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 § 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.
Claims 1-2, 5-8 and 10-12 are rejected under 35 U.S.C. 103 as being unpatentable over Heidrich US publication no.: US 2004/0113576 A1 in view of Obermann et al. US publication no.: US 2022/0241951 A1.
Regarding claims 1 and 7, Heidrich teaches, A sensorless motor control system, comprising: a drive unit including a motor having three phase windings and a rotor (see motor 10, figure 1 and paragraph 17 which includes rotor 13 and stator 12), and an actuation circuit (switching device 14, figure 3) electrically connected to said three phase windings, and including three switch units that are electrically connected respectively to said three phase windings, each of said three switch units including a high-side switch and a low-side switch that are connected in series and that have a common node, said common node being electrically connected to a respective one of said three phase windings (see figures 1-2 where the actuation unit includes high-side and low-side switches); a detection unit including a current detection circuit for detecting a current of said motor (see paragraphs 22-23, where the measurements of the current is disclosed); and a control unit (control device 15, figure 1) electrically connected to said power unit, said actuation circuit, and said detection unit, wherein said control unit is configured to, when said motor is being activated, control said actuation circuit to alternately actuate said high-side switches respectively of said three switch units and alternately actuate said low-side switches respectively of said three switch units during a plurality of detection cycle periods in such a manner that, said high-side switch of one of said three switch units and said low-side switch of a different one of said three switch units are actuated during each of the plurality of detection cycle periods (see paragraphs 22-23 where the current is applied to the high-side and low-side switching controlled is seen which can be further seen in figure 3); wherein said control unit is further configured to, during each of the plurality of detection cycle periods, when determining that the current of said motor fulfills a predetermined condition (see “current rise times” in paragraphs 22-23), stop actuating (see paragraph 23 where the current impulse have “decayed” prior to the next test current impulse is intruded) said high-side switch of said one of said three switch units and said low-side switch of said different one of said three switch units, and record an actuation (see current rise times that are saved in the memory, paragraph 23) duration for which said high-side switch of said one of said three switch units and said low-side switch of said different one of said three switch units are actuated during the detection cycle period; and wherein said control unit is further configured to determine a position of said rotor of said motor (see paragraph 22 where the “smallest current rise time” corresponds to the rotor position) based on one of said high-side switches of said three switch units and one of said low-side switches of said three switch units that correspond to a shortest one of the actuation durations that were recorded respectively for the plurality of detection cycle periods.
Heidrich is silent on specifically teaching: a power tool; a power unit including a battery pack for providing power.
However Obermann et al. is in the same field of art and teach: a power tool (see figure 1); a power unit including a battery pack for providing power (see paragraph 31).
In view of Obermann et al.’s teachings, it would’ve been obvious to one with the ordinary skills in the art, before the effective filing date of the invention, with the apparatus as taught by Heidrich to include; a power tool; a power unit including a battery pack for providing power, for the purpose of providing a variant apparatus to be controlled.
Regarding claims 2 and 8, Heidrich teaches, the sensorless motor control system as claimed in claim 1, wherein the predetermined condition is the current of said motor being greater than a predetermined current value (see paragraph 21 where the predetermined condition corresponds to current threshold).
Regarding claims 5 and 11, Heidrich teaches, the sensorless motor control system as claimed in claim 1, wherein said motor is a three-phase motor, a number of possible unique combinations of said high-side switch of said one of said three switch units pairing with said low-side switch of said different one of said three switch units is six, and a number of the plurality of detection cycle periods is six; and wherein said control unit is configured to control said actuation circuit to actuate the possible unique combinations sequentially, one at a time, during each of the plurality of detection cycle period (see figures 3-4 and paragraphs 21-23 where six test current impulses can be seen).
Regarding claims 6 and 12, Obermann et al. teach, the sensorless motor control system as claimed in claim 1, wherein said motor produces a back electromotive force (BEMF) when driven to rotate, and said control unit is further configured to detect the BEMF of said motor (see BEMF detection, paragraphs 39-41), and control said actuation circuit to actuate one of said high-side switches and one of said low-side switches that correspond to a next phase of a rotation phase sequence of said motor after a delay time since said control unit detects a zero-crossing point of the BEMF.
