Abstract: An earth drilling machine of the type having a boom mounted adjacent a mast to move a tubular between a lower, horizontal boom position and an upper, vertical boom position also includes a lifter configured to move a length of downhole tubular between a lower lifter position aligned with a tubular storage device and an upper lifter position aligned with the lower boom position. An automatic sequencing system includes multiple position sensors responsive to the position of at least the boom, the lifter and a length of downhole tubular at selected positions. A sequencing system is responsive to the position sensors for automatically coordinating movement of the lifter and the boom to reduce or eliminate delays occasioned by tubular handling.

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: A drilling apparatus of the type including a platform, a pair of spaced, parallel, substantially vertical guide rails, and a power swivel which is guided along the guide rails is provided with a pair of space support surfaces positioned on the underside of the swivel. In addition, a pair of collapsible pedestals are mounted on the platform, each pedestal positioned under a respective support surface such that the swivel rests on the pedestals when lowered toward the platform. These pedestals are provided with a collapse strength chosen such that the pedestals collapse in a controlled, progressive manner, substantially without damage to the guide rails, in the event the swivel falls from at least a predetermined height. In this way both the platform and any drill string attached to the swivel are protected from excessive loads associated with abrupt deceleration of the swivel, and the incidence of string breakage due to such abrupt deceleration is at least substantially reduced.

Abstract: A drilling ramp for a mobile drilling rig of the type having a wheeled vehicle and a mast substructure, wherein the substructure includes four legs, two of which serve to mount power hydraulic jacks and two of which serve to mount leg locating sockets. The ramp includes a substantially planar foundation structure adapted to support the drilling rig. Longitudinal guide bars and transverse chocks are mounted on the foundation structure to guide and position wheels of the drilling rig. Two jack locating members are mounted on the foundation structure, each of which defines a respective socket sized and positioned to interlock with respective ones of the two jacks included in the substructure. In addition, two manually operated jack screws are mounted on the foundation structure in alignment with the sockets on the rear legs of the substructure. Once the jacks have been engaged in the sockets of the ramp, the jack screws can be raised in order to provide support for the rear legs of the substructure.

Abstract: An automatically self-centering clamp for down-hole tubulars includes a frame which defines guides for two opposed clamping jaws. Each clamping jaw is pivotably attached to a rocker arm, and the two rocker arms are in turn pivotably attached to a tension member which extends therebetween. The tension member is mounted to the frame so as to be free to move in the direction of the clamping axis of the clamp as necessary to follow the movement of the jaws. A hydraulic cylinder is provided to pivot the rocker arms about the tension member, thereby positioning the jaws in the guides formed by the frame. A rotatable pivot plate is mounted to rotate within the frame, and link members are provided to link each of the rocker arms with a respective point on the pivot plate. The link members and the pivot plate act to maintain the rocker arms in symmetrical positions such that the jaws remain centered about a predetermined clamping axis for a wide range travel of the jaws.