United Technologies Corporation

Patent Trials and Appeals Board

Mar 1, 2022

2021003596 (P.T.A.B. Mar. 1, 2022)

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. 15/200,149 07/01/2016 Charles E. Lents 93564US01; 67097-3400PUS1 8606 54549 7590 03/01/2022 CARLSON, GASKEY & OLDS/PRATT & WHITNEY 400 West Maple Road Suite 350 Birmingham, MI 48009 EXAMINER THOMAS, KYLE ROBERT ART UNIT PAPER NUMBER 3741 NOTIFICATION DATE DELIVERY MODE 03/01/2022 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 CHARLES E. LENTS, LARRY W. HARDIN, JONATHAN RHEAUME, and JOSEPH B. STAUBACH Appeal 2021-003596 Application 15/200,149 Technology Center 3700 Before JENNIFER D. BAHR, DANIEL S. SONG, and CHARLES N. GREENHUT, Administrative Patent Judges. SONG, Administrative Patent Judge. DECISION ON APPEAL STATEMENT OF THE CASE Pursuant to 35 U.S.C. § 134(a), the Appellant1 appeals from the Examiner’s decision to reject claims 1-9, 11, and 20. Claims 10 and 12-19 have been canceled. 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(a). The Appellant identifies the real party in interest as Raytheon Technologies Corporation. Appeal Br. 1. Appeal 2021-003596 Application 15/200,149 2 CLAIMED SUBJECT MATTER The claims are directed to an aircraft parallel hybrid gas turbine electric propulsion system. Claim 1, reproduced below, is illustrative of the claimed subject matter: 1. An aircraft including a gas turbine engine comprising: a core including a compressor section having a first compressor and a second compressor, a turbine section having a first turbine and a second turbine, and a primary flowpath fluidly connecting the compressor section and the turbine section; the first compressor is connected to the first turbine via a first shaft; the second compressor is connected to the second turbine via a second shaft; a motor connected to the first shaft such that rotational energy generated by the motor is translated to the first shaft; wherein the gas turbine engine includes a takeoff mode of operation, a top of climb mode of operation, and at least one additional mode of operation; a controller configured to control the mode of operation of the gas turbine engine; and wherein the at least one additional mode of operation includes a cruise mode of operation and a geometry of the gas turbine engine is physically sized such that a turbine inlet temperature of the second turbine is at a maximum temperature for the top of climb mode of operations while said engine is in said cruise mode of operation, and wherein the maximum turbine inlet temperature corresponds to a maximum thrust output of the core and the maximum thrust output of the core is less than an aircraft thrust requirement on the gas turbine engine in at least one of the takeoff mode of operations and the top of climb mode of operations. Appeal Br. 8 (Claims App., emphasis added).2 2 We note that under the heading “Related Appeals and Interferences” of the Appeal Brief, the Appellant states it is “unaware of any appeals or Appeal 2021-003596 Application 15/200,149 3 REFERENCES The prior art relied upon by the Examiner is: Name Reference Date McCombs US 4,517,796 May 21, 1985 Michalko US 2006/0174629 A1 Aug. 10, 2006 Fukuda US 2009/0113896 A1 May 7, 2009 Hoffjann US 2009/0293494 A1 Dec. 3, 2009 Moniz US 7,997,085 B2 Aug. 16, 2011 Kupratis US 2013/0192200 A1 Aug. 1, 2013 Webster US 2014/0145008 A1 May 29, 2014 Anghel US 2014/0245748 A1 Sept. 4, 2014 Gulen US 2014/0331686 A1 Nov. 13, 2014 Krug US 2015/0151847 A1 June 4, 2015 REJECTIONS3 1. Claims 1 and 9-11 are provisionally rejected on the ground of nonstatutory double patenting. Final Act. 3. The Examiner also rejects various claims under 35 U.S.C. § 103 as follows: interferences which may be related to, directly affect or be directly affected by or have a bearing on the Board’s decision in the pending appeal.” Appeal Br. 1. However, Appeal 2020-004370 (decided April 2, 2021) appears to be pertinent to the issues presented in this appeal. See 37 C.F.R. § 41.37(c)(1)(ii). In that regard, the Examiner may want to consider the prior art and the Board’s decision in Appeal 2020-004370 in any further prosecution of the present application. In addition, the Appellant, and its attorney (who are involved in the present appeal as well as in Appeal 2020- 004370), are reminded of their duty of candor in proceedings before the Office. 