United Technologies CorporationDownload PDFPatent Trials and Appeals BoardJun 14, 20212020006053 (P.T.A.B. Jun. 14, 2021) Copy Citation 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. 15/673,635 08/10/2017 Gary D. Roberge 98415US01; 67097-3656PUS1 1537 54549 7590 06/14/2021 CARLSON, GASKEY & OLDS/PRATT & WHITNEY 400 West Maple Road Suite 350 Birmingham, MI 48009 EXAMINER BEEBE, JOSHUA R ART UNIT PAPER NUMBER 3745 NOTIFICATION DATE DELIVERY MODE 06/14/2021 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 GARY D. ROBERGE Appeal 2020-006053 Application 15/673,635 Technology Center 3700 ____________ Before NINA L. MEDLOCK, KENNETH G. SCHOPFER, and TARA L. HUTCHINGS, 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 1–20.2 We have jurisdiction under 35 U.S.C. § 6(b). We REVERSE. 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 Raytheon Technologies Corporation. Appeal Br. 1. 2 The Examiner has indicated that claims 21–24 recite allowable subject matter. Final Act. 19. Appeal 2020-006053 Application 15/673,635 2 BACKGROUND The Specification states that the “disclosure relates to a fan stage for gas turbine engines, and more particularly to rotating airfoils that include a tip pocket.” Spec. ¶ 2. CLAIMS Claims 1, 11, and 16 are the independent claims on appeal. Claim 1 is illustrative of the appealed claims and recites: 1. A fan blade for a gas turbine engine comprising: an airfoil section including a pressure sidewall and a suction sidewall that meet together at both a leading edge and a trailing edge, and extending radially between a root portion and a tip portion; and a tip pocket defined by collapsible external walls of the tip portion, and having a pocket opening at a radially outer face of the tip portion. Appeal Br. 10. REJECTIONS 1. The Examiner rejects claims 1–3, 16, and 17 under 35 U.S.C. § 103 as unpatentable over Densmore3 in view of Gibson.4 2. The Examiner rejects claims 4 and 5 under 35 U.S.C. § 103 as unpatentable over Densmore in view of Gibson and Krishnababu.5 3. The Examiner rejects claims 6–8 and 19 under 35 U.S.C. § 103 as unpatentable over Densmore in view of Gibson and Lim.6 3 Densmore, US 1,828,409, iss. Oct. 20, 1931. 4 Gibson, GB 1,107,024, pub. Mar. 20, 1968. 5 Krishnababu, US 2017/0102004 A1, pub. Apr. 13, 2017. 6 Lim, US 2013/0142651 A1, pub. June 6, 2013. Appeal 2020-006053 Application 15/673,635 3 4. The Examiner rejects claims 9 and 10 under 35 U.S.C. § 103 as unpatentable over Densmore in view of Gibson and Opper.7 5. The Examiner rejects claims 11–14 under 35 U.S.C. § 103 as unpatentable over Liston8 in view of Densmore and Gibson. 6. The Examiner rejects claim 15 under 35 U.S.C. § 103 as unpatentable over Liston in view of Densmore, Gibson, and Lim. 7. The Examiner rejects claim 18 under 35 U.S.C. § 103 as unpatentable over Densmore in view of Gibson and Smuland.9 8. The Examiner rejects claim 20 under 35 U.S.C. § 103 as unpatentable over Densmore in view of Gibson and Ochiai.10 DISCUSSION With respect to claim 1, the Examiner finds that Densmore teaches a blade for a turbine engine including an airfoil section as claimed and a collapsible external wall at a tip portion of the airfoil section. Final Act. 5–6 (citing Densmore Figs. 1, 2; page 1, ll. 78–95). The Examiner acknowledges that Densmore does not teach that the collapsible wall forms a tip pocket as required by the claim. Id. at 6. The Examiner relies on Gibson as disclosing “[r]adially outermost sealing element lip/lips(4) [that] can be very effective as pockets/sleeves” and that can be provided on the outside of a blade. Id. (citing Gibson Figs. 3, 4; page 2, ll. 7–13). The Examiner finds that Gibson teaches that the two sides of the pocket at the tip end “increase[] the resistance to fluid flow through the clearance space compared to a single 7 Opper, DE 10305351 A1, pub. Aug. 19, 2004. 8 Liston et al., US 5,259,724, iss. Nov. 9, 1993. 9 Smuland et al., US 3,220,697, iss. Nov. 30, 1965. 