Patent ID: 8069917

Claim:
An elongated tool for use within an elongated passage, comprising a gripper assembly for anchoring the tool within the passage, the gripper assembly comprising: a plurality of elongated flexible gripper portions each having ends secured to and rotatable with respect to elements of the tool; a slider element that is longitudinally movable with respect to the gripper portions; a plurality of links each having a first end and a second end, the first end of each link having a substantially constant radial position and being rotatably engaged with respect to the slider element, the second end of each link having a variable radial position and being rotatably engaged with respect to one of the gripper portions; and an actuation assembly configured to urge the slider element longitudinally with respect to the gripper portions, the actuation assembly permitting selective urging of the slider element in a first direction and in a second direction opposite the first direction; wherein: the gripper assembly has a movement-limiting mode configured to substantially prevent relative longitudinal movement between the gripper portions and the passage, the gripper assembly also having a movement-permissive mode configured to permit relative longitudinal movement between the gripper portions and the passage; urging the slider element in the first direction relative to the gripper portions causes the gripper assembly to be in the movement-limiting mode; and urging the slider element in the second direction relative to the gripper portions causes the gripper assembly to be in the movement-permissive mode.