US 11,986,932 B2
Torque stick for a rotary impact tool
Jonathan E. Abbott, Milwaukee, WI (US); Jacob P. Schneider, Cedarburg, WI (US); Peter Malak, Waukesha, WI (US); and Christopher S. Hoppe, Milwaukee, WI (US)
Assigned to MILWAUKEE ELECTRIC TOOL CORPORATION, Brookfield, WI (US)
Filed by MILWAUKEE ELECTRIC TOOL CORPORATION, Brookfield, WI (US)
Filed on Oct. 8, 2021, as Appl. No. 17/497,753.
Claims priority of provisional application 63/089,856, filed on Oct. 9, 2020.
Prior Publication US 2022/0111502 A1, Apr. 14, 2022
Int. Cl. B25B 23/00 (2006.01); B25B 21/02 (2006.01); B25B 23/147 (2006.01)
CPC B25B 23/1475 (2013.01) [B25B 21/026 (2013.01); B25B 23/0021 (2013.01)] 22 Claims
OG exemplary drawing
 
1. A rotary impact tool comprising:
a housing;
a motor within the housing, the motor including a motor shaft that produces a rotational output to drive a gear assembly;
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;
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 and configured to:
receive a signal from the position sensor based on rotation of the anvil,
calculate 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.