Patent ID: 9447648
Filing Date: 2016-09-20
CPC Classification: E21B

Claim Text:
1. A gripper assembly comprising: a link mechanism comprising a tension link having a first end and a second end, said tension link connected to a first and a second lift link; said first lift link pivotably connected to said tension link at said second end; said second lift link pivotably connected to said tension link at said second end so as not to be translatable between the first end and the second end of the tension link; said first and second lift links slidably attached to an elongate body; a roller disposed on an end of said first lift link; a slot disposed in said tension link adjacent the pivotable connection of the second lift link and the tension link, said slot comprising a first end and a second end opposite said first end, said first lift link translatable along said slot between the first end and the second end of the slot; and an expansion surface upon which said roller acts to provide an expansion force; wherein for a first expansion range the movement of the roller upon the expansion surface expands the linkage; for a second expansion range the movement of the first lift link pushing against the second end of the slot expands the linkage; and for a third expansion range the movement of the second lift link expands the linkage.