Prosecution Insights
Last updated: April 19, 2026
Application No. 18/288,330

ARC EXTINGUISHING UNIT AND AIR CIRCUIT BREAKER COMPRISING SAME

Final Rejection §103
Filed
Oct 25, 2023
Examiner
BOLTON, WILLIAM A
Art Unit
2831
Tech Center
2800 — Semiconductors & Electrical Systems
Assignee
Ls Electric Co. Ltd.
OA Round
2 (Final)
89%
Grant Probability
Favorable
3-4
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 . Response to Amendment The Amendment filed January 7th, 2026 has been entered. Claims 1 and 3-14 are pending. Claims 1 and 3-13 have been amended, claim 2 has been canceled and claim 14 has been added by the Applicant. Applicant’s amendments have overcome claim objections. 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, 3-5, 7 and 12-13 are rejected under 35 U.S.C. 103 as being unpatentable over Maier et al, US 4612426 [Maier] in view of Gao et al, CN 203839321 [Gao]. Regarding claim 1, Maier discloses (figs.1-9) an arc extinguishing unit (22), comprising: a plurality of side plate parts (48) spaced apart from each other and disposed to face each other; a plurality of grids (44) located between the plurality of side plate parts (48), spaced apart from each other, and coupled to the plurality of side plate parts (48), respectively; and a cover assembly (50) disposed above the plurality of grids (44) and configured to cover the plurality of grids, (44), where each side plate part (48) of the plurality of side plate parts (48) comprises: a gassing material (52) that generates molecules that extinguish an arc when heat generated by the arc is applied [col.6, lines 54-58], an outer support plate (48), disposed outside the gassing material (52), coupled to the plurality of grids (44), and pressurizing and fixing the gassing material (52) toward the plurality of grids (44), where each grid (44) of the plurality of grids (44) comprises a plurality of protrusion parts (49) protruding from both side surfaces (57) and coupled to the plurality of side plate parts (48). Maier fails to explicitly disclose wherein each protrusion part of the plurality of protrusion parts penetrates the gassing material and the outer support plate of each side plate part of the plurality of side plate parts and is coupled to the gassing material and the outer support plate of each side plate part of the plurality of side plate parts. Gao discloses (figs.1-4) an arc extinguishing unit where each protrusion part of a plurality of protrusion parts penetrates a gassing material (7) and an outer support plate (2) of each side plate part of a plurality of side plate parts (2) and is coupled to the gassing material (7) and the outer support plate (2) of each side plate part of the plurality of side plate parts (2). 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 gassing material Maier with the teaching of the gassing material of Gao, thereby providing a secured interlocking arrangement between the gassing material and the outer support wall, thus providing a rugged unitary arc chute assembly. Regarding claim 3, Maier further discloses where the outer support plate (48) comprises a fiber-reinforced polyester composite [col.4, lines 34-37]. Regarding claim 4, Maier further discloses where each protrusion part (49) of the plurality of protrusion parts (49) comprises a body part (labeled in fig.7, below) extending from a side surface (57) of a respective grid (44); and a first protrusion (labeled in fig.7, below) and a second protrusion (labeled in fig.7, below) extending from the body part (labeled in fig.7, below) to both sides. PNG media_image1.png 312 410 media_image1.png Greyscale Regarding claim 5, Maier further discloses where the first protrusion (labeled in fig.7, above) and the second protrusion (labeled in fig.7, above) are spaced apart from each other and extend outwardly from the body part (labeled in fig.7, above), and extend in a direction away from each other so as to be symmetrical about a central portion (labeled in fig.7, above) of the body part (labeled in fig.7, above). Regarding claim 7, Maier further discloses where a through hole (51) into which a protrusion part (49) of the plurality of protrusion parts (49) is inserted is formed in the outer support plate (48), and where the outer support plate (48) comprises, a central member formed in the through hole (51) and extending across the through hole (51) so that the first protrusion (labeled in fig.7, above) and the second protrusion (labeled in fig.7, above) are inserted separately from each other. Regarding claim 12, Maier discloses (figs.1-9) an air circuit breaker (10), comprising: a fixed contact (18); a movable contact (20) configured to be movable in a direction toward or away from the fixed contact (18); and an arc extinguishing unit (22) disposed adjacent to the fixed contact (18) and the movable contact (20), and configured to extinguish an arc generated when the fixed contact (18) and the movable contact (20) are spaced apart, where the arc extinguishing unit (22) comprises: a plurality of side plate parts (48) spaced apart from each other and disposed to face each other; a plurality of grids (44) located between the plurality of side plate parts (48), spaced apart from each other, and coupled to the plurality of side plate parts (48), respectively; and a cover assembly (50) disposed above the plurality of grids (44) and configured to cover the plurality of grids (44), and where each side plate part (48) of the plurality of side plate parts (48) comprises: a gassing material (52) that generates molecules that extinguish the arc when heat generated by the arc is applied [col.6, lines 54-58]; and an outer support plate (48), disposed outside the gassing material (52), coupled to the plurality of grids (44), and pressurizing and fixing the gassing material (52) toward the plurality of grids (44), where each grid (44) of the plurality of grids (44) comprises a plurality of protrusion parts (49) protruding from both side surfaces (57) and coupled to the plurality of side plate parts (48), and an outer support plate (48), disposed outside the gassing material (52), coupled to the plurality of grids (44), and pressurizing and fixing the gassing material (52) toward the plurality of grids (44), where each grid (44) of the plurality of grids (44) comprises a plurality of protrusion parts (49) protruding from both side surfaces (57) and coupled to the plurality of side plate parts (48). Maier fails to explicitly disclose wherein each protrusion part of the plurality of protrusion parts penetrates the gassing material and the outer support plate of each side plate part of the plurality of side plate parts and is coupled to the gassing material and the outer support plate of each side plate part of the plurality of side plate parts. Gao discloses (figs.1-4) an arc extinguishing unit where each protrusion part of a plurality of protrusion parts penetrates a gassing material (7) and an outer support plate (2) of each side plate part of a plurality of side plate parts (2) and is coupled to the gassing material (7) and the outer support plate (2) of each side plate part of the plurality of side plate parts (2). 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 gassing material Maier with the teaching of the gassing material of Gao, thereby providing a secured interlocking arrangement between the gassing material and the outer support wall, thus providing a rugged unitary arc chute assembly. Regarding claim 13, Maier further comprising an arc runner (46) disposed on a fixed contact terminal (16) to which the fixed contact (18) is connected and extending from the fixed contact terminal (16) toward the plurality of grids (44). Claim 8 is rejected under 35 U.S.C. 103 as being unpatentable over Maier and Gao further in view of Pollitt et al, US 7488915 [Pollitt]. Regarding claim 8, Maier and Gao disclose the claimed invention, but fails to explicitly disclose wherein the cover assembly comprises: an upper frame disposed at a top and through which a lattice exhaust outlet is formed in a central portion; a mesh part disposed below the upper frame and composed of a plurality of layers, each layer having different wire diameters; a first insulation filter disposed below the mesh part and having a first exhaust hole formed in a partial area thereof; a second insulation filter disposed below the first insulation filter and having a second exhaust hole formed in an area different from the first exhaust hole of the first insulation filter; and a spacer interposed between the first insulation filter and the second insulation filter to maintain a distance between the first insulation filter and the second insulation filter. Pollitt discloses (figs.1-9) a circuit breaker (2) an arc chute assembly (50) cover assembly (200) comprises: an upper frame (288) disposed at a top and through which a lattice exhaust outlet (292’) is formed in a central portion; a mesh part (250) disposed below the upper frame (288) and composed of a plurality of layers (252, 254, 256), each layer having different wire diameters [col.10, lines 3-6]; a first insulation filter (206) disposed below the mesh part (250) and having a first exhaust hole (208) formed in a partial area (206) thereof; a second insulation filter (202) disposed below the first insulation filter (206) and having a second exhaust hole (204) formed in an area (214) different from the first exhaust hole (208) of the first insulation filter (206); and a spacer (220, 218) interposed between the first insulation filter (206) and the second insulation filter (202) to maintain a distance between the first insulation filter (206) and the second insulation filter (202). 