FORCE PULSE SHAPING MEMBER FOR PERCUSSION TOOL

摘要

A member comprising the shank or an integral shank-drill rod for a percussion rock drill and having a force-deflection or stiffness characteristic similar to the effective stiffness of the earth formation to be penetrated. The member is adapted to be removably inserted into the rock drill in blow-receiving relationship with a reciprocating hammer element. The member is also operable to be a rotation transmitting means for rotating an extension drill string.