Patent ID: 7934568
Filing Date: 2011-05-03
Classification: E21B

Abstract:
1. A core removal apparatus for removing the core from a substrate, comprising: a drill tube having a driving end and an attachment end, the driving end being adapted to accept an external driving means, a drill bit coaxially attached to the attachment end of the drill tube and being capable of drilling a core of the substrate and having an inner lip at a drilling end, a ground tube disposed coaxially within the drill tube and drill bit and having a driving end and a collecting end, a collet tube disposed coaxially within and being rotationally coupled but not axially coupled to the ground tube and having a driving end and a collecting end, an ejection rod located coaxially within the collet tube adapted to move axially within the collet tube, and a driving system engaging the ground tube and collet tube, comprising: