Prosecution Insights
Last updated: April 19, 2026
Application No. 18/283,570

Spheroidal Graphite Cast Iron, Method for Manufacturing Spheroidal Graphite Cast Iron, and Spheroidizing Treatment Agent

Non-Final OA §103
Filed
Sep 22, 2023
Examiner
KESSLER, CHRISTOPHER S
Art Unit
1759
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Kuwana Metals Ltd.
OA Round
1 (Non-Final)
59%
Grant Probability
Moderate
1-2
OA Rounds
3y 10m
To Grant
74%
With Interview

Examiner Intelligence

Grants 59% of resolved cases
59%
Career Allow Rate
465 granted / 783 resolved
-5.6% vs TC avg
Moderate +15% lift
Without
With
+15.0%
Interview Lift
resolved cases with interview
Typical timeline
3y 10m
Avg Prosecution
61 currently pending
Career history
844
Total Applications
across all art units

Statute-Specific Performance

§101
1.2%
-38.8% vs TC avg
§103
45.2%
+5.2% vs TC avg
§102
16.2%
-23.8% vs TC avg
§112
27.4%
-12.6% vs TC avg
Black line = Tech Center average estimate • Based on career data from 783 resolved cases

Office Action

§103
DETAILED ACTION Notice of Pre-AIA or AIA Status The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA . Election/Restrictions Applicant’s election of group I in the reply filed on 13 February 2026 is acknowledged. Because applicant did not distinctly and specifically point out the supposed errors in the restriction requirement, the election has been treated as an election without traverse (MPEP § 818.01(a)). Claims 5-11 and 15-18 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 13 February 2026. Priority Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55. Drawings The drawings were received on 22 September 2023. These drawings are accepted. Claim Rejections - 35 USC § 103 The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action: A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made. Claim(s) 1-3 and 12 is/are rejected under 35 U.S.C. 103 as being unpatentable over US 20160053351 A1 (hereinafter “Fujimoto”). Regarding claim 1, Fujimoto teaches a high strength, high damping capacity graphite cast iron (see title). Fujimoto teaches a spheroidal graphite cast iron (see BRIEF SUMMARY OF THE INVENTION or Figs 3-4). Fujimoto teaches that the spheroidal graphite cast iron has a composition which overlaps the claimed composition (See claim 1). Fujimoto further specifies the amount of Ca in claim 5. Additionally, Fujimoto teaches example cast irons (see [0053]-[0056] and Tables 1-2). One such example is Example 13 (Table 1). The composition of the iron of Fujimoto is compared with the claimed iron in the chart below (values in mass %). Element Claim 1 Fujimoto claim 1 and claim 5 Fujimoto Example 13 C Si Mn P S Mg La + Ce Ca FE/impurities 2.8-3.3 2.5-4.0 0.32-0.40 0.020-0.030 0.020-0.035 0.030-0.050 0.010-0.050 0.0020-0.0050 balance 2-4 1-5 0.2-0.9 0.1 or less 0.1 or less 0.02-0.10 0.0-0.500 0.0001-0.01 balance 3.2 2.5 0.3 0.02 0.01 0.04 0.019 (0.004 Ca + Ba) balance The broad composition of the cast iron of Fujimoto overlaps the claimed composition, establishing a prima facie case of obviousness. It would have been an obvious matter to the skilled artisan at time of filing to have selected a composition in the range as claimed, because Fujimoto teaches the same utility over an overlapping range. Applicant is directed to MPEP 2144.05. In the alternative, Fujimoto Example 13 differs from what is claimed in that the Mn is 0.3 instead of 0.32-0.40, and that the amount of S is 0.01 instead of 0.020-0.035. Fujimoto teaches a functional amount of S is up to 0.1 % (see [0045]), and a functional amount of Mn is 0.2-0.9% (see [0043]). It would have been an obvious matter to the skilled artisan to have adjusted the amounts of Mn and S in Example 13 because Fujimoto teaches the same utility over an overlapping range. Regarding the Ca content, Fujimoto teaches that the inoculant is added as Ca+Ba ([0054]). Fujimoto teaches that Ca and Ba may be used singly, or together