Abstract: A drill body and a drill are disclosed. The drill body has a rotational axis and comprises a central chip flute extending along a periphery of the drill body. A central chip flute cross-section has a centre line extending in a plane extending perpendicularly to the rotational axis, and through the rotational axis. The central chip flute cross-section has a depth, as seen along the centre line, and a width as seen perpendicularly to the centre line. The central chip flute cross-section has a maximum depth Dp within a range of Dp=0.75×D/2 to Dp=0.90×D/2, and a maximum width W within a range of W=0.75×D/2 to W=0.90×D/2, and wherein the maximum width W extends symmetrically about the centre line.

Abstract: A drill body and a drill are disclosed. The drill body has a rotational axis and includes a peripheral chip flute extending along a periphery of the drill body. A peripheral chip flute cross-section has a centre line extending in a plane extending perpendicularly to the rotational axis, and through the rotational axis. The peripheral chip flute cross-section has a radially inner side extending perpendicularly to the centre line, and first and second lateral sides connecting to the radially inner side. The radially inner side has a length L1 within a range of L1=0.95×D/4 to L1=1.2×D/4. Each of the first and second lateral sides has a length LS1, LS2 within a range of D/4 to 1.3×D/4. The first and second lateral sides diverge from each other in a direction radially outwards from the radially inner side.

Abstract: A drill body and a drill are disclosed. The drill body has a rotational axis and comprises a central chip flute extending along a periphery of the drill body. A central chip flute cross-section has a centre line extending in a plane extending perpendicularly to the rotational axis, and through the rotational axis. The central chip flute cross-section has a depth, as seen along the centre line, and a width as seen perpendicularly to the centre line. The central chip flute cross-section has a maximum depth Dp within a range of Dp=0.75×D/2 to Dp=0.90×D/2, and a maximum width W within a range of W=0.75×D/2 to W=0.90×D/2, and wherein the maximum width W extends symmetrically about the centre line.

Abstract: A drill body and a drill are disclosed. The drill body has a rotational axis and includes a peripheral chip flute extending along a periphery of the drill body. A peripheral chip flute cross-section has a centre line extending in a plane extending perpendicularly to the rotational axis, and through the rotational axis. The peripheral chip flute cross-section has a radially inner side extending perpendicularly to the centre line, and first and second lateral sides connecting to the radially inner side. The radially inner side has a length L1 within a range of L1=0.95×D/4 to L1=1.2×D/4. Each of the first and second lateral sides has a length LS1, LS2 within a range of D/4 to 1.3×D/4. The first and second lateral sides diverge from each other in a direction radially outwards from the radially inner side.

Abstract: A rock drill bit includes a head provided at one end of an elongate shank. A plurality of fluid flushing passageways extend axially from an internal bore extending through the shank with at least one fluid flushing passageway having an exit end at the front face formed as an elongate slot having a length greater than a width to facilitate the rearward transport of cut rock fragment.

Abstract: A rock drilling shank adaptor has at least one flush hole extending radially through the body of the adaptor in communication with an axially extending internal bore. The flush hole in a direction from an external side to an internal side includes a surface at a rearward region that is curved at least at a radially inner portion to extend in an axial direction towards a forwardmost end of the adaptor to increase the resistance of the adaptor to stress concentrations whilst achieving a desired flow rate of flushing fluid flow into the internal bore.

Abstract: A rock drilling shank adaptor has at least one flush hole extending radially through the body of the adaptor in communication with an axially extending internal bore. The flush hole in a direction from an external side to an internal side includes a surface at a rearward region that is curved at least at a radially inner portion to extend in an axial direction towards a forwardmost end of the adaptor to increase the resistance of the adaptor to stress concentrations whilst achieving a desired flow rate of flushing fluid flow into the internal bore.

Abstract: A rock drill bit includes a head provided at one end of an elongate shank. A plurality of fluid flushing passageways extend axially from an internal bore extending through the shank with at least one fluid flushing passageway having an exit end at the front face formed as an elongate slot having a length greater than a width to facilitate the rearward transport of cut rock fragment.

Abstract: A percussive rock drill bit includes a head provided with an elongate shank. A plurality of front cutting inserts are distributed at a front face of the head and are grouped into a plurality of sets, with each set being positioned at a different radial distance from a central axis. Each set of inserts includes the same number of inserts to maximize drilling rate and service lifetime of the drill bit.

Abstract: A rock drilling shank adaptor includes an elongate body having an internal flushing bore and an entry hole through the sidewall of the adaptor in fluid communication with the internal bore. The flushing hole is optimized to reduce the likelihood of fracture at the wall of the adaptor and in particular includes straight sections at axially forward and rearwardmost regions of the hole.

Abstract: A rock drilling shank adaptor includes an elongate body having an internal flushing bore and an entry hole through the sidewall of the adaptor in fluid communication with the internal bore. The flushing hole is optimised to reduce the likelihood of fracture at the wall of the adaptor and in particular includes straight sections at axially forward and rearwardmost regions of the hole.

Abstract: A rock drill bit for percussive drilling comprising a bit head configured to be attached at an end of a drill element of a drilling assembly and having a diameter larger than that of a said drill element. The bit head has at a front end as seen in the intended drilling direction a generally frusto-conical shape defined by a substantially circumferential ring provided with a plurality of gauge buttons distributed along the extension of the ring for engaging material to be crushed. A central flush channel extends through the bit head and has at least one flushing hole opening at said front end to conduct flushing medium to said front end. At least one peripheral flushing hole of said at least one flushing hole opening at said front end opens in said substantially circumferential ring. At least two peripheral flushing holes open in said substantially circumferential ring.

Abstract: A rock drill bit for percussive drilling comprising a bit head configured to be attached at an end of a drill element of a drilling assembly and having a diameter larger than that of a said drill element. The bit head has at a front end as seen in the intended drilling direction a generally frusto-conical shape defined by a substantially circumferential ring provided with a plurality of gauge buttons distributed along the extension of the ring for engaging material to be crushed. A central flush channel extends through the bit head and has at least one flushing hole opening at said front end to conduct flushing medium to said front end. At least one peripheral flushing hole of said at least one flushing hole opening at said front end opens in said substantially circumferential ring. At least two peripheral flushing holes open in said substantially circumferential ring.