Convertible rotary impact hammer drill

摘要

In a rotary hammer drill in which a tool is driven in rotation by rotating the cylinder housing a driver piston and a striker, the hammering effect is rendered inoperative by providing in the well of the barrel an aperture which is axially positioned so as to vent the space between the driver and striker to the atmosphere. A sleeve is mounted on the external surface of the barrel and is axially movable to blank off the aperture or to place it in communication with the ambient atmosphere.