Patent ID: 8127862

Claim:
A power tool comprising: a motor; an internal mechanism driven by the motor; a housing that houses the motor and the internal mechanism; a tool bit disposed in one end of the housing and driven by the internal mechanism in the longitudinal direction of the tool bit to perform a predetermined operation; a handgrip connected to the other end of the housing; and a dynamic vibration reducer including a weight and an elastic element, the elastic element includes two springs disposed on one end of the weight in the longitudinal direction and two springs disposed on the other end of the weight in the longitudinal direction, the two springs on the one end being separate from the two springs on the other end, wherein the elastic element is disposed between the weight and the housing and adapted to apply a biasing force to the weight, the weight reciprocates in the longitudinal direction of the tool bit against the biasing force of the elastic element, the dynamic vibration reducer reduces vibration which is caused in the housing in the longitudinal direction of the tool bit in the working operation, and the dynamic vibration reducer is disposed by utilizing an internal space defined by the housing, and wherein the housing includes an inner housing that houses the internal mechanism and an outer housing that houses the inner housing and the motor such that the axial direction of the motor crosses the longitudinal direction of the tool bit, and the dynamic vibration reducer is disposed by utilizing a space existing between an outer wall surface of a side region of the inner housing and an inner wall surface of a side region of the outer housing and extending in the longitudinal direction of the tool bit.