Hydraulic Dampening System

The action of the dampening piston, not only absorbs the lost part of reflected energy but ensures a constant thrust onto the tools:

• optimum shock wave transmission
• protection of the drifter and tools
• reduced vibrations

Progressive Blow Energy

The unique design of the piston generates a perfect, long shock wave of a trapezoidal shape:

• better transmission of energy at the couplings
• minimum stress into the drilling rods
• better bit penetration

Energy Recovery Valve

This valve allow the piston rebound energy to be utilized for the next blow, giving a definite advantage to the HC series drifters:

• better efficiency
• no internal peak of pressure source of cavitation
• best drifter protection

Straight Holes Drilling

When associated with Montabert drilling automatics.

Hydraulic Reverse Percussion

The optional hydraulic reverse percussion system insure a real back hammering:

• tool extraction in fractured ground
• no rods left in the hole