| 摘要 |
A device for reducing the break-out torque in a drill pipe tool joint selectively can be disabled so that break-out is at standard torque. The torque reducing device includes a collar located on the pin. The collar has a makeup shoulder that makes up against the makeup shoulder of the box of the drill pipe. The collar has a pair of ramp rings that will slide relative to each other during break-out torque. When they slide, they reduce the overall vertical height, allowing the collar to move vertically from the makeup shoulder a slight distance to reduce the torque. A split ring encircles the ramp rings for urging the ramp rings back to the initial position. A pin engages a slot in the split ring. The pin can be rotated between locked and unlocked positions to prevent the split ring from expanding. This prevents the ramp rings from operating.
|
