Prosecution Insights
Last updated: April 19, 2026
Application No. 18/238,197

MONITORING BREAKTHROUGH OF ELECTRICAL DISCHARGE MACHINING ELECTRODE THROUGH A WORKPIECE

Non-Final OA §103
Filed
Aug 25, 2023
Examiner
LISOWSKI, JACEK
Art Unit
3741
Tech Center
3700 — Mechanical Engineering & Manufacturing
Assignee
Rtx Corporation
OA Round
1 (Non-Final)
65%
Grant Probability
Favorable
1-2
OA Rounds
3y 3m
To Grant
99%
With Interview

Examiner Intelligence

Grants 65% — above average
65%
Career Allow Rate
143 granted / 219 resolved
-4.7% vs TC avg
Strong +43% interview lift
Without
With
+42.6%
Interview Lift
resolved cases with interview
Typical timeline
3y 3m
Avg Prosecution
20 currently pending
Career history
239
Total Applications
across all art units

Statute-Specific Performance

§101
0.1%
-39.9% vs TC avg
§103
56.5%
+16.5% vs TC avg
§102
14.5%
-25.5% vs TC avg
§112
26.3%
-13.7% vs TC avg
Black line = Tech Center average estimate • Based on career data from 219 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 . This is in response to the above application filed on 25 August 2023. Claims 1-20 are examined. 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 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. The factual inquiries set forth in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), that are applied 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. Claims 17-19 are rejected under 35 U.S.C. 103 as being unpatentable over Grotenhuis 9346113 in view of Li 2010/0051588, and further in view of Inoue 4393292. Regarding Claim 17, Grotenhuis teaches a manufacturing method (Fig. 3), comprising: electrical discharge machining 110 a workpiece WP using an electrode 112 to form an aperture (hole) in the workpiece WP, the workpiece WP extending between a face surface [a] and a back surface [b] (Annotated Fig. 4, below), measuring an EDM voltage (measures the voltage between the electrode and the workpiece) indicative of a gap voltage (gap voltage) between the electrode 112 and the workpiece WP using a measurement device 124 to provide an EDM voltage measurement signal (measured gap voltage as input – this reads as a measurement signal) indicative of the EDM voltage (gap voltage) (Col. 2, l. 50 – Col. 3, l. 12, Col. 3, ll. 24-36, and Col. 3, ll. 44-59; Figs. 3-4. Annotated Fig. 4, below). PNG media_image1.png 847 751 media_image1.png Greyscale Figure A: Annotated Fig. 4 of Grotenhuis (U.S. 9346113) Grotenhuis does not teach the electrical discharge machining comprising plunging the electrode into the workpiece through the face surface, and determining whether the electrode has broken through the back surface using the EDM voltage measurement signal. Li teaches a similar manufacturing method comprising an electrical discharge machining 10, controller 14, and the electrical discharge machining 10 comprising plunging the electrode 11 into the workpiece through the face surface 102 (seen in Fig. 2a-2c) ([0021; 0026-29]; Figs. 2a-c). determining (via controller 14, modules 140-142) whether the electrode 11 has broken (breakthrough stage) through the back surface (seen in Fig. 2c) using the EDM voltage measurement signal (sent signals …from element 16, voltage detection) ([0016-17; 0021, 0026-29]; Figs. 1 & 2a-c). It would have been obvious to one of ordinary skill in the art before the effective filling date of the claimed invention to modify the electrical discharge machining 110 and the electrode 112 of Grotenhuis to include Li’s electrode 11 and plunge the electrode 11 into the workpiece through the face surface 102, as taught by Li, because it has been held that a simple substitution of one known element, in this case, electrode 112 of Grotenhuis, for another, in this case, electrode 11 of Li, to obtain predictable results, in this case, machining holes in a workpiece, is an obvious extension of prior art teachings, KSR INT’L CO. V. TELEFLEX. Additionally, it would have been obvious to one of ordinary skill in the art before the effective filling date of the claimed invention to provide the controller 130 of Grotenhuis to include the controller 14, comprising modules 140-142, for determining whether the electrode 11 has broken (breakthrough stage) through the back surface using the measurement signal (sent signals …from element 16, voltage detection), as taught by Li, in order to end the machining upon completion of the breakthrough stage, thereby avoiding having the electrode damage other structures of the workpiece so as to improve the machining quality (Li [0028]). Grotenhuis in view of Li does not teach using a high frequency measurement device to provide an EDM voltage measurement signal indicative of the EDM voltage, the EDM voltage is measured by the high frequency measurement device at a measurement frequency equal to or greater than ten kilohertz. Inoue teaches a similar electrical discharge machining (EDM) method and using a high frequency measurement device 104 to provide an EDM voltage measurement signal (a vibration [signal]) indicative of the EDM voltage (volage across the gap G, in Col. 9, ll. 37-67), the EDM voltage (volage across the gap G) is measured by the high frequency measurement device 104 at a measurement frequency equal to or greater than ten kilohertz (vibration of a frequency in the range between 1 and 500 kHz) (Col. 9, ll. 37-67, and Col. 12, ll. 38-57; Fig. 15). It would have been obvious to one of ordinary skill in the art before the effective filling date of the claimed invention to provide the measurement device 124 of Grotenhuis in view of Li to include a high frequency measurement device 104 that measures the EDM voltage (volage across the gap G) at a measurement frequency equal to or greater than ten kilohertz (vibration of a frequency in the range between 1 and 500 kHz), as taught by Inoue, in order to “promote the removal of machining products from the region of the machining gap G while promptly extinguishing an arc discharge or