a turbine section airfoil.” Spec. ¶ 1. CLAIMS Claims 1 and 17 are the independent claims on appeal and recite: 1. An airfoil for a gas turbine engine comprising: pressure and suction side walls joined to one another at leading and trailing edges to provide an exterior airfoil surface, the pressure and suction side walls spaced apart from one another in a thickness direction, a stagnation line located near the leading edge, a cooling passage provided between the pressure and suction side walls, and showerhead cooling holes arranged at least one of adjacent to or on the stagnation line, at least one of the showerhead cooling holes has a metering hole fluidly connecting the cooling passage to a diffuser arranged at the exterior airfoil surface, wherein at least one showerhead cooling hole is arranged on each of opposing sides of the stagnation line, wherein each of the at least one showerhead cooling holes has the diffuser with a first diffuser angle that expands downstream in the thickness direction in opposing directions from one another when separated by the stagnation line, wherein the airfoil has a Zweifel lift coefficient of greater than 1.1, and the stagnation line shifts from the leading edge to the pressure side wall in the 60% span to the 95% span region on the pressure side wall aft of the leading edge. 17. An airfoil for a gas turbine engine comprising: pressure and suction side walls joined to one another at leading and trailing edges to provide an exterior airfoil surface, the pressure and suction side walls spaced apart from one another in a thickness direction, a stagnation line located near the leading edge, a cooling passage provided between the pressure and suction side walls, and showerhead cooling holes arranged at least one of adjacent to or on the stagnation line, at least one of the showerhead cooling holes has a metering hole fluidly Appeal 2020-002303 Application 15/266,855 3 connecting the cooling passage to a diffuser arranged at the exterior airfoil surface, the diffuser has a first diffuser angle that is from a centerline of the metering hole and expands downstream in the thickness direction, a second diffuser angle that is from the centerline and expands in a radially outward direction, a third diffuser angle that is 5°–20° from the centerline and expands in a radially inward direction, and a single metering hole is configured to feed the diffuser with a cooling fluid, wherein the airfoil has a Zweifel lift coefficient of greater than 1.1, and the stagnation line shifts from the leading edge to the pressure side wall in the 60% span to the 95% span region on the pressure side wall aft of the leading edge. Appeal Br. 9, 11. REJECTION2 The Examiner rejects claims 1–20 under 35 U.S.C. § 103 as unpatentable over Quach3 in view of Abdel-Messeh.4 DISCUSSION Claim 1–16 and 19 With respect to claim 1, the Examiner finds that Quach discloses an airfoil as claimed except that Quach does not disclose any showerhead cooling holes with “a metering hole fluidly connecting the cooling passage to a diffuser arranged at the exterior airfoil surface” or showerhead cooling holes with “the diffuser with a first diffuser angle that expands downstream in the thickness direction in opposing directions from one another when separated by the stagnation line.” Final Act. 5–6. With respect to these 2 A rejection of claim 13 under 35 U.S.C. § 112(b) has been withdrawn. See Adv. Act. 1, mailed Aug. 8, 2019. 3 Quach et al., WO 2014/137686 A1, pub. Sept. 12, 2014. 4 Abdel-Messeh et al., WO 98/19049, pub. May 7, 1998. Appeal 2020-002303 Application 15/266,855 4 claim limitations, the Examiner relies on Abdel-Messeh. Id. at 6–7. Specifically, the Examiner finds that Abdel-Messeh teaches: at least one of the showerhead cooling holes (26) has a metering hole (28) fluidly connecting the cooling passage (90) to a diffuser (30a) arranged at the exterior airfoil surface, (FIGS. 1-7; by way of example Page 7, lines 0-10) wherein each of the at least one showerhead cooling holes (26) has the diffuser (30a) with a first diffuser angle (m) that expands downstream in the thickness direction in opposing directions from one another when separated by the stagnation line (92). (as best seen in FIG. 3; Page 8. lines 5-27). Id. The Examiner then determines that it would have been obvious to “modify the showerhead cooling holes of Quach, with the diffuser cooling holes of Abdel-Messeh, since