Prosecution Insights
Last updated: April 18, 2026
Application No. 17/937,084

PULSED ELECTROCHEMICAL MACHINING

Non-Final OA §103§DP
Filed
Sep 30, 2022
Examiner
COHEN, BRIAN W
Art Unit
1759
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Rolls-Royce
OA Round
3 (Non-Final)
54%
Grant Probability
Moderate
3-4
OA Rounds
3y 1m
To Grant
99%
With Interview

Examiner Intelligence

Grants 54% of resolved cases
54%
Career Allow Rate
343 granted / 633 resolved
-10.8% vs TC avg
Strong +47% interview lift
Without
With
+46.9%
Interview Lift
resolved cases with interview
Typical timeline
3y 1m
Avg Prosecution
28 currently pending
Career history
661
Total Applications
across all art units

Statute-Specific Performance

§101
0.3%
-39.7% vs TC avg
§103
53.7%
+13.7% vs TC avg
§102
17.5%
-22.5% vs TC avg
§112
22.0%
-18.0% vs TC avg
Black line = Tech Center average estimate • Based on career data from 633 resolved cases

Office Action

§103 §DP
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 . Continued Examination Under 37 CFR 1.114 A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 11/12/2025 has been entered. Response to Amendment The amendment filed on 11/12/2025 has been entered into the prosecution for the application. Currently claims 1-17 and 19-21 are pending with claims 15-17 and 20 withdrawn from consideration. Claims 1-14 and 21 are pending examination. 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 non-obviousness. Claims 1-9 and 21 are rejected under 35 U.S.C. 103 as being unpatentable over US 2023/0066556 of Herrington et al in view of US 10,730,125 of Forenz et al and US 3,421,997 of Williams. It is noted that Herrington is a CON of PCT/US21/28895 (which was filed on 4/23/21 and published on 12/2/2021) as well as provisional application 63/015419 which was filed on 4/24/2020 and fully supports the non-provisional application. As to claim 1, Herrington teaches of a method for pulsed electrochemical machining of a workpiece (Herrington, [0003] and [0048]), the method comprising: generating a pulsed current between an electrode of a tool body of a pECM machining assembly and the workpiece, the tool body defining a tool axis, and the electrode comprising an electrically conductive material and defining a working surface at a first end configured to face the workpiece (Herrington, [0040], [0044], [0048], [0053] – [0055], and Figs. 2A and 4); delivering an electrolyte through a plurality of apertures in the working surface into an interelectrode gap between the working surface of electrode and a target surface of the workpiece, wherein the plurality of apertures fluidically couple to an electrolyte system (Herrington, [0040], [0048], [0053] – [0055], [0071] and Figs. 2A, 4 and 14); and positioning the working surface of the electrode relative to the target surface of the workpiece to remove material from the target surface of the workpiece (Herrington, [0040], [0048], [0053] – [0055], [0071] and Figs. 2A, 4 and 14). Herrington additionally teaches that the electrolyte flows to the holes from a single manifold (i.e. manifold block of the tool body) to the working surface of the electrode (Herrington, [0034], [0040] and Fig. 2A). PNG media_image1.png 836 678 media_image1.png Greyscale PNG media_image2.png 776 692 media_image2.png Greyscale As seen in Figs. 4 and 2A, the tool body includes a tool axis, the electrode comprises a conductive material and defines a working surface of the electrode (202) to face the workpiece (220). As seen the electrolyte (216) is delivered to the interelectrode gap (218) from the plurality of apertures (210) of the electrode to the target surface of the workpiece for material removal. As in Fig. 14, the apertures are fluidically coupled to an electrolyte system (1402). Herrington does not specifically teach the pulsed current is supplied by a pulsed direct current. Herrington also does not teach the baffle element. Forenz teaches of electrochemical machining processes (Forenz, col 1 lines 61-65). Forenz additionally teaches that known methods of pulse machining include utilizing a pulsed direct current source to control the pulsed current which allows for machining during the pulse on time (Forenz, col 8 lines 49-67). As Herrington teaches utilizing a pulsed current (Herrington, [0048]), it would have