Ex Parte Guillard et alDownload PDFPatent Trial and Appeal BoardJun 28, 201310580797 (P.T.A.B. Jun. 28, 2013) 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. 10/580,797 05/26/2006 Alain Guillard Serie 6423 7256 7590 06/28/2013 Linda K Sussell Air Liquide Intellectual Property Department 2700 Post Oak Blvd Ste 1800 Houston, TX 77056 EXAMINER HAMO, PATRICK ART UNIT PAPER NUMBER 3746 MAIL DATE DELIVERY MODE 06/28/2013 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 ALAIN GUILLARD and FRANCOIS-XAVIER LAMANT ____________ Appeal 2011-007137 Application 10/580,797 Technology Center 3700 ____________ Before LINDA E. HORNER, PHILLIP J. KAUFFMAN, and BARRY L. GROSSMAN, Administrative Patent Judges. HORNER, Administrative Patent Judge. DECISION ON APPEAL STATEMENT OF THE CASE Alain Guillard and Francois-Xavier Lamant (Appellants) seek our review under 35 U.S.C. § 134 of the Examiner’s decision rejecting claims 13-20. Claims 1-12 and 21 are canceled, and claim 22 is pending and not rejected. We have jurisdiction under 35 U.S.C. § 6(b). We AFFIRM. Appeal 2011-007137 Application 10/580,797 2 THE INVENTION Appellants’ claimed invention “relates to a gas compressor and to a unit for separating a gas mixture incorporating such a compressor.” Spec. 1, ll. 7-9. Claim 13, reproduced below, is illustrative of the subject matter on appeal. 13. A gas compressor having n stages connected in series, where n is equal to at least 3, each stage being followed by a cooler wherein at least two coolers have different pressure drops for the compressed gas, the cooler having the lower pressure drop being upstream of that having the higher pressure drop. THE EVIDENCE The Examiner relies upon the following evidence: Barchas US 5,082,481 Jan. 21, 1992 Wong US 6,685,903 B2 Feb. 3, 2004 Kaellis US 6,808,017 B1 Oct. 26, 2004 THE REJECTIONS Appellants seek review of the following rejections: 1. Claims 13-19 under 35 U.S.C. § 103(a) as unpatentable over Barchas and Kaellis; and 2. Claim 20 under 35 U.S.C. § 103(a) as unpatentable over Barchas, Kaellis, and Wong. ANALYSIS Appellants argue the claims subject to the first ground of rejection as a group, and rely on the same arguments raised in rebuttal of the first ground of rejection as the basis for reversal of the second ground of rejection of Appeal 2011-007137 Application 10/580,797 3 dependent claim 20. Br. 11. We select claim 13 as representative for the first ground of rejection. See 37 C.F.R. § 41.37(c)(1)(vii) (2011). Since Appellants present no additional arguments in rebuttal of the second ground of rejection, the outcome of this appeal turns on our review of the rejection of claim 13 based on Barchas and Kaellis. The Examiner found that Barchas discloses a gas compression system comprising five stages (12, 18, 24, 30, 36), with each stage followed by a cooler system (14, 20, 26, 32, 48/50/52, respectively). Ans. 4. The Examiner found that while “Barchas does not explicitly disclose that the pressure drop is higher through the last set of coolers than the first[,]” each cooler of Barchas is described as operating at a temperature between 80 and 120 degrees F, and therefore “if each cooler is considered to be the same make and model, the pressure drop through the cooler system after the final stage comprising three of the coolers of the preceding stages would be higher than the pressure drop through just one cooler.” Id. at 4, 7. The Examiner found that “one of ordinary skill in the art would recognize that the cooler (48, 50, 52) in the final stage would result in the largest temperature drop in the system, thus resulting in the largest pressure drop across the coolers (48, 50, 52).” Id. at 7; see also id. at 4. The Examiner additionally found that “Kaellis teaches that it is well known in the art that cooler design is a matter of trade off between pressure drop and cooling efficiency.” Id. at 7. The Examiner stated that “this teaching in combination with the teaching of Barchas that there are more coolers after the final stage would lead one of ordinary skill in the art to the Appeal 2011-007137 Application 10/580,797 4 conclusion that it was obvious that Barchas intended greater cooling and therefore a higher pressure drop through the final stages, and that is why the invention provided three cooler stages whereas only one cooler stage was provided after each previous compressor stage.” Id. at 7-8. The Examiner further stated that “the higher pressure would accommodate a higher pressure drop, so that one skilled in the art would be able to trade off some pressure drop for cooler efficiency, as taught by Kaellis” and “how much pressure drop is sacrificed is a design choice based on the desired cooler efficiency.” Id. at 8. Appellants respond “[i]t is indeed unclear why the draftsman for the figures in Barchas chose to indicate multiple after coolers, but there is absolutely no