Patent ID: 8267191

Claim:
An impact tool comprising: an impact mechanism provided in a housing and comprising an impactor configured to strike a bit and a piston configured to cause the impactor to move in accordance with a motion of the piston; a crank mechanism in which an eccentric pin provided at a motor-driven rotatable crank shaft is connected to the piston by a connecting rod so as to convert a rotation of the crank shaft into a reciprocating motion of the piston; a vibration damping mechanism including a counterweight configured to move in synchronization with the crank mechanism so as to reduce vibration by canceling out a shift in the center of gravity derived from the reciprocating motion of the piston; and an inlet configured to serve as a channel for grease, the inlet formed above the crank mechanism in the housing and configured to be closed by a cap that is attachable to and detachable from the inlet, wherein at least part of the vibration damping mechanism, the at least part of the vibration damping mechanism including the counterweight, is mounted to the cap in such a manner that attachment of the cap brings the at least part of the vibration damping mechanism into the housing, the at least part of the vibration damping mechanism configured to be taken in and out of the housing through the inlet with attachment and detachment of the cap to and from the inlet.