Ex Parte Frost et al

Patent Trial and Appeal BoardOct 31, 2012

11467585 (P.T.A.B. Oct. 31, 2012)

UNITED STATES PATENT AND TRADEMARKOFFICE 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. 11/467,585 08/28/2006 Patrick Frost GP-307402-GAPR-CHE 3800 65798 7590 11/01/2012 MILLER IP GROUP, PLC GENERAL MOTORS CORPORATION 42690 WOODWARD AVENUE SUITE 200 BLOOMFIELD HILLS, MI 48304 EXAMINER LEONG, JONATHAN G ART UNIT PAPER NUMBER 1725 MAIL DATE DELIVERY MODE 11/01/2012 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 PATRICK FROST, MANISH SINHA and JASON R. KOLODZIEJ ____________ Appeal 2011-008636 Application 11/467,585 Technology Center 1700 ____________ Before ADRIENE LEPIANE HANLON, HUBERT C. LORIN, and JEFFREY T. SMITH, Administrative Patent Judges. SMITH, Administrative Patent Judge. DECISION ON APPEAL Appeal 2011-008636 Application 11/467,585 2 STATEMENT OF THE CASE This is an appeal under 35 U.S.C. § 134 from the final rejection of claims 1 through 5, 10 through 13, 18 and 19. We have jurisdiction under 35 U.S.C. § 6. Appellants’ claimed invention relates to a method for determining whether flow channels of a fuel cell in a fuel cell stack are flooded. App.Br. 7. Claim 1 is illustrative: 1. A method for determining whether flow channels of a fuel cell in a fuel cell stack are flooded, indicating cell instability, said method comprising: providing pulses of a cathode reactant gas flow to cathode flow channels within the fuel cell stack; collecting data points of the voltage of each fuel cell in the fuel cell stack in response to the pulse of cathode reactant gas flow for a predetermined period of time; using a pattern recognition algorithm to determine whether the collected data points indicate a voltage signature for each fuel cell identifying flooded cathode flow channels or non-flooded cathode flow channels; and increasing how often the cathode air flow pulses are provided if the pattern recognition algorithm determines that one or more of the cells has flooded cathode flow channels. The Examiner relied on the following references in rejecting the appealed subject matter: Meltser US 5,945,229 August 31, 1999 Wells US 2003/0022042 A1 January 30, 2003 Takeguchi US 2004/0157103 A1 August 12, 2004 Appeal 2011-008636 Application 11/467,585 3 M.J. Martin et al., Application of Pattern Recognition to the Discrimination of Roasted Coffees", 320 ANALYTICA CHIMICA ACTA 191 (1996). Appellants request review of the following rejection (App. Br. 10) from the Examiner’s final office action: 1. Claims 1, 2, 10, 11 and 18 stand rejected under 35 U.S.C. § 103(a) as being unpatentable over Meltser and Wells. 2. Claims 3-5, 12, 13, and 19 stand rejected under 35 U.S.C. § 103(a) as being unpatentable over Meltser, Wells and either Takeguchi or Martin. OPINION The dispositive issue for this appeal is: Did the Examiner err in determining that the combination of Meltser and Wells would have led one skilled in the art to a method for determining whether flow channels of a fuel cell in a fuel cell stack are flooded by collecting data points of the voltage of each fuel cell in the fuel cell stack in response to the pulse of cathode reactant gas flow as required by the subject matter of independent claims 1, 10 and 18? 1, 2 After thorough review of the respective positions provided by Appellants and the Examiner, we answer in the affirmative and REVERSE for the reasons presented by the Appellants and add the following. 1 We focus our discussion on independent claim 1. 2 A discussion of the Takeguchi and Martin references is unnecessary for disposition of this appeal because Appellants indicated that claims 3-5, 12, 13 and 19 stand or fall with their respective independent claims. App. Br. 10. Appeal 2011-008636 Application 11/467,585 4 We refer to the Examiner’s Answer for a statement of the Examiner’s rejection (Ans. 4-10).3 The Examiner found that Meltser discloses a method for determining whether flow channels of a fuel cell in a fuel cell stack are flooded by collecting data points for a predetermined period of time of the voltage of a fuel cell and using a pattern recognition algorithm to determine whether collected data points indicate a voltage signature