37 C.F.R. § 1.56 (“Each individual associated with the filing and prosecution of a patent application has a duty of candor and good faith in dealing with the Office . . . .”). 3 The Examiners rejection of claims 1-9, 11, and 20 under 35 U.S.C. § 112(b) for being indefinite has been withdrawn. Ans. 33; Final Act. 9. Appeal 2021-003596 Application 15/200,149 4 2. Claims 1 and 2 as being unpatentable over Anghel in view of Gulen and McCombs. Final Act. 11. 3. Claims 3, 4, and 6 as being unpatentable over Anghel in view of Gulen, McCombs, and Krug. Final Act. 16. 4. Claim 7 as being unpatentable over Anghel in view of Gulen, McCombs, Krug, and Hoffjann. Final Act. 19. 5. Claim 8 as being unpatentable over Anghel in view of Gulen, McCombs, and Hoffjann. Final Act. 20. 6. Claim 11 as being unpatentable over Anghel in view of Gulen, McCombs, and Fukuda. Final Act. 21. 7. Claims 1 and 2 as being unpatentable over Moniz in view of Anghel, Gulen, and McCombs. Final Act. 23. 8. Claim 5 as being unpatentable over Moniz in view of Anghel, Gulen, McCombs, Michalko, and Kupratis. Final Act. 28. 9. Claim 9 as being unpatentable over Moniz in view of Anghel, Gulen, McCombs, and Kupratis. Final Act. 30. 10. Claim 20 as being unpatentable over Anghel in view of Gulen, Fukuda, and McCombs. Final Act. 31. OPINION The Examiner rejects all of the claims as being unpatentable over the prior art of record. Each of these rejections rely on teachings of the prior art references Anghel, Gulen, and McCombs. The Appellant disputes the Examiner’s understanding of Anghel, and argues that the rejections based thereon are improper. We address the prior art rejection first. Appeal 2021-003596 Application 15/200,149 5 Rejections 2-6: Claims 1-4, 6-8, and 11 As to independent claim 1, the Examiner finds that Anghel discloses a gas turbine engine for an aircraft substantially as claimed, including the limitation that “the maximum thrust output of the core is less than an aircraft thrust requirement on the gas turbine engine in at least one of the takeoff mode of operations and the top of climb mode of operations.” Final Act. 12-13. This finding is based on the disclosure in Anghel regarding providing power from the motor/generator to augment the gas turbine engine when the engine is operating in a “sub-optimal” condition, for example, during take-off, in further view of various teachings in Gulen and McCombs. Final Act. 12-13 (citing Anghel ¶¶ 3, 21, 29). In that regard, the Examiner states that it is well known in the art to configure/size the gas turbine engine to operate with peak efficiency during cruise; further the engine is sub-optimal/undersized, where it is not delivering the commanded/required thrust, for operating modes other than cruise, which includes takeoff and climb; therefore the engine is undersized relative to a thrust requirement for at least takeoff. Final Act. 12 (parentheses and bolding removed). As to the turbine inlet temperature limitation, the Examiner concludes that it would have been obvious to one of ordinary skill in the art to have such maximum temperature at the turbine inlet in order to operate at maximum efficiency as taught by Gulen. Final Act. 15. The bases and reasoning for the Examiner’s findings as to Anghel are more clearly set forth in the Answer as follows (enumerated for clarity): 1. Gulen teaches that “in order to operate the gas turbine at optimal/peak efficiency[,] one must consider the highest possible Appeal 2021-003596 Application 15/200,149 6 temperature of the gas turbine, which . . . is measured at the turbine inlet.” Ans. 34 (citing Gulen ¶ 5). 2. “[I]t is well known in the art of gas turbines that . . . in order to achieve optimum thermal efficiency this turbine inlet temperature is kept at the highest allowable temperature.” Ans. 34 (citing McCombs, col. 3, ll. 48-50). 3. “McCombs discusses . . . that the maximum thrust provided by the gas turbine engine occurs when the turbine inlet temperature is at its maximum allowable temperature, which also coincides with the gas turbine engine operating at optimum thermal efficiency.” Ans. 34 (citing McCombs, col. 3, ll. 48-50). 4. Thus, in view of teachings 1-3 above, a person of ordinary skill in the art would “recognize that when an aircraft gas turbine engine is operating at peak/optimum thermodynamic/thermal efficiency the gas turbine engine would also be operating with the turbine inlet temperature at its maximum temperature and the engine would be providing the maximum possible thrust.” Ans. 34-35. 