Andreas Stihl AG & Co. KGDownload PDFPatent Trials and Appeals BoardJul 27, 20212020006287 (P.T.A.B. Jul. 27, 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. 15/261,374 09/09/2016 Jan-Philipp Banzhaf A 95581 2605 47988 7590 07/27/2021 WALTER OTTESEN, P.A. PO BOX 4026 GAITHERSBURG, MD 20885-4026 EXAMINER CAMPBELL, JOSHUA A ART UNIT PAPER NUMBER 3747 MAIL DATE DELIVERY MODE 07/27/2021 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 JAN-PHILIPP BANZHAF and KARSTEN SCHMIDT ____________ Appeal 2020-006287 Application 15/261,374 Technology Center 3700 ____________ Before CHARLES N. GREENHUT, GEORGE R. HOSKINS, and MICHAEL L. WOODS, Administrative Patent Judges. HOSKINS, Administrative Patent Judge. DECISION ON APPEAL Pursuant to 35 U.S.C. § 134(a), Appellant1 appeals from the Examiner’s decision rejecting claims 1, 22, and 21 in this application under 35 U.S.C. § 103 as unpatentable over Dangelmaier (US 2013/0199812 A1, published Aug. 8, 2013), Bahner (US 2009/0012699 A1, published Jan. 8, 2009), and Ostojic (US 2011/0000462 A1, published Jan. 6, 2011). We REVERSE. 1 We use the word “Appellant” to refer to “applicant” as defined in 37 C.F.R. § 1.42. The Appeal Brief identifies Andreas Stihl AG & Co. KG, and both of the named inventors, as the real parties in interest. Appeal Br. 2. 2 The Office Action on appeal is not clear regarding the status of claim 2. It acknowledges claim 2 as a pending claim (Non-Final Act., dated Sept. 18, 2019, at 1), but does not thereafter address claim 2 (id. at 2–5). The Appeal Brief does not address this uncertainty. See Appeal Br. 1, 4, 17. The Answer adds claim 2 to the rejection, so we include it here. See Ans. 3–5. Appeal 2020-006287 Application 15/261,374 2 CLAIMED SUBJECT MATTER Claims 1 and 21 are the independent claims on appeal. Claim 1 illustratively recites (see Appeal Br. 18–19 (Claims App.)): l. A method for operating a work apparatus having a combustion engine including a combustion chamber, a piston delimiting the combustion chamber, a spark plug, an ignition device configured to trigger an ignition spark at the spark plug so as to ignite a fuel/air mixture in the combustion chamber, the ignition device being configured to trigger an ignition spark at the spark plug at an ignition time point (ZZP) in dependence upon the rotational position of the piston, a work tool, a crankshaft configured to drive the work tool, a centrifugal clutch arranged between the crankshaft and the work tool, the method comprising the steps of: monitoring the rotational speed (n) of the combustion engine; advancing the ignition time point (ZZP) when the following sequentially occurring conditions are satisfied: i. a rich fuel/air mixture is supplied to the combustion chamber, ii. the rotational speed (n) lies in a predetermined rotational speed range (nmin; nmax) within a predetermined time period (ΔT), wherein the predetermined rotational speed range (nmin; nmax) is between 3,000 l/min and 5,000 l/min[3], and, iii. the rotational speed (n) of the combustion engine drops off to below a rotational speed limit value (nG) after the conditions (i) and (ii) are satisfied, so that, after the conditions (i), (ii) and (iii) are fulfilled, a stopping of the combustion engine is prevented as a result of the advancing of the ignition time point (ZZP). 3 The Examiner notes “[t]he units of ‘l/min’ appears to be a typographical error because liters per minute is a measure of volumetric flow rate instead of rotational speed,” and interprets claim 1 to recite “the rotational speed range is between 3,000 and 5,000 revolutions per minute.” Ans. 7 (citing Spec. 8:10–15). Appeal 2020-006287 Application 15/261,374 3 OPINION A. Claims 1 and 2 The Examiner finds Bahner discloses, as recited in claim 1, a method comprising “monitoring the rotational speed (n) of [a] combustion engine,” and “advancing the ignition time point (ZZP) when” a portion of the claimed conditions (ii) and (iii) is satisfied. See Non-Final Act. 3–4; Ans. 