Sathish Das et al.Download PDFPatent Trials and Appeals BoardSep 24, 20212021001764 (P.T.A.B. Sep. 24, 2021) Copy Citation 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. 13/822,817 03/13/2013 Sathish R. Das 54404US02 (U180002US2) 1708 87059 7590 09/24/2021 Cantor Colburn LLP - Carrier 20 Church Street, 22nd Floor Hartford, CT 06103 EXAMINER SHAIKH, MERAJ A ART UNIT PAPER NUMBER 3763 NOTIFICATION DATE DELIVERY MODE 09/24/2021 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): usptopatentmail@cantorcolburn.com PTOL-90A (Rev. 04/07) UNITED STATES PATENT AND TRADEMARK OFFICE BEFORE THE PATENT TRIAL AND APPEAL BOARD Ex parte SATHISH R. DAS, ADEYEMI A. ADEPETU, DON A. SCHUSTER, and RAJENDRA K. SHAH Appeal 2021-001764 Application 13/822,817 Technology Center 3700 Before CHARLES N. GREENHUT, ANNETTE R. REIMERS, and CARL M. DEFRANCO, Administrative Patent Judges. DEFRANCO, Administrative Patent Judge. DECISION ON APPEAL Pursuant to 35 U.S.C. § 134(a), Appellant1 appeals from the Examiner’s decision to reject claims 1–3, 5–13, and 15–20. Claims 4 and 14 are canceled. We have jurisdiction under 35 U.S.C. § 6(b). We affirm. CLAIMED SUBJECT MATTER The claimed subject matter relates to a refrigerant vapor compression system, and, more particularly, to “a system for stabilizing superheat based on ambient temperature and compressor speed to provide enhanced 1 We use the term “Appellant” to refer to “applicant” as defined in 37 C.F.R. § 1.42(a). Appellant identifies Carrier Corporation as the real party in interest. Appeal Br. 1. Appeal 2021-001764 Application 13/822,817 2 operation.” Spec. ¶ 2. Of the pending claims, claims 1 and 9 are independent, with claim 1 being directed to a “refrigerant vapor compression system” and claim 9 being directed to a “method of controlling” the system. Claim 1, reproduced below, is illustrative: 1. A refrigerant vapor compression system comprising: a compressor; an expansion valve; a compressor speed sensor operatively connected to the compressor; an evaporator outlet pressure sensor; an ambient temperature sensor; a controller operatively coupled to the expansion valve, compressor speed sensor, evaporator outlet pressure sensor, and ambient temperature sensor, the controller including a superheat control configured to selectively activate the expansion valve to establish a desired superheat value based on evaporator outlet pressure, a speed of the compressor as sensed by the compressor speed sensor, and ambient temperature as sensed by the ambient temperature sensor; and wherein the controller includes a transient operation control that, upon detecting a transient system change, establishes a predicted expansion valve position based on the sensed transient system change, waits for a waiting period, determines if the refrigerant vapor compression system has achieved stable operation, resets the predicted expansion valve position when the refrigerant vapor compression system has not achieved stable operation and reverts to the superheat control when the refrigerant vapor compression system has achieved stable operation. Appeal Br. 11 (Claims App.) (emphases added). Appeal 2021-001764 Application 13/822,817 3 REJECTIONS ON APPEAL 1. Claims 15–17 stand rejected under 35 U.S.C. § 112, second paragraph, as being indefinite. Final Act. 2. 2. Claims 1, 3, 5, 8, 9–11, and 15–17 stand rejected under 35 U.S.C. § 103(a) as being unpatentable over Matsuoka (US 4,807,445; Feb. 28, 1989), Nonaka (JPH 10160273 A; June 19, 1998), and Doi (US 2005/0150240 A1; July 14, 2005). Final Act. 3–7. 3. Claim 2 stands rejected under § 103(a) as being unpatentable over Matsuoka, Nonaka, Doi, and Lee (US 6,951,116 B2; Oct. 4, 2005). Final Act. 8. 4. Claims 6 and 7 stand rejected under § 103(a) as being unpatentable over Matsuoka, Nonaka, Doi, and Alsenz (US 4,651,535; Mar. 24, 1987). Final Act. 8–9. 5. Claims 12 and 13 stand rejected under § 103(a) as being unpatentable over Matsuoka, Nonaka, Doi, Lee, and Goto (JPH08200843A; Aug. 6, 1996). Final Act. 9. 6. Claim 18 stands rejected under § 103(a) as being unpatentable over Matsuoka, Nonaka, Doi, and Alsenz. Final Act. 9. 7. Claim 19 stands rejected under § 103(a) as being unpatentable over Matsuoka, Nonaka, Doi, Alsenz, and Widdowson (US 3,715,894; Feb. 13, 1973). Final Act. 9. 