Patent ID: 8770323

Claim:
An apparatus for forming a borehole in an earthen formation, comprising: a side cutting assembly comprising; a first body portion having a first end configured for coupling to a drill bit and a central vacuum bore; a second body portion coupled to the first body portion having a second end configured for coupling to a drill stem; one of the first body portion and second body portion having a nonconcentric cylindrical portion with a diameter that is less than a diameter of the first body portion proximate the first end; a sleeve disposed on the nonconcentric cylindrical portion and being partially rotatable relative thereto between a first position and a second position; at least one cutting element disposed on the sleeve so that when the sleeve is in the first position, the at least one cutting element is in a retracted position and when the sleeve is in the second position the at least one cutting element is in an extended position for cutting a sidewall of a borehole to enlarge a diameter of the borehole while the at least one cutting element is in the extended position, the at least one cutting element having a leading edge that is spaced radially farther from the longitudinal axis of the first body when the at least one cutting element is in the extended position and wherein the at least one cutting element engages a sidewall of a borehole when rotation of the drill bit is reversed.