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 .
Status of Claims
Receipt is acknowledged of an claims, filed on 06/05/2025, which has been placed of record and entered in the file.
Status of the claims:
Claims 1-20 are pending for examination.
Information Disclosure Statement
Receipt is acknowledged of an Information Disclosure Statement, filed 07/10/2025, which has been placed of record in the file. An initialed, signed and dated copy of the PTO-1449 or PTO-SB-08 form is attached to this Office action.
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 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.
Claim(s) 1-6 and 19 is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Yajurvedi et al. (US 20200389109 A1).
Regarding claim 1, Yajurvedi discloses a power tool ([0003]), comprising:
a sensorless, brushless, electric motor (16; [0083]) comprising a rotor (40, 42) and multi-phase stator windings (52; [0083]-[0085]);
a power supply module (206) configured to supply power to the electric motor (16) and connected to a power supply ([0087]-[0088], and Fig. 4);
a driver circuit (226) electrically connected to the electric motor (16) and the power supply module (206) and configured to apply a voltage of the power supply module to the electric motor ([0088] and [0098]-[0111]);
a control module (230) electrically connected to the driver circuit and configured to output a control signal to the driver circuit to control the driver circuit ([0089], [0099]; Fig. 4); and
a detection module electrically connected to the multi-phase stator windings and configured to detect an electrical parameter of each of the multi-phase stator windings during operation of the electric motor (see [0102], [0107]-[0115], and [0203]; Figs. 4-5, 30; voltage signals PU, PV, PW taken directly from motor phase terminals; back-EMF voltage is the electrical parameter detected on the windings);
wherein the electric motor has an unenergized, coasting state in an open-loop control mode, the detection module detects an electrical parameter of each of the multi-phase stator windings of the electric motor in the coasting state ([0152] “Open-loop frequency command start-up”), [0203] “in coasting motor, since all the switches pf the power switch circuit 226 are off, the phase signals…only carry the motor back-EMF”, [0207] and Figs. 28-29 (spinning restart process 410), and Fig. 30 shows the time graph 500 explicitly showing “motor coasting period 512” during which all switches are OFF…see also [0186]-[0188]), and the control module (230) is configured to control the electric motor to switch from the open-loop control mode to a closed-loop control mode when the electrical parameter detected by the detection module reaches a preset electrical parameter value ([0131]-[0134], [0172]-[0176], [0190]-[0196] and [0203]; and Figs 29-30; after back-EMF detection during coasting period 512, controller 230 switched to closed loop sensorless operation using sliding-mode observer (SMO) 350 once the back-EMF reaches a level sufficient for reliable rotor position estimation. The preset value required for SMO to function accurately; explicit transition from coasting/open-loop state to closed-loop SMO commutation).
Regarding claim 2, wherein, in the open-loop control mode, the electric motor can be in a driving state and the coasting state, when the electric motor is in the driving state, the control module controls the power supply to supply power to the multi-phase stator windings, and when the electric motor is in the coasting state, the control module controls the power supply to stop supplying power to the multi-phase stator windings ([0152]-[0166] “Open loop frequency command start-up….controller issues an open-loop frequency command for motor startup… while the parking force is still being applied to the motor, controller 230 begins to generate and apply HFI voltage signals to the motor”. The power is supplied via the power switch circuit. Similarly, in the coasting sate: [0203] “in a coasting motor, since all switches of the power circuit 226 are off, the phase signals only carry the motor back-EMF” and Fig. 30 (motor coating period 512 with all switched deactivated). The coasting occurs as part of the overall open-loop/sensorless sequence (spinning restart process 410, Figs. 28-30)…See also [0097]-[0099] and [0184]-[0188]).
Regarding claim 3, wherein the electrical parameter is one of a voltage, a current, a slope of a voltage, and a derivative of a voltage ([0102]-[0115] and [0203] explains that phase currents are measured using shunt resistors, and phase voltage signals are monitored. Additionally, determining back-EMF detection inherently involves detecting the change or slope of the voltage waveform associated with rotor motion…Fig. 30).
Regarding claim 4, wherein the control module (230) is configured to output a control signal with a preset duty cycle at a preset frequency to control the multi-phase stator windings to conduct and communicate in a preset commutation sequence ([0099] explains that the controller 230 outputs drive signals to the power switch circuit and [0128] describes space vector pulse width modulation (SVPWM) used to generate PWM duty cycles for the inverter switches which inherently involves generating PWM signals with specific duty cycles, at a defined switching frequency to control commutation of the motor phases…see also [0152]).
Regarding claim 5, wherein the power supply is a battery pack ([0086]).
Regarding claim 6, wherein the power supply is an alternating current, and the driver circuit further comprises a rectifier module configured to convert the alternating current into a direct current ([0087]-[0088] describes converting the AC power into DC power via rectifier circuit 220; Fig. 4).