short-circuiting as it occurs between the tool electrode 101 and the workpiece 111, thus permitting machining discharges to be repetitively produced through the gap G with an enhanced stability” (Inoue, Col. 9, ll. 37-67) and to select the correct vibration for the electrode for a particular machining purpose (Inoue, Col. 12, ll. 38-57). While Grotenhuis in view of Li and Inoue teaches an apparatus, if a prior art device, in its normal and usual operation, would necessarily perform the method claimed, then the method claimed will be considered an obvious extension of prior art teachings. Regarding Claim 18, Grotenhuis in view of Li and Inoue teaches the method as claimed and as discussed above for claim 17, and Grotenhuis further teaches measuring an EDM voltage (measures the voltage between the electrode and the workpiece) indicative of a gap voltage (gap voltage) between the electrode 112 and the workpiece WP using a measurement device 124 to provide an EDM voltage measurement signal (measured gap voltage as input – this reads as a measurement signal) indicative of the EDM voltage (gap voltage) (Col. 2, l. 50 – Col. 3, l. 12, Col. 3, ll. 24-36, and Col. 3, ll. 44-59; Figs. 3-4. Annotated Fig. 4, below). PNG media_image1.png 847 751 media_image1.png Greyscale Figure A: Annotated Fig. 4 of Grotenhuis (U.S. 9346113) Grotenhuis in view of Li and Inoue, as discussed so far, does not teach using a low frequency measurement device to provide an EDM system voltage measurement signal indicative of the gap voltage, the EDM system voltage is measured by the low frequency measurement device at a measurement frequency equal to or less than five-hundred hertz; and controlling movement of the electrode using the EDM system measurement signal. Inoue further teaches using a low frequency measurement device 170 to provide an EDM system voltage measurement signal (a vibration [signal]) indicative of the gap voltage (volage across the gap G, in Col. 9, ll. 37-67), the EDM system voltage (volage across the gap G) is measured by the low frequency measurement device at a measurement frequency equal to or less than five-hundred hertz (vibration of a frequency in the range between 50 and 500 Hz) (Col. 12, ll. 38-57; Fig. 15).; and controlling movement (inherent – the signal from the low frequency measurement device 170 is applied to electrode 101. Therefore, inherently the signal is used to control the movement of the electrode, as claimed) of the electrode 101 using the EDM system measurement signal (a vibration [signal]) (Col. 9, ll. 37-67, and Col. 12, ll. 38-57; Fig. 15). It would have been obvious to one of ordinary skill in the art before the effective filling date of the claimed invention to provide the measurement device 124 of Grotenhuis in view of Li and Inoue to include a low frequency measurement device 170 that provides an EDM system voltage measurement signal (a vibration [signal]) indicative of the gap voltage (volage across the gap G), the EDM system voltage (volage across the gap G) is measured by the low frequency measurement device at a measurement frequency equal to or less than five-hundred hertz (vibration of a frequency in the range between 50 and 500 Hz), and control the movement (inherent – the signal from the low frequency measurement device 170 is applied to electrode 101. Therefore, inherently the signal is used to control the movement of the electrode, as claimed) of the electrode 101 using the EDM system measurement signal (a vibration [signal]), as taught by Inoue, for the same reason as discussed in rejection of claim 17 above. While Grotenhuis in view of Li and Inoue teaches an apparatus, if a prior art device, in its normal and usual operation, would necessarily perform the method claimed, then the method claimed will be considered an obvious extension of prior art teachings. Regarding Claim 19, Grotenhuis in view of Li and Inoue teaches the method as claimed and as discussed above for claim 17. However, Grotenhuis in view of Li and Inoue, as discussed so far, does not teach the determining of whether the electrode has broken through the back surface is performed during the electrical discharge machining; and the electrical discharge machining is terminated when it is determined that the electrode has completely broken through the back surface. Li further teaches the determining (via controller 14, modules 140-142) of whether the electrode 11 has broken (breakthrough stage) through the back surface (seen in Fig. 2c) is performed during the electrical discharge machining (during the machining; breakthrough stage begins … detection elements 16-18 detect and send signals to controller 14 for processing) ([0015-17; 0021, 0027-29]); and the electrical discharge machining 10 is terminated (end the machining upon completion of the breakthrough stage) when it is determined that the electrode 11 has completely broken (breakthrough stage) through the back surface (seen in Fig. 2c) ([0016-17; 0021, 0026-29]; Figs. 1 & 2a-c). It would have been obvious to one of ordinary skill in the art before the effective filling date of the claimed invention to provide the controller 130 of Grotenhuis in view of Li and Inoue to include controller 14, comprising modules 140-142, for determining (via controller 14, modules 140-142) of whether the electrode 11 has broken (breakthrough stage) through the back surface is performed during the electrical discharge machining (during the machining; breakthrough stage begins … detection elements 16-18 detect and send signals to controller 14 for processing); and have the electrical discharge machining 10 be terminated (end the machining upon completion of the breakthrough stage) when it is determined that the electrode 11 has completely broken (breakthrough stage) through the back surface , as taught by Li, in order to end the machining upon completion of the breakthrough stage, thereby avoiding having the electrode damage other structures of the workpiece