been obvious to a person before the effective filing date of the claimed invention to modify Herrington as per Forenz so as to specifically utilize a pulsed direct current source for supplying the pulsed current in performing the electrochemical machining process as desired. As modified, Herrington in view of Forenz do not teach the baffle element. Williams teaches to electrochemical machining of a metal workpiece (Williams, col 1 lines 19-42, col 1 line 54 thru col 2 line 15). Williams additionally teaches that the electrolyte flow from a manifold block (343) through a baffle element defining a reservoir (355) which at least partially equalizes electrolyte pressure above a plurality of baffle element apertures (353) to deliver the electrolyte through the electrode to the target surface of the workpiece (Williams, col 18 lines 24-38 and Figs. 29 and 31). As seen in Figs. 29 and 31, below, the cavity (347) within the electrode block (343) defines the manifold block. The electrolyte flows through holes (345) of the electrode assembly to the target surface of the workpiece. The holes (353) extend partway up the block where their upper ends are connected (i.e. forming a reservoir) with transversely extending manifolding passages (355) which reduce and tend to equalize the pressure drop for all the holes (353). PNG media_image3.png 328 322 media_image3.png Greyscale PNG media_image4.png 298 466 media_image4.png Greyscale Therefore it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to modify Herrington in view of Forenz as per Williams so as to utilize the desired baffle elements in order to reduce and equalize the pressure drop of the electrolyte within the tool body. As to claims 2 and 3, Herrington in view of Forenz and Williams teach to the method of claim 1. Herrington additionally teaches the electrode defines a first end defined by the working surface and a second end, such that each aperture corresponds to a channel extending from the first end through the electrode to the second end and such that each channel can deliver electrolyte to the interelectrode gap (Herrington, [0043], [0054] and Figs. 3A and 5). PNG media_image5.png 662 694 media_image5.png Greyscale PNG media_image6.png 642 678 media_image6.png Greyscale As seen in Fig. 3A and 5, the electrode includes channels (510) from a second end of the electrode (514 side) to the first end of the electrode (502) towards the working surface such that electrolyte is delivered to the working surface of the electrode through the channels within the electrode. As to claims 4 and 5, Herrington in view of Forenz and Williams teach to the method of claim 1. Herrington additionally teaches a channel within the electrode is fluidically coupled to the manifold to an inlet of the electrode, thus to an electrolyte inlet and outlet of the manifold block (Herrington, [0034], [0040] and Fig. 4). As to claims 6-8, Herrington in view of Forenz and Williams teach to the method of claim 1. Herrington additionally teaches the electrode comprises a metal such that the electrode can be fully formed by additive manufacturing as a single piece (Herrington, [0035] and [0044]). As to claim 9, Herrington in view of Forenz and Williams teaches to the method of claim 1. Herrington additionally teaches and apertures are evenly distributed across the workpiece such that electrolyte is distributed through the apertures of the electrode (Herrington, [0068], [0071] and Figs. 12 and Fig. 14). Herrington does not teach the baffle element. Williams teaches to electrochemical machining of a metal workpiece (Williams, col 1 lines 19-42, col 1 line 54 thru col 2 line 15). Williams additionally teaches that the electrolyte flow from a manifold block (343) through a baffle element which at least partially equalizes electrolyte pressure above a plurality of baffle element apertures (353) to uniformly deliver the electrolyte through the electrode to the target surface of the workpiece (Williams, col 18 lines 24-38 and Figs. 29 and 31). Therefore it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to modify Herrington in view of Forenz as per Williams so as to utilize the baffle element for equalization of the pressure of the electrolyte within the system in order to facilitate uniform electrolyte flow to the target surface of