Abstract: The present invention provides a head for injecting a fluid under pressure for breaking up the ground from a borehole and mounted at the end of a string of rods. The body of the drilling head has a bottom wall for mounting a mechanical drilling tool having a feed pipe, at least one injection nozzle, and duct-forming means for connecting the feed pipe with liquid at the inlet of said nozzle, the duct-forming means presenting a mean line having a radius of curvature that varies continuously, the right section of said duct-forming means decreasing regularly over at least half its length from its first end towards its second end. The injection head further comprises at least one pipe for feeding said mechanical tool, said pipe being connected at a first end to said duct-forming means and at a second end to a chamber disposed at the bottom end of said injection head and fitted with a controllable shutter member interposed between said chamber and the pipe for feeding said mechanical tool.

Abstract: The present invention provides a head for injecting a fluid under pressure for breaking up the ground from a borehole and mounted at the end of a string of rods. The body of the drilling head has a bottom wall for mounting a mechanical drilling tool having a feed pipe, at least one injection nozzle, and duct-forming means for connecting the feed pipe with liquid at the inlet of said nozzle, the duct-forming means presenting a mean line having a radius of curvature that varies continuously, the right section of said duct-forming means decreasing regularly over at least half its length from its first end towards its second end. The injection head further comprises at least one pipe for feeding said mechanical tool, said pipe being connected at a first end to said duct-forming means and at a second end to a chamber disposed at the bottom end of said injection head and fitted with a controllable shutter member interposed between said chamber and the pipe for feeding said mechanical tool.

Abstract: The invention provides a head for injecting a liquid under pressure from a borehole to break up the soil, said head being mounted at the end of a drill string including a liquid feed for feeding a liquid under pressure. The head comprises a body and an outside wall, the body having at least one injection nozzle mounted therein, the nozzle having an inlet diameter equal to d and presenting an axis (x-x′), the body also having a tube. The tube presents a mean line having a first end connected to the bottom end of the liquid feed and having a second end connected to the nozzle tangentially to the axis (x-x′). The mean line is defined by at least one curved portion presenting a radius of curvature that varies continuously. The right section of the tube decreases regularly over at least half of its length from its first end to its second end.

Abstract: The invention provides a head for injecting a liquid under pressure from a borehole to break up the soil, said head being mounted at the end of a drill string including liquid feed means for feeding a liquid under pressure. The head comprises a body and an outside wall, the body having at least one injection nozzle mounted therein, the nozzle having an inlet diameter equal to d and presenting an axis x,x′, the body also having duct-forming means. The duct-forming means present a mean line having a first end connected to the bottom end of the liquid feed means and having a second end connected to the nozzle tangentially to the axis x,x′. The mean line is defined by at least one curved portion presenting a radius of curvature that varies continuously. The right section of the duct-forming means decreases regularly over at least half of its length from its first end to its second end.