DIAMOND CROWN BIT Russian patent published in 2003 - IPC

FIELD: rock breaking tools. SUBSTANCE: invention is related to diamond crown bits with core sampling. Objective of invention lies in design of crown bit structure securing high efficiency of drilling with lesser energy consumption and improved conditions for core formation. Given diamond crown bit has body carrying diamond-containing matrix divided into hole-forming and core- forming sectors displaced along radius and height and arranged in staggered order with formation of hydraulic chambers matched with washing grooves. Core-forming sectors are height-advanced with reference to hole-forming sectors and are separated one from another by washing grooves possessing side walls of different height. Hydraulic chambers are conjugate to grooves lying nearby along circumference and communicates with them. EFFECT: diminished energy consumption in process of drilling by way of reduction of contact area of working surface of matrix with rock, isolation of core from outside mechanical effects from walls of hole and slurry. 2 dwg