Ex Parte Patel et alDownload PDFPatent Trial and Appeal BoardAug 6, 201813091705 (P.T.A.B. Aug. 6, 2018) Copy Citation UNITED STA TES p A TENT AND TRADEMARK OFFICE APPLICATION NO. FILING DATE 13/091,705 04/21/2011 88326 7590 Kinney & Lange, P.A. 312 South Third Street Minneapolis, MN 55415 08/08/2018 FIRST NAMED INVENTOR Tejendra Patel 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 ATTORNEY DOCKET NO. CONFIRMATION NO. 58299US01-U74-012265 5131 EXAMINER COMINGS, DANIEL C ART UNIT PAPER NUMBER 3744 NOTIFICATION DATE DELIVERY MODE 08/08/2018 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): USPatDocket@kinney.com amkoenck@kinney.com PTOL-90A (Rev. 04/07) UNITED STATES PATENT AND TRADEMARK OFFICE BEFORE THE PATENT TRIAL AND APPEAL BOARD Ex parte TEJENDRA PATEL, JEFFREY ERNST, BRUCE R. SCHRODER, ROBERT M. DEROY, and KODJOVI COUSSEY Appeal2017-009851 Application 13/091,705 1 Technology Center 3700 Before LINDA E. HORNER, EDWARD A. BROWN, and JEREMY M. PLENZLER, Administrative Patent Judges. HORNER, Administrative Patent Judge. DECISION ON APPEAL STATEMENT OF THE CASE Appellants seek our review under 35 U.S.C. § 134(a) of the Examiner's decision rejecting claims 1-23. Final Office Action (December 22, 2015) (hereinafter "Final Act."). We have jurisdiction under 35 U.S.C. § 6(b). 1 Tejendra Patel et al. ("Appellants") identify Hamilton Sundstrand Corporation as the real party in interest. Appeal Brief (May 20, 2016) (hereinafter "Br."), at 2. Appeal2017-009851 Application 13/091,705 The claimed subject matter relates to "control algorithms used to regulate the position of the [ electronic expansion valves]" in refrigeration systems. Specification (April 21, 2011) (hereinafter "Spec."), ,r 1. The Examiner rejected the claims as obvious over the prior art. For the reasons explained below, we find error in the Examiner's rejections. Accordingly, we REVERSE. CLAIMED SUBJECT MATTER Claims 1, 10, and 17 are the independent claims on appeal. Claim 1 is illustrative of the claimed subject matter and is reproduced below with disputed limitations italicized for emphasis. 1. A method of controlling position of an electronic expansion valve (EEV) employed in a refrigeration system, the method comprising: generating, by a processing unit, a first EEV position control signal based on superheat feedback associated with the refrigeration system in a first control loop; generating, by the processing unit, a second EEV position control signal based on pressure feedback associated with the refrigeration system in a second control loop; comparing, by the processing unit, the first EEV position control signal and the second EEV position control signal; selecting, by the processing unit based on the comparison of the first EEV position control signal and the second EEV position control signal, either the first EEV position control signal or the second EEV position control signal as a selected position control signal employed to control position of the EEV; providing, by the processing unit, the selected position control signal in feedback to both the first control loop and the second control loop; outputting, by the processing unit, the selected position control signal to modify a position of the EEV; and 2 Appeal2017-009851 Application 13/091,705 modifying, based on the outputted selected position control signal, the position of the EEV. Br. 15 (Claims Appendix). Nickell Tenedini McCulloch Jessen McCormick Koehl Kawakatsu EVIDENCE us 4,069,030 us 4,547,977 us 4,689,968 US 2004/0068999 Al US 2006/0059926 Al US 7,612,510 B2 US 2010/0064723 Al REJECTIONS Jan. 17, 1978 Oct. 22, 1985 Sept. 1, 1987 Apr. 15, 2004 Mar. 23, 2006 Nov. 3, 2009 Mar. 18, 2010 The Final Office Action includes the following rejections under pre-AIA 35 U.S.C. § I03(a): 1. Claims 1, 2, 9-11, 16-18, and 21-23 stand rejected as unpatentable over Kawakatsu, McCormick, and Nickell. 2. Claims 3, 4, 6, 12, 14, and 20 stand rejected as unpatentable over Kawakatsu, McCormick, Nickell, Jessen, and McCulloch. 3. Claims 5 and 13 stand rejected as unpatentable over Kawakatsu, McCormick, Nickell, Jessen, McCulloch, and Tenedini. 4. Claims 7, 8, and 15 stand rejected as unpatentable over Kawakatsu, McCormick, Nickell, and Koehl. 