Extensible drive connections

Claim 1

AN EXTENSIBLE SHAFT ASSEMBLY COMPRISING INNER AND OUTER SHAFT MEMBERS ADAPTED TO MOVE AXIALLY, ONE WITHIN THE OTHER, BETWEEN PREDETERMINED LIMIT POSITIONS, SAID SHAFT MEMBERS HAVING MATING AXIALLY EXTENDING GROOVE SPACED, GROUPS OF BALLS RECEIVED IN EACH OF SAID GROOVES SPACES IN ROLLING CONTACT WITH THE SURFACES THEREOF, A PAIR OF RING MEMBERS EXTENDING AROUND SAID INNER SHAFT MEMBER ADJACENT THE OPPOSITE ENDS OF SAID GROOVE SPACES, EACH OF SAID RING MEMBERS CARRYING PINS EXTENDING INTO SAID GROOVE SPACES TOWARDS THE CENTER THEREOF, SPRINGS COILED AROUND EACH OF SAID PINS AND COMPRESSED BETWEEN SAID RING MEMBER AND THE ADJACENT END OF ONE OF SAID GROUPS OF BALLS, SAID SPRINGS BEING EFFECTIVE TO MAINTAIN SAID GROUPS OF BALLS AXIALLY CENTERED IN SAID GROOVE SPACES WHEN SAID INNER AND OUTER SHAFT MEMBERS OCCUPY A CENTER POSITION BETWEEN SAID LIMIT POSITIONS AND MEANS INDEPENDENT OF SAID RING MEMBERS AND SAIDD GROUPS OF BALLS FOR MAINTAINING SAID INNER AND OUTER SHAFT MEMBERS IN CONCENTRIC RELATION.