| 摘要 |
A power tong having a frame with an open throat at one end and a pipe gripping mechanism situated for rotation within the frame, carrying three pipe gripping dies about equally spaced around the longitudinal axis of the pipe. Only one of the pipe gripping dies is driven toward the pipe by cam action of the rotating mechanism. The other two pipe gripping dies pivot and achieve their pipe loading capability from the action of the cam driven pipe gripping die. Once the rotation of the pipe has been achieved, the rotating mechanism returns to such a position that the open throat of the rotating mechanism coincides with the open throat of the frame, whereby the pipe, having been spun, can then be released.
|
