Prosecution Insights
Last updated: April 19, 2026
Application No. 18/700,701

ELECTRIC ROTARY TRANSFORMER

Non-Final OA §102§103
Filed
Apr 11, 2024
Examiner
QURESHI, MOHAMMED AHMED
Art Unit
2834
Tech Center
2800 — Semiconductors & Electrical Systems
Assignee
Mahle International GmbH
OA Round
1 (Non-Final)
85%
Grant Probability
Favorable
1-2
OA Rounds
2y 5m
To Grant
93%
With Interview

Examiner Intelligence

Grants 85% — above average
85%
Career Allow Rate
132 granted / 156 resolved
+16.6% vs TC avg
Moderate +9% lift
Without
With
+8.8%
Interview Lift
resolved cases with interview
Typical timeline
2y 5m
Avg Prosecution
29 currently pending
Career history
185
Total Applications
across all art units

Statute-Specific Performance

§101
0.9%
-39.1% vs TC avg
§103
49.6%
+9.6% vs TC avg
§102
27.5%
-12.5% vs TC avg
§112
20.7%
-19.3% vs TC avg
Black line = Tech Center average estimate • Based on career data from 156 resolved cases

Office Action

§102 §103
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 § 102 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. (a)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention. Claim(s) 1-4, 9, 11, and 15-17 is/are rejected under 35 U.S.C 102(a)(1) and/or 102(a)(2) as being unpatentable over ZADEH(US8228010B2). Regarding claim 1, Zadeh teaches an electric rotary transformer (Para[0002]) for inductive energy transmission (Para[0020]), comprising: a rotary transformer stator (Para[0020]), including a transformer primary coil (32), a rotary transformer rotor (Para[0020]), rotatable during operation relative to the rotary transformer stator about an axially running rotation axis (11), the rotary transformer rotor includes a transformer secondary coil (22), wherein the transformer secondary coil (22) and the transformer primary coil (32) interact inductively during operation for generating a transformer voltage in the transformer secondary coil (Para[0020-0044]), wherein at least one of the transformer secondary coil (22) and the transformer primary coil (32) has at least one electric conductor (Para[0053], hollow conductor) through which a flow path of a fluid is guided (Para[0053]), and wherein during operation a fluid flows along the flow path and cools the rotary transformer(Para[0053]). Regarding claim 2/1, Zadeh teaches the rotary transformer according to claim 1. Zadeh further teaches wherein the transformer primary coil(32) is a flat coil(Para[0053]) and has atleast one electric conductor(Para[0053]). Regarding claim 3/1, Zadeh teaches the rotary transformer according to claim 1. Zadeh further teaches a magnet core(31,21) in which the transformer primary coil(32) and the transformer secondary coil(22) are arranged, wherein the at least one electric conductor is arranged in the magnet core(31,21)(Para[0043-0053]). Regarding claim 4/1, Zadeh teaches the rotary transformer according to claim 1. Zadeh further teaches wherein the at least one of electric conductor has a central cavity(Para[0053], hollow conductor inherently has central cavity) through which the flow path is guided(Para[0053]). Regarding claim 9/1, Zadeh teaches the rotary transformer according to claim 1. Zadeh further teaches wherein the atleast one electric conductor(32) is configured as a hollow conductor(Para[0053]). Regarding claim 11, Zadeh teaches the rotary transformer according to claim 1. Zadeh teaches a separately excited electric synchronous machine(Para[0003] and Para[0039], describes synchronous generator with field winding on rotor and a secondary winding that feeds a rectifier which feeds the field winding = being separately excited via a transformer fed DC), comprising: a machine rotor(1) including a rotor shaft(axis 11 shaft) and a machine rotor coil(Para[0044]) provided in a rotationally fixed manner on the rotor shaft(shaft of rotor 1 on axis 11), the machine rotor coil generates a rotor field during operation(Para[0003], describes field winding producing magnetic field), a machine stator(5) including a machine stator coil(Para[0003], induced AC voltage in stator windings) fixed with respect to the machine stator, the machine stator coil generates in operation a magnetic stator field which that interacts with the rotor field such that the machine rotor(1) during operation rotates about an axial rotation axis(11)(Para[0003], rotor field incudes AC voltage in stator windings), a rotary transformer, the rotary transformer including: a rotary transformer stator including a transformer primary coil(32)(Para[00200 and Para[0045], establishes a stator component with a primary winding), a rotary transformer rotor(secondary 2 rotor side), rotatable during operation relative to the rotary transformer stator about an axially running rotation axis(11), the