so as to improve the machining quality (Li [0028]). Claim 20 is rejected under 35 U.S.C. 103 as being unpatentable over Grotenhuis in view of Li. Regarding Claim 20, Grotenhuis teaches a manufacturing method (Fig. 3), comprising: electrical discharge machining 110 a workpiece WP using an electrode 112 to form an aperture (hole) in the workpiece WP, the workpiece WP extending between a face surface [a] and a back surface [b] (Annotated Fig. 4, below), the workpiece WP secured to a support 116 by a fixture [c] (Annotated Fig. 4, below), and the electrode 112 supported by and electrically coupled to a guide 114; measuring a measurement voltage between the guide 114 and the fixture [c] indicative of a gap voltage between the electrode 112 and the workpiece WP (measures the voltage between the electrode and the workpiece) using a measurement device 124 to provide a measurement signal (measured gap voltage as input – this reads as a measurement signal) indicative of the measurement voltage (gap voltage), the measurement device 124 electrically coupled to the guide 114 and the fixture [c] (Col. 2, l. 50 – Col. 3, l. 12, Col. 3, ll. 24-36, and Col. 3, ll. 44-59; Figs. 3-4. Annotated Fig. 4, below). PNG media_image1.png 847 751 media_image1.png Greyscale Figure A: Annotated Fig. 4 of Grotenhuis (U.S. 9346113) Grotenhuis further comprises a controller 130 that operatively is connected and controls the movement of the electrical discharge machining 110, including the electrode 112 and the support 116 (Col. 3, ll. 24-36; Figs. 3-4). Grotenhuis does not teach the electrical discharge machining comprising plunging the electrode into the workpiece through the face surface, and determining whether the electrode has broken through the back surface using the measurement signal. Li teaches a similar manufacturing method comprising an electrical discharge machining 10, controller 14, and the electrical discharge machining 10 comprising plunging the electrode 11 into the workpiece through the face surface 102 (seen in Fig. 2a-2c) ([0021; 0026-29]; Figs. 2a-c). determining (via controller 14, modules 140-142) whether the electrode 11 has broken (breakthrough stage) through the back surface (seen in Fig. 2c) using the measurement signal (sent signals …from element 16, voltage detection) ([0016-17; 0021, 0026-29]; Figs. 1 & 2a-c). It would have been obvious to one of ordinary skill in the art before the effective filling date of the claimed invention to modify the electrical discharge machining 110 and the electrode 112 of Grotenhuis to include Li’s electrode 11 and plunge the electrode 11 into the workpiece through the face surface 102, as taught by Li, because it has been held that a simple substitution of one known element, in this case, electrode 112 of Grotenhuis, for another, in this case, electrode 11 of Li, to obtain predictable results, in this case, machining holes in a workpiece, is an obvious extension of prior art teachings, KSR INT’L CO. V. TELEFLEX. Additionally, it would have been obvious to one of ordinary skill in the art before the effective filling date of the claimed invention to provide the controller 130 of Grotenhuis to include the controller 14, comprising modules 140-142, for determining whether the electrode 11 has broken (breakthrough stage) through the back surface using the measurement signal (sent signals …from element 16, voltage detection), as taught by Li, in order to end the machining upon completion of the breakthrough stage, thereby avoiding having the electrode damage other structures of the workpiece so as to improve the machining quality (Li [0028]). While Grotenhuis in view of Li teaches an apparatus, if a prior art device, in its normal and usual operation, would necessarily perform the method claimed, then the method claimed will be considered an obvious extension of prior art teachings. Allowable Subject Matter Claims 1-16 are allowed. The following is an examiner’s statement of reasons for allowance: Prior art does not teach or fairly suggest, either by itself or in combination with other prior art, and in combination with the other limitations of the independent claim 1, “measuring a first voltage indicative of a gap voltage between the electrode and the workpiece using a first measurement device to provide a first measurement signal indicative of the first voltage; controlling movement of the electrode using the first measurement signal; measuring a second voltage indicative of the gap voltage using a second measurement device to provide a second measurement signal indicative of the second voltage; and determining whether the electrode has broken through the workpiece using the second measurement signal.” disclosed in the specification [0062-65] and Fig. 6. Prior art of Li 2010/0051588 teaches electrical discharge machining with only one voltage measurement device. Closest prior art of Katogi 2017/0259362 teaches (in [0024]; Fig. 1) one detection circuit connected to two lines. Closest prior art of Furuta 11135668 teaches (in Fig. 2) two voltage circuits54, 56 with one voltage detector. Closest prior art of Yamada 2015/0246403 ([0021-22]; Fig. 1) teaches a gap current detector 14 and a voltage gap detector 13. However, Grotenhuis, Li, Inoue, Katogi, Furuta, or Yamada does not teach either by itself or in combination with other prior art, the above limitations of independent claim 1. 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 Any inquiry concerning this communication or earlier communications from the examiner should be directed to JACEK LISOWSKI whose telephone number is (408) 918-7635. The examiner can normally be reached on Monday - Friday 10 am - 6 pm PST. 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, Phutthiwat Wongwian can be reached on (571) 270-5426. 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. /JACEK LISOWSKI/Examiner, Art Unit 3741 /PHUTTHIWAT WONGWIAN/Supervisory Patent Examiner, Art Unit 3741
Read full office action

