CIRCUIT AIR HAMMER FOR HOLE DRILLING Russian patent published in 1994 - IPC

FIELD: equipment for geological exploration, mining and construction. SUBSTANCE: air hammer has body consisting of cylinder 1 and sleeve 2, stepped air hammer 3, air distribution pipe 4, core-cuttings receiver 5, nut 6, rock cutting tool 7, upper bushing 10, lower bushing 8 and distributing bushing 9, and locking ring 13. Compressed air is supplied to air inlet duct 14 of air hammer through annular gap between barrels 11 and 12 of double core barrel string. Rated amount of compressed air is fed to inner barrel 11 of double core barrel string to create zone of low pressure. Main part of compressed air performs starting of air hammer through channel 16. Rock cutting are entrained by flow of exhaust air and due to locking ring 13 and rush into zone of low pressure. When passing channel 15, cuttings mixture is imparted additional speed momentum due to energy of air jet and directed to surface through inner barrel of double core barrel string. When air hammer is withdrawn from hole bottom, air from air line acts on hole bottom thus additionally cleaning it of cuttings. EFFECT: higher efficiency. 2 cl, 1 dwg