Abstract: A power tong assembly for making and breaking a tubular connection may include a first tong operable to engage a first tubular and a second tong operable to engage and rotate a second tubular relative to the first tubular to make or break the tubular connection. The second tong may include a rotation lever operable to set rotation of the second tong to a makeup setting or a break out setting and a speed lever operable to set rotation speed of the second tong in a low speed position or a high speed position. A system for selectively preventing high speed rotation of the power tong comprising a rotation lever position locking element and a coupling mechanism. The rotation lever position locking element may be movable between a blocking position and a non-blocking position. The coupling mechanism may couple the rotation lever position locking element to the speed lever.

Abstract: A rotor carries a gripping mechanism operable to grip an elongated object such as a drill string section. The rotor is driven by one or more drive mechanisms comprising a flexible element such as a chain. The flexible element allows some relative motion of the rotor and the drive mechanism. The described apparatus has application in making and breaking connections between tubulars in subsurface drilling operations.

Abstract: A power tong is provided for rotating a pipe, the power tong comprising: a frame having a pair of arcuate front portions defining a throat for receiving the pipe; a ring gear mounted for rotation on the arcuate front portions about a center of rotation, the ring gear having an opening that is alignable with the throat; and a cage plate assembly mounted for rotation on the ring gear on a bearing arrangement that includes roller bearings and a bushing sliding segment on each side of the throat. Taking the throat as having a center line that defines a zero circumferential position within the power tong, the bearing sliding segments may be located within 90 degrees of the throat center line.

Abstract: A portable bucking frame for making and breaking tubular connections includes a base, a pair of back-up jaws movably mounted to the base for receiving a pipe and an adapter plate mounted on the front end of the base. The adapter plate is configured to receive one of a plurality of power tongs for making or breaking pipe connections.

Abstract: A pipe wrench for making-up or breaking-out a threaded connection between a first tubular member and a second tubular member includes an upper wrench assembly with a pair of upper jaw assemblies configured to grip the first tubular member and a lower wrench assembly with a pair of lower jaw assemblies configured to grip the second tubular member. The upper and lower wrench assemblies are concentrically constrained, axially overlap, and radially engage with one another. Each of the upper and lower wrench assemblies independently includes a frame with a curved segment containing an arc at an angle of about 160° to about 200°. The upper and lower wrench assemblies are configured to rotate the first tubular member relative to the second tubular member and can have an angle of rotation in a range from about 75° to about 180°.

Abstract: One or more specific versions disclosed herein includes a power tong for rotating tubulars in wellbore operations, comprising: a gear shaft having a non-threaded portion and a flange; a gear rotatably connected to the gear shaft; and a tong plate having an inner surface and an outer surface, wherein the flange is removably coupled to the inner surface of the tong plate.

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: One or more specific versions disclosed herein includes a power tong for rotating tubulars in wellbore operations comprising: a gear shaft having a non-threaded portion; a gear rotatably connected to the non-threaded portion of the gear shaft; a tong plate having an inner surface, an outer surface, and a gear shaft aperture, wherein an end of the non-threaded portion is disposed in the gear shaft aperture; and a shaft retainer that is removably coupled to the tong plate and abutted against the end of the non-threaded portion.

Abstract: A well lift frame, clamp assembly therefor, and method for handling well equipment is disclosed. In an embodiment, the lift frame includes a frame, a vertical slot forming an opening in a side of the frame, and a clamping assembly mounted to the side of the frame near the opening. The clamping assembly may include a linkage assembly arranged so as to travel along an arcuate path between a disengaged position, in which the clamping assembly is substantially clear of the opening, and an engaged position in which the clamping assembly at least substantially covers a horizontal extent of the opening. The linkage assembly may define a four-bar linkage mechanism. The clamping assembly may also include an actuator coupled to the linkage assembly so as to selectively position the linkage assembly, and a shoe carried by the linkage assembly for contacting and clamping equipment within the vertical slot.

Abstract: Examples disclosed herein relate to one or more wrench devices. An apparatus may include a drive gear assembly configured to be coupled to a power source. The drive gear assembly may include a plurality of drive gears. The apparatus may include a cam assembly coupled to the drive gear assembly. The cam assembly may include a first cam and a second cam. Further, the first cam and the second cam may be configured to interact with each other to move a part.

