Ex Parte Hao et al

Patent Trial and Appeal BoardAug 31, 2017

13777572 (P.T.A.B. Aug. 31, 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. 13/777,572 02/26/2013 Lei Hao P020373-RD-SDJ 1736 65798 7590 09/01/2017 MILLER IP GROUP, PLC GENERAL MOTORS CORPORATION 42690 WOODWARD AVENUE SUITE 300 BLOOMFIELD HILLS, MI 48304 EXAMINER CHAN, RAWING ART UNIT PAPER NUMBER 2837 MAIL DATE DELIVERY MODE 09/01/2017 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 LEI HAO and CHANDRA S. NAMUDURI Appeal 2016-006222 Application 13/777,572 Technology Center 2800 Before CATHERINE Q. TIMM, JAMES C. HOUSEL, and AVELYN M. ROSS, Administrative Patent Judges. TIMM, Administrative Patent Judge. DECISION ON APPEAL1 STATEMENT OF CASE Pursuant to 35 U.S.C. § 134(a), Appellants2 appeal from the Examiner’s decision to reject claims 1—20 under 35 U.S.C. § 103(a) as obvious over Ueki3 in view of Bush.4 We have jurisdiction under 35 U.S.C. § 6(b). 1 In explaining our Decision, we cite to the Specification dated February 26, 2013 (Spec.), Final Office Action dated June 5, 2015 (Final), the Appeal Brief dated October 30, 2015 (Appeal Br.), the Examiner’s Answer dated March 24, 2016 (Ans.), and the Reply Brief dated May 19, 2016 (Reply Br.). 2 Appellants identify the real party in interest as General Motors. Appeal Br. 3. 3 Ueki, US 5,350,987, issued Sept. 27, 1994. 4 Bush et al., US 2002/0105301 Al, published Aug. 8, 2002. Appeal 2016-006222 Application 13/777,572 We AFFIRM. The claims are directed to a drive system for a permanent magnet (PM) electric machine (see, e.g., claims 1,11, and 15). The machine includes a stator, a rotor, and an inverter/rectifier circuit as is found in the traditional three-phase PM electric machine. See Spec. 1 10-11, 20-22; Figs. 1—2. As shown in Figure 1, the stator includes three windings 16, 18, 20 and the rotor includes a magnet 14. The magnetic flux of the magnet and current within the windings interact to drive machine 12. Spec. 120. The inverter/rectifier circuit 22 includes diodes 24 that rectify the AC current generated by the windings to a DC current to charge a vehicle battery. Spec. 120. The circuit 22 also converts the DC current from the battery 26 to an AC current when the machine is operating as a motor to, for example, start the vehicle. Id. The DC-to-AC conversion is accomplished using switches 28. Id. Appellants add a switch assembly to the known inverter/rectifier circuit 22 of Figure 1. This is shown in Figure 3 as a pair of bidirectional switches 66, 68. Spec. 123 (switches 54, 56 represent two of the switches 28 in Fig. 1). Appellants also separate each winding into two winding sections. Id. Figure 3 illustrates one of these separated windings at 62 and 64. Figure 3 is reproduced below: 2 Appeal 2016-006222 Application 13/777,572 Figure 3 is a schematic diagram of a reconfigurable winding electric drive system By selectively opening and closing the switches 66, 68 of the switch assembly, one can control the flow of current through the winding sections 62, 64. Specifically, when switch 66 is closed and switch 68 is open, current travels through the winding sections 62 and 64 in series. Id. When switch 66 is open and switch 68 is closed, current only travels through winding section 64 and not through winding section 62. Id. We reproduce claim 1 with reference numerals from Figures 1—3 to further illustrate the drive system: 1. A drive system [50; Fig. 3] for a permanent magnet (PM) electric machine [10; Fig. 1], said machine [10] including a stator [42; Fig. 2], a rotor [36; Fig. 2] and an inverter [22; Fig. 1], said drive system [50] comprising: at least one stator winding [62, 64; Fig. 3] in the stator [42] including a first winding section [62] and a second winding section [64]; 3 Appeal 2016-006222 Application 13/777,572 at least two inverter switches [54, 56; Fig. 3] in the inverter [22; Fig 1 (inverter switches labeled 28 in Fig. 1)] electrically coupled to the first and second winding sections [62, 64]; and a switch assembly [66, 68] electrically coupled to the inverter switches [54, 56] and the first and second winding sections [62, 64], said switch assembly [66, 68] including at least two switch states where a first switch state [66 closed, 68 open] electrically couples the first winding section and the second winding section in series to the inverter switches [54, 56] and a second switch state [66 open, 68 closed] electrically couples the second winding section [64] to the inverter switches [54, 56] and electrically disconnects the first winding section [62] from the inverter switches [54, 56]. Claims Appendix, Appeal Br. 22. OPINION Appellants argue claims 1,11, and 15 as a group. Appeal Br. 13—17. Appellants reproduce the dependent claims, but do not argue any of the claims sufficiently separately to give rise to an additional issue to be reviewed on appeal. Appeal Br. 17—20. Thus, we select claim 1 as representative for deciding the issues on appeal. Appellants’ arguments focus on the Examiner’s findings with regard to: (1) the inverter; (2) the electrical coupling to first and second winding sections; (3) the second state of the switch assembly; and (4) the combinability of the teachings of Ueki and Bush. Appeal Br. 13—17; Reply Br. 1—3. After considering the Examiner’s findings and conclusions in light of the arguments and evidence presented by Appellants, we determine that Appellants have not identified a reversible error in the Examiner’s rejection. 