Patent ID: 8752685

Claim:
A lock-up device for a torque converter for transmitting torque and simultaneously absorbing and attenuating torsional vibration, the lock-up device comprising: an input rotary member; an output rotary member; an elastic member being configured to couple the input rotary member and the output rotary member in a rotational direction; and a support member rotatably disposed relatively to the input rotary member and the output rotary member, the support member including a support part supporting the elastic member, and an engaging part integrally formed with the support part, the engaging part engaged with the elastic member in the rotational direction, the support part including an outer peripheral side support portion being configured to support an outer peripheral side of the elastic member, the outer peripheral side support portion including an outer peripheral end which has a curvature, the curvature continuously becoming more reduced as being further away from the engaging part in the rotational direction.