Prosecution Insights
Last updated: April 19, 2026
Application No. 18/717,068

MULTI-LEVEL INVERTER USING WIDE-BAND-GAP SEMICONDUCTOR DEVICES IN A POWER TOOL

Non-Final OA §102§103
Filed
Jun 06, 2024
Examiner
DHAKAL, BICKEY
Art Unit
2896
Tech Center
2800 — Semiconductors & Electrical Systems
Assignee
Milwaukee Electric Tool Corporation
OA Round
1 (Non-Final)
84%
Grant Probability
Favorable
1-2
OA Rounds
2y 5m
To Grant
99%
With Interview

Examiner Intelligence

Grants 84% — above average
84%
Career Allow Rate
616 granted / 732 resolved
+16.2% vs TC avg
Strong +16% interview lift
Without
With
+16.5%
Interview Lift
resolved cases with interview
Typical timeline
2y 5m
Avg Prosecution
43 currently pending
Career history
775
Total Applications
across all art units

Statute-Specific Performance

§101
2.4%
-37.6% vs TC avg
§103
41.8%
+1.8% vs TC avg
§102
28.0%
-12.0% vs TC avg
§112
24.5%
-15.5% vs TC avg
Black line = Tech Center average estimate • Based on career data from 732 resolved cases

Office Action

§102 §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 Rejections - 35 USC § 102 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 the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action: (a)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention. Claims 1, 4, 9-12 and 20 are rejected under 35 U.S.C. 102(a)(2) as being anticipated by Andris et al. US 2022/0200467 A1. Regarding claim 20, Andris et al. disclose A power tool [0026] comprising: a motor (fig. 1, item 114); a power source interface (item 112) configured to connect to a power source (Battery); and a printed circuit board ("PCB") (fig. 3, item 300) electrically connected to the motor and the power source interface (see fig. 1 for detail) [0030], wherein the PCB includes: wide band gap ("WBG") semiconductors [0029], and a three-level or greater inverter (item 110) configured for controlling power supplied by the power source to the motor [0028, 0029], wherein a topology of the three-level or greater inverter is one of a flying capacitor multi- level ("FCML") inverter, a cascaded H-bridge inverter (semiconductor bridge), or a diode clamped inverter [0024,0025, 0031, 0034] (It should be noted that the inverter module is configured as a three-phase output). Regarding claim 1, Andris et al. disclose A power tool comprising: a motor; a power source interface configured to connect to a power source; and a printed circuit board ("PCB") electrically connected to the motor and the power source interface, the PCB including a three-level or greater inverter configured for controlling power supplied by the power source to the motor (see claim 20 rejection for detail). Regarding claim 4, Andris et al. disclose , wherein the three-level or greater inverter is a three-level inverter, a five-level inverter, a seven-level inverter, a nine-level inverter, or an eleven-level inverter (It should be noted that the inverter module is configured as a three-phase output) [0029,0031]. Regarding claim 9, Andris et al. disclose , wherein the PCB includes wide band gap ("WBG") semiconductors [0029]. Regarding claim 10, Andris et al. disclose , wherein the WBG semiconductors include Gallium Nitride ("GaN") and/or Silicon Carbide ("SiC") [0029]. Regarding claim 11, Andris et al. disclose , wherein the three-level or greater inverter is a cascaded H- bridge inverter or a diode clamped inverter (It should be noted that the inverter module is configured as a three-phase output) [0029,0031]. Regarding claim 12, Andris et al. disclose , wherein the power source is a battery pack [0025]. 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 2, 3, 5-8 and 14-19 are rejected under 35 U.S.C. 103 as being unpatentable over Andris et al. in a view of Christopher (“design and control….inverter) (IDS suppled NPL) Regarding claim 2, Andris does not disclose but Christopher discloses wherein the three-level or greater inverter is a flying capacitor multi-level ("FCML") inverter (see section 1. Background and motivation for FCML inverters). Therefore, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to use a flying capacitor multi-level ("FCML") inverter as disclosed by Christopher in Andris teachings to achieve high power density and reduce harmonic losses in the machine (Christopher’s abstract section) Regarding claim 3, Andris does not disclose but Christopher discloses wherein a switching frequency (effective switching frequency) of the three-level or greater inverter is a multiple (N-1) of a fundamental switching frequency (fsw) of the three-level or greater inverter, and a level of the three-level or greater inverter (N) is a multiplier of the fundamental switching frequency (fsw) (see section D. Inductor sizing section). Therefore, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to use a switching frequency as a multiple and a level as a multiplier as disclosed by Christopher in Andris teachings to achieve high power density (Christopher’s abstract section) Regarding claim 5, Andris does not disclose but Christopher discloses, wherein, during operation of the three-level or greater inverter, a modulation voltage between two levels is given by