ROLLER REAMER Russian patent published in 1998 - IPC

FIELD: bore-hole drilling machinery and equipment. SUBSTANCE: this roller-bit reamer is used for reaming bore-holes primarily in middle-hard and soft rock. Reamer has body with longitudinal slots, and seated and secured in these slots by means of axles and shells are roller bits with rims. Lower rock crushing rim is provided with larger number of teeth than adjacent calibrating rim. Plane of symmetry of lower rim coincides with longitudinal axis of roller bit, and adjacent rim has its plane of symmetry of teeth displaced in parallel to roller bit axle. Axle is fastened with roller bit by means of pins and is locked from axial displacement relative to shell by means of nut. Shell is rigidly secured to body through strips and is provided with hard-alloy inserts at side of bore-hole wall. Bottom hole is cleared from sludge with the help of drilling fluid which is delivered through hydraulic pressure units located in pipe unions between roller bits. Reamer can be used individually or together with pilot drill bit. Aforesaid embodiment makes operation of roller reamer more effective. EFFECT: higher efficiency. 3 cl, 4 dwg