Prosecution Insights
Last updated: April 19, 2026
Application No. 18/704,451

ROTOR FOR AN EXTERNALLY EXCITED SYNCHRONOUS MACHINE

Non-Final OA §102§103§112
Filed
Apr 24, 2024
Examiner
GUGGER, SEAN A
Art Unit
2834
Tech Center
2800 — Semiconductors & Electrical Systems
Assignee
Mahle International GmbH
OA Round
1 (Non-Final)
64%
Grant Probability
Moderate
1-2
OA Rounds
2y 2m
To Grant
88%
With Interview

Examiner Intelligence

Grants 64% of resolved cases
64%
Career Allow Rate
434 granted / 677 resolved
-3.9% vs TC avg
Strong +23% interview lift
Without
With
+23.4%
Interview Lift
resolved cases with interview
Fast prosecutor
2y 2m
Avg Prosecution
41 currently pending
Career history
718
Total Applications
across all art units

Statute-Specific Performance

§101
2.2%
-37.8% vs TC avg
§103
51.1%
+11.1% vs TC avg
§102
18.0%
-22.0% vs TC avg
§112
24.7%
-15.3% vs TC avg
Black line = Tech Center average estimate • Based on career data from 677 resolved cases

Office Action

§102 §103 §112
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 § 112 The following is a quotation of 35 U.S.C. 112(b): (b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention. The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph: The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention. Claim 16 is rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention. Regarding claim 16: The last line recites “the sleeve”, there is insufficient antecedent basis for this limitation in the claim. 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 person shall be entitled to a patent unless – (a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention. Claims 1-3 and 5-11 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Trommer (US 4,603,344). Regarding claim 1: Trommer discloses a rotor for an externally excited synchronous machine (Fig. 1), comprising: rotor windings (26) arranged on a rotor shaft (10) having at least one cavity, a rectifier (24) electrically connected to the rotor windings, wherein the rectifier is at least partly arranged in the cavity of the rotor shaft (column 3, line 40). Regarding claim 2: Trommer discloses an at least partly hollow shaft end comprising an interior space is provided (allowing the rectifier assembly to fit in the shaft in Fig. 1), wherein the rectifier is arranged in the interior space of the shaft end and the shaft end is at least partly arranged in the at least one cavity of the rotor shaft (as shown in Fig. 1), or a sleeve (40, Fig. 2) is provided, wherein the rectifier is arranged in the sleeve and the sleeve is at least partly arranged in the at least one cavity of the rotor shaft (as Fig. 2 shows the rectifier assembly 24, which is all in the cavity in the shaft). Regarding claim 3: Trommer discloses the rectifier is formed as plug-in printed circuit board comprising diodes (78) arranged on one side or on both sides (inherent as they must be printed on one or both sides since those are the only options on a board). Regarding claim 5: Trommer discloses the rectifier has electrical contacts (pins 102-110) arranged on the longitudinal end side (shown in Fig. 2) for contacting with a contacting counterpiece (inherent as this is the purpose of a contact). Regarding claim 6: Trommer discloses the electrical contacts are formed as contact pins (in this case 102-110 are pins), as plug contacts or as spring contacts, and/or latching elements are provided on the rectifier and mating latching elements on the contacting counterpiece for locking together, or vice versa. Regarding claim 7: Trommer discloses an end piece or a cover (46) that fixes the rectifier. Regarding claim 8: Trommer discloses a thermally conductive and electrically insulating material (56-64, Fig. 2) arranged between the rectifier and the rotor shaft (as shown in annotated Fig. 2 below, the insulating material overhangs the rectifier diodes, going between the rectifier and the shaft). PNG media_image1.png 344 736 media_image1.png Greyscale Regarding claim 9: Trommer discloses cooling ducts (32, 34) for a coolant provided in the rotor shaft or the shaft end (in this case, oil). Regarding claim 10: Trommer discloses a fluid as coolant is applied directly to the rectifier (column 3, lines 51-53). Regarding claim 11: Trommer discloses the rectifier is arranged adjacent to an axis of rotation of the rotor shaft (in that the axis of rotation passes through the rectifier, column 4, lines 42-49). 