Torsion damping device with movement transmitting element

A torsion damping device, comprising a hub, at least one transverse hub flange encircling the hub and being connected therewith by meshing means with play;

• first circumferentially-acting elastic means disposed between the hub flange and the hub, at least one flange coupled to the hub flange by second circumferentially-acting elastic means, said at least one flange encircling the hub but not being connected to it;
• an interposing element comprising two movable plates, responsive to centrifugal force, mounted for movement between a standby position in which the plates are inactive and, above a set speed of rotation, an operating position, in which they intervene between the hub and the hub flange for at least one direction of rotation, by driving in the direction of rotation at least a part of the second circumferentially-acting elastic means other than those which normally act between them;
• and return means operable to urge said movable plates towards their standby position;
• and wherein said movable plates are connected to one another by at least one transmission element, said transmission element being mounted for rotation relative to the plates such that a radial displacement of one of the movable plates causes rotation of the transmission element and a corresponding radial displacement in the opposite direction of the other movable plate.