Patent ID: 7624808
Filing Date: 2009-12-01
Classification: E21B

Abstract:
1. A gripper assembly having an actuated position in which said gripper assembly substantially prevents movement between said gripper assembly and an inner surface of a passage, and a retracted position in which said gripper assembly permits substantially free relative movement between said gripper assembly and said inner surface of said passage, said gripper assembly comprising: an actuator configured to selectively move the gripper assembly between the actuated position and the retracted position; an expandable assembly comprising a plurality of segments pivotally connected in series, the expandable assembly coupled to the actuator such that the expandable assembly is selectively moveable between a retracted position in which a longitudinal axis of the expandable assembly is substantially parallel with an elongated shaft along which the gripper assembly is moveable and an expanded position in which the segments of the expandable assembly are buckled radially outward with respect to the elongated shaft; a toe having a first end, a second end, and a central area, the first and second ends being pivotally coupled to the elongated shaft such that the first and second ends maintain an at least substantially constant radial position with respect to a longitudinal axis of the elongated shaft, and the central area being radially expandable with respect to the elongated shaft such that an expanded position of the toe corresponds to the actuated position of the gripper assembly and a retracted position of the toe corresponds to the retracted position of the gripper assembly; a roller mechanism rotatably coupled to an inner surface of the central area of the toe, the roller mechanism configured to interface with an outer surface of one of the plurality of segments of the expandable assembly such that as the expandable assembly is buckled by the actuator, the roller mechanism is advanced up the one of the plurality of segments and the toe is expanded.