Rotary drill bit for earth core drilling - has flexible curved separators attached to opposite inner and outer tube ends

摘要

There are inner and rotating outer core tubes, and core trap device, on the rotating drilling tool for drilling core holes in the ground. Slots (4, 5) to carry the outer tube (3) in the direction of rotation are provided between it and the inner tube (1). Immediately above the drill crown (2) there are one or more transverse flexible dividing media attached at one end (11) to the outer tube and at the other end (10) to the inner tube. These are arranged so that each runs in an arched curve inside an annular space between the drilled core (12) and outer tube, and is extended in a chord shape in the reversed rotation direction. This enables cores of any dia. to be securely separated and lifted from the bottom.