Patent ID: 7469753
Filing Date: 2008-12-30
Classification: B23B,B25B,B25F,F16D,Y10T

Abstract:
1. A power tool comprising: a housing and a motor supported by the housing and including a motor shaft; a spindle supported by the housing for rotation about an axis; and a drive assembly provided between the spindle and the motor shaft such that the spindle is drivingly connectable to the motor shaft to drive a tool element, the drive assembly including: a first clutch assembly having an engaged configuration, in which the first clutch assembly transfers a drive force from the motor shaft to the spindle, and a disengaged configuration, in which the first clutch assembly prevents the transfer of the drive force from the motor shaft to the spindle, the first clutch assembly being movable from the engaged configuration toward the disengaged configuration when a torque exerted on the spindle exceeds a torque limit; and a second clutch assembly having an engaged configuration, in which the second clutch assembly transmits the drive force from the motor shaft to the spindle, and a disengaged configuration, in which the second clutch assembly prevents the transmission of the drive force from the motor shaft to the spindle, the second clutch assembly being movable from the disengaged configuration toward the engaged configuration when the tool element engages a workpiece, wherein the first clutch assembly includes a cage and a clutch member supported in the cage and configured to selectively transfer the drive force from the motor shaft to the spindle.