Spherical joint for coupling three or more links together at one point

Abstract

A spherical joint for coupling three or more links together at one point. The joint includes a bail and a hollow spherical body wrapping the ball therein. The ball is movable in the hollow spherical body. An upper link inserted into and fixed to the hollow spherical body through an upper link insertion opening formed on the hollow spherical body. Lower links are connected to the hollow spherical body through lower link insertion openings, wherein the number of the lower links correspond to that of the hollow spherical body. Link support discs are set within a gap between outer surface of the central ball and inner surface of the hollow spherical body and fixed to each end of the lower link, and all the axes of the lower links and the upper link are coincident with a center point of the ball.