摘要 |
FIELD: mining. ^ SUBSTANCE: expanding reamer includes tubular housing, at least one blade each of which is connected by position to inclined guide of tubular housing, pushing sleeve and movable sleeve. Each blade includes at least one cutting element. Pushing sleeve is located in inner channel of tubular housing and connected to each blade so that it causes their axial movement along guides to extended position at action of force and pressure of drilling fluid when it passes via its passage in inner channel. Guide is inclined upwards at an acute angle. Movable sleeve is made so that it can isolate pushing sleeve and blade randomly against drilling fluid pressure. At that, upward movement of movable sleeve makes pushing sleeve movement possible under drilling fluid pressure. ^ EFFECT: improvement of device operating reliability. ^ 18 cl, 26 dwg |