Prosecution Timeline

Aug 25, 2023
Application Filed
Feb 20, 2026
Non-Final Rejection — §103 (current)

Precedent Cases

Applications granted by this same examiner with similar technology

Patent 12595762
GAS TURBINE ENGINE WITH BLEED DIFFUSER BAFFLES
2y 5m to grant Granted Apr 07, 2026
Patent 12595765
BIFURCATION INTEGRATED ELECTRICAL SYSTEM FOR HYBRID AIRCRAFT PROPULSION SYSTEM
2y 5m to grant Granted Apr 07, 2026
Patent 12590546
ENGINE COMPONENT ASSEMBLY WITH A COOLING APERTURE
2y 5m to grant Granted Mar 31, 2026
Patent 12584414
GAS TURBINE ENGINE WITH COMPOSITE AIRFOIL AND PREFORM CORE
2y 5m to grant Granted Mar 24, 2026
Patent 12565854
HYBRID PROPULSION TURBOPROP ENGINE COUPLED TO A PROPELLER AND AIRCRAFT COMPRISING SUCH A TURBOPROP ENGINE
2y 5m to grant Granted Mar 03, 2026
Study what changed to get past this examiner. Based on 5 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
65%
Grant Probability
99%
With Interview (+42.6%)
3y 3m
Median Time to Grant
Low
PTA Risk
Based on 219 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