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 .
Information Disclosure Statement
The information disclosure statement (IDS) submitted on 05/08/2024 is/are in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statement are being considered by the examiner.
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.
Claims 2, 5, 9, and 10 are 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.
Claim 2 recites the limitation "a half bridge of controllable semiconductor switches; and
two capacitors in series; wherein the half-bridges and the capacitors are arranged between the DC terminals and in a parallel connection; and the midpoint of the half-bridges and the midpoint of the capacitor series each form a field conductor terminal." In lines 4-8. There is insufficient antecedent basis for this limitation in the claim. Firstly, claim introduces a singular half bridge in line 4, then discloses a plurality of half bridges in lines 7 and 10. Secondly, there were no previous introductions of midpoints of half-bridges and midpoints of a capacitor series as recited in lines 10-11. Furthermore, it is unclear if the “capacitor series” in line 11 is meant to refer to the “capacitors in series” as previously introduced in line 6. Lastly, the claim had previously introduced a first and second field conductor terminal in claim 1, and it is unclear if the field conductor terminal recited in line 11 is the same field conductor terminal of claim 1 or a new field conductor terminal. Appropriate correction is required.
Claim 5 recites the limitation "there is an equal number of field conductors, field conductor terminals, and second field conductor terminals" in lines 2-4. There is insufficient antecedent basis for this limitation in the claim. The initial recitation of “field conductor terminals” grammatically encompasses a plural set of terminals. Introducing a second plural set of “second field conductor terminals” contributes to redundancy based on the initial recitation of plural “field conductor terminals”. For clarity, Applicant is advised to improve claim language to distinguish two independent field conductor terminals.
Claim 9 recites the limitation "each field conductor is connected between a field conductor terminal of an inverter and a second field conductor terminal of a second inverter; and
the inverter and second inverter occupy the same position in their respective series" in lines 3-8. There is insufficient antecedent basis for this limitation in the claim. Applicant initially introduces a plurality of inverters in claim 8 and 1, it is unclear if the singular inverter and second singular inverter of this claim are meant to refer to one of the plurality of inverters introduced in claims 8 and 1, or if the singular inverter and the second singular inverter are independent inverters of the inverters introduced in claims 8 and 1. Similarly, a plurality of field conductor terminals had been introduced in claim 1, and it is unclear if the field conductor terminal of this claim is meant to refer to one of the plurality of field conductor terminals of claim 1, or if the field conductor terminal of this claim is a separate and independent field conductor terminal. Appropriate correction is required.
Claim 10 recites the limitation " wherein the DC terminals of the AC/DC converter arrangement are connected to DC terminals of said series of inverters and said series of second inverters" in lines 3-5. There is insufficient antecedent basis for this limitation in the claim. The initial recitation of a plural series of inverters grammatically encompasses any second series of inverters. For clarity, Applicant is advised to improve claim language to distinguish between the series of inverters.
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) 1,3, 5, 6, and 8-10 are rejected under 35 U.S.C. 103 as being unpatentable over Carsten (DE102005032965A1).
Claim 1
Carsten teaches: An electric drive comprising:
a stator (2) having a plurality of field conductors (6) for generating a magnetic field;
one or more inverters (components on one selective end of either circuit board 24 or 28, para. 0009) arranged at a first axial end of the stator (2) and each comprising two DC terminals (18, 20) and two field conductor terminals (12), wherein each field conductor terminal (12) is connected to a first terminal of one or more of the field conductors (6)-; and
one or more second inverters (components on selective second end of either circuit board 24 or 28, para. 0009) arranged at a second axial end of the stator (2) and each comprising two DC terminals (18, 20) and two second field conductor terminals (12), wherein each second field conductor terminal (12) is connected to a second terminal of one or more of the field conductors (6).
PNG
media_image1.png
378
342
media_image1.png
Greyscale
PNG
media_image2.png
440
538
media_image2.png
Greyscale
PNG
media_image3.png
356
540
media_image3.png
Greyscale
Carsten does not explicitly disclose: The electric drive as comprising: a rotor, and
the plurality of field conductors of the stator as generating a magnetic field to convey a torque to the rotor;
Although Carsten does not explicitly recite the limitation above, Carsten expressly references rotors in the background (see para. 0030), noting that rod-shaped conductors are commonly used in rotors of asynchronous motors. Additionally, Carsten’s repeated discussion of torque generation (see para. 0011 and 0043) inherently implies the presence of a rotor, as torque in an electric motor is necessarily produced by electromagnetic interaction between a stator-generated magnetic field and a rotor.
