US 12,015,364 B2
Impact tools and control modes
Brian E. Friedman, Baltimore, MD (US); Peter Hague Wadeson, Silver Spring, MD (US); Eric Louis Kunz, Shrewsbury, PA (US); Bhanuprakash Villuri, Towson, MD (US); Tyler Petrus, Baltimore, MD (US); and Wing W. Lin, Bel Air, MD (US)
Assigned to BLACK & DECKER INC., New Britain, CT (US)
Filed by BLACK & DECKER INC., New Britain, CT (US)
Filed on Jan. 7, 2022, as Appl. No. 17/571,246.
Application 17/571,246 is a continuation of application No. 17/551,596, filed on Dec. 15, 2021, granted, now 11,855,567, issued on Dec. 26, 2023.
Claims priority of provisional application 63/127,595, filed on Dec. 18, 2020.
Prior Publication US 2022/0200511 A1, Jun. 23, 2022
Int. Cl. H02P 29/024 (2016.01); B25B 21/02 (2006.01); B25B 23/147 (2006.01); B25D 17/06 (2006.01); H02P 3/06 (2006.01); H02P 21/02 (2006.01)
CPC H02P 29/027 (2013.01) [B25B 21/02 (2013.01); B25B 21/023 (2013.01); B25B 21/026 (2013.01); B25B 23/1475 (2013.01); B25D 17/06 (2013.01); H02P 3/06 (2013.01); B25D 2250/095 (2013.01)] 24 Claims
OG exemplary drawing
 
1. A power tool comprising:
a housing;
a brushless motor received in the housing;
a power switch coupled to the housing and actuatable by a user;
a controller configured to control power delivery to the motor in response to actuation of the power switch;
an output spindle configured to rotate when the motor is energized; and
an impact mechanism configured to be driven by the motor and configured to rotationally drive the output spindle, the impact mechanism configured to selectively apply rotational impacts to the output spindle when a torque on the output spindle exceeds a torque threshold,
wherein the controller is configured to apply a current limit to current delivered to the motor over a plurality of current cycles by turning off or reducing power to the motor for a time period if the current exceeds the current limit during a current cycle and then restoring power delivery to the motor at the end of the time period,
wherein the current limit is selected and the controller is operable so that, when driving a fastener into a hard joint, the current limit is reached while applying rotational impacts, and the impact mechanism continues to apply rotational impacts to the fastener while the current limit is applied.