Evolution of a Novel Finger Mechanism for Robust Industrial End Effectors

This paper presents design for a finger mechanism that has evolved from the stringent requirement of ruggedness and reliability in an industrial application. The paper initially describes the need for a special purpose end effector to operate in a constrained environment and then takes through the various stages of design modifications that were required to ensure safety and reliability. This resulted into a rigid link finger design, which is adaptive to different shapes and operated by a single actuator providing up to 3 degrees of freedom to the finger. A number of such finger mechanisms can be assembled together in different configurations to design special purpose end effectors. This paper covers two such designs and briefly discusses the grasping and control issues associated with the limited number of actuators built into the end effector, and evaluates their suitability in industrial environments. The design overcomes limitations of majority of existing tendon based end effectors requiring a large number of actuators to be controlled thus meeting the space and safety requirements for constrained industrial applications.