US Patent 7422075 Rotary tool

An overload clutch assembly for a power tool having two torque settings through which rotary drive is transmitted to a spindle. The overload clutch assembly is capable of being between switched between the two torque settings by at least one actuator. The clutch assembly comprises a carrier rotationally mounted on a output clutch spindle; a first clutch plate operational for transmitting torque below a first level; and a second clutch plate operational for transmitting torque below a second level higher than the first; and characterised in that, when the overload clutch is in the higher torque setting, the torque is transferred from the carrier to the output clutch spindle via the second clutch plate only.