Patent ID: 8196674

Claim:
An impact tool performing a predetermined hammering operation on a workpiece by a striking movement of a tool bit in an axial direction of the tool bit, the impact tool comprising: a motor that drives the tool bit, a tool body that houses the motor, a dynamic vibration reducer that reduces vibration of the tool body during hammering operation, the dynamic vibration reducer comprising a weight that can linearly move in the axial direction of the tool bit and a sleeve that forcibly drives the weight, and a driving mechanism part that is driven by the motor and forcibly drives the dynamic vibration reducer by applying an external force other than vibration of the tool body to the sleeve in order to forcibly drive the dynamic vibration reducer during hammering operation, wherein: at least one of the dynamic vibration reducer and the driving mechanism part is mounted to the tool body in a form of an assembly in which at least one of a plurality of component parts forming the dynamic vibration reducer and a plurality of component parts forming the driving mechanism part are assembled in advance, and the driving mechanism part includes: a cam shaft that is rotationally driven by the motor, an eccentric cam that is integrally formed or fixedly connected with the cam shaft, and pins disposed in the axial direction of the tool bit, the pins being caused to linearly move in the axial direction of the tool bit by rotation of the eccentric cam in order to forcibly drive the dynamic vibration reducer, wherein at least one of the ins is mounted transversely to the axis of the cam shaft.