CONE DRILL BIT Russian patent published in 2000 - IPC

FIELD: rock breaking tools. SUBSTANCE: invention is related to cone bits designed for drilling with air blow-through. Cone drill bit includes feet with nipple, conduits to cool supports of roller bits and to clean face from slurry and valve boxes located in cleaning ducts. Each valve has body made fast to feet of case whose space houses shutting element and return element. Side walls of body have radial through holes, predominantly, of slit-like shape. Upper part of shutting element has convex form and is used as guide for cleaning agent. Return element is made of elastic material. Upper part of shutting element has section with outer surface corresponding to inner surface of body of valve box in zone of location of return element. Such design of valve unit makes it feasible to prevent slurry from hitting supports of roller bits if supply of cleaning agent is stopped and to enhance operational efficiency of drill bit by this. EFFECT: enhanced operational efficiency 4 cl, 2 dwg of drill bit. 4 cl, 2 dwg