ELECTRIC-PULSE NON-ROTATING DRILL BIT Russian patent published in 2016 - IPC E21B7/15 E21C37/18 E21B10/00 

FIELD: mining.

SUBSTANCE: invention is intended for drilling column wells and wells without core sampling with back inner flushing in hard rock, and can be used during exploration works, in mining industry, in construction works. Coaxial assemblies of external (2, 3) and internal (4, 5) drilling crowns are divided by high-voltage insulator (1). Drilling bit body (2) is connected to drill string (6), and core adapter (4) is connected to high-voltage current lead (7). Internal crown (5) is spring-loaded by spring (11), with possibility of advancing external crown (3) not more than by 1/3 of inter-electrode distance. Along inner surface of internal crown (5) there are tangentially located blades of hard-alloy cutters (16), shaped as one-sided wedges, and along outer surface of external crown (3) there are blades of similar cutters (17). Inner electrode ribs (14) of external crown (3) and outer electrode ribs (15) of internal crown (5) are made with multifaceted hard-alloy cutters (18, 19), which enable to align bottom hole.

EFFECT: hard-alloy cutters in form of one-sided wedge (16, 17), can prevent sticking of drilling bit on cores and well walls.

3 cl, 3 dwg