| abstract |
A gripper assembly 100 is for anchoring a tractor within a downhole passage and for assisting movement of the tractor within the passage. The gripper assembly 100 includes an elongated mandrel 102 and flexible toes 112 that can be radially displaced to grip onto the surface of the passage. The toes 112 are displaced by the interaction of a driver slidable on the mandrel and a driver interaction element on the toes 112. In one embodiment, the toes 112 are displaced by th interaction of rollers 132 and ramps 126 that are longitudinally movable with respect to one another. In another embodiment, the toes 112 are displaced by the interaction of toggles 180 that rotate with respect to the toes 112. |