摘要 |
<p>A drill bit (21, 121) for rock drilling tools includes a drill bit head (23, 123) having a front surface (27, 127) including a face surface (29, 129) defining a forward-most end of the drill bit head (23, 123). The face surface (29, 129) has an outer edge (31, 131), a gauge (35, 135) surrounding the face surface (29, 129), the gauge (35, 135) having an inner edge (37, 137), and a transition region (38, 138) that extends in a direction of a longitudinal axis (L) of the drill bit (21, 121) between the outer edge (31, 131) of the face surface (29, 129) and the inner edge (37, 137) of the gauge (35, 135). An entirety of the face surface (29, 129) from which the cutting surfaces are adapted to extend is non-flat so that a center (33, 133) of the face surface (29, 129) is axially forward of the outer edge (31, 131) of the face surface (29, 129). The gauge (135) can include a first gauge surface (135') defining a first angle with the longitudinal axis (L) over a first portion of a circumference of the gauge (35, 135) and a second gauge surface (135") defining a second angle with the longitudinal axis (L) over a second portion of the circumference of the gauge (35, 135).</p> |