Milwaukee Electric Tool Corporation

Douglas R Fieldbinder

Maxwell L Merget

Timothy Ryan Obermann

Jonathan E Abbott

Jacob Paul Schneider

John Stanley Dey, Iv

Benjamin R Suhr

Richard A Ryer

Alexander Huber

Matthew R Polakowski

Gareth J Mueckl

Alex Huber

Ian A Duncan

Carl B Westerby

Alex R Kuhls

Justin A Evankovich

Catherine Kelli Semon

Griffin M Steffy

Lucas A Rutowski

Nikita Bhatt

John S Dey

Systems and methods for braking a power tool motor using a magnetically susceptible fluid. One power tool includes a housing, a motor within the housing, a drive train coupled to the motor, a magnetically susceptible fluid located within the drive train, and an inductor within the housing and configured to introduce a magnetic field to the magnetically susceptible fluid. An electronic controller is connected to the motor and to the inductor and is configured to receive a signal to initiate a braking process, generate, in response to the initiation of the braking process, a control signal for the inductor, and provide the control signal to the inductor to control a viscosity of the magnetically susceptible fluid located within the drive train.

Power tool motor braking using magnetically susceptible fluid

A method for automatic control switching for driving a sensorless motor of a power tool, the method including generating, using a signal generator, a high-frequency injection signal. The method includes coupling, using a coupling circuit, the high-frequency injection signal to an injection coil of the sensorless motor. The method includes decoupling, using a de-coupling circuit, a response to the high-frequency injection signal from a phase coil of the sensorless motor. The method includes determine a sensorless motor condition based upon the response of the injection coil to the high-frequency injection signal. The method includes driving, using a controller of the power tool, the sensorless motor based upon the sensorless motor condition.

Sensorless motor control for a power tool

A power tool including a housing, a brushless direct current (DC) motor, an impact mechanism including a hammer and an anvil, an output drive device, a position sensor, and a controller. The position sensor is adjacent to a relief feature, which may be a recessed relief feature or a raised relief feature, and is configured to generate an output signal indicative of a position of the anvil. The controller is configured to calculate a drive angle based on the determined position of the anvil, and control the brushless DC motor based on the drive angle of the anvil.

Systems and methods for detecting anvil position using a relief feature

A power tool including a housing, a brushless direct current (DC) motor, an impact mechanism including a hammer and an anvil, an output drive device, a position sensor, and a controller. The power tool also includes a target positioned on a shaft, a magnetic shield positioned on the shaft between the target and the anvil, and a position sensor. The position sensor includes an inductive sensor, a first transmitting circuit trace, and a first receiving circuit trace. The controller is configured to calculate a drive angle based on the determined position of the anvil, and control the brushless DC motor based on the drive angle of the anvil.

Systems and methods for detecting anvil position using an inductive sensor

A device, such as a power tool, configured to receive a battery pack that is operable to determine a type of battery pack that is attached to the device. When the battery pack is connected to the device, the device is configured to determine an impedance of the battery pack. Based on the determined impedance of the battery pack, the device is capable of detecting the particular type of battery pack that has been attached. In some embodiments, the device is configured to be controlled based on the type of battery pack that has been detected by the device.

Detecting battery pack type based on battery pack impedance

A power tool including a housing, an input, a gear train, a motor at least partially supported by the housing and coupled to the gear train, and a controller including a processor and a memory. The controller is coupled to the input and the motor and is configured to receive an input signal from the input, determine an operating direction and an operating speed based on the input signal, cause the motor to rotate the gear train in a direction opposite the operating direction for a predetermined amount of rotation, and cause the motor to rotate in the operating direction at the operating speed.

Maximum power tool startup torque

Kickback control methods for power tools. One power tool includes a movement sensor configured to measure an angular velocity of the housing of the power tool about the rotational axis. The power tool includes an electronic processor coupled to the switching network and the movement sensor and configured to implement kickback control of the power tool. To implement the kickback control, the electronic processor is configured to control the switching network to drive the brushless DC motor, receive measurements of the angular velocity of the housing of the power tool from the movement sensor, determine that a plurality of the measurements of the angular velocity of the housing of the power tool exceed a rotation speed threshold, and control the switching network to cease driving of the brushless DC motor in response to determining that the plurality of the measurements of the angular velocity exceed the rotation speed threshold.

