| 摘要 |
An apparatus and method for forming a borehole in an earthen formation includes a side cutting device comprised of a cam assembly that includes at least one groove therein for selective extension and retraction of a laterally extending cutting element. Rotation of the side cutting device in a first direction causes the cutting element to be in a first retracted position so that a borehole having a first diameter can be formed. Rotation of the side cutting device in a second direction causes the cutting element to be in a second extended position. Rotation and retraction of the side cutting device when the cutting element is in the second extended position allows the side cutting device to create a larger borehole diameter in a down hole location. |