Abstract: An automated, electric tong system and methods usable for making-up and breaking out threaded connections between tubular members, wherein the electric tong system comprises a power tong for applying torque and rotating the upper tubular member, a backup tong for gripping tubulars, and a lift assembly for vertically moving the electric tong system into proper position to grip the upper and lower tubulars. The power and backup tongs and lift assembly of the electric tong system are integrated into a single transportable unit and operated by three separate electrical motors, controlled by a single driver. The backup tong is located below the power tong and comprises a pneumatic cylinder, which operates a backup door, and a linear actuator driven by an electric motor for use in latching the backup tong door in a closed position and applying or releasing a clamping force to a tubular, during make-up or break-out operations.

Abstract: A clamping system for making and breaking threaded connections between a first tubular and a second tubular comprises a clamp assembly. The clamp assembly includes a first cam gear, a first plurality of clamp members disposed within the first cam gear, and a torque gear. Each clamp member is pivotally coupled to the torque gear. Each clamp member is configured to pivot between a withdraw position radially spaced apart from the first tubular and a gripping position engaging the first tubular. In addition, the clamping system comprises a clamp actuator. The clamp actuator includes a mounting shaft, a first clamp drive gear rotatably coupled to the mounting shaft, and a torque drive gear rotatably coupled to the mounting shaft. The first clamp drive gear is configured to rotate the first cam gear and the torque drive gear is configured to rotate the torque gear.

Abstract: The invention relates to a pipe clamping device comprising a housing which has a tubular center in which a pipe is to be positioned. The pipe clamping device comprises at least three gripping devices for synchronous movement in towards the pipe. Each gripping device is disposed with a direction of movement in towards the tubular center, where each gripping device is arranged in order, in contact with the pipe, to provide a holding force. The pipe clamping device is provided with elongate flexible transmission elements, each of the elongate flexible transmission elements being attached to one of the gripping devices and running in contact with at least one support means to attachment to each of the other gripping devices. Upon movement of at least one of the gripping device, this movement is transmitted to at least one of the other gripping device by the associated elongate transmission element.

Abstract: A wrench for unthreading a well head flange from a pipe is provided. The wrench can include a pipe jaw for gripping the pipe, and a torque arm assembly for applying rotational force to the well head flange. The assembly can include a torque arm wherein one end of the torque arm can be pivotally attached to a bolt hole disposed through the well head flange. Extending a cylinder disposed between the assembly and to an opposing end of the torque arm can cause the torque arm contact and rotate the well head flange relative to the pipe.

Abstract: A bearing is for a tong including a housing and an engagement assembly. The bearing has a monolithic upper bearing element having a substantially planar upper surface and a monolithic lower bearing element having a substantially planar lower surface. The upper and lower bearing elements are configured to mount inside the housing with a substantially same outer horizontal profile as the upper bearing element. The upper bearing element and the lower bearing element define a central open area. The upper bearing element and the lower bearing element have an inner section defining a radial recess opening to the central opening and for receiving the engagement assembly. The upper bearing element and the lower bearing element have outer sections that form a bearing portion radially intermediate the engagement assembly.

Abstract: A power tong for rotating a pipe, the power tong comprising: a frame having a pair of arcuate front portions defining a throat for receiving the pipe; a cage plate assembly mounted for rotation on the arcuate front portions about a center of rotation, the cage plate assembly having an opening that is alignable with the throat; a ring gear mounted for rotation within, and supported by, the cage plate assembly about the center of rotation, the ring gear having an opening that is alignable with the throat; the ring gear cooperating with jaws mounted on the cage plate assembly for gripping the pipe upon rotation of the ring gear.

Abstract: An apparatus for removing a nut is described. The apparatus includes a housing, a cage, and a canted coil spring. The housing has a top surface, an interior sidewall, and a bottom surface. The interior sidewall defines an orifice that extends from the top surface to a lip. The interior sidewall includes a three-lobed cam and a groove. Each lobe has a lobe center line, a counterclockwise cam inner surface on one side of the lobe center line, and a clockwise cam inner surface on the opposite side of the lobe center line. The canted coil spring is received by the groove of the interior sidewall and the groove of the cage. The canted coil spring rotatably couples the cage to the housing. During nut removal, the housing rotates counterclockwise relative to the cage. The cage rotates counterclockwise to engage the nut, and the cage interfaces with the interior sidewall.

