Abstract: The invention relates to a rotary device (101) for a down-the-hole hammer (1), which rotary device is accommodated in a rotation motor housing (3) and mounted behind a drill housing (2) for transferring a torque to a drill bit (8) and a pressurized drive fluid (22) to a striking mechanism (4) for the drill bit. The rotary device includes a cam curve with a plurality of drive lobes (28:1-28:3) and working chambers (30:1, 30:2, 30:3) along a circumference in the rotation motor housing (3), a rotor disc (38) carrying a plurality of radially movable vanes (40:1-40:12), which are accommodated in piston tracks (41:1-41:12) in the rotor disc.

Abstract: The invention concerns a method to establish communication between the inner cavity of a drill string and the surrounding material down in a drill hole (60) during the use of a down-the-hole drill unit with a drill string (10), a down-the-hole hammer drill (1), and a source of pressurized medium (11) that delivers a medium under pressure to the down-the-hole hammer drill.

Abstract: The invention concerns a drill bit, intended to be used with a down-the-hole drill and comprising a drill head (2) with a front surface provided with drill pins (3) and a shaft (4), whereby the shaft is narrower than the drill head and intended to be inserted in a manner that allows axial sliding into the end of a drill chuck that is a component of a down-the-hole drill and which shaft has a rear end part (6) that is somewhat thickened with a plane striking surface (7) against which a hammer piston (8) that is a component of the down-the-hole hammer drill is arranged to impact, that the drill head when viewed along its axial direction has a cylinder-shaped forward part (20) provided with cuttings channels (22), a rear cylinder-shaped part (21) that is located for the reception of drill cuttings at the same level or somewhat below the bottom (25) of the cuttings channels, whereby the diameter (D1) of the forward part is greater than the diameter (D2) of the rear part.

Abstract: An arrangement for a down-the-hole hammer drill, for use in soil consolidation by jet grouting, and comprising a cylindrical machine housing, an impact mechanism driven by pressurised fluid that impacts onto a drill bit mounted in a chuck in the machine housing that allows reciprocating motion, whereby the machine housing has a central supply line for the driving fluid to the impact mechanism in which channels in the drill bit constitute outlets for used driving fluid. The machine housing is provided with a grouting nozzle for jet grouting, that the grouting nozzle is directed in a sideways direction and arranged at the periphery of the wall of the machine housing, that a rinsing channel 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.

Abstract: The invention concerns a method to establish communication between the inner cavity of a drill string and the surrounding material down in a drill hole (60) during the use of a down- the-hole drill unit with a drill string (10), a down-the-hole hammer drill (1), and a source of pressurised medium (11) that delivers a medium under pressure to the down-the-hole hammer drill.

Abstract: 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.

Abstract: The invention concerns a drill bit, intended to be used with a down-the-hole drill and comprising a drill head (2) with a front surface provided with drill pins (3) and a shaft (4), whereby the shaft is narrower than the drill head and intended to be inserted in a manner that allows axial sliding into the end of a drill chuck that is a component of a down-the-hole drill and which shaft has a rear end part (6) that is somewhat thickened with a plane striking surface (7) against which a hammer piston (8) that is a component of the down-the-hole hammer drill is arranged to impact, that the drill head when viewed along its axial direction has a cylinder-shaped forward part (20) provided with cuttings channels (22), a rear cylinder-shaped part (21) that is located for the reception of drill cuttings at the same level or somewhat below the bottom (25) of the cuttings channels, whereby the diameter (D1) of the forward part is greater than the diameter (D2) of the rear part.