rotary transformer rotor(secondary 2) include a transformer secondary coil(22), wherein the transformer secondary coil(22) and the transformer primary coil(32) interact inductively during operation for generating a transformer voltage in the transformer secondary coil(22), wherein at least one of the transformer secondary coil and the transformer primary coil has at least one electric conductor(Para[0053], discloses conductor), through which a flow path of a fluid is guided(Para[0053], discloses cooling liquid pumped through conductor), and wherein during operation a fluid flows along the flow path and cools the rotary transformer(Inherent with cooling liquid flowing through it), wherein the rotary transformer stator is fixed with respect to the machine stator(Para[0042], primary 3 is transformer stator side which is fixed), wherein the rotary transformer rotor(secondary 2 rotor side) is arranged on the machine rotor(1) in a rotationally fixed manner, and wherein the machine rotor coil(22) is connected to the transformer secondary coil such that the machine rotor coil is supplied during operation with a direct voltage for generating the rotor field(Para[00039-0050], secondary winding to rectifier to rotor field winding). Regarding claim 15/11, Zadeh teaches the separately excited electric synchronous machine according to claim 11. Zadeh further teaches wherein the transformer primary coil(32) is a flat coil(Para[0053]) and has atleast one electric conductor(Para[0053]). Regarding claim 16/11, Zadeh teaches the separately excited electric synchronous machine according to claim 1. Zadeh further teaches a magnet core(31,21) in which the transformer primary coil(32) and the transformer secondary coil(22) are arranged, wherein the at least one electric conductor is arranged in the magnet core(31,21)(Para[0043-0053]). Regarding claim 17/11, Zadeh teaches the separately excited electric synchronous machine according to claim 1. Zadeh further teaches wherein the at least one of electric conductor has a central cavity(Para[0053], hollow conductor inherently has central cavity) through which the flow path is guided(Para[0053]). 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. Claim(s) 5-8, 10, and 18-20 is/are rejected under 35 U.S.C 103 as being unpatentable over ZADEH(US8228010B2) in view of HALDEMAN(US5461215A). Regarding claim 5/4, Zadeh teaches the rotary transformer according to claim 4. Zadeh is silent wherein a channel body, receiving in the cavity, delimits the flow path. However, Haldeman teaches a channel body(1), delimits the flow path(Figs. 5-6, Channel body 1 houses conductor 10, which forms boundary of coolant flow channel, meaning it delimits the flow). Haldeman is considered to be analogous to the claimed invention of Zadeh because they are in the same field of electric machines. Therefore, it would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to have further modified Zadeh wherein a channel body, receiving in the cavity, delimits the flow path, as taught by Haldeman. One of ordinary skill in the art would be motivated to do this in order to have controlled coolant routing, improved thermal management, and overall increased efficiency. Regarding claim 6/5, Zadeh in view of Haldeman teaches the rotary transformer according to claim 5. Haldeman further teaches wherein the channel body(1) is a flexible tube(Haldeman teaches the tube made of hollow plastic or elastomeric insulation and being flexible enough to permit re-orienting turns). Regarding claim 7/1, Zadeh teaches the rotary transformer according to claim 1. Zadeh is silent wherein the at least one electric conductor is configured as a braid. However, Haldeman teaches the at least one electric conductor(10) configured as a braid(Teaches mixed or braided construction). Haldeman is considered to be analogous to the claimed invention of Zadeh because they are in the same field of electric machines. Therefore, it would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to have further modified Zadeh wherein the at least one electric conductor is configured as a braid, as taught by Haldeman. One of ordinary skill in the art would be motivated to do this in order to reduce losses and increase efficiency. Regarding claim 8/7, Zadeh in view of Haldeman teaches the rotary transformer according to claim 7. Haldeman further teaches wherein the braid has individual wires, wherein at least a portion of the individual wires is received in an electrically insulating casing(Haldeman discloses the litz cable conductor 10 is comprised of a bundle of mutually electrically insulated, intermixed wire filaments). Regarding claim 10/1, Zadeh teaches the rotary transformer according to claim 1. Zadeh further teaches