| 摘要 |
PCT No. PCT/GB88/00555 Sec. 371 Date Feb. 21, 1990 Sec. 102(e) Date Feb. 21, 1990 PCT Filed Jul. 8, 1988 PCT Pub. No. WO89/00236 PCT Pub. Date Jan. 12, 1989.A mining machine having a boom and a rotary cutting head has water jets directed to the picks of the head and apparatus to phase water supply to only those picks engaging the face to be cut. The water supply system includes circumferentially disposed chambers in the cutting head, each to direct at least one jet to one or more picks and each having a valves to control entry of water thereinto. A drive swash plate which is in surface contact with valves in the chambers is adapted in use to be stationary relative to the cutting head for actuating the valves moving into the cutting area. Water is fed to the chambers by a rotatable lance on which the drive swash plate is fixedly mounted. A break swash plate is also mounted on the lance for engagement with a brake adapted to stop rotation of the lance, such that the drive swash plate is in a selected stationary disposition to actuate the appropriate valves moving into the selected cutting area. The brake is selectively controlled by movement of the cutting boom.
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