3–4. In particular, the Examiner finds Bahner discloses advancing the ignition time point “when . . . ii. the rotational speed (n) lies in a predetermined rotational speed range (nmin; nmax) within a predetermined time period (ΔT),” as required by claim 1. Appeal Br. 18 (Claims App., claim 1, lines 13–23); see Non-Final Act. 3–4 (citing Bahner, Fig. 4, ¶¶ 27, 32, 42); Ans. 4. The Examiner does not rely on either Dangelmaier or Ostojic in relation to this claim limitation. See Non-Final Act. 3–4; Ans. 3–5. We conclude a preponderance of the evidence does not support the Examiner’s finding that Bahner discloses advancing the ignition time point when the foregoing portion of condition (ii) in claim 1 is satisfied, so we cannot sustain the rejection on appeal. First, we summarize Bahner’s disclosure. Then, we consider the Examiner’s findings. 1. Summary of Bahner Figure 2 of Bahner4 is reproduced on the next page: 4 The Examiner also cites Figure 4 of Bahner, which illustrates a more complicated version of Figure 2. See, e.g., Bahner ¶¶ 38–41. Figure 2 is representative of both Figures as to condition (ii) of claim 1, so we focus on Figure 2 to simplify our discussion. Appeal 2020-006287 Application 15/261,374 4 Figure 2 “shows an ignition map that provides the ignition timing as a function of engine speed.” Bahner ¶ 20. Accordingly, the horizontal axis represents the engine’s rotational speed “n,” and the vertical axis “provides the ignition timing IT as a function of the engine speed.” Id. ¶ 30. The vertical axis origin corresponds to “ignition timing IT at the top dead center of the piston,” so “[v]alues that are higher and farther up on the [vertical] axis . . . indicate an advancement of the ignition timing IT (to earlier timing).” Id. ¶ 30 (emphases added). Thus, where Appellant’s claim 1 recites “advancing the ignition time point” (Appeal Br. 18 (Claims App., claim 1, line 13)), this corresponds to moving higher along the vertical axis in Bahner’s Figure 2 to earlier timing. Appeal 2020-006287 Application 15/261,374 5 Bahner provides two different ignition timing lines in Figure 2 for correlating engine speed n to ignition timing IT. A first characteristic line 24 is used during a “starting operation” of the engine, for engine speeds between nStart,min and nStart,max. Bahner ¶¶ 31–32. A second characteristic line 25, including descending branch 26, is thereafter used during “normal operation” of the engine, for all engine speeds. Id. In other words, for engine speeds between nStart,min and nStart,max, “each engine speed n has two ignition timings correlated therewith, i.e. a first ignition timing on the characteristic line 24 for the starting operation and a second ignition timing on the characteristic line 25 [including branch 26] for normal (regular) operation.” Id. ¶ 31. Switching between the first and second characteristic lines “can be realized based on one of several switching conditions.” Id. ¶ 42. Bahner discloses three such conditions, which may be used alone, or in any combination. Id. These conditions are: (1) “completion of a predetermined number of engine cycles”; (2) “the engine speed n must have surpassed the switching engine speed nswitch illustrated in FIG. 2”; and (3) “a predetermined number of combustions has taken place.” Id. 2. The Examiner’s Findings Comparing Bahner with Claim 1 The Examiner finds Bahner discloses the “predetermined rotational speed range (nmin; nmax)” of condition (ii) in claim 1 because Bahner’s Figure 2 illustrates a “speed range . . . where the speed is above the Nswitch threshold.” Non-Final Act. 3; Ans. 4. The Examiner further finds Bahner discloses that the engine’s speed lies in that speed range “within a predetermined time period (ΔT)” as claimed, because “[t]his must occur for Appeal 2020-006287 Application 15/261,374 6 a predetermined period of time/combustion cycles.” Non-Final Act. 3 (citing Bahner ¶ 42); Ans. 4. Appellant asserts “The engine speed nswitch set forth in paragraph [0042] of Bahner . . . is the basis of a completely different operating principle” than the method of claim 1, so the Examiner errs in finding “the same switchover conditions are present in Bahner” and in claim 1. Appeal Br. 12. Upon review of the foregoing, we discern two difficulties with the Examiner’s reliance on Bahner in relation to condition (ii) of claim 1. First, the claim requires a “predetermined rotational speed range (nmin; nmax)” (emphasis added) — that is, a range with a minimum value (nmin) and a maximum value (nmax). See also Spec. 8:5–17 (“[I]t is monitored in a first element 50 [of Appellant’s Figure 4] whether the rotational speed (n) is within a rotational speed range which is determined by the minimum rotational speed nmin and the maximum rotational speed nmax.”). The Examiner’s findings point to nswitch in Bahner as the minimum value of the range, but do not point to any corresponding maximum value. As described in Bahner, nswitch corresponds to a minimum engine speed for the ignition time point control to switch from first characteristic line 24 to second characteristic line 25 (including branch 26). Bahner ¶ 42. The Bahner disclosures cited by the Examiner do not identify any maximum value of a range that might correspond to nswitch as a minimum value. See Bahner ¶¶ 27, 32, 42. Bahner does discuss how nStart,min and nStart,max are the minimum and maximum values of an engine speed range where first characteristic line 24 may be applied to set the ignition time point (id. ¶¶ 31– 32), but we find no disclosure of nStart,max being used as the maximum value of a range with nswitch being the minimum value. Appeal 2020-006287 Application 15/261,374 7 Second, the Bahner disclosures cited by the Examiner do not reflect advancing the ignition time point when the engine speed remains above nswitch “within a predetermined time period (ΔT),” as recited in condition (ii) of claim 1. See Bahner ¶¶ 27, 32, 42. The Examiner here relies especially on paragraph 42 of Bahner. Non-Final Act. 3 (citing Bahner ¶ 42). But, paragraph 42 refers to “the engine speed n [surpassing] the switching engine speed nswitch” as a different switching condition than “completion of a predetermined number of engine cycles” and “a predetermined number of combustions [taking] place.” Bahner ¶ 42. We find no disclosure of the engine speed n needing to surpass nswitch for any particular amount of time, whether measured in conventional units of time such as seconds, or other units of time such as a number of engine cycles or combustions. Id. In particular, there is no suggestion in Bahner that the counting of engine cycles or combustions begins when the engine speed n surpasses nswitch, such that Bahner might determine the engine speed n lies in a predetermined range with a minimum value of nswitch for a predetermined time period. Id. For the foregoing reasons, we do not sustain the rejection of claim 1 and its dependent claim 2 as having been obvious over Dangelmaier, Bahner, and Ostojic. 3. Claim 21 Claim 21 like claim 1 recites “advancing the ignition time point (ZZP when . . . ii. the rotational speed (n) lies in a predetermined rotational speed range (nmin; nmax) within a predetermined time period (ΔT).” Appeal Br. 19–20 (Claims App.). The Examiner relies on Bahner as disclosing this subject matter in claim 21. See Non-Final Act. 4 (“With regards to claim 21, the claim is commensurate in scope with claim[] 1 and is rejected for the Appeal 2020-006287 Application 15/261,374 8 same reasons as set forth above.”); Ans. 5 (same). Thus, for the reasons provided above, we do not sustain the rejection of claim 21 as having been obvious over Dangelmaier, Bahner, and Ostojic. SUMMARY OF DECISION In summary, we reverse the Examiner’s rejection as to all claims 1, 2, and 21, as set forth in this table: Claims Rejected 35 U.S.C. § References Affirmed Reversed 1, 2, 21 103 Dangelmaier, Bahner, Ostojic 1, 2, 21 REVERSED Copy with citationCopy as parenthetical citation