The Back Hammer is designed to help to free a DTH hammer and drill pipes that have jammed in the drill hole. It can also be used the hammer down or withdraw casings. The Back Hammer is mounted between the rotating unit and the drill pipes or between drill pipes and the hammer. When compressed air let the check valve be opened, the piston in the back hammer starts to strike the support bar and thus the impact and return strokes of the piston in controlled by means of directional ducts in the piston and the control tube. On the impact stroke, the piston strikes the support bar which transmit the impact energy into the drill string.

The return stroke of the piston is braked by an air cushion and the air cushion chamber and the piston will move back to striking position. The exhausted air from the back hammer is expelled through the holes at the shoulder of the back hammer. For hammering down casing, the back hammer is simply mounted upside down, whereupon the impact energy is directed downwards. Wildcat Back hammer is combined with a shock absorbing unit to protect the equipment’s rotation head threads while working.