ROLLER-CUTTER DRILLING BIT Russian patent published in 2002 - IPC

FIELD: roller-cutter drilling bits designed for well compressed-air or air-water mixture drilling in mining industry. SUBSTANCE: roller-cutter drilling bit has a built-in check valve whose cylindrical body has inlet windows. The check valve is connected with bit jet nozzle and covered from atop with cover having axial hole. Located inside the body is a distributor of flow of a blowing-flushing agent pressed to the cover by spring and made of two parts, one of which - upper part is uniform of cylindrical overturned sleeve, and the other part, in the form of a tube. Parts are interconnected by the central rod and located from each other at a distance equalling sum of inlet window and belt covering it by tubular part in idle position of the valve. EFFECT: reduced losses of pressure of blowing-flushing agent in cleaning of well, higher operating reliability. 1 dwg