MTU Aero Engines AG

Patent Trials and Appeals BoardJun 7, 2021

2020006514 (P.T.A.B. Jun. 7, 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. 15/368,907 12/05/2016 Juergen KRAUS 6570-P50325 7072 13897 7590 06/07/2021 Abel Schillinger, LLP 12414 Alderbrook Drive Suite 201 Austin, TX 78758 EXAMINER MARIEN, ANDREW JAMES ART UNIT PAPER NUMBER 3745 NOTIFICATION DATE DELIVERY MODE 06/07/2021 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): hmuensterer@abel-ip.com mail@Abel-IP.com PTOL-90A (Rev. 04/07) UNITED STATES PATENT AND TRADEMARK OFFICE BEFORE THE PATENT TRIAL AND APPEAL BOARD Ex parte JUERGEN KRAUS, HERMANN KLINGELS, and MANFRED FELDMANN Appeal 2020-006514 Application 15/368,907 Technology Center 3700 Before MURRIEL E. CRAWFORD, MICHAEL L. WOODS, and MATTHEW S. MEYERS, Administrative Patent Judges. WOODS, 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, 4–18, and 21–24. 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 the real party in interest as MTU Aero Engines AG. Appeal Br. 3. Appeal 2020-006514 Application 15/368,907 2 CLAIMED SUBJECT MATTER The claims relate to “a blade or vane for a turbomachine such as a gas turbine.” Spec. 1:6–8. Claim 1, reproduced below, is illustrative of the claimed subject matter: 1. A turbine blade which comprises at least one cavity, wherein the at least one cavity is defined by a wall having one or more surface discontinuities which comprise at least one elevation, a maximum height of the at least one elevation being at least twice a wall thickness in an area immediately adjacent to the at least one elevation and/or the maximum height of the at least one elevation being at least twice a minimum wall thickness of the blade. REFERENCES The prior art relied upon by the Examiner is: Name Reference Date Samit US 6,048,174 Apr. 11, 2000 Deal US 2011/0211965 A1 Sept. 1, 2011 Blaney US 2016/0084089 A1 Mar. 24, 2016 Prentice US 2016/0115820 A1 Apr. 28, 2016 Theratil US 2017/0175776 A1 June 22, 2017 REJECTIONS Claim(s) Rejected 35 U.S.C. § References 1, 4–6, 8, 9, 15–17, 21–24 103 Samit, Theratil 7 103 Samit, Theratil, Prentice 10, 11, 18 103 Samit, Theratil, Blaney 12–14 103 Samit, Theratil, Deal Appeal 2020-006514 Application 15/368,907 3 OPINION Claims 1, 4–6, 8, 9, 15–17, and 21–23 The Examiner finds that Samit discloses a turbine blade, with cavity defined by a wall, having surface discontinuities that comprise an elevation, but is “silent” as to the two “maximum height” requirements. Final Act. 4. To address the maximum height requirement, the Examiner relies on Theratil, and asserts that “Theratil teaches that the thickness of frequency modifiers affect the distribution of natural vibration frequency.” Id. at 5. The Examiner elaborates that “Theratil discloses different areas in the blade that have different thickness due to high strain energy and low strain energy. This creates a thickness that is more than the other which would be creating an elevation.” Ans. 4. Appellant contends that the Examiner’s reliance on Theratil falls short, arguing that Theratil does not mention “any elevations, let alone the (maximum) height of elevations (peak height) in relation to the airfoil thickness.” Appeal Br. 8; see also Reply Br. 3 (“THERATIL does not even disclose the recitations of the instant claims which are missing from the disclosure of SAMIT”) (emphasis omitted). Appellant’s argument is persuasive. The Examiner has not sufficiently established that Theratil’s disclosure of varying the exterior surface of a solid blade would have led a skilled artisan to vary the maximum height limitations on the interior surface of a wall that defines a cavity, as claimed. Theratil discloses introducing thickness variations on solid airfoil blades, which have no cavity. See Theratil ¶ 4 (“different first and second airfoil thickness distributions”); see also id. ¶ 37 (“Airfoil ‘thickness’ as Appeal 2020-006514 Application 15/368,907 4 used [in Theratil] is the material thickness between the pressure and suction side surfaces of the airfoil of the blade”). Theratil’s blades are solid blades—without any cavity or hollow interior—and the variation in thickness is accomplished by adding or removing material to or from the exterior surface of the blade. Id. ¶ 49. Thus, Theratil does not disclose elevations on the surface of a wall that defines a cavity—that is, on the interior surface of a blade—since Theratil has no interior surface. Moreover, the Examiner does