Abstract: The air hammer is of the type employing a body having a first portion with a central bore and a piston reciprocable in the bore by pressurized air under control of an automatic valve. The body has a second or muffler portion which embraces the first portion and is operative to muffle the noise created by exhaust air from the bore. The muffler portion is provided with pressurized air passage means through which the pressurized air must pass for causing operation of the piston. The passage means are so arranged that removal of the muffler portion from the body disrupts the supply of pressurized air to the piston and thereby renders the hammer inoperative. Headers are provided on the ends of the body and are drawn tightly against the ends of the muffler portion by tie bolts which extend through through-passages, respectively, in the muffler portion.

Abstract: The air hammer is adapted to be connected to a source of pressurized air and has an exhaust passage means controlled by a settable exhaust valve. Reciprocation of the hammer is controlled by an automatic valve when the hammer is active. The exhaust passage means and exhaust valve are arranged so that in a first set position of the exhaust valve, it renders the hammer operative by the pressurized live air under the control of the automatic valve, and in a second set position of the exhaust valve, it renders the hammer inoperative by the pressurized live air. Further, in said second position of the exhaust valve, it admits live air from said source to the tool continuously in sufficient volume to blow out of a hole, in which the tool is operating, particulate matter theretofore produced in the hole by the tool. In the first position, the exhaust valve stops the flow of live blow-out air to the tool.