5. Anghel discloses that “the aircraft engine is designed such that it is most efficient, and thus operate at peak/optimum efficiency, during ‘cruise’ operations and operate in a ‘sub-optimal condition’ during take-off, descent and other transient operations.” Ans. 35 (citing Anghel ¶¶ 3, 13). 6. “Anghel links the term sub-optimal with the engine not delivering the required/commanded thrust.” Ans. 35 (citing Anghel ¶ 29). Appeal 2021-003596 Application 15/200,149 7 7. Therefore, “the gas turbine engine of Ang[h]el provides maximum thrust during cruise and the gas turbine engine would not be able to provide the commanded thrust/thrust requirement necessary for take-off, descent and other transient operations, and thereby would be operating sub-optimally.” Ans. 35. 8. The conclusion above is evidenced by “the motor/generator [of Anghel being] operated to provide power to the shaft/increase thrust of the gas turbine engine.” Ans. 35 (citing Anghel ¶¶ 14, 29). The Appellant argues that the rejections are improper because the Examiner “is improperly relying on unsupported inferences and assumptions to leap the gap from operating sub-optimally to having a maximum thrust output that is less than the thrust requirement.” Appeal Br. 7. Specifically, the Appellant argues that the Examiner “improperly equates ‘sub optimal operations’ [disclosed in Anghel] with ‘the maximum thrust output of the core is less than a thrust requirement in at least one of the takeoff mode of operations and the top of climb mode of operations.’” Appeal Br. 4-5.4 According to the Appellant, “[t]here is no teaching within Anghel, or in any other reference that has been identified, that supports the [E]xaminer’s contention that operating sub-optimally (or inefficiently) means that the maximum possible thrust of the engine is less than the thrust required of the engine for that mode of operation,” and that the Examiner’s characterization 4 The Appeal Brief includes text with strike out line therethrough, indicating that such text is deleted. Thus, we do not consider such deleted text in consideration of this appeal. Appeal 2021-003596 Application 15/200,149 8 of Anghel “is not correct.” Appeal Br. 6. We generally agree with the Appellant. First, we disagree with the Examiner’s understanding of the term “sub-optimal” in Anghel. Anghel does disclose that “[w]hile gas turbine engines are optimized for cruise, during certain flight phases, such as take- off and descent . . . the engine may operate in a sub-optimal condition.” Anghel ¶ 3. The very next sentence explains that “sub-optimal” refers to reduced fuel efficiency by stating “[s]ub-optimal operation increases fuel burn, and therefore leads to an increased expense of operation.” Id.; see also id. ¶ 14 (“This novel configuration will (1) reduce the fuel burn during these off-optimum conditions . . . .”). Thus, Anghel teaches that even when optimized for cruise, the gas turbine engine operates sub-optimally in certain flight phases such as take-off, but teaches nothing about the gas turbine engine having a maximum thrust that is less than the aircraft thrust requirement during takeoff. As the Examiner correctly points out, Anghel does disclose augmenting the power available from the engine using the motor. Ans. 35; Anghel ¶¶ 14, 21, 29. In addition, Anghel further discloses that its engine control is “configured to determine when the engine is not delivering the commanded thrust or power or otherwise operating sub-optimally,” and in such operations, causes mechanical output power to be supplied by the motor/generator. Anghel ¶ 29. The Examiner surmises that this means that there is insufficient thrust during takeoff based on the earlier disclosure in Anghel regarding takeoff being a sub-optimal operation. However, as discussed above, “sub-optimal” refers to reduced fuel efficiency, and is not directly tied to the maximum thrust of the gas turbine engine being less than Appeal 2021-003596 Application 15/200,149 9 the aircraft thrust requirement during takeoff or top of climb modes of operations as inferred by the Examiner. Moreover, the mere fact that mechanical output power is supplied by the motor/generator in various operations, including takeoff, does not necessarily mean that the maximum thrust of the gas turbine engine is less than the aircraft thrust requirement during takeoff or top of climb modes of