Regarding claim 19, Yajurvedi discloses a control method of a power tool ([0003]), comprising:
a sensorless, brushless, electric motor (16; [0083]) comprising a rotor (40, 42) and multi-phase stator windings (52; [0083]-[0085]);
a power supply module (206) configured to supply power to the electric motor (16) and connected to a power supply ([0087]-[0088], and Fig. 4);
a driver circuit (226) electrically connected to the electric motor (16) and the power supply module (206) and configured to apply a voltage of the power supply module to the electric motor ([0088] and [0098]-[0111]);
a control module (230) electrically connected to the driver circuit and configured to output a control signal to the driver circuit to control the driver circuit ([0089], [0099]; Fig. 4);
a detection module electrically connected to the multi-phase stator windings and configured to detect an electrical parameter of each of the multi-phase stator windings during operation of the electric motor (see [0102], [0107]-[0115], and [0203]; Figs. 4-5, 30; voltage signals PU, PV, PW taken directly from motor phase terminals; back-EMF voltage is the electrical parameter detected on the windings); wherein the method comprises: controlling the electric motor to enter an open-loop control mode when a start signal is detected; detecting, in the open-loop control mode, the electrical parameter of each of the multi- phase stator windings of the electric motor in an unenergized coasting state ([0152] “Open-loop frequency command start-up”), [0203] “in coasting motor, since all the switches pf the power switch circuit 226 are off, the phase signals…only carry the motor back-EMF”, [0207] and Figs. 28-29 (spinning restart process 410), and Fig. 30 shows the time graph 500 explicitly showing “motor coasting period 512” during which all switches are OFF…see also [0186]-[0188]); and controlling the electric motor to switch from the open-loop control mode to a closed-loop control mode when the electrical parameter reaches a threshold of a preset electrical parameter ([0131]-[0134], [0172]-[0176], [0190]-[0196] and [0203]; and Figs 29-30; after back-EMF detection during coasting period 512, controller 230 switched to closed loop sensorless operation using sliding-mode observer (SMO) 350 once the back-EMF reaches a level sufficient for reliable rotor position estimation. The preset value required for SMO to function accurately; explicit transition from coasting/open-loop state to closed-loop SMO commutation).
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 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.
The factual inquiries set forth in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), that are applied 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.
Claims 9-10 is/are rejected under 35 U.S.C. 103 as being unpatentable over Yajurvedi et al. (US 20200389109 A1) in view of Boyd et al. (US 6034493 A).
Regarding claim 9, Yajurvedi discloses wherein the control module (230) to control PWM duty cycles for motor speed regulation (“Space vector pulse width modulated (SVPWM) control to the drive to achieve desired currents [0099]-[0100], [0128]; Figs. 4-5) but is silent regarding configured to: increase a duty cycle of a pulse-width modulation signal at a first preset rate after controlling the duty cycle of the pulse-width modulation signal to decrease to a first duty cycle; and control the duty cycle of the pulse-width modulation signal to decrease to a second duty cycle when a present load parameter meets a second condition.
Boyd in a related invention teaches in a BLDC motor control module (via microprocessor 22 and circuit 22) configured to decrease PWM duty to a first duty cycle (decrement by 1% or 5%....Col 6 lines 21-66); if the calculated rotor speed is less than n the duty cycle value held in location 3 will be incremented (say by 1%) and if the rotor speed is greater than n the duty cycle value at 33 will be decremented by say 1%. (See also Col 8 lines 30-66; the software uses two preset rates: if the speed of the motor is within 10%of the desired speed, the PWM rate is altered by 1%. and 2. If the speed of the motor is not within 10%, the PWM rate is altered by 5%).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified PWM duty control of Yajurvedi by incorporating iterative decrease-then-increase sequence at preset rates as taught by Boyd in order to achieve precise speed regulation under varying loads, preventing over speed or stall, and for efficiency/relaibility. Additionally, the modification is a predictable use of known PWM adaptation techniques for stable operation.
Regarding claim 10, Yajurvedi discloses wherein the control module (230) is further configured to control the electric motor (26) to operate in a first mode ([0196] “…if the calculated rotor speed ω is greater than the HFI speed threshold, controller 230 executes SMO in steps 446-456 for spinning restart of the motor” and [0024] “the controller commutates the motor according to the first estimation of the angular position, gradually modifies the commutation of the motor until the first estimation of the angular position substantially matches the second estimation of the angular position, and commutates the motor according to the second estimation of the angular position thereafter) when the present load parameter does not meet the second condition (brake condition or stall recovery).
Allowable Subject Matter
Claims 7-8, 11-13, and 20 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.
Claims 15-18 are allowed.
With regards to claim 15, Based upon a thorough examination of the specific device of the Applicant' s claimed invention, the Examiner has determined that no prior art exists that anticipates the limitations listed below in the application. Furthermore, the Examiner does not believe it would be reasonable to formulate a 103 combination solely for the purpose of the rejection. The specific limitation that distinguish this application over the prior art include among other structural limitations “a control module electrically connected to the driver circuit and configured to output a control signal to the driver circuit to control the driver circuit and control the electric motor to switch from an open-loop control mode to a closed-loop control mode when variation amplitudes and trends of a modulation terminal voltage and a floating terminal voltage meet preset conditions; and a detection module electrically connected to the multi-phase stator windings and configured to detect an electrical parameter of each of the multi-phase stator windings during operation of the electric motor, detect a terminal voltage of a stator winding that is connected to the power supply and define the terminal voltage as the modulation terminal voltage, and detect a terminal voltage of a stator winding that is not connected to the power supply and define the terminal voltage as the floating terminal voltage”
These features are not found in the prior art in any form that could anticipate this device. Any combination designed solely to reject the claim would rely heavily on hindsight and would therefore be impermissible.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. See Notice of References Cited. The art cited is generally related to the field of power tools with sensorless, brushless, electric motor and its associated method.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to NICHOLAS E IGBOKWE whose telephone number is (571)272-1124. The examiner can normally be reached on M-F 8 a.m. - 5 p.m..
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Anna Kinsaul can be reached on (571) 270-1926. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/NICHOLAS IGBOKWE/
Examiner, Art Unit 3731
/ANDREW M TECCO/Primary Examiner, Art Unit 3731