CIRCULAR AIR HAMMER Russian patent published in 1996 - IPC

FIELD: mining, particular, devices for hole drilling applicable in mining, hydrogeology and geological prospecting. SUBSTANCE: circular air hammer includes percussive mechanism with exhaust channel towards hole bottom, drilling cuttings transportation pipe, and drilling tool with central channel for receiving drilling cuttings and having receiving and mixing chambers separated by partition with central hole. Diameter of partition central hole, inner diameter of drilling cuttings transportation pipe and parameters of mixing chamber are taken from the relations d_n≅ d_t = (0.4-0.5)D, L= (1.2-1.5)D, where d_n is diameter of partition central hole; d_t is inner diameter of drilling cuttings transportation pipe; D and L are diameter and length of mixing chamber. Besides, mixing chamber is communicated with exhaust passage by means of channels, and partition has radial recesses also communicated with exhaust passage by means of channels. EFFECT: extended technological capabilities due to drilling, practically, any type of rocks under normal technogenic conditions. 3 cl, 3 dwg