Tunable hydraulic valve for shock absorber

A direct acting hydraulic shock absorber comprising:

• a pressure cylinder having a valved piston reciprocably disposed therein,
• a reserve tube coextensive of and surrounding said pressure cylinder and defining a fluid-containing reservoir therein,
• upper and lower generally cup-shaped end caps closing the opposite ends of said reservoir,
• valve means adjacent said lower end cap for controlling fluid flow between said pressure cylinder and said reservoir,
• said valve means comprising a valve assembly having a plurality of deflectable apertured valve disks including a first deflectable apertured valve disk and a second deflectable apertured valve disk, said valve assembly being variably responsive to selected ranges of fluid pressure differentials between said pressure cylinder and said reserve tube to provide a plurality of fluid flow paths between said pressure cylinder and said reservoir,
• wherein a first selected range of fluid pressure differentials deflects said backing disk providing a first fluid flow path through the respective apertures of said first valve disk and said second valve disk and a second selected range of fluid pressure differentials deflects both said first valve disk and said second valve disk providing a second fluid flow path through said valve assembly.

A method for controlling the flow of hydraulic fluid from an upper end of a pressure cylinder of a shock absorber, through a reciprocable piston disposed therein, into a lower end of said pressure cylinder, said method comprising the steps of:

• providing a tunable valve assembly disposed upon said piston, and
• providing a plurality of fluid flow paths through said tunable valve assembly defined in part by a plurality of apertured deflection valve disks including a first deflatable apertured valve disk, a second deflectable apertured valve disk and a backing disk;
• deflecting said backing disk so as to provide a first fluid flow path through the respective apertures of said first deflectable apertured valve disk and said second deflectable apertured valve disk during a first selected range of fluid pressure differentials;
• and
• deflecting both said first valve disk and said second valve disks providing a second fluid flow path through said valve assembly during a second selected range of fluid pressure differentials.