Ex Parte Glahn et al

Patent Trial and Appeal BoardAug 8, 2017

13444898 (P.T.A.B. Aug. 8, 2017)

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. 13/444,898 04/12/2012 Jorn A. Glahn 60804US02; 5670 67097-1753PUS1 54549 7590 08/10/2017 CARLSON, GASKEY & OLDS/PRATT & WHITNEY 400 West Maple Road Suite 350 Birmingham, MI 48009 EXAMINER MCCAFFREY, KAYLA M ART UNIT PAPER NUMBER 3745 NOTIFICATION DATE DELIVERY MODE 08/10/2017 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 JORN A. GLAHN, WILLIAM K. ACKERMANN, PHILIPS S. STRIPINIS, JOHN T. SCHMITZ, and CLIFTON J. CRAWLEY Jr. Appeal 2016-005797 Application 13/444,898 Technology Center 3700 Before ROBERT E. NAPPI, JOSEPH P. LENTIVECH and SCOTT B. HOWARD, Administrative Patent Judges. PER CURIAM DECISION ON APPEAL This is a decision on appeal under 35 U.S.C. § 134(a) from the final rejection of claims 1, 2, 5 through 12, and 14 through 21. We have jurisdiction under 35 U.S.C. § 6(b). We affirm. INVENTION This invention is directed to a gas turbine engine that has a thrust- balance chamber between a static housing and a rotating component. The thrust-balance chamber is sealed by non-contact seals. Claim 1 is illustrative of the invention and reproduced below. Appeal 2016-005797 Application 13/444,898 1. A gas turbine engine comprising: a turbine section and an air moving section upstream of the turbine section; a thrust balance chamber defined within one of said air moving and turbine sections, said thrust balance chamber being defined between a static structure and a rotating component that is part of at least one of said air moving section and said turbine section, and said thrust balance chamber being sealed by a first non-contact seal at a radially inner location and a second noncontact seal at a radially outer location; said turbine section driving a fan through a gear reduction; and said first and second non-contact seals each including a shoe which is biased radially inwardly and outwardly relative to a carrier at least in part based upon a spring force. REJECTION AT ISSUE1 The Examiner has rejected claims 1, 2, 5 through 12, and 14 through 21 under 35 U.S.C. § 103(a) as unpatentable over Rofka (US 2009/0067984 Al, published Mar. 12, 2009) and Justak (US 2008/0246223 Al, published Oct. 9, 2008).2 Final Act. 3—7. 1 Throughout this Decision we refer to the Appeal Brief, dated November 11, 2015 (“App. Br.”), the Reply Brief, dated May 10, 2016 (“Reply Br.”), the Examiner’s Answer, mailed April 4, 2016 (“Ans.”), and the Final Office Action, mailed June 15, 2015 (“Final Act.”). 2 We note the Examiner additionally relies upon Hawkins (US 6,183,388 Bl, issued Feb. 6, 2001) to demonstrate that it is well known that gas turbines have high and low pressure compressor and turbine sections. Also the Examiner relies upon Hawkins to demonstrate that is it known the use a gear reduction to couple the turbine to a fan which reduces shaft speed and increases torque. 2 Appeal 2016-005797 Application 13/444,898 ANALYSIS Appellants argue the claimed invention makes use of a unique location for a specific seal. App. Br. 3. Appellants argue that the geared fan provides a high bypass ratio which requires the air delivered to the compressor to be utilized more efficiently. Id. Appellants states: While Appellant does not contest that gear reductions for driving fan rotors were known prior to Appellant's filing date, such was not included in the Rofka, et al. engine. There is no reason to include such a device into Rofka, et al. Rofka, et al. discloses seals 9 and 8, however, it does not disclose the type of seals required by the claims. Instead, Rofka discloses a labrynth seal, or at paragraph 49, it discloses that a brush seal could replace the labyrinth seal. The Examiner argues that Justak discloses a seal which could be substituted for the seals of Rofka. However, the seals as disclosed in Justak were known prior to the filing date of Rofka, et al. and Rofka, et al. did not select such a seal for inclusion in its engine. As can be appreciated, the Justak seals are far more complicated than the simple seals disclosed in Rofka. In particular, since Rofka, et al. does not disclose a gear reduction, the air efficiency issues, and the small radial envelope issues discussed above would not exist. None of these issues would motivate utilizing the more complex seal of Justak into Rofka, et al. when there is no problem disclosed anywhere in this record other than Appellant's disclosure to support the combination. App. Br. 3^4. Thus, Appellants’ arguments present us with the issue of whether the Examiner erred in finding the skilled artisan would modify the Rofka’s turbine (which has a thrust-balanced chamber) to add a geared fan (as is well known as demonstrated by Hawkins) and hybrid seals as taught by Justak. 3 Appeal 2016-005797 Application 13/444,898 The Examiner’s rejection provides the rationale that the skilled artisan would use “a gear reduction which is reducing the high shaft speed of the turbine and increasing the output torque delivered to the fan.” Final Act 4. Further, the Examiner states the skilled artisan would use the seals of Justak as “modify the gas turbine engine of ROFKA by replacing the labyrinth seals with the shoe seals taught by JUSTAK in order to improve control of the clearance between the seal and the machine component, i.e. rotor or stator, thereby reducing wear rate and potential contamination (JUSTAK paragraph 0015-0016).” Final Act 4. Further, the Examiner provides a comprehensive response to Appellants arguments on pages 2 through 5 of the Answer. We have reviewed Appellants’ arguments in the Appeal Brief and the Reply Brief, the Examiner’s rejections, and the Examiner’s response to Appellants’ arguments. We agree with the Examiner’s findings and conclusions. Additionally, we note Appellants’ arguments do not address the rationale provided by the Examiner. Thus, Appellants’ arguments have not persuaded us of Examiner error in the Examiner’s rejections of claims 1, 2, 5 through 12, and 14 through 21. DECISION We sustain the Examiner’s rejections of claims 1, 2, 5 through 12, and 14 through 21 under 35 U.S.C. § 103(a). No time period for taking any subsequent action in connection with this appeal may be extended under 37 C.F.R. § 1.136(a)(l)(iv). AFFIRMED 4