ClearSign Combustion CorporationDownload PDFPatent Trials and Appeals BoardJul 27, 20202019005331 (P.T.A.B. Jul. 27, 2020) 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. 15/091,906 04/06/2016 DOUGLAS W. KARKOW 2651-253-03 6122 134647 7590 07/27/2020 Launchpad IP, Inc. 914 164th St. SE Suite B-12 #433 Mill Creek, WA 98012 EXAMINER LAU, JASON ART UNIT PAPER NUMBER 3762 NOTIFICATION DATE DELIVERY MODE 07/27/2020 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): docket@launchpadip.com renise@launchpadip.com PTOL-90A (Rev. 04/07) UNITED STATES PATENT AND TRADEMARK OFFICE BEFORE THE PATENT TRIAL AND APPEAL BOARD Ex parte DOUGLAS W. KARKOW, JOSEPH COLANNINO, ROBERT E. BREIDENTHAL, and CHRISTOPHER A. WIKLOF Appeal 2019-005331 Application 15/091,906 Technology Center 3700 Before CHARLES N. GREENHUT, MICHAEL J. FITZPATRICK, and MICHELLE R. OSINSKI, Administrative Patent Judges. GREENHUT, Administrative Patent Judge. DECISION ON APPEAL STATEMENT OF THE CASE Pursuant to 35 U.S.C. § 134(a), Appellant1 appeals from the Examiner’s decision to reject claims 1–25. See Final Act. 1. We have jurisdiction under 35 U.S.C. § 6(b). We REVERSE. 1 We use the word Appellant to refer to “applicant” as defined in 37 C.F.R. § 1.42. Appellant identifies the real party in interest as ClearSign Combustion Corporation, having an address at 12870 Interurban Avenue South, Seattle, WA 98168. Appeal Br. 3. Appeal 2019-005331 Application 15/091,906 2 CLAIMED SUBJECT MATTER The claims are directed to a pre-mixed fuel burner with perforated flame holder. Claim 1, reproduced below, is illustrative of the claimed subject matter: 1. A combustion system, comprising: a premix chamber configured to receive an oxidant and a fuel, wherein the premix chamber is configured to provide an oxidant-fuel mixture into a chamber volume; and a perforated reaction holder positioned within the chamber volume, wherein the perforated reaction holder is displaced from the premix chamber and aligned with the premix chamber to receive the oxidant-fuel mixture; wherein the perforated reaction holder carries a combustion reaction while at least part of the oxidant-fuel mixture combusts; wherein the premix chamber is configured to receive an oxidant inlet extending at least partially into the premix chamber and a fuel inlet at least partially carried within the oxidant inlet; and wherein the oxidant inlet is terminated, inside the premix chamber, at an angle that directs incoming fuel and oxidant away from an outlet of the premix chamber and causes the fuel stream and the oxidant stream to mix in a pair of counter-rotating vortices within the premix chamber mix prior to passing through the outlet. Appeal 2019-005331 Application 15/091,906 3 REFERENCES The prior art relied upon by the Examiner is: Name Reference Date Stack US 3,155,142 Nov. 3, 1964 Wojcieson US 4,443,182 Apr. 17, 1984 Taylor US 5,326,257 July 5, 1994 Mauzey US 2004/0058290 A1 Mar. 25, 2004 Leinemann US 2006/0008755 A1 Jan. 12, 2006 Krauklis US 2006/0292510 A1 Dec. 28, 2006 Borissov US 2012/0064465 A1 Mar. 15, 2012 REJECTIONS Claim 1 is rejected under 35 U.S.C. § 103 as being unpatentable over Taylor and Borissov. Final Act. 2. Claims 1–3, 5, 6, 8, 10–13, 16, 19, 24, and 25 are rejected under 35 U.S.C. § 103 as being unpatentable over Stack, Taylor, and Borissov. Final Act. 3. Claim 4 is rejected under 35 U.S.C. § 103 as being unpatentable over Stack, Taylor, Borissov, and Krauklis. Final Act. 7. Claims 7 and 9 are rejected under 35 U.S.C. § 103 as being unpatentable over Stack, Taylor, Borissov, and Leinemann. Final Act. 7. Claims 14, 15,2 20, 22, and 23 are rejected under 35 U.S.C. § 103 as being unpatentable over Stack, Taylor, Borissov, and Wojcieson. Final Act. 9. 2 Even though the Examiner failed to include reference to claim 15 in the heading for this rejection (see Final Act. 9), the Examiner makes reference to this claim within the body of the rejection (see id. at 10). We consider the failure to include reference to claim 15 in the heading a typographical error, and therefore, we list claim 15 as being subject to this ground of rejection. Appeal 2019-005331 Application 15/091,906 4 Claims 17, 20, and 21 are rejected under 35 U.S.C. § 103 as being unpatentable over Stack, Taylor, Borissov, and Mauzey. Final Act. 11. Claim 18 is rejected under 35 U.S.C. § 103 as being unpatentable over Stack, Taylor, Borissov, Mauzey, and Wojcieson. Final Act. 13. OPINION A central issue in this appeal is the Examiner’s reliance on certain chambers or portions of chambers in Taylor, Borissov, and