Prosecution Insights
Last updated: April 19, 2026
Application No. 17/917,440

ELECTRIC ARC FURNACE

Non-Final OA §101§103§112
Filed
Oct 06, 2022
Examiner
OLIVA, STEPHANIE RENEE
Art Unit
3761
Tech Center
3700 — Mechanical Engineering & Manufacturing
Assignee
Digimet 2013 Sl
OA Round
1 (Non-Final)
20%
Grant Probability
At Risk
1-2
OA Rounds
3y 8m
To Grant
0%
With Interview

Examiner Intelligence

Grants only 20% of cases
20%
Career Allow Rate
1 granted / 5 resolved
-50.0% vs TC avg
Minimal -20% lift
Without
With
+-20.0%
Interview Lift
resolved cases with interview
Typical timeline
3y 8m
Avg Prosecution
42 currently pending
Career history
47
Total Applications
across all art units

Statute-Specific Performance

§101
1.2%
-38.8% vs TC avg
§103
47.0%
+7.0% vs TC avg
§102
24.3%
-15.7% vs TC avg
§112
22.3%
-17.7% vs TC avg
Black line = Tech Center average estimate • Based on career data from 5 resolved cases

Office Action

§101 §103 §112
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 . Claim Rejections - 35 USC § 101 35 U.S.C. 101 reads as follows: Whoever invents or discovers any new and useful process, machine, manufacture, or composition of matter, or any new and useful improvement thereof, may obtain a patent therefor, subject to the conditions and requirements of this title. Regarding Claim 14: the claimed invention is directed to non-statutory subject matter. The claim does not fall within at least one of the four categories of patent eligible subject matter because it presents a “use” claim. It has been held that "Use" claims that do not purport to claim a process, machine, manufacture, or composition of matter fail to comply with 35 U.S.C. 101. In re Moreton, 288 F.2d 708, 709, 129 USPQ 227, 228 (CCPA 1961) Claim Rejections - 35 USC § 112 The following is a quotation of 35 U.S.C. 112(b): (b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention. The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph: The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention. Claims 6-9 and 11 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention. These claims present the limitation of “alumina-based.” However, the way in which alumina-based limits the claims is not clear in terms of amount or substance. For the sake of prosecution, “alumina-based” will be interpreted as “containing alumina” Claims 13 is rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention. These claims present the limitation of “silica-based.” However, the way in which silica-based limits the claims is not clear in terms of amount or substance. For the sake of prosecution, “silica -based” will be interpreted as “containing silica” Claims 13 and 7 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention. The claims present the limitation “self-sintering” the intended meaning of which is unclear and does not appear to be further elaborated by the applicant’s specification. In line with the above interpretations, the relative claims will be interpreted as containing “alumina” and “silica” respectively. Claim Rejections - 35 USC § 103 In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status. 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. Claims 1-5, and 12-14 are rejected under 35 U.S.C. 103 as being unpatentable over Carabin (US 2020/0239980 A1) in view of Okubo (JP2010052973A): PNG media_image1.png 910 738 media_image1.png Greyscale PNG media_image2.png 760 764 media_image2.png Greyscale PNG media_image3.png 980 1070 media_image3.png Greyscale Regarding Claim 1: Carabin teaches a direct current plasma arc furnace (plasma arc furnace Abstract) for melting (“melting” [0002]) a material (“materials” [0003]) by production of electric arcs (“DC Arcs” [0002]) and providing a molten product (“molten slag” [0003]) , the furnace (Figure 2 F “furnace” [0024] ) comprising: a tank (Figure 2 “Tank”) comprising: a crucible (Figure 2 and 4 Crucible) delimiting a chamber (Figure 4 “Chamber”) configured to receive material to be melted and/or treated (Figure 4 Element 5) ; a plurality of refractory walls surrounding the outer surface of the crucible (Figure 4 shows a plurality of refractory walls surrounding the outer surface of the crucible); and a metallic frame (“steel shell” [0035]) covering the refractory walls (Figure 3 further shows that the steel shell covers the refractory walls); and -a heating system (“heating” system Abstract) configured for heating (“heating” system Abstract) the received material (“materials” [0003]), the heating system comprising a first