Power tool with force sensing electronic clutch

摘要

A method of limiting an output torque in a power tool having a housing (12), a motor (20) and a transmission (22) disposed in the housing (12), and an output end effector (24) coupled to the transmission (22), the method comprising providing a force sensor (42) coupled to a substantially stationary element (44) of the transmission (22); receiving a first electronic signal from the force sensor (42) that corresponds to a value of a reaction torque transmitted from the end effector (24) to the substantially stationary element (44) of the transmission; comparing the first electronic signal to a second electronic signal corresponding to a desired threshold torque value; and initiating a protective operation when a value of the first electronic signal indicates that the reaction torque has exceeded the desired threshold torque value.