Office Action Predictor
Application No. 18/532,196

ELECTRICAL MACHINE HAVING STATOR SLEEVE

Non-Final OA §103
Filed
Dec 07, 2023
Examiner
DESAI, NAISHADH N
Art Unit
2834
Tech Center
2800 — Semiconductors & Electrical Systems
Assignee
Rolls-Royce PLC
OA Round
1 (Non-Final)
82%
Grant Probability
Favorable
1-2
OA Rounds
2y 7m
To Grant
91%
With Interview

Examiner Intelligence

82%
Career Allow Rate
891 granted / 1089 resolved
Without
With
+8.8%
Interview Lift
avg trend
2y 7m
Avg Prosecution
30 pending
1119
Total Applications
career history

Statute-Specific Performance

§101
0.6%
-39.4% vs TC avg
§103
54.8%
+14.8% vs TC avg
§102
28.9%
-11.1% vs TC avg
§112
14.2%
-25.8% vs TC avg
Black line = Tech Center average estimate • Based on career data

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 . Priority Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55. Information Disclosure Statement The information disclosure statements (IDS’s) submitted on 12/07/2023 and 08/26/2024 are in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statements have been considered by the examiner. 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 nonobviousness. Claim(s) 1-4, 16-19 are rejected under 35 U.S.C. 103 as being unpatentable over Roesel et al. (US 4600873) in view of Chong et al. (GB 2509738). Regarding claim 1, Roesel et al. teach: An electrical machine (title) comprising: a rotor (230, Fig 7) at least partially disposed within a rotor chamber (inside 202), a stator core (206) coaxially arranged with the rotor chamber (inside 202), and a stator sleeve (220), wherein the stator sleeve (220) is annular and is positioned between the stator core (206) and the rotor chamber (inside 202). Roesel et al. do not explicitly teach wherein the stator sleeve comprises a magnetic material having a relative permeability of at least 10 and an intrinsic coercivity no greater than 1 kAm.−1. However, Roesel et al. teaches the use of materials with relatively high permeability and conductivity, in order to achieve low eddy currents (C3 ll 59-68). Chong et al. discloses an apparatus having a stator sleeve (40,80, abstract) for the purpose of withstanding fluid pressures and based on desired electromagnetic performance (page 8 ll 30- page 9 line 5). Chong et al. do not explicitly mention wherein the stator sleeve comprises a magnetic material having a relative permeability of at least 10 and an intrinsic coercivity no greater than 1 kAm.−1. However, a skilled artisan would readily recognize the benefits of combining the teachings of Roesel et al. in view of Chong et al. to have make a machine wherein the stator sleeve comprises a magnetic material having a relative permeability of at least 10 and an intrinsic coercivity no greater than 1 kAm.−1, since it would depend on cost, weight and desired electromagnetic performance (page 8 ll 30- page 9 line 5 of Ching et al.) and desired levels of a high permeability, low eddy current and high electrical conductivity (abstract of Roesel et al.). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing of the invention to modify Roesel et al. in view of Chong et al. wherein the stator sleeve comprises a magnetic material having a relative permeability of at least 10 and an intrinsic coercivity no greater than 1 kAm.−1. The motivation to do so would depend on cost, weight and desired electromagnetic performance (page 8 ll 30- page 9 line 5 of Chong et al.) and desired levels of a high permeability, low eddy current and high electrical conductivity, cost,power (abstract, C2 ll 5-63 of Roesel et al.). Regarding claims 2-4, Roesel et al. in view of Chong et al. disclose the invention as discussed above, except wherein the magnetic material comprises iron or iron-cobalt alloy or at least one of nickel or a nickel-iron alloy. However, a skilled artisan would readily recognize the benefits of combining the teachings of Roesel et al. in view of Chong et al. to choose a material wherein the magnetic material comprises iron or iron-cobalt alloy or at least one of nickel or a nickel-iron alloy, since it would depend on cost, weight and desired electromagnetic performance (page 8 ll 30- page 9 line 5 of Ching et al.) and desired levels of a high permeability, low eddy current and high electrical conductivity, cost, power (abstract, C2 ll 5-63 of Roesel et al.). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing of the invention to modify Roesel et al. in view of Chong et al. wherein the magnetic material comprises iron or iron-cobalt alloy or at least one of nickel or a nickel-iron alloy. The motivation to do so would depend on cost, weight and desired electromagnetic performance (page 8 ll 30- page 9 line 5 of Ching et al.) and desired levels of a high permeability, low eddy current and high electrical conductivity, cost,power (abstract, C2 ll 5-63 of Roesel et al.). Roesel et al. in view of Chong et al. discloses the claimed invention except for wherein the magnetic material comprises iron or iron-cobalt alloy or at least one of nickel or a nickel-iron alloy. It would have been obvious to one having ordinary skill in the art before the effective filing of the invention to wherein the magnetic material comprises iron or iron-cobalt alloy or at least one of nickel or a nickel-iron alloy, since it has been held to be within the general skill of a worker in the art to select a known material on the basis of its suitability for the intended use as a matter of obvious design choice. In re Leshin, 125 USPQ 416 The motivation to do so would depend on cost, weight and desired electromagnetic performance (page 8 ll 30- page 9 line 5 of Ching et al.) and desired levels of a high permeability, low eddy current and high electrical conductivity, cost,power (abstract, C2 ll 5-63 of Roesel et al.). Regarding claim 16/1, Roesel et al. teaches the invention as discussed above, except wherein the stator sleeve provides a fluid seal between the rotor chamber and the stator core. Chong et al. teach wherein the stator sleeve provides a fluid seal between the rotor chamber and the stator core (Page 5 ll 1-7). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing of the invention to modify Roesel in view of Chong et al. wherein the stator sleeve provides a fluid seal between the rotor chamber and the stator core, as Chong et al. teach. The motivation to do so would depend on cost, weight and desired electromagnetic performance (page 8 ll 30- page 9 line 5 of Chong et al.). Regarding claim 17/1, Roesel et al. teaches the invention as discussed above, except wherein: the stator core defines a plurality of stator core slots; the stator sleeve comprises a plurality of slot wedges; and the stator core and the stator sleeve are mechanically engaged such that each slot wedge blocks an opening of a respective stator core slot. Chong et al. teach wherein: the stator core (50) defines a plurality of stator core slots (70); the stator sleeve comprises a plurality of slot wedges (72, abstract); and the stator core (50) and the stator sleeve (40,80) are mechanically engaged such that each slot wedge (72) blocks an opening of a respective stator core slot (70, Fig 3b). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing of the invention to modify Roesel in view of Chong et al. wherein: the stator core defines a plurality of stator core slots; the stator sleeve comprises a plurality of slot wedges; and the stator core and the stator sleeve are mechanically engaged such that each slot wedge blocks an opening of a respective stator core slot, as Chong et al. teach. The motivation to do so would depend on cost, weight and desired electromagnetic performance (page 8 ll 30- page 9 line 5 of Chong et al.). Regarding claims 18/17, Roesel et al. in view of Chong et al. disclose the invention as discussed above, except for explicitly mentioning wherein each slot wedge comprises a magnetic material having a relative permeability of at least 10 and an intrinsic coercivity no greater than 1 kAm.−1. Since, Roesel et al. teaches the use of materials with relatively high permeability and conductivity, in order to achieve low eddy currents (C3 ll 59-68) and Chong et al. discloses an apparatus having a stator sleeve (40,80, abstract) for the purpose of withstanding fluid pressures and based on desired electromagnetic performance (page 8 ll 30- page 9 line 5). However, a skilled artisan would readily recognize the benefits of combining the teachings of Roesel et al. in view of Chong et al. to have make a machine wherein each slot wedge comprises a magnetic material having a relative permeability of at least 10 and an intrinsic coercivity no greater than 1 kAm.−1, since it would depend on cost, weight and desired electromagnetic performance (page 8 ll 30- page 9 line 5 of Chong et al.) and desired levels of a high permeability, low eddy current and high electrical conductivity (abstract of Roesel et al.). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing of the invention to modify Roesel et al. in view of Chong et al. wherein each slot wedge comprises a magnetic material having a relative permeability of at least 10 and an intrinsic coercivity no greater than 1 kAm.−1. The motivation to do so would depend on cost, weight and desired electromagnetic performance (page 8 ll 30- page 9 line 5 of Chong et al.) and desired levels of a high permeability, low eddy current and high electrical conductivity, cost, power (abstract, C2 ll 5-63 of Roesel et al.). Regarding claim 19/1, Roesel et al. teaches wherein the stator core is disposed around the rotor chamber; or the rotor chamber (40) is disposed around the stator core (20). Claim(s) 5, 8-15 are rejected under 35 U.S.C. 103 as being unpatentable over Roesel et al. (US 4600873) in view of Chong et al. (GB 2509738), further in view of Petrov et al. (US 8040007). Regarding claims 5/1, Roesel et al. in view of Chong et al. disclose the invention as discussed above, except wherein the stator sleeve has a composite structure comprising a matrix and a filler distributed in the matrix, wherein the filler comprises the magnetic material. Petrov et al. discloses a device wherein the sleeve has a composite structure comprising a matrix and a filler distributed in the matrix, wherein the filler comprises the magnetic material (C15 ll 12-14). