William N Schoeffler: Remote control selector valve. Petro Design, John D Jeter, April 7, 1987: US04655289 (52 worldwide citation)

A control system for use on fluid conducting pipe strings in earth boreholes to permit cycling of fluid flow between preselected flow rates to change conditions downhole as a result of surface exercise of fluid flow controls. A resulting change of state downhole is indicated by a change in fluid flo ...

William N Schoeffler: Angle deviation tool. Petro Design, John D Jeter, April 7, 1987: US04655299 (40 worldwide citation)

A normally straight drill string component for use just above a downhole drilling motor, or directional jet, that can be caused to be alternately straight or bent by cycling the drilling fluid flow rate between selected flow rate limits by use of controls at the earth surface.

Falgout Sr Thomas E, Schoeffler William N: Apparatus for controlling the operation of a downhole tool. Petro Design, November 9, 1988: GB2204344-A (2 worldwide citation)

A body and driveshaft extension for down hole drilling motors to allow the down hole assembly to operate as part of a drill string responsive to selected manipulations of the drilling fluid flow rate, carried out at the earth surface, to assume either a straight hole drilling configuration or a dire ...