Power tong gripping ring mechanism

摘要

A multi-sectioned, bidirectional gripping ring for a closed-head power tong is disclosed of the inventive gripping ring have an open position in which a pipe may be placed within or removed from the gripping ring and a closed position in which the gripping ring completely encircles the pipe. The inventive gripping ring uses radially moveable dies in circumferentially moveable die carriers to grip the pipe. The dies are synchronously moved in the radial direction to grip or release the pipe by changing their circumferential position with respect to the cams in the gripping ring housing.