Patent ID: 7063200

Claim:
A pulsation dampening apparatus used for a hydraulic clutch operation system which has a hydraulic circuit comprising: a housing which has a dampening chamber interposed in the hydraulic circuit; a dampening assembly accommodated in the housing, said dampening assembly including: a working unit having a vibration dampening member substantially adjacent the dampening chamber for alleviating pulsations generated in hydraulic fluid in the dampening chamber and a circular fulcrum at an outer periphery of the vibration dampening member and on a side of the vibration dampening member opposite the dampening chamber so that portions of the vibration dampening member inward of the outer periphery can deform into areas inward of the circular fulcrum, and an elastic retainer on a side of the working unit opposite the dampening chamber, the elastic retainer being elastically preloaded from its free state to retain the working unit in the housing; and a force conversion mechanism which converts a spring-back force of the elastic retainer in said preloaded state to urge the circular fulcrum of the working unit elastically against the vibration dampening member and towards the dampening chamber.