Tag Archives: Gordon Kirkwood

US Patent #10,710,247 Issued to Kirkwood et al for new Robotic “Conical Iris Gripper”

Overview drawing of the Kirkwoood Conical Iris Gripper
Overview drawing of the Kirkwoood Conical Iris Gripper


I was issued US Patent number 10,710,247 on July 14th 2020 for a new type of robotic gripper device uniquely able to grasp difficult-to-grasp food items.

Robotic preparation of food is hard, in part, because of the difficulty of grasping and manipulating  irregular shaped,  slippery, and loose aggregated cooking ingredients like chopped onions, shrimp, or loose lettuce.    I was asked to consider if any new design could meet the needs of this task, and prototype it.      From my previous work with mechanical iris development inspired by the international space station’s Canadarm gripper,  (see: CNC Bubble Iris), I realized that  a novel 3-degree-of-freedom gripper could meet this need:  a conical cage of slender spears, which could change shape in three different ways:   taper angle,   diameter, and extension.   With these motions, I realized it was possible to make a highly effective gripper with a wide repertoire of potential grasping strategies,   which could allow for a huge range of ingredients to be handled by a single gripper.  The gripper can  either open or close like a hand gathering and grabbing a handful of food, or stab like a fork, push food off of that fork, or dispense loose food items gradually, e.g. ‘sprinkling’.  This gripper went on to become the primary end effector for a $1M+ commercial research project


fig 2bsideview

The conical iris gripper was rapid prototyped with 3d printing,  laser cutting,  OEM parts, and a minimum of machining,  over the span of about two weeks with other projects going on. The initial prototype was made using mostly laser cut acrylic and off the shelf parts, with a materials cost of less than $150.