US Patent 9289886 Impact tool with adjustable clutch

An impact tool includes a housing, a motor supported in the housing, an output shaft rotatably supported in the housing about a central axis, an impact mechanism coupled between the motor and the output shaft and operable to impart a striking rotational force to the output shaft, and a clutch mechanism coupled between the impact mechanism and the output shaft. The clutch mechanism is operable in a first mode, in which torque from the motor is transferred to the output shaft through the impact mechanism, and a second mode, in which torque from the motor is diverted from the output shaft toward a portion of the impact mechanism.