Patent ID: 7588097

Claim:
A power impact tool to perform a predetermined operation on a workpiece by using a striking movement of a tool bit in its axial direction comprising: a motor, a rotating shaft that is disposed substantially parallel to the axial direction of the tool bit and rotationally driven by the motor, a swinging member that is supported by the rotating shaft to swing in the axial direction of the rotating shaft by rotation of the rotating shaft, the swinging member having an upper end region and a lower end region, as viewed in the axial direction of the tool bit, the upper end region extending in a direction substantially perpendicular to the axial direction of the rotating shaft, a tool driving mechanism that is connected to the upper end region of the swinging member, the tool driving mechanism linearly moving in the axial direction of the tool bit by the swinging movement of the swinging member to linearly drive the tool bit, and a counter weight that reduces vibration caused in the axial direction of the tool bit during the operation of the power impact tool, wherein: the counter weight is disposed in a region higher than the lower end region of the swinging member, as viewed from the axial direction of the tool bit, and a lower end of the counter weight is connected to the lower end region of the swinging member and the counter weight extends upward from the connection between the counter weight and the swinging member and has a pivot point in an extending end portion, and when the swinging member swings, the counter weight is driven by the swinging member to pivot about the pivot point in the axial direction of the tool bit, thereby reducing vibration caused in the axial direction of the tool bit.