A person having ordinary skill in the art (PHOSITA would have understood that the disclosed power converter motor of Carsten necessarily includes a rotor, wherein the stator’s field conductors generate a magnetic field to convey torque to the rotor, as claimed. A PHOSITA would have been motivated to include a rotor as claimed in order to enable the conversion of electrical energy into mechanical torque, which is the expressly stated purpose of the motor (as evidenced by Carsten’s repeated references to torque development and torque quality).
Claim 3/1
Carsten teaches: The electric drive of claim 1, wherein:
the one or more first inverters (components on one selective end of either circuit board 24 or 28, para. 0009) and the one or more second inverters (components on selective second end of either circuit board 24 or 28, para. 0009) each comprise two half-bridges (Plural parallel connected switches 14 connected to positive DC rail, switches 16 connected to negative DC rail, and midpoint nodes 12 form half-bridges) of controllable semiconductor switches (14, 16);
all of the half-bridges are arranged between the DC terminals (18, 20) and in a parallel connection (as illustrated in Fig. 2);
the midpoint (12) of the half-bridges (Plural arrangements of 14, 16, and 12) each form a field conductor terminal (12).
Claim 5/1
Carsten teaches: The electric drive of claim 1, wherein there is an equal number of field conductors (6), field conductor terminals (12), and second field conductor terminals (12).
Claim 6/1
Carsten teaches: The electric drive of claim 1, wherein the field conductors (6) comprise bars arranged in parallel (see. Fig. 8).
PNG
media_image4.png
360
550
media_image4.png
Greyscale
Claim 8/1
Carsten teaches: The electric drive of claim 1, comprising at least two of said inverters (components on one selective end of either circuit board 24 or 28, para. 0009) and an equal number of said second inverters (components on selective second end of either circuit board 24 or 28, para. 0009);
wherein said inverters (components on one selective end of either circuit board 24 or 28, para. 0009) form a first series with respective DC terminals (18, 20); and
said second inverters (components on selective second end of either circuit board 24 or 28, para. 0009) form a second series with respective DC terminals (18, 20).
Claim 9/8/1
Carsten teaches: The electric drive of claim 8, wherein:
each field conductor (6) is connected between a field conductor terminal (12) of an inverter (components on one selective end of either circuit board 24 or 28, para. 0009) and a second field conductor terminal (12) of a second inverter (components on selective second end of either circuit board 24 or 28, para. 0009); and
the inverter (components on one selective end of either circuit board 24 or 28, para. 0009) and second inverter (components on selective second end of either circuit board 24 or 28, para. 0009) occupy the same (radial) position in their respective series.
Claim 10/9/8/1
Carsten teaches: The electric drive of claim 9, comprising an AC/DC converter arrangement;
wherein the DC terminals (18, 20) of the AC/DC converter arrangement are connected to DC terminals (18, 20) of said series of inverters (components on one selective end of either circuit board 24 or 28, para. 0009) and said series of second inverters (components on selective second end of either circuit board 24 or 28, para. 0009).
Claim(s) 2 is rejected under 35 U.S.C. 103 as being unpatentable over Carsten in view of Joachim (AU 2015240092 A1).
Claim 2/1
Carsten teaches: The electric drive of claim 1, wherein each of the first and second inverters (components on circuit boards 24 and 28, para. 0009) comprises:
a half bridge (Switch 14 connected to positive DC rail, Switch 16 connected to negative DC rail, and midpoint node 12 form half-bridge) of controllable semiconductor switches (14, 16);
wherein the half-bridges are arranged between the DC terminals (18, 20) and in a parallel connection; and
the midpoint of the half-bridges (12) and the midpoint of the capacitor series each form a field conductor terminal.
Carsten is silent to providing the electric drive of claim 1 with two capacitors in series; wherein the half-bridges and the capacitors are arranged between the DC terminals and in a parallel connection; and the midpoint of the half-bridges and the midpoint of the capacitor series each form a field conductor terminal.
Although Carsten doesn’t explicitly disclose this limitation, it is well known in the art of power electronics that half-bridge inverter topologies commonly employ two series connected capacitors across the DC bus to a) provide a midpoint voltage, enable bidirectional voltage application relative to a reference node, and stabilize the DC-link voltage while reducing voltage ripple. For example, Joachim teaches an electric device comprised of an inverter (8) connected in parallel to series-connected capacitors 6 and 13.
