Cross-shaped link 6 turns about fixed axis A and carries four friction wheels located in different planes. Stepped friction wheel 5 rotates about fixed axis B. Link 6 has four separate indexed positions so that wheel 1 can engage step a, wheel 2 step b, wheel 3 step c, or wheel 4 step d. Thus rotation can be transmitted with any one of four different speed ratios.
$3378$SmF,ML$