Patent ID: 6116361
Filing Date: 2000-09-12
Classification: E21B

Abstract:
A drill, comprising a shank (1) for connecting the drill with a drive tool; a stem (2) adjoining the shank (1) and having two helical discharge grooves (6, 7) opening toward a stem circumference; and a head (3) provided at an end of the stem (2) remote from the shank (1) and having a diameter substantially corresponding to the stem diameter, the head (3) having three radially extending recesses (8) provided in a free end surface thereof and opening toward a head circumference, the recesses (8) being provided with at least one hard metal bit (9) provided with cutting portions (9a) extending from a central portion (9b) to the circumference of the head (3), the head (3) having three grooves (10, 11, 12) arranged between the three recesses (8), opening toward the head circumference, and connected with the discharge grooves.