Abstract: An example apparatus for controlling the direction of drilling a borehole includes an outer housing having non-uniform stiffness and an inner housing at least partially within and rotationally independent from the outer housing and having non-uniform stiffness, A drive shaft may be at least partially within the inner housing. At least one of the outer housing and the inner housing may include a tubular structure with at least one of multiple materials with different stiffness, and a portion with less structural material than another portion.

Abstract: An example slip-ring interface may include a first section and a second section rotationally independent from the first section. At least one conductor path between the first section and the second section may be selectively associated with and dedicated to the transmission of signals with a first signal type. At least one conductor path between the first section and the second section may be selectively associated with and dedicated to the transmission of signals with a second signal type. If error conditions occur, the signal types associated with one or more of the conductor paths may be changed so that signals of both the first and second signal types are transmitted across the interface.

Abstract: An example apparatus for controlling the direction of drilling a borehole includes an outer housing having non-uniform stiffness and an inner housing at least partially within and rotationally independent from the outer housing and having non-uniform stiffness, A drive shaft may be at least partially within the inner housing. At least one of the outer housing and the inner housing may include a tubular structure with at least one of multiple materials with different stiffness, and a portion with less structural material than another portion.

Abstract: An example slip-ring interface may include a first section and a second section rotationally independent from the first section. At least one conductor path between the first section and the second section may be selectively associated with and dedicated to the transmission of signals with a first signal type. At least one conductor path between the first section and the second section may be selectively associated with and dedicated to the transmission of signals with a second signal type. If error conditions occur, the signal types associated with one or more of the conductor paths may be changed so that signals of both the first and second signal types are transmitted across the interface.

Abstract: A steering tool for use in drilling a borehole, including a tubular housing, a tool actuating device movably supported within the housing, a plurality of hydraulically actuated steering devices circumferentially spaced about the housing, and a hydraulic control system interposed between the tool actuating device and the steering devices for converting an actuating movement of the tool actuating device to independent actuation of the steering devices.

Abstract: A steering tool for use in drilling a borehole, including a tubular housing, a tool actuating device movably supported within the housing, a plurality of hydraulically actuated steering devices circumferentially spaced about the housing, and a hydraulic control system interposed between the tool actuating device and the steering devices for converting an actuating movement of the tool actuating device to independent actuation of the steering devices.