| 摘要 |
<p>A mining machine having a boom (2) and a rotary cutting head (1) has water jets directed to the picks of the head and means to phase water supply to only those picks engaging the face to be cut. Water means supply include circumferentially disposed chambers (14) in head (1) each to direct at least one jet to one or more picks and each having valves (15) to control entry of water thereinto. A drive swash plate (17) which is in surface contact with valves (15) of chambers (14) is adapted in use to be stationary relative to head (1) for actuating these valves (15) moving into the cutting area. Water is fed to chambers (14) by a rotatable lance (20) on which drive swash plate (17) is fixedly mounted. A brake swash plate (18) is also mounted on lance (10) for engagement with brake (9) adapted to stop rotation of lance (10) such that drive swash plate (17) is in a selected stationary disposition to actuate the appropriate valves (15) moving into the selected cutting area. Brake (9) is selectively controlled by movement of cutting boom (2).</p> |