8. Claim 20 stands rejected under § 103(a) as being unpatentable over Matsuoka, Nonaka, Doi, Alsenz, and Ludwig (US 2006/0042282 A1; Mar. 2, 2006). Final Act. 9. Appeal 2021-001764 Application 13/822,817 4 ANALYSIS A. Indefiniteness Appellant does not appeal the Examiner’s indefiniteness rejection of claims 15–17 under 35 U.S.C. § 112, second paragraph. See Appeal Br. 3 n.1. Thus, we summarily sustain the Examiner’s indefiniteness rejection. See In re Berger, 279 F.3d 975 (Fed. Cir. 2002) (upholding the Board’s affirmance of an uncontested rejection because appellant had waived the right to contest the rejection by not presenting arguments on appeal to the Board). B. Obviousness 1. Claims 1, 3, 5, 8, 9–11 and 15–17 We begin with claim 1. The Examiner finds that Matsuoka discloses substantially all the elements of the refrigeration system as claimed, including compressor 10, expansion valve 16, ambient temperature sensor 30, and controller 22 operatively coupled to the expansion valve and the temperature sensor. Final Act. 3 (citing Matsuoka, Abstract, Figs. 1, 14). The Examiner further finds that Matsuoka’s controller includes the two control modes as claimed, namely, “a superheat control” and “a transient operation control.” Id. at 4–5 (citing Matsuoka, 8:25–35, 8:46–60, Fig. 3, Fig. 11 (steps 314–316)). The Examiner acknowledges, however, that Matsuoka omits the claim elements of “a compressor speed sensor” and “an evaporator outlet pressure sensor” coupled to the controller for also activating the expansion valve. Id. at 4–5. For the first missing element, the Examiner finds that Nonaka teaches a compressor speed sensor 9 operatively connected to a controller 10 for activating an expansion valve 4. Id. at 4 (citing Nonaka, Abstract, ¶ 8, Appeal 2021-001764 Application 13/822,817 5 Fig. 1). According to the Examiner, Nonaka’s controller includes a superheat control that establishes a desired superheat value (optimum SH value) based on compressor speed N for controlling and readjusting the expansion valve position “based on the temperature discharge adjustment caused by a change in the compressor speed after the transient change in compressor outlet enthalpy.” Id. (citing Nonaka, ¶¶ 11, 14, 22, 25, Fig. 4). From there, the Examiner concludes that one skilled in the art would have deemed it obvious to reconfigure the controller of Matsuoka so as to activate the system’s expansion valve “based on the compressor speed as taught by Nonaka in order to attain higher efficiency throughout various operations of the refrigeration cycle as the efficiency of the compressor depends upon the rotation speed of the compressor.” Id. at 4–5. For the second missing element, the Examiner finds that Doi teaches an evaporator outlet pressure sensor 159B coupled to a controller 171 for activating an expansion valve. Id. at 5 (citing Doi, Abstract, ¶¶ 38, 45, Fig. 2). Doi’s controller calculates a transient system change based on the sensed data for the purpose of resetting the opening degree of the expansion valve “to get a superheat value of at least 5 degree [Celsius].” Id. (citing Doi ¶¶ 45, 48–49, Figs. 3, 4). Based on those findings, the Examiner concludes that it would have been obvious to one skilled in the art to modify the expansion valve activation in Matsuoka’s system to establish the superheat value based on evaporator outlet pressure . . . as taught by Doi in order to control the degree of superheat at the outlet of the evaporator to attain positive superheat at the evaporator outlet and prevent liquid refrigerant from entering the compressor and in order to allow the expansion valve to achieve the desired position and allow the refrigeration system to circulate the refrigerant at the desired Appeal 2021-001764 Application 13/822,817 6 expansion valve position before making a change for the change in operational state of the system. Id. Appellant disputes only the Examiner’s finding that Matsuoka discloses the two control modes required by claim 1, namely, “a superheat control” and “a transient operation control.” Appeal Br. 4–7 (emphasis omitted). Appellant does not dispute the Examiner’s findings and conclusions with respect to Nonaka and Doi. Rather, according to Appellant, the Examiner errs in finding that Matsuoka’s Figure 3 depicts a transient operation control for “the period of time from [point] 0 to point c” and a super heat control for “the period of time after point c.” Id. at 5. Appellant argues that Figure 3 actually supports a different finding—that Matsuoka uses “the same control process . . from time 0 onward” wherein “only an integral variable, Ti, is altered to accommodate for the transient superheat from point to point c,” regardless of “whether the system is experiencing transient superheat or stable superheat.” Id. at 5–6 (quoting and discussing Matsuoka, 8:22–45, Fig. 3). Or, as Appellant also puts it, “Matsuoka