4 Appeal 2016-006222 Application 13/777,572 There is no dispute that Ueki discloses a drive system for a permanent magnet (PM) machine including a stator and a rotor or that the stator includes windings. Compare Final 3, with Appeal Br. 10. As can be seen from Ueki’s Figure 1, the stator windings may be of the three-phase type with 3 windings U, V, W. Ueki Fig. 1; col. 4,11. 43 46. Each winding may be divided into sub windings such that, for instance, winding U consists of sub winding U1 and sub winding U2 as shown in Figure 12. Ueki col. 13,11. 31-39, 56-67. Figures 3 and 4 show that one end of each of the windings U, V, W is connected to a current switching circuit 5. Ueki Figs. 3^4; col. 6,11. 58—63. Given the entirety of the disclosure, it follows that analogous connections to the switching circuit 5 would be made to one end of each of the Figure 12 windings, i.e., at V for windings VI and V2. The Examiner finds that Ueki’s current switching circuit 5 is an inverter with at least two inverter switches. Final 3; Ans. 3. Appellants contend that Ueki does not include an inverter as inverters are not used for DC motors. Appeal Br. 14. Thus, a question on appeal is whether Appellants have identified a reversible error in the Examiner’s finding that Ueki’s current switching circuit 5 is an inverter. After considering all the evidence and argument, we determine that Appellants have not identified such an error. The Examiner provides evidence that an inverter is “a device for converting direct current into alternating current.” Ans. 3 (quoting merriam- webster.com/dictionary/inverter). According to the Examiner, “[i]n Figure 4, Ueki discloses a circuitry (5) that changes direct current (Vcc) to alternating current for supplying power to a brushless DC motor (31).” 5 Appeal 2016-006222 Application 13/777,572 Ans. 3. This is a reasonable reading of Ueki. Ueki discloses that Vcc denotes DC power supply line voltage and the current switching circuit 5 supplies current sequentially to two of the three windings. Ueki col. 6,1. 67—col. 7,1. 15; col. 13,11. 26—27. Appellants provide no evidence or explanation to support their statement that “inverters are not used for DC motors,” nor do Appellants address the Examiner’s explanation detailed above. We determine that a preponderance of the evidence supports the Examiner’s finding that current switching circuit 5 is an inverter. Appellants further contend that Ueki does not teach at least two inverter switches in the inverter electrically coupled to the first and second winding sections and that Bush does not teach the second switch state of the claims. Appeal Br. 13,16. These arguments fail to persuade us that the Examiner reversibly erred. This is because the Examiner does not rely on either reference alone, but on Ueki in combination with Bush. Final 3^4. Ueki teaches the conventional circuit with two switches connected to each winding phase, e.g., switches 16, 19 connected to winding V (or sub windings VI and V2). Ueki Fig. 4; Fig. 12a. Bush teaches a three-phase motor with leads 58, 60, 62 that are in the position at which one of ordinary skill in the art would have connected the switches of Ueki. Together Ueki and Bush suggest electrically coupling the first and second winding sections of each winding (e.g., windings 64, 66) through the leads to the switches (e.g., electrically coupling winding sections 64, 66 of Bush through lead 58 to switches 16, 19). We also agree with the Examiner that the second switch state is taught because the “shorting out” taught by Bush is functionally equivalent to disconnecting the first winding section 66. Ans. 4. 6 Appeal 2016-006222 Application 13/777,572 Appellants have not persuaded us of a reversible error in the Examiner’s determination that one of ordinary skill in the art would have included the switch assembly 78 of Bush electrically coupled to the windings as taught by Bush in the inverter (current switching circuit 5) of Ueki “so as to provide maximum efficiency or to provide maximum torque output at maximum load point as required” as taught by Bush. Final 4 (citing Bush Abstract, | 8). The result of the combination would be a brushless DC motor with Ueki’s improved method of detecting a position of the rotor when the rotor is stationary (Ueki col. 2,11. 13—16) and also having the improved maximum efficiency and maximum torque at maximum load point as taught by Bush (Bush | 8). Appellants have not identified a reversible error in the Examiner’s rejection. CONCLUSION We sustain the Examiner’s rejection. DECISION The Examiner’s decision is affirmed. TIME PERIOD FOR RESPONSE 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 7