High velocity compression damping valve

A shock absorber comprising:

• a pressure tube forming a first fluid chamber;
• a working fluid disposed within said first fluid chamber;
• a piston body slidably disposed within said first fluid chamber, said piston body dividing said first fluid chamber into an upper working chamber and a lower working chamber;
• a second fluid chamber in communication with said lower working chamber;
• a first fluid valve assembly disposed between said lower working chamber and said second fluid chamber, said first fluid valve assembly allowing direct fluid flow from said second fluid chamber to said lower working chamber while prohibiting fluid flow from said lower working chamber directly to said second fluid chamber;
• a second fluid valve assembly disposed between said lower working chamber and said second fluid chamber, said second fluid valve assembly prohibiting fluid flow from said second fluid chamber to said lower working chamber while allowing fluid flow from said lower working chamber to said second fluid chamber;
• a pressure sensitive valve assembly including a movable member spaced from the first and second fluid valve assemblies, said movable member of said pressure sensitive valve assembly including at least one hole extending therethrough, and said pressure sensitive valve assembly being disposed between said lower working chamber and said second fluid chamber, and wherein:
• said pressure sensitive valve assembly operates independently from a position of said piston body within said first fluid chamber;
• a first surface on said movable member of said pressure sensitive valve assembly always being in direct fluid contact with working fluid disposed within said second fluid chamber such that fluid pressure in said second fluid chamber acts directly on said first surface of said pressure sensitive valve assembly;
• a second surface of said movable member of said pressure sensitive valve assembly being in direct fluid contact with working fluid disposed within said lower working chamber;
• movement of said movable member of said pressure sensitive valve assembly causing said pressure sensitive valve assembly to change from an open position to a closed position, said pressure sensitive valve assembly then restricting fluid flow through said second fluid valve assembly when said pressure sensitive valve assembly is in said closed position such that fluid flow from said lower working chamber to said second fluid chamber is limited by an area of said hole in said movable member;
• said pressure sensitive valve assembly being operable to move between said open and closed positions to control fluid flow through said second fluid valve assembly based upon a pressure differential between pressure of said working fluid in said second fluid chamber reacting against said second surface of said movable member and pressure of said working fluid in said lower working chamber reacting against said first surface of said movable member;
• the shock absorber further comprising:
• a secondary valve assembly controlling fluid flow through said pressure sensitive valve assembly when said pressure sensitive valve assembly is in said closed position.

A shock absorber comprising:

• a pressure tube forming a first fluid chamber;
• a working fluid disposed within said first fluid chamber;
• a piston body slidably disposed within said first fluid chamber, said piston body dividing said first fluid chamber into an upper working chamber and a lower working chamber;
• means for defining a second fluid chamber in communication with said lower working chamber;
• a first fluid valve assembly disposed between said lower working chamber and said second fluid chamber, said first fluid valve assembly allowing direct fluid flow from said second fluid chamber to said lower working chamber while prohibiting fluid flow from said lower working chamber directly to said second fluid chamber;
• a second fluid valve assembly disposed between said lower working chamber and said second fluid chamber, said second fluid valve assembly prohibiting fluid flow from said second fluid chamber to said lower working chamber while allowing fluid flow from said lower working chamber to said second fluid chamber;
• a pressure sensitive valve assembly different from the first and second fluid valve assemblies disposed between said lower working chamber and said second fluid chamber, said pressure sensitive valve assembly including a movable member having a hole forming a fluid passage therethrough;
• wherein
• said pressure sensitive valve operates independently from a position of said piston body within said first fluid chamber;
• a first surface of said pressure sensitive valve assembly always being in direct contact with working fluid disposed within said second fluid chamber;
• a second surface of said pressure sensitive valve assembly being in direct contact with working fluid disposed within said lower working chamber;
• said pressure sensitive valve assembly is movable from an open position to a closed position based only upon a pressure differential between pressure of said working fluid in said second fluid chamber and pressure of said working fluid in said lower working chamber, said pressure sensitive valve assembly using said hole to limit fluid flow through said second fluid valve assembly when said pressure sensitive valve assembly is in said closed position;
• the shock absorber further comprising:
• a secondary valve assembly controlling fluid flow through said pressure sensitive valve assembly when said pressure sensitive valve assembly is in said closed position.