Abstract: A femoral prosthesis has load shoulders for transferring normal loading to the femur at the proximal end to reduce stress shielding. The femur is resected to provide a flat load shoulder perpendicular to the axis of the femur. The prosthesis has a mating load shoulder in its proximal section which lands on the load shoulders formed in the femur. The prosthesis has a stem that extends downward to a distal end. The intermediate portion of the stem between the distal end and the proximal end is reduced in diameter to add flexibility. The distal end is substantially the diameter of the bone cavity.

Abstract: An inside blowout preventer for use in an earth boring drill string has features to reduce erosion. The blowout preventer has a valve body for connection into the drill string with a longitudinal passage extending through the body. The ball seat is located in the longitudinal passage. A ball storage location is located below the seat, and offset from the longitudinal passage. A ball is carried in the storage location during downward flow, and moves into the longitudinal passage to seat against the seat if the upward flow is sufficient. The storage location is located in an area of the longitudinal passage which has a much larger flow area than through the seat. The downward flow impinges on a portion of the ball. A communication passage extends from the storage location downward to a reduced diameter section of the longitudinal passage.

Abstract: A tool joint for earth boring drill pipe members has features that increase the amount of torque required to yield the connection. The tool joint has both external and internal make-up shoulders. The pin and box are dimensioned so that the box face contacts the external shoulder while there still is a clearance between the pin face and the internal shoulder. At normal make-up torque, the external shoulder will be tightened to its normal amount. The internal shoulder will tighten to its yield only if additional torque is encountered while drilling. The internal shoulder adds to the amount of torque required to yield the tool joint connection.

Abstract: A string of earth boring drill pipe has telemetry features. Each section of the drill pipe has a box tool joint on one end and a pin tool joint on the other end, with an insulated wire segment extending through the section. A contact ring is connected to one end of the wire segment and mounted to one of the tool joints. The contact ring has an exposed side. An annular contact member is connected to the other end of the wire segment and has an exposed side for contacting the exposed side of the contact ring when making up with another section. The contact member is laterally flexible and is mounted in an insulating member that is subjected to internal pressure in the drill string for urging the contact member toward the contact ring.

Abstract: An earth boring bit has features to reduce stress concentration. The earth boring bit is of the type having three bit legs, each bit leg having a depending bearing pin for rotatably carrying a cutter. An annular fillet is formed at the junction of the bearing pin and the bit leg for receiving a seal ring. To relieve stress above the fillet and on the inside surface of the bit leg, a depression is formed. The depression is formed in the inside surface of the bit leg with a lower edge commencing at the top of the fillet. The depression is curved in vertical cross-section and is located behind the backface of the cutter.

Abstract: An earth boring drill bit for large diameter shafts has an improved cutter arrangement. The drill bit has a cutter support member with a number of cutters mounted to it for disintegrating the earth formation face. At least one inner cutter is mounted near the center for cutting the center area. A number of gage cutters are mounted at the periphery to cut the gage area of the shaft. A number of intermediate cutters are spaced between the inner and gage cutters. Each intermediate cutter overlaps one-half of its width with an adjacent intermediate cutter.