ROCK-CRUSHING HARD-ALLOY INSERT Russian patent published in 1997 - IPC

FIELD: mining industry. SUBSTANCE: such inserts are used for reinforcement of drill bits. Insert is made with adapter cone, and relation of angles α and b of insert working head sharpening formed respectively by tapered and wedge-like surfaces is in range of a/β = 0.70-1.40. Radius R of blunting of working head wedge-like surface is related to insert tail diameter d as follows: R/d = 0.2-0.35. Blade of insert has rectilinear middle part and two curved side sections. Radius of curvature of aforesaid sections is less than length of rectilinear middle part. Height h of working head is related to tail diameter as follows: h/d = 0.45-0.75. This design optimizes changing of insert stressed-deformed state during operation of system "tool-rock" for higher wear-resistance of insert due to less concentration of stresses in it. EFFECT: high efficiency. 3 dwg