Patent ID: 6588520
Filing Date: 2003-07-08
Classification: B23B,E21B,Y10T

Abstract:
A rock drill for abrasive working of rock or rock-like material where the drill movement at least partially rotates and impacts with respect to a drill axis (A), said rock drill having a drill head (1) with at least one hard material insert (2) secured to the drill head, said insert (2) has at least two hard material cutting edges (3, 7) extending radially outwardly from and spaced angularly apart relative to the drill axis (A), said cutting edges each having a radial extent outwardly from said drill axis, wherein at least two said cutting edges have recesses (4) extending axially inwardly for a part of the axial dimension of said hard material insert (2) from said cutting edges in the range of 20% to 50% of the radial extent thereof and with said recesses spaced radially apart at different radial dimensions relative to the drill axis whereby said cutting edges rotating around the drill axis form radially spaced apart continuous annular cutting surfaces and recesses.