Prosecution Insights
Last updated: April 18, 2026
Application No. 18/280,618

ARC EXTINGUISHING UNIT AND AIR CIRCUIT BREAKER COMPRISING SAME

Non-Final OA §103
Filed
Mar 01, 2024
Examiner
BOLTON, WILLIAM A
Art Unit
2831
Tech Center
2800 — Semiconductors & Electrical Systems
Assignee
Ls Electric Co. Ltd.
OA Round
1 (Non-Final)
89%
Grant Probability
Favorable
1-2
OA Rounds
2y 0m
To Grant
95%
With Interview

Examiner Intelligence

Grants 89% — above average
89%
Career Allow Rate
657 granted / 738 resolved
+21.0% vs TC avg
Moderate +6% lift
Without
With
+5.6%
Interview Lift
resolved cases with interview
Fast prosecutor
2y 0m
Avg Prosecution
30 currently pending
Career history
768
Total Applications
across all art units

Statute-Specific Performance

§101
0.1%
-39.9% vs TC avg
§103
51.7%
+11.7% vs TC avg
§102
32.0%
-8.0% vs TC avg
§112
11.1%
-28.9% vs TC avg
Black line = Tech Center average estimate • Based on career data from 738 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 . Claim Objections Claims 1-18 are objected to because: Claims 1-18, “side plates” should be -two side plates- to be more clearly defined. Claims 1-18, “a plurality of grids” should be -a plurality of grid plates- to be more clearly defined. Claim 1, line 7, “the outermost grid” lacks antecedent basis. Claim 2, line 2, “a magnet unit” should be -the magnet unit-. Claim 2, line 3, “the one side plate” and “the other side plate” lack antecedent basis. Claim 4, lines 4-5, “a magnetic field” should be -the magnetic field-. Claim 8, line 2, phrase, “wherein the magnet unit further comprises a third magnet unit coupled to any one of the plurality of grids” is unclear and seems the third magnet can only be logically coupled to either of the outermost grid plates of the stack of grid plates. Claim 9, lines 4-5,“a magnetic field” should be -the magnetic field-. Claim 10, line 8, “a grid’ should be -the grid-. Claim 11, line 2, phrase, “up and down direction” is unclear and depends on the orientation of the mounting of the device. Claim 12, line 4, “the N pole” lack antecedent basis. Claim 12, line 5, “the S pole” lack antecedent basis. Claim 13, line 3, “the N pole” lack antecedent basis. Claim 13, line 4, “the S pole” lack antecedent basis. Claim 15, line 2, phrases, “downward” and “a lower end” are unclear and depends on the orientation of the mounting of the device. Claim 16, line 3, phrase, “protruding downward” is unclear and depends on the orientation of the mounting of the device. Claim 17, line 11, “an arc” should be -the arc-. Claim 17, lines 11-12, “a fixed contact” and “a movable contact” should be -the fixed contact- and “the movable contact-. Claim 17, line 13, “the outermost grid” lacks antecedent basis. Claim 18, line 2, phrase, “a low runner protruding upward from the fixed contact” is unclear and leave doubts as to what feature is being referred to, since “a low runner” is in reference to what and “upward” depends on the orientation of the mounting of the device. Claim 18, line 3, phrase, “a protruding contact protruding upward from the movable contact” is unclear and depends on the orientation of the mounting of the device. Appropriate correction is required. 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. Claims 1-7 and 12 are rejected under 35 U.S.C. 103 as being unpatentable over Lee, KR20180048151 in view of Ye et al, CN 207319963 [Ye]. Regarding claim 1, Lee discloses (figs.1-10) an arc extinguishing unit (3 ), comprising: side plates (21, 22) spaced apart from each other and disposed to face each other; a plurality of grids (30) disposed between the side plates (21, 22), spaced apart from each other, and coupled to the side plates (21, 22), respectively; and a magnet unit (50, 55) forming a magnetic field for changing a path of an arc formed between a fixed contact (7) and a movable contact (8) disposed to be spaced apart from the fixed contact (7). Lee fails to explicitly disclose the magnet unit disposed adjacent to the outermost grid adjacent to the fixed contact among the plurality of grids. Ye 9963’ discloses (figs.3-5) an arc extinguishing chamber (10) comprising a magnet unit (21) disposed adjacent to an outermost grid (12) adjacent to a fixed contact (6) among a plurality of grids (11). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the magnetic unit of Lee with the placement of the magnet unit of Ye,9963, thereby providing a utility model has faster switching speed and longer electrical life, performance is more stable and reliable. Regarding claim 2, Lee further discloses where the magnet unit (50, 55) comprises a magnet unit disposed to be symmetrical with respect to a central portion of the grid (30) disposed between the one side plate (21) and the other side plate (22). Regarding claim 3, Lee further discloses where the magnet unit (50, 55) is disposed on at least one of the grid (30) and the side plate (21). Regarding claim 4, Lee further discloses where the magnet unit (50, 55) comprises: a case (40) formed to define a storage part (43) therein and coupled to the side plate (21), and a magnetic body (50) accommodated in the storage part (43) and configured to form a magnetic field. Regarding claim 5, Lee further discloses where the magnet unit (50, 55) further comprises an insulator (40, formed of an insulating material) accommodated in the storage part (43) and formed to surround the magnetic body (50). Regarding claim 6, Lee further discloses where the case (40) guides an arc (via, 42) such that an arc generated flows toward the grid (30). Regarding claim 7, Lee further discloses where the magnet unit (50, 55) comprises: a first magnet unit (50) coupled to the side plate (21) and extending in a direction in which the plurality of grids (30) coupled to the side plate (21) are aligned; and a second magnet unit (55) coupled to the side plate (22) facing the side plate (21) to which the first magnet unit (50) is coupled and disposed at a position corresponding to the first magnet unit (50). Regarding claim 12, Lee further discloses where the magnetic body (50, 55) of the first magnet unit (50) and the second magnet unit (55) comprises: a first surface magnetized to the N pole; and a second surface magnetized to the S pole, and where the first surface is disposed along a direction in which the first magnet unit (50) and the second magnet unit (55) are away from each other [see fig.8]. Regarding claim 17, Lee discloses (figs.1-10) an air circuit breaker (1), comprising: a fixed contact (7); a movable contact (8) moved in a direction toward or away from the fixed contact (7); and an arc extinguishing unit (3) positioned adjacent to the fixed contact (7) and the movable contact (8), and configured to extinguish an arc generated when the fixed contact (7) and the movable contact (8) are spaced apart, where the arc extinguishing unit (3) comprises: side plates (21, 22) spaced apart from each other and disposed to face each other; a plurality of grids (30) disposed between the side plates (21, 22), spaced apart from each other, and coupled to the side plates (21, 22), respectively; and a magnet unit (50, 55) forming a magnetic field for changing a path of an arc formed between a fixed contact (7) and a movable contact (8) disposed to be spaced apart from the fixed contact (7). Lee fails to explicitly disclose the magnet unit disposed adjacent to the outermost grid adjacent to the fixed contact among the plurality of grids. Ye, 9963’ discloses (figs.3-5) an arc extinguishing chamber (10) comprising a magnet unit (21) disposed adjacent to an outermost grid (12) adjacent to a fixed contact (6) among a plurality of grids (11). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the magnetic unit of Lee with the placement of the magnet unit of Ye,9963’ thereby providing a utility model has faster switching speed and longer electrical life, performance is more stable and reliable. Claim 8 is rejected under 35 U.S.C. 103 as being unpatentable over Lee and Ye 9963’ and further in view of Juds et al, US 9343251 [Juds]. Regarding claim 8, Lee and Ye, 9963’ fail to disclose wherein the magnet unit further comprises a third magnet unit coupled to any one of the plurality of grids. Juds discloses (figs.1-11) an electrical switching apparatus (2) where a magnet unit further comprises a third magnet unit (64) coupled to any one of a plurality of grids (28). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to further modify the magnetic unit of Lee with the magnet unit taught by Juds, thereby providing an improve magnitude and orientation of the magnetic field which drives the arc into the arc splitter plates, regardless of the initial arc motion direction. Claim 18 is rejected under 35 U.S.C. 103 as being unpatentable over Lee and Ye 9963’ and further in view of Ye et al, CN 109166774 [Ye]. Regarding claim 18, Lee further comprising: a low runner (36) protruding upward from the fixed contact (7); but silent on a protruding contact protruding upward from the movable contact and contacting the low runner when the movable contact contacts the fixed contact. Ye, 6774’ discloses (figs.2-4) a protruding contact (18) protruding upward from a movable contact (17) and contacting a low runner (2) when the movable contact (17) contacts a fixed contact (4). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to further modify the circuit breaker of Lee with the inclusion of the movable assembly of Ye, 6774’, thereby providing a protruding contact protruding upward from the movable contact, thus preventing arcing at the main contacts, extending service life of the main contacts. Allowable Subject Matter Claims 9-11 and 13-16 are objected to as being dependent upon a rejected base claim but would be allowable if rewritten to overcome claim objections and in independent form including all of the limitations of the base claim and any intervening claims. The following is a statement of reasons for the indication of allowable subject matter: Regarding claim 9, the prior art fails to teach or show, alone or in combination, the claimed arc extinguishing unit, where the third magnet unit comprises, a case formed to define a storage part therein and coupled to the grid or the side plate; a magnetic body accommodated in the storage part and configured to form a magnetic field; and a coupling member for coupling the case to a coupling groove formed in the grid. The prior art, either alone or in combination cannot reasonably be construed as adequately teaching the above limitations in combination with the remaining claim elements. Conclusion The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Shea, Lim et al, Ruempler et al, Engewald, Seo, Theisen et al and Hamada et al are examples of circuit breaker comprising arc extinguishing units configured similar to the present invention. Any inquiry concerning this communication or earlier communications from the examiner should be directed to WILLIAM A BOLTON whose telephone number is (571)270-5887. The examiner can normally be reached Mon-Fri: 7:30AM - 5:00PM. 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, Renee S. Luebke can be reached at 571-272-2009. 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. /WILLIAM A BOLTON/Primary Examiner, Art Unit 2831
Read full office action

Prosecution Timeline

Mar 01, 2024
Application Filed
Apr 01, 2026
Non-Final Rejection — §103 (current)

Precedent Cases

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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
89%
Grant Probability
95%
With Interview (+5.6%)
2y 0m
Median Time to Grant
Low
PTA Risk
Based on 738 resolved cases by this examiner. Grant probability derived from career allow rate.

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