Kickback control methods for power tools

One embodiment provides a battery pack including a housing, a plurality of battery cells supported by the housing, and a terminal block. The terminal block is configured to be coupled to a power tool to provide operating power from the plurality of battery cells to the power tool. The terminal block has a positive power terminal, a charging terminal, and a ground terminal. The battery pack also includes a charging circuit provided between the charging terminal and the plurality of battery cells. The charging circuit is configured to receive and transfer charging current above 12 Amperes to the plurality of battery cells during charging. The charging circuit includes a charging switch and a fuse coupled between the charging terminal and the charging switch.

Fast-charging battery pack including a charging switch

A trigger assembly for a power tool includes a housing, a moveable plunger extending from a surface of the housing, the movable plunger includes a first end disposed externally from the housing and a second end disposed internally within the housing. The trigger assembly further includes a trigger shoe coupled to the first end of the moveable plunger, and an arm including a first side that is moveably connected to the second end of the moveably plunger and a second side that is coupled to a magnet. The trigger assembly also includes a sensor configured to sense a magnetic field of the magnet. Movement of the trigger shoe rotates the magnet, and alters the magnetic field sensed by the sensor.

Contactless trigger with rotational magnetic sensor for a power tool

Communication systems described herein may include a wireless charging device with a plurality of charging stations. The wireless charging device may communicate with a first battery pack via at least one of a wireless communication device and a first battery pack detection sensor of a first charging station. The wireless charging device may communicate with a second battery pack via at least one of the wireless communication device and a second battery pack detection sensor of a second charging station. The wireless charging device may determine that the first battery pack was manufactured by a different manufacturer than the second battery pack. The wireless charging device may communicate status information to an external device for display by the external device. The status information may include a first manufacturer of the first battery pack and a second manufacturer of the second battery pack that is different than the first manufacturer.

Universal wireless charging of power tool battery packs

A rotary power tool including a gear case, an output shaft extending from the gear case, and a drive mechanism configured to provide torque to the output shaft, causing the output shaft to rotate. The rotary power tool further includes a clutch mechanism between the output shaft and the drive mechanism. The clutch mechanism includes a compression spring and is configured to limit the amount of torque provided by the output shaft. The rotary power tool further includes a sensor positioned on a neck portion of the gear case subject to strain imparted by the compression spring, and an electronic control unit configured to receive an output signal from the strain gauge and determine a torque setting of the clutch mechanism based on the output signal.

Powered screwdriver including clutch setting sensor

A power tool that includes a motor and a printed circuit board ('PCB'). The motor includes a rotor and a stator. The stator includes a plurality of stator terminals. The PCB is electrically connected to the stator. The PCB includes a switch and an embedded busbar. A first end of the embedded busbar is electrically connected to the switch. The embedded busbar extends away from the PCB. A second end of the embedded busbar electrically connects to a stator terminal of the plurality of stator terminals for providing power to the motor using the switch. The embedded bus bar is embedded between two layers of the printed circuit board.

Power tool printed circuit board including embedded busbars

Fast-charging battery pack

Methods and power tools for sensorless motor control. One embodiment provides a method for automatic control switching for driving a sensorless motor () of a power tool (). The method includes determining, using a motor controller (), a first load point based on user inputs () and determining, using the motor controller (), a first motor control technique corresponding to the first load point. The method also includes driving the motor () based on the first motor control technique. The method further includes determining, using the motor controller (), a change from the first load point to a second load point and determining, using the motor controller (), a second motor control technique corresponding to the second load point. The method includes driving the motor () based on the second motor control technique.

Growing community of inventors

Greendale, WI, United States of America

Douglas R Fieldbinder