Stack as the recited “premix chamber” as recited in each of independent claims 1 and 16, the only independent claims before us. Reply Br. 2–3, 5. There does not appear to be any dispute that a “premix chamber” in this context must at the very least be associated with the mixing of fuel and oxidant. Irrespective of general or art-specific definitions, the language of claim 1 itself goes further, requiring the “fuel inlet” to be “carried within the oxidant inlet,” which itself must be “extending at least partially into,” and “terminated[] inside,” “the premix chamber,” “within” which “the fuel stream and the oxidant stream . . . mix.” Claim 1. Claim 16 makes similar requirements of the premix chamber in the contexts of the following recited method steps: receiving an oxidant in a premix chamber from an oxidant inlet extending at least partially into the premix chamber; receiving a hydrocarbon fuel into the premix chamber from a fuel inlet at least partially carried within the oxidant inlet; mixing the hydrocarbon fuel in the premix chamber, to generate an oxidant-fuel mixture . . . Taylor and Stack are similar in that, contrary to the language of claims 1 and 16, premixing of the fuel and oxidizer appears to occur at some undisclosed location. Taylor illustrates the air and fuel supply 40 Appeal 2019-005331 Application 15/091,906 5 schematically. From the schematic illustration alone, it could be argued that it is not clear if the box 40 and the line connecting box 40 to conduit 42 represent premixed, or separate streams of, fuel and air. The Examiner appears to believe the latter is a possibility based on the Examiner’s proposed modification to Taylor to replace box 40 and its associated connection line with the separate streams described in Borissov. See Ans. 17–18 (annotating Taylor Fig. 1 with what appears to be a combination of modified versions of Figures 4 and 7 of Borissov). However, as Appellant points out Taylor consistently refers to delivering a “premixed supply of air and fuel into the lower interior region 22 via conduit 42. Appeal Br. 21 (citing Taylor col. 4, ll. 6 et seq.); see also Taylor col. 4, ll. 15–16. Because the air and fuel in Taylor are mixed prior to entering plenum 48 in Taylor, it is not reasonable in this context for the Examiner to rely on plenum 48 as the recited “premix chamber.” See Final Act. 2. With respect to Stack, the Examiner’s reliance on the space defined by diffuser plate 15 on its lowermost end (when viewed in Figure 2 of Stack), feed plate 12 on its uppermost end and the internal bore of housing portion 13b, suffers from a similar shortcoming because Stack states: “A pipe 14 is suitably provided for introduction of combustible gas-air mixtures to the feed plate 12.” Stack col. 3, ll. 37-38. As Appellant points out, this passage, along with the following passage encouraging stratification prevention, strongly suggests that fuel and oxidant are mixed prior to arriving at the space the Examiner relies upon as the recited “premix chamber.” Appeal Br. 26 (citing Stack col. 3, ll. 37 et seq.). The Examiner also points to Borissov as disclosing a “premix chamber.” Final Act. 3, 4. There is nothing wrong, per se, with pointing out Appeal 2019-005331 Application 15/091,906 6 a reference teaches subject matter for which the Examiner has already cited another reference, contrary to Appellant’s suggestion. Appeal Br. 25. However, in this instance, Appellant’s confusion in understanding the precise position taken by the Examiner in the Final Action is understandable. In any case, the Examiner’s position in this regard appears to be clarified in conjunction with the annotated Taylor Figure on page 18 of the Answer mentioned above and the similar annotation of Figure 2 of Stack illustrated on page 23 of the Answer. The Examiner indicates that it is the region of Borissov’s chamber within swirler nozzle or a diverging outlet 51, referred to as cone 51 that constitutes a “premix chamber” according to claim 1 and, by implication, claim 16. Ans. 16–17. First, although not necessarily controlling, “[p]rior art references may be ‘indicative of what all those skilled in the art generally believe a certain term means . . . [and] can often help to demonstrate how a disputed term is used by those skilled in the art.’ Accordingly, the PTO’s interpretation of claim terms should not be so broad that it conflicts with the meaning given to identical terms in other patents from analogous art.” In re Cortright, 165 F.3d 1353, 1358 (Fed. Cir. 1999) (citation omitted). Here, in the embodiment relied on by the Examiner, Borissov never refers to the “upstream end” (Ans. 16) of the combustion chamber 33 itself as being a chamber. Nor does Borissov refer to a presumably relatively small region near or within nozzle or cone 51 as a chamber. Borissov was clearly aware of the word “chamber” and knew that it took some identifiable boundaries to create one as evidenced by Borissov’s reference to combustion chamber 433 being separated by diaphragm 477 into a “main combustion chamber 433a and a Appeal 2019-005331 Application 15/091,906 7 pre-chamber 433b” (emphasis added) when describing the alternate embodiment depicted in Figure 12 of Borissov.3 Borissov para. 104. Even assuming that the region within cone 51 is reasonably regarded as a chamber, there is no dispute that the “pre” in “premix” refers to mixing that occurs before combustion. Borissov neither illustrates nor discloses the precise location of ignition in the embodiment depicted in Figures 1–8. However, Borissov discloses an “igniter (not shown in the Figures for this embodiment) positioned proximate the 10 local circulation region LCR and/or the fuel nozzle 49 to initiate combustion.” Borissov para. 65. Nozzle 49 is depicted in Figures 1 and 4 of Borissov on the upstream end of the region within cone 51 which the Examiner relies on as being the “premix chamber.” Of course, if combustion occurs proximate nozzle 49 sufficiently upstream of cone 51, there is clearly little or no premixing of fuel and oxidant within cone 51. The Examiner posits that Borissov’s mention of a possible igniter location as proximate local circulation region LCR places the igniter at the downstream end of cone 51. Ans. 16–17. However, even if this were the case, it is not clear from Borissov’s disclosure what level and what type of premixing, if any, would occur in this region within cone 51. In order to arrive at the counter-rotating vortices required to exist within the premix chamber according to claims 1 and 16, the Examiner relies on the 3 The Examiner does not place any reliance on the embodiment of Borissov depicted in Figure 12 in support of the Examiner’s grounds for rejecting the claims on appeal. Accordingly, neither will we. See 37 C.F.R. § 41.50(a)(1) (“The Board, in its decision, may affirm or reverse the decision of the examiner in whole or in part on the grounds and on the claims specified by the examiner.”) (emphasis added). Although the Board is authorized to reject claims under 37 C.F.R. § 41.50(b), no inference should be drawn when the Board elects not to do so. See MPEP § 1213.02. Appeal 2019-005331 Application 15/091,906 8 flow pattern that exists outside of the Examiner’s own delineation of the extents of the premix chamber. See Ans. 18 (illustrating Borissov’s circulation region incorporated into Taylor). Borissov indicates that “counterflow CF” is of “hot flue gases directed back into the throat 57.” Borissov para. 70. We understand this to mean that the counterflow in Borissov is mainly or entirely comprised of the gaseous products of combustion as opposed to the fuel and oxidant reactants. Appeal Br. 24. Thus, even under the Examiner’s proposed interpretation of the premix chamber in Borissov, the Examiner fails to demonstrate how the proposed combination would yield the claimed subject matter. Reply Br. 2. Moreover, it is not clear on the record before us what benefit, if any, could be expected by extracting the elements of Borissov’s combustion region and placing them upstream of the combustion regions in either Taylor or Stack. See Ans. 18, 23; Appeal Br. 27–28. The Examiner does not explain and it is not apparent why Borissov’s teachings relating to the manner in which combustion occurs in Borissov’s burner would be relevant to the particular regions in Taylor and Stack in which the Examiner proposed to incorporate elements from Borissov. CONCLUSION For the foregoing reasons, the Examiner’s rejections are REVERSED. Appeal 2019-005331 Application 15/091,906 9 DECISION SUMMARY Claims Rejected 35 U.S.C. § Reference(s)/Basis Affirmed Reversed 1 103 Taylor, Borissov 1 1–3, 5, 6, 8, 10–13, 16, 19, 24, 25 103 Stack, Taylor, Borissov 1–3, 5, 6, 8, 10–13, 16, 19, 24, 25 4 103 Stack, Taylor, Borissov, Krauklis 4 7, 9 103 Stack, Taylor, Borissov, Leinemann 7, 9 14, 15, 20, 22, 23 103 Stack, Taylor, Borissov, Wojcieson 14, 15, 20, 22, 23 17, 20, 21 103 Stack, Taylor, Borissov, Mauzey 17, 20, 21 18 103 Stack, Taylor, Borissov, Mauzey, Wojcieson 18 Overall Outcome 1–25 REVERSED Copy with citationCopy as parenthetical citation