Universal joints and couplings

Claim 1

A UNIVERSAL JOINT COMPRISING A SHAFT, AN OUTER AND AN INNER MEMBER MOUNTED CONCENTRICALLY WITH AND AXIALLY SURROUNDING SAID SHAFT, SAID INNER MEMBER SUPPORTED ON AND CONNECTED TO SAID SHAFT, SAID OUTER AND INNER MEMBERS HAVING A PLURALITY OF REGULARLY CIRCULARLY SPACED, MATCHING INNER AND OUTER GROOVES RESPECTIVELY, A PLURALITY OF BALLS, A BALL LOCATING CAGE MOUNTED INTERMEDIATE THE OUTER AND THE INNER MEMBERS FOR LOCATING SAID BALLS EQUIDISTANTLY SPACED WITH THEIR CENTRES ON A COMMON PLANE, EACH BALL ENGAGED IN A GROOVE OF SAID OUTER AND INNER MEMBERS, THE MOUNTING FOR SAID CAGE CONSISTING OF SPHERICAL BEARING CONTACT BETWEEN THE INTERNAL AND EXTERNAL SURFACES OF THE CAGE AND THE INNER AND OUTER MEMBERS RESPECTIVELY, THE CAGE THUS BEING MOUNTED FOR CONTROLLING THE ARTICULATION CENTRE OF THE JOINT, SAID GROOVES BEING AXIAL PARALLEL, EXTENDING STRAIGHTLY IN THE AXIAL DIRECTION OF SAID MEMBERS AND PROVIDING CROSS-SECTIONAL SHAPES WHICH AT LEAST IN PART CLOSELY FIT THE DIAMETERS OF THE BALLS THEREIN WITH MINIMUM SLIDING FRICTION AND HIGH ROLLING EFFICIENCY, WHEREBY THE BALLS ROLL IN THEIR GROOVES TO STEER THE CAGE ACCURATELY INTO THE BISECTOR PLANE.