CONE DRILL BIT Russian patent published in 2002 - IPC

FIELD: drilling equipment. SUBSTANCE: valve unit of cone drill bit is rather simple in design and reliable in operation. Non-return valves placed in blow-through ducts of drill bit include valve nozzles with seats and working element in the form of butterfly spring-loaded gate with attachment unit. Butterfly gate is mounted on outside of separable beveled packing, its attachment unit being located by upper edge of beveled lower face of packing. Possibility of fast replacement of packing in the field makes it possible to establish pressure and direction of jet of clearing agent optimal for specific drilling conditions. Since lower face of packing has bevel of 25-50 degrees it is feasible to decrease angle of flanging of spring considerably and to diminish operation time of valve which consequently reduces non- productive losses of pressure of working fluid in system of face blow-through. EFFECT: raised drilling per cone drill bit and speed of drilling. 3 cl, 4 dwg