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing of the invention to modify Roesel et al. in view of Chong et al. wherein their stator sleeve has a composite structure comprising a matrix and a filler distributed in the matrix, wherein the filler comprises the magnetic material, as Petrov et al. discloses. The motivation to do so is that it would provide structural support and corrosion protection, sealing from foreign object (C15 ll 15-33 of Petrov et al.) Regarding claims 8/5, Roesel et al. in view of Chong et al., further in view of Petrov et al. disclose the invention as discussed above. Roesel et al. in view of Chong et al. do not teach wherein the composite structure further comprises a fibre reinforcement material disposed within the matrix. Petrov et al. discloses a device wherein the composite structure further comprises a fibre reinforcement material disposed within the matrix (C1 ll 40- C2 l 5, C15 ll 15-67). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing of the invention to modify Roesel et al. in view of Chong et al. further in view of Petrov et al. wherein the composite structure further comprises a fibre reinforcement material disposed within the matrix, as Petrov et al. discloses. The motivation to do so is that it would provide structural support and corrosion protection, sealing from foreign object (C15 ll 15-67 of Petrov et al.) Regarding claims 9/8, Roesel et al. in view of Chong et al., further in view of Petrov et al. disclose the invention as discussed above, except wherein the matrix and the fibre reinforcement material together occupy at least 80% of the composite structure by volume. However, a skilled artisan would readily recognize the benefits of combining the teachings of Roesel et al. in view of Chong et al. to choose except wherein the matrix and the fibre reinforcement material together occupy at least 80% of the composite structure by volume, since it would depend on cost, weight and desired electromagnetic performance (page 8 ll 30- page 9 line 5 of Ching et al.) and desired levels of a high permeability, low eddy current and high electrical conductivity, cost, power (abstract, C2 ll 5-63 of Roesel et al.). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing of the invention to modify Roesel et al. in view of Chong et al. except wherein the matrix and the fibre reinforcement material together occupy at least 80% of the composite structure by volume. The motivation to do so would depend on cost, weight and desired electromagnetic performance (page 8 ll 30- page 9 line 5 of Ching et al.) and desired levels of a high permeability, low eddy current and high electrical conductivity, cost,power (abstract, C2 ll 5-63 of Roesel et al.). Regarding claims 10/8, Roesel et al. in view of Chong et al., further in view of Petrov et al. disclose the invention as discussed above. Roesel et al. do not teach wherein the fibre reinforcement material comprises at least one of glass fibres or carbon fibres. Chong et al. discloses a device wherein the fibre reinforcement material comprises at least one of glass fibres or carbon fibres (Page 9 ll 8-16). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing of the invention to modify Roesel et al. in view of Chong et al. further in view of Chong et al. wherein the fibre reinforcement material comprises at least one of glass fibres or carbon fibres, as Chong et al. discloses. The motivation to do so would be based on weight, cost and desired mechanical rigidity (P2 ll 5-12 of Chong et al.). Regarding claim 11/8, Roesel et al. teaches wherein: the stator sleeve (220) is concentric with a rotational axis of the rotor (230). Roesel et al. in view of Chong et al. do not explicitly teach the stator sleeve wherein fibre reinforcement material comprises fibres which are elongate along the rotational axis. However, Roesel teaches the use of a rotor wherein the fibre reinforcement material comprises a plurality of fibres which are elongate along the circumferential direction use of fibers (C15 ll 15-35). