Core drilling apparatus and method for converting between a core drilling assembly and a full-diameter drilling assembly

摘要

A core drilling apparatus and a method for converting between a core drilling assembly and a full-diameter drilling assembly by means of a lifting device and a coring drill head with closure elements and integrated cutting implements. The lifting device comprises a release mechanism that when activated, releases forces acting on the lifting device, such that when the lifting device is in an upper position when activated, the lifting device lowers an inner tubing thereby pushing the closure elements of the drill head in an open position, and when the lifting device is in a lower position when activated, the lifting device lifts the inner tubing from the closure elements such that the closure elements is in a closed or partly closed position.