Accession Number : ADD018467

Title :   Steerable Drillhead.

Descriptive Note : Patent, Filed 25 Jan 94, patented 7 May 96,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s) : Groves, Frank K

Report Date : 07 May 1996

Pagination or Media Count : 18

Abstract : An apparatus for boring a continuous underground tunnel and located inside of the forward end of a continuously rotating, pushed drillstring includes a housing for receiving pressurized drilling fluid, a nozzle including bores, attached forwardly to the housing for discharging the pressurized drilling fluid from the nozzle, a rotatable valve located in said housing for receiving and forwardly directing pressurized drilling fluid from the housing to the nozzle. The valve may be rotated in a 1st position, thereby directing the pressurized drilling fluid to a first set of bores in the nozzle for boring straight ahead. The valve may also be rotated in a 2nd position, thereby directing the pressurized drilling fluid to a second set of bores. By maintaining the valve in the 1st position for rotation of each revolution of the drillstring and then maintaining the valve in the 2nd position for the remaining rotation of each revolution of the drillstring, an off axis (curved) tunnel may be bored.

Descriptors :   *PATENTS, *DRILLS, TUNNELS, NOZZLES, PRESSURIZATION, UNDERGROUND, WATER JETS, DRIVE SHAFTS, ROTARY VALVES

Subject Categories : Machinery and Tools

Distribution Statement : APPROVED FOR PUBLIC RELEASE