Cam arm actuated backup tong

摘要

A backup tong that comprises an activating mechanism for advancing a jaw die mounted on a jaw carrier within the backup into engagement with a pipe positioned centrally therein. The jaw carrier is fitted within the tong body to permit a sliding action radially toward the center point of the opening in the backup tong. Such mechanism includes a cam surface located along a first extension of a cam arm which pivots around a fixed pivot pin carried by the body of the backup. The other extension of the cam arm is connected toward its outer end to an actuator, anchored at one end to the backup body and oriented at the other end to swing the cam arm about the pivot pin.