discloses a single PID control mode with an integral variable, Ti, that varies based on whether the superheat is transient or stable.” Id. at 7. “Varying the integral variable, Ti,” Appellant asserts, “does not correspond to the language of claim 1.” Id. at 6. According to Appellant, “reducing the integral variable, Ti, does not correspond to the claimed ‘transient operation control that, upon detecting a transient system change, establishes a predicted expansion valve position based on the sensed transient system change . . . .’” Id. at 7. Appeal 2021-001764 Application 13/822,817 7 We disagree. To begin, we note that Appellant does not dispute that Matsuoka’s controller includes a “superheat control” mode as claimed. See Appeal Br. 5–7. Instead, Appellant’s argument focuses on the claimed “transient operation control,” which performs the following steps: establishes a predicted expansion valve position based on the sensed transient system change, waits for a waiting period, determines if the . . . system has achieved stable operation, resets the predicted expansion valve position when the . . . system has not achieved stable operation[,] and reverts to the superheat control when the . . . system has achieved stable operation. See id. at 6–7 (arguing that “[i]n Matsuoka, reducing the integral variable, Ti, does not correspond to the claimed ‘transient operation control that . . . .”). Appellant does not apprise us of error in the Examiner’s finding that Matsuoka’s controller employs a “superheat control” and a “transient operation control” in the manner claimed. See Ans. 4. As noted by the Examiner, Matsuoka’s Figure 3 discloses that the control circuit operates in a superheat control mode once the system achieves a stable state (meaning after point c) and operates in a transient operation control mode while attempting to reach a stable state (meaning from point 0 to point c). See Matsuoka, 8:22–45, 8:50–60. In other words, point c serves as a reference point where Matsuoka’s controller changes from a transient control mode to a superheat control mode in the process of controlling the degree of opening of the expansion valve. Indeed, in describing that process, Matsuoka refers Appeal 2021-001764 Application 13/822,817 8 repeatedly to a “PID[2] control” that monitors the elapsed time after the start of the system and “[w]hen the elapsed time reaches a reference time, a control constant . . . of the PID control is changed from a first value to a second value.” Matsuoka, 2:46–56 (emphasis added). According to Matsuoka, “the elapsed time before a change of control constant is not fixed,” but depends on the “number of times” that “the actual degree of superheat alternately overshoots and undershoots a desired degree of superheat” (also known as “crossings”). Id. at 2:57–3:3. Those passages, in our view, support a dual mode operation where the control constant has a start value during the unfixed period of time the superheat overshoots and undershoots a desired objective (transient superheat operation) before the control constant changes to a steady state value upon the superheat reaching the desired objective (stable superheat operation). With regard to Appellant’s argument that “reducing the integral variable, Ti, does not correspond to the claimed ‘transient operation control that, upon detecting a transient system change, establishes a predicted expansion valve position based on the sensed transient system change . . . .,’” it is noted that Appellant does not adequately address the Examiner’s position in this regard. The Examiner cited Figure 11, step 314, and variable Dtn as meeting this limitation. Final Act. 3. As the Examiner additionally notes, Matsuoka’s Figure 11 illustrates that the degree of opening the expansion 2 A PID control is defined as a process that “includes proportional, integral, and derivative control components.” Matsuoka, 1:43–45; see also id. at 2:46–48 (“The degree of opening of the expansion valve is controlled by a proportional plus integral plus derivative (PID) control.”). Appeal 2021-001764 Application 13/822,817 9 valve, referred to as “Dtn,” is determined on the basis of variations in the value of Ti (which Appellant acknowledges varies depending on the transient or stable state, i.e., before and after point c in Matsuoka Figure 3), and also on the basis of variations in the value of other variables, such as Kp, N, and Theta. See Ans. 4–6 (citing Matsuoka, Fig. 11, steps 301, 314-316); see also Matsuoka, 7:25–44 (defining “optimum PID control constants” for calculating Dtn as including Kp, Ti, and Td