Patent ID: 6431801
Filing Date: 2002-08-13
Classification: B23B,B27G,Y10T

Abstract:
In a drill bit for boring holes in a workpiece, said drill bit comprising:a generally elongate shank; and a head at a distal end of said shank, said head having a front portion, a rear portion and there-between a main body portion, said head comprising: a plurality of flutes, arranged in a generally helical manner along said main body portion and extending radially outwardly therefrom, each said flute having an outer cutting edge, to provide cutting capability in a direction substantially sideways compared to a longitudinal direction of said drill; a central point, arranged on said front portion of said head, said central point being connected to at least one of said plurality of flutes via a tapered front cutting portion, said front cutting portion having a front cutting edge, to provide cutting capability in a substantially forwards direction; a forward facing roughing part, arranged at an outer portion on at least one of said plurality of flutes, on said front portion of said head, said forward roughing part having a forward roughing edge, to provide further cutting capability in a substantially forwards direction; said rear portion of said head being connected to at least one of said plurality of flutes via a rear cutting portion, said rear cutting portion being provided with a rear cutting edge, to provide cutting capability in a substantially rearwards direction, said head having a rearward facing roughing part, arranged at an outer portion on at least one of said plurality of flutes, on said rear portion of said head, said rearward roughing part having a rearward roughing edge, to provide further cutting capability in a substantially rearwards direction.