Black Decker Inc.

Wing Lin

Jason K Leh

Michael Kenneth Forster

Daniele C Brotto

Brian E Friedman

Tyler Petrus

BhanuPrakash Villuri

Eric Louis Kunz

Peter Hague Wadeson

John D Cox

Shailesh P Waikar

Christopher Wade Shook

Barak N Gohn

Marcell E Coates

Jason D McKillican

Zhi Qu

John Charles Vanko

Scott J Eshleman

Samuel G Woods

Tal Gottesman

Mark T Cherry

Timothy J Seeley

Alexander Manasseh

A system is provided with a set of removable battery packs and a set of power tools each including a motor, a controller, and a battery receiving portion. For each power tool, the controller is configured to identify a type of battery pack coupled to the battery receiving portion and set a conduction band associated with phases of the motor or an advance angle by which phases of the motor are shifted based on the identified type of the battery pack.

Power tool receiving different capacity battery packs

An impact power tool includes a housing, a motor, a controller, an impact mechanism configured to be driven by the motor, and an output spindle configured to receive rotational impacts from the impact mechanism to rotate the output spindle. The controller is configured to detect a first impact of the rotational impacts or to detect when the motor speed drops below a speed threshold value. The controller is configured to control the motor to have a first non-zero target rotational speed using closed loop control for a predetermined time period after the first impact is detected or when the motor speed dropping below the speed threshold value is detected. The controller is configured to control the motor to have a second non-zero target rotational speed using the closed loop control after the predetermined time period. The first non-zero target rotational speed is less than the second non-zero target rotational speed.

Impact tools and control modes

A power tool includes a housing, a brushless motor received in the housing, a power switch coupled to the housing and actuatable by a user, a controller configured to control power delivery to the motor in response to actuation of the power switch, and an output spindle configured to rotate when the motor is energized. The controller is configured to maintain an amount of current delivered to the motor to be less than or equal to a current limit by turning off or reducing power to the motor for a time period if the current exceeds the current limit and then restarting power delivery to the motor. The time period is greater than the duration of one full current cycle.

An impact power tool includes a housing, a motor, a controller, an output member configured to be rotated when the motor is energized, and an impact mechanism configured to rotationally drive the output member. The impact mechanism is configured to selectively apply rotational impacts to the output member when a torque on the output member exceeds a torque threshold. The controller is configured to control the motor during a first phase of operation with open loop control and a baseline conduction band and advance angle setting when a sensed tool operation parameter is one of above or below a threshold value. The controller is configured to control the motor during a second phase of operation with closed speed loop control and an increased conduction band and advance angle setting when the sensed tool operation parameter is the other of above or below the threshold value.

A control unit for a brushless DC motor of a power tool having a rotor and a stator is provided. The control unit detects an initial position of the rotor, commutates the motor beginning at the initial position of the rotor using a low-speed motor commutation scheme until an output speed of the rotor exceeds a speed threshold, and commutates the motor based on a back-electromotive force (back-EMF) voltage of the motor after the output speed of the rotor exceeds the speed threshold. In the low-speed commutation scheme, the control unit applies a first set of voltage pulses to a present sector and a second set of voltage pulses to a next sector, and detects a transition of the rotor from the present sector to the next sector based on motor current measurements associated with the first set of voltage pulses and the second set of voltage pulses.

Low-speed sensorless brushless motor control in a power tool

A system is provided with a set of removable battery packs and a set of power tools each including a motor, a controller, and a battery receiving portion. For each power tool, the controller is configured to identify a type of battery pack coupled to the battery receiving portion and limit a maximum amount of electric current drawn from the battery pack by the motor based on the identified type of the battery pack. The greater a ratio of an impedance of the motor to an impedance of the battery pack, the less the controller limits the maximum amount of electric current drawn from the battery pack such that for a given battery pack of the set of removable battery packs, the lower the impedance of the motor, the more current the motor draws from the given battery pack.

A power tool is provided including a brushless motor having a stator defining a plurality of phases, a rotor rotatable relative to the stator, and power terminals electrically connected to the phases of the motor. A power unit is provided including power switches. A control unit is interfaced with the power unit to output a drive signal to one or more of the motor switches to drive the phases of the motor over a series of sectors of the rotor rotation. The control unit is configured detect incorrect rotation of the rotor by applying a first series of voltage pulses to a present sector and a second series of voltage pulses to a previous sector, measuring motor currents associated with the first and second series of voltage pulses, and comparing corresponding motor current measurements to detect a transition from the present sector to the previous sector.

A power tool is provided, including a housing; a brushless DC (BLDC) motor arranged within the housing, the motor including a stator and a rotor rotatably disposed within the stator; a power module electrically disposed between the motor and a power supply, the power module including power switches; an actuator engageable by a user; and a control module configured to control a switching operation of the power switches to begin supply power to the motor when the actuator is engaged. The control module monitors engagement and disengagement events of the actuator, and ignores a subsequent engagement of the actuator if at least one of number of actuator engagement events and/or number of actuator disengagement events exceeds a predetermined threshold value within a predetermined time.

Sensorless thermal protection for power tools

A method is provided for operating a power tool having a motor powered by a battery. The method includes: delivering power from the battery to the motor in accordance with an operator input; detecting a condition of the power tool indicating a shutdown of the power is imminent; and fading the power delivered from the battery to the motor, in response to the detected condition, through the use of a controller residing in the power tool.

Controlled power fade for battery power devices

Controlled power fade for battery powered devices

A power tool including a motor, an input unit such as a variable-speed trigger switch, and a controller is provided. The controller controls the speed of the motor as a function of the input level indicated by the electrical signal from the input unit. The function is a first expression within a first predetermined range of the input level and a second expression within a second predetermined range of the input level, where the second expression corresponds to a polynomial of a second degree or higher and is different from the first expression.

Growing community of inventors

Bel Air, MD, United States of America

Wing Lin