Prosecution Insights
Last updated: April 19, 2026
Application No. 18/574,854

ROTOR FOR A HIGH-SPEED ELECTRICAL MACHINE

Non-Final OA §103§112
Filed
Dec 28, 2023
Examiner
ELNAKIB, AHMED
Art Unit
2834
Tech Center
2800 — Semiconductors & Electrical Systems
Assignee
Celeroton Turbocell AG
OA Round
1 (Non-Final)
79%
Grant Probability
Favorable
1-2
OA Rounds
2y 6m
To Grant
87%
With Interview

Examiner Intelligence

Grants 79% — above average
79%
Career Allow Rate
447 granted / 568 resolved
+10.7% vs TC avg
Moderate +9% lift
Without
With
+8.7%
Interview Lift
resolved cases with interview
Typical timeline
2y 6m
Avg Prosecution
28 currently pending
Career history
596
Total Applications
across all art units

Statute-Specific Performance

§101
0.6%
-39.4% vs TC avg
§103
49.2%
+9.2% vs TC avg
§102
23.9%
-16.1% vs TC avg
§112
24.4%
-15.6% vs TC avg
Black line = Tech Center average estimate • Based on career data from 568 resolved cases

Office Action

§103 §112
DETAILED ACTION Claims 1-16 of U.S. Application No. 18574854 filed on are presented for examination. 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 . Priority Receipt is acknowledged of certified copies of papers submitted under 35 U.S.C. 119(a)-(d), which papers have been placed of record in the file. Information Disclosure Statement The information disclosure statement (IDS) submitted on 12/28/2023 is in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statement is being considered by the examiner. Claim Objections Claims 4, and 16 are objected to because of the following informalities: the recitation “CTE” should read “coefficient of thermal expansion (CTE)”. Claim 5, is objected to because of the following informalities: the recitation “HK5 or Vickers hardness” should read “Vickers hardness (HK5)”. Appropriate correction is required. 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. The term “high-speed” in claim 1 is a relative term which renders the claim indefinite. The term “high” is not defined by the claim, the specification does not provide a standard for ascertaining the requisite degree, and one of ordinary skill in the art would not be reasonably apprised of the scope of the invention. In this instance, it is not known how high the speed need to be to be considered “high” and not medium or low speed. Therefore claim 1 is rejected. Claims 2-16 are rejected for depending on claim 1. Claims 2-11, 14-16 are rejected for reciting the term “In particular”. The recitation “in particular” renders the claim indefinite because it describes a broader limitation followed by a narrow limitation. A broad range or limitation together with a narrow range or limitation that falls within the broad range or limitation (in the same claim) may be considered indefinite if the resulting claim does not clearly set forth the metes and bounds of the patent protection desired. See MPEP § 2173.05(c). The claim(s) are considered indefinite because there is a question or doubt as to whether the feature introduced by such narrower language is (a) merely exemplary of the remainder of the claim, and therefore not required, or (b) a required feature of the claims. 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 1, 3, 5, 7, 12-15 are rejected under 35 U.S.C. 103 as being unpatentable over Yamada et al. (US 2004/0051416; Hereinafter, “Yamada”) in view of Bonnefoi et al. (US 2019/0249682; Hereinafter, “Bonnefoi”). Regarding claim 1: Yamada discloses a rotor (1) for a high-speed electrical machine (para [0009]) with bearings (R, R, and T; fig. 12), the rotor (1) comprising: at least one rotor side radial bearing (R), a rotor side axial bearing (T), a rotor body (2,3,9, and 12) comprising the at least one rotor side radial bearing (R), a rotor end piece (4 that includes elements 4, and 11) comprising the rotor side axial bearing (T), wherein, when seen along the rotor's axis of rotation (center of rotor 1), a radial bearing section (where bearings R disposed) is defined as a section along which a radial bearing extends (R), wherein the rotor end piece (4) radially surrounds (as seen in fig. 1, journal member 10 radially surround connecting element 9) the rotor body (at the connecting member 9) at the interface of these two parts (fig. 1). PNG media_image1.png 267 831 media_image1.png Greyscale Yamada does not specifically disclose that the bearings are gas bearings. Bonnefoi teaches utilizing gas bearings (para [0071]). Therefore, it would have been obvious