the workpiece. As to claim 21, Herrington in view of Forenz and Williams teaches to the method of claim 1. Herrington in view of Forenz do not teach the baffle element. Williams teaches to electrochemical machining of a metal workpiece (Williams, col 1 lines 19-42, col 1 line 54 thru col 2 line 15). Williams additionally provides that the manifold block provides a seal around the perimeter of the baffle elements to reduce and contain leakage of the electrolyte from the electrolyte manifold to the target surface of the workpiece (Williams, col 18 lines 25-43). PNG media_image7.png 298 466 media_image7.png Greyscale Therefore it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to modify Herrington in view of Forenz as per Williams to provide a seal between the elements to facilitate movement of the electrolyte in the desired direction while minimizing leakage within the system. Claim 13 is rejected under 35 U.S.C. 103 as being unpatentable over Herrington in view of Forenz and Williams as applied to claim 1 above, and further in view of US 8,597,489 of Luo et al. As to claim 13, Herrington in view of Forenz and Williams teach to the method of claim 1. Herrington in view of Forenz and Williams do not teach forming a seal between the tool body and a flow block. Luo teaches of electrochemical machining processes and the tool electrode utilized therein (Luo, col 2 lines 8-11). Luo additionally teaches utilizing spacers, a flexible elastomeric backing and insulation to seal and thus prevent electrolyte leaks as well as facilitate the desired flow of the electrolyte in relation to the component being electrochemically machined (Luo, col 9 lines 1-20, col 15 lines 34-61 and Figs. 5, 12a and 12b). Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to modify Herrington in view of Forenz and Williams as per Luo so as to utilize a sealing mechanism between the tool body and machining surface to facilitate electrolyte flow while preventing undesired leaks. Claim 14 is rejected under 35 U.S.C. 103 as being unpatentable over Herrington in view of Forenz and Williams as applied to claim 1 above, and further in view of Wang et al “Electrochemical drilling with vacuum extraction of electrolyte” Journal of Materials Processing Technology, 210 (2010), p. 238-244. As to claim 14, Herrington in view of Forenz and Williams teaches to the method of claim 1. Herrington and Forenz and Williams do not teach pulling a vacuum through a channel in the electrode. Wang teaches of electrochemical machining (Wang, p. 238 Introduction). Wang additionally teaches the use of a vacuum through a channel within the electrode improves removal of products and the overall flow rate of the electrolyte at the working surface (Wang, p. 244 Conclusion). Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to modify Herrington in view of Forenz and Williams as per Wang so as to pull a vacuum within a channel of the electrode to improve product removal and flow rate of the electrolyte at the working surface of the electrode during the electrochemical machining process. Double Patenting The nonstatutory double patenting rejection is based on a judicially created doctrine grounded in public policy (a policy reflected in the statute) so as to prevent the unjustified or improper timewise extension of the “right to exclude” granted by a patent and to prevent possible harassment by multiple assignees. A nonstatutory double patenting rejection is appropriate where the conflicting claims are not identical, but at least one examined application claim is not patentably distinct from the reference claim(s) because the examined application claim is either anticipated by, or would have been obvious over, the reference claim(s). See, e.g., In re Berg, 140 F.3d 1428, 46 USPQ2d 1226 (Fed. Cir. 1998); In re Goodman, 11 F.3d 1046, 29 USPQ2d 2010 (Fed. Cir. 1993); In re Longi, 759 F.2d 887, 225 USPQ 645 (Fed. Cir. 1985); In re Van Ornum, 686 F.2d 937, 214 USPQ 761 (CCPA 1982); In re Vogel, 422 F.2d 438, 164 USPQ 619 (CCPA 1970); In re Thorington, 418 F.2d 528, 163 USPQ 644 (CCPA 1969). A timely filed terminal disclaimer in compliance with 37 CFR 1.321(c) or 1.321(d) may be used to overcome an actual or provisional rejection based on nonstatutory double patenting provided the reference application or patent