comprising an inlet(inherent in a pumped system) for letting in the fluid into the at least one electric conductor(32) and an outlet(inherent in a pumped system) for letting the fluid out. Zadeh is silent wherein the electric conductor is configured as a braid. However, Haldeman teaches the at least one electric conductor(10) configured as a braid(Teaches mixed or braided construction). Haldeman is considered to be analogous to the claimed invention of Zadeh because they are in the same field of electric machines. Therefore, it would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to have further modified Zadeh wherein the at least one electric conductor is configured as a braid, as taught by Haldeman. One of ordinary skill in the art would be motivated to do this in order to reduce losses and increase efficiency. Regarding claim 18/11, Zadeh teaches the separately excited electric synchronous machine according to claim 11. Zadeh is silent wherein the at least one electric conductor is configured as a braid. However, Haldeman teaches the at least one electric conductor(10) configured as a braid(Teaches mixed or braided construction). Haldeman is considered to be analogous to the claimed invention of Zadeh because they are in the same field of electric machines. Therefore, it would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to have further modified Zadeh wherein the at least one electric conductor is configured as a braid, as taught by Haldeman. One of ordinary skill in the art would be motivated to do this in order to reduce losses and increase efficiency. Regarding claim 19/18, Zadeh in view of Haldeman teaches the separately excited electric synchronous machine according to claim 18. Haldeman further teaches wherein the braid has individual wires, wherein at least a portion of the individual wires is received in an electrically insulating layer(Haldeman discloses the litz cable conductor 10 is comprised of a bundle of mutually electrically insulated, intermixed wire filaments). Regarding claim 20/18, Zadeh teaches the separately excited electric synchronous machine according to claim 19. Zadeh further teaches comprising an inlet(inherent in a pumped system) for letting in the fluid into the at least one electric conductor(32) and an outlet(inherent in a pumped system) for letting the fluid out. Haldeman teaches the at least one electric conductor(10) configured as a braid(Teaches mixed or braided construction). Claim(s) 12-14 is/are rejected under 35 U.S.C 103 as being unpatentable over ZADEH(US8228010B2) in view of ZHOU(US7841431B2). Regarding claim 12, Zadeh teaches a separately excited electric synchronous machine the separately excited electric synchronous machine(Para[0003] and Para[0039], describes synchronous generator with field winding on rotor and a secondary winding that feeds a rectifier which feeds the field winding = being separately excited via a transformer fed DC) including: a machine rotor(1) including a rotor shaft(axis 11 shaft) and a machine rotor coil(Para[0044]) provided in a rotationally fixed manner on the rotor shaft(shaft of rotor 1 on axis 11), the machine rotor coil generates a rotor field during operation(Para[0003], describes field winding producing magnetic field), a machine stator(5) including a machine stator coil(Para[0003], induced AC voltage in stator windings) fixed with respect to the machine stator, the machine stator coil generates in operation a magnetic stator field which that interacts with the rotor field such that the machine rotor(1) during operation rotates about an axial rotation axis(11)(Para[0003], rotor field incudes AC voltage in stator windings), a rotary transformer, the rotary transformer including: a rotary transformer stator including a transformer primary coil(32)(Para[00200 and Para[0045], establishes a stator component with a primary winding), a rotary transformer rotor(secondary 2 rotor side), rotatable during operation relative to the rotary transformer stator about an axially running rotation axis(11), the rotary transformer rotor(secondary 2) include a transformer secondary coil(22), wherein the transformer secondary coil(22) and the transformer primary coil(32) interact inductively during operation for generating a transformer voltage in the transformer secondary coil(22), wherein at least one of the transformer secondary coil and the transformer primary coil has at least one electric conductor(Para[0053], discloses conductor), through which a flow path of a fluid is guided(Para[0053], discloses cooling liquid pumped through conductor), and wherein during operation a fluid flows along the flow path and cools the rotary transformer(Inherent with cooling liquid flowing through it), wherein the