DRILLING ASSEMBLY Russian patent published in 2010 - IPC E21B4/14 

FIELD: mining.

SUBSTANCE: drilling assembly includes housing with HP chamber and channels in which air hammers are located, each of which has a cylinder, in central hole of which there installed is a valve with longitudinal through holes and a stem, a hammer head and a drilling bit installed with possibility of axial movement and having the shape of a piston with a stock, and central blind holes. Channels are made at an angle of (3-5)° to rotation axis of drilling assembly, housing is equipped with a patch piece with grooves, which is fixed at the end and placed in lower part of each of the channels with a journal box with a flange located between housing and patch piece so that the cavity attached to grooves of the patch piece is formed, from the side of which along the housing axis there made is a blind hole. Central hole of cylinder has different diametres throughout its length; piston of hammer head which contacts larger diametre of central hole of cylinder is equipped with two inclined holes the axes of which cross the axis of its central blind hole, and the pin fixed at its lower edge part; diametre of piston of drilling bit corresponds to diametre of channel, and its stock is placed in a journal box and has vertical slots made in the half of its length and ending with drilled side holes crossing the central blind hole of drilling bit.

EFFECT: increasing intensity of breaking process of hard rocks.

2 dwg