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 12-15, 17-18, and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Trommer, in view of Box (US 2015/0333679). Regarding claim 12: Trommer discloses an externally excited synchronous machine (Fig. 1), comprising: a rotor (26, 10) that can be electrically supplied with current, the rotor including: rotor windings (26) arranged on a rotor shaft (10) having at least one cavity, a rectifier (24) electrically connected to the rotor windings, wherein the rectifier is at least partly arranged in the cavity of the rotor shaft (column 3, line 40). Trommer does not explicitly disclose a rotary transformer rotor of a rotary transformer comprising a secondary coil and a rotary transformer stator. However, Box discloses a rotary transformer rotor of a rotary transformer (paragraph 0055) comprising a secondary coil (370, Fig. 4A) and a rotary transformer stator (380). Therefore, it would have been obvious for one of ordinary skill in the art, before the effective filing date of the invention to modify the synchronous machine of Trommer to include the rotary transformer of Box in order to provide isolated power (paragraph 0032). Regarding claim 13: Trommer modified by Box discloses the rotary transformer, Box further discloses the rotary transformer stator has a primary coil (380) and a transformer core (340) of a magnetic core material (paragraph 0055). Regarding claim 14: Trommer discloses a motor comprising: a rotor (26, 10) that can be electrically supplied with current, the rotor including: rotor windings (26) arranged on a rotor shaft (10) having at least one cavity, a rectifier (24) electrically connected to the rotor windings, wherein the rectifier is at least partly arranged in the cavity of the rotor shaft (column 3, line 40). Trommer does not explicitly disclose a traction motor of a motor vehicle and a rotary transformer rotor of a rotary transformer comprising a secondary coil and a rotary transformer stator. However, Box discloses a traction motor of a motor vehicle (paragraph 0036), and a rotary transformer rotor of a rotary transformer (paragraph 0055) comprising a secondary coil (370, Fig. 4A) and a rotary transformer stator (380). Therefore, it would have been obvious for one of ordinary skill in the art, before the effective filing date of the invention to modify the synchronous machine of Trommer to include the rotary transformer of Box in order to provide isolated power (paragraph 0032). Regarding claim 15: Trommer discloses an at least partly hollow shaft end comprising an interior space is provided (allowing the rectifier assembly to fit in the shaft in Fig. 1), wherein the rectifier is arranged in the interior space of the shaft end and the shaft end is at least partly arranged in the at least one cavity of the rotor shaft (as shown in Fig. 1). Regarding claim 17: Trommer discloses a sleeve (40, Fig. 2), wherein the rectifier is arranged in the sleeve and the sleeve is at least partly arranged in the at least one cavity of the rotor shaft (as Fig. 2 is arranged in the shaft of Fig. 1). Regarding claim 18: Trommer discloses the rectifier is formed as plug-in printed circuit board comprising diodes (78) arranged on one side or on both sides (inherent as they must be printed on one or both sides since those are the only options on a board). Regarding claim 20: Trommer discloses an end piece or a cover (46) that fixes the rectifier. Allowable Subject Matter Claims 4 and 19 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. Claim 16 would be allowable if rewritten to overcome the rejection(s) under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), 2nd paragraph, set forth in this Office action and to include 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 prior art of record, alone or in combination does not explicitly teach, suggest, or render obvious, at least to the skilled artisan the rotor of claim 4, specifically comprising: longitudinal slits running in the axial direction, into which the rectifier formed as a plug-in printed circuit board is inserted and fixed, are provided in a wall of the at least one cavity, of the interior space or of the sleeve, or longitudinal openings, which run in the axial direction and which are injection-molded with plastic, are provided in a wall of the at least one cavity or of the interior space, wherein longitudinal slits running in the axial direction, into which the rectifier formed as a plug-in printed circuit board is inserted and fixed, are provided in the plastic, in the context of the other components in the claim. Claims 16 and 19 are allowable for reciting a similar limitation as claim 4. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to SEAN GUGGER whose telephone number is (571)272-5343. The examiner can normally be reached M-Th 9:00am - 5:00pm 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, T.C. Patel can be reached at 571 272 2098. 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. /SEAN GUGGER/Primary Examiner, Art Unit 2834
Read full office action

Prosecution Timeline

Apr 24, 2024
Application Filed
Jan 28, 2026
Non-Final Rejection — §102, §103, §112 (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
64%
Grant Probability
88%
With Interview (+23.4%)
2y 2m
Median Time to Grant
Low
PTA Risk
Based on 677 resolved cases by this examiner. Grant probability derived from career allow rate.

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