variables). Variations in the values of those variables, the Examiner explains, indicate the use of “different control methods” as supported by Matsuoka’s Figures 3 and 4, which show “variations in the value of Ti from Tis to Tio after point c,” whereas “Ti = Tis before point c.” Ans. 6; see also Matsuoka, 8:31–37 (describing same). Matsuoka’s Figure 5 similarly illustrates a variation in Kp before and after point c. See Matsuoka, 8:41–44 (describing the variations depicted in Fig. 5). Thus, the Examiner determines there were not only “different control methods,” but additionally “control processes for determining [the] degree of opening of the expansion valve (DTn) before point c.” Ans. 6. Other than a naked assertion that Matsuoka lacks this aspect of the claimed subject matter, Appellant provides no arguments as to why this process in Matsuoka, as relied upon by the Examiner, is not reasonably regarded as falling within the claim language, “upon detecting a transient system change, establishes a predicted expansion valve position based on the sensed transient system change.” The Examiner’s position in this regard stands essentially uncontroverted for purposes of this appeal. The remaining language of the claim quoted by Appellant, “waits for a waiting period . . .” seems clearly met by the Examiner’s reference to the waiting interval and looped operation depicted in Figure 11. Final Act. 3–4. Appeal 2021-001764 Application 13/822,817 10 Again, Appellant does not point out with specificity any supposed errors in the Examiner’s determinations in these regards. In the end, the Examiner provides sufficient evidentiary support and explanation for finding that Matsuoka discloses the two control modes as claimed. See Final Act. 3–4; Ans. 4–6. Moreover, the Examiner persuasively rebuts Appellant’s argument that Matsuoka does not perform transient operation control in the claimed manner. See Ans. 6. Appellant provides no rebuttal to the contrary. Without more from Appellant, we are not apprised of error in the Examiner’s findings with respect to Matsuoka’s two control modes for activating the expansion valve, and because Appellant does not further dispute the Examiner’s findings and conclusions with respect to the combined teachings of Matsuoka, Nonaka, and Doi, we sustain the obviousness rejection of claim 1. We also sustain the rejection of dependent claims 3, 5, and 8, which are not argued separately and thus fall with claim 1. See 37 C.F.R. § 41.37(c)(1)(iv). Acknowledging the “similarities of claim 9 to claim 1,” Appellant relies on “the arguments advanced with respect to claim 1” while noting that “neither Nonaka nor Doi cures the deficiencies of Matsuoka.” Appeal Br. 7–8. As discussed above, we reject the notion that the Examiner’s proposed combination of Matsuoka, Nonaka, and Doi is deficient in satisfying the two control modes of claim 1. Thus, for the same reasons we sustain the rejection of claim 1, we likewise sustain the rejection of claim 9, as well as dependent claims 10, 11, and 15–17, which are not argued separately and fall with claim 9. Appeal 2021-001764 Application 13/822,817 11 2. The Remaining Claims Appellant addresses dependent claims 2, 6, 7, 12, 13, and 18–20 separately from their respective independent claims 1 and 9. See Appeal Br. 8–9. But, in contesting the rejections of claims 2, 6, and 7, Appellant states simply that those rejections “should be reversed for at least the reasons advanced with respect to claim 1.” Id. at 8–9. Likewise, in contesting the rejections of claims 12, 13, and 18–20, Appellant states simply that those rejections “should be reversed for at least the reasons advanced with respect to claim 9.” Id. at 9. As discussed above, we are not persuaded by the arguments advanced by Appellant with respect to either claim 1 or claim 9. Thus, we likewise sustain the Examiner’s obviousness rejections of dependent claims 2, 6, 7, 12, 13, and 18–20. Appeal 2021-001764 Application 13/822,817 12 CONCLUSION Claims Rejected 35 U.S.C. § Reference(s)/Basis Affirmed Reversed 15–17 112 Indefinite 15–17 1, 3, 5, 8, 9–11, 15–17 103(a) Matsuoka, Nonaka, Doi 1, 3, 5, 8, 9–11, 15–17 2 103(a) Matsuoka, Nonaka, Doi, Lee 2 6, 7 103(a) Matsuoka, Nonaka, Doi, Alsenz 6, 7 12, 13 103(a) Matsuoka, Nonaka, Doi, Lee, Goto 12, 13 18 103(a) Matsuoka, Nonaka, Doi, Alsenz 18 19 103(a) Matsuoka, Nonaka, Doi, Alsenz, Widdowson 19 20 103(a) Matsuoka, Nonaka, Doi, Alsenz, Ludwig 20 Overall Outcome 1–3, 5–13, 15–20 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)(1)(iv). AFFIRMED Copy with citationCopy as parenthetical citation