| 摘要 |
<p>In a rotary blast hole drill, three drill pipes are stored in the drill mast for use in extending the length of the drill stem. Each of the drill pipes is stored in a rack that has a socket in the bottom to receive the bottom end of the pipe and a pair of jaws articulating about a common pivot to restrain the top end of the pipe. The jaws are locked in a closed position with a lock operated by a pneumatic motor, which is controlled by a valve that is actuated when a pipe is removed from or inserted in the socket. The pipe rack in its storage position is held by a pneumatically operated latch that is interlocked with the rack operator.</p> |