identifying flooding in the cathode flow channels. Id. at 4. The Examiner also found that Meltser discloses providing pulses of a cathode reactant gas flow to cathode flow channels within the fuel cell stack to cure the flooding in the cathode flow channels. Id. at 4, 14; Meltser col. 11, ll. 20-24. The Examiner found that Meltser does not explicitly disclose collecting data points of the voltage of each fuel cell in the fuel cell stack in response to the pulse of cathode reactant gas flow. Id. at 4. The Examiner relied on Wells to teach measuring of the voltage across fuel cells and pulsing of reactant gas to remove excess water from the cathode flow channels when a fuel system undergoes flooding. Id. at 4-5. The Examiner concluded that it would have been obvious to one of ordinary skill in the art “to incorporate the teachings of Wells, namely, monitoring the voltage of each fuel cell in the fuel cell stack and pulsing the cathode reactant gas flow during low load, into the method of Meltser in order to ensure that all of the fuel cells are monitored for potential cathode flooding problems and to prevent or reduce problems associated with cathode flooding during low load operation…so that the 3 We note that the Examiner did not repeat the appealed rejection of claims 3-5, 12, 13 and 19 in the Answer. However, we consider the rejection to be before us for review because Appellants are appealing the Examiner’s decision in the Final Office Action. App. Br. 1, 10. Appeal 2011-008636 Application 11/467,585 5 method as disclosed by Meltser inherently collects data points of the voltage of each fuel cell in the fuel cell stack in response to the pulse of cathode reactant gas flow” Id. at 5. Appellants argue that neither Meltser nor Wells teaches or suggests collecting voltage data points in response to the pulse of the cathode reactant gas. App. Br. 12, 15. Appellants further argue that the cathode reactant gas pulse of Meltser and Wells is in response to clearing a flood condition and not to monitor voltage during the pulse to determine a flooding condition. Id. at 16. We agree with Appellants that the combination of Meltser and Wells would not have led one skilled in the art to Appellants’ method as set forth in independent claim 1. Id. at 12. As correctly noted by Appellants, both Meltser and Wells disclose pulsing of the cathode reactant gas to clear the flooding from the cathode flow channels. Id. at 16, Meltser col. 11, ll. 20-24; Wells ¶ [0080]. Neither reference discloses monitoring fuel cell performance by collecting voltage data points in response to a pulse of cathode reactant gas. App. Br. 12, 15. On the other hand, Appellants’ claimed invention requires pulsing of the cathode reactant gas to generate voltage data points used to monitor fuel cell performance. Claim 1; App. Br. 7-8. While the Examiner contends that Meltser discloses collecting voltage data points in response to a pulse of cathode reactant gas (Ans.11), the Examiner has not directed us to evidence in Meltser that supports this contention. Further, the Examiner has not adequately explained how one skilled in the art would modify the fuel cell monitoring process of Meltser to generate voltage data points from pulses of a cathode reactant gas as required by the subject matter of independent claim 1. On the present Appeal 2011-008636 Application 11/467,585 6 record, the Examiner has failed to meet the initial burden of establishing a prima facie case of obviousness. See In re Oetiker, 977 F.2d 1443, 1445 (Fed. Cir. 1992). For the reasons stated above and those presented by Appellants, the rejection of claims 1, 2, 10, 11 and 18 under 35 U.S.C. § 103(a) as being unpatentable over Meltser and Wells is reversed. We also reverse the separate rejection of claims 3-5, 12, 13 and 19 under 35 U.S.C. § 103(a) as being unpatentable over Meltser, Wells and either Takeguchi or Martin for the same reasons. ORDER The rejection of claims 1, 2, 10, 11 and 18 under 35 U.S.C. § 103(a) as being unpatentable over Meltser and Wells is reversed. The rejection of claims 3-5, 12, 13 and 19 under 35 U.S.C. § 103(a) as being unpatentable over Meltser, Wells and either Takeguchi or Martin is reversed. REVERSED bar