1
William N Schoeffler: Valved jet device for well drills. Pioneer Fishing and Rental Tools, John D Jeter, October 7, 1986: US04615399 (35 worldwide citation)

A column of drill collars have holes or jets extending radially from the collar bore through the collar wall. A wash pipe extends full length through the bore of the perforated collars, so sized as to leave an annular flow space between the wash pipe and the collar bore wall. A remote control select ...


2
Schoeffler William N: Valved jet device for well drills. April 16, 1974: US3804186 (6 worldwide citation)

Valve members that are relatively rotatable through only a limited amount constitute a lost motion rotary drive connection between a drill string and a drill head. When the drill string is driving the drill head in one direction the valve members are open to provide free flow of drilling mud to the ...