Patent for an improved, simple, and efficient well sinking or drilling mechanism, especially meant for bit-securing devices, and the drill bits can be easily removed without removing the well tubing from the hole. The inventor uses "a stem or core carrying the drill bit and adapted to fit snugly in the bore of the tubing, together with a simple combination of devices whereby such stem or core can be locked against longitudinal and rotary movement by the manipulation of an operating rod which extends to the top of the well" (lines 16-22).