electrode (Figure 2 “First Electrode”) acting as cathode (The prior art further teaches that the first electrode acts as a “cathode” [0044]) and a second electrode (Figure 2 “Second Electrode”) acting as anode (The prior art further teaches that the second electrode acts as a “anode” [0044]), wherein the first electrode is a movable electrode (The prior art further teaches that the first electrodes “slowly move” [0030] during operation of the furnace) configured to project vertically into the chamber delimited by the crucible (Figure 2 further shows that the electrode projects vertically into the chamber) ; the crucible being part of an anode system also comprising said second electrode (Figure 2 further shows that the crucible is a part of the anode system comprising the second electrode) and at least one part connecting the crucible and the second electrode (Figure 2 further shows at least one part connecting the crucible to the second electrode), said crucible having a double function: receiving and holding material to be melted and providing electric conduction for the flow of current to heat said material (The prior art further teaches that the crucible receives and holds material to be melted and acts for “transferring current through the slag melt” Abstract which reads on the limitation of the claim), in such a way that, the voltage potential difference between the cathode and any point of the surface of the crucible defined to be in contact with the material to be melted and/or treated is the same (The prior art teaches that the cathode remains in contact with the material to be melted inside of the crucible [0030] which would be understood to one of ordinary skill in the art maintain the same voltage potential difference between the elements). Carabin does not explicitly teach that the crucible is made of a material comprising at least 98% of synthetic graphite However, Okubo does teach a plasma arc furnace (Abstract) wherein the crucible is made of graphite (“crucible made of graphite” [0025]). The prior art teaches that the crucible is wholly made of graphite which would be understood by one of ordinary skill in the art that it is at a percentage of at least 98%. Additionally, the art does not specify whether the graphite in question is synthetic or not. However, as naturally obtained graphite and synthetic graphite are known equivalents in the art, it would be obvious to one of ordinary skill to substitute one for the other. Therefore, it would be obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify the invention of Carabin such that the crucible is made of graphite as taught by Okubo or synthetic graphite as it has been held that substituting equivalents known for the same purpose requires only routine skill in the art MPEP 2144.06 In re Ruff, 256 F.2d 590, 118 USPQ 340 Regarding Claim 2: Carabin as modified by Okubo further teaches the heating system comprises a plasma torch (“plasma torch” [0021]). Regarding Claim 3: Carabin as modified by Okubo further teaches that the cathode (Figure 2 “Cathode”) is made graphite (“made of graphite” [0028]). Carabin does not explicitly teach that the cathode is made of a material comprising at least 98% of synthetic graphite. However, the prior art teaches that the cathode is wholly made of graphite which would be understood by one of ordinary skill in the art that it is at a percentage of at least 98%. Additionally, the art does not specify whether the graphite in question is synthetic or not. Therefore, it would be obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify the invention of Carabin such that the cathode is made of synthetic graphite as it has been held that substituting equivalents known for the same purpose requires only routine skill in the art MPEP 2144.06 In re Ruff, 256 F.2d 590, 118 USPQ 340 Regarding Claim 4: Carabin as modified by Okubo further teaches said at least one part of the anode system comprises: a first elongated portion (Figure 2 shows that the one part has a first elongated portion) having a first end connected to the bottom wall of the crucible and extending radially therefrom (Figure 2 further shows that the first elongated portion has a first end connected to the bottom wall of the crucible and that the iterations of the anode system are distributed and extend radially); and a second elongated portion (Figure 2 “Second elongated portion”) having a first end connected to the second end of the first elongated portion (Figure 2 further shows that the first