Abstract: A fail safe valve actuator is disclosed that is powered by an electric motor which drives through a wrap spring clutch and a centrifugal brake configured to absorb a portion of the energy released when the power fails and the valve stem is moved rapidly to its fail safe position by an actuator spring. The valve member is held in operating position by a solenoid. When power fails, a spring moves the valve stem in the other direction to move the valve member to its fail safe position. A torque limiting device is mounted adjacent the output end of a gear train to protect the gear train and the electric motor from the high torque created when the valve stem abruptly stops moving when the valve member reaches its operating position.

Abstract: The present invention is a surface controlled subsurface safety valve (SCSSV) for use in a well, preferably a hydrocarbon producing well. The SCSSV comprises a valve body having a longitudinal bore for fluid to flow through, a bore closure assembly, a pressure balanced drive assembly, and a fail safe assembly. The bore closure assembly is positioned and normally biased to close the bore to fluid flow. The drive assembly is coupled to the bore closure assembly for driving the bore closure assembly to an open position. The fail safe assembly is positioned and configured to hold the bore closure assembly in the open position in response to a hold signal and to release the valve to return to the safe, closed position upon interruption of the hold signal.

Abstract: A rotary cone drill bit for forming a borehole having a one-piece bit body with a lower portion having a convex exterior surface and an upper portion adapted for connection to a drill string. The drill bit will generally rotate around a central axis of the bit body. A number of support arms are preferably attached to pockets formed in the bit body and depend therefrom. Each support arm has an inside surface with a spindle connected thereto and an outer surface. Each spindle projects generally downwardly and inwardly with respect to the longitudinal axis of the associated support arm and the central axis of the bit body. A number of cone cutter assemblies equal to the number of support arms are mounted respectively on each of the spindles. The spacing between each of the support arms along with their respective length and width dimensions are selected to enhance fluid flow between the cutter cone assemblies mounted on the respective support arms and the lower portion of the bit body.