US Patent 7172509 Damper mechanism and damper disk assembly

A damper mechanism or a damper disk assembly realizing a low rigidity using a pair of elastic members is provided to achieve a further low rigidity in a region with small torques. The damper mechanism has a drive member 52, a driven member 53, a pair of first torsion springs 58A and 58B, and a second torsion spring 59. The springs 58A and 58B are functionally provided in series with each other in a rotational direction. The spring 59 is functionally provided in parallel with the springs 58A and 58B in such a way that the spring 59 is compressed in the rotational direction after the springs 58A and 58B are compressed to a certain angle when the drive member 52 and the driven member 53 rotate relative to each other.