Control valve for shock absorbers

A direct acting shock absorber for damping the movement of the body of an automobile comprising:

• a pressure cylinder forming a working chamber having first and second portions operable to store damping fluid;
• a piston disposed within said pressure cylinder between said first and second portions of said working chamber;
• a fluid reservoir operable to store damping fluid;
• first valve means for permitting damping fluid to flow from said first portion of said working chamber to said fluid reservoir during movement of said piston in a first direction;
• second valve means for permitting damping fluid to flow from said fluid reservoir to said second portion of said working chamber during movement of said piston in a second direction;
• a rod guide having a first flow passage fluidly communicating with said first portion of said working chamber, said first flow passage selectively fluidly communicating with said reservoir through a first orifice in said rod guide;
• and
• a first valve disk, said first valve disk operable to control the flow of damping fluid from said first flow passage through said first orifice, an additional flow passage means in said rod guide in communication with said reservoir and said first valve disk such that the pressure of the hydraulic fluid in said additional flow passage means being operable to bias said valve disk in a first direction.

A method for controlling the flow of damping fluid between first and second portions of a working chamber of a direct acting shock absorber comprising the steps of:

• permitting damping fluid in the first portion of said working chamber to fluidly communicate with first valve means for controlling the flow of damping fluid;
• permitting damping fluid in the second portion of said working chamber to fluidly communicate with second valve means for controlling the flow of damping fluid;
• permitting said first and second valve means to fluidly communicate with a reservoir of damping fluid;
• allowing damping fluid in said reservoir to flow in one direction between said first valve means and said second valve means during compression and rebound of said shock absorber, and said shock absorber including a rod guide having a first flow passage fluidly communicating with said first portion of said working chamber, said first flow passage selectively fluidly communicating with said reservoir through a first orifice in said rod guide, said first valve means including a first valve disk, said first valve disk operable to control the flow of damping fluid from said first flow passage through said first orifice controlling opening of said first valve disk with an additional flow passage means in said rod guide in communication with said reservoir and said first valve disk such that the pressure of the damping fluid in said additional flow passage means being operable to bias said valve disk in a first direction.

A shock absorber comprising:

• a pressure tube symmetrically disposed about an axis, said pressure tube forming a working chamber having upper and lower portions;
• a reservoir tube for storing hydraulic fluid, said reservoir tube disposed concentric to and radially extended from said pressure tube;
• a flexible valve member operable for controlling the flow of hydraulic fluid between said upper portion of said working chamber and said reservoir tube;
• second valve means for allowing flow of said hydraulic fluid from said reservoir tube into said lower portion of said working chamber and for preventing flow of said fluid from said lower portion of said working chamber into said reservoir tube;
• a piston slidably disposed between and separating said upper and lower portions of said working chamber, said piston allowing restricted flow of hydraulic fluid between said upper and lower portions of said working chamber;
• an elongated piston rod having first and second ends, said first end being attached to said piston, said second end of said elongated piston rod extending along the axis of said pressure tube through said upper portion of said working chamber and out one end of said pressure tube;
• a rod guide disposed between said piston rod and said pressure tube;
• a first annular seal disposed around said piston rod;
• an annular seal retainer disposed concentrically about said piston rod and adjacent to said rod guide;
• a first annular cavity disposed between said piston rod, said first annular seal, and said seal retainer;
• a second annular cavity disposed between said piston rod and said annular seal retainer;
• a third annular cavity disposed between said annular seal retainer and said rod guide;
• a first flow passage communicating with said reservoir tube;
• a second flow passage communicating with said first annular cavity and said first flow passage;
• a third flow passage communicating with said first annular cavity and said second annular cavity;
• a fourth flow passage communicating with said second annular cavity and said third annular cavity;
• a fifth flow passage communicating with said reservoir tube and said valve member;
• a sixth flow passage communicating with the upper portion of said working chamber and said valve member;
• and
• a second annular seal disposed in said second annular cavity, said second annular seal operably to restrict movement of said flexible valve member during rebound of said shock absorber by controlling the flow of damping fluid between said third annular cavity and said reservoir tube.

A shock absorber comprising:

• a pressure tube symmetrically disposed about an axis, said pressure tube forming a working chamber having upper and lower portions;
• a reservoir tube for storing hydraulic fluid, said reservoir tube disposed concentric to and radially extended from said pressure tube;
• a flexible valve member operable for controlling the flow of hydraulic fluid between said upper portion of said working chamber and said reservoir tube, said flexible valve member is defined as a deflectable membrane;
• second valve means for allowing flow of said hydraulic fluid from said reservoir tube into said lower portion of said working chamber and for preventing flow of said fluid from said lower portion of said working chamber into said reservoir tube.
• a piston slidably disposed between and separating said upper and lower portions of said working chamber, said piston allowing restricted flow of hydraulic fluid between said upper and lower portions of said working chamber;
• and
• an elongated piston rod having first and second ends, said first end being attached to said piston, said second end of said elongated piston rod extending along the axis of said pressure tube through said upper portion of said working chamber and out one end of said pressure tube.