Hydraulic damper and valve structure

A hydraulic damper having an oil chamber partitioning member such as a piston or a bottom member or the like and having a passage therein connecting two oil chambers partitioned by said partitioning member, and a damping force generating device disposed in said partitioning member, said damping force generating device comprising a flexible valve disc means adapted to open or close said passage for generating a damping force against the oil flowing across the device in opposite directions, a fixed outer periphery supporting valve seat on said partitioning member for engaging with the outer periphery of said valve disc means on one face of said valve disc means, a fixed inner periphery supporting valve seat on said partitioning member for engaging with the inner periphery of the valve disc means on the other face of said valve disc means, and a movable spring loaded valve seat sealingly engaged between said other face of said valve disc means around the entire periphery thereof and said partitioning member for restricting the effective pressure receiving area of said valve disc means and movably mounted on said partitioning member for limited movement in the direction of movement of said valve disc means while remaining in sealing engagement with said valve disc means when the valve disc means deflects in one direction under the spring loading thereof for delaying the opening of said passage and movable with the valve disc means against the spring loading thereof when the valve disc means deflects in the other direction.