A Novel Force-Changeable Underactuated Robot Finger with Self-Adaptive and Joint-Locking Function

The traditional spring-style finger with springs in joints for grasping and cables for extension of the finger cannot provide a huge range of forces in grasping though it can grasp sorts of objects with different sizes and shapes. This paper presents a joint-locking (JL) function for improving the spring-style finger. The JL function is realized by cables and friction units embedded in the finger. A novel spring-style finger with JL function is proposed and named SJL finger. The SJL finger activates the joint-locking function to keep the configuration of the finger after self-adaptive grasping in order to increase grasping force. Analysis results show that design of the SJL finger is effective.