Fluid operated undercutter

摘要

An undercutter comprising a slotted tubular body in which is mounted an extendable and retractable cutting head for undercutting a bore into which the tubular body is positioned and rotated. The cutting head includes a fluid-operated reciprocally movable piston, the reciprocating rate of which is determined by an annular liner positioned between the outer wall of the piston body and the inner wall of the piston cavity.