SHANK ADAPTOR WITH FRACTURE RESISTANT FLUSHING HOLE

摘要

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.

主权项

1. A rock drilling shank adaptor comprising:
an elongate body having a first end to be positioned towards a piston and a second end to be positioned towards a drill string, the body including an axially extending internal bore to allow passage of a flushing fluid to the drill string via the second end; and a flush hole extending radially through the body to the internal bore, the hole defined at an external side by an edge having an axially forward region positioned closer to the second end than an axially rearward region positioned closer to the first end, wherein the forwardmost and rearwardmost regions of the edge include straight sections, each straight section being bordered at each end by a respective curved section.