Non-singular industrial robot wrist

Abstract

The end of a robot arm includes two links, a first or inner link supported rotatably about a central axis and an end link at which a tool is carried. Located between the links are a rod and a tube whose longitudinal axes are concentric. Each of four gimbal rings is used as a member of a universal joint that connects the links, the rod and the tube. The links are connected by two universal joints in series, and the rod connects these joints. The links are also connected by two other universal joints in series and the tube connects this second pair of joints. The first and second pairs of universal joints connected in series are connected to one another in parallel. Gimbal rings rotatably supported on the tube and on the links for angular movement about yaw axis provide rotational support for the links and the connecting rod about the pitch axis. Actuating rods connected to the inner set of gimbal rings produce articulation of the wrist about these axis when the rods are actuated. Angular pitch displacement and angular yaw displacement are equalized between the inner set of gimbal rings and the outer set of gimbal rings by tension members. Alternatively, continuously meshing gear wheel portions equalize yaw and pitch rotational displacement, respectively.

Dependencies are inferred from the claim text.