either is shown to be commonly owned with the examined application, or claims an invention made as a result of activities undertaken within the scope of a joint research agreement. See MPEP § 717.02 for applications subject to examination under the first inventor to file provisions of the AIA as explained in MPEP § 2159. See MPEP § 2146 et seq. for applications not subject to examination under the first inventor to file provisions of the AIA . A terminal disclaimer must be signed in compliance with 37 CFR 1.321(b). The filing of a terminal disclaimer by itself is not a complete reply to a nonstatutory double patenting (NSDP) rejection. A complete reply requires that the terminal disclaimer be accompanied by a reply requesting reconsideration of the prior Office action. Even where the NSDP rejection is provisional the reply must be complete. See MPEP § 804, subsection I.B.1. For a reply to a non-final Office action, see 37 CFR 1.111(a). For a reply to final Office action, see 37 CFR 1.113(c). A request for reconsideration while not provided for in 37 CFR 1.113(c) may be filed after final for consideration. See MPEP §§ 706.07(e) and 714.13. The USPTO Internet website contains terminal disclaimer forms which may be used. Please visit www.uspto.gov/patent/patents-forms. The actual filing date of the application in which the form is filed determines what form (e.g., PTO/SB/25, PTO/SB/26, PTO/AIA /25, or PTO/AIA /26) should be used. A web-based eTerminal Disclaimer may be filled out completely online using web-screens. An eTerminal Disclaimer that meets all requirements is auto-processed and approved immediately upon submission. For more information about eTerminal Disclaimers, refer to www.uspto.gov/patents/apply/applying-online/eterminal-disclaimer. Claims 10-12 are rejected on the ground of nonstatutory double patenting as being unpatentable over claims 16-18 of U.S. Patent No. 12,447,543 of Garner et al in view of 3,421,997 of Williams. As to claims 10-12 of the current application, claim 16 of Garner teaches the method of pulsed electrochemical machining with the same context of electrode, tool body and apertures. Garner does not specifically claim the baffle assembly, however, this is obvious in view of Williams. In specific to the electrolyte flow dynamics and area per unit of claims 10-12, these are the same as those described in claim 16 of Garner. Allowable Subject Matter Claims 10-12 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: The limitations defining the cross section area of central vs. perimeter portions as they relate to electrolyte flow overcomes the closest art of record. With that said, as noted above, a terminal disclaimer must be filed in relation to US 12,447,543. While not identical, claims 10-12 are substantial duplicates of claims 16-18 of Garner such that that same and overlapping subject matter is claimed. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to BRIAN W COHEN whose telephone number is (571)270-7961. The examiner can normally be reached M-F: 9 am to 5 pm EST. 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, Duane Smith can be reached at 571-272-1166. 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. BRIAN W. COHEN Primary Examiner Art Unit 1759 /BRIAN W COHEN/ Primary Examiner, Art Unit 1759
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Prosecution Timeline

Sep 30, 2022
Application Filed
Apr 01, 2025
Non-Final Rejection — §103, §DP
May 06, 2025
Interview Requested
May 14, 2025
Examiner Interview Summary
May 14, 2025
Applicant Interview (Telephonic)
Jul 02, 2025
Response Filed
Aug 08, 2025
Final Rejection — §103, §DP
Oct 14, 2025
Response after Non-Final Action
Nov 12, 2025
Request for Continued Examination
Nov 15, 2025
Response after Non-Final Action
Dec 17, 2025
Non-Final Rejection — §103, §DP
Mar 11, 2026
Interview Requested
Mar 17, 2026
Applicant Interview (Telephonic)
Mar 17, 2026
Examiner Interview Summary
Mar 19, 2026
Response Filed

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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
54%
Grant Probability
99%
With Interview (+46.9%)
3y 1m
Median Time to Grant
High
PTA Risk
Based on 633 resolved cases by this examiner. Grant probability derived from career allow rate.

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