Flexible monotube valve with digressive performance and independent low speed orifice

A piston valve assembly for regulating the flow of fluid through a mono-tube fluid vehicle damper, said assembly comprising:

• a piston rod;
• a piston end having opposing first and second surfaces secured to said piston rod by a connector;
• a first outer annular seat spaced radially from said piston rod and extending from said first surface;
• a first fluid passageway connecting a first opening between said piston rod and said first outer annular seat and said second surface for providing fluid communication therebetween;
• a first blow-off valve having a hollow cylindrical portion with a first flange extending transversely from an end thereof with said first flange adjacent and abutting said first outer annular seat when said first blow-off valve is in a closed position, said piston rod and connector securing said blow-off valve to said piston end, said first blow-off valve movable to an open position away from said first surface;
• a first low speed bypass valve interposed between said first passageway and said second surface for permitting fluid to exit said first fluid passageway past said first blow-off valve when said first blow-off valve is in said closed position;
• and
• a first helical spring engaging said first blow-off valve for biasing said first blow-off valve to said closed position,
• wherein said first low speed bypass valve comprises first and second discs interposed between said first and second surfaces within a portion of said first fluid passageway, and a spring member for biasing said discs away from one another, said first disc having an orifice and said second disc movable toward said first disc when said spring member is compressed for permitting fluid to move past said second disc through said first fluid passageway and exit through said orifice.