Abstract: A transmission is described which provides a continuously and infinitely variable number of ratios within a finite range of gear ratios. The transmission comprises two rotary disk assemblies, one of which is driven by an input shaft, and the other of which drives an output shaft to which varying loads may be applied. The two disk assemblies are connected by a coupling mechanism, such as a coupling ring, which rotates in response to the rotation of the input disk assembly, causing the output disk assembly to rotate in the same direction. The coupling ring rides on contact pads located within slots in each of the disk assemblies, which contact pads form two circles with continuously variable diameters with respect to the center of each disk assembly. The contact pads move along slots of differing angles on two disks within each disk assembly at a position determined by the intersection of the angled slots.