Patent ID: 8235138
Filing Date: 2012-08-07
Classification: B25D

Abstract:
1. 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 a longitudinal direction of the tool bit in which the tool bit moves to perform a predetermined operation, a handgrip connected to an other end of the housing, and a dynamic vibration reducer including a weight and an elastic element, the elastic element being disposed between the weight and the housing and adapted to apply a biasing force to the weight, wherein the weight reciprocates in the longitudinal direction of the tool bit against the biasing force of the elastic element, whereby the dynamic vibration reducer reduces vibration which is caused in the housing in the longitudinal direction of the tool bit in a working operation, the dynamic vibration reducer is disposed in an internal space defined by the housing, the elastic element includes a first elastic element located on one single side of the weight in the longitudinal direction and a second elastic element located on another single side of the weight in the longitudinal direction, 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 an axial direction of the motor crosses the longitudinal direction of the tool bit, and the dynamic vibration reducer is disposed in a space existing between an axial end of the motor and the inner housing, and the first and second elastic elements each include two separate elastic elements flanking the corresponding single side of the weight, the two elastic elements do not overlap each other in the longitudinal direction of the tool bit and in plan view of the dynamic vibration reducer.