Abstract: A hydraulic puller device for pulling bearings, gears, wheels and pulleys from objects such as shafts and axles and other machine parts. The hydraulic puller device includes a mobile base assembly, a jaw assembly being mounted to the base assembly and including a plurality of jaw members, a press assembly being mounted to the base assembly for urging against an object to facilitate the removal of a press fitted work piece, and a control assembly being in fluid communication with the base assembly, the jaw assembly and the ram assembly.

Abstract: A clamping system for making and breaking threaded connections between a first tubular and a second tubular comprises a clamp assembly. The clamp assembly includes a first cam gear, a first plurality of clamp members disposed within the first cam gear, and a torque gear. Each clamp member is pivotally coupled to the torque gear. Each clamp member is configured to pivot between a withdraw position radially spaced apart from the first tubular and a gripping position engaging the first tubular. In addition, the clamping system comprises a clamp actuator. The clamp actuator includes a mounting shaft, a first clamp drive gear rotatably coupled to the mounting shaft, and a torque drive gear rotatably coupled to the mounting shaft. The first clamp drive gear is configured to rotate the first cam gear and the torque drive gear is configured to rotate the torque gear.

Abstract: A clamp includes a first cam assembly including a hollow first support, opposite first and second work piece clamping members partially disposed in the first support with a first slot defined therebetween, a bifurcated first cam lever on both sides of the first and second work piece clamping members with the first support in the first cam lever, and an annular first flange including a latching groove; a second cam assembly including a hollow second support, opposite third and fourth work piece clamping members partially disposed in the second support with a second slot defined therebetween, a bifurcated second cam lever on both sides of the third and fourth work piece clamping members with the second support in the second cam lever, and an annular second flange including an end reduction, a projection distal the reduction, and external threads; and a fastening member threadedly secured to the second flange.

Abstract: An attachment is described that is configured for attachment to an arm of a piece of heavy construction equipment. The attachment is configured to rotate a section of pipe during break out (i.e. disconnection or disassembly) from another section of pipe and/or make up (i.e. connection or assembly) with another section of pipe. The attachment is configured to break the joint or torque the joint to a predetermined torque value, unthread or thread pipe, and lift the pipe under the power of the heavy construction equipment.

Abstract: A power tong jaw comprising a jaw body having upper and lower flange sections with flange apertures formed through the upper and lower flange sections. The power tong jaw will further have a jaw roller including a pin aperture and a roller pin positioned through the pin aperture in the jaw roller and through at least one of the upper or lower jaw flange apertures. The power tong jaw will further include a flexible retaining mechanism (i) positioned between outer surfaces of the upper and lower flange and (ii) engaging the roller pin.

Abstract: A prior art sucker rod tong is improved to remove a coupling completely from a sucker rod assembly comprising sucker rods joined end to end by couplings. The prior art sucker rod tong has a rotatable jaw assembly and a lower backup wrench adapted to cooperate to unscrew a coupling joining first and second rods, where the coupling remains screwed to the second rod after it is unscrewed from the first rod. The improvement comprises a coupling extractor for unscrewing the coupling from the second rod so that the coupling can be replaced. The coupling extractor comprises a shaft having an extractor end portion on each end of the shaft and a shield around each extractor end portion, wherein the coupling extractor is designed and sized to fit within and to be rotated by the jaw assembly. The extractor end portion engages the inside wall of the coupling to unscrew the coupling from the second rod. The extractor end portion is preferably a tapered, left-handed spiral fluted easy-out extractor.

Abstract: A power tong body having a central opening comprises upper and lower cover plates and a rotary gear contained there between. The tong incorporates the centering guide, e.g. rollers, that extend between the rotary gear and respective tong covers. Such centering guides through the central openings in the tong body covers and provide contact surfaces carried that permit differential rotation of the rotary gear with respect to such covers. The rollers may roll on circular races formed by the inside edge face surfaces of the tong covers bordering the central opening. The support rollers may also extend beyond the upper and lower cover plates and engage with a guide surface or race formed on the respective cage plates of the tong, centrally locating such cage plates with respect to the rotary gear while allowing differential rotation of the cage plates with respect to the rotary gear.

