Patent ID: 7681672

Claim:
A cryogenic rapid boring system for rapidly boring a hole in a material comprising: a) a borehead having at least one pulsejet with a proximal end and a distal end located adjacent to said material intended to be bored; b) a cryogen supply unit for providing a cryogenic liquid to fill the pulsejet; c) a pulsejet having an expansion section located adjacent to the distal end; d) a tube having a freeze section located just proximal to the expansion section; e) at least one thermal unit capable of freezing cryogenic liquid into a plug and capable of melting the frozen plug located adjacent to the freeze section; f) at least one thermal unit capable of vaporizing the cryogenic liquid into a gas, and capable of cooling the expansion section; g) a controller coupled to the cryogen supply unit, the thermal units, and operating to activate: i. the cryogen supply unit to fill the pulsejet with the cryogenic liquid; ii. thermal units to freeze the plug at the freeze section; iii. thermal units to rapidly vaporize the cryogenic liquid, into the gas just distal to the frozen plug thereby causing the gas to force cryogenic liquid distal to the gas out of the distal end of pulsejet at a high velocity impacting said material thereby firing the pulsejet; iv. the thermal units to melt the frozen plug; and v. the thermal units to cool the expansion section.