in arbitrary ratio (see [0048]). It would have been an obvious matter to have used only Ca because Fujimoto teaches that Ca singly is suitable for the inoculant. Regarding claim 2, Fujimoto does not teach a value of the Desulfurization capacity factor DS is 0.055-0.085%. Fujimoto does not express a value of the DS for the cast iron. However, it is well settled that there is no invention in the discovery of a general formula if it covers a composition described in the prior art, In re Cooper and Foley 1943 C.D. 357, 553 O.G. 177; 57 USPQ 117, Saklatwalla v. Marburg, 620 O.G. 685, 1949 C.D. 77, and In re Pilling, 403 O.G. 513, 44 F(2) 878, 1931 C.D. 75. In the absence of evidence to the contrary, the selection of the proportions of elements would appear to require no more than routine investigation by those of ordinary skill in the art. In re Austin, et al., 149 USPQ 685, 688. In this case the composition of Fujimoto overlaps that which is claimed, and the selection of a composition in the range as claimed would have required no more than a routine investigation of the invention of Fujimoto. For example, if the Example 13 of Fujimoto as described in Table 1 were altered so as to have 0.004% of Ca, then it would have DS value of 0.04/0.76 + 0.019/2.93 + 0.004/1.25 = 0.062%. If there were no calcium in the Example 13, then the value of DS would still be 0.04/0.76 + 0.019/2.93 + 0/1.25 = 0.59%. Thus it is believed that the cast iron as claimed would have been obvious over the compositions taught by Fujimoto. Regarding claims 3 and 12, Fujimoto does not teach a value of the Excess magnesium content RM is 0.015-0.045%. Fujimoto does not express a value of the RM for the cast iron. However, it is well settled that there is no invention in the discovery of a general formula if it covers a composition described in the prior art. In the alternative, if the Example 13 of Fujimoto as described in Table 1 were altered so as to have 0.004% of Ca, then it would have RM value of 0.04 - (0.01 – ( 0.019/2.93 + 0.004/1.25) x 0.76 = 0.039%. Thus it is believed that the cast iron as claimed would have been obvious over the compositions taught by Fujimoto. Claim(s) 1-3 and 12 are rejected under 35 U.S.C. 103 as being unpatentable over US 4450019 A (hereinafter “Satou”), in view of US 20160053351 A1 (hereinafter “Fujimoto”). Regarding claim 1, Satou teaches a ductile cast iron (See title). Satou teaches spherulitic graphite (col 1 or col 2 ll 33-43). Satou teaches that the cast iron has a composition which generally overlaps the claimed cast iron (See claim 1). The composition of the iron of Fujimoto is compared with the claimed iron in the chart below (values in mass %). Element Claim 1 Satou claim 1 C Si Mn P S Mg La + Ce Ca FE/impurities 2.8-3.3 2.5-4.0 0.32-0.40 0.020-0.030 0.020-0.035 0.030-0.050 0.010-0.050 0.0020-0.0050 balance 2.5-3.8 3.5-4.8 1.0 or less 0.1 or less 0.1 or less 0.03-0.1 0.02-0.5 -- balance The difference between the iron of Satou and the claimed iron is that Satou does not envision the addition of calcium. The broad composition of the cast iron of Satou (other than calcium) overlaps the claimed composition, establishing a prima facie case of obviousness. It would have been an obvious matter to the skilled artisan at time of filing to have selected a composition in the range as claimed, because Satou teaches the same utility over an overlapping range. Applicant is directed to MPEP 2144.05. Fujimoto teaches a spheroidal graphite cast iron (see BRIEF SUMMARY OF THE INVENTION or Figs 3-4). Fujimoto teaches that the spheroidal graphite cast iron has a composition which overlaps the claimed composition (See claim 1). Fujimoto teaches that the cast iron can be inoculated with a Ca+Ba ([0054]). Fujimoto teaches that Ca and Ba may be used singly, or together in arbitrary ratio (see [0048]). Fujimoto teaches that the amount of Ca should be 0.0001-0.01% ([0048]). Fujimoto teaches that