Abstract: The invention contemplates a universal coupling wherein rotatable input and output members are coupled both (1) for universal flexible accommodation of the instantaneous angular orientation (misalignment) of their rotary axes about a single point of axis intersection and (2) for gear-tooth drive engagement in the transmission of torque from one to the other of these members. The result is to achieve both (1) and (2) above (a) for a greater range of axis misalignment than is possible with universal couplings of the past, (b) with greater uniformly high torque transmission as a function of incremental rotation of the coupling members, and (c) with symmetry of torque-transmitting force development with respect to the axes of rotation.