Abstract: A rock drill bit having a shank fitted with a clamping end and a drilling tip located from the clamping end. The drilling tip has at least three blades and a central zone centered on a drill bit axis. The blades each include on a top side thereof a lip constituted by a leading chipping face and a trailing flank. The lips substantially converge onto each other within a the central zone of the drilling tip, wherein in the central zone, a long lip of the lips runs through the drill bit axis and has a commensurate overshoot segment extending beyond the drill bit axis.
Type:
Grant
Filed:
September 3, 2009
Date of Patent:
February 24, 2015
Assignee:
Heller Tools GmbH
Inventors:
Heinrich Kersten, Joerg Frommeyer, Sven Elmers, Hermann Albers, Ranier Lampe