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: An open throat power tong 10 as commonly used for making up and/or breaking apart an oilfield tubular connection, comprising a tong body 20, a tong door assembly 40, a partial ring member 30 and a ring segment 150. The partial ring member 30 and ring segment 150 may not be structurally connected and each may support one or more jaw members thereon for gripping a tubular 11. The partial ring member 30 and ring segment 150 may rotate substantially in unison along a substantially common plane and about a common axis, along a defined rotation course through the tong body 20 and door 40. The ring segment 150 may be substantially secured within the door when the door 40 is opened. An improved latch mechanism 100 is included for securing the door 40 to the tong body 20 to facilitate relatively easy closing and latching and unlatching of the door 40 with the tong body 20, and to prevent expansion of the open throat 25 during application of high torque.

Abstract: An open throat power tong 10 for making up and/or breaking apart an oilfield tubular connection includes an open throat in the tong body 15. Motors 18, 20 rotate a partial ring member 12 and a pair of heads 16 with respect to the tong body. A door 40, 140 may be opened to expose the open throat of the power tong, and has a planar latch surface formed from arcuate groove 58 for receiving an arcuate boss 90. The door latch mechanism reduces the effort required to safely latch the door in the closed position before operating the tong, and provides a highly reliable mechanism to minimize spreading of the tong body under a relatively high torque.

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: 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: An improved open throat power tong assembly is provided of the type useful for making up and breaking apart threaded pipe joints. The power tong assembly includes a cage plate assembly with a plurality of pipe gripping heads and a partial ring having a plurality of internal cam surfaces. The heads are forced into gripping engagement with the pipe by relative rotational movement between the cam surfaces and the heads mounted in the cage plate assembly. The cage plate assembly may be both supported by and rotationally guided by a plurality of ball bearing assemblies mounted to the cage plate assembly. The bearing balls are biased into engagement with an arc-shaped groove provided in the upper and lower surfaces of the partial ring. During operation of the tong, the ball bearing assemblies ride in the deepest depression track of the groove, but may purposefully ride up the groove sidewall during the final make-up and initial break-out operation.