ELECTRIC PULSE DRILLING ASSEMBLY Russian patent published in 2013 - IPC E21B7/15 E21C37/18 

FIELD: mining.

SUBSTANCE: hydraulic current lead (1), drill stem (2) and drill head including housing (6), high-voltage and earthed electrodes (7 and 8) and high-voltage insulator (9) are connected in series in the assembly. Inside drill stem (2) there coaxially fixed is axial current lead (5), on which central pipe (10) is freely put and provided with charging device (14) and high-voltage pulse (15) source, which are fixed on the above central pipe. Shock absorbing spring (12) is installed under high-voltage pulse (15) source in casing (13) freely put on central pipe (10). One or more bottom-hole posts (11) are attached to lower end of central pipe (10) and have the possibility of longitudinal movement till they come out of the drill head by more than 1/3 of inter-electrode distance.

EFFECT: period of trouble-free operation of a charging device and a high-voltage pulse source is increased by several times.

3 cl, 3 dwg, 1 ex