Abstract: An improved power tong is provided of the type having a open throat portion for laterally moving the tong on and off a string of tubing. A ring member is rotatably guided by upper, lower, and intermediate bearings, and a cage plate assembly is partially disposed within the ring member. The rotatable cage plate is adapted for gripping engagement with a first string of tubing. An opening is provided between an outermost surface of the cage plate and ring assembly and an inner surface of a door for receiving a second string of tubing. According to the method of the invention, the first string of tubing is made up by rotating the ring member and cage plate assembly while the second string of tubing is housed within the body of the tong.

Abstract: A power tong includes a frame and a pipe-gripping mechanism associated with a throat at one end of the frame. Power is transmitted to the pipe-gripping mechanism from a power unit through a drive train. The pipe-gripping mechanism cooperates with the throat to receive a pipe section to be rotated and includes a partial ring rotatably mounted within the frame and having an opening which may be aligned with the throat. The ring may be rotated in either direction by the power unit. Mounted on the tong is a die carrier which is rotatable relative to the ring. Die members are mounted on the die carrier and include dies positioned to grip the external surface of the pipe section. The die members are arranged to cooperate with cam surfaces on the ring so that, when the ring is rotated relative to the die carrier, the dies are moved rectilinearly into engagement with the pipe section.

Abstract: A back-up tong for use with a power tong holds the lower pipe in a pipe joint from being rotated, so as to effect makeup or breakout of the pipe joint. The back-up tong employs sliding heads which are driven by camming surfaces on a ring-like member fixedly positioned about the pipe, when the heads are arcuately rotated about the pipe. The assembly holding the heads is arranged to be released automatically from the bottom of the back-up tong frame, in the event that the drill string begins to slip back down into the hole, or in the event a portion of the string is prematurely lifted, thereby preventing damage to the back-up tong. The back-up tong is constructed so that only a minimum amount of clearance is required at the top working surface, thereby permitting the sliding heads to be located as near the joint as possible when simultaneously using a power tong.

Abstract: A back-up tong for use with a power tong holds the lower pipe in a pipe joint from being rotated, so as to effect makeup or breakout of the pipe joint. The backup tong employs sliding heads which are driven by camming surfaces on a ring-like member fixedly positioned about the pipe, when the heads are arcuately rotated about the pipe. The assembly holding the heads is arranged to be released automatically from the bottom of the back-up tong frame, in the event that the drill string begins to slip back down into the hole, or in the event a portion of the string is prematurely lifted, thereby preventing damage to the back-up tong. The back-up tong is constructed so that only a minimum amount of clearance is required at the top working surface, thereby permitting the sliding heads to be located as near the joint as possible when simultaneously using a power tong.