Vbus / (N-1), where N is a number of levels of the three-level or greater inverter (see section B. capacitance sizing). Therefore, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to use a modulation voltage as disclosed by Christopher in Andris teachings to achieve high power density (Christopher’s abstract section) Regarding claim 6, Andris does not disclose but Christopher discloses an inductor (fig. 1, item L) and a capacitor (Cout) at an output of the three-level or greater inverter (see fig. 1 for detail). Regarding claim 7, Andris does not disclose but Christopher discloses, wherein a pulse frequency seen by the inductor is given by (N-1)fsm, where fsw is a switching frequency of at least one switch of the three-level or greater inverter (see section D. inductor Sizing). Regarding claim 8, Andris and Christopher discloses, wherein an inductor ripple current of the three-level or greater inverter is defined according to ΔiL = 0.25VBus/ (N-1)2fswL, where L is the inductance of the inductor and VBUS is a bus voltage of the power tool (see section D inductor sizing) (Andris already discloses the power tool. Deff can be easily adjusted to 50% duty ratio to get 0.25. Fig. 6 shows Duty cycle reaches to 0.5 or 50%). Regarding claim 14, Andris et al. disclose A power tool [00025] comprising: a motor (fig. 1, item 114); a battery pack interface (item 112) configured to receive a battery pack (battery); a three-level or greater inverter (item 110) for controlling power supplied by the battery pack to the motor [0028, 0029], Andris does not disclose but Christopher discloses wherein a switching frequency (effective switching frequency) of the three-level or greater inverter is a multiple (N-1) of a fundamental switching frequency (fsw) of the three-level or greater inverter, and a level of the three-level or greater inverter (N) is a multiplier of the fundamental switching frequency (see section D. Inductor sizing section). Therefore, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to use a switching frequency as a multiple and a level as a multiplier as disclosed by Christopher in Andris teachings to achieve high power density (Christopher’s abstract section) Regarding claim 15, Andris et a. disclose , wherein the three-level or greater inverter is a three-level inverter, a five-level inverter, a seven-level inverter, a nine-level inverter, or an eleven-level inverter (see claim 4 rejection for detail). Regarding claim 16, Andris et al. disclose wherein, during operation of the three-level or greater inverter, a modulation voltage between two levels is given by Vbus / (N-1), where N is a number of levels (see claim 5 rejection for detail). Regarding claim 17, Andris et al. disclose : an inductor and a capacitor at an output of the three-level or greater inverter, wherein a pulse frequency seen by the inductor is given by (N-1)fsm, where fsw is a switching frequency of at least one switch of the three-level or greater inverter (see claim 7 rejection for detail). Regarding claim 18, Andris et al. disclose , wherein an inductor ripple current of the three-level or greater inverter is defined according to AiL = 0.25VBus/ (N-1)2fswL, where L is the inductance of the inductor and VBUSis a bus voltage of the power tool (see claim 8 rejection for detail). Regarding claim 19, Andris et al. disclose , wherein the three-level or greater inverter is a cascaded H- bridge inverter or a diode clamped inverter (see claim 11 rejection for detail). Claim 13 is rejected under 35 U.S.C. 103 as being unpatentable over Andris et al. in a view of White et al. US Pub. No. 2016/0020443 A1 Regarding claim 13, Andris does not disclose but White et al. disclose wherein the battery pack has a nominal voltage of greater than 50V DC [0485]. Therefore, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to use a nominal battery voltage of greater than 50V DC as disclosed by White in Andris’s teachings to operate the power tool using broader operating range (White’s paragraph 0485) Conclusion The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. LU et al. (US 2019/0238062 A1) disclose a three-level inverter. Abarzadeh et al. (US 11,456,679 B2) disclose voltage level multiplier module. YAMANAKA (JP 2006180675 A) discloses a power converter. Any inquiry concerning this communication or earlier communications from the examiner should be directed to BICKEY DHAKAL whose telephone number is (571)272-3577. The examiner can normally be reached 8:30-4:30 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, Jessica Han can be reached at 5712722078. 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. /BICKEY DHAKAL/Primary Examiner, Art Unit 2896
Read full office action

Prosecution Timeline

Jun 06, 2024
Application Filed
Feb 19, 2026
Non-Final Rejection — §102, §103 (current)

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Prosecution Projections

1-2
Expected OA Rounds
84%
Grant Probability
99%
With Interview (+16.5%)
2y 5m
Median Time to Grant
Low
PTA Risk
Based on 732 resolved cases by this examiner. Grant probability derived from career allow rate.

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