Pulsed Supersonic Jet with Local High Speed Valve

Abstract

A pulsed supersonic jet excavator uses a short duration blast of air to excavate using a minimum amount of air and a minimum reaction force. This device uses a fast acting valve to create a jet of air that lasts about as long as it takes to develop. The result is a device that works much more efficiently than existing air jet excavators. This device can be mounted on a small robot and allow it to dig, whereas a normal backhoe type excavator would just lift the robot when attempting to dig in packed earth.

I claim: 
     
         1 . A pulsed supersonic jet excavator consisting of
 A supersonic nozzle including a converging portion and a diverging portion.   A high-speed valve located within 10 nozzle diameters of said nozzle,   Said nozzle and valve being attached to a remotely controlled manipulation means.   
     
     
         2 . The device as in  claim 1 , including a local air storage chamber which is periodically dumped through the valve 
     
     
         3 . The device as in  claim 1 , including a heater to heat the air. 
     
     
         4 . The device as in  claim 1 , including a poppet valve wherein the downstream pressure motivates the valve towards an open position. 
     
     
         5 . The device as in  claim 1 , including a robot to carry said device. 
     
     
         6 . The device as in  claim 1 , including a video camera to feed data to a remote location. 
     
     
         7 . The device as in  claim 1 , including an attachment to a vehicle. 
     
     
         8 . The device as in  claim 1 , with including a metal detector to detect buried objects. 
     
     
         9 . The device as in  claim 1 , wherein the volume of the fluid connection between said high speed valve and said nozzle is less than 5 times the volume of said nozzle 
     
     
         10 . The device as in  claim 2 , including a pressure transducer to measure the pressure in said storage chamber. 
     
     
         11 . The device as in  claim 1 , Said valve open duration being less than 10 times to the time required for the supersonic jet to develop to its full supersonic length 
     
     
         12 . The device as in  claim 1 , with a local video camera with positioning means to observer the excavation.