10 Ochiai et al., US 8,366,400 B2, iss. Feb. 5, 2013. Appeal 2020-006053 Application 15/673,635 4 element.” Id. (citing Gibson page 1, ll. 68–77). The Examiner also finds that Gibson is “concerned with clearances and unshrouded rotating blades . . . as well as the improvements of placing lips on both sides of the airfoil to form a pocket, [and] that these features can be formed on the blade at formation, removing the need for a filleted portion by using the sleeve to serve the function.” Id. (citing Gibson page 2, ll. 5–19). Based on the teachings of Gibson, the Examiner determines: It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the blade of [Densmore] such that the bending element of [Densmore] at the tip was formed all the way around the blade as a full pocket as taught by [Gibson] for the purpose of this element being more resistant to fluid flow through the clearance space. Further, per [Gibson], it would be desirable to apply the combined teachings to fan blades as well, as [Gibson] discloses unshrouded fan blades of the system have similar concerns with loss of flow over their ends as [Gibson] is concerned with and tip rubbing clearance damage as [Densmore] is concerned with, thus they would also benefit from improvements to longevity and performance as [Densmore] and [Gibson] teach. This would yield collapsible walls at the tip, forming a tip pocket at the radially outer face portion of fan blades. Final Act. 6–7. The Examiner relies on substantially the same findings and conclusion in relying on the combination of Densmore and Gibson to reject independent claims 11 and 16. See Final Act. 7–8, 14–15. We are persuaded of error by Appellant’s argument that the Examiner has not set forth an adequate reason to support the combination proposed. Obviousness is a legal conclusion involving a determination of underlying facts. Under § 103, the scope and content of the prior art are to be determined; differences between the prior art and the claims at issue are to be ascertained; and the level of ordinary skill in the Appeal 2020-006053 Application 15/673,635 5 pertinent art resolved. Against this background, the obviousness or nonobviousness of the subject matter is determined. Such secondary considerations as commercial success, long felt but unsolved needs, failure of others, etc., might be utilized to give light to the circumstances surrounding the origin of the subject matter sought to be patented. KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 406 (2007) (quoting Graham v. John Deere Co. of Kansas City, 383 U.S. 1, 17–18 (1966)). “[R]ejections 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.” Id. at 418 (alteration in original) (quoting In re Kahn, 441 F.3d 977, 988 (Fed. Cir. 2006)). Densmore discloses a blade for a turbine including “a blade portion 11, as usual, and a relatively thin, bendable extension 12.” Densmore 1, ll. 80–82. Densmore discloses that the bendable extension projects outwardly from the blade tip, “preferably as a continuation of a working surface,” and is inclined backwardly with respect to movement of the blade tip. Id. at 1, ll. 85–95. The extension provides “exceedingly small” radial clearance “and in the event any rubbing occurs, the point of contact will always follow the blade and hence, will cause the rubbed metal to flow in one direction and tend to prevent vibration when the rub takes place.” Id. at 2, ll. 1–14. With this design, Densmore discloses that rubbing will result in no serious consequences and that the extension may be trimmed to restore the original clearance if the extension is damaged. Id. Gibson discloses “a blade of a turbo-machine fitted at its free end with a sleeve having an outer profile similar to that of the blade.” Gibson 1, ll. 29–31. Gibson teaches that a blade with a tip having a reduced cross- Appeal 2020-006053 Application 15/673,635 6 sectional area that has been damaged by rubbing may be repaired by placing a sleeve at the free end of the blade, which provides the advantage of not having to replace the entire blade. Id. at 1, ll. 57–68. Alternatively, Gibson teaches that blades may be initially provided with such a sleeve such that there is no need for the blade to be formed with a reduced cross-sectional area. Id. at 2, ll. 8–13. Gibson also teaches that although the use of a sleeve increases the profile of the blade, “any loss of performance resulting [therefrom] . . . is offset by the fact that the presence of two walls of the sleeve adjacent the wall of the casing or the surface of the rotor, increases the resistance to fluid flow through the clearance space compared with the conventional construction.” Id. at 1, ll. 69–78. Appellant argues that the Examiner has not set forth an adequate motivation to combine the references. See Appeal Br. 3–7. We agree to the extent that we determine that the Examiner has not shown why one of ordinary skill in the art would have had a reason to make the combination proposed by the Examiner. The