| abstract |
The engagement pressure of a friction clutch 601 in series with a variable-ratio friction gear 610 is controlled, together with the engagement force in the friction gear, such that the friction clutch and not the friction gearing will slip when torque shocks occur. The engagement forces in both clutch and gearing are controlled in dependence on the the transmitted torque. The friction gearing can be either a pair of pulleys interconnected by a belt 604 or can have members in rolling frictional contact. The clutch may be after the friction gearing rather than before it. |