A Robot Gripper with Differential and Hoeckens Linkages for Straight Parallel Pinch and Self-Adaptive Grasp

For grasp modes, parallel pinch is one of the significant way of them. The traditional parallel pinching and self-adaption device moves with arc-shaped motion at phalanx terminal, requiring the assistance of an industrial robotic arm for lifting motion, making using it with inconvenience. So as to settle the issue, Hoeckens finger - a kind of novel robot finger is modeled and produced. The Hoeckens linkage mechanism is adopted for achieving the linear motion of the terminal joint in this finger. The mechanism of differential on phalanx surface is set for achieving shape self-adaptation of two phalanxes. And the parallel four-bar has the ability to keep attitude. Above designs achieve the underactuated gripper. After grasping force and motion analysis of Hoeckens fingers, the optimized parameters can be attained. Then The Hoeckens gripper is produced. With results of experiments, the Hoeckens gripper achieves the straight parallel pinching and self-adaption grasping function, with large grasp range, stable grasp effect. The Hoeckens gripper can be used to capture objects in more conditions.