Patent ID: 7506694

Claim:
A power tool comprising: a motor; a tool holder for holding an output member; a transmission for transmitting rotary torque from the motor to the tool holder, the transmission comprising a first transmission portion and a second transmission portion and a clutch assembly located between the first transmission portion and the second transmission portion; the clutch assembly comprising: a clutch shaft; an output gear for driving the second transmission portion with rotary torque transmitted across the clutch assembly, the output gear rotationally fixed relative to the clutch shaft; an input gear for receiving rotary torque from the first transmission portion, the input gear located around and rotatable relative to the clutch shaft; a first slip disc and a first clutch mechanism operable for transmitting rotary torque not exceeding a first predetermined torque limit from the input gear to the clutch shaft; a second slip disc and a second clutch mechanism operable for transmitting rotary torque not exceeding a second predetermined torque limit from the input gear to the clutch shaft, the second predetermined torque limit being greater than the first predetermined torque limit; an actuator mechanism for selectively engaging the second slip disc for transmitting rotary torque, not exceeding the second predetermined torque limit, from the input gear to the clutch shaft.