Patent ID: 6533050
Filing Date: 2003-03-18
Classification: E21B

Abstract:
An excavation bit for attachment to a drill rod comprising:a main body having a rotational axis which is coaxial with a longitudinal axis of the drill rod when connected to said bit; at least one carrier rotatably connected to said main body and having a means for excavating positioned about its periphery, each carrier having an axis of rotation at an angle to the main body rotational axis when said carrier is viewed from its front or rear, the axis of rotation including a lateral offset from the main body rotational axis so that the axis of rotation of each carrier does not intersect with the main body rotational axis, the angle being such as to locate said excavation means at or near to the longitudinal axis at a location away from said main body in a direction of excavation when in use, said at least one carrier having a rotation direction opposite to the rotation direction of the main body when said rotation directions are viewed along the direction of the longitudinal axis when said excavation bit is in use.