Abstract: A portable excavator having a tube to point a supersonic gas stream at a buried object. The excavator includes a movable member disposed within the conduit to pulse gas passing through the conduit and a supersonic gas nozzle at the exit of the conduit. Compressed gas delivered to the conduit exits the nozzle in a pulsed manner at two to three Hz. The movable member includes a piston which blocks gas from flowing through the conduit by the biasing force of a spring. When the force to the pressure differential across the piston exceeds the biasing force, the piston moves and allows gas to flow through the conduit until the force from the pressure differential across the piston is less than the biasing force.

Abstract: A portable excavator having a tube to point a supersonic gas stream at a buried object. The excavator includes a movable member disposed within the conduit to pulse gas passing through the conduit and a supersonic gas nozzle at the exit of the conduit. Compressed gas delivered to the conduit exits the nozzle in a pulsed manner at two to three Hz. The movable member includes a piston which blocks gas from flowing through the conduit by the biasing force of a spring. When the force from the pressure differential across the piston exceeds the biasing force, the piston moves and allows gas to flow through the conduit until the force from the pressure differential across the piston is less than the biasing force.

Abstract: An integrated safe excavation apparatus utilizing supersonic air jets coupled with high flow, pneumatic vacuum transport and a unique separation system to excavate earth and other like material for the purpose of repairing, replacing or installing buried utility lines, remediating contaminated soils, uncovering buried objects containing discarded hazardous waste, safely exposing unexploded ordnance and other like operations.

Abstract: An excavation head, mounted on one end of a telescoping hollow boom, has nozzles for directing jets of high speed air at an excavation face to loosen soil. A vacuum transport pipe extends from the excavation head through the hollow of the boom to a spherical joint. The spherical joint movably joins the other end of the boom to a primary separator. The primary separator is a chamber for disentraining loosened soil from air flowing through the primary separator. A primary air lock is fixed to the lower portion of the primary separator for expelling soil from the primary separator. A secondary separator is joined to the primary separator by way of a separator connector pipe. A secondary air lock is fixed to the lower portion of the secondary separator for expelling soil from the secondary separator. A positive displacement vacuum pump has its vacuum side pneumatically connected to the secondary separator.

Abstract: A high wall mining system including a continuous mining machine, a remote control station outwardly of the high wall from which extend electric cables wound on cable reels which extend to the continuous mining machine enabling the operator to control the machine based upon television pictures transmitted to the control station from television cameras on the machine and the signals from laser and sonar guidance systems provided at the control station in cooperation with elements on the continuous mining machine and an extensible and retractable vacuum air conveyor system for the coal recovered by the mining machine.