5. Claim 19 stands rejected as unpatentable over Kawakatsu, McCormick, Nickell, and Tenedini. ANALYSIS In the rejection of independent claim 1, the Examiner found that Kawakatsu teaches a method of controlling the position of an EEV, including generating a first EEV position control signal ( either S6 or S8) and 3 Appeal2017-009851 Application 13/091,705 generating a second EEV position control signal ( either S2 or S4 ). Final Act. 3 ( citing Kawakatsu, Fig. 2). The Examiner also found that the method of Kawakatsu includes selecting either the first or the second EEV position control signal as the selected position control signal. Id. at 3-4. The Examiner found that Kawakatsu does not disclose comparing these two signals to each other for selecting the signal to be used in controlling the position of the EEV. Id. at 4. The Examiner relied on Nickell to teach a controller for a refrigeration cycle system in which a pair of control signals are compared to each other and the output of the comparison is used in the control of a valve of the system. Id. The Examiner determined that it would have been obvious "to modify Kawakatsu with the signal comparison control of Nickell in order to more directly achieve [] a control scheme such as that taught by Kawakatsu through direct comparison of the signals to one another in order to provide a less complex and thus more robust control system." Id. at 4-5. The Examiner relied on these same findings and reasoning as the basis for the rejection of independent claims 10 and 17. Id. at 6. 2 Appellants argue that the Examiner erred in rejecting the claims because Nickell does not disclose comparing control signals, and because the Examiner failed to articulate adequate reasoning based on rational underpinnings for the proposed modification of Kawakatsu with the teaching of Nickell. Br. 7-11. As to the former, Appellants assert that "Nickell 2 The Examiner's finding as to the disclosure of McCormick and the proposed modification of Kawakatsu with McCormick are not at issue in this appeal. Final Act. 4 (Examiner finding McCormick teaches valve position feedback), Br. 11-12 (Appellants not contesting this finding as to McCormick). 4 Appeal2017-009851 Application 13/091,705 discloses a system in which measured pressure signals corresponding to outside air enthalpy and return air enthalpy can be compared by a differential pressure switch to activate an air solenoid valve for operation of a cooling system." Id. at 7. As to the latter, Appellants assert that "Kawakatsu merely discloses a series of threshold checks that can be utilized to control the opening and closing of the electronic expansion valve." Br. 10. According to Appellants, "Kawakatsu illustrates and describes that each threshold check that results in a control command bypasses each of the other threshold checks. As such, Kawakatsu discloses the generation of, at most, one command configured to control the electronic expansion valve during any given execution of the operations of FIG. 2." Id. Thus, Appellants contend that the art relied on by the Examiner does not suggest why a comparison of the control commands in Kawakatsu would "more directly achieve the control scheme as that taught by Kawakatsu" or "provide a less complex and thus more robust control system" as asserted by the Examiner. Id. at 11. We agree with Appellants on both counts. First, Nickell does not disclose comparing control signals. We look to Appellants' Specification for a discussion of the claimed control signals. The Specification describes two control loops 40, 42, which receive as inputs monitored temperature and/or monitored pressure of the refrigerant output from the evaporator. Spec. ,r 15. In each control loop, the input temperature and/or pressure is provided to a calculator that calculates a value based on these inputs and/ or compares the value to a desired value to calculate an error based on the difference between the calculated and the desired values. Id. ,r,r 15-17. The calculated error is provided to a PI control block, which determines a step 5 Appeal2017-009851 Application 13/091,705 output that represents the desired position of the EEV. Id. ,r,r 16-17. This step output value is output by the PI control block as a position control signal. Thus, the position control signals compared in selector block 54 are the step output signals generated by the PI control block. Id. By contrast, in Nickell, measurements of enthalpy, represented using pressure, are sent from return air transmitter 46 and outside air transmitter 51 to differential pressure switch 48 to select a source of air to use in the air conditioner. Nickell, col. 5, 11. 