Abdel-Messeh teaches the formation of the diffusers enhances film cooling on the airfoil at all conceivable coolant air flow rates. ([S]ee Abdel-Messeh Page 5, lines 0-15).” Id. at 7. We agree with and adopt the Examiner’s findings with respect to claim 1. See Final Act. 5–7; see also Ans. 3–5. We are not persuaded of error by Appellant’s argument. Appellant argues that the Examiner cannot properly rely on Abdel- Messeh as teaching showerhead cooling holes with a diffuser having a first diffuser angle that expands downstream in the thickness direction in opposing directions from one another when separated by the stagnation line. Appeal Br. 4–5. More specifically, Appellant asserts that Abdel-Messeh does not disclose the location of the stagnation line and only references a “stagnation point in leading edge area.” Id. Appellant continues that Abdel- Messeh identifies area 24 as the leading edge area and in Figure 6 only shows diffusers arranged in the same direction in this area. Id. at 5. Appeal 2020-002303 Application 15/266,855 5 We are not persuaded of error by this argument. The Examiner finds that Abdel-Messeh teaches where the stagnation line is on leading edge area 24 by showing the flow path represented by arrows 27. Ans. 3. The Examiner defines the stagnation point based on the dictionary as either “a point on the surface of a solid body immersed in a fluid stream which directly faces the stream and at which the stream lines separate” or “a point near the leading edge or nose of a body placed in an airstream at which the airflow divides to go on either side of the body.” Id. at 4. Given either of these definitions, which Appellant does not dispute, we agree with the Examiner that one of ordinary skill in the art would readily understand that the stagnation point in Abdel-Messeh is effectively indicated by the arrow 24 that abuts area 24 orthogonally. Abdel-Messeh clearly indicates that the flowpath above this point on area 24 goes toward the suction side of the airfoil and the flowpath below this point on area 24 goes toward the pressure side of the airfoil. See Abdel-Messeh Fig. 3; 6, ll. 24–27 (explaining that the flow path is represented by arrows 27 and that the “leading edge axis LE extends radially through the stagnation point”). With respect to Appellant’s reference to Figure 6, we agree with the Examiner that Abdel-Messeh explains that this is a schematic depiction of a pattern of holes on the same side of the lead edge axis. Ans. 3; see Abdel-Messeh 7, ll. 2–4. In the Reply Brief, Appellant reiterates this argument and further asserts that Abdel-Messeh’s Figure 3a contradicts Figure 3 because it only shows one hole and does not illustrate holes in opposing directions. Reply Br. 2. Appellant asserts that Figure 3a shows the leading edge axis and “is the only figure that could arguably be used for determining the stagnation point.” Id. Thus, Appellant explains, “it is clear to a skilled worker that Appeal 2020-002303 Application 15/266,855 6 [Abdel-Messeh’s] figures are highly schematic in nature. A stagnation line cannot be inferred from [Abdel-Messeh’]s figures.” Id. at 3. We disagree. Appellant’s reference to Figure 3a does not persuade us of any error in the analysis presented above, and we do not find the figures to be contradictory. Rather, one of ordinary skill would understand that Figure 3a and Figure 6 are schematic in nature. Abdel-Messeh specifically states that this is the case. See Abdel-Messeh 5, l. 28; 6, ll. 5–6. In contrast, Figure 3 is described as “a horizontal fragmentary cross-section taken along line 3-3 of Fig. 2.” Id. at 5, ll. 26–27. Given these descriptions of the drawings, we agree with the Examiner, as discussed above, that one of ordinary skill in the art would recognize where the stagnation point is in Figure 3 of Abdel- Messeh and would further recognize that the passages 26 on either side of the stagnation point expand in opposing directions as required by the claim. To the extent Figure 3a only shows one hole, one of ordinary skill in the art would understand that it schematically depicts one of the holes on the pressure side of the airfoil depicted in Figure 3. Based on the foregoing, we are not persuaded of reversible error in the rejection of claim 1. Accordingly, we sustain the rejection of claim 1. Because Appellant does not present separate arguments with respect to the dependent claims, we also sustain the