Abstract: A method for estimating wear of a drill bit in percussive rock drilling. A percussion device is configured for generating shock waves in a drill bit for breaking rock. The method includes, during drilling determining a percussion frequency of the percussion device; and estimating wear of the drill bit based on the determined percussion frequency of the percussion device and a model representation of the wear of the drill bit as a function of percussion frequency, wherein the model representation is configured to output the estimated wear of the drill bit utilizing the determined percussion frequency as input signal.

Abstract: Damping device for a percussion device of a hydraulic rock drilling machine (1) with a striking direction (R), including a damping piston (5) for action in an axial direction against a tool, wherein the damping piston (5) exhibits a first piston portion (6), which is received in a first damping chamber (7) and a second piston portion (8), which is received in a second damping chamber (9). In operation, in a normal striking position of said percussion device, the damping piston (5) is set against a fixed stop (19) against movements in the striking direction. A damping slot (10) is established between the first (7) and the second (9) damping chamber in all axial positions of the damping pistons, and the first damping chamber (7) is pressurized with a hydraulic pressure. The invention also concerns a percussion device and a rock drilling machine.

Abstract: The present invention relates to a method for driving a mining and/or construction machine, where said machine is arranged to be controlled by an operator by means of maneuvering means, where said operator, when driving said machine, provides steering commands by means of said maneuvering means for maneuvering said machine. The method comprises, when said machine is being driven in an environment having at least a first obstacle: when said machine is within a first distance from said first obstacle, estimate a first path that has been requested by said operator by means of said steering commands, by means of a control system, determining whether said machine when moving according to said requested first path will be driven within a second distance from said first obstacle, and when it is determined that said machine, when travelling according to said first path, will be driven within said second distance from said first obstacle, retard said machine by means of said control system.

Abstract: Rock drilling machine (10) comprising a piston that is arranged to move back and forth in a chamber (12a, 12b) when the rock drilling machine (10) is in use, a cavitation-sensitive component (14), and an oil channel that is arranged to extend between the chamber (12a, 12b) and said cavitation-sensitive component (14). The oil channel comprises a series of restrictions (18) and oil volumes (20) to hinder the movement of cavitation bubbles through said oil channel.

Abstract: A driver (3) for the transfer of torque and rotation from a rotation chuck (5) to a drill steel (2), whereby the cross-section of the driver (3) is limited outwards by curves, in particular by arcs, united to form a closed FIG. 6 that can be approximately described as a polygon, and limited inwards by splines (4). The FIG. 6 comprises four sides (7) and four corners (8). The splines (4) comprise a number of spline teeth (10), the number of which is divisible by four.

Abstract: A device for a flushing head (3) of a rock drilling machine (1), which includes a machine housing (3) and, inside a cylinder (18), a to and fro moveable percussive piston (17) arranged to exert percussive action against a shank adapter (15), wherein the shank adapter has symmetry axis (19) and a flushing medium channel (22,23) for co-operation with a flushing medium chamber (24) in the flushing head (3) surrounding the shank adapter (15), said flushing head (3) being provided with a connection unit (7) for the connection to a flushing hose (10). The flushing head (3) and the machine housing (2) exhibit co-operating fastening means and fastening elements (6) in line with a force direction of tensile forces (F) being exerted by the flushing medium hose (10) on the connection unit (7) for movability of the flushing head (3) in respect of the machine housing (2) in directions perpendicular to said symmetry axis (19). The device also concerns a rock drilling machine including such a device.

Abstract: The present invention relates to a percussion rock drilling machine comprising a front head (1), in which front head (1) are arranged a flush housing (26) and a flush connector (25) for flushing medium. According to the invention, a sheath (31) of rust-resistant material is arranged at the front head (1) around the flush housing (26), such that flushing medium can enter the flush housing (26) through the flush connector (25), without coming into contact with the front head (1).

Abstract: Arrangement (10) for a rock grouting equipment for positioning at least one cartridge (11) is described. The arrangement incorporates at least one magazine (12), arranged around an axis (15). The magazine (12) incorporates at least one space (13), in which space (13) a plurality of said cartridges (11) is stored. The arrangement further incorporates at least one, radially extending, catching device (3, 14), arranged and formed such that it catches at least one cartridge (11) between itself and the inner surface (4) of the magazine body (12), when it performs a rotating movement around the axis (15). The invention also relates to a method.

Abstract: Herein a bolt (2) comprising an elongated body (4) with a central axis (C) is described. The elongated body (4) is in a first end (6) provided with a first thread (8) and in a second end (10) with a second thread (12). An intermediate part (14) of the elongated body (4) is provided with a collar (16). The collar (16) is provided with at least one first flat surface (18), which first flat surface (18) extends substantially in parallel with the central axis (C). Further, a rock drill comprising housing parts held together by at least one bolt (2) is described.

Abstract: The invention relates to a method pertaining to a bolting configuration (299) where a drilling unit and a bolting unit are arranged to be supported by a bottom carriage (330) via a respective top carriage (271; 272), wherein said bottom carriage (330) is arranged to be supported by a feed beam (230), relative to which said bottom carriage (330) is displaceable, wherein said top carriages (271; 272) are arranged to alternately be supported by said bottom carriage (330) to alternately be brought into operative engagement and hereby alternately be locked relative to said bottom carriage (330).