INSTRUMENT FOR BORING OBJECT Russian patent published in 2009 - IPC E21B7/18 

FIELD: mining.

SUBSTANCE: present invention pertains to a boring instrument, particularly to a water jet apparatus for bore-hole drilling. The instrument has a water jet system, meant for applying onto the bored object, a stream of boring fluid, mixed with abrasive particles. The water jet system has a nozzle device, designed for admitting fluid and abrasive particles through the inlet opening and releasing jets of fluid, mixed with abrasive particles. The water jet system of the instrument is meant for circulating abrasive particles from the returning current of boring fluid back into the jet system. Along the path of the hydraulic returning current with an inlet opening, there is a filtering device for keeping the inlet opening of abrasive particles free from objects with the same size as the inlet opening, or larger. This filtering device allows abrasive particles to pass through.

EFFECT: increased efficiency of the boring instrument.

9 cl, 7 dwg, 1 tbl