摘要 |
A drilling apparatus including a hydraulically powered hammer having a piston to impact a drill bit; a shuttle valve to control reciprocation of the piston; and an accumulator for hydraulic fluid; at least one drill rod having a first connection valve for connection of the drill rod to the connection valve of the hammer; and a second connection valve for connection of the drill rod to the first connection valve of a like drill rod or to a rotation device. The piston and shuttle valve are positioned substantially in-line to the axis of movement of the hammer. The accumulator is positioned proximate to the shuttle valve; and the first connection valve, and second connection valve having at least one poppet valve positioned proximate to a corresponding valve seat. |