Friction cone c is keyed to shaft 1 and rotates about fixed axis A-A. Friction cone e, identical to cone c, is keyed to shaft 3 and rotates about fixed axis B-B. Roller 2 rotates about fixed axis C-C and can slide along this axis on feather key f. The roller is in contact with cones c and e at points E and F. The transmission ratio from shaft 1 to shaft 3 is i₁₃=ω₁/ω₃=n₁/n₃=(rd+(R-r)(a+m))/(Rd-(R-r)*a) where ω₁, ω₃, n₂ and n₃ are the angular velocities and speeds (in rpm) of shafts 1 and 3, R and r are the radii of the large and small ends of the cones, d is the length of an element of the cones, a is the variable distance from point D at the large end of cone c to point E of contact of roller 2 and cone c, and constant m=2r₂*((R-r)/d) with r₂ being the radius of roller 2.
$3471$CF,IV$