DTH Drilling Hammer

Series QL high air-press DTH Drilling Hammer is designed as a hammer drill. They differ from other rock drills, however, through continuous operation down against the drilling bit.

The compressed gas enters the DTH Drilling Hammer through the drill pipe and then is discharged from the drill bit, and the exhaust gas is used for deslagging. The rotary motion of the hammer is provided by the rotary head, and the shaft thrust is provided by the propeller, which is transmitted to the DTH Drilling Hammer through the drill rod.

The DTH Drilling Hammer comprises a narrow elongated tube which contains an impact piston, internal cylinder, air distributor, check valve. The real, threaded top sub is fitted with a spanner slot and coupling thread for connection to the drill tubes. The forward part, the driver check, also fitted with thread, enclose the splines-equipped bit shank and thansfers feed force as well as rotation to the water well drilling bit. 

A stop ring limits axial movements of the drill bit. The purpose of the check valve is to prevent impurities from penetrating the DTH Drilling Hammer when pressed air is shut off. During drilling, the drill bit is with drawn inside the water well drilling hammer pressed against the drive chuck. The piston strikes directly against impact surface of the shank of the bit. Air blowing occurs when the bit loses contact with the bottom of the hole.

The stop ring and check valve work together to provide maximum efficiency. The stop ring ensures that the drill bit does not move too far into the hole, while the check valve prevents impurities from entering the DTH Drilling Hammer when the air pressure is shut off. During drilling, the drill bit is held firmly in place against the drive chuck by the force of the air pressure, and the piston strikes the impact surface of the bit shank to propel it into the hole. When the bit loses contact with the bottom of the hole, air blowing occurs, which helps to cool the bit, reduce friction, and clear debris away from the drill bit.