not articulate any reason to modify Samit’s wall thickness based on Theratil’s teachings. In proposing to modify Samit, the Examiner reasons: It is obvious to one of ordinary skill in the art before the effective filling date of the claimed invention to have the a maximum height of the at least one elevation being at least twice a wall thickness in an area immediately adjacent to the at least one elevation and/or the maximum height of the at least one elevation being at least twice a minimum wall thickness of the blade. Appeal Br. 5 (emphasis omitted). This statement merely asserts that both of the “maximum height” limitations are obvious, without evidence or explanation. The Examiner’s reasoning falls short of that required under KSR. KSR International Co. v. Teleflex Inc., 550 U.S. 398 (2007). In KSR, the Court in noted that the analysis supporting a rejection under 35 U.S.C. § 103 should be made explicit. Id. at 418. The Federal Circuit further stated that “rejections on obviousness grounds cannot be sustained by mere conclusory statements; instead, there must be some articulated reasoning with some rational underpinning to support the legal conclusion of obviousness.” In re Kahn, 441 F.3d 977, 988 (Fed. Cir. 2006), cited with approval in KSR, 550 U.S. at 418. Appeal 2020-006514 Application 15/368,907 5 Here, in addressing the “maximum height” limitations, the rejection fails to sufficiently articulate a reason to modify Samit based on Theratil’s teachings. See Final Act. 5. For these reasons, we do not sustain the rejection of claim 1, or of the rejection to dependent claims 4–6, 8, 9, 15–17, and 21–23, which inherit the same flawed analysis. See Final Act. 4–9. Claim 24 Independent claim 24 recites, “A turbine blade which comprises at least one cavity, wherein the at least one cavity is defined by a wall having one or more surface discontinuities which comprise at least one depression.” The Examiner finds Samit alone discloses the blade as claimed, citing Samit’s Figure 4, and specifically the “Depression between buttress[] (82) and taper (80).” Final Act. 9. Appellant argues, “the Examiner's interpretation of the (wide) area between the buttresses 82 and the taper 80 in Fig. 4 of SAMIT as a single depression . . . is unreasonably broad. Merely because an area is located between two ‘elevations’ does not automatically qualify this area as a ‘depression’.” Appeal Br. 15. We agree with Appellant. The Specification does not define the term “depression,” it merely states that depressions are one type of surface discontinuity that can be selected. See Spec. 2:13–15; see also id. at 3:24–28, 4:4–9. The ordinary and customary meaning of “depression,” which an ordinary artisan would associate with Appellant’s claimed invention, is “a place or part that is lower than the surrounding area.” Merriam-Webster Online Dictionary (last Appeal 2020-006514 Application 15/368,907 6 retrieved on May 28, 2021, from https://www.merriam- webster.com/dictionary/depression). Samit shows an airfoil internal wall that is generally of a uniform thickness, except at the two extreme ends, where the wall thickness is greater in the location of buttress 82 and the increasing taper 80. See Samit, Fig. 4. An ordinary artisan would not recognize the “surrounding area,” that is essentially the entire wall in Samit, as being defined by the high points at each end. Instead, the “surrounding area” would be interpreted as the wall between the structures that result in the two high points. Because that area has no “place that is lower” than the surrounding wall area, we disagree with the Examiner’s finding that Samit discloses a “depression” located between buttress 82 and taper 80. See Final Act. 9. For this reason, we do not sustain the rejection of claim 24. Claims 7, 10–14, and 18 The Examiner has not established on the record that any of Prentice (claim 7), Blaney (claims 10, 11, 18), or Deal (claims 12–14) remedy the shortcomings in the rejection of claim 1. Therefore, we do not sustain the rejections of these claims. CONCLUSION The Examiner’s rejections are REVERSED. Appeal 2020-006514 Application 15/368,907 7 DECISION SUMMARY Claim(s) Rejected 35 U.S.C. § Reference(s)/Basis Affirmed Reversed 1, 4–6, 8, 9, 15–17, 21–24 103 Samit, Theratil 1, 4–6, 8, 9, 15–17, 21–24 7 103 Samit, Theratil, Prentice 7 10, 11, 18 103 Samit, Theratil, Blaney 10, 11, 18 12–14 103 Samit, Theratil, Deal 12–14 Overall Outcome 1, 4–18, 21– 24 REVERSED