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing of the invention to modify Roesel in view of Chong et al. wherein the fibre reinforcement material comprises a plurality of fibres which are elongate along the circumferential direction use of fibers, as Roesel teaches and apply it for the stator. The motivation to do so would be based on desired levels of a high permeability, low eddy current and high electrical conductivity, cost, power (abstract, C2 ll 5-63 of Roesel et al.). Regarding claim 12/8, Roesel et al. teaches wherein: the stator sleeve (220) is defined by a circumferential direction and the rotor wherein the fibre reinforcement material comprises a plurality of fibres which are elongate along the circumferential direction use of fibers (C15 ll 15-35) Roesel et al. do not teach the stator to have the fibre reinforcement material comprises a plurality of fibres which are elongate along the circumferential direction. However, it would have been obvious to a person having ordinary skill in the art before the effective filing of the invention to modify Roesel in view of Chong et al. wherein the fibre reinforcement material comprises a plurality of fibres which are elongate along the circumferential direction use of fibers, as Roesel teaches and apply it for the stator. The motivation to do so would be based on desired levels of a high permeability, low eddy current and high electrical conductivity, cost, power (abstract, C2 ll 5-63 of Roesel et al.). Regarding claim 13/5, Roesel et al. teaches wherein the matrix comprises a polymer resin (C15 ll 15-22). Regarding claim 14/13, Roesel et al. in view of Chong et al. teaches the invention as discussed above, except wherein the matrix comprises a thermosetting polymer resin. Petrov et al. teach the use of a thermosetting resin (C30 ll 38-44). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing of the invention to modify Roesel in view of Chong et al. wherein the matrix comprises a thermosetting polymer resin, as Petrov et al. teach. The motivation to do so is that it would provide structural support and corrosion protection, sealing from foreign object (C15 ll 15-67 of Petrov et al.) Regarding claim 15/14, Roesel et al. in view of Chong et al. teaches the invention as discussed above, except wherein: the thermosetting polymer resin is at least one of an epoxy-based resin or cyanate-ester based resin; and the thermosetting polymer resin comprises at least one of silicone, polyamide or polyimide. Petrov et al. teach the use of a thermosetting resin (C30 ll 38-44) and polyamide (C42 ll 6-7). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing of the invention to modify Roesel in view of Chong et al., further in view of Petrov et al. wherein: the thermosetting polymer resin is at least one of an epoxy-based resin or cyanate-ester based resin; and the thermosetting polymer resin comprises at least one of silicone, polyamide or polyimide, as Petrov et al. teach and apply it as claimed. The motivation to do so is that it would provide structural support and corrosion protection, sealing from foreign object (C15 ll 15-67 of Petrov et al.) Allowable Subject Matter Claim 20 is allowed. The following is a statement of reasons for the indication of allowable subject matter: In claim 20, prior art of record nor any additionally cited art of record teaches or fairly suggests, alone or in combination, inter alia, “the method comprising: operating the electrical machine in a baseline condition; and operating the electrical machine in a fault condition in which the stator windings are electrically connected to each other to form a short-circuit, wherein the stator sleeve provides additional effective inductance to the stator windings such that a fault current induced within the stator windings is inhibited.”. Claims 6/5 and 7/5 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: In claim 6/5 inter alia, the specific limitations of “…wherein the filler comprises particulates distributed in the matrix, wherein the matrix separates the particulates to electrically insulate the particulates.”, in the combination as claimed are neither anticipated nor made obvious over the prior art made of record. In claim 7/5 inter alia, the specific limitations of “…wherein the filler comprises elongate wires extending through the matrix, wherein the matrix separates the elongate wires to electrically insulate the elongate wires.”, in the combination as claimed are neither anticipated nor made obvious over the prior art made of record. 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 The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Please see PTO-892 for details. Any inquiry concerning this communication or earlier communications from the examiner should be directed to NAISHADH N DESAI whose telephone number is (571)270-3038. The examiner can normally be reached 9-5. 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, Christopher M Koehler can be reached at 571-272-3560. 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. NAISHADH N. DESAI Primary Examiner Art Unit 2834 /NAISHADH N DESAI/ Primary Examiner, Art Unit 2834
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Prosecution Timeline

Dec 07, 2023
Application Filed
Dec 17, 2025
Non-Final Rejection — §103
Mar 25, 2026
Response Filed

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Prosecution Projections

1-2
Expected OA Rounds
82%
Grant Probability
91%
With Interview (+8.8%)
2y 7m
Median Time to Grant
Low
PTA Risk
Based on 1089 resolved cases by this examiner