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 cover assembly of Maier with the inclusion of the cover assembly of Pollitt, thereby providing a filter assembly that is desirable to release ionized gases in a safe manner which aids in the controlling of the flow rate, cooling and de-ionizing of the arc gases, which can be harmful to other electrical components. Claim 9 is rejected under 35 U.S.C. 103 as being unpatentable over Maier, Gao and Pollitt and further in view of Youngkok, KR 20180124825. Regarding claim 9, Maier, Gao and Pollitt disclose the claimed invention, including the cover assembly (200), the mesh part (250), the first insulation filter (206), the spacer (220, 218), and the second insulation filter (202); but fail to explicitly disclose a cover body; and a packing part coupled to the cover body, blocking a space between an outside and the cover assembly, and maintaining internal pressure, and wherein the cover assembly has coupling protrusions protruding from sidewalls of an inner space and formed to be fitted to sidewalls of the first insulation filter, the spacer, and the second insulation filter. Youngkook discloses a similar arc extinguishing device (1c) comprising a cover body (40); and a packing part (90) coupled to the cover body (40), blocking a space between an outside and a cover assembly (50, 90, 40), and maintaining internal pressure, and where the cover assembly (50, 90, 40) has coupling protrusions (43) protruding from sidewalls (44) of an inner space (41) and formed to be fitted to sidewalls of the first insulation filter (85), a spacer (99), and a second insulation filter (80). 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 cover assembly of Maier with the inclusion of the cover assembly of Youngkook, thereby configured to increase the internal pressure of the arc extinguishing device, further increasing the arc voltage when the current is interrupted, thus improving the arc extension performance. Response to Arguments Applicant’s amendments and arguments filed January 7th, 2026 have been fully considered. All relevant arguments have been fully addressed in the new rejections, above. Allowable Subject Matter Claims 6 and 10-11 are objected to as being dependent upon a rejected base claim but would be allowable if rewritten 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 6, the prior art fails to teach or show, alone or in combination, the claimed arc extinguishing unit, where a U-groove capable of absorbing left and right deformation of the first protrusion and the second protrusion by a first external force is formed in a space between the first protrusion and the second protrusion, and where a concave groove capable of absorbing back and forth deformation of the first protrusion and the second protrusion by a second external force is formed between the first protrusion and the second protrusion and the body part. Regarding claim 10, the prior art fails to teach or show, alone or in combination, the claimed arc extinguishing unit, where the first insulation filter is composed of a first region in which exhaust holes of the plurality of exhaust holes are formed in an entire area along the width direction; a second region in which exhaust holes of the plurality of exhaust holes are formed in a partial area in the width direction; and a third region in which exhaust holes of the plurality of exhaust holes are not formed. Claim 14 is allowed. The following is an examiner’s statement of reasons for allowance: Regarding claim 14, the prior art fails to teach or show, alone or in combination, the claimed arc extinguishing unit, where a U-groove capable of absorbing left and right deformation of the first protrusion and the second protrusion by a first external force is formed in a space between the first protrusion and the second protrusion, and where a concave groove capable of absorbing back and forth deformation of the first protrusion and the second protrusion by a second external force is formed between the first protrusion and the second protrusion and the body part. 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. Any comments considered necessary by applicant must be submitted no later than the payment of the issue fee and, to avoid processing delays, should preferably accompany the issue fee. Such submissions should be clearly labeled “Comments on Statement of Reasons for Allowance.” Conclusion Applicant's amendment necessitated the new grounds of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a). A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action. 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 2833
Read full office action

Prosecution Timeline

Oct 25, 2023
Application Filed
Oct 03, 2025
Non-Final Rejection — §103
Jan 07, 2026
Response Filed
Feb 23, 2026
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

3-4
Expected OA Rounds
89%
Grant Probability
95%
With Interview (+5.6%)
2y 0m
Median Time to Grant
Moderate
PTA Risk
Based on 738 resolved cases by this examiner. Grant probability derived from career allow rate.

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