Pulleys 1, 2, 3 and 4 rotate about fixed axes A, B, C and D. Pulley 6 is rigidly attached to (or integral with) pulley 2, and pulley 5 to pulley 3. Open belt 7 runs over pulleys 1 and 6, and open belt 9 over pulleys 3 and 4. Crossed belt 8 runs over pulleys 2 and 5. The total transmission ratio from pulley 1 to pulley 4 is i₁₄=-((R₆R₅R₄)/(R₁R₂R₃)) where R₁, R₂, R₃, R₄, R₅ and R₆ are the radii of pulleys 1, 2, 3, 4, 5 and 6. Pulleys 1 and 4 rotate in opposite directions.
$3517$SFL,BD$