Prosecution Insights
Last updated: April 19, 2026
Application No. 18/264,249

METHOD FOR PRODUCING MOLTEN IRON USING ELECTRIC FURNACE PROVIDED WITH VIDEO DEVICE

Non-Final OA §103§112
Filed
Aug 04, 2023
Examiner
WU, JENNY R
Art Unit
1733
Tech Center
1700 — Chemical & Materials Engineering
Assignee
JFE Steel Corporation
OA Round
1 (Non-Final)
63%
Grant Probability
Moderate
1-2
OA Rounds
3y 1m
To Grant
80%
With Interview

Examiner Intelligence

Grants 63% of resolved cases
63%
Career Allow Rate
529 granted / 838 resolved
-1.9% vs TC avg
Strong +16% interview lift
Without
With
+16.4%
Interview Lift
resolved cases with interview
Typical timeline
3y 1m
Avg Prosecution
45 currently pending
Career history
883
Total Applications
across all art units

Statute-Specific Performance

§101
1.0%
-39.0% vs TC avg
§103
50.5%
+10.5% vs TC avg
§102
12.2%
-27.8% vs TC avg
§112
23.2%
-16.8% vs TC avg
Black line = Tech Center average estimate • Based on career data from 838 resolved cases

Office Action

§103 §112
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 . Status of Claims Claims 1-18 are pending and are presented for this examination. Priority Receipt is acknowledged of certified copies of papers submitted under 35 U.S.C 119(a)-(d), which papers have been placed of record in the file. Information Disclosure Statement The information disclosure statement (IDS) was submitted on 08/04/2023, 09/132024 and 06/17/2025 and is in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statement is being considered by the examiner. 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 5,9 and 10 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 pre-AIA the applicant regards as the invention. Claims 5, 9 and 10 recite the limitation "the remaining cold iron source" in line 5. There is insufficient antecedent basis for this limitation in the claim. It is unclear whether the remaining cold iron source refers to the “the cold iron source remains in the second preheating chamber” or something else. Claim Interpretation In claims 5, 9 and 10, the limitation "the remaining cold iron source is supplied to the melting chamber by the extruder, and the heating of the molten iron is started after confirmation is obtained via the video device that none of the cold iron source remains in the second preheating chamber." is interpreted as conditional limitation because it is recited after conditional term “when”. 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. The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows: 1. Determining the scope and contents of the prior art. 2. Ascertaining the differences between the prior art and the claims at issue. 3. Resolving the level of ordinary skill in the pertinent art. 4. Considering objective evidence present in the application indicating obviousness or nonobviousness. Claim(s) 1-18 are rejected under 35 U.S.C. 103 as being unpatentable over CN’237(CN108642237A) in view of JP’724(JP2004250724). As for claim 1, CN’237 discloses a method producing molten iron using an electric arc furnace (200) provided with a preheating chamber (100) to preheat a cold iron source (501) and a melting chamber (205) to melt the preheated cold iron source (502) to produce molten iron. Figure below illustrates upper sealing sliding plate (101) and lower sealing sliding plate (103) (i.e. claimed cold iron source supporter) that is openable and slidable to move along the horizontal direction such that both sealing sliding plates 101 and 103 can be opened and closed to separate the preheating chamber (100) into a first preheating chamber (102) on a cold iron source introduction side (102) and a second preheating chamber (104) on a melting chamber side, an extruder (119) that is operable to advance and retract along a direction from the second preheating chamber (104) toward the melting chamber (205). The upper sealing sliding plate (101) is opened to dump the cold iron source to the first preheating chamber(102) while lower sealing sliding plate (103) is closed. Then the lower sealing sliding plate is opened to supply the cold iron source from the first preheating chamber to the second preheating chamber for melting. After the cold iron source is melted in the second preheating chamber, it is then supplied to the melting chamber by the extruder (119) for heating by the arc heat in the electric arc furnace. Hence, instant claimed melting process is expected. PNG media_image1.png 669 860 media_image1.png Greyscale A heating process of heating the molten iron in the melting chamber (205) while the cold iron source supported (103) is closed. A new cold iron source is then expected to be introduced into the first preheating chamber. Since the smoke (i.e. claimed exhaust gas) generated from the heating process is used to preheat the new cold iron source (abstract last four lines), instant claimed preheating process is expected. Figure 8 illustrates a tapping process ([0076]) to conduct the heated molten iron out of the electric arc furnace (200) Hence, CN’237 discloses a melting, heating, preheating and tapping process as required by instant claim 1. CN’237 discloses an observing hole provided in the second preheating chamber to observe the cold iron source stacking condition. ([0063]) However, CN’237 does not disclose claimed “video device to observe the second preheating chamber and heating of the molten iron is started based on visual information obtained from the video device of the second preheating chamber after the cold iron source supporter is closed”. JP’724 discloses a method of producing molten iron using an electric arc furnace with a preheating chamber and a melting chamber. JP’724 explicitly discloses (Page 23 last three lines) a camera is installed to photograph the interior of the preheating chamber and the photographed image is used by an image processing device to accurately detect the molten iron level in the preheating chamber (Page 13) for efficiently melting metal before the molten metal is being heated in the melting chamber. Hence, JP’724 discloses instant claimed video device of the second preheating chamber to observe the second preheating chamber. Hence, it would have been obvious to one skill in the art, at the time of the invention is made to install a camera as disclosed by JP’724 to observe the second preheating chamber of CN’237, in the process of CN’237 because JP’724 discloses the camera accurately