Claims 3-4 and 9-10 are rejected under 35 U.S.C. 103 as being unpatentable over Heidrich US publication no.: US 2004/0113576 A1 in view of Obermann et al. US publication no.: US 2022/0241951 A1 and further in view of Schwarzkopf et al. US Publication no.: US 2010/001971 A1.
Regarding claims 3 and 9, Heidrich as modified is silent on specifically teaching, the sensorless motor control system as claimed in claim 1, wherein each of said three phase windings produces a self-induced voltage during the actuation duration in each of the plurality of detection cycle periods; and wherein each of the plurality of detection cycle periods includes a voltage drop duration taken for the self-induced voltage to drop to a predetermined voltage level after said high-side switch of said one of said three switch units and said low-side switch of said different one of said three switch units stop being actuated.
However, Schwarzkopf et al. is in the same field of art and teach: wherein each of said three phase windings produces a self-induced voltage during the actuation duration in each of the plurality of detection cycle periods; and wherein each of the plurality of detection cycle periods includes a voltage drop duration taken for the self-induced voltage to drop(see freewheeling current to decay, paragraphs 66-70) to a predetermined voltage level (see “threshold value”, paragraph 70) after said high-side switch of said one of said three switch units and said low-side switch of said different one of said three switch units stop being actuated (see paragraphs 70-79, where the determination for next cycle is started).
In view of Schwarzkopf et al.’s teachings, it would’ve been obvious to one with the ordinary skills in the art, before the effective filing date of the invention, with the apparatus as taught by Heidrich to include; wherein each of said three phase windings produces a self-induced voltage during the actuation duration in each of the plurality of detection cycle periods; and wherein each of the plurality of detection cycle periods includes a voltage drop duration taken for the self-induced voltage to drop to a predetermined voltage level after said high-side switch of said one of said three switch units and said low-side switch of said different one of said three switch units stop being actuated., for the purpose of increasing the efficiency of the sensorless drive system.
Regarding claims 4 and 10, Heidrich as modified is silent on specifically teaching, the sensorless motor control system as claimed in claim 1, wherein each of said three phase windings produces a self-induced voltage during the actuation duration in each of the plurality of detection cycle periods; and wherein each of the plurality of detection cycle periods includes the actuation duration, a voltage drop duration, and a buffer duration, where the voltage drop duration is taken for the self-induced voltage to drop to a predetermined voltage level after said high-side switch of said one of said three switch units and said low-side switch of said different one of said three switch units stop being actuated, and the buffer duration is taken for said control unit to actuate one of said high-side switches in a next one of the plurality of detection cycle periods.
However, Schwarzkopf et al. is in the same field of art and teach: wherein each of said three phase windings produces a self-induced voltage during the actuation duration in each of the plurality of detection cycle periods; and wherein each of the plurality of detection cycle periods includes the actuation duration, a voltage drop duration (see freewheeling current to decay, paragraphs 66-70),and a buffer duration (see freewheeling current to decay, pagraph 70), where the voltage drop duration is taken for the self-induced voltage to drop to a predetermined voltage level after said high-side switch of said one of said three switch units and said low-side switch of said different one of said three switch units stop being actuated (see “threshold value”, paragraph 70), and the buffer duration is taken for said control unit to actuate one of said high-side switches in a next one of the plurality of detection cycle periods (see paragraphs 70-79, where the determination for next cycle is started).
In view of Schwarzkopf et al.’s teachings, it would’ve been obvious to one with the ordinary skills in the art, before the effective filing date of the invention, with the apparatus as taught by Heidrich to include; wherein each of said three phase windings produces a self-induced voltage during the actuation duration in each of the plurality of detection cycle periods; and wherein each of the plurality of detection cycle periods includes the actuation duration, a voltage drop duration, and a buffer duration, where the voltage drop duration is taken for the self-induced voltage to drop to a predetermined voltage level after said high-side switch of said one of said three switch units and said low-side switch of said different one of said three switch units stop being actuated, and the buffer duration is taken for said control unit to actuate one of said high-side switches in a next one of the plurality of detection cycle periods, for the purpose of increasing the efficiency of the sensorless drive system.
Conclusion
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/ZOHEB S IMTIAZ/Primary Examiner , Art Unit 2837