Examiner determines that it would have been obvious to extend Densmore’s collapsible portion around the entirety of the tip of Densmore’s blade to form a pocket as claimed based on Gibson’s teachings. See Final Act. 6–7. Yet the Examiner does not adequately explain how the teachings of Gibson would have led one of ordinary skill in the art to modify Densmore to extend Densmore’s collapsible wall around the entirety of the device, rather than providing a separate sleeve as taught by Gibson, or that doing so would provide any benefit to Densmore’s device. As noted above, Densmore teaches the use of a collapsible tip portion of a blade that provides for minimal clearance, reduced rubbing vibrations, Appeal 2020-006053 Application 15/673,635 7 and allows for trimming to restore the original clearance in the event that the collapsible tip is damaged. In contrast, Gibson teaches the use of a sleeve intended to be placed over the tip portion of a blade, either to repair a damaged tip portion or to replace a reduced cross-section portion of the blade. Gibson teaches only the use of a sleeve portion over the tip of a blade and does not suggest providing a pocket portion as an extension of the walls of the blade. The Examiner does not adequately explain why a person of ordinary skill in the art would have had a reason to modify Densmore as proposed in light of Gibson’s teaching of only the use of a sleeve addition to a blade. Rather, the combination would seem to only suggest the use of a sleeve, as taught by Gibson, around the tip of Densmore’s blade as a means of repairing the blade should Densmore’s tip portion be damaged beyond repair. Such a combination does not appear to result in a device as claimed, which is required to have a tip pocket made of collapsible portions of the external walls of the blade. Further, to the extent the Examiner finds that one of ordinary skill in the art would have made the modification proposed “for the purpose of this element being more resistant to fluid flow through the clearance space,” the Examiner can only speculate that such would be the case if Densmore’s collapsible wall were extended as proposed. The Examiner has not provided any evidence or explanation adequately showing that extending a collapsible wall as proposed would yield such a benefit. It is not readily apparent to us that extending Densmore’s collapsible wall would provide such an effect given that Densmore already discloses minimal clearance between the collapsible blade wall and the casing and given that Gibson teaches only that the sleeve may be formed of the same material as the blade, which seems to Appeal 2020-006053 Application 15/673,635 8 indicate that it is not collapsible. See Gibson 1, ll. 86–87. In short, it is not clear from the evidence provided how the proposed modification would affect the performance of Densmore’s blade. Based on the foregoing, we are persuaded of error in the rejection of independent claim 1. The Examiner relies on the same findings and reasoning with respect to the rejection of independent claim 16, and thus, we are persuaded of error in the rejection of claim 16 for the same reasons. With respect to the rejection of independent claim 11, the Examiner relies on the findings and reasoning discussed above and does not provide any further evidence or explanation with respect to the additional reference, Liston, that would cure the deficiency discussed above. Thus, we are also persuaded of error in the rejection of independent claim 11. With respect to the dependent claims, the Examiner does not provide any additional evidence or explanation that would cure the deficiency in the rejections of the independent claims. Thus, we are also persuaded of error in the rejections of the dependent claims. Accordingly, we do not sustain the rejections of claims 1–20. CONCLUSION We REVERSE the rejections of claims 1–20. In summary: Claim(s) Rejected 35 U.S.C. § Reference(s)/Basis Affirmed Reversed 1–3, 16, 17 103 Densmore, Gibson 1–3, 16, 17 4, 5 103 Densmore, Gibson, Krishnababu 4, 5 6–8, 19 103 Densmore, Gibson, Lim 6–8, 19 Appeal 2020-006053 Application 15/673,635 9 Claim(s) Rejected 35 U.S.C. § Reference(s)/Basis Affirmed Reversed 9, 10 103 Densmore, Gibson, Opper 9, 10 11–14 103 Liston, Densmore, Gibson 11–14 15 103 Liston, Densmore, Gibson, Lim 15 18 103 Densmore, Gibson, Smuland 18 20 103 Densmore, Gibson, Ochiai 20 Overall Outcome 1–20 REVERSED Copy with citationCopy as parenthetical citation