Abstract: A rod tong assembly has inner and outer rings. The outer ring has rollers disposed about a central opening. The inner ring disposes in the outer ring and has three jaws for engaging a rod element. The outer ring is rotated clockwise to make a rod connection and is rotated counter-clockwise to break the rod connection. When rotated, the rollers pivot the opposing jaws pivot against flats of the rod element. Further rotation of the outer ring then rotates the inner ring to respectively tighten or loosen the connection. To return the assembly to its default condition, operators switch a lock disposed on the inner ring to a return condition. When the outer ring is then rotated back, the lock catches on the outer ring and allows the inner ring to rotate in the same direction as the outer ring.

Abstract: A power tong jaw comprising a jaw body having upper and lower flange sections with flange apertures formed through the upper and lower flange sections. The power tong jaw will further have a jaw roller including a pin aperture and a roller pin positioned through the pin aperture in the jaw roller and through at least one of the upper or lower jaw flange apertures. The power tong jaw will further include a flexible retaining mechanism (i) positioned between outer surfaces of the upper and lower flange and (ii) engaging the roller pin.

Abstract: Apparatus and methods for rotating or spinning a tubular. In some embodiments, the apparatus, referred to herein as a pipe spinner, includes a body, an arm pivotally coupled to the body, and an actuator coupled to the arm. The arm has a cam roller coupled thereto. The actuator is operable to pivot the arm relative to the body between an open position and a closed position. In the closed position, the cam roller engages the tubular. In the open position, the cam roller is disengaged from the tubular.

Abstract: A clamping mechanism includes a pair of contact portions facing each other which is capable of directly contacting a tie rod hexagonal portion, and an open-close drive mechanism that causes the both contact portions to move away from and approach the tie rod hexagonal portion. By appropriately changing the distance between surfaces of the mutually facing pair of contact portions, the tie rod hexagonal portion will be securely clamped by the pair of contact portions, regardless of the size of the diameter of the tie rod. Then, the tie rod hexagonal portion is rotated to adjust the toe angle, by rotating the clamping mechanism via the rotation drive mechanism.

Abstract: A method for gripping a tubular with a tubular gripping mechanism includes the steps of moving the tubular gripping mechanism adjacent the tubular, positioning a jaw assembly of the tubular gripping mechanism around the tubular, applying a force by an actuator onto the jaw assembly of the tubular gripping mechanism such that the jaw assembly moves so as to clamp onto the tubular, removing the force from the actuator onto the jaw assembly such that the jaw assembly remains clamped onto the tubular. The clamping force is directed to surfaces of the tubular gripping mechanism away from the actuator.

Abstract: An open-faced rod-spinning device configured for making and/or breaking joints between threaded drill rods. The rod-spinning device may include a drive gear with an open face. The drive gear may also be coupled to a plurality of drive pins. The rod-spinning device may include a carriage assembly including an open face for receiving and rotating about a drill rod. The carriage assembly may include a plurality of gripping lobes configured to be engaged and rotated by the drive pins about pivot pins. The drive gear may be configured to rotate relative to the carriage assembly to cause the drive pins to engage and rotate the gripping lobes.

Abstract: A gripping apparatus and a method apparatus for making up and breaking out tubular connections. In one embodiment, the gripping apparatus comprises an outer gear, a plurality of rollers coupled to the outer gear, an inner ring, a passive jaw, and a pair of active jaws pivotably coupled to the inner ring. The active jaws include camming surfaces for positioning, securing, actuating, and retracting the active jaws upon rotation of the outer gear. The gripping apparatus may further include a control switch operable to maintain the gripping apparatus in a make up mode or a break out mode regardless of rotation of the outer gear.

Abstract: An open-throat power tong for making up or breaking apart an oilfield tubular connection, includes a cage plate lock system. The lock system connected to each cage plate extends across the space provided by the open throat in the cage plate when locked in the closed position. This provides support for the cage plates, resisting their tendency for expansion. The cage plates are mounted on the ring gear for rotation about a common center. The support provided to the cage plates for resisting expansion is communicated to the ring gear, thus providing support to the ring gear against expansion.

