Patent ID: 6687567
Filing Date: 2004-02-03
Classification: B25B

Abstract:
A power tool adapted to tighten a fastener, comprising;a motor, means for generating an elevated torque coupled to the motor, a trigger switch for energizing the motor, a sensor detecting when the means for generating an elevated torque has begun to operate and generate the elevated torque and a microprocessor in communication with the sensor, the trigger switch and the motor, wherein the microprocessor controls the motor according to either (1) a measurement mode, in which the microprocessor drives the motor while the trigger switch is held in the ON position and measures a time period from when a first impact is detected by the sensor to when the trigger switch is switched to the OFF position or (2) an automatic stop mode, in which the microprocessor drives the motor upon the trigger switch is switched to the ON position, and the microprocessor stops the motor when a predetermined time has elapsed after a first impact was detected by the sensor.