To provide a reduced noise type vibrating drill that can provide sufficient noise reducing effect without cost increase, taking no special manufacturing trouble, and moreover without enlarging a machine or impairing usability.
In this drill, a piston provided movably forward and backward in a cylinder of a drill head is operated back and forth by fluid pressure, and the impact force is transmitted to a bit through a drilling rod to drill a hole. The piston and the drilling rod whose tip is mounted with the bit are integrally connected. The forward and backward operation of the piston by the fluid pressure is performed by providing the outer periphery of the piston with a rotary valve rotated around the piston and changing a pressure fluid alternately to the piston rear chamber and front chamber of the cylinder by the rotation of the rotary valve.
MOTOTANI KAZUHEI
IWASAKI TSUNEO
HAGA KAZUO
HONGO MASANAO