Abstract: A power tong system for precisely making up a connection between two elongated elements, such as sucker rods, into an operative string for petroleum well installations. High precision is attainable to secure the full advantages of prestressing the coupling by combinatorial use of both a rotary drive to achieve a first contact position and a linear drive to secure a precise final torsioning. The mechanism for achieving this may employ a peripherally driven drive ring coupling gears engaged to the drive ring periphery, a rotatably driven drive and a linear gear rack which are both engageable to the coupling gear.

Abstract: A method and apparatus for handling tubulars is provided. In one aspect, the present invention provides a spinner having a first arm having a first roller and a second arm having a second roller, the first arm and the second arm simultaneously adjustable to retain the tubular. The apparatus also includes a third roller capable of urging the tubular against the first and second rollers, wherein at least one of the first, second, and third rollers is actuatable to rotate the tubular. In one embodiment, the spinner further comprises a fluid operated cylinder for adjusting the first arm and the second arm. The arms are adjusted by actuating the cylinder extend or retract the first arm and the second arm.

Abstract: A method of using a power tong (2) for use in the pipe make-up and pipe break-out of pipe lengths (22) during drilling in the ground as it is known from, for example, the recovery of petroleum, the power tong (2) being part of an assembly (1) which includes a back-up tong (4) movable relative to the power tong (2) in the longitudinal direction of the pipe length (22), and at least one guide column (10). The tong is releasably connected to a chassis and is arranged to be lifted up from a drill floor to a level higher up in order to break out a pipe from a pipe string, should the pipe string get stuck in the borehole.

Abstract: A gripping apparatus and a method apparatus for making up and breaking out tubular connections. In one embodiment, the gripping apparatus comprises an outer gear, a plurality of rollers coupled to the outer gear, an inner ring, a passive jaw, and a pair of active jaws pivotably coupled to the inner ring. The active jaws include camming surfaces for positioning, securing, actuating, and retracting the active jaws upon rotation of the outer gear. The gripping apparatus may further include a control switch operable to maintain the gripping apparatus in a make up mode or a break out mode regardless of rotation of the outer gear.

Abstract: The apparatus of the present invention is directed to a replacement cage assembly (106) to modify a conventional power tong (100) to enable the power tong to grip and rotate smaller diameter tubular segments (90). The method of the invention is directed to modifying a power tong (100) to grip and rotate a tubular segment of a diameter smaller than could be gripped by the unmodified power tong (100). The invention provides a rotary gear insert (240), having an interior second cam surface, rotatably captured intermediate an upper cage plate (230) and a lower cage plate (210) and slidably receivable within the conventional rotary gear of the power tong (100) and to cam and rotate a plurality of replacement gripping jaws (220, 221) pivotally captured adjacent the second cam surface (240) and intermediate the upper cage plate (230) and the lower cage plate (210).

Abstract: A jaw assembly, namely a multi-jaw assembly (preferably three-jaw) for a tong unit. The jaw assembly has a rear jaw connected to two side jaws, by pivot pins, to form a multi-jaw jaw assembly. The pivot pins pass through the upper and lower cage plates on the tong unit; as such, the jaw assembly must move along with the cage plates. The rear jaw, with respect to the cage plates, is stationary. The side plates, by virtue of the pivot pins, are rotatably attached with respect to the cage plates. The rear jaw and side jaws carry dies, typically two dies on the rear jaw and one die on each of the side jaws, for gripping a tubular. The multi-jaw assembly permits efficient gripping of undersize and/or out-of-round tubulars, and application of torque thereto, without damage to the tubular.

Abstract: A novel impact wrench is provided herein, which allows a user to set a target torque level, show the torque level in a display, and automatically stops the motor when the target torque level is reached. The impact wrench is constructed such that its electrical current would be at a maximum when it engages an impact operation, and at a minimum after the impact operation. The electrical current exhibits a periodic pulse and the periodic pulse is used to calculate the number of times of impacts. The torque level of the impact wrench could then be determined by the number of times of impacts.

Abstract: An apparatus to be used in a gripping assembly for gripping a cylindrical member is disclosed. The apparatus includes a jaw body, a gripping insert, and a rotatable camming member disposed between the jaw body and gripping insert. The rotatable camming member rotates in response to the applied clamping and rotational forces of the gripping assembly and operates to intensify the force provided by the jaw to the gripping insert which is engaged with a cylindrical member.