the inoculant adds strength in the cast iron (see [0048]). It would have been an obvious matter to have used only Ca because Fujimoto teaches that Ca singly is suitable for the inoculant. It would have been an obvious matter to the skilled artisan to have altered the cast iron as by adding the Ca as an inoculant, as taught by Fujimoto, because Fujimoto teaches that this adds strength ([0048]). Regarding claim 2, Satou does not teach a value of the Desulfurization capacity factor DS is 0.055-0.085%. Satou does not express a value of the DS for the cast iron. However, it is well settled that there is no invention in the discovery of a general formula if it covers a composition described in the prior art, In re Cooper and Foley 1943 C.D. 357, 553 O.G. 177; 57 USPQ 117, Saklatwalla v. Marburg, 620 O.G. 685, 1949 C.D. 77, and In re Pilling, 403 O.G. 513, 44 F(2) 878, 1931 C.D. 75. In the absence of evidence to the contrary, the selection of the proportions of elements would appear to require no more than routine investigation by those of ordinary skill in the art. In re Austin, et al., 149 USPQ 685, 688. In this case the composition of Fujimoto overlaps that which is claimed, and the selection of a composition in the range as claimed would have required no more than a routine investigation of the invention of Satou. Regarding claims 3 and 12, Satou does not teach a value of the Excess magnesium content RM is 0.015-0.045%. Satou does not express a value of the RM for the cast iron. However, it is well settled that there is no invention in the discovery of a general formula if it covers a composition described in the prior art. Claims 4 and 13-14 are rejected under 35 U.S.C. 103 as being unpatentable over US 4450019 A (hereinafter “Satou”), in view of US 20160053351 A1 (hereinafter “Fujimoto”), as applied to claim 1 above, and further in view of US 20180148805 A1 (hereinafter “Toshiba”). Regarding claims 4 and 13-14, Satou in view of Fujimoto are applied as stated above. Satou does not teach aluminum present at 0.0020-0.0050% in the cast iron. Satou is silent with regard to aluminum. Toshiba teaches an inoculation for cast iron including Ca and Al (See SUMMARY OF THE INVENTION). Toshiba teaches that the Al improves the graphitization (SUMMARY). Toshiba teaches that the aluminum is added in an amount of 0.001-0.02% of the total cast iron (see SUMMARY OF THE INVENTION), overlapping the amount as claimed. It would have been an obvious matter to the skilled artisan to have altered the cast iron as by adding the Ca as an inoculant, as taught by Fujimoto, because Fujimoto teaches that this adds strength ([0048]), and further to have added Al to the inoculant, because Toshiba teaches that this contributes to graphitization (SUMMARY OF THE INVENTION). Conclusion The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. US 2488511 A teaches to add rare earths to cast iron for spheroidization. US 20170314105 A1 is exemplary of cast iron inoculant technique and composition. Any inquiry concerning this communication or earlier communications from the examiner should be directed to CHRISTOPHER S KESSLER whose telephone number is (571)272-6510. The examiner can normally be reached 9-5:30. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Curt Mayes can be reached at 571-272-1234. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. CHRISTOPHER S. KESSLER Primary Examiner Art Unit 1734 /CHRISTOPHER S KESSLER/ Examiner, Art Unit 1759
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Prosecution Timeline

Sep 22, 2023
Application Filed
Feb 20, 2026
Non-Final Rejection — §103 (current)

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

1-2
Expected OA Rounds
59%
Grant Probability
74%
With Interview (+15.0%)
3y 10m
Median Time to Grant
Low
PTA Risk
Based on 783 resolved cases by this examiner. Grant probability derived from career allow rate.

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