Patent ID: 7654906

Claim:
A damper with a trigger plate in which a sleeve made from a metal plate of a magnetic body, and an elastic body are interposed between a hub attached to a rotating shaft and an annular mass body arranged at an outer peripheral side of said hub, wherein one end portion of said sleeve is bent outwardly in a radial direction along an end surface of said annular mass body so as to form a collar portion, said trigger plate is magnetized at a predetermined pitch in a circumferential direction and is integrally provided on an outer surface of said collar portion of said sleeve, said trigger plate has magnetized layers made of a rubber-like elastic material or a synthetic resin material, in which fine magnetic powder is uniformly mixed, that are bonded through vulcanization on said outer surface of said collar portion of said sleeve at said predetermined pitch in said circumferential direction, and said magnetized layers have different magnetic poles alternately in the circumferential direction.