ROTATABLE DIE HOLDER

摘要

A jaw assembly is provided for a power tong or back-up tong to make up and break out a pipe section. The jaw assembly includes a jaw element for transferring torque from the tong to the pipe section, and a means for moving the jaw element into and out of gripping engagement with the pipe section. At least one die holder is rotatably mounted to the jaw element and is adapted to freely twist about a first axis oriented generally parallel to a longitudinal axis of the pipe section when engaged with said jaw element. The rotation of the die holder about the first axis allows the die holder to align itself with the pipe section upon engagement therewith and to provide an independent camming action against the pipe section to at least radially maintain the die holder's grip on the pipe section and avoid slippage therebetween when transferring torque. The jaw assembly may therefore be used on a range of pipe sizes without having to change the jaw.