operations. Mechanical output power may be supplied by the motor/generator for whatever reason even when the maximum thrust of the gas turbine engine exceeds the aircraft thrust requirement during takeoff or top of climb modes of operations, for example, when the engine is “operating sub-optimally,” i.e., at reduced fuel efficiency. Use of such mechanical output power of the motor/generator during such phases of operation where the gas turbine engine is operating at reduced fuel efficiency would act to improve overall operational fuel efficiency by reducing reliance on the gas turbine engine when it is operating at reduced fuel efficiency. Indeed, such operation is what Anghel explicitly teaches. See Anghel ¶ 14 (“This novel configuration will (1) reduce the fuel burn during these off-optimum conditions . . . and (3) augment the power available from the engine.”). The Examiner responds by asserting that “Anghel links the term sub- optimal with the engine not delivering the required/commanded thrust.” Ans. 35 (citing Anghel ¶ 29). However, the relevant portion of Anghel actually states “when the engine is not delivering the commanded thrust.” Anghel ¶ 29. As the Appellant points out, the Examiner’s statement “is incorrect at least in part because the ‘required’ thrust and the ‘commanded’ thrust are not the same thing,” and Anghel is “describ[ing] a situation where Appeal 2021-003596 Application 15/200,149 10 the engine is producing less thrust than is commanded by the controller,” which “does not describe a situation where the maximum possible thrust of the engine is less than the thrust required in the [recited] mode of operations.” Reply Br. 5. Thus, we agree with the Appellant that the Examiner “improperly equates ‘sub optimal operations’ with ‘the maximum thrust output of the core is less than a thrust requirement in at least one of the takeoff mode of operations and the top of climb mode of operations.’” Appeal Br. 4-5; see also Reply Br. 5 (“[Anghel] provides no indication that the maximum thrust output of the engine in the sub-optimal modes is less than the required thrust. Rather it only establishes that the engine operates ‘sub-optimally’.”). The Examiner’s reasoning also relies on Anghel’s disclosure that “[t]ypically, gas turbine engines are configured so as to operate most efficiently during ‘cruise’ operations, that is, at engine speeds typically used during the cruise portion of the vehicle operation.” Anghel ¶ 3. Accordingly, the Examiner determines that Anghel’s engine “is designed such that it is most efficient, and thus operate at peak/optimum efficiency, during ‘cruise’ operations.” Ans. 35. As noted, the Examiner also relies on Gulen for its disclosure that “[a]n important parameter controlling the efficiency of a gas turbine combined cycle power plant is the maximum temperature of the gas turbine Brayton cycle,” and on McCombs for its disclosure that “[i]n order to obtain optimum thermal efficiency and maximum thrust, the turbine inlet temperature is maintained as close to the allowable limits as possible.” Gulen ¶ 5; McCombs, col. 3, ll. 48-50. Based on the additional disclosure in Gulen and McCombs, the Examiner determines that Appeal 2021-003596 Application 15/200,149 11 one of ordinary skill in the art would recognize that, without explicitly stating the exact claimed language, that the gas turbine engine, of Ang[h]el, operates with a maximum thermal efficiency, and thus with maximum thrust, during cruise thereby making the maximum thrust output of the engine less than the thrust requirement for at least take-off and other modes in which the gas turbine engine is operating sub-optimally. Ans. 36; see also Ans. 35 (“at least the mode of operation of take-off requires thrust higher than that of the cruise mode of operation and as stated above the maximum thrust of the gas turbine engine is provided at cruise thus the maximum thrust output of the gas turbine engine would be less than the thrust requirement in at least take-off”). In order to arrive at the Examiner’s determination that the maximum thrust output of the turbine engine of Anghel is less than the aircraft thrust requirement during a takeoff or top of climb mode of operations, one must presume the disclosure in Anghel regarding operating “most efficiently during ‘cruise’ operations” allows equating the maximum efficiency of the gas turbine engine to the maximum thrust of the turbine