SHANK ADAPTER WITH REINFORCED FLUSHING HOLE Russian patent published in 2019 - IPC E21B17/03 

FIELD: soil or rock drilling; mining.

SUBSTANCE: group of inventions relates to percussion drilling. Device for drilling of rock contains shank end adapter. Adapter comprises an elongated body, the first end of which is located in the direction of the piston, and the second end is in the direction of the drill string, wherein said housing comprises axially extending inner channel to allow passage of flushing fluid to drill string via second end, flushing hole extending radially through said case to inner channel. Flushing hole has axially front zone located closer to second end than axially rear zone located closer to first end, and has a radially outer side located on the outer surface of the adapter, as well as a radially inner side located on the inner channel, wherein outer and inner sides are connected by means of mainly radially passing surface, which forms flushing hole passing through housing. Flushing hole in axially rear zone is reinforced relative to axial front zone by that in radial direction from outer side to inner side surface in rear zone at least on radial inner section is curvilinear or arranged transversally relative to the innermost radial portion of the opening surface in the axial front zone in the radial direction such that the back surface area on the inner side is located axially closer to the second end than the rear surface area on the outer side.

EFFECT: technical result is minimization or elimination of probability of destruction of adapter wall by crack propagating from flushing hole.

15 cl, 4 dwg