| 摘要 |
A rock drill bit for percussive drilling includes a front face which has radially outer and inner portions. Fluid channels are disposed in the head portion in communication with the inner portion of the front face. The inner portion of the front face carries a plurality of front buttons. The outer portion comprises circumferentially spaced steel portions which are axially raised relative to the inner portion. Each raised portion carries one or two peripheral buttons located radially outwardly of an imaginary circle which intersects at least two of the front buttons and at least two of the flushing channels. The imaginary circle is arranged coaxially relative to the center axis. |