detects the molten iron level in the preheating chamber for molten iron heating efficiency. As a result of installing a camera of JP’724 in the process of CN’237, instant claimed “heating of the molten metal is started based on visual information via the video device of the second preheating chamber after the cold iron source supporter is closed” would have been obvious in order to timely control the heating of the molten iron for increased molten iron heating efficiency. As for claim 2, CN’237 discloses ([0076]) at the end of the tapping process, new cold iron source is continuously fed from the first preheating chamber to the second preheating chamber and then fed to the electric furnace for melting, which reads on claimed preparation process. The entire process of producing the molten iron is non-intermittent and continuous. Hence, the melting process, the heating process, the preheating process and the tapping process are expected to be in sequence. As for claim 3, the extruder (119) has a bottom plate (116) as illustrated in Figure 1. The bottom plate (116) reads on claimed melting chamber side tip of the extruder positioned at a boundary between the second preheating chamber and the melting chamber. Cold iron source support is expected to be opened during the preparation process to continuously feed the new cold iron source. As for claims 4-5 and 7-10, since JP’724 desires molten iron heating efficiency, it would have been obvious to one skill in the art to start the heating of the molten iron in the melting chamber when all the molten irons in the second preheating chamber are in the subsequent melting chamber for effectively increasing molten iron heating efficiency. When all the molten irons are in the subsequent melting chamber, instant claimed “none of the cold iron source remains in the second preheating chamber after the cold iron source supporter is closed when heating is started” is expected. As for claims 6 and 11-18, due to the purpose of the camera of JP’724 is to accurately detecting the molten metal level in the preheating chamber (Page 13) for efficiently melting iron before the molten metal is being heated in the melting chamber, it would have been obvious to perform the heating process when all the molten iron in the preheating chamber (i.e. claimed predefined amount of cold iron source) are supplied to the melting chamber for increased molten iron heating efficiency. Claim(s) 1-18 are rejected under 35 U.S.C. 103 as being unpatentable over CN’237(CN108642237A) in view of CN’630 (CN211367630U). As for claims 1-3, CN’237 discloses instant claim 1 required limitation as indicated in rejection of claims 1-3 above over CN’237 over JP’724. CN’237 discloses an observing hole provided in the second preheating chamber to observe the cold iron source stacked condition. ([0063]) However, CN’237 does not disclose claimed “video device to observe the second preheating chamber and heating of the molten iron is started based on visual information obtained from the video device of the second preheating chamber after the cold iron source supporter is closed” as required by instant claim 1. CN’630 discloses a similar method of producing molten iron. CN’630 explicitly discloses a camera is provided at the observation hole of a preheating furnace for observing and controlling an actual falling position of the cold iron source to promote high temperature molten iron fast melting the cold iron source. ([0114]) Hence, it would have been obvious to one skill in the art, to provide a camera of CN’630 at the observation hole of CN’237, during the process of CN’237 for the benefit of increased molten iron heating efficiency. As a result of installing a camera of CN’630 in the process of CN’237, instant claimed “heating of the molten metal is started based on visual information via the video device of the second preheating chamber after the cold iron source supporter is closed” would have been obvious in order to timely control the heating of the molten iron for increased molten iron heating efficiency. As for claims 4-5 and 7-10, it would have been obvious to one skill in the art to start the heating of the molten iron in the melting chamber when all the molten irons in the second preheating chamber are in the subsequent melting chamber for increased molten iron heating efficiency purpose. Hence, when all the molten irons are in the subsequent melting chamber, instant claimed “none of the cold iron source remains in the second preheating chamber after the cold iron source supporter is closed when heating is started” is expected. As for claims 6 and 11-18, due to the purpose of CN’630’s camera is for observing and controlling an actual falling position of the cold iron source to promote high temperature molten iron fast melting the cold iron source, it would have been obvious to perform the heating process when all the molten iron in the preheating chamber (i.e. claimed predefined amount of cold iron source) are supplied to the melting chamber for increased molten iron heating efficiency. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to JENNY R WU whose telephone number is (571)270-5515. The examiner can normally be reached on 8:30 AM-5:00 PM. 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, Keith Hendricks can be reached on (571)272-1401. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of an application may be obtained from the Patent Application Information Retrieval (PAIR) system. Status information for published applications may be obtained from either Private PAIR or Public PAIR. Status information for unpublished applications is available through Private PAIR only. For more information about the PAIR system, see http://pair-direct.uspto.gov. Should you have questions on access to the Private PAIR system, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative or access to the automated information system, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /JENNY R WU/Primary Examiner, Art Unit 1733
Read full office action

Prosecution Timeline

Aug 04, 2023
Application Filed
Jan 23, 2026
Non-Final Rejection — §103, §112 (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
63%
Grant Probability
80%
With Interview (+16.4%)
3y 1m
Median Time to Grant
Low
PTA Risk
Based on 838 resolved cases by this examiner. Grant probability derived from career allow rate.

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