end of the second elongated portion is connected to the second end of the first elongated portion) , the second elongated portion extending vertically until its second end shows up outside the furnace (Figure 2 further shows that the second elongate portion extends vertically such that its second end extends beyond the furnace). Regarding Claim 5: Carabin as modified by Okubo further teaches the plurality of refractory walls (Figure 4 shows a plurality of refractory walls surrounding the outer surface of the crucible) disposed between the outer surface of the crucible (Figure 4 Crucible) and the metallic frame (“steel shell” [0035]) comprises: a first layer of refractory material vertically surrounding the perimeter wall of the crucible (Figure 4 “1st Refractory Layer”); a second layer of refractory material vertically surrounding the first layer (Figure 4 “2nd Refractory Layer”); a third layer of refractory material disposed beneath the bottom portion of the crucible (Figure 4 “3rd Refractory Layer”); and a fourth layer (14D) of refractory material vertically surrounding the second layer (Figure 4 “2nd Refractory Layer”) and in contact with the outer metallic frame (Figure 4 further shows that the fourth layer is in contact with the outer metallic shell). Regarding Claim 12: Carabin as modified by Okubo further teaches that the fourth layer (Figure 4 “4th refractory layer”) extends downwards with respect to the third layer ((Figure 4 “3rd refractory layer”), surrounding previous refractory portions disposed around the crucible (Figure 4 further shows that the fourth layer surrounds previous refractory layers) Regarding Claim 13: Carabin as modified by Okubo further teaches that the furnace further comprises a fifth layer (Figure 4 “5th Refractory Layer) and that the of refractory material surrounding the second elongated portion of the anode system (Figure 4 further shows that the material surrounds the elongated portion of the anode system), the fifth layer being a silica-based refractory (the prior art further teaches that the refractory layers may be made of “silica” Claim 8). Regarding Claim 14: Carabin as modified by Okubo further teaches use of the furnace (“furnace” Abstract) for melting (“melting” [0002]) metals and/or metallic wastes and/or by-products containing metals and other chemical compounds (“materials” [0003] such as metals, metallic wastes, or biproducts [0002-0003]). Claims 6-7 are rejected under 35 U.S.C. 103 as being unpatentable over Carabin (US 2020/0239980 A1) and Okubo (JP2010052973A) in further view of Chen (US 2020/0361827 A1): Regarding Claim 6: Carabin as modified by Okubo does not teach that the first layer comprises alumina-based corundum. However, Chen does teach a thermally insulating layer comprising alumina-based corundum (“corundum” [0076]). Therefore, it would be obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify the invention of Carabin as modified by Okubo such that the first layer is made of alumina-based corundum as it has been held that substituting equivalents known for the same purpose requires only routine skill in the art MPEP 2144.06 In re Ruff, 256 F.2d 590, 118 USPQ 340 . In both cases, the layer serves the purpose of providing a “thermal insulating layer” [0163]. Regarding Claim 7: Carabin as modified by Okubo and Chen further teaches that the layer is made of alumina-based corundum having an amount of alumina larger than >85% (“mass percent content of Alumina in the corundum is above 99% [Chen Claim 11]) Claims 8-9 are rejected under 35 U.S.C. 103 as being unpatentable over Carabin (US 2020/0239980 A1) and Okubo (JP2010052973A) in further view of Debastiani (US 2020/0087214 A1): Regarding Claim 8: Carabin as modified by Okubo does teach that the refractory layers may comprise “alumina” layers (Claim 8) Carabin as modified by Okubo does not explicitly teach that the second layer comprises alumina-based concrete. However, Debastiani a layer does teach a layer, for use in high heat metallurgical processes that comprises alumina-based concrete (cured “calcium aluminate cement” [0073] which becomes concrete upon curing) Therefore, it would be obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify the invention of Carabin as modified by Okubo such that the second layer is made of alumina-based concrete as it has been held that substituting equivalents known for the same purpose requires only routine skill in the art MPEP 2144.06 In re Ruff, 256 F.2d 590, 118 USPQ 340. In both cases, the