EXPANDING REAMER FOR HOLES REAMING AND METHOD OF HOLE REAMING

摘要

FIELD: mining.;SUBSTANCE: expanding reamer contains outer housing (16) with through channel (17) for fluid medium and at least one blade (40). The blade is designed with possibility to move against the housing between retracted position and extended position towards housing longitudinal axis at an acute angle. In addition the reamer contains inner moving tubular member (30) designed with possibility to move between the first and the second position when hydraulic pressure difference between various parts of channel for fluid medium reaches preset value. Sizes and form of the blade provide a gap over 0.254 mm between the housing and each side surface of the blade. The blade includes the main part (46) with inclined surface (47) at the first angle to the housing axis which may be jammed against the housing inclined surface (60) at the second angle, different from the first angle, against longitudinal axis.;EFFECT: improving reliability of the device operation during drilling, avoiding damages during round-trip operations.;18 cl, 15 dwg