| 摘要 |
A percussive rock drill bit having a head 100 comprising an annular gauge collar 101 and a central island 104. An annular cutting channel is defined between the collar 101 and the island 104 such that specifically positioned cutting buttons 112,115 are effective to create an annular ridge in the cut rock face having a reduced rock breaking resistance to increase the rate of drilling and/or decrease the required power consumption. |
