| 摘要 |
<p>A device for automatically controlling drilling rig prime mover power transmission to the rotary table upon sensing of an excessive torque encountered by the drill string. The device consists of a plurality of valves interconnected in bypass of normal neutral brake and master clutch activation mechanism which can be energized to assume full automatic command of the rotary table and drive thereto such that sensing of excessive torque actuates the safety valve device to energize the neutral brake and de-energize the master clutch supplying rotary drive power to the rotary table. Thereafter, lessening of the excessive torque will automatically enable reactivation of the master clutch and neutral brake to resume application of drive power to the rotary table.</p> |
