Patent ID: 11872680
Assignee: BLACK & DECKER, INC.
Field: Machine tools (Mechanical engineering)
Classification: CPC B | IPC B

Claim 0:
1. An impact power tool comprising:
a housing;
a motor disposed in the housing and including a motor output shaft;
a transmission including a transmission output shaft and an input member rotatably drivable by rotation of the motor output shaft;
a rotary impact assembly including a cam shaft extending along and rotatable about an axis, a hammer coupled to the cam shaft for axial and rotational movement relative to the cam shaft, an anvil rotatable about the axis, and a spring biasing the hammer toward the anvil;
a tool output shaft partially or fully received in the housing and rotatable by rotation of the anvil; and
a coupler removably coupling the cam shaft to the transmission output shaft,
wherein when torque on the tool output shaft is less than or equal to a first threshold, the transmission output shaft, the cam shaft, the hammer, and the anvil rotate together to transmit torque to the tool output shaft,
wherein when torque on the tool output shaft is above the first threshold, the hammer moves along the cam shaft away from the anvil by at least a first distance and applies intermittent rotary impacts to the anvil and the tool output shaft, and
wherein when the hammer moves along the cam shaft away from the anvil by at least a second distance greater than the first distance, the coupler decouples the transmission output shaft from the cam shaft, interrupting torque transmission to the tool output shaft.