Drilling devices and methods for producing undercut holes

摘要

A drilling device (7) for producing undercut holes, said drilling device comprising a drilling tool (2) having an axis of rotation (A) and a cutting portion (6) arranged such that it drills a hole (1) with a longitudinal axis (B) that is radially offset with respect to said axis of rotation and a centering device (9) operable to apply a lateral force to said drilling tool (2) for moving said axis of rotation towards said longitudinal axis to cause said cutting portion to form an undercut (12) in a said hole (1).