rejections of claims 2–16 and 19 for the same reasons. Claims 17, 18, and 20 We are persuaded of reversible error with respect to the Examiner’s determination regarding the third diffuser angle required by independent claim 17. Appeal 2020-002303 Application 15/266,855 7 With respect to claim 17, the Examiner acknowledges that neither Quach nor Abdel-Messeh teaches a third diffuser angle that is 5°–20° from the centerline and expands in a radially inward direction. Final Act. 14–15. However, the Examiner determines that it would have been obvious to combine Quach and Abdel-Messeh and to further provide a third diffuser angle as claimed “with the expected result of affecting or avoiding the film cooling separation on the leading edge of the blade.” Id. at 15 (citing Abdel 5, ll. 5–6). The Examiner further relies on Abdel-Messeh as teaching, “[i]t has been found that the shape of the outlet and diffuser area increases the film coverage of each passage such that ultimately fewer film coolant passages are required to cover a given airfoil span.” Abdel-Messeh 5, ll. 9– 11. The Examiner concludes that “the selection of the third diffuser angle could be undertaken following the extension of the same logic as taught by [Abdel-Messeh], under the same known conditions, and using the same result effective variables.” Final Act. 15–16. We agree with Appellant that the Examiner has not adequately established that the third diffuser angle is a result effective variable such that the discovery of an optimum value for the third diffuser angle would have been obvious. In particular, we determine that the Examiner does not sufficiently explain why the third diffuser angle would have been recognized as a result-effective variable. See In re Antonie, 559 F.2d 618, 620 (CCPA 1977). The Examiner relies on Abdel-Messeh’s statements that “the particular shape of the partial conical diffuser area avoids separation of the flow at the outlet” and “the shape of the outlet and diffuser area increases the film coverage of each passage such that ultimately fewer film coolant Appeal 2020-002303 Application 15/266,855 8 passages are required to cover a given airfoil span.” Final Act. 15. However, although Abdel-Messeh teaches that the shape of the conical diffuser affects the flow at the outlet and may be altered to increase film coverage, the Examiner does not provide evidence or explanation showing that the particular property claimed, i.e. the third diffuser angle, would have been recognized as a result effective variable in determining an appropriate shape for the diffusers in Abdel-Messeh. More specifically, the Examiner does not explain where the third diffuser angle is disclosed in Abdel-Messeh and does not explain why one of ordinary skill in the art would have recognized that such an angle is result effective based on Abdel-Messeh’s disclosure. In the Answer, the Examiner further explains that one of ordinary skill in the art is a person of ordinary creativity, would fit the patents together like pieces of a puzzle, and that such a person of ordinary skill in the art “need only look to [Abdel-Messeh] for all of the puzzle pieces.” Ans. 6. This statement seems to exemplify the Examiner’s error because the Examiner has not provided evidence or explanation showing that Abdel-Messeh provides “all of the puzzle pieces” as the Examiner asserts. Again, the Examiner fails to provide any evidence of a third diffuser angle in Abdel- Messeh or adequate explanation regarding how a person of ordinary skill in the art would have recognized that the third diffuser angle, as claimed, is a result effective variable. Thus, we agree with Appellant that the Examiner has not established that one of ordinary skill in the art would have recognized the third diffuser angle as a result effective variable. Based on the foregoing, we are persuaded of error in the rejection of independent claim 17. For the same reasons, we are persuaded of error in Appeal 2020-002303 Application 15/266,855 9 the rejection of dependent claims 18 and 20. Accordingly, we do not sustain the rejection of claims 17, 18, and 20. CONCLUSION We AFFIRM the rejection of claims 1–16 and 19. We REVERSE the rejection of claims 17, 18, and 20. In summary: Claims Rejected 35 U.S.C. § Reference(s)/Basis Affirmed Reversed 1–20 103 Quach, Abdel- Messeh 1–16, 19 17, 18, 20 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)(l)(iv). AFFIRMED IN PART