DRILL BIT Russian patent published in 2001 - IPC

FIELD: drilling equipment. SUBSTANCE: invention refers to cone drill bits with valve units which are simple and reliable in operation. Valve unit is made of body and two spring-loaded working flaps with bevels of reverse orientation on contact surface. Both flaps are pressed tight one against another and to flat ring of body when supply of working agent is stopped to ensure reliable sealing. Flap loaded with spring of high compression effort and having acute bevel angle in upper part closes first, after it flap loaded with spring of lesser compression effort and having bevel angle of contact surface of opposite orientation closes next. With restoration of air supply both flaps turn about their axes opening access of air into blow-through conduits and into cooling ducts of supports providing for biggest area for passage of air. There is practically no loss of air thanks to pressure difference above and under valve. Drill bit with simple and reliable valve unit ensures abrupt increase of driving per drill bit and of mechanical velocity of drilling. EFFECT: abrupt increase of driving per drill bit. 3 cl, 1 dwg