ELECTRIC PULSE DRILL HEAD Russian patent published in 2011 - IPC E21B7/15 E21C37/18 

FIELD: mining.

SUBSTANCE: electric pulse drill head consists of high-voltage and earthed electrode systems separated with insulator (1) having central flushing port (2); electrodes (7 and 15) of the above systems are pin-type, which alternate and are uniformly located in circumferential direction. High-voltage electrode system is equipped with hollow central electrode (4 and 5). Drill head is also equipped with additional earthed electrode (16) which is annular and installed in end face part of earthed electrode system, and it is connected to electrodes of the above system (15) by means of earthed connection straps (17).

EFFECT: uniform destruction of the working face without reducing the drilling efficiency.

3 cl, 6 dwg, 3 ex