Ex Parte Lebzelter et al

Patent Trial and Appeal BoardJun 24, 2014

12187056 (P.T.A.B. Jun. 24, 2014)

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. 12/187,056 08/06/2008 Derek R. Lebzelter P002218-FCA-CHE 2300 65798 7590 06/25/2014 MILLER IP GROUP, PLC GENERAL MOTORS CORPORATION 42690 WOODWARD AVENUE SUITE 300 BLOOMFIELD HILLS, MI 48304 EXAMINER MARKS, JACOB B ART UNIT PAPER NUMBER 1729 MAIL DATE DELIVERY MODE 06/25/2014 PAPER 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. PTOL-90A (Rev. 04/07) UNITED STATES PATENT AND TRADEMARK OFFICE ____________ BEFORE THE PATENT TRIAL AND APPEAL BOARD ____________ Ex parte DEREK R. LEBZELTER, BALASUBRAMANIAN LAKSHMANAN, and FREDERICK T. WAGNER __________ Appeal 2012-012129 Application 12/187,056 Technology Center 1700 ____________ Before KAREN M. HASTINGS, MICHAEL P. COLAIANNI, and GEORGE C. BEST, Administrative Patent Judges. COLAIANNI, Administrative Patent Judge. DECISION ON APPEAL Appellants appeal under 35 U.S.C. § 134 the final rejection of claims 1-20 and 22. We have jurisdiction over the appeal pursuant to 35 U.S.C. § 6(b). We REVERSE. Appellants’ invention is directed to a method for heating a fuel cell stack at system start-up that includes electrically shorting the stack and using cathode air as a limiting reactant (Spec. ¶ [0001]). Appeal 2012-012129 Application 12/187,056 2 Claim 1 is illustrative: 1. A method for heating a fuel cell stack at stack start-up, said method comprising: determining whether the temperature of the fuel cell stack is below a first predetermined temperature threshold; starting a cooling fluid flow through the stack if the stack temperature is below the first predetermined temperature threshold; engaging a shorting circuit across the stack to short circuit the stack and cause the stack to operate inefficiently; determining a desired heating rate of the fuel cell stack; calculating a cathode airflow to the fuel cell stack based on the desired heating rate; flowing the calculated cathode air to the cathode side of the fuel cell stack; measuring the temperature of the stack to determine whether the temperature is above a second predetermined temperature threshold; determining a minimum cell voltage if the temperature of the stack is below the second temperature threshold; reducing a flow of cathode air to the stack if the minimum cell voltage is below a predetermined minimum cell voltage threshold; and disengaging the shorting circuit and applying vehicle loads to the stack if the temperature of the stack is above the second temperature threshold. Appellants appeal the following rejections: 1. Claims 1-20 and 22 are rejected under 35 U.S.C. § 112, first paragraph, as failing to comply with the enablement requirement. 2. Claims 1-20 and 22 are rejected under 35 U.S.C. § 112, second paragraph, as failing to point out and particularly claim the subject matter which Appellants regard as the invention. Appeal 2012-012129 Application 12/187,056 3 REJECTION (1): Enablement ISSUE Did the Examiner reversibly err in concluding that the subject matter of claim 1 that includes the steps of “determining a desired heating rate of the fuel cell stack” and “calculating a cathode airflow to the fuel cell stack based on the desired heating rate” lacks enablement? We decide this issue in the affirmative. FINDINGS OF FACT AND ANALYSES The Examiner finds that the Specification fails to enable the claimed invention that requires “determining a desired heating rate of the fuel cell stack” and “calculating a cathode airflow to the fuel cell stack based on the desired heating rate” (Ans. 4-7). The Examiner performs an analysis of the factors set-forth in In re Wands, 858 F.2d 731, 737 (Fed. Cir. 1988) and finds that the breadth of the claims, the level of predictability in the art, the lack of working examples and quantity of experimentation needed based on Appellants’ disclosure factors weigh in favor of non-enablement (Ans. 5-7). The Examiner finds that Appellants’ Specification does not disclose any qualitative or quantitative mathematical correlation between the cathode airflow and the desired heating rate so that a person of ordinary skill would have to formulate such a correlation (Id. at 6-7). The Examiner finds Appellants do not disclose any working examples and a person of ordinary skill in the art would have no mathematical basis to know how to control the cathode air flow based on the desired heating rate. Id. The Examiner also finds that the claims do not recite “any limitation that is narrower than one quantity is calculated based on another” so that the breadth of the claims weighs in favor of a conclusion of nonenablement (Id. at 5). Appeal 2012-012129 Application 12/187,056 4 Appellants argue that based on the disclosures in ¶¶ 18, 20, 21, and 22 of the Specification, one skilled in the art could determine a desired heating rate and could also calculate