Abstract: A power tool includes a housing, a motor disposed in the housing, a transmission disposed in the housing and coupled to the motor, an output end effector coupled to the transmission, a control circuit for controlling power delivery from a power source to the motor, and a force sensing electronic clutch including a force sensor coupled to a substantially stationary element of the transmission. The force sensor senses a reaction torque transmitted from the end effector to at least a portion of the transmission. The sensor is configured to generate a first electronic signal corresponding to an amount of the reaction torque. The control circuit compares the first electronic signal with a second electronic signal corresponding to a desired threshold torque value, and initiates a protective operation when a value of the first electronic signal indicates that the reaction torque has exceeded the desired threshold torque value.

Abstract: Provided are various embodiments of structures that may utilized in a power driver, particularly in a power driver having an optional reciprocating “hammer” action, that may be utilized for retaining an outer bearing during driver assembly and during subsequent operation of the power driver. In particular, the disclosed structures provide one or more surfaces, particularly inner peripheral surfaces, that limit the outward axial movement of the bearing. These structures may include combinations of surfaces defined by retaining members including, for example, one or more flanges, clips and threaded members, an input shaft, biasing mechanisms, typically a spring or other resilient structure, and chuck shield assemblies for positioning the outer bearing within the power driver.