indication that the three coolers imply triple the pressure drop of the single coolers upstream.” Br. 12. Appellants further respond: Given the basic nature of the invention in Barchas (i.e. to reduce the overall refrigeration requirements of the separation of low-boiling components from cracking effluent), the higher the pressure, the better this goal is achieved. The last thing that the designer of this system would wish is to unnecessarily reduce this expensive pressure gain through heat exchangers, for which a reasonable reduction in pressure drop is moderately inexpensive to achieve. Id. Appellants’ argument appears to suggest that the only concern in Barchas’s system is the pressure of the effluent when it enters the low temperature separation system (the refrigeration step). Appellants’ argument fails to acknowledge that in Barchas there is also a need to cool in the final Appeal 2011-007137 Application 10/580,797 5 stage prior to passing the effluent to the rest of the system, and that Barchas shows not one, but three, coolers in the final stage. Barchas discloses: Prior to passing of the cracked effluent to the cooling or refrigeration step to separate lower-boiling components, and also between compression stages if multiple compression stages are employed, cooling of the cracked effluent may take place through passing of the cracking effluent through one or more coolers, which may be operated at temperatures of from about 70° F. to about 150° F., preferably from about 80° F. to about 120° F. Barchas, col. 3, ll. 36-46. We find reasonable the Examiner’s determination that Barchas’s disclosure of three coolers after the fifth stage, as compared to the single intercooler after each of the first through fourth stages, suggests, or at least would render obvious, to one of ordinary skill in the art greater cooling in the fifth stage than in any of the first stage. According to the Examiner’s finding (Ans. 7), if a larger temperature drop occurs in the fifth stage as compared to, for example, the first stage, this larger temperature drop would result in a larger pressure drop in this fifth (downstream) stage as compared to the first (upstream) stage. Even if we assume as true Appellants’ assertion that preserving the pressure gain may reduce the refrigeration requirements during the separation of low-boiling components from cracking effluent during the refrigeration step, Barchas nonetheless teaches cooling the cracked effluent before it is passed to this refrigeration step, thus recognizing implicitly that some loss of the pressure gain would be had during this cooling of the Appeal 2011-007137 Application 10/580,797 6 cracked effluent. Barchas addresses the reduction of the refrigeration requirements of the refrigeration step not by minimization of loss of pressure gain during cooling, but by removing some of the hydrogen prior to the refrigeration step by passing the cracked effluent through one or more membrane stages. Barchas, col. 5, ll. 36-58. We agree with the Examiner that the amount of cooling that takes place in the final stage is an obvious design consideration that balances the tradeoff between the requirement for cooling the effluent prior to passing it to the remaining portions of the system versus the loss in pressure gain that occurs as a result of cooling. See Kaellis, col. 1, ll. 29-35. Our reviewing court has acknowledged that “[t]he fact that the motivating benefit comes at the expense of another benefit, however, should not nullify its use as a basis to modify the disclosure of one reference with the teachings of another. Instead, the benefits, both lost and gained, should be weighed against one another.” Winner Int’l Royalty Corp. v. Wang, 202 F.3d 1340, 1349 n.8 (Fed. Cir. 2000) (discussing tradeoff between using a more secure dead-bolt and using a more convenient ratcheting mechanism). The relative advantages and disadvantages to providing more cooling, and thus a higher pressure drop, at the last stage of Barchas amounts to an engineering tradeoff – a decision well within the level of ordinary skilled artisans. For the reasons discussed supra, Appellants have failed to persuade us of error in the Examiner’s determination that Barchas’s disclosure of three coolers during the final stage as compared to a single cooler during each of the first four stages, in combination with the teaching of Kaellis, renders Appeal 2011-007137 Application 10/580,797 7 obvious the claimed gas compressor with a cooler having a lower pressure drop being upstream of a cooler having a higher pressure drop, as called for in claim 13. DECISION We AFFIRM the decision of the Examiner to reject claims 13-20. No time period for taking any subsequent action in connection with this appeal may be extended under 37 C.F.R. § 1.136(a). See 37 C.F.R. § 1.136(a)(1)(iv). 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