characterised by the use of a magnetisable powder or liquid as friction medium between the rotary members

Full Title

Gearings for conveying rotary motion with variable gear ratio, or for reversing rotary motion, by friction between rotary members (control of change-speed or reversing-gearings conveying rotary motion F16H59/00 - F16H63/00) > characterised by the use of a magnetisable powder or liquid as friction medium between the rotary members