Patent attributes
A rotary impact tool including a motor having a motor shaft that produces a rotational output to drive a gear assembly and a drive assembly driven by the gear assembly. The drive assembly including a hammer coupled to the motor shaft and an anvil configured to receive an impact from the hammer. The rotary impact tool includes a torque stick coupled to the anvil and configured to limit the amount of deliverable torque to a workpiece in accordance with a torsional stiffness of the torque stick, a position sensor to detect angular displacement of the anvil, and a controller in electrical communication with the position sensor. The controller calculates torque delivered to the workpiece from the impact by multiplying the torsional stiffness of the torque stick and the signal from the position sensor, and control the motor based on the torque delivered to the workpiece.
