Abstract: An auto-centering structural bearing transfers vertical loads to a supporting structure while preventing transfer of lateral loads. In one embodiment, the structural bearing includes: parallel lower, middle, and upper bearing plates; a lower roller bed sandwiched between the lower and middle bearing plates and laterally displaceable in a first direction; an upper roller bed sandwiched between the middle and upper bearing plates and laterally displaceable in a second direction; lower centering means including springs compressible by lateral displacement of the middle bearing plate and the lower roller bed in the first direction; and upper centering means comprising springs compressible by lateral displacement of the upper bearing plate and the upper roller bed in the second direction. Upon removal of loads causing such lateral displacements, the springs will rebound to their unstressed states, thereby returning the displaced bearing plates and roller beds to their centered positions.

Abstract: A mechanism for adjusting the relative angular orientation of two coaxial components includes a mandrel having a cylindrical central section between upper and lower splined sections, a sleeve rotatably and slidably disposed around the mandrel's central section, and generally cylindrical upper and lower ratchet members positioned, respectively, about the mandrel's upper and lower splined sections. The ratchet members have internal grooves which receive the mandrel splines for torsional load transfer while permitting limited rotation relative to the mandrel, but their axial positions relative to the mandrel are fixed. The upper and lower ends of the sleeve have circumferentially-arrayed ratchet teeth engageable, respectively, with corresponding teeth on the upper and lower ratchet members. The central sleeve has torque-transferring external splines slidable within matching grooves on the inner surface of a cylindrical tool housing enclosing the mechanism.

Abstract: An auto-centering structural bearing transfers vertical loads to a supporting structure while preventing transfer of lateral loads. In one embodiment, the structural bearing includes: parallel lower, middle, and upper bearing plates; a lower roller bed sandwiched between the lower and middle bearing plates and laterally displaceable in a first direction; an upper roller bed sandwiched between the middle and upper bearing plates and laterally displaceable in a second direction; lower centering means including springs compressible by lateral displacement of the middle bearing plate and the lower roller bed in the first direction; and upper centering means comprising springs compressible by lateral displacement of the upper bearing plate and the upper roller bed in the second direction. Upon removal of loads causing such lateral displacements, the springs will rebound to their unstressed states, thereby returning the displaced bearing plates and roller beds to their centered positions.

Abstract: A mechanism for adjusting the relative angular orientation of two coaxial components includes a mandrel having a cylindrical central section between upper and lower splined sections, a sleeve rotatably and slidably disposed around the mandrel's central section, and generally cylindrical upper and lower ratchet members positioned, respectively, about the mandrel's upper and lower splined sections. The ratchet members have internal grooves which receive the mandrel splines for torsional load transfer while permitting limited rotation relative to the mandrel, but their axial positions relative to the mandrel are fixed. The upper and lower ends of the sleeve have circumferentially-arrayed ratchet teeth engageable, respectively, with corresponding teeth on the upper and lower ratchet members. The central sleeve has torque-transferring external splines slidable within matching grooves on the inner surface of a cylindrical tool housing enclosing the mechanism.

Abstract: A downhole rotational rate control apparatus, adapted for coupling to the lower end of a drill string, includes a progressive cavity (PC) motor, a driveshaft, a mud flow control valve, and an electronics section. Drilling mud flowing downward through the drill string is partially diverted to flow upward through the PC motor and out into the wellbore annulus, with the mud flow rate and, in turn, the PC motor speed being controlled by the mud flow control valve. The control valve is actuated by a control motor in response to inputs from a sensor assembly in the electronics section. The PC motor drives the driveshaft and a controlled downhole device at a specific zero or non-zero rotational rate. By varying the rotational rate of the PC motor relative to the rotational rate of the drill string, the tool face orientation or non-zero rotational speed of the controlled device in either direction can be varied in a controlled manner.

Abstract: Pipe handling apparatus to move tubulars from a horizontal position on a piperack adjacent a well bore to a vertical position over the wall center or mousehole. A bicep arm assembly is pivotally connected to a base plate. A forearm assembly is pivotally attached to the distant end of the bicep arm assembly and a gripper head is pivotally connected to the distant end of the forearm assembly. The bicep arm assembly is mounted to the structure of the drill rig.