DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENT

[0013] While those skilled in the relevant art will recognize that various changes can be made from the disclosed embodiment of the invention, without departing from the spirit of the invention, with reference to the drawings one presently preferred embodiment will be described.

[0014] It is understood that the term “power tong,” as used in this application, encompasses any form of powered device used to make up and/or break out threaded tubular connections (on any type of tubular, including drill pipe, tubing, casing, etc.), and includes drill pipe tongs, casing tongs, “make/break” devices, etc. It is further understood that the invention may have application in many different settings; as a matter of convenience only, the invention is described in connection with its deployment on a drilling or workover rig. However, it is equally applicable to positioning tongs in a shop environment, for example.

[0015] FIG. 1 best serves to illustrate a typical installation of the power positioner on a rig floor, in proximity to a threaded tubular connection to be made up or broken out, such as a drill pipe connection. While the power positioner may be installed at various desired locations about the rig floor, one possible location is to one side of the rotary table, to permit ready access to tubulars both in the rotary and in the mousehole. FIG. 1 shows the apparatus in a retracted position, with the tong in a stored position substantially over the pedestal. With the power positioner mounted in front of the drawworks, in the retracted position the entire apparatus (including the power tong mounted thereon) is out of the way of most rig operations, yet is positioned to readily be placed into service when needed.

[0016] FIG. 2 is an exploded view of the apparatus. With reference to FIGS. 1 and 2, power positioner 10 comprises a vertically movable pedestal 20 mounted on or in a desired location, for example mounted on a rig floor and extended down below the rig floor. Alternatively, pedestal 20 may be mounted on the floor of a shop or other similar setting. Preferably, pedestal 20 is vertically movable by hydraulic means, although mechanical means such as a roller and flat gear combination could be used. As can additionally be seen in FIG. 2, a base 30 is rotationally mounted on pedestal 20, preferably atop pedestal 20. A powered pinion and ring gear assembly 40 permits controlled rotation of base 30 on pedestal 20. A carriage 40 is slidably disposed on base 30, and in the presently preferred embodiment, carriage 40 rides on a plurality of rollers 60 which are disposed between base 30 and carriage 50, preferably mounted on base 30.

[0017] A means for moving carriage 50 on base 30 is provided. In the preferred embodiment, this means for moving comprises at least one, and preferably a pair of hydraulic cylinders 70 mounted between base 30 and carriage 50. Actuation of hydraulic cylinders 70 moves carriage 50 between a retracted position and an extended position, as is later described.

[0018] Both horizontal and vertical movement of a power tong is provided by a lift assembly preferably mounted on carriage 50, from which a power tong is suspended. In a presently preferred embodiment, the lift assembly comprises at least one, and preferably a pair, of arms 80 rotatably mounted on carriage 50. A means for rotating arms 80 about their pivot point is provided. The presently preferred embodiment comprises an extensible means such as hydraulic cylinder 90 connected between arms 80 and carriage 50, which rotates arms 80 with extension and retraction of the hydraulic cylinder. Preferably, a gambrel 100 joins arms 80, and power tong 110 is suspended from gambrel 100. Gambrel 100 typically suspends power tong 110 such that power tong 110 can swing back and forth to a limited degree, with rotation of gambrel 100 about its longitudinal axis. An elastic means 130, such as a spring or pneumatic cylinder, can be disposed between power tong 110 and gambrel 100, to provide some “cushioning” to the weight of power tong 110 hanging from gambrel 100, and additionally to permit power tong 110 to move up or down while engaged on the tubular, to permit the tong to compensate for thread makeup and breakout (either extending or contracting). Alternatively, power tong 110 could be mounted to arms 80 via different configurations of rigid members, or even by flexible members such as cables and the like, from arms 80.

[0019] While some degree of movement may be desirable for final positioning of power tong 110 on a connection, preferably a stabilizer 120 is provided, that connects between power tong 110 or the means by which it is suspended from arms 80, and some other part of the apparatus, for example to arms 80. As can be seen in the figures, one embodiment has stabilizer 120 mounted between arm 80 and gambrel 100. Stabilizers 120 may be hydraulic, pneumatic, or spring cylinders, etc. to dampen and restrain the degree to which power tong 110 can swing.

[0020] The preferred embodiment of the invention can also comprise controls of forms well known in the relevant art to control rotation of the base on the pedestal; movement of the pedestal up and down; movement of the carriage back and forth on the base; and movement of the arms. Further, controls may be provided to operate the various aspects of the power tong unit itself. Such controls may be connected to the various parts of the power positioner and power tong unit via a hydraulic line/electric cable umbilical, routed to a conveniently placed control panel; or communication via radio waves between controls and the controlled mechanisms can be used. Yet another embodiment has controls for both the power positioner and the power tong unit mounted on the power tong unit, for easy manipulation by the power tong operator.

[0021] Operation of the Power Positioner

[0022] FIGS. 3-6 illustrate the power positioner in different positions, in a typical sequence of use in positioning a power tong unit onto a tubular threaded connection. While the particular embodiment illustrated is on a rig floor setting, as earlier mentioned it is understood that the scope of the invention lends itself to use in other settings, such as a shop for manipulation of bottom hole assemblies, etc.

[0023] In FIG. 3, the apparatus, and hence power tong 110, is in a substantially fully retracted position, that is, as far back from the tubular as can be positioned. As can be seen, carriage 50 is retracted on base 30 (to the right in FIG. 3 as illustrated) by hydraulic cylinders 70, and arms 80 are pulled back via hydraulic cylinders 90 to their fully retracted position. Power tong unit 110 is therefore out of the way of other rig operations. FIG. 3 illustrates a key space saving aspect of the invention, wherein the pedestal is (in a retracted position) largely below the rig floor (or shop floor or the like).

[0024] FIG. 4 is a next exemplary position in the course of moving power tong 110 from a retracted position to a position around the tubular. Cylinders 70 are extended to rotate arms 80 to a forward position. In this figure, carriage 50 is still in a retracted position on base 30.

[0025] FIG. 5 next shows power tong 110 in a position around the tubular. Carriage 50 has been advanced on base 30, and the combination of lateral movement of carriage 50 and arms 80 is sufficient to place power tong 110 in a desired position around the tubular. It is understood that the combination and sequence of lateral movement of power tong 110, by both movement of carriage 50 and rotation of arms 80, can be in any desired sequence, and to any desired degree. The dimensions of the various components can be adjusted to suit differing settings.

[0026] FIG. 6 additionally shows the component of vertical movement of power tong 110 achieved by vertical movement of pedestal 20. Rotation of base 30 on pedestal 20 can give yet another degree of movement of power tong 110.

[0027] It can be readily appreciated that a power tong can thus be positioned by the present invention in a vertical plane, by a combination of pedestal movement and rotation of the arms; and in a horizontal plane, by a combination of movement of the carriage on the base, rotation of the arms, and rotation of the base on the pedestal.

[0028] It can be readily seen by the figures and description, that the various components of the invention permit movement of the power tong in both horizontal and vertical directions, and that different positions can be readily achieved via a combination of such movements.

[0029] While the description set forth above contains many details of the preferred embodiment, same are made in order to disclose one of the presently preferred embodiments and not by way of limitation. Various changes could be made while staying within the scope of the present invention, for example dimensions of the various elements; scope or extent of movement of the various mechanisms of the power positioner; the power positioner can be used to manipulate power tongs used to make up and/or breakout any type of threaded tubular, including drill pipe, tubing, or casing; the invention can be deployed in the field on any type of rig or other similar setting, or can be used in a shop.

[0030] Therefore, the scope of the invention is to be measured not by the disclosed embodiments, but by the scope of the appended claims and their legal equivalents.