| 摘要 |
<p>An improved slip-type elevator locking mechanism has a lock rod which has one end connected to the slipsetting yoke and a free end extending generally parallel with the direction of movement of the slips in the elevator bowl. A cam arm mounted on the elevator at a central pivot point has a cam throat on one end which is adapted to receive the lock rod free end and an opposite end and is pivotable about the central pivot point between upper and lower lock rod engaging positions and a neutral, unlocked position. A fluid cylinder is pivotally mounted by a base end to the elevator and is pivotally attached at its output shaft to the cam arm opposite end for urging the cam arm to the neutral position. The fluid cylinder output shaft is spring-biased outwardly away from the base end in the absence of fluid pressure on the cylinder. A yoke rod has one end connected to the slip-setting yoke and a free end extending in a direction generally parallel to the lock rod in a plane which intersects the plane of the cam arm opposite end. Upper and lower coil springs on the yoke rod urge the cam arm toward a select one of the upper and lower lock rod engaging positions when fluid pressure is lost.</p> |