rotary transformer stator is fixed with respect to the machine stator(Para[0042], primary 3 is transformer stator side which is fixed), wherein the rotary transformer rotor(secondary 2 rotor side) is arranged on the machine rotor(1) in a rotationally fixed manner, and wherein the machine rotor coil(22) is connected to the transformer secondary coil such that the machine rotor coil is supplied during operation with a direct voltage for generating the rotor field(Para[00039-0050], secondary winding to rectifier to rotor field winding). Zadeh does not explicitly teach a motor vehicle and a cooling circuit, in which the synchronous machine is integrated, so that the fluid circulates along the flow path. However, Zhou teaches a motor vehicle(200) and a cooling circuit(203), in which the synchronous machine is integrated, so that the fluid circulates along the flow path. Zhou is considered to be analogous to the claimed invention of Zadeh because they are in the same field of electric machines. Therefore, it would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to have further modified Zadeh a motor vehicle and a cooling circuit, in which the synchronous machine is integrated, so that the fluid circulates along the flow path, as taught by Zhou. One of ordinary skill in the art would be motivated to do this in order to have controlled coolant routing, improved thermal management, and overall increased efficiency. Regarding claim 13/12, Zadeh in view of Zhou teaches the motor vehicle according to claim 12. Zhou further teaches wherein during operation, the synchronous machine, as traction motor(111), drives the motor vehicle(Para[0011]). Regarding claim 14/11, Zadeh teaches the motor vehicle according to claim 11. Zadeh teaches the separately excited electric synchronous machine(Para[0003] and Para[0039], describes synchronous generator with field winding on rotor and a secondary winding that feeds a rectifier which feeds the field winding = being separately excited via a transformer fed DC). Zadeh does not explicitly teach a traction motor comprising the separately excited synchronous machine. However, Zhou teaches a traction motor (111)(Para[0011]). Zhou is considered to be analogous to the claimed invention of Zadeh because they are in the same field of electric machines. Therefore, it would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to have further modified Zadeh wherein the synchronous machine is a traction motor, as taught by Zhou. It would have been obvious to use the synchronous machine of Zadeh as a traction motor as taught by Zhou because synchronous machines are well-known motor architecture, and applying a known motor architecture to a known propulsion application constitutes a predictable use of prior art elements according to their established functions. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to MOHAMMED QURESHI whose telephone number is (571)-272-8310. The examiner can normally be reached on 8:30 AM - 6:00 PM. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Tulsidas Patel can be reached on 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 an application may be obtained from the Patent Application Information Retrieval (PAIR) system. Status information for published applications may be obtained from either Private PAIR or Public PAIR. Status information for unpublished applications is available through Private PAIR only. For more information about the PAIR system, see http://pairdirect. uspto.gov. Should you have questions on access to the Private PAIR system, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). /MOHAMMED AHMED QURESHI/ Examiner, Art Unit 2834 /TULSIDAS C PATEL/ Supervisory Patent Examiner, Art Unit 2834
Read full office action

Prosecution Timeline

Apr 11, 2024
Application Filed
Mar 02, 2026
Non-Final Rejection — §102, §103 (current)

Precedent Cases

Applications granted by this same examiner with similar technology

Patent 12603559
VARIABLE CROSS-SECTION CONDUCTORS TO REDUCE ALTERNATING CURRENT LOSSES FOR AXIAL FLUX, RADIAL FLUX AND MOTORS WITH SKEW
2y 5m to grant Granted Apr 14, 2026
Patent 12597837
System and method for starting high inertia machines
2y 5m to grant Granted Apr 07, 2026
Patent 12597820
Electrical Assembly Structure and Motors with Electrical Assembly Structure
2y 5m to grant Granted Apr 07, 2026
Patent 12597827
CONTROL DEVICE, MOTOR DEVICE, AND OIL PUMP DEVICE
2y 5m to grant Granted Apr 07, 2026
Patent 12595841
Breather With Pressure-Equalization Function
2y 5m to grant Granted Apr 07, 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
85%
Grant Probability
93%
With Interview (+8.8%)
2y 5m
Median Time to Grant
Low
PTA Risk
Based on 156 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