for a person having ordinary skill in the art before the effective filing date of the invention to have configured the electrical machine of Yamada with the bearings as gas bearings as disclosed by Bonnefoi since gas bearings are known for being near frictionless, high speed capability, and no need for liquid lubricants. Regarding claim 3/1: Yamada in view of Bonnefoi disclose the limitations of claim 1 and Bonnefoi further discloses that the rotor end piece (10), seen along the rotor's axis of rotation, does not substantially overlap a radial bearing section of the rotor body, in particular wherein the overlap is less than 15% or less than 10% or less than 5% of the diameter of the rotor body in the radial bearing section, or wherein there is no overlap at all (there is no axial overlap as seen in fig. 1). Regarding claim 5/1: Yamada in view of Bonnefoi disclose the limitations of claim 1 and Yamada further discloses that the rotor body material (silicon nitride of portion 3 of the shaft body; silicon nitride known to have HK5 of 15-20 GPa) has a HK5 or Vickers hardness larger than 10 GPa, in particular larger than 15 GPa, even more in particular larger than 20 GPa. Regarding claim 7/1: Yamada in view of Bonnefoi disclose the limitations of claim 1 and Yamada further discloses that when seen along the rotor's axis of rotation, an axial bearing (T) section is a section comprising the rotor side axial bearing (T), and wherein a circumferential groove (annotated fig. 1 below) is arranged between the axial bearing section (T) and a section in which the rotor end piece (10) and rotor body overlap (annotated fig. 1 below), PNG media_image2.png 426 421 media_image2.png Greyscale However Yamada in view of Bonnefoi does not specifically disclose that a radial depth of the circumferential groove is at least 30%, in particular at least 50%, in particular at least 70% of a radial thickness of an annular section of the rotor end piece where it radially surrounds the rotor body. The value of the depth of the circumferential groove a result effective variables since changing the depth of the circumferential groove affects the dimensions and integrity of the shaft end and the axial thrust bearing support assembly. Having the depth as claimed increases the fitting between the shaft end and the thrust bearing rotor support, and since Yamada in view of Bonnefoi discloses the general condition of the claim, it is within the level of ordinarily skilled artisan to find the optimum workable values of that angle (MPEP 2144.05(II).B). Consequently, it would have been obvious to a person having ordinary skill in the art before the effective filing of the claimed invention to have formed the circumferential groove of Yamada in view of Bonnefoi to be at least 30%, in particular at least 50%, in particular at least 70% of a radial thickness of an annular section of the rotor end piece where it radially surrounds the rotor body to increase the mechanical integrity of the rotor. Regarding claim 12/1: Yamada in view of Bonnefoi disclose the limitations of claim 1 and Yamada further discloses that the rotor body is a solid body (fig. 1 shows a solid/not hollow shaft). Regarding claim 13/1: Yamada in view of Bonnefoi disclose the limitations of claim 1 and Bonnefoi further discloses that the rotor body is shaped to be a hollow cylinder (fig. 1-2). Regarding claim 14/1: Yamada in view of Bonnefoi disclose the limitations of claim 1 and Yamada further discloses that the rotor (1) comprises a permanent magnet (2), and when seen along the rotor's axis of rotation, a magnet section is a section along which the permanent magnet extends (fig. 1), and wherein either the permanent magnet is arranged inside the rotor body (within sleeve 12), in particular with the magnet section being at least approximately centred between two radial bearing sections (R), or the permanent magnet is arranged at a distal end of the rotor body, opposite to the rotor end piece. Regarding claim 15/1: Yamada in view of Bonnefoi disclose the limitations of claim 1 and Yamada further discloses that the rotor body (for example, portions 9, and 3a), in a section inserted into the rotor end piece (10), has the same outer diameter as in an adjacent, proximal bearing section(3a), and the same outer diameter as in a second, distal bearing section (at the end portion 10). Claims 2, 4 are rejected under 35 U.S.C. 103 as being unpatentable over Yamada in view of Bonnefoi