United States Patent 5119693

A damped double flywheel comprises two coaxial inertia masses which are mounted for relative rotation, both against the action of a first series of springs and against the action of a viscous damping means. A damper wheel connects the viscous damping means with the first series of springs, and the latter couple the damper wheel with a first damping control means carried by the first mass. A second series of circumferentially acting springs, of greater stiffness than the first series of springs, couples the damper wheel to a second damping control means which is carried in rotation on the second mass.