Patent ID: 6032749
Filing Date: 2000-03-07
Classification: B23B,E21B

Abstract:
A drilling tool for use in a drilling device for drilling into a hard receiving material, such as for drilling masonry, concrete, rock and similar hard receiving materials and comprising an axially extending shank (1) having an axis and arranged for insertion into a chuck of a drilling device, said shank (1) having a first end and a second end spaced apart in the axial direction, an axially extending shaft (2) having an axis arranged in alignment with the axis of said shank (1) and having a first end secured to the second end of said shank and a second end, said shaft (2) having two spaced helical grooves (5, 6) in an outside surface thereof and extending between said first end and second end of said shaft, a drill head (8) having a diameter (D1) located at the second end of said shaft (2), and a cutting plate (7) inserted in said drill head (8) and projecting axially outwardly from said drill head (8), said cutting plate (7) having a pair of opposite ends each located outwardly from a circumferentially extending outside surface of said drill head and a pair of opposite sides extending between said pair of ends, said cutting plate (7) having a cutting tip (74) arranged approximately on the axis of said shaft with said cutting tip (74) located axially outwardly from said drill head, said cutting plate (7) having a dimension (B) between said pair of opposite ends and extending perpendicularly of the axis of said shaft (2) and said dimension (B) being appreciably greater than the diameter (D1) of said drill head (8) and projecting outwardly from the circumferentially extending outside surface of said drill head, said helical grooves (5, 6) having ends in said drill head (8) terminating at diametrically opposite sides on the circumferentially extending outside surface of said drill head and on opposite sides of said cutting plate and said helical groove ends extending generally parallel to the axis of said shaft (2) and co-extending axially with at least an axially extending part of said cutting plate spaced from said cutting tip, said cutting plate (7) having a reinforcing section (71) on each of said opposite sides of said cutting plate and spaced in the circumferential direction of said drill head from said helical groove ends, and second reinforcing sections located on diametrically opposite sides of the axis of said shaft (2), and said cutting plate (7) is secured in a recess (11) of said drill head with said recess (11) arranged between said helical groove ends in the region of said cutting plate.