Abstract: Slips (1, 21, 41) for engaging any jointed, coiled or flexible tubular with substantially no scoring, gouging or scraping, such as when supporting a drill string in a borehole or gripping a tubular (2, 22) during the connection or disconnection of a tool joint or pulling a cable or pipeline; additionally, applying a pre-determined minimum gripping force in order to avoid rotary slippage when the weight of the string is insufficient to achieve a conventional slips action; additionally, including a coarse wedge (30, 50) to take up the extra travel of a worn tool joint or a tubular of smaller diameter, with a means to ensure that the coarse wedge acts before the fine wedge (29, 49) does and a means to ensure that the wedging action remains if the actuating force is removed; additionally, including a secondary slips (40) to interfere with the upset on the tool joint to avoid relying on friction to support the string and a means of integrating this with the gripping slips and ensuring that the secondary slips act

Abstract: A power tong (1) or back-up tong has a sliding jaw assembly (6) that may be advanced into the throat (4) of the tong for engagement with a pipe. A camming surface (11) on the inside circumference of the ring gear (10) advances the sliding jaw assembly into full engagement with the well pipe when the ring gear (10) is rotated with respect to the jaw assembly.

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 power tong or back-up tong has a jaw assembly that is advanced into engagement with a pipe through a cam follower that contacts the camming surface on the inside circumference of a ring gear, the cam follower being in the form of a series of roller elements arranged as a circulating bearing. In a preferred form, the roller elements are cylindrical roller bearings and the jaw assembly is mounted for sliding advancement towards the pipe to be engaged. In an alternate variant the cam follower includes an indexing guide that maintains the cylindrical roller bearings in proper alignment.

Abstract: Power tong jaws comprising one or more dies which are rotatable.

Abstract: A method for constructing a power tong jaw, including the steps of: (1) providing a substantially flat upper plate and a substantially flat lower plate; (2) providing at least two separately formed substantially elongated column members, at least one of the column members having a die insert groove formed therein; and (3) connecting the upper plate to the lower plate using the column members.

Abstract: A power tong apparatus for rotating a pipe comprises a tong housing and a ring gear, rotatably mounted in the tong housing. A top cage plate is positioned above an inner portion of the ring gear and a corresponding bottom cage plate is positioned below the inner portion of the ring gear. The cage plates form a cage rotatable with respect to the tong housing and the ring gear. A jaw is pivotally attached to the cage and grips the pipe when the ring gear is rotated with respect to the cage. The cage plates are fastened together by a fastener extending through a slot in the ring gear located between the inner and outer peripheries of the ring gear, such that the cage plates can rotate with respect to the ring gear through a limited arc.

Abstract: In a pivoting-jaw power tong, each primary camming surface of the rotary gear has a substantially linear rather than curved configuration. Each primary camming surface forms an acute angle with a radial line extending from the rotary gear centerline to the point where the primary camming surface transitions to its associated neutral recess. Accordingly, the radial distance to a point on any of the primary camming surfaces reduces linearly with increased distance from the neutral recess. Rotation of the rotary gear in either direction away from the neutral position thus results in a linearly progressive reduction in the distance from the center of rotation to the points where the pivoting jaws' cam followers contact the camming surfaces, thus increasing the force exerted by the dies of the jaws upon a tubular disposed within the jaws.

Abstract: An apparatus and a method for positioning a tubular relative to a tong is provided. In one aspect, a positioning tool may be mounted on a lower portion of the tong. The positioning tool includes a positioning member for determining a position of the tubular and a centering member for engaging the tubular. The positioning tool further includes an actuation device for actuating the centering member. The position of the tubular may be actively adjusted by actuating the centering member.

Abstract: A power tong or back-up tong has a jaw assembly that is advanced into engagement with a pipe through a cam follower that contacts the camming surface on the inside circumference of a ring gear, the cam follower being in the form of a series of roller elements arranged as a circulating bearing. In a preferred form, the roller elements are cylindrical roller bearings and the jaw assembly is mounted for sliding advancement towards the pipe to be engaged.