a cathode airflow to the fuel cell based upon the desired heating rate without undue experimentation (App. Br. 11). Appellants contend that a person of ordinary skill in the fuel cell art would understand that based on stack characteristics such as the size of the stack and the thermal mass of the stack, and based on the temperature of the stack and ambient temperature, the desired heating rate can be determined (Id. at 12). Appellants argue that since hydrogen gas is disclosed as being at least stoichiometric amounts, a person skilled in the art could calculate for a given stack, a cathode airflow rate to achieve a desired heating rate. Id. Based on these disclosures, Appellants contend that a reasonable amount of guidance has been given with respect to the direction in which experimentation should proceed (Id.). We agree with Appellants that the Examiner erroneously concluded non-enablement. Appellants’ Specification at paragraphs 18, 20, 21, and 22 disclose that when the shorting switch 44 is closed the fuel cell operates inefficiently and yields almost exclusively heat (Spec. ¶¶ [0018]; [0020]). Appellants disclose that hydrogen supplied to the fuel cell is maintained in a stoichiometric excess over air flow to the stack (Spec. ¶ [0022]). Appellants further disclose that by controlling cathode airflow compressor 14 the amount of heat generated by the fuel cell stack 12 with the switch 44 closed can be controlled (Spec. ¶ [0018]). The Specification further discloses that various factors, such as thermal mass of the stack 12 and the ambient temperature, are used in determining the heating rate of the stack 12 (Spec. ¶ [0021]). Appeal 2012-012129 Application 12/187,056 5 Based on these disclosures, we conclude that Appellants’ claimed subject matter that includes the steps of “determining a desired heating rate of the fuel cell stack” and “calculating a cathode airflow to the fuel cell stack based on the desired heating rate” are enabled by the disclosed invention. We find that the Specification provides sufficient guidance to the ordinarily skilled artisan on how to determine the cathode airflow and the desired heating rate based on conventional chemical engineering principles. Specifically, the heat given off by the reaction of cathode air and hydrogen fuel could be determined by the skilled artisan based in part upon the stoichiometry of the reaction. The skilled artisan would have been enabled to determine the desired heating rate of the fuel cell stack based on the thermal capacity of the fuel cell stack and ambient temperature using conventional thermodynamic principles. The level of guidance provided by the Specification, in our opinion, sufficiently supports a conclusion that no undue experimentation would have been required by the ordinarily skilled artisan to practice the claimed subject matter. In re Wright, 999 F.2d 1557, 1562 (Fed. Cir. 1993). Nothing more than objective enablement is required, and therefore it is irrelevant whether this teaching is provided through broad terminology or illustrative examples. Id. In light of our findings and conclusions, we reverse the Examiner’s § 112, first paragraph rejection for lack of enablement. REJECTION (2): Indefiniteness The Examiner finds that claim limitations “determining a desired heating rate of the fuel cell stack” and “calculating a cathode airflow to the fuel cell stack based on the desired heating rate” are indefinite because Appeal 2012-012129 Application 12/187,056 6 Appellants do not particularly point out and distinctly claim the relationship between the desired heating rate and the step of calculating the cathode air flow (Ans. 7-8). We find that one of ordinary skill would understand what is claimed when the claims are read in light of the Specification. Orthokinetics, Inc. v. Safety Travel Chairs, Inc., 806 F.2d 1565, 1576 (Fed. Cir. 1986). As discussed above with regard to the enablement rejection, we find that the Specification provides sufficient guidance to the skilled artisan as to the relationship between the desired heating rate and the cathode airflow. Accordingly, we reverse the Examiner’s § 112, second paragraph, rejection1 using similar reasoning discussed supra. DECISION The Examiner’s decision is reversed. No time period for taking any subsequent action in connection with this appeal may be extended under 37 C.F.R. § 1.136(a)(1)(iv). ORDER REVERSED tc 1 We note that part of the Examiner’s § 112, second paragraph, rejection is based upon the lack of antecedent basis for the claim phrase “cathode air” (Ans. 8). While we agree that the wording is different, we find that one of ordinary skill in the art would have understood that “cathode air” in the phrase “flowing the calculated cathode air” should be “cathode airflow.” Nevertheless, if prosecution of the ’056 Application continues, Appellants should correct this oversight in the claim language.