Vibration damper with adjustable damping force

A shock absorber comprising:

• a cylinder defining a chamber therein, said cylinder containing a damping fluid;
• a piston rod sealingly projecting into said cylinder and being axially displaceable with respect to said cylinder;
• a piston being attached to said piston rod, said piston being slidably disposed within said cylinder to sealingly divide said cylinder into first and second chambers;
• means for permitting fluid communication between said first and second chambers;
• said means for permitting fluid communication being disposed in at least a portion of said piston, said means for permitting fluid communication comprising:
• means for dividing the damping medium into a main flow and a side flow;
• a first spring-loaded main stage valve body;
• a second spring-loaded main stage valve body;
• a control chamber being defined between said first main stage valve body and said second main stage valve body;
• first inlet means for directing fluid from said first chamber to said control chamber through said first main stage valve body upon axial displacement of said piston in a first direction;
• second inlet means for directing fluid from said second chamber to said control chamber through said second main stage valve body upon axial displacement of said piston in a second direction, the second direction being opposite the first direction;
• means for permitting axial displacement of:
• said first main stage valve body towards said second main stage valve body during flow of damping fluid through said first inlet means;
• and
• said second main stage valve body towards said first main stage valve body during flow of damping fluid through said second inlet means;
• said means for permitting fluid communication between said first and second chambers comprising a pilot stage valve configured for activating said first and second main stage valve bodies, said pilot stage valve comprising said means for permitting axial displacement of said first main stage valve body and said second main stage valve body;
• said pilot stage valve comprising:
• a non-return valve arrangement, said non-return valve arrangement comprising at least one non-return valve;
• a pair of control cross-sections having means for being controlled in alternation with respect to one another;
• said pilot stage valve being configured to permit the side flow, as a function of the direction of the side flow, to pass one of said control cross-sections and one said non-return valve;
• and
• said one non-return valve being configured to open in the direction of the side flow upon passing of the side flow therethrough.

A shock absorber comprising:

• a cylinder defining a chamber therein, said cylinder containing a damping fluid;
• a piston rod sealingly projecting into said cylinder end being axially displaceable with respect to said cylinder;
• a piston being attached to said piston rod, said piston being slidably disposed within said cylinder to sealingly divide said cylinder into first and second chambers;
• means for permitting fluid communication between said first and second chambers;
• said means for permitting fluid communication being disposed in at least a portion of said piston, said means for permitting fluid communication comprising:
• a first main stage valve body;
• a second main stage valve body;
• a control chamber being defined between said first main stage valve body and said second main stage valve body;
• first inlet means for directing fluid from said first chamber to said control chamber through said first main stage valve body upon axial displacement of said piston in a first direction;
• second inlet means for directing fluid from said second chamber to said control chamber through said second main stage valve body upon axial displacement of said piston in a second direction, the second direction being opposite the first direction;
• a pilot stage valve configured for activating said first and second main stage valves;
• said pilot stage valve comprising:
• at least one non-return valve;
• and
• at least one control cross-section;
• said pilot stage Valve being configured to permit the side flow to pass through at least a portion of each of:
• said at least one non-return valve;
• and
• said at least one control cross-section;
• as a function of the direction of the side flow.

Method of operating a shock absorber, the shock absorber comprising:

• a cylinder defining a chamber therein, the cylinder containing a damping fluid;
• a piston rod sealingly projecting into the cylinder and being axially displaceable with respect to the cylinder;
• a piston being attached to the piston rod, the piston being slidably disposed within the cylinder to sealingly divide the cylinder into first and second chambers;
• the first chamber being disposed adjacent the piston rod and the second chamber being disposed further away from the piston rod than is the first chamber;
• said method comprising the steps of:
• providing means for permitting fluid communication between the first and second chambers;
• disposing the means for permitting fluid communication in at least a portion of the piston;
• said step of providing the means for permitting fluid communication comprising the steps of:
• providing a first spring-loaded main stage valve body;
• providing a second spring-loaded main stage valve body;
• defining a control chamber being between the first main stage valve body and the second main stage valve body;
• providing first inlet means for directing fluid from the first chamber to the control chamber through the first main stage valve body upon axial displacement of the piston in a first direction;
• providing second inlet means for directing fluid from the second chamber to the control chamber through the second main stage valve body upon axial displacement of the piston in a second direction, the second direction being opposite the first direction;
• providing means for permitting axial displacement of the first main stage valve body towards the second main stage valve body during flow of damping fluid through the first inlet means;
• providing means for permitting axial displacement of the second main stage valve body towards the first main stage valve body during flow of damping fluid through the second inlet means;
• providing means for dividing the damping medium into a main flow and a side flow;
• providing a damping valve device;
• and
• said step of providing a damping valve device comprising the steps of:
• providing a damping valve body and first and second main stage valves, the first main stage valve comprising the first main stage valve body, and the second main stage valve comprising the second main stage valve body;
• and
• providing a pilot stage valve configured for activating the first and second main stage valves, the pilot stage valve comprising the means for permitting axial displacement of the first main stage valve body and the second main stage valve body;
• said method further comprising the additional steps of:
• displacing the piston in the first direction;
• performing the following steps during displacement of the piston in the first direction:
• directing fluid, with the first inlet means, from the first chamber to the control chamber through the first main stage valve body;
• and
• axially displacing the first main stage valve body towards the second main stage valve body;
• said step of axially displacing the first main stage valve body comprising the step of activating the first main stage valve with the pilot stage valve by permitting axial displacement of the first main stage valve body;
• displacing the piston in the second direction;
• performing the following steps during displacement of the piston in the second direction:
• directing fluid, with the second inlet means, from the second chamber to the control chamber through the second main stage valve body;
• and
• axially displacing the second main stage valve body towards the first main stage valve body;
• said step of axially displacing the second main stage valve body comprising the step of activating the second main stage valve with the pilot stage valve by permitting axial displacement of the second main stage valve body;
• providing outlet means for directing damping fluid between the control chamber and the first and second chambers;
• and
• providing actuator means for adjustably controlling the flow of damping fluid through the outlet means.