PNG
media_image5.png
780
944
media_image5.png
Greyscale
A person having ordinary skill in the art (PHOSITA) would have recognized that incorporating such a split-capacitor DC-link into the inverter of Carsten would provide a convenient and stable midpoint node corresponding to the switching node of the half-bridge. This midpoint can then serve as the field conductor terminal, as claimed. A PHOSITA would have been motivated to implement the claimed capacitor arrangement in Carsten in order to ensure balanced voltage division across the DC bus and provide a stable midpoint reference, improving inverter performance.
Claim(s) 4 and 7 are rejected under 35 U.S.C. 103 as being unpatentable over Carsten in view of Patzak (US 20160087497 A1).
Claim 4/3/1
Carsten teaches: The electric drive of claim 3, wherein, for each field conductor, but does not explicitly disclose: a first of the connected half-bridges of controllable semiconductor switches is operated with pulse width modulation switching and a second of connected the half-bridges of controllable semiconductor switches is switched at a fundamental frequency of the AC voltage supplied by the inverters .
Although Carsten does not explicitly disclose the limitation above, Carsten does however teach that, due to very low inductance of Carsten’s conductors, the semiconductor switches must be operated at very high switching frequencies in order to prevent excessive current amplitudes and associated device damage (see para. 0036). Carsten also recognizes that high temperatures occur in the conductors, indicating thermal constraints in operation.
Patzak supplementarily teaches that half-bridges in such electric drive systems are controlled using pulse-width modulation signals (see. Para. 0103), demonstrating that PWM operation of half-bridges is well known.
It is further well known in the art that operating semiconductor switches at high switching frequencies (e.g. PWM) increases switching losses and thermal stress, whereas operating switches as a fundamental frequency reduces switching losses and improves efficiency.
In view of Carsten’s recognition of the need for high switching frequency and the associated thermal concerns, it would have been obvious to a person having ordinary skill in the art before the time of the claimed invention, to operate a first of the connected half-bridges using PWM switching, while operating a second of the connected half-bridges at a lower, fundamental frequency, in order to reduce switching losses and thermal loading while still maintaining adequate current control. Such a modification represents a predictable optimization of switching strategies in response to known trade-offs between switching frequency, device protection, and thermal performance.
Claim 7/1
Carsten teaches: The electric drive of claim 1, comprising 18 field conductors (6), but is silent to: comprising at least at least 24 field conductors.
Although Carsten is silent to the limitation above, it is a well known virtue within the art to increase the number of field conductors comprised similar electric drives as that taught by Carsten. For example, Patzak teaches an electric drive comprising a plurality of 36 field conductors (13) distributed circumferentially about a stator (1).
PNG
media_image6.png
672
610
media_image6.png
Greyscale
In view of the teachings of Patzak, it would have been obvious to a person having ordinary skill in the art before the time of the claimed invention to modify Carsten to include a greater number of field conductors than 18, such as 24 or more, as a matter of routine design choice to achieve desired performance characteristics. Selecting a specific number of conductors within the known range (e.g., between 18 and 36) would have been the result of routine optimization based on application requirements.
Claim(s)11 is rejected under 35 U.S.C. 103 as being unpatentable over Carsten in view of Moros (WO2020156957A1).
Claim 11/1
Carsten teaches: The electric drive of claim 1, but does not explicitly disclose: wherein the AC/DC converter arrangement comprises two AC/DC converters arranged in parallel and connected to a multi-winding transformer with their AC terminals.
Moros supplementarily discloses a power supply system for an electric drive including a transformer connected to an AC power source and one or more converters configured to convert between AC and DC power (see, e.g. para. 0100-0102). Moros further teaches that a plurality of transformers and associated conversion components may be connected in parallel to increase the amount of power transferred.
It is well known in the art of the claimed invention that converters, including AC/DC converters, may be arranged in parallel to increase power capacity, improve efficiency, and distribute thermal loading. It is also well known that a transformer may include multiple windings to accommodate multiple converter connections within a single integrated component, thereby reducing system complexity and improving efficiency.
In view of Moros’s teachings of parallel power conversion architectures for increasing power transfer, it would have been obvious to one of ordinary skill in the art before the time of the claimed invention to modify the AC/DC converter arrangement of Carsten to include two AC/DC converters arranged in parallel and connected to a multi-winding transformer at their AC terminals, as a predictable variation to achieve increased power handling capability and improved system efficiency.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to AHMED F SECK whose telephone number is (571)272-4638. The examiner can normally be reached Monday - Friday 7:30 am - 4:30 pm.
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 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.
/AHMED F SECK/ Examiner, Art Unit 2834
/CHRISTOPHER M KOEHLER/ Supervisory Patent Examiner, Art Unit 2834
Prosecution Insights