Patent ID: 7658241

Claim:
A drilling tool, comprising: a tubular body defining a longitudinal axial cavity extending therethrough; the tubular body also defining at least one radial guidance channel extending radially from the axial cavity through the tubular body; a cutter element disposed in the at least one radial guidance channel; the cutter element including an internal surface inclined at an angle to a longitudinal axis of the tubular body; a wedge element having an external surface configured to engage the internal surface of the cutter element and to direct the cutter element from a retracted position to an extended position as the wedge element moves from a first position to a second position; a drive pipe disposed within the axial cavity, the drive pipe being configured to be removably coupled with the wedge element and to allow removal of the drive pipe from within the axial cavity independently of the wedge element; and wherein: the drive pipe is coupled to the wedge element and configured to move the wedge element from the first position to the second position as the drive pipe moves from a first longitudinal position to a second longitudinal position; the drive pipe defines a longitudinal slot along an intermediate portion of the drive pipe and a peripheral slot disposed adjacent a first end of the longitudinal slot; the drive pipe is configured to permit the wedge element to slide within the longitudinal slot when the drive pipe is in a first angular position; and the drive pipe is configured to fixedly couple the wedge element to the peripheral slot of the drive pipe as the drive pipe is rotated from the first angular position to a second angular position.