DOWNHOLE PNEUMATIC HAMMER Russian patent published in 2000 - IPC

FIELD: hole drilling. SUBSTANCE: downhole pneumatic hammer has inlet and outlet channels in longitudinal recesses of body located inside sleeve. Made in longitudinal protrusions between recesses are additional longitudinal recesses semicircular in cross-section with chord chamfer towards outlet channels. Flexible cord is located in these recesses with interference fit for sealing of inlet recesses. Exhaust channel is communicated with side longitudinal channels of bit. Rotary motion is transmitted to bit through bushing with the help of embedded members which length does not exceed value of interlocking stroke of bit. EFFECT: higher operating reliability and hammering power. 3 dwg