and in further view of Mizuhara (US 4679960; Hereinafter, “Mizuhara”). Regarding claim 2/1: Yamada in view of Bonnefoi disclose the limitations of claim 1 and Bonnefoi further discloses that the rotor body (tubular portion 5) and the rotor end piece (impeller portion 6) are joined by a press-fit (para [0091]). Yamada in view of Bonnefoi does not disclose that the press fit is a conical fit. Mizuhara teaches forming the press fit as a conical fit (fig. 1). PNG media_image3.png 263 537 media_image3.png Greyscale Therefore, it would have been obvious for a person having ordinary skill in the art before the effective filing date of the invention to have configured the electrical machine of Yamada in view of Bonnefoi with the press fit is a conical fit as disclosed by Mizuhara to allow for elastic yield of the fitted shafts. Regarding claim 4/1: Yamada in view of Bonnefoi disclose the limitations of claim 1 and Bonnefoi further discloses that the rotor body material (portion 3 of the shaft is made of silicon carbide, or silicon nitride that has CTE falls between 2.5 X 10^-6 ) and 4.2 X 10^-6) has a CTE lower than 7E-6 K^-1, in particular lower than 5E-6 K K^-1 even more in particular lower than 4E-6 K K^-1, and the rotor end piece material (9 is made of Kovar material (para [0026]) which is metal alloy) is a metal. Yamada in view of Bonnefoi does not disclose the metal is steel. Mizuhara discloses metal shaft end (12) is steel. Therefore, it would have been obvious for a person having ordinary skill in the art before the effective filing date of the invention to have configured the electrical machine of Yamada in view of Bonnefoi with the rotor end piece material is a metal, in particular a steel as disclosed by Mizuhara since steel is known for its durability, strength, and rot resistance. Claim 16 is rejected under 35 U.S.C. 103 as being unpatentable over Yamada in view of Bonnefoi and in further view of Kazutsugu et al. (US 3683248; Hereinafter, “Kazutsugu ”). Regarding claim 16/1: Yamada in view of Bonnefoi disclose the limitations of claim 1 and Yamada further discloses that the rotor end piece (10-11) comprises an axial bearing plate (11), the axial bearing plate being an annular plate and being seated on the rotor body (fig. 1), and wherein the material of the rotor body (at least portion 3 is made of silicon nitride or silicon carbide) has a CTE lower than 7E-6 K^−1, in particular lower than 5E-6 K^−1 even more in particular lower than 4E-6 K^−1, (silicon nitride that has CTE falls between 2.5 X 10^-6) and the axial bearing plate is made of a metal, in particular of a steel. Kazutsugu discloses axial bearing plate (18) is made of a metal, in particular of a steel (col. 2, lines 23-38). Therefore, it would have been obvious for a person having ordinary skill in the art before the effective filing date of the invention to have configured the electrical machine of Yamada in view of Bonnefoi with the axial bearing plate is made of a metal, in particular of a steel as disclosed by Kazutsugu since steel is known for its durability, strength, and rot resistance. Allowable Subject Matter Claims 6/2/1, 8/1, 9/8/1, 10/8/1, 11/1 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. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to AHMED ELNAKIB whose telephone number is (571)270-0638. The examiner can normally be reached 8:00AM-4:00PM. 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, Tulsidas 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. /AHMED ELNAKIB/ Primary Examiner, Art Unit 2834
Read full office action

Prosecution Timeline

Dec 28, 2023
Application Filed
Oct 30, 2025
Non-Final Rejection — §103, §112 (current)

Precedent Cases

Applications granted by this same examiner with similar technology

Patent 12601373
REFRIGERANT COMPRESSOR INCLUDING GROOVED AUXILIARY BEARING INTERFACE
2y 5m to grant Granted Apr 14, 2026
Patent 12597816
ROTOR, PERMANENT MAGNET MOTOR AND POWERTRAIN
2y 5m to grant Granted Apr 07, 2026
Patent 12584521
HYBRID AIRFOIL BEARING WITH ACTIVE DAMPING
2y 5m to grant Granted Mar 24, 2026
Patent 12587064
ELECTRIC MOTOR SYSTEM, TURBO COMPRESSOR, AND REFRIGERATION DEVICE
2y 5m to grant Granted Mar 24, 2026
Patent 12587071
DRIVE DEVICE
2y 5m to grant Granted Mar 24, 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
79%
Grant Probability
87%
With Interview (+8.7%)
2y 6m
Median Time to Grant
Low
PTA Risk
Based on 568 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