Patent ID: 8347987

Claim:
An apparatus for forming a borehole in an earthen formation having a side cutting assembly comprising; a longitudinally extending body having a first body portion with a first end configured for coupling to a drill bit and a second body portion having a second end configured for coupling to a drill stem, the body having an outer surface defining a first and a second recess each configured for at least partially receiving a side cutting element therein; a first side cutting element at least partially disposed within the first recess, the first side cutting element being movable from a first retracted position within the first recess to a second extended position at least partially extending from the first recess; a second side cutting element at least partially disposed within the second recess, the second side cutting element being movable from a first retracted position within the second recess to a second extended position at least partially extending from the second recess, the first and second cutting elements each have a cutting edge defining a concave cutting surface that is exposed when the respective cutting element is in the second extended position and retracted within the recess when the respective cutting element is in the first retracted position; first and second retaining pins disposed within the first and second recesses, respectively, the first and second cutting elements being rotatably coupled to the first and second retaining pins; whereby rotation of the side cutting assembly in a first direction causes the first and second side cutting elements to be positioned in the first retracted position and rotation of the side cutting assembly in a second opposite direction causes the first and second side cutting elements to be positioned in the second extended position in which the first and second side cutting elements can cut a borehole diameter that is increased to a diameter that is defined by an effective diameter of the first and second side cutting elements in the second extended position.