Patent ID: 6640894
Filing Date: 2003-11-04
Classification: E21B

Abstract:
A gripper assembly for anchoring a tool within a passage, said gripper assembly having an actuated position in which said gripper assembly substantially prevents movement between said gripper assembly and an inner surface of said 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 elongated mandrel configured to be engaged with respect to said tool; a first toe support longitudinally fixed with respect to said mandrel; a second toe support longitudinally slidable with respect to said mandrel; a flexible elongated toe having a first end pivotally secured with respect to said first toe support and a second end pivotally secured with respect to said second toe support so that said first and second ends of said toe have an at least substantially constant radial position with respect to a longitudinal axis of said mandrel; a driver longitudinally slidable with respect to said mandrel, said driver being longitudinally slidable between a retraction position and an actuation position; and a driver interaction element on a central region of said toe, configured to interact with said driver; wherein longitudinal movement of said driver causes interaction between said driver and said driver interaction element substantially without sliding friction therebetween, said interaction varying the radial position of said central region of said toe, wherein when said driver is in said retraction position said central region of said toe is at a first radial distance from said longitudinal axis of said mandrel and said gripper assembly is in said retracted position, and when said driver is in said actuation position said central region of said toe is at a second radial distance from said longitudinal axis and said gripper assembly is in said actuated position.