Black Decker Inc.

Sona R Mathew

Jason D McKillican

Madhur M Purohit

Daniel F Nace

Ross Arthur Billings

Christopher T King

Robert J Cirincione, Ii

Michael P Sikora

Wesson Charles

BhanuPrakash Villuri

Jason Thrush

Paul J Korick

Alexander P Davidson

Michael Allen

Curtiss Morton

A method of operating a power tool having a motor and a controller is provided. The method includes: setting a protection time limit associated with a condition of the motor; taking protective action to shut down the motor if the condition of the motor persists for a duration of the protection time limit; and in response to occurrence of the condition during a start-up period of operation of the motor, extending the protection time limit for a duration of a constant-clutch time period to allow an output speed of the motor to reach or exceed a speed threshold, and taking protective action to shut down the motor if the output speed of the motor remains below the speed threshold for the duration of the constant-clutch time period.

Constant-clutch operation at power tool start-up

A power tool includes a housing, a motor disposed in the housing, a motor controller disposed in the housing and electrically coupled to the motor, and a transmission disposed in the housing and coupled to the motor. A tool bit holder is rotatably driven by the motor via the transmission and receives a tool bit for rotatably driving threaded fasteners. A power switch and an electronic model select switch are actuatable from outside the housing and are coupled to the motor controller. The power switch controls power delivery to the motor. The electronic mode select switch is configured to select between at least a first mode of operation in which power delivery to the motor is controlled by actuation of the power switch and an electronic lock on mode in which continuous power is delivered to the motor upon a single actuation and release of the power switch.

Power tool with multiple modes of operation and ergonomic handgrip

A method of operating a power tool having a motor and a controller is provided. The method includes: receiving a position of a variable-speed input mechanism mounted on the power tool; determining a target speed of the motor corresponding to the position of the variable-speed input mechanism; determining an underspeed threshold corresponding to the target speed; determining a rotational speed of the motor; and interrupting a supply of power to the motor if the rotational speed of the motor is less than the underspeed threshold.

Under-speed and closed-loop speed control in a variable-speed power tool

Growing community of inventors

Towson, MD, United States of America

Sona R Mathew