Patent ID: 7748476

Claim:
A gripper assembly comprising an elongate body having a length along a first axis; a linkage configured to be radially expanded between a retracted position and an expanded position relative to the elongate body, the linkage comprising a first link having a first end and a second end, and a second link having a first end and a second end, said second end of the first link coupled to the first end of the second link, the first end of the first link slidable with respect to the elongate body, one of the first end of the first link and the second end of the second link forming a base angle relative to the first axis; and an expansion surface slidable with respect to the elongate body; wherein for a first expansion range from a first position to a second position, movement of the first end of the first link relative to the second end of the second link radially expands the linkage, and for a second expansion range a rate of change in the base angle is reduced as the linkage radially expands; and wherein for a third expansion range between the retracted position and the first position, the expansion surface bears on the linkage to radially expand the linkage.