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.

Abstract: The invention concerns a method and a device for directional drilling of a hole, in particular when drilling curved holes for mining, drift mining or similar, whereby a drill support is used in the form of a flexible continuous drill tube with a proximal end and a distal end, that at the end of the drill support distal end is connected a down hole assembly comprising a drill bit for forming a drill string, which is fed into the gradually forming hole. To avoid and minimize the occurrence of “stick slip” during directional drilling, according to the method, the drill support while drilling is taking place is held fixed at its proximal end against rotation outside the borehole and the rotating motion for indexing the drill bit around an axis extending in the direction of drilling is performed in the area between the drill support's distal end and the drill bit while drilling is in progress.

Abstract: In a liquid downhole drilling machine, the guiding bushing (31) for the drill bit is rotatably journaled in the housing (11, 12) and, via a one-way coupling (29), coupled to a turning sleeve (22) that has axial ridges (24) that bound a number of chambers (25, 26, 27) and form turning pistons for turning the turnable sleeve to and fro. A number of these chambers are coupled to be pressurized and depressurized simultaneously with said pressure chamber (47) with the piston area (46) for urging the piston hammer (30) forwards. As a result, the drill bit (13) will be indexed a defined angle between each impact so that the button inserts of the drill bit will change contact points with the rock between every impact and fragment the rock efficiently. The drill tube is not rotated.

Abstract: A hydraulic drill string device can be in the form of a percussive hydraulic in-hole drilling machine that has a piston hammer (50) with an axial through hole (51) into which a tube (35) extends. The tube forms a channel for flushing fluid from a spool valve (62) and the tube wall contains channels (40) with ports (41,42) cooperating with the piston hammer for controlling the valve.