Patent ID: 7900714

Claim:
A power tool comprising: a motor having an output shaft; a transmission having a plurality of planetary transmission stages comprising a first planetary transmission stage and a second planetary transmission stage, each of the plurality of planetary transmission stages comprising a sun gear, a planet carrier, a plurality of planet gears journally supported by the planet carrier and meshingly engaged to the sun gear, and a ring gear having internal teeth that are engaged by the plurality of planet gears, the sun gear of the first planetary transmission stage being directly driven by the output shaft of the motor, the ring gear of the first planetary transmission stage not being shared by another of the plurality of planetary transmission stages, the first planetary transmission stage receiving an input torque from the motor and producing an intermediate output torque in response thereto that is transmitted to the second planetary transmission stage; an output member drivingly coupled to the transmission on a side of the transmission opposite the motor; and a clutch assembly that comprises a clutch profile and an engagement assembly, the clutch profile being coupled to a side of the ring gear of the first planetary transmission stage that is opposite the motor, the engagement assembly being disposed between the ring gear of the first planetary transmission stage and the output member, the engagement assembly including a follower member, a follower spring and an adjustment collar, the follower spring applying a biasing force that is transmitted to the follower member to bias the follower member into engagement with the clutch profile, the adjustment collar being movable to change a magnitude of the biasing force, the follower assembly cooperating with the clutch profile to inhibit rotation of the ring gear of the first planetary transmission stage only when the magnitude of the intermediate output torque is less than a selected maximum torque; wherein rotation of the ring gear of the first planetary transmission stage limits a maximum tool torque that is output through the output member to halt rotation of the output member.