Patent ID: 8172009

Claim:
An expandable tool for an earth boring system, comprising; a mandrel comprising a tubular body with an outer surface; a sleeve is positioned around the outer surface and comprises a blade disposed in a slot formed in the thickness of the sleeve; the sleeve is also configured to slide axially along a length of the tubular body; the blade comprises an interior slide groove located on an interior blade surface and an exterior slide groove located on an exterior blade surface; a sleeve protrusion of the sleeve is configured to extend into the interior slide groove, a mandrel protrusion of the outer surface of the mandrel is configured to extend into the exterior slide groove; the blade is configured to shift laterally out of the slot as the sleeve slides axially; wherein the interior and exterior slide grooves are oriented at different angles and as the sleeve slides axially along the length of the mandrel, the slide grooves lock the blade in a pre-determined position through a wedging effect.