layer serves the purpose of providing a insulating “lining layer” [0073]. Regarding Claim 9: Carabin as modified by Okubo does teach that the refractory layers may comprise “alumina” layers (Carabin Claim 8) Carabin as modified by Okubo does not explicitly teach that the second layer comprises alumina-based concrete having an amount of alumina larger than 90%. However, Debastiani a layer does teach a layer, for use in high heat metallurgical processes that comprises alumina-based concrete (cured “calcium aluminate cement” [0073] which becomes concrete upon curing) wherein the amount of alumina larger than 90% (“95% Al2O3” [0088]). Therefore, it would be obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify the invention of Carabin as modified by Okubo such that the second layer is made of alumina-based concrete as it has been held that substituting equivalents known for the same purpose requires only routine skill in the art MPEP 2144.06 In re Ruff, 256 F.2d 590, 118 USPQ 340. In both cases, the layer serves the purpose of providing a insulating “lining layer” [0073]. Claims 10-11 are rejected under 35 U.S.C. 103 as being unpatentable over Carabin (US 2020/0239980 A1), Okubo (JP2010052973A) and Debastiani (US 2020/0087214 A1) in further view of McCollum (US Patent No 4,900,249): Regarding Claim 10: Carabin as modified by Okubo does not teach that the refractory layers comprise calcined bauxite. However, McCollum does teach a lined refractory material for a furnace wherein the layer comprises calcined bauxite (Col 3 Line 6) Therefore, it would be obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify the invention of Carabin as modified by Okubo such that the third and fourth layers comprise calcined bauxite as it has been held that substituting equivalents known for the same purpose requires only routine skill in the art MPEP 2144.06 In re Ruff, 256 F.2d 590, 118 USPQ 340. In both cases, the layer serves the purpose of providing an insulating layer and contain the “molten” material being processed (Abstract). Regarding Claim 11: Carabin as modified by Okubo does not teach that the third layer and the fourth layer also comprise alumina-based concrete. However, Debastiani a layer does teach a layer, for use in high heat metallurgical processes that comprises alumina-based concrete (cured “calcium aluminate cement” [0073] which becomes concrete upon curing) Therefore, it would be obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify the invention of Carabin as modified by Okubo such that the third and fourth layers comprise alumina-based concrete as suggested by Debastiani as it has been held that substituting equivalents known for the same purpose requires only routine skill in the art MPEP 2144.06 In re Ruff, 256 F.2d 590, 118 USPQ 340. In both cases, the layer serves the purpose of providing an insulating “lining layer” [0073]. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to SOLAN OLIVA whose telephone number is (571-)272-2518. The examiner can normally be reached Monday-Thursday 7:00-3:00. 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, Ibrahime Abraham can be reached at (571) 270-8241. The fax phone number for the organization where this application or proceeding is assigned is 571-270-5569. 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. /SOLAN OLIVA/Examiner, Art Unit 3761 /IBRAHIME A ABRAHAM/Supervisory Patent Examiner, Art Unit 3761
Read full office action

Prosecution Timeline

Oct 06, 2022
Application Filed
Nov 06, 2025
Non-Final Rejection — §101, §103, §112 (current)

Precedent Cases

Applications granted by this same examiner with similar technology

Patent 12543889
TRANSVERSELY-LOADABLE ROTISSERIE BASKETS FOR GRILLS
2y 5m to grant Granted Feb 10, 2026
Patent 12502020
Apparatus for Infusing a Liquid
2y 5m to grant Granted Dec 23, 2025
Study what changed to get past this examiner. Based on 2 most recent grants.

AI Strategy Recommendation

Get an AI-powered prosecution strategy using examiner precedents, rejection analysis, and claim mapping.
Powered by AI — typically takes 5-10 seconds

Prosecution Projections

1-2
Expected OA Rounds
20%
Grant Probability
0%
With Interview (-20.0%)
3y 8m
Median Time to Grant
Low
PTA Risk
Based on 5 resolved cases by this examiner. Grant probability derived from career allow rate.

Sign in with your work email

Enter your email to receive a magic link. No password needed.

Personal email addresses (Gmail, Yahoo, etc.) are not accepted.

Free tier: 3 strategy analyses per month