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 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 down-the-hole hammer drill bit assembly includes a foot valve and a drill component having respective abutment regions in the form of cooperating lugs and shoulders that may be engaged by rotation of the valve relative to the drill bit component to allow the lugs and shoulders to overlap radially to lock the valve at the drill component. The assembly is advantageous to allow coupling and decoupling on-site without the need for specific swaging or hydraulic/pneumatic assembly tools.

Abstract: A down-the-hole hammer drill bit assembly includes a foot valve and a drill component having respective abutment regions in the form of cooperating lugs and shoulders that may be engaged by rotation of the valve relative to the drill bit component to allow the lugs and shoulders to overlap radially to lock the valve at the drill component. The assembly is advantageous to allow coupling and decoupling on-site without the need for specific swaging or hydraulic/pneumatic assembly tools.