FLUSHING ASSEMBLY OF DRILLING BIT (VERSIONS) Russian patent published in 2015 - IPC E21B10/60 

FIELD: mining.

SUBSTANCE: flushing assembly of a drilling bit includes a housing with a channel and a seat having an annular bore, a head piece with a sealing element and a retaining device arranged in the annular bore of the seat, which are installed in the seat, and a fastening assembly. Difference consists in the fact that the fastening assembly comprises a plate, a latch and a protective casing. When in a working position, a free end of the latch is arranged in the slot of the plate to interact with the side wall of the plate and fixed relative to the plate by means of a screw. The protective casing has an inspection hole at radial distance equal to radial distance to the specified screw, and it is of a cylindrical three-stage type with an internal channel; a stage of larger diameter has a possibility of being borne against the housing surface; a stage of mean diameter has an external thread mating the internal thread in the seat of the flushing assembly, and presses with its end face the plate and the latch to the retaining device and the head piece, and a stage of smaller diameter ends near the end face of the head piece.

EFFECT: improving operating efficiency of a flushing assembly.

2 cl, 6 dwg