engine. Although the Examiner has relied on the disclosures in Gulen and McCombs to bridge that gap, Gulen merely discloses that maximum temperature is an import parameter in efficiency, while McCombs merely states that “[i]n order to obtain optimum thermal efficiency and maximum thrust, the turbine inlet temperature is maintained as close to the allowable limits as possible.” McCombs, col. 3, ll. 48-50. It is not clear that the simple statement in McCombs is establishing, as fact, equivalence between optimum thermal efficiency and maximum thermal efficiency, much less maximum thrust for the entire gas turbine engine. Indeed, the statement in McCombs may be understood as referring Appeal 2021-003596 Application 15/200,149 12 to maximizing thrust at the stated optimum thermal efficiency. Moreover, it is not entirely clear that the efficiency of fuel consumption referred to in Anghel can be equated with “thermal efficiency” referred to in McCombs. In other words, the Examiner has equated efficiency of fuel consumption referred to in Anghel with “optimum thermal efficiency and maximum thrust” disclosed in McCombs. We are not confident that such equivalence has been established by the limited evidence presented and relied upon. Thus, we agree with the Appellant that the Examiner’s reasoning used to reach the finding that in Anghel, “the maximum thrust output of the core is less than an aircraft thrust requirement on the gas turbine engine in at least one of the takeoff mode of operations and the top of climb mode of operations,” is based on erroneous understanding of Anghel and/or requires too many inadequately supported inferences. Therefore, we reverse the Examiner’s rejection of independent claim 1 as well as claims 2-4, 6-8, and 11 that ultimately depend from claim 1. The remaining arguments of the Appellant in rebuttal to the Answer are moot. See Reply Br. 1-2. Rejections 7-9: Claims 1, 2, 5, and 9 These rejections apply Moniz as the primary reference, but otherwise apply Anghel, Gulen, and McCombs in the same manner as Rejection 2. Final Act. 23-30. According, we reverse these rejections of claims 1, 2, 5, and 9 for the reasons discussed above relative to Rejection 2. Rejection 10: Claim 20 The Examiner rejects independent claim 20 as being unpatentable over Anghel in view of Gulen, Fukuda, and McCombs. Final Act. 31. Appeal 2021-003596 Application 15/200,149 13 Claim 20 contains the same limitation at issue in claim 1. The Examiner’s further reliance on Fukuda fails to address the above discussed deficiency as to the combination of Anghel, Gulen, and McCombs. Therefore, we reverse this rejection of claim 20. Rejection 1: Double Patenting Claims 1 and 9-11 are provisionally rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1, 5, 7, and 8 of co-pending Application No. 15/200,128 (March 9 and 12, 2020) in view of Anghel, Gulen, and Webster. Final Act. 3. The Appellant points out that “neither application includes allowed claims,” and states that upon “receiv[ing] allowed claims that are still subject to the double patenting rejection, Appellant will consider a terminal disclaimer at that time.” Appeal Br. 4. Nonetheless, the Appellant argues that “[s]hould the Board be convinced by Appellant’s arguments on the 103 rejection, the provisional double patenting rejection should be overcome for the same reasons.” Appeal Br. 4. Indeed, the provisional nonstatutory double patenting rejection is based on the same findings and reasoning set forth in the above- discussed obviousness rejections relative to Anghel, which we find deficient. Final Act. 3-4. Accordingly, we reverse the double patenting rejection. Appeal 2021-003596 Application 15/200,149 14 CONCLUSION The Examiner’s rejections are reversed. DECISION SUMMARY In summary: Claims Rejected 35 U.S.C. § Reference(s)/Basis Affirmed Reversed 1, 9-11 Provisional Nonstatutory Double Patenting Application No. 15/200,128, Anghel, Gulen, Webster 1, 9-11 1, 2 103 Anghel, Gulen, McCombs 1, 2 3, 4, 6 103 Anghel, Gulen, McCombs, Krug 3, 4, 6 7 103 Anghel, Gulen, McCombs, Krug, Hoffjann 7 8 103 Anghel, Gulen, McCombs, Hoffjann 8 11 103 Anghel, Gulen, McCombs, Fukuda 11 1, 2 103 Moniz, Anghel, Gulen, McCombs 1, 2 5 103 Moniz, Anghel, Gulen, McCombs, Michalko, Kupratis 5 9 103 Moniz, Anghel, Gulen, McCombs, Kupratis 9 20 103 Anghel, Gulen, Fukuda, McCombs 20 Appeal 2021-003596 Application 15/200,149 15 Overall Outcome 1-9, 11, 20 REVERSED