MINING DRILL BIT

摘要

An improved roof drill bit for use in mining operations in which a carbide insert is diametrically located in a cylindrical body and held on axial prongs in diametrically opposed quadrants of the body by a brazed connection; diverging axial holes for coolant are positioned in said prongs to open at the trailing side of the cutting edges of the carbide insert to flood the edges with coolant liquid and flush cuttings into the other quadrants. The coolant passages also pass near the brazed face of the insert to cool the body in this area and minimize softening of the braze. i.