Electronically controlled frequency dependent damping

Abstract

A gas damper includes a gas pressurized working chamber and valving within the piston to control flow of the gas through the piston. A system is in communication with the working chamber to control the gas pressure within the working chamber in order to control the damping characteristics of the damper. An electronic control unit is utilized to control the opening and closing of the valving within the piston to also control the damping characteristics of the damper.

1 . A damper comprising: 
 a pressure tube forming a working chamber;    a gas disposed within said working chamber;    a first piston disposed within said working chamber, said first piston dividing said working chamber into an upper working chamber and a lower working chamber;    a system for selectively controlling pressure of said gas disposed within said working chamber.    
     
     
         2 . The damper according to  claim 1  further comprising: 
 a valve for controlling flow of said gas through said first piston; and    a control unit in communication with said valve, said control unit controlling opening and closing of said valve.    
     
     
         3 . The damper according to  claim 1  further comprising a piston rod connected to said first piston and extending through said working chamber, said system including selectively controlling a diameter of said piston rod.  
     
     
         4 . The damper according to  claim 1  wherein said system comprises: 
 a source of pressurized gas in communication with said working chamber; and    a control unit for controlling flow of gas between said source and said working chamber.    
     
     
         5 . The damper according to  claim 4  further comprising: 
 a valve for controlling flow of said gas through said first piston; and    a control unit in communication with said valve, said control unit controlling opening and closing of said valve.    
     
     
         6 . The damper according to  claim 1  wherein said system comprises: 
 a reservoir of gas in communication with said working chamber;    a first valve disposed between said reservoir and said upper working chamber;    a second valve disposed between said reservoir and said lower working chamber; and    a control unit in communication with said first and second valves, said control unit controlling opening and closing of said first and second valves.    
     
     
         7 . The damper according to  claim 6  further comprising: 
 a valve for controlling flow of said gas through said first piston; and    a control unit in communication with said valve, said control unit controlling opening and closing of said valve.    
     
     
         8 . The damper according to  claim 6  further comprising a third valve disposed within said reservoir, said third valve dividing said reservoir into an upper reservoir and a lower reservoir, said first valve being in communication with said upper reservoir, said second valve being in communication with said lower reservoir, said third valve being in communication with said control unit, said control unit controlling opening and closing of said third valve.  
     
     
         9 . The damper according to  claim 8  further comprising: 
 a valve for controlling flow of said gas through said first piston; and    a control unit in communication with said valve, said control unit controlling opening and closing of said valve.    
     
     
         10 . The damper according to  claim 1  wherein said system comprises: 
 a first reservoir of gas in communication with said upper working chamber;    a first valve disposed between said first reservoir and said upper working chamber;    a second reservoir of gas in communication with said lower working chamber;    a second valve disposed between said second reservoir and said lower working chamber; and    a control unit in communication with said first and second valves, said control unit controlling opening and closing of said first and second valves.    
     
     
         11 . The damper according to  claim 10  further comprising: 
 a valve for controlling flow of said gas through said first piston; and    a control unit in communication with said valve, said control unit controlling opening and closing of said valve.    
     
     
         12 . The damper according to  claim 1  further comprising: 
 a second piston disposed within said upper working chamber, said second piston defining an intermediate working chamber disposed between said upper and lower working chambers;    a first valve for controlling flow of said gas through said first piston;    a second valve for controlling flow of said gas through said second piston; and    a control unit in communication with said first and second valves, said control unit controlling opening and closing of said first and second valves.    
     
     
         13 . The damper according to  claim 1  wherein said system comprises an air spring having a pressurized gas in communication with said working chamber.  
     
     
         14 . The damper according to  claim 13  further comprising: 
 a valve for controlling flow of said gas through said first piston; and    a control unit in communication with said valve, said control unit controlling opening and closing of said valve.    
     
     
         15 . The damper according to  claim 13  further comprising a booster disposed between said air spring and said working chamber.  
     
     
         16 . The damper according to  claim 15  further comprising: 
 a valve for controlling flow of said gas through said first piston; and    a control unit in communication with said valve, said control unit controlling opening and closing of said valve.    
     
     
         17 . The damper according to  claim 1  wherein said system comprises: 
 a hydraulic actuator having a pressurized liquid;    a converter in communication with said pressurized liquid of said hydraulic actuator and said working chamber.    
     
     
         18 . The damper according to  claim 17  wherein said converter comprises a hydraulic cylinder and a gas cylinder.  
     
     
         19 . The damper according to  claim 17  further comprising: 
 a valve for controlling flow of said gas through said first piston; and    a control unit in communication with said valve, said control unit controlling opening and closing of said valve.    
     
     
         20 . A damper comprising: 
 a pressure tube forming a working chamber;    a gas disposed within said working chamber;    a first piston disposed within said working chamber;    a second piston disposed within said working chamber, said first and second pistons dividing said working chamber into an upper working chamber, an intermediate working chamber and a lower working chamber;    a first valve for controlling the flow of said gas though said first piston;    a second valve for controlling flow of said gas through said second piston; and    a control unit in communication with said first and second valves, said control unit controlling opening and closing of said first and second valves.