Patent ID: 6648084
Filing Date: 2003-11-18
Classification: E02D

Abstract:
A head for injecting liquid under pressure from a borehole to break up soil, said head being mounted at the end of a drill string, said string including liquid feed means for feeding liquid under pressure, said head comprising:a body having an outside wall and a top end for connection to the bottom end of the drill string; at least one injection nozzle mounted in said body, the inlet diameter of said nozzle being equal to d, said nozzle possessing an axis (x-xâ€²); and duct-forming means for connecting the feed of liquid to the inlet of said nozzle, said duct-forming means presenting a mean line having a first end connected to the bottom end of said liquid feed means and having a second end connected to the nozzle tangentially to said axis (x-xâ€²), said mean line being defined by at least one curved portion presenting a radius of curvature that varies continuously, the right section of said duct-forming means decreasing regularly over at least half of its length from its first end to its second end.