Abstract: A frame stiffener for a power tong frame comprises a body having a top surface securable to a top plate of the frame, a bottom surface securable to the bottom plate of the frame, an outer side and an interior side having a plurality of recesses, each recess formed to conform to an angular portion of an adjacent dumbbell roller secured within the frame along with a plurality of other dumbbell rollers to rollably surround, engage and stabilize a ring gear rotatably disposed within the frame.

Abstract: A latch mechanism for securing a pivoting door of a power tong in a closed position across a lateral opening to an interior bay of the power tong includes a door cylinder coupled at a proximal end to the body and having an extendable rod to pivot the door between a closed position, across the lateral opening, and an open position providing lateral access to the interior bay, the power tong further includes a latch cylinder coupled at a proximal end to the door and having an extendable rod to pivot a latch member to pivot between an engaged position, to engage a latch post on the body, and a retracted position to disengage the latch post of the body.

Abstract: A power tong 10 rotates a tubular during makeup or breakout of the threaded connection. A tong frame 12, a rotatable ring 20, and a cage plate assembly may each have an open throat for receiving the tubular. A plurality of dies 32 are preferentially manufactured from aluminum, and each have a knurled surface for engaging the tubular. A fluid powered cylinder 54 increases tension between the brake band 50 and the cage plate assembly. Neutral cam portions of the cam surface one positioned radially outward substantially from the makeup and breakout cam portions.

Abstract: A tong positioning system positions a power tong about an oilfield tubular connection to make up or break out a threaded connection. An extendable arm and a retainer device on the extendable arm. In a preferred embodiment, the retainer device comprises opposing laterally-movable retainer arms defining an adjustable opening for at least partially enclosing one of the upper tubular and the lower tubular. The extendable arm is retractable for thereafter moving the power tong laterally toward the tubular connection.

Abstract: A backup tong 10 secures the tubular against axial rotation in response to rotation by a power tong. The backup tong plate 20 supports a pair fluid powered cylinders 32, 34, and a pair of swing arms 50, 52 each pivotally connected to the respective fluid powered cylinder. A left side cam plate 44 and a right side cam plate 46 are each provided for cooperation with a respective left side and right side cam follower 58, 60. The gripping head 30 provided on the backup tong plate, and a pair of gripping heads 62, 64 are provided on a forward end of each of the swing arms for gripping the tubular. A method of the invention includes supporting the fluid powered cylinders on the backup tong plate, and pivotally connecting the swing arms to the respective fluid powered cylinders. The cam followers move within respective cam plates during actuation of the cylinders.

Abstract: Power tongs are described for making up and breaking apart joints of pipe. The hydraulic system of the tong comprises a tandem fluid motor which enables both forward and reverse operation of the tong in one of several selected speed/torque ranges by operating a pair of control handles. The open throat tong includes a door latching mechanism for automatically locking and unlocking the tong door when activating the tong hydraulic system. The tong dies come into gripping engagement with the pipe over a large composite arcuate angle to increase the pipe gripping ability of the tong.

Abstract: A powered back-up assembly is provided for securing a pipe against rotation. A plurality of heads are supported by a cage plate assembly, and are brought into gripping engagement with the pipe by rotating the cage plate assembly relative to a cam ring fixed to the body of the tong body. The cage plate assembly is rotated by a pair of hydraulic cylinders each connected at one end to a bar pivotably connected to the tong body. A third hydraulic cylinder interconnected between adjacent upper and lower tong bodies may be employed to achieve a reliable scissors tong, whereby the body of the upper tong is rotatable relative to the body of the lower 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 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 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. Link members are pivotally mounted on the die carrier and include dies positioned to grip the external surface of the pipe section. The link members are arranged to cooperate with specially designed cam surfaces on the ring so that, when the ring is rotated relative to the die carrier, the dies are moved into engagement with the pipe section.