DEVICE FOR HOLE BORING Russian patent published in 2008 - IPC E21B7/28 E21B10/26 

FIELD: mining engineering.

SUBSTANCE: device includes boring column, pilot-chisel, outer tube with massive material destroying changeable aspirails and fixed with pilot-chisel, and hung with key adapter on boring column, inner tube, fixed with boring column, inner and outer leader areas. Key adapter is hung to boring column through the inner tube with ability or limited radial-axial mobility. Inner and outer tubes are fitted with frontal parts for buff load transfer to massive material destroying aspirails and pilot-chisel.

EFFECT: widening of usage sphere, improving of commercial boring speed and durability of material destroying bodies in one and a half-two times.

1 dwg