ARRANGEMENT FOR A DOWN-THE-HOLE HAMMER DRILL FOR USE IN SOIL CONSOLIDATION THROUGH JET GROUTING

摘要

The invention concern an arrangement for a down-the-hole hammer drill (1), particularly for use in soil consolidation through a process known as "jet grouting", and comprising a principally cylindrical machine housing (2), an impact mechanism (3) driven by pressurised fluid that, mounted in the machine housing, is arranged to give impacts onto a drill bit (5) fixed mounted in a chuck (4) in the machine housing in a manner that allows reciprocating motion, whereby the machine housing has a central supply line (6) for the driving fluid to the impact mechanism in which channels in the drill bit constitute outlets for used driving fluid. For improved efficiency during jet-grouting, the machine housing (2) is provided with a grouting nozzle (7) for jet grouting, that the grouting nozzle is directed in a sideways direction and arranged at the periphery of the wall (8) of the machine housing, that a rinsing channel (9) for conducting a grouting mixture through the machine housing to the said grouting nozzle is arranged whereby the rinsing channel for the grouting mixture is separate from the supply line for the driving fluid of the impact mechanism.