15-27. The pressures compared in Nickell's differential pressure switch are not control signals. Rather, the inputs to Nickell' s differential pressure switch are enthalpy measurements, akin to temperature and pressure measurements input into the control loops of Appellants' invention. Second, the Examiner's articulated reasoning for modifying Kawakatsu in the manner claimed lacks rational underpinnings. Kawakatsu discloses a refrigeration system for a marine container that uses either a water-cooled condenser or an air-cooled condenser as a cold heat source to condense refrigerant. Kawakatsu ,r 1. Kawakatsu explains that the amount of refrigerant the refrigerant circuit requires generally is less in the water- cooled operation mode than in the air-cooled operation mode. Id. ,r 6. Kawakatsu's method avoids the possibility of a high-pressure condition developing due to surplus refrigerant accumulated in the water-cooled condenser when the system is in the water-cooled operation mode. Id. In particular, Kawakatsu describes using the degree of superheat of the evaporator to control the degree of opening of the EEV, except in the case where the high pressure abnormally increases during the water-cooled operation mode. Id. ,r 7. In such an instance, the degree of opening of the 6 Appeal2017-009851 Application 13/091,705 EEV is forcibly decreased to reduce the refrigerant circulation amount to prevent an increase in the high pressure of the refrigerant circuit. Id.; see also id. ,r 12. Thus, in Kawakatsu's method, the high-pressure condition overrides the normal control of the EEV based on the superheat condition, as shown in the flowchart of Figure 2 of Kawakatsu. See also id. ,r,r 55-56 ( describing Fig. 2). In other words, in Kawakatsu, if the high pressure detected by the high-pressure sensor exceeds a specified pressure threshold, then a control command is sent to the EEV to forcibly decrease the degree of opening of the EEV, and the system bypasses steps S5-S8, which check the degree of superheat. Id. Thus, as argued by Appellants, in Kawakatsu's method, each threshold check that results in a control command bypasses each of the other threshold checks. Kawakatsu, Fig. 2. The Examiner has failed to explain adequately why one having ordinary skill in the art would recognize an improvement to Kawakatsu's method by comparing the high-pressure condition signals with the superheat condition signals. Specifically, we do not see how directly comparing these two signals would result in a "less complex" and "more robust control system" as asserted by the Examiner. Further, the Examiner has not explained adequately how the teachings of Nickell would have led one to make the proposed modification. As discussed briefly above, Nickell relates to a control system for an air conditioner that compares measurements of enthalpy in the outside air and enthalpy in the return air to determine which source of air to use in the air conditioner to consume the least amount of energy. Nickell, col. 3, 11. 8-29. Nickell' s system improves the prior art by providing sensing units capable of reliably measuring the wet bulb temperature of each air source to provide an 7 Appeal2017-009851 Application 13/091,705 accurate calculation of enthalpy. Id. at col. 4, 11. 55-57. It is not readily apparent, and the Examiner has not sufficiently explained, how Nickell's teaching of comparing measurements representing enthalpy of different air sources, would have led one having ordinary skill in the art to modify Kawakatsu's method to compare signals representative of a high-pressure condition and signals representative of a superheat condition to control an EEV. In other words, the Examiner has not explained why a skilled artisan would have been led to compare Kawakatsu's signals, as opposed to using the high-pressure condition as the overriding control condition. For these reasons, we do not sustain the rejection of independent claims 1, 10, and 17, and their dependent claims 2, 9, 11, 16, 18, and 21-23, as unpatentable over Kawakatsu, McCormick, and Nickell. The remaining grounds of rejection of dependent claims 3-8, 12-15, 19, and 20, also rely on the above-noted deficiencies in the rejection of the independent claims based on Kawakatsu as modified by Nickell. As such, we also do not sustain rejections of these dependent claims. DECISION The decision of the Examiner rejecting claims 1-23 is reversed. REVERSED 8 Copy with citationCopy as parenthetical citation