DRILLING ROLLER BIT Russian patent published in 2000 - IPC

FIELD: rock crushing tools. SUBSTANCE: roller bit is intended for drilling bore-holes of large diameter. Roller bit has body with connecting thread, washing passages, and slots in external surface. Rigidly secured in body slots are legs with rolling cutters. Connecting thread of body is made in the form of threaded nipple. Diameter of larger base of nipple relates to external diameter of drilling bit by following ratio: d/D = 0.3-0.6, where d - diameter of larger base of tapered nipple; D - external diameter of drilling bit. Aforesaid embodiment of drilling bit allows for simplifying technology of its manufacture with simultaneous reduction of metal input and cost. EFFECT: higher efficiency. 1 dwg