SETT ATT DRAGA UT EN BORRKRONA UR ETT BORRHAL

摘要

A drilling system includes a drill pipe and a cutting means located therein. A locking mechanism with said drill pipe is provided on said cutting means and is operatively connected with a spearhead engageable with an engaging mechanism of a pulling-up device so that, when the spearhead is pulled, an inner tube and outer tube forming a part of the locking mechanism may move relative to each other to unlock the drill pipe and cutting means for quickly and easily pulling up the latter.