Abstract: Compact casing tongs include a tube which is secured to a connector, the connector in turn being supported and rotated by a quill of a top head drive assembly. The lower end of the tube regidly supports a set of cams which define multiple recesses. A jaw is mounted in each recess, and each of the jaws is connected to a brake ring positioned outside the tube. By externally braking the brake ring while the quill connector body is rotated the jaws are shifted out of the recesses to grip the exterior of a casing positioned within the tube. The tube is dimensioned to ensure that the jaws engage the body of the casing beneath the upper collar of the casing.

Abstract: An earth drilling machine includes a crown block assembly, a travelling block assembly and a drawworks. The drawworks includes a drum which rotates about a drum axis. The drum axis is oriented at right angles to a fast line plane defined by a fast line sheave included in the crown block assembly. In this way, the fleet angle between the drum and the fast line sheave is kept substantially equal to zero. Various sheave arrangements are described which combine proper selection of sheave pitch diameter, sheave axis angle, and sheave placement to ensure that the fleet angle of all of the sections of line extending between the crown block assembly and the travelling block assembly are reeved with a fleet angle exactly equal to zero. In this way line wear is reduced and the height, weight and windage of the mast are all minimized.

Abstract: A top head drive cooling system is provided for an earth drilling machine of the type having a mast, a top head drive assembly mounted for movement along the mast, a quill included in the top head drive assembly, and an electric motor for rotating the quill. This cooling system includes an air duct mounted to the mast and defining a slot extending along the mast. The slot is sealed by a pair of flexible resilient lips which bridge the slot, and a blower is situated at ground level to blow cooling air into the air duct. A conduit is provided on the top head drive assembly, and the conduit extends between the lips into the air duct and conducts air from the air duct to the electric motor. The portion of the conduit which extends into the air duct is preferably tapered at both ends in order to provide a sliding seal against the lips. A position measuring system is coupled to the conduit and is positioned within the air duct.

Abstract: A top head drive assembly for a drilling machine includes a wrench assembly used to make up and break out threaded connections. This wrench assembly is mounted for axial movement on rails of the top head drive assembly, and is positioned immediately under the quill. The top head drive assembly also includes a tubular support assembly which includes slip type inserts for supporting a string of down hole tubulars. This support assembly can be pivoted out of alignment with the drilling axis or can be locked in alignment with the drilling axis. A plurality of centering elements are mounted under the support assembly and are movable to center the upper end of a tubular for insertion into the tubular support assembly. Preferably, both the top head drive assembly load beam and the support beam of the support assembly are formed of box sections having converging side plates and internal diagonal brace plates which transmit downward forces on the beam into forces tending to cause the side plates to diverge.

Abstract: A top head drive assembly includes a tubular quill having a central passageway aligned with an axis. The quill is supported for rotation on a load beam included in the top head drive assembly such that the quill is movable along the axis through a range of travel sufficient to provide thread protection to the down hole tubulars during tubular handling operations. Splines drivingly connect the quill with a transmission such that the transmission is operative to rotate the quill throughout the range of travel of the quill along the axis. A blowout preventer valve is mounted in an upper part of the quill to move axially and rotationally with the quill in order to eliminate sliding or rotary seals between the blowout preventer valve and the drill string.

Abstract: An internal wrench for an earth drilling machine of the type having a mast, a top head drive assembly mounted for movement along the mast and a quill rotated by the top head drive assembly includes a body having an upper end and a lower end sized to fit within a length of casing. The upper end of the body is mounted to the quill for rotation with the quill and several jaws are mounted to the lower end of the body to move between an extended position in which the jaws engage in interior surface of the casing to rotate the casing with the body, and a retracted position in which the jaws are out of engagement with the interior surface. The jaws are selectively moved between the extended and retracted positions in response to rotation of the body by a system which includes a drag ring which operates the jaws and a friction brake which engages the drag ring. A plug is mounted to an intermediate portion of the body to mate with threads at the upper end of the casing to seal off the casing.

Abstract: An elevator for drill pipe which includes at least two jaws for supporting a length of pipe and structure for maintaining the jaws in clamping engagement with the pipe. The structure includes linkage means coupled to the jaws for maintaining the jaws clamped to the pipe when the elevator and pipe are urged apart by gravity due to the weight of the pipe as when the pipe is raised or otherwise supported by the elevator. Additionally or alternatively, the elevator includes a pressure actuator assembly connected to the jaws for applying a positive force against the jaws for maintaining the jaws clamped to the pipe independent of the effect of gravity and, thus, independent of the orientation of the elevator.

Abstract: A rack for supporting drilling tubulars such as drill pipe, collars and the like includes a base and a rail. The rail is coupled to the base by means of two columns, each of which is provided with threads such that the tilt angle of the rail with respect to the base can be adjusted to provide gravity feeding of drilling tubulars to either end of the rail. The rail is provided with two pivotably connected stop plates which move in opposition. The stop plates are controlled by means of an air cylinder to allow only one drilling tubular at a time from those stored on the rack to roll off the end of the rail. Furthermore, both stop plates can be retracted below the level of the rail so as not to interfere with the movement of tubulars onto the rack. The combination of the tiltable rail and the two stop plates provides a rack which can be used to control movement of drilling tubulars on to and off of the rack with a minimum of manpower requirements.

Abstract: A self-locking and unlocking elevator for use with drill pipe is disclosed which, in a specific embodiment, includes a pair of jaws, each shaped to support a length of pipe; and central and upper linkage assemblies, for opening and closing the jaws about a section of drill pipe. The invention also includes a ratchet mechanism for locking the jaws open to receive or release a length of pipe, or to allow changing the clamping surfaces to accommodate different sizes of pipe; and for unlocking the jaws to allow closure over and clamping of a length of pipe.

Abstract: A platform positioning system for a drilling device of the type which includes a support structure and a transfer arm pivotally connected to the support structure to rotate about a first axis is disclosed. This platform positioning system includes a platform which is pivotally connected to the support structure to rotate about a second axis, and a rod which is mounted between the transfer arm and the platform. The position of the arm and platform axes and the length of the rod are selected such that the transfer arm automatically and progressively raises the platform to the raised position by means of the rod as the transfer arm moves to the raised position, and the transfer arm automatically and progressively lowers the platform to the lowered position by means of the rod as the transfer arm moves to the lowered position.

Abstract: A clamp for drilling tubulars such as drill pipes includes a jaw which defines a cylindrical recess. A cylindrical insert is rotatably mounted within the recess. This insert defines a cylindrically symmetrical toothed surface positioned to grip and frictionally engage the clamped tubular, and a cylindrically convex positioning surface configured to cooperate with the cylindrical recess to hold the insert in place in the jaw. The insert is mounted in the jaw so as to rotate freely within a selected range of rotational positions in order to allow the insert to orient itself as necessary to maximize the area of contact between the insert and the clamped tubular over a range of tubular diameters. The insert is reversible in the recess so as to allow the insert